Fuel exchange system and fuel supply system for fuel systems

Abstract

A system for exchanging of different fuels that can be used for operation of an engine. The system includes a fuel exchange unit, a control and an exchange return conduit. The fuel exchange unit is configured to deliver a first fuel at pressure into the injections system given a switched-off engine, in order to replace a second fuel, which is located in the injection system, with the first fuel. A fuel delivery system includes a media converter which includes a deflectable element. The media converter is driven by a drive unit via the fluid by way of the fluid being able to be led at a varying pressure to the media transformer via a first feed conduit, and is configured to deliver the fuel via a pumping effect.

Claims

1. A system for the delivery of a combustible, comprising: a conduit system, in which a fluid and a combustible, which is different than said fluid, can be led; a media transformer that is configured to deliver the combustible through the conduit system; a connection via which the media transformer can be connected to a drive unit, wherein the drive unit is configured to move the fluid through the conduit system and wherein the connection is configured to feed the fluid to the media transformer; wherein the media transformer comprises a deflectable element, a first volume for the fluid, a second volume for the combustible and a first feed conduit, via which the fluid can flow into the first volume, wherein the media transformer is configured to convert a varying pressure of the fluid that flows into the first volume via the first feed conduit into a deflection of the deflectable element such that a pumping effect upon the combustible arises, said pumping effect being suitable for a supply of the engine with the combustible.

2. The system according to claim 1, wherein the deflectable element is one of a membrane or a piston.

3. The system according to claim 1, wherein the first volume perpendicularly to a deflection direction of the deflectable element in the first volume comprises a first profile and the second volume perpendicularly to a deflection direction of the deflectable element in the second volume comprises a second profile, wherein the deflectable element comprises a first end-face that has the first profile, and a second end-face that has the second profile, and wherein the first profile and the second profile are configured for the system to be operable as a pressure transformer and/or delivery rate transformer.

4. The system according to claim 1, wherein apart from the first feed conduit, the media transformer comprises a first discharge conduit as well as a second feed conduit and a second discharge conduit, wherein the first feed conduit/discharge conduit is connected to the first volume and the second feed conduit/discharge conduit is connected to the second volume.

5. The system according to claim 4, wherein the fluid can be brought into the first volume via the first feed conduit and the combustible into the second volume via the second feed conduit, wherein the fluid in the first volume is at a first pressure and the combustible in the second volume is at a second pressure and wherein the media transformer is configured to use a pressure difference between the first pressure and the second pressure for deflecting the deflectable element and for delivering the combustible in the conduit system and/or for a change of the second pressure.

6. The system according to claim 5, wherein the system is configured for the fluid being brought at least temporarily to a first pressure by the drive unit, said first pressure being higher than the second pressure, and for the combustible flowing out of the second volume and/or for the change of the second pressure corresponding to a pressure increase.

7. The system according to claim 6, wherein the system comprises at least one of the following elements: a return that connects the first discharge conduit to an inlet of the drive unit and/or to a fluid reservoir for storage of the fluid; a controllable valve that regulates the flow of the fluid via the return; a combustible container for storing the combustible, said combustible container being connected to the media transformer via the second feed conduit; a fuel facility return conduit that connects the second feed conduit to the combustible container; a feed-conduit-side check valve that prevents a backflow of the combustible into the combustible container via the second feed conduit; an aperture or a pressure regulator, which ensures that excess combustible that is located in an inlet region of the media transformer is led back into the combustible container via the fuel facility return conduit.

8. The system according to claim 1, further comprising a control that is configured to control at least one valve of the system.

9. The system according to claim 1, wherein the system comprises at least two media transformers that are connected in parallel and operated asynchronously to one another.

10. The system according to claim 9, wherein the two media transformers are realised as a hydraulic block comprising a first block part with a left chamber of the first block part and with a right chamber of the first block part, a second block part with a left chamber of the second block part and with a right chamber of the second block part, and a third block part that separates the first block part from the second block part, wherein the left chamber of the first block part is the first volume of the first media transformer, the right chamber of the second block part the second volume of the first media transformer, the right chamber of the first block part the first volume of a second media transformer and the left chamber of the second block part the second volume of the second media transformer, wherein the deflectable element comprises a first piston which separates the left chamber of the first block part from the right chamber of the first block part, a second piston that separates the left chamber of the second block part from the right chamber of the second block part and comprises a piston connection, wherein the piston connection forms a rigid connection between the first and second pistons.

11. The system according to claim 1, wherein the deflectable element is a deflectable separating element, which, in the media transformer, separates the fluid from the combustible.

12. The system according to claim 1, wherein the media transformer comprises a surrounding wall and a cooling bore that is located therein, that can be fed with the combustible or the fluid and that is configured to cool at least a part of the media transformer.

13. The system according to claim 12, wherein the cooling bore can be fed with liquid combustible, comprises an aperture and/or nozzle and/or a pressure regulator and is configured to cool at least a part of the media transformer by way of a cooling effect which occurs on evaporation of the liquid combustible.

14. The system according to claim 1, wherein the system is configured as a theft protection and comprises a receiver, a portable transmitter and a control, wherein the control is configured to switch the valves of the system such that the combustible, which is delivered by a combustible delivery pump, and the fluid, which is delivered by a fluid delivery pump, are transported back into a combustible container and into a fluid reservoir, respectively, when the receiver is not in contact with the transmitter.

15. The system according to claim 1, further comprising an operating console and a control that is configured to acquire at least one operating parameter of the system, wherein the control is configured to transmit the operating parameter to the operating console, wherein the operating console is configured to display transmitted operating parameters and wherein the operating console is configured to forward commands, which are inputted via it, to the control.

16. The system according to claim 15, wherein the system is configured such that the transmission of the at least one operating parameter to the operating console and/or its display on the operating console and/or the forwarding of a command from the operating console to the control presupposes an authorization authentication.

17. The system according to claim 1, wherein the system can be incorporated into a fuel facility that supplies an engine which can be operated with different fuels, with fuel, and wherein the fluid is a first fuel and the combustible is a second fuel.

18. The system according to claim 1, wherein the system is configured for the drive unit to subject the fluid to the varying pressure, at which the fluid flows via the first feed conduit into the first volume.

19. The system according to claim 1, wherein at least one feed-conduit-side control valve and at least one discharge-conduit-side controllable valve are configured such that the fluid, which flows into the first volume via the first feed conduit, has a pressure that varies.

20. A fuel facility comprising a fluid reservoir for a fluid, a combustible container for a combustible, a drive unit and a conduit system, comprising a system according to claim 1.

21. The fuel facility according to claim 20, wherein the drive unit is a fuel high-pressure pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiment examples of the invention are hereinafter described by way of figures. In the figures, the same reference numerals indicate the same or analogous elements. With reference to the Figures:

(2) FIG. 1 shows a schematic representation of a fuel facility with an installed system according to a first aspect of the invention, wherein the fuel facility supplies a four-cylinder combustion motor with a direct injection of fuel;

(3) FIG. 2 shows a schematic representation of the fuel facility according to FIG. 1 with an alternative system according to the first aspect of the invention;

(4) FIG. 3 shows a schematic representation of a second fuel facility with an installed system according to the first aspect of the invention, wherein the fuel facility is again a four-cylinder combustion motor with a direct injection of fuel;

(5) FIG. 4 shows a schematic representation of a fuel facility with an installed system according to a second aspect of the invention, wherein the fuel facility supplies a four-cylinder combustion motor with a direct injection of fuel;

(6) FIG. 5 shows a schematic representation of a media transformer which additionally operates as a pressure and delivery rate transformer;

(7) FIG. 6 shows a schematic representation of an alternative embodiment of a fuel facility with an installed system according to the second aspect of the invention, the system including two media transformers;

(8) FIG. 7 shows a schematic representation of a fuel facility with an installed double media transformer with two fronts;

(9) FIG. 8 shows a schematic representation of a further alternative embodiment of a fuel facility with an installed system according to the second aspect of the invention;

(10) FIG. 9 shows a schematic representation of a further alternative embodiment of a fuel facility with an installed system according to the second aspect of the invention;

(11) FIG. 10 shows a schematic representation of a system according to the second aspect of the invention, the system including a double media transformer which is realised as a hydraulic block;

(12) FIG. 11 shows a schematic representation of a system according to the second aspect of the invention, the system being hydraulically operated.

DETAILED DESCRIPTION OF THE INVENTION

(13) FIG. 1 shows a schematic representation of a fuel facility 20 with an installed system according to a first aspect of the invention. The engine, which is supplied with fuel via the fuel facility 20, is a four-cylinder combustion motor with a direct injection, which is operated with a first fuel 22 (e.g. petrol) and a second fuel 23 (e.g. LPG). For this, the fuel facility includes the following elements before the installation of the system for the exchange of the fuels: A first fuel container 1 for the first fuel 22, a first fuel delivery pump 2, which transports the first fuel 22 from the first fuel container 1 into a conduit system of the fuel facility; a second fuel container 11 for the second fuel 23, a second fuel delivery pump 12, which transports the second fuel 23 from the second fuel container 11 into the conduit system of the engine; a fuel high-pressure pump 3 with a pressure regulator 4; a fuel distributor 16, which is configured to switch between a feed of the first and the second fuel, to the fuel high-pressure pump 3. The fuel distributor 16 can further be configured to ensure a return of the second fuel 23 from the fuel high-pressure pump 3 to the second fuel container 11 via a fuel facility return conduit 25.

(14) The engine further includes an injection system 8 with injection nozzles 9 and a pressure sensor 10 for the monitoring and control of the pressure in the injection system.

(15) In the shown embodiment, the system for the exchange of fuels includes a fuel exchange unit 17 with a pressure accumulator 7 and with a pressure accumulator valve 6, an exchange return conduit 24, a return valve 15 and a check valve 5, wherein the latter as a rule is integrated in the fuel distributor 16.

(16) The pressure accumulator 7 and the pressure accumulator valve 6 are arranged upstream of the injection system 8 of the engine and downstream of the fuel high-pressure pump 3 or rather the pressure regulator 4 respectively, by way of them being connected to a corresponding part of the conduit system of the fuel facility.

(17) The exchange return conduit 24 connects the mentioned part of the conduit system of the fuel facility between the fuel high-pressure pump 3 or rather the pressure regulator 4, and the injection system 8, to the fuel facility return conduit 25. For this, the exchange return conduit 24 includes a high-pressure-side connection 26 onto the mentioned part of the conduit system of the fuel facility and a second connection 27 onto the fuel facility return conduit 25. The return valve 15 controls the flow of a fuel via the exchange return conduit 24 by way of it being integrated into the exchange return conduit 24.

(18) The check valve 5 prevents fuel, which is led via the exchange return conduit 24, from penetrating into the fuel distributor 16.

(19) A fuel facility which is as shown in FIG. 1, with an installed system according to the first aspect of the invention can be operated as follows: Operation of the engine by the first fuel 22: the first fuel delivery pump 2 delivers first fuel 22 out of the first fuel container 1 into the conduit system of the fuel facility 20. The fuel distributor 16 leads this fuel to the fuel high-pressure pump 3 and to the pressure regulator 4, where the first fuel 22 is brought to the operating pressure (system pressure) which is required for the first fuel. The first fuel 22 which is at the operating pressure is then fed to the injection system 8 via the conduit system of the fuel facility. On operation of the engine with the first fuel 22, the second fuel delivery pump 12 is inactive and the return valve 15 is closed. The pressure accumulator 7 is filled with the first fuel 22 during the operation of the engine. This corresponds to a first step for the exchange of the fuel while using the system according to the first aspect of the invention. The pressure accumulator valve 6 is opened for this. The pressure accumulator valve 6 is closed after filling the pressure accumulator 7. Operation of the engine by the second fuel 23: the second fuel delivery pump 12 delivers second fuel 23 out of the second fuel container 11 into the conduit system of the fuel facility 20. The fuel distributor 16 leads this fuel to the fuel high-pressure pump 3 and to the pressure regulator 4 where the second fuel 23 is brought to the operating pressure (system pressure) that is necessary for the second fuel. The second fuel 23, which is at the operating pressure, is then fed to the injection system 8 via the conduit system of the fuel facility. The fuel facility return conduit 25, which is led via the fuel distributor 16, ensures that excess second fuel is led back into the second fuel container. Furthermore, the fuel facility return conduit 25 ensures a return of second fuel given cavitation in the inlet region of fuel high-pressure pump 3. The return valve 15 as well as the pressure accumulator valve 6 is closed on operation of the engine with the second fuel 23. Discharge of the second fuel 23 via the exchange return conduit 24: this corresponds to the second step for the exchange of the fuel amid the use of the system according to the first aspect of the invention. Herein, after switching off the engine, the second fuel 23, which is located in the injection system 8 and in parts of the conduit system of the fuel facility, is discharged into the second fuel container 11 by way of the return valve 15 opening. The first and the second fuel delivery pump as well as the fuel high-pressure pump 3 and the injection system 8 are inactive and the pressure accumulator valve 6 is closed. Alternatively, a discharge of the second fuel 23 into a storage container 18 for the second fuel 23 is possible. The second fuel 23, which is stored in the storage container 18, can be delivered again in the direction of the injection system on later operation of the engine with the second fuel 23. This alternative embodiment is characterised in FIG. 1 by dot-dashed lines. Filling of the injection system 8 with first fuel 22 from the pressure accumulator 7: this corresponds to the third step for the exchange of the fuel amid the use of the system according to the first aspect of the invention. For this, the return valve 15 is closed before the pressure accumulator valve 6 is opened. The first and second fuel pump as well as the fuel high-pressure pump 3 and the injection system 8 are inactive.

(20) FIG. 2 shows a schematic representation of a fuel facility 20 according to FIG. 1, in which facility an alternative system according to the first aspect of the invention is installed by way of the system as a central element including a boost pump 117 with a boost pump inlet 118 and a boost pump outlet 119, instead of the pressure accumulator 7.

(21) The boost pump is connected to the high-pressure region of the fuel facility 20 via the high-pressure-side connection 26 and is secured against overpressure at the boost pump outlet 119 by a boost pump check valve 121.

(22) In the shown embodiment, the boost pump obtains the first fuel 22 from a reservoir 120, which is designed as a separate container and which is filled during the operation of the engine, and thus of the first fuel delivery pump 2. However, the boost pump can also be integrated into the reservoir 120.

(23) Alternative embodiments for the supply of the boost pump 117 without a reservoir 120 are represented by way of dot-dashed lines. Herein, it is the case of a direct supply out of the first fuel container 1 or a supply via an access to a region of the conduit system, in which region the first fuel 22 can be fed. The latter can necessitate a switching-on of the first fuel delivery pump 2.

(24) The boost pump 117 can moreover be cascadable, which is to say that several pumps are connectable one after the other for the purpose of increasing the pressure.

(25) FIG. 2 as a possible supplement further shows a pressure accumulator 7 and a pressure accumulator valve 6, which can be applied for increasing the pressure of the first fuel 22, which flows out of the boost pump outlet 119 in the direction of the injection system 8.

(26) FIG. 3 shows a schematic representation of a second embodiment of a fuel facility 20 with an installed system according to the first aspect of the invention. As in FIG. 1, the engine is a four-cylinder combustion motor with a direct injection, which is operated via the fuel facility 20 with a first fuel 22 (e.g. petrol) and a second fuel 23 (e.g. LPG). The main difference to the fuel facility according to FIG. 1 lies in the first and the second fuel being brought to the operating pressure in each case via a separate fuel high-pressure pump each in combination with a pressure regulator. The shown fuel facility with the installed system according to the first aspect of the invention therefore has the following differences to the fuel facility according to FIG. 1: A second fuel high-pressure pump 13 with a second pressure regulator 14 is present apart from a first fuel high-pressure pump 3 with the first pressure regulator 4. The fuel facility return conduit 25 connects an outlet of the second pressure regulator 14 to the second fuel container 11 in a direct manner.

(27) The operation of the fuel facility 20, which is shown in FIG. 3, with the installed system according to the first aspect of the invention as well as the exchange of the fuels is analogous to that of the engine with the installed system according to the first aspect of the invention, which is shown in FIG. 1.

(28) FIG. 3 further shows an alternative embodiment for filling the pressure accumulator 7. For this, the system includes a bypass to the pressure accumulator valve 6, wherein a check valve 5 ensures that the first fuel 22 via this bypass only flows into the pressure accumulator 7 but not out of this. The pressure accumulator valve 6 is then always in the closed state, except for when the first fuel 22, which is located in the pressure accumulator 7 is to be discharged into the injection system.

(29) FIG. 4 shows a schematic representation of a fuel facility 20 with an installed system according to the second aspect of the invention. The fuel facility 20 with the installed system on the one hand, via a fuel high-pressure pump 40, which in the shown embodiment, also carries out the function of a drive unit 31, transports a first fuel 22 (e.g. petrol) from a first fuel container 1 to an injection system 8. On the other hand, the fuel facility 20 via a media transformer 32 transports a second fuel 23 (e.g. LPG) from a second fuel container 11 to the injection system 8. As in FIGS. 1 to 3, the engine, which is supplied via the fuel facility 20, is a four-cylinder combustion engine with a direct injection.

(30) The fuel facility includes the following elements before the installation of the system: the first fuel container 1 with a first fuel delivery pump 2, which transports the first fuel 22 from the first fuel container 1 into the conduit system of the fuel facility: the fuel high-pressure pump 40 with a pressure regulator 46 for the first fuel 22; the injection system 8 with injection nozzles 9 and with a pressure sensor 10 for the monitoring and control of the pressure in the injection system 8; an engine-side control 52, which also controls the operation of the fuel facility before the installation of the system.

(31) In the shown embodiment, the system includes: The media transformer 32, which can be supplied with the first fuel 22 via a first feed conduit/discharge conduit pair (first feed conduit 33.1, first discharge conduit 33.2) and which is configured, amid the use of a second feed conduit/discharge conduit pair (second feed conduit 34.1, second discharge conduit 34.2), to bring the second fuel 23 to the operating pressure and to transport it to the injection system 8 via the conduit system. A first feed conduit connection 48, a first discharge conduit connection 49, a second feed conduit connection 50 and a second discharge conduit connection 51. Herein, the first feed conduit connection 48 and the second discharge conduit connection 51 access a part of the conduit system of the fuel facility, the part being located between the fuel high-pressure pump 40 and the injection system 8, wherein the second discharge conduit connection 51 is arranged downstream of the first feed conduit connection 48. The first discharge conduit connection 49 accesses a part of the of the conduit system of the fuel facility, the part being located between the first fuel container 1 and the fuel high-pressure pump 40. The second feed conduit connection 50 ensures a connection of the media transformer 32 to the second fuel container 11, wherein this connection is arranged downstream of a possibly present fuel facility return conduit 25 or is realised via a T-piece. A switch-over valve 43, with which one can switch between a supply of the injection system 8 with the first fuel 22 and a supply with the second fuel 23. In the shown embodiment, the switch-over valve 43 is arranged in the conduit system between the first feed conduit connection 48 and the second discharge conduit connection 51. In particular a feed conduit connection 48, which is designed as a 3/2 way valve, is alternatively advantageous. A controllable valve 30, with which the discharge of the first fuel 22 out of the media transformer 32 via a return 44 to the inlet of the fuel high-pressure pump 40, or rather to the first fuel container 1 is controllable. The controllable valve 30 is further configured to control the flow of first fuel 22 through the media transformer 32. The controllable valve 30 switches quickly, i.e. at the rate (cycle) of the pressure regulator 46 of the fuel high-pressure pump 40. A feed-conduit-side check valve 39.1, by way of which it is ensured that no fuel can leave the media transformer 32 via the second feed conduit 34.1. A discharge-conduit-side check valve 39.2, by way of which it is ensured that no fuel flows into the media transformer 32 via the second discharge conduit 34.2. An aperture 47 or a pressure regulator, via which excess second fuel in the region of the second feed conduit 34.1 can be led back in the direction of the second fuel container 11. Further, a return of the second fuel can be ensured via the aperture 47 or via the pressure regulator, in the case of cavitation (formation of gas). A control 21 is configured to control the system. In particular, the control 21 regulates all valves of the system that are necessary for the operation of the fuel facility with the integrated system, the operation being described hereinafter. A high-pressure-side check valve 54, which ensures that no fuel flows out of the media transformer 32 in the direction of the fuel high-pressure pump 40 via the first feed conduit 33.1 If, as is shown in FIG. 4, the fuel high-pressure pump 40 executes the function of the drive unit 31, then the high-pressure-side check valve 54 is integrated into the fuel high-pressure pump 40.

(32) The system can additionally include the following elements, depending on whether the system is used for retrofitting to a bi-fuel fuel facility or whether the system is installed into a fuel facility, which is already retrofitted for bi-fuel: the second fuel container 11 with a second fuel delivery pump 12; a conduit system, which connects an outlet of the second fuel delivery pump 12 to the second feed conduit 34.1 of the media transformer 32; the fuel facility return conduit 25.

(33) In the shown embodiment, the media transformer 32 includes a first volume 35 and a second volume 36, which are separated in a liquid-tight manner by a piston 38.

(34) Instead of the piston 38, the first volume 35 can also be separated from the second volume 36 in a liquid-tight manner by a membrane 37 (as is shown for example in FIG. 9).

(35) The first fuel 22 can be led into and out of the first volume 35 via the first feed conduit/discharge conduit pair. The second fuel 23 can be led into and out of the second volume 36 via the second feed conduit/discharge conduit pair.

(36) An engine as is shown in FIG. 4, with an installed system according to the second aspect of the invention functions as follows: The first fuel delivery pump 2 transports the first fuel 1 at a preliminary pressure to an inlet 41 of the fuel high-pressure pump 40; The fuel high-pressure pump 40 brings the first fuel 22 to the operating pressure, which as a rule is greater than 40 bar. The fuel high-pressure pump is driven by the engine itself via a camshaft. By way of this, the pressure of the first fuel 22 varies in a cycle, which is predefined by the motor and which, in particular, is dependent on the motor speed and the number of cams on the camshaft. The switch-over valve 43 is opened (or rather the 3/2 way valve leads the first fuel 22 in the direction of the injection system 8) and the controllable valve 30 is closed, on operation of the engine with the first fuel 22. The system of the second fuel is inactive due to this and the engine is driven by the first fuel 11, as was the case with the fuel facility before the installation of the system. On operation of the engine with the second fuel 23, the switch-over valve 43 is closed, or rather the 3/2 way valve leads the first fuel 22 in the direction of the first feed conduit 33.1 of the media transformer 32. The first fuel 22 can be diverted into the first volume 35 under a cyclically varying high pressure by way of this. Furthermore, the second fuel delivery pump 12 transports the second fuel 23 via the second feed conduit 34.1 into the second volume 36 where a cyclical pressure increase take space. Herein, a cycle includes the following steps: 1. Initial situation: the first volume 35 is filled with the first fuel 22 and the second volume 36 is filled with the second fuel 23, wherein the pressure in the two volumes is identical and the piston 38 assumes a basic position. The controllable valve 30 is closed. 2. The first fuel 22 enters at high pressure into the first volume 35 via the first feed conduit 33.1. The piston 38 is deflected in the direction of the second volume 36 by way of this and the second fuel 23 is subjected to pressure. 3. The second fuel 23 exits at pressure out of the second volume 36 in the direction of the injection system 8 via the second discharge conduit 34.2. The feed-conduit-side check valve 39.1 prevents an outflow of the second fuel 23 via the second feed conduit 34.1 4. The fuel high-pressure pump 40 no longer delivers first fuel 22 in the direction of the media transformer 32 and the controllable valve 30 briefly opens, by which means first fuel 22 exits out of the first volume 35. Second fuel 23 can enter into the second volume 36 via the second feed conduit 34.1 on account of this and the piston can return into its basic position. 5. The controllable valve 30 closes and the cycle can begin afresh. The system is activated in the cycle of the engine, given a combustion motor in the cycle of the motor speed, in order to permit a smooth running of the engine.

(37) FIG. 5 shows a schematic representation of a media transformer 32, which has dimensions, by way of which the media transformer 32 can be operated as a pressure and delivery rate transformer. For this, the piston 38 (or the membrane 37) towards the first volume 35 includes a first end-face 67 and towards the second volume 36 includes a second end-face 68. Apart from a first spatial extension 69, which is perpendicular to the first end-face 67 and is variable by way of the movement of the piston 38 (or by the deflection of the membrane 37), the first volume 35 is given by a first circular profile with a first diameter 65. Analogously, apart from a second spatial extension 70, which is perpendicular to the second end-face 68 and which is variable by way of the movement of the piston 38 (or by the deflection of the membrane 37), the second volume 36 is given by a second, circular profile with a second diameter 66.

(38) In the shown embodiment, the surface area of the first end-face 67 is smaller than the surface area of the second end-face 68. On account of this, the media transformer 32 acts as a pressure reducer after the connection via the first feed conduit/discharge conduit (33.1, 33.2), or the second feed conduit/discharge conduit (34.1, 34.2), i.e. the pressure (second pressure), which is produced in the second volume, is lower than the pressure (first pressure), which prevails in the first volume. Furthermore, the quantity of second fuel, which is delivered by the shown media transformer 32, is greater than the quantity of first fuel, which is delivered by the first volume, i.e. the delivery rate is increased.

(39) FIG. 6 shows a fuel facility 20, into which a system according to the second aspect of the invention is installed, wherein the system in the shown embodiment include a first media transformer 32.1 and a second media transformer 32.2. The two media transformers are connected in parallel and interact such that the engine is sufficiently supplied with the second fuel 23, although both media transformers operate in a switching range, which is lower or the same as the cycling of the fuel high-pressure pump 40. The two media transformers operate asynchronously for this, i.e. the deflection of the piston 38.1 of the second media transformer 32.2 and therefore the delivery of the second fuel 23 by the second media transformer 32.2 begins as soon as the piston 38.1 (or the membrane) of the first media transformer 32.1 is deflected maximally in the direction of the second volume 36.1 of the first media transformer 32.1. While the second media transformer 32.2 delivers the second fuel 23, the piston 38.1 of the first media transformer 32.1 returns into its non-deflected basic position and the second fuel 23 flows into the enlarging second volume 36.1 of the first media transformer 32.1. The piston 38.1 of the first media transformer 32.1 then at the latest assumes its non-deflected basic position when the piston 38.2 of the second media transformer 32.2 is deflected maximally in the direction of the second volume 36.2 of the second media transformer 32.2, by which means the first media transformer 32.1 can assume the delivery of the second fuel 23 while the piston 38.2 of the second media transformer 32.2 can return into its non-deflected basic position amid the inflow of the second fuel 23 into the second volume 36.2 of the second media transformer 32.2.

(40) In order to ensure an asynchronous interaction of the two media transformers, the system according to FIG. 6 additionally includes a first feed-conduit-side control valve 55.1, which is attached to the first feed conduit 33.1.1 of the first media transformer 32.1, and a second feed-conduit-side control valve 55.2, which is attached to the first feed conduit 33.1.2 of the second media transformer 32.2. Disregarding this, the two media transformers are integrated into the fuel facility 20 analogously to FIG. 4 and they are operated as previously described (amongst others switch-over valve 43, controllable valve 30.1 of the first media transformer 32.1, first feed conduit connection 48, second discharge conduit connection 51, controllable valve 30.2 of the second media transformer 32.2, fuel facility return conduit 25, return 44 etc.).

(41) Alternatively, an asynchronous interaction of the two media transformers can also be achieved by an integral construction manner of the media transformers. FIG. 7 shows an embodiment to that effect, by way of example of a double media transformer 80 with two fronts. In the shown embodiment, the piston 38.1 of the first media transformer 32.1 (or of its deflectable element) forms a first front and the piston 38.2 of the second media transformer 32.2 (or its deflectable element) a second front. The piston 38.1 of the first media transformer 32.1 is herein connected to the piston 38.2 of the second media transformer 32.2 via a rigid connection 81. The second volume 36.1 of the first media transformer 32.1 is separated from the second volume 36.2 of the second media transformer 32.2 by a separating wall 82, wherein the rigid connection 81 of the two pistons is moveably mounted in the separating wall 82 by way of a guide such that no pressure equalisation takes place between the two second volumes or between a second volume and the surroundings. The feed conduit and discharge conduit into/out of the first volume of one of each media transformer (first feed conduit/discharge conduit) are each located in a region of the media transformer, which lies at the side of the respective piston, which is away from the separating wall 82. This region consequently defines the respective first volume (first volume 35.1 of the first media transformer 32.1, first volume 35.2 of the second media transformer 32.2). The feed conduit and discharge conduit into/out of the second volume of one of each media transformer (second feed conduit/discharge conduit) are each located in a region of the media transformer, which lies between the separating wall 82 and the respective piston. Such a media transformer is operated by way of fluid (first fuel) being alternately admitted at pressure into the first volume 35.1 of the first media transformer 32.1 and into the first volume 35.2 of the second media transformer 32.2.

(42) Supplementarily or alternatively to embodiments with two (or more) media transformers, it is also possible to dimension the two media transformers differently, in particular to select a different ratio between the first and the second diameter (see also FIGS. 5 and 8), and possibly to ensure different activation times of the valves, which control the first or the second media transformers, via the control 21, so that the second fuel 23, which flows out of the first media transformer 32.1 in the direction of the injection system 8, has a different pressure and/or different delivery rate per cycle in comparison with the second fuel 23, which flows out of the second media transformer 32.2.

(43) Alternatively, the first and the second volume, or the first and second feed conduit/discharge conduit pair of each media transformer can be swapped.

(44) Embodiments of the media transformer, concerning which the first volume 35 is separated from the second volume 36 by a piston 38 in each case, are shown in FIG. 7. Alternatively, one or both media transformers can operate with a membrane 37 as shown in FIG. 9.

(45) FIG. 8 shows a fuel facility 20, into which a system according to the second aspect of the invention is integrated, wherein it is not a fuel high-pressure pump that serves as a drive unit 31, but another pump 58 which delivers a fluid 60. An example of such a pump is an oil pump, which is driven via a chain drive 57.

(46) Since such pumps 58 as a rule generate no cyclical pressure peaks, the system, which is shown in FIG. 8, includes a first media converter 32.1 and a second media converter 32.2, a first feed-conduit-side control valve 55.1 and a controllable (discharge-conduit-side) valve 30.1 of the first media transformer 32.1 as well as a second feed-conduit-side control valve 55.2 and a controllable (discharge-conduit-side) valve 30.2 of the second media transformer 32.2. The system further includes a fluid reservoir 62 and a return conduit 44, which connects the first volume of the first and second media transformer to the fluid reservoir via the respective (discharge-conduit-side) controllable valve.

(47) Furthermore, in the shown embodiment, the media transformers at the side of their first volume (first volume 35.1 of the first media transformer 32.1, first volume 35.2 of the second media transformer 32.2) are flanged on the drive unit 31, which is designed as a pump 58, and can be supplied with the fluid 60, which is under pressure from the compression space 59 of the pump 58, in a direct manner by way of a pressure conduit 56. A supply via another outlet of the drive unit and/or via a conduit system, which belongs to the drive unit, is likewise possible.

(48) A cyclically varying pressure can be produced at the feed conduit 33.1.1 to the first volume 35.1 of the first media transformer 32.1 and at the feed conduit 33.1.2 to the first volume 35.2 of the second media transformer 32.2 respectively, with the help of the feed-conduit-side control valves (55.1 and 55.2), the (discharge-conduit-side) controllable valves (30.1 and 30.2) as well as a suitably designed control 21. Herein, the two media transformers again operate asynchronously to one another, as is described for example in combination with FIG. 6.

(49) If necessary, a loss of fluid 60 or another use of the fluid 60 can be compensated by the fluid reservoir 62.

(50) The media transformers according to FIG. 8 are further dimensioned such that they additionally operate as pressure transformers with a view to a pressure increase of the combustible 61, which is delivered via the second volume 36.1 of the first media transformer 32.1, or via the second volume 36.2 of the second media transformer 32.2, compared to the pressure of the fluid 60.

(51) The combustible 61, which is delivered by the system according to FIG. 8, as is shown in FIG. 4 gets from a combustible container 63 into the second volume 36.1 of the first media transformer 32.1 or into the second volume 36.2 of the second media transformer 32.2 and from there to the injection system 8 of the engine.

(52) Optionally, the fuel facility 20, which is shown in FIG. 8, can include a part-region for the delivery of a second combustible 71. In particular, this part-region includes a second combustible container 72 with a combustible delivery pump 73 and a combustible high-pressure pump 74 with a pressure regulator.

(53) FIG. 9 shows a fuel facility 20, into which a system according to the second aspect of the invention is integrated and which serves for the supply of a bi-fuel combustion motor with a direct fuel injection. In the shown embodiment, the media transformer 32 has a membrane 37, which separates the first from the second volume. Furthermore, the first volume 35 (analogously to FIG. 8) is supplied directly from the compression space 59 of the fuel high-pressure pump 40 of the first fluid 22 via the pressure conduit 56. The first fuel 22 consequently assumes the function of the fluid 60 and the fuel high-pressure pump 40, which is driven by the combustion motor via the camshaft 45, again functions as the drive unit 31. Herein, first fuel 22, which is located in the compression space 59 of the fuel high-pressure pump 40, is transported in the direction of the first volume 35 of the media transformer 32 at a cycle that is defined by the motor (depending on the number of cams on the camshaft 45). A closure valve 64 decouples the media transformer from the compression space 59 as soon as the engine is operated via the first fuel 22.

(54) A return 44 from the first volume 35 of the media transformer 32 to the inlet of the drive unit 31, the return being controlled by the controllable valve 30, can be done away with on account of this design with a pressure conduit 56, in which the fluid acts as a hydraulic liquid.

(55) The elements of the system that are necessary for the feed of the second fuel 23 to the media transformer 32 and to the injection system 8 as well as the switching between the first and the second fuel are analogous to FIG. 4 in this embodiment

(56) FIG. 10 shows an embodiment of the system 200 according to the second aspect of the invention that includes a double media transformer 80, which is realised as a hydraulic block.

(57) The hydraulic block includes a first block part 201, a second block part 202, a third block part 203 and the deflectable element 204.

(58) The deflectable element 204 includes a first piston 204.1, a second piston 204.2 and a rigid piston connection (piston rod) 204.3. The piston connection 204.3 is led perpendicularly to the end-face of the first and second piston and is led through a guide in the third block part 203.

(59) The first piston 204.1 is configured such that it is guided by a piston bore in the first block part 201. The second piston 204.2 is configured such that it is guided by a piston bore in the second block part 202.

(60) The guides of the piston connection 204.3, of the first piston 204.1 and of the second piston 204.2 include sealings, so that chambers, which are separated from one another, are formed.

(61) In particular, the seals are of such a nature that no liquid exchange takes place between the chambers.

(62) In the shown embodiment, the end-face of the first piston 204.1 is identical to the end-face of the second piston 204.2. However, this is not a necessity for the functioning of the system shown in FIG. 10. In contrast, the two end-faces and possibly an extension of the first and second block part along the movement direction of the delectable element 204 can be different, so that the shown media transformer can also be operated as a pressure transformer and/or delivery rate transformer.

(63) The first piston 204.1 subdivides the first block part 201 into a left chamber 201.1 and into a right chamber 201.2. The summed volume of the left and right chamber is constant, wherein however a movement of the first piston 204.1 can change the relative volume of the left and right chamber.

(64) The second piston 204.2 subdivides the second block part 202 into a left chamber 202.1 and into a right chamber 202.2. The summed volume of the left and right chamber is constant, wherein however a movement of the second piston 204.2 can change the relative volume of the left and right chamber.

(65) The maximal or minimal volume of the left and right chamber as a rule is different due to the piston connection 204.3

(66) In the shown embodiment, the left chamber 201.1 of the first block part 201 corresponds to the first volume of a first media transformer of the double media transformer 80, the right chamber 202.2 of the second block part 202 to the second volume of the first media transformer, the right chamber 201.2 of the first block part 202 to the first volume of the second media transformer of the double media transformer 80 and the left chamber 202.1 of the second block part 202 to the second volume of the second media transformer.

(67) In the embodiment according to FIG. 10, the first block part 201 is configured for the fluid (petrol) and the second block part 202 for the combustible (LPG).

(68) The left and right chambers each include a feed conduit and a discharge conduit.

(69) The feed conduit into the left chamber 201.1 and the feed conduit into the right chamber 201.2 of the first block part 201 are controlled by a first (common) chamber feed conduit valve 220 which is realised as a 3/2-way valve.

(70) The first chamber feed conduit valve 220 is connected at the inlet side to a connection 210 to the outlet of the drive unit (high-pressure pump) and at the outlet side to the left and right chamber of the first block part 201.

(71) The discharge conduit out of the left chamber 201.1 and the discharge conduit out of the right chamber 201.2 of the first block part 201 are controlled by a first (common) chamber discharge conduit valve 221 which is realised as a 3/2 way magnet valve.

(72) The first chamber discharge conduit valve 221 is connected at the inlet side to the left and the right chamber of the first block part 201 and at the outlet side to a return 211 to the fluid reservoir.

(73) The return of fluid out of the first block part 201 into the fluid reservoir is secured via a check valve 217. The check valve 217 has a holding pressure or opening pressure. In particular, it has an opening pressure, which lies above the boiling pressure of the fluid (for example petrol) at the theoretically reachable maximal temperature due to trapped heat, so that a boiling of the fluid in the media transformer is prevented.

(74) If the fluid is petrol, then the opening pressure can be between for example 2 and 5 bar, in particular between 2.7 and 3.5 bar.

(75) The occupation of the connections of the first chamber feed conduit valve 220 and of the first chamber discharge conduit valve 221 is consequently of a nature that the first piston 204.1 is movable in both directions along the axis of the piston connection 204.3 by way of an equally directed switching of these two valves.

(76) Specifically, the occupation of the connections of the first chamber feed conduit valve 220 and of the first chamber discharge conduit valve 221, shown in FIG. 10, leads to the first chamber feed conduit valve 220 leading fluid into the right chamber 201.2 and the first chamber discharge-conduit valve 221 preventing a flow of fluid out of the right chamber and simultaneously permitting a flow of the fluid out of the left chamber 201.1, when both valves are not subjected to current. As a result, the first piston 204 is pressed in the direction of the left chamber 201.1.

(77) With the shown occupation of the connections, a simultaneous subjection of the first chamber feed conduit valve 220 and of the first chamber discharge conduit valve 221 to current leads to the first chamber feed conduit valve 220 leading fluid into the left chamber 201.1 while the first chamber discharge conduit valve 221 permits a discharge of the fluid out of the right chamber 201.2, but prevents a discharge out of the left chamber 201.1. As a result, the first piston is pressed in the direction of the right chamber 201.2.

(78) The feed conduit to the left chamber 202.1 and to the right chamber 202.2 of the second block part 202 as well as the respective discharge conduits each include a check valve (first feed-conduit-side check valve 222, second feed-conduit-side check valve 223, first discharge-conduit-side check valve 224, second discharge-conduit-side check valve 225).

(79) In particular, these check valves are switched such that the combustible can exclusively get into the left chamber 202.1 via the one of the two feed conduits and into the right chamber 202.2 via the other of the two feed conduits. Furthermore, the combustible can flow out of the left chamber 202.1 exclusively via the one of the two discharge conduits and out of the right chamber 202.2 via the other of the two discharge conduits.

(80) The inlets of the feed-conduit-side check valves (222, 223) are connected to a connection 214 to the combustible delivery pump and therefore to the combustible container.

(81) The outlets of the discharge-conduit-side check valves (224, 225) are connected to a connection 215 to the injection system. Supplementraily, the outlets of the discharge-conduit-side check valves (224, 225) are connected to a combustible reservoir connection 213 via a return. A return of combustible into the fuel reservoir via the combustible reservoir connection 213 is controlled by a combustible backflow valve 208.

(82) In the shown embodiment, the switching between the delivery of the combustible (LPG) and the delivery of the fluid (petrol) to the connection 215 to the injection system is again effected via a switch-over valve 207.

(83) The switch-over valve 207 is realised as a 3/2 way magnet valve, which, at the inlet side, is connected to the connection (inlet) 210 to the outlet of the drive unit and, at the outlet side is connected to the first chamber feed conduit valve 220 and to the connection 215 to the injection system. In the shown embodiment, the switch-over valve 207, which is not subjected to current leads fluid to the connection 215 to the injection system.

(84) The embodiment according to FIG. 10 further includes the following optional features that a system in any embodiment according to the second aspect of the invention can have individually or in combinations: The embodiment, which is shown in FIG. 10, includes a combustible return conduit 231 to the combustible reservoir connection 213, the return conduit being designed as a cooling conduit. The combustible return conduit 231 is realised at least partly as a cooling bore 230, which is fed via a cooling nozzle 232, a return orifice and/or a pressure regulator.

(85) The cooling bores 230 are located in the surrounding wall of the hydraulic block. The embodiment, which is shown in FIG. 10, includes a system for the exchange of different fuels, which can be used for operation of an engine, which is to say a system according to the first aspect of the invention. What is shown is a connection 212 to the pressure accumulator, as well as the pressure accumulator valve 206, which is connected upstream of the pressure accumulator. The pressure accumulator valve 206 is connected at the inlet side to the connection 210 to the outlet of the drive unit (high-pressure pump) and to the inlet of the switch-over valve 207. The fuel exchange in the injection system in the shown embodiment is consequently additionally controlled via the switch-over valve 207.

(86) The embodiment, which is shown in FIG. 10, is further suitable for counteracting pressure downturns which occur on switching over the delivery direction, which is to say on switching from a delivery via the left chamber 202.1 of the second block part 202 to a delivery via the right chamber 202.2 of the second block part 202 and vice versa.

(87) This can be realised, for example, by way of the first chamber feed conduit valve 220 and the first chamber discharge conduit valve 221 not operating completely synchronously, but on switching over being subjected to current for a moment such that the feed conduit as well as the discharge conduit of the one of the two chambers of the first block part 201 are closed and the feed conduit as well as the discharge conduit of the other of the two chambers are open.

(88) In the case that the system includes the optional pressure accumulator according to the first aspect of the invention as is shown in FIG. 10 (connection 212 to the pressure accumulator and pressure accumulator valve 206 in FIG. 10), then the pressure downturns can also be counteracted by way of a brief opening of the pressure accumulator valve 206.

(89) In the case that the drive unit is a (petrol) high-pressure pump, the switching of the first chamber feed conduit valve 220 and of the first chamber discharge conduit valve 221 is effected in dependence on the position of the (petrol) high-pressure pump (or of the camshaft) or on delivery or non-delivery of the fluid.

(90) In the embodiment shown in FIG. 10, the system 200 further includes reed contacts 205. These are arranged on the first and second block part such that they activate when the first or the second piston are located in the end position, in particular at maximal deflection.

(91) The switching of the first chamber feed conduit valve 220 and of the first chamber discharge conduit valve 221 is coupled directly or indirectly via the control to the activation of the reed contacts 205.

(92) FIG. 11 schematically shows the feed of an embodiment of the system 200 according to the second aspect of the invention, the system being operated hydraulically and/ordepending on the specific embodimentmechanically. A multitude of components which are necessary with an electronic operation can done away with on account of this.

(93) It is particularly the electrically activated valves of the media transformer, such as for example the controllable valves (30, 30.1, 30.2), the feed-conduit-side control valves (55.1, 55.2), the first chamber feed conduit valve 220 and the chamber discharge conduit valve 221, and the reed contacts 205, which are mentioned in FIGS. 4-10 and which can be done away with.

(94) In the embodiment which is shown in FIG. 11, the system includes a right valve 227 and a left valve 228, which are hydraulically and/or mechanically connected and are applied instead of the first chamber feed conduit valve 220 and the first chamber discharge conduit valve 221.

(95) In particular, the right and the left valve can be arranged within the hydraulic block, in particular in the surrounding wall of the block.

(96) The right and left valve are connected at the inlet side to the switch-over valve 207.

(97) The right valve 227 controls the feed of fluid into the right chamber 201.2 of the first block part 201. The left valve 228 controls the feed of fluid into the left chamber 201.1 of the first block part 201.

(98) The two valves switch in opposite directions, i.e. on operation, one of the two valves is opened and the other valve closed. An operation of the system 200, which is equivalent to the embodiment with the first chamber feed conduit valve 220 and the first chamber discharge conduit valve 221, is possible with this.

(99) In particular, the switching takes space when the first piston 204.1 assumes a maximal deflection, which is defined, for example, by an end stop. In the shown embodiment, there are two maximal deflections of the first piston 204.1 on operation: a first maximal deflection is reached when the volume of the left chamber 201.1 is minimal and the volume of the right chamber 201.2 is maximal. A second maximal deflection is reached when the volume of the left chamber 201.1 is maximal and the volume of the right chamber 201.2 is minimal.

(100) The state given a maximal deflection of the first piston 204.1 is shown in FIG. 11.

(101) In particular, the switching of the valves can be activated by a dynamic pressure that occurs at the maximal deflection.

(102) For example, the two valves can be biased or be biasable by a spring. The biased spring can close a bore that leads into the chamber. Accordingly, a relaxed spring can open the mentioned bore. A reverse configuration is also conceivable.

(103) A mechanical switching, for example by way of the first piston 204.1 in the maximal deflection or shortly before the maximal deflection interacting with a mechanical lever is also possible, alternatively or supplementarily to a hydraulic switching which in particular is activated via the dynamic pressure.

(104) In particular, a control current which is dependent on the state of the mechanical lever can define the state (open or closed) of the right valve 227 and of the left valve 228. For example, the control current can effect a transition of the spring from the relaxed into the biased state and vice versa.

(105) Neither the hydraulic or mechanical switching of the media transformer nor the previously described measures for preventing pressure downturns are restricted to an embodiment of the system according to FIGS. 10 and 11. In contrast, both can be applied alone or in combination, in each embodiment of the system.