Valve for adjusting a cooling fluid flow for piston cooling

Abstract

A valve for adjusting a cooling fluid flow from a fluid source to a plurality of injection nozzles for cooling a plurality of pistons of an internal combustion engine is provided. The valve has a fluid duct for connecting the fluid source to the plurality of injection nozzles, and a valve element which is arranged so as to be movable, in particular displaceable, in order to change a flow cross-section of the fluid duct. The valve element can be moved into a first position, in which the flow cross-section is not influenced by the valve element.

Claims

1. A valve for adjusting a cooling fluid flow from a fluid source to a plurality of injection nozzles for cooling a plurality of pistons of an internal combustion engine, comprising: a fluid duct for connecting the fluid source to the plurality of injection nozzles; and a valve element configured to be arranged so as to be movable in order to change a flow cross-section of the fluid duct, wherein the valve element can be moved into a first position, in which the flow cross-section is not influenced by the valve element, wherein the valve element has a control face, wherein the cooling fluid acts on the control face in order to displace the valve element so that the valve element is displaced in accordance with the fluid pressure of the cooling fluid, wherein the valve is a straight-way valve, wherein the control face is arranged in a control fluid chamber which is arranged outside the fluid duct, and a supply duct directs cooling fluid from upstream of the valve element into the control fluid chamber, and wherein the valve element is moved with increasing fluid pressure of the cooling fluid in the control fluid chamber in a direction towards the first position so that the flow cross-section is increased, and/or the valve element is moved with decreasing fluid pressure of the cooling fluid in the control fluid chamber in a direction counter to the first position so that the flow cross-section is reduced.

2. The valve according to claim 1, wherein: the valve element in the first position allows the cooling fluid flow to flow through the fluid duct substantially without any loss of pressure, and/or the valve element in the first position does not bring about any pressure loss of the cooling fluid flowing through the fluid duct.

3. The valve according to claim 1, wherein the valve element is positioned in the first position outside the fluid duct.

4. The valve according to claim 1, wherein the fluid duct has an opening, through which the valve element can be moved.

5. The valve according to claim 1, wherein the valve is a piston valve.

6. The valve according to claim 1, wherein: the control face extends perpendicularly to a displacement axis of the valve element.

7. The valve according to claim 6, wherein: the valve is a corner valve, and the control face is an end face of the valve element.

8. The valve according to claim 1, further comprising a leakage duct for cooling fluid which has escaped from the fluid duct.

9. The valve according to claim 1, wherein the valve element is pretensioned counter to the first position, by a resilient element.

10. The valve according to claim 1, wherein the valve element can be moved between the first position and a second position, in which the flow cross-section is at a minimum or zero.

11. The valve according to claim 10, wherein the second position is delimited by a stop for the valve element.

12. A device for cooling a plurality of pistons of an internal combustion engine, comprising: a plurality of injection nozzles which are provided without individual fluid valves; a fluid source; and a valve according to claim 1, which is provided in fluid connection downstream of the fluid source and upstream of the plurality of injection nozzles.

13. The device according to claim 12, wherein the fluid source is an oil pump.

14. A motor vehicle comprising a device for cooling a plurality of pistons of an internal combustion engine according to claim 12.

15. A motor vehicle comprising a valve for adjusting a cooling fluid flow according to claim 1.

16. The valve according to claim 1, wherein the valve is a throttle valve.

17. The motor vehicle according to claim 15, wherein the motor vehicle is a utility vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-described preferred embodiments and features of the invention can be freely combined with each other. Additional details and advantages of the invention will be described below with reference to the appended drawings, in which:

(2) FIG. 1 is a schematic illustration of a device for cooling pistons of an internal combustion engine;

(3) FIG. 2 is a graph which shows two piston cooling lines in accordance with an engine speed;

(4) FIG. 3 shows a valve having a deployed valve element according to a first embodiment of the present disclosure;

(5) FIG. 4 shows the valve having a retracted valve element according to the first embodiment of the present disclosure;

(6) FIG. 5 shows a valve having a deployed valve element according to a second embodiment of the present disclosure; and

(7) FIG. 6 shows a valve having a retracted valve element according to the second embodiment of the present disclosure.

DETAILED DESCRIPTION

(8) The embodiments shown in the Figures at least partially correspond to each other so that similar or identical components are indicated with the same reference numerals and reference may also be made to the description of the other embodiments or Figures for the explanation thereof in order to avoid repetition.

(9) FIG. 1 shows a device 10 for cooling and lubricating a plurality of pistons 12 of an internal combustion engine. The internal combustion engine may be provided, for example, in a motor vehicle, in particular a utility vehicle, for driving it. The utility vehicle may be, for example, a bus or a lorry.

(10) The device 10 has a fluid reservoir 14, a fluid pump 16, a fluid cooler 18, a fluid filter 20, a valve 22; 122 and a plurality of injection nozzles (piston cooling nozzles) 24.

(11) The fluid reservoir 14 may be constructed, for example, as an oil pan of the internal combustion engine. A lubricating fluid, for example oil, may be used as the cooling fluid of the device 10 for cooling and lubricating the pistons 12.

(12) The fluid pump 16 draws in the cooling fluid/lubricating fluid. The fluid pump 16 may be constructed as an oil pump. The fluid pump 16 may be a controllable pump. A fluid flow which is provided by the fluid pump 16 can be directed to the fluid cooler 18 for cooling. The cooled fluid flow can be directed to the fluid filter 20. The cooled and filtered fluid flow is available downstream of the fluid filter 20 for lubricating and cooling components of the internal combustion engine, for example, the piston 12.

(13) The fluid flow is directed to the valve 22; 122. The valve 22; 122 is constructed as a throttle valve for throttling the fluid flow. The fluid flow which is directed to the injection nozzles is adjusted via the valve 22; 122. The valve 22; 122 is provided upstream of the plurality of injection nozzles 24. In detail, the valve 22; 122 is provided upstream of a main cooling fluid duct 26 which branches into a plurality of individual cooling fluid ducts 28. The individual cooling fluid ducts 28 direct the fluid flow from the main cooling fluid duct 26 to the plurality of injection nozzles 24. The valve 22; 122 may be arranged, for example, in a piston cooling gallery of the internal combustion engine.

(14) The injection nozzles 24 act as piston cooling nozzles. The injection nozzles 24 may be provided without any individual valves. The injection nozzles 24 inject the cooling fluid from below towards the pistons 12 so that the pistons 12 are cooled during operation. Finally, the injected cooling fluid arrives back in the fluid reservoir 14. As a result, the device 10 forms a fluid circuit.

(15) FIG. 2 shows two piston cooling paths against an engine speed of an internal combustion engine.

(16) In principle, a cooling requirement of the pistons of an internal combustion engine can be connected to the engine power. For example, it may be necessary to provide per kilowatt of engine power lubricating fluid in a range from 4 to 7 kg/h for cooling the pistons via injection nozzles.

(17) A solid line A shows an exemplary conventional actual piston cooling. A broken line B shows an exemplary desired piston cooling. For the line A, a rigid fluid pump is used and no control takes place. As can be seen, a substantially increased cooling provision for the pistons is provided in a low speed range. In the range between 600 rpm and 1400 rpm, consumers such as a turbocharger or bearings (for example, main bearing and connecting rod bearing of the crankshaft) determine the required fluid pressure. The line B shows that the desired piston cooling power is constant in kilogrammes per kilowatt of engine power against the engine speed.

(18) During a comparison of lines A and B, it is further evident that the conventional piston cooling particularly provides a substantially excessive cooling supply for the piston in the main driving range of a utility vehicle between 1000 rpm and 1400 rpm. An unnecessarily high energy consumption of the fluid pump is associated therewith.

(19) The present disclosure is directed inter alia towards bringing the actual piston cooling towards the desired piston cooling. With reference to FIG. 1, it is proposed in this regard that the valve 22; 122 be arranged in or upstream of the main cooling fluid duct 26. The valve 22; 122 is provided as a central valve for all the injection nozzles 24. As explained in detail with reference to the following embodiments, the valve 22; 122 is provided to adapt the (cooling) fluid flow for the injection nozzles 24 to the actual requirement of the pistons 12. To this end, the valve 22; 122 opens to an increasing extent, for example, with an increasing fluid pressure, so that at higher fluid pressures more fluid is directed to the injection nozzles 24. It is additionally proposed that the valve 22; 122 be constructed so that it produces substantially no pressure loss of the fluid flow flowing through in the completely open state. As a result, in particular a disadvantage of the resiliently loaded non-return ball valve can be overcome which also generate a substantial pressure loss as a result of the construction when fully open in that a valve ball of the non-return valve is positioned centrally in the fluid duct and has to be flowed around by the fluid flow. This increase of pressure loss in the non-return ball valve must be applied by the fluid pump and costs unnecessary drive power. However, the valve 22; 122 is constructed in such a manner that, when the valve 22; 122 is completely open, no pressure loss is brought about by the valve element. Consequently, no unnecessary drive power is necessary to compensate for a pressure loss.

(20) FIGS. 3 and 4 show a first embodiment of the valve 22.

(21) The valve 22 has a fluid duct 30 and a valve element 32.

(22) The fluid duct 30 extends rectilinearly between an inlet opening 34 and an outlet opening 36. As a result, the valve 22 is constructed as a straight-way valve.

(23) The valve element 32 can be displaced into the fluid duct 30 in order to reduce a flow cross-section of the fluid duct 30. Similarly, the valve element 32 can be displaced out of the fluid duct 30 in order to increase a flow cross-section of the fluid duct 30. The valve element 32 acts as a piston. As a result, the valve 22 is constructed as a piston valve.

(24) A displacement of the valve element 32 is brought about by a pressure of the cooling fluid. As a result, the valve element 32 is a valve actuated by an inherent medium. In detail, cooling fluid is directed via a supply duct 38 to a control fluid chamber 40 of the valve 22 from a location upstream of the valve element 32. The cooling fluid directed into the control fluid chamber 40 fills the control fluid chamber 40 and abuts a control face 42 of the valve element 32. With increasing fluid pressure, the valve element 32 can be displaced counter to a resilient force of a resilient element 44 of the valve 22.

(25) In particular, the valve element 32 can be displaced between a position illustrated in FIG. 3 and a position illustrated in FIG. 4. With increasing fluid pressure, the valve element 32 is displaced in a direction towards the position illustrated in FIG. 4. With decreasing fluid pressure, the valve element 32 is displaced in a direction towards the position illustrated in FIG. 3. The valve element 32 is pretensioned in a direction towards the position illustrated in FIG. 3 by the resilient element 44, for example, a helical spring. In detail, the valve element 32 is pushed through an opening 46 in the fluid duct 30 into or out of the fluid duct 30. The form of a region of the opening 46 as illustrated in FIG. 4 is produced in the case of a cylindrical form of the fluid duct 30 and a cylindrical form of the valve element 32 so that the valve element 32 can substantially be displaced relative to the fluid duct 30 in a sealing manner towards the opening 46.

(26) In the position of the valve element 32 illustrated in FIG. 3, a flow cross-section of the fluid duct 30 is at a minimum but greater than zero. As a result, a cooling fluid flow to the injection nozzles 24 (see FIG. 1) is never completely interrupted. In other embodiments, however, it is also possible for the flow cross-section of the fluid duct 30 to be set to zero.

(27) In the position of the valve element 32 illustrated in FIG. 4, a flow cross-section of the fluid duct 30 is at a maximum. In this case, it should be particularly emphasised that the valve element 32 does not influence the flow cross-section of the fluid duct 30 at all. Instead, the valve element 32 is positioned outside the fluid duct 30. At a great fluid pressure, consequently, the valve 22 opens completely and the valve element 32 does not bring about any pressure loss.

(28) Furthermore, the valve 22 has a leakage duct 48 for guiding back leakage fluid. Cooling fluid which has escaped from the fluid duct 30 and the control fluid chamber 40 can be discharged via the leakage duct 48.

(29) In the embodiment illustrated, the valve element 32 in the position illustrated in FIG. 3 cannot close further because the valve element 32 abuts a stop 50 (see FIG. 4). The stop 50 may be an edge of the opening 46.

(30) FIGS. 5 and 6 show a second embodiment of the central valve of FIG. 1 which is designated 122 in this instance for greater distinctiveness.

(31) The valve 122 has a fluid duct 130 and a valve element 132. The valve 122 is again a piston valve and is actuated by an inherent medium.

(32) The fluid duct 130 extends between an inlet opening 134 and an outlet opening 136 at right-angles. As a result, the valve 122 is constructed as a corner valve.

(33) The valve element 132 functions in principle in the manner of the valve element 32 of the valve 22 of FIGS. 3 and 4. The valve element 132 can be displaced between a position illustrated in FIG. 5 and a position illustrated in FIG. 6. Unlike the first embodiment, the valve element 132 has an end face of the valve element 32 as a control face 142, which end face faces in the direction towards the inlet opening 134.

(34) With increasing fluid pressure, the valve element 132 can be pushed in a direction counter to the resilient force of the resilient element 144 through an opening 146 in the fluid duct 130 out of the fluid duct 130. Cooling fluid which has escaped from the fluid duct 130 can be discharged via the leakage duct 148.

(35) The valve 122 can be used, for example, in the form of a plug-in valve for insertion into a blind hole.

(36) The invention is not limited to the above-described preferred embodiments. Instead, a large number of variants and modifications which also make use of the inventive notion and which are therefore included in the protective scope are possible. In particular, the invention also claims protection for the subject-matter and the features of the dependent claims irrespective of the claims referred to. In particular, the features of the independent claim 1 are disclosed independently of each other. In addition, the features of the dependent claims are also disclosed independently of all the features of the independent claim 1 and, for example, independently of the features with respect to the presence and/or the configuration of the fluid duct and/or the valve element of the independent claim 1.

LIST OF REFERENCE NUMERALS

(37) 10 Device for piston cooling 12 Piston 14 Fluid reservoir 16 Fluid pump (fluid source) 18 Fluid cooler 20 Fluid filter 22, 122 Valve 24 Injection nozzle 26 Main cooling fluid duct 28 Individual cooling fluid duct 30, 130 Fluid duct 32, 132 Valve element (piston) 34, 134 Inlet opening 36, 136 Outlet opening 38 Supply duct 40 Control fluid chamber 42, 142 Control face 44, 144 Resilient element 46, 146 Valve element opening 48, 148 Leakage duct 50 Stop