Internal combustion engine

Abstract

The invention relates to an internal combustion engine comprising a combustion engine (10) and a cooling system, which has a coolant pump (40), a main cooler (38), a heating heat exchanger (36), coolant channels (28, 30) in the combustion engine (10), and a control device (20) having an actuator (26) for the closed-loop distribution of a coolant according to at least one local coolant temperature, characterised in that the control device (20) can be connected to a coolant compensation container (106) via a connection in line and, with an actuation of the actuator (26) in one direction, the control device (20): permits a coolant flow through the coolant channels (28, 30) of the combustion engine (10), and through the heating heat exchanger (36), and prevents same through the main cooler (38), and closes the connection line in a first primary position (80); releases the connection line in a second primary position (96); and also permits a coolant flow though the main cooler (38) in a third primary position (126).

Claims

1. A combustion machine having an internal combustion engine and a cooling system for conveying a coolant, the cooling system comprising a coolant pump, a primary cooler, a heating heat exchanger, coolant channels in the internal combustion engine, one or more coolant temperature sensors and a regulator with an actuator, wherein the regulator can be connected to a coolant expansion tank via a connecting line and, when the actuator is actuated in accordance with a temperature of the conveyed coolant measured by the one or more coolant temperature sensors, the regulator switches between: a first main position in which coolant is allowed to flow through the coolant channels of the internal combustion engine as well as through the heating heat exchanger and in which coolant is prevented from flowing through the primary cooler, and the connecting line is closed off; a second main position in which the connecting line is open, and in which coolant is allowed to flow through the coolant channels of the internal combustion engine as well as through the heating heat exchanger, and in which coolant is prevented from flowing through the primary cooler; and a third main position in which coolant is allowed to flow through the primary cooler, and in which coolant is allowed to flow through the connecting line, the coolant channels of the internal combustion engine as well as through the heating heat exchanger; wherein the actuator is configured to switch the regulator to: the first main position after the coolant temperature reaches a first limit value; the second main position after the coolant temperature reaches a second limit value; and the third main position after the coolant temperature reaches a third limit value; and wherein the first limit value and the second limit value are predefined to minimize a loss of thermal energy during a warm-up phase of the internal combustion engine by delaying a time at which an exchange of the coolant to the coolant expansion tank occurs.

2. The combustion machine according to claim 1, wherein the connecting line is a vent line that connects the regulator to a section of the expansion tank that is provided to hold air during operation of the combustion machine.

3. The combustion machine according to claim 1, further comprising a bypass that bypasses the heating heat exchanger, and wherein, when the actuator is actuated, the regulator, when it is in the first main position and in the second main position, prevents coolant from flowing through the bypass, and when it is in a first intermediate position that follows the second main position, additionally allows coolant to flow through the bypass.

4. The combustion machine according to claim 3, wherein, when the regulator is in the third main position, the regulator once again prevents coolant from flowing through the bypass.

5. The combustion machine according to claim 1, wherein the internal combustion engine comprises a cylinder housing and a cylinder head, whereby, when the regulator is in the first main position, the regulator allows coolant to flow through a coolant channel of the cylinder head and it prevents coolant from flowing through a coolant channel of the cylinder housing.

6. The combustion machine according to claim 5, wherein, when the regulator is in a second intermediate position between the second main position and the third main position, the regulator additionally allows coolant to flow through the coolant channel of the cylinder housing.

7. The combustion machine according to claim 1, wherein the regulator comprises a lock valve that is moved by the actuator, whereby the lock valve has a section in which, within a movement range that can be effectuated by means of the actuator, the lock valve is congruent with an outlet of the connecting line, whereby a portion of this section is formed by a through opening that is fluidically connected to a volume of the regulator that is provided to convey coolant.

8. The combustion machine according to claim 7, wherein the outlet is formed by a tubular connecting piece whose one end is mounted, either directly or via an interconnected sealing element, in such a way that it slides on the lock valve when the lock valve is moved by the actuator.

9. The combustion machine according to claim 8, wherein the sealing element is configured as a pipe plug that is inserted into the end of the connecting piece.

10. A method for filling the cooling system of the combustion machine according to claim 1 with coolant, wherein the regulator is switched to the third main position in order to fill the cooling system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The combustion machine according to the invention will be explained in greater detail below making reference to the embodiments shown in the drawings. The drawings show the following:

(2) FIG. 1: a combustion machine according to the invention, schematically in a block diagram;

(3) FIG. 2: a regulator for a combustion machine according to the invention, in an exploded view;

(4) FIG. 3: the regulator in a side view;

(5) FIG. 4: the regulator with the housing only partially depicted;

(6) FIG. 5: an actuator and the lock valves of the regulator, which are actuated directly or indirectly by the actuator, in an isolated view;

(7) FIG. 6: a section of the first lock valve and of a connecting piece that interacts with it; and

(8) FIG. 7: the flow of coolant through the individual components of a combustion machine according to the invention as shown in FIG. 1, as a function of the various positions of the regulator.

DETAILED DESCRIPTION OF THE INVENTION

(9) FIG. 1 schematically shows a combustion machine according to the invention. It comprises an internal combustion engine 10 that can be configured, for instance, as a reciprocating-piston internal combustion engine based on the Otto or Diesel principle and that comprises a cylinder housing 12 as well as a cylinder head 14. Moreover, the combustion machine also has a primary cooling system and a secondary cooling system. The primary cooling system serves primarily to cool the internal combustion engine 10, whereas the secondary cooling system serves to cool an exhaust gas turbocharger 16 and an intercooler 18 of the charged internal combustion engine 10. Here, the temperature of the coolant during regular operation of the combustion machine can be considerably higher in the primary cooling system than in the secondary cooling system, at least in certain sections, so that the former can also be referred to as a high-temperature cooling system and the latter as a low-temperature cooling system.

(10) The primary cooling system also comprises a regulator 20 with a first lock valve 22, a second lock valve 24 and an actuator 26. The first lock valve 22 can be moved by means of the actuator 26, whereas, in a section of the total possible movement of the first lock valve 22, the second lock valve 24 would be moved along by the first lock valve 22. The primary cooling system also comprises coolant channels 28, 30 of the cylinder housing 12 and of the cylinder head 14, whereby, for cooling purposes, the coolant channels 30 of the cylinder head 14 also pass through a coolant channel 32 of an exhaust manifold that is integrated into the cylinder head 14. Furthermore, the primary cooling system comprises a motor oil cooler 34 through which coolant can flow in parallel to the coolant channels 30 of the cylinder head 14, and it also comprises a heating heat exchanger 36, a primary cooler 38 as well as a coolant pump 40. Here, the individual components of the primary cooling system are fluidically connected via coolant lines. Finally, the primary cooling system also comprises a bypass 42 that is integrated into the regulator 20 and that, while bypassing the heating heat exchanger 36 as well as the primary cooler 38, serves to connect a first inlet 44 of the regulator 20 to a first inlet 46 of the coolant pump 40.

(11) FIGS. 2 to 6 show a possible structural configuration of the regulator 20 of the combustion machine according to FIG. 1. In this regulator 20, the lock valves 22, 24 are configured in the form of rotary valves that, depending on their particular direction of rotation, open or close inlets and outlets for the coolant that is flowing through the regulator 20 as well as for a vent line.

(12) Accordingly, the regulator 20 comprises a housing 48 into which an impeller 50 of a coolant pump 40 configured as an impeller pump is integrated so as to rotate. The rotation of the impeller 50 and thus the pumping of coolant in the primary cooling system are effectuated, for example, by the internal combustion engine 10, for which purpose a crankshaft (not shown here) of the internal combustion engine 10 is connected via a belt drive to a shaft 52 for the impeller 50. The only part of the belt drive that is shown in FIGS. 2 and 3 is a belt wheel 54 that is part of the coolant pump 40 and that is connected to the shaft 52.

(13) In order for the coolant to be pumped, coolant is fed to the impeller 50 via the first inlet 46 and/or via a second inlet 56 of the coolant pump 40. The first inlet 46 is connected via a coolant line, on the one hand, to an outlet 58 of the primary cooler 38 and, on the other hand, to the bypass 42. Here, it is provided for the coolant line that forms the bypass 42 to be integrated as a channel into the housing 48 of the regulator 20. The second inlet 56 of the coolant pump 40 is connected via a coolant line to an outlet 60 of the heating heat exchanger 36.

(14) Owing to the rotation of the impeller 50, the coolant is conveyed to a first outlet 64 of the regulator 20 through a coolant channel 62 formed inside the housing 48. When the regulator 20 is in a zero position 66, this first outlet 64 is closed by means of a closure element 68 of the second lock valve 24, which is in a closed position. This completely prevents the coolant from circulating through the cooling system. When the regulator 20 is in the zero position 66, the first lock valve 22 is in an orientation in which a second outlet 70 of the regulator 20, which is connected via a coolant line to an inlet 72 of the heating heat exchanger 36, is closed by means of a first closure element 74 of the first lock valve 22. The zero position 66 of the regulator 20 is provided for a short period of time after a cold start of the combustion machine. A cold start of the combustion machine is characterized in that the components of the combustion machine, and especially also the coolant of the primary cooling system, exhibit temperatures that essentially match the ambient temperature but that are at least below a defined limit temperature.

(15) After a cold start of the combustion machine and after a defined first limit value has been reached for a local coolant temperature—which is measured by means of a first coolant temperature sensor 78 integrated into the coolant channel 30 in the vicinity of an outlet 76 of the cylinder head 14—the regulator 20 is switched from the zero position 66 to a first main position 80 by means of the actuator 26. For this purpose, the actuator 26 is actuated by a motor control unit 82 of the combustion machine to which the measurement signal of the first coolant temperature sensor 78 is transmitted. In this context, it can be provided that the regulator 20 is switched from the zero position 66 to the first main position 80, either stepwise or continuously, as a function of the local coolant temperature, which is measured by means of the first coolant temperature sensor 78, said switching procedure being effectuated by a rotation—associated with a rise in temperature—of the first lock valve 22 and of the second lock valve 24 that is still coupled to the first lock valve 22 so as to rotate (see FIG. 7). In this process, the lock valves 22, 24 can also be rotated back in the interim. The first lock valve 22 is rotated by means of the actuator 26, which is connected to the first lock valve 22 via a shaft 84.

(16) When the regulator 20 is in the first main position 80, the second lock valve 24 is in an open position in which the first outlet 64 of the regulator 20 is no longer closed off by the closure element 68, but rather, it is essentially completely open. At the same time, the first lock valve 22 is in an orientation in which its first closure element 74 no longer closes the second outlet 70 but rather opens it essentially completely. At the same time, a second closure element 86 of the first lock valve 22 closes a second inlet 90 of the regulator 20 that is connected to an outlet 88 of the cylinder housing 12, and it also closes a third outlet 94 of the regulator 20 that is connected to an inlet 92 of the primary cooler 38 via a coolant line as well as the bypass 42 that is integrated into the regulator 20. Therefore, when the regulator 20 is in the first main position 80, the conveying of the coolant effectuated by the coolant pump 40 only takes place in a small cooling circuit comprising the coolant pump 40, the regulator 20, the cylinder head 14 and the heating heat exchanger 36.

(17) After a defined second limit value has been reached for the local coolant temperature in the cylinder head 14, which is measured by means of the first coolant temperature sensor 78, the regulator 20 is switched from the first main position 80 to a second main position 96. In this process, the first lock valve 22 is rotated into an orientation in which a fourth outlet 98 of the regulator 20 is increasingly opened by a third closure element 100 of the first lock valve 22, as a result of which a first vent line 102 (with the integrated non-return valve 104) that connects the fourth outlet 98 of the regulator 20 to an expansion tank 106 (in a section of the expansion tank 106 located at the top) is increasingly opened accordingly. Starting after the second main position 96 of the regulator 20, the regulator 20 can be vented via the first vent line 102 that, with an at least slight overflow of coolant, can also be connected between the regulator 20 and the expansion tank 106 via a first overflow line 108 that branches off from a lower section of the expansion tank 106. Owing to the relatively late activation of the expansion tank 106 (after a cold start of the combustion machine), heat losses in the expansion tank 106, which would cause a delay in reaching an operating temperature range for the cylinder head 14 as well as a delay in the heating effect of the heating heat exchanger 36, can be kept to a minimum.

(18) FIG. 6 shows a tubular connecting piece 112 that is integrated into the housing 48 (not shown in FIG. 6) of the regulator 20 and that is provided for purposes of connection to the first vent line 102. One end of the connecting piece 112 is movably (by rotating the first lock valve 22) mounted on a section of the first lock valve 22 that forms the third closure element 100, whereby, in the second main position 96, this end of the connecting piece 112 is arranged to be congruent with a slit-shaped through opening of the first lock valve 22, as a result of which the connecting piece 112 is then fluidically connected to a volume of the regulator that conveys coolant. In this manner, the first vent line 102 is opened. A sealing element 114 in the form of a pipe plug (that is to say, a tubular plug) made of an elastic material ensures a sufficient sealing of the connecting piece 112 vis-à-vis the third closure element 100 when the first vent line 102 is not supposed to be opened. In this context, the material of the sealing element 114 is preferably selected in such a way as to ensure low-friction sliding on the appertaining section of the first lock valve 22.

(19) After a defined third limit value has been reached for the local coolant temperature in the cylinder head 14, which is measured by means of the first coolant temperature sensor 78, the regulator 20 is switched from the second main position 96 to a first intermediate position 110. In this process, the first lock valve 22 is rotated into an orientation in which the bypass 42 is increasingly opened by the second closure element 86, as a result of which the bypass 42 is integrated into the small cooling circuit in parallel to the heating heat exchanger 36. Here, the second inlet 90 and the third outlet 94 of the regulator 20 continue to be kept closed by the first lock valve 22. During this movement of the first lock valve 22, the second lock valve 24 remains in its open position since it is no longer coupled to the first lock valve 22 so as to rotate. Due to the integration of the bypass 42 into the (small) cooling circuit in the first intermediate position 110 of the regulator 20, the entire volumetric flow of the coolant that is being conveyed in the primary cooling system can be increased in order to achieve a correspondingly high cooling capacity for the cylinder head 14 and for the motor oil cooler 34.

(20) The rotational coupling of the first lock valve 22 to the second lock valve 24, which is only done during certain phases, is effectuated by segment teeth 116 that are only intermeshed when the first lock valve 22 is rotated (back and forth) between the zero position 66 and the first main position 80. The second lock valve 24 is secured in its open position with a positive fit by the first lock valve 22 in that a ring segment 118 that adjoins the segment teeth 116 of the first lock valve 22 engages with a concave depression 120 that adjoins the segment teeth 116 of the second lock valve 24, and said ring segment 118 is moved relatively so as to slide in this depression 120 as the first lock valve 22 rotates, as a result of which the ring segment 118 is held so as to be non-rotatably affixed altogether.

(21) After a defined fourth limit value has been reached for the local coolant temperature in the cylinder head 14, which is measured by means of the first coolant temperature sensor 78, and/or after a defined first limit value has been reached for a local coolant temperature in the cylinder housing 12, which is measured by means of a second coolant temperature sensor 122 situated in the vicinity of the outlet 88 of the cylinder housing 12, the regulator 20 is switched from the first intermediate position 110 to a second intermediate position 124. In this process, the first lock valve 22 is rotated into an orientation in which the second closure element 86 also (increasingly) opens the second inlet 90 of the regulator 20 (see FIG. 7). Consequently, only the third outlet 94 of the regulator 20 is still kept closed, thus preventing coolant from flowing through the primary cooler 38. Therefore, in the second intermediate position 124, it is provided that the coolant also flows through the cylinder housing 12.

(22) After a defined fifth limit value has been reached for the local coolant temperature in the cylinder head 14, which is measured by means of the first coolant temperature sensor 78, and/or after a defined second limit value has been reached for the local coolant temperature in the cylinder housing 12, which is measured by means of the second coolant temperature sensor 122, and/or as a function of an engine characteristic map of the combustion machine stored in the motor control unit 82, the regulator 20 is switched from the second intermediate position 124 to a third main position 126. In this process, the third outlet 94 of the regulator 20 is (increasingly) opened and consequently, the primary cooler 38 is incorporated into what is then a large cooling circuit, while at the same time, the bypass 42 that is integrated into the regulator 20 is increasingly closed once again by the second closure element 86 of the first lock valve 22 (see FIG. 7). This ensures that, except for relatively small portions of the coolant that are being conveyed through the heating heat exchanger 36 and through the expansion tank 106, the coolant is fed completely via the primary cooler 38, where it is cooled by means of heat transfer to the ambient air.

(23) A second vent line 128, which branches off from the primary cooler 38 and into which a non-return valve 130 is likewise integrated, also opens up into the upper section of the expansion tank. This advantageously allows a venting of the primary cooler 38, especially in the third main position 126 of the regulator 20.

(24) The third main position 126 of the regulator 20 is also intended for those cases in which the combustion machine is not in operation. This is meant, on the one hand, to implement a failsafe function by means of which—in case of a defect of the cooling system that might been caused, for example, by weasel bites when a motor vehicle powered by a combustion machine was not in operation—it is also possible to continue to ensure the functionality of the primary cooling system, which, although functionally limited, nevertheless continues to provide an adequate (since it is the maximum possible) cooling capacity. Moreover, when the combustion machine is not in operation, the third main position 126 of the regulator 20 allows the primary cooling system to be filled and emptied within the scope of assembly or maintenance work, since the coolant that has been filled via the expansion tank 106 and fed into the components of the primary cooling system via the first overflow line 108 can be distributed unhindered in the primary cooling system and, in this process, air contained in the primary cooling system can escape via the first vent line 102, via the second vent line 128 and subsequently via the expansion tank 106.

(25) The secondary cooling system of the combustion machine according to FIG. 1 comprises a cooling circuit into which the two components that have to be provided with cooling, namely, the exhaust gas turbocharger 16 and the intercooler 18, are integrated in parallel. Coolant is conveyed in this cooling circuit by means of an auxiliary coolant pump 132 that can especially be powered by an electric motor. A separate (low-temperature) cooler 134 serves to re-cool the coolant of the secondary cooling system.

(26) The expansion tank 106 of the combustion machine is also integrated into the secondary cooling system, for which purpose a third vent line 136 is provided that is arranged in a section that—downstream from the exhaust gas turbocharger 16 and downstream from the intercooler 18 as well as upstream from the (low-temperature) cooler 134, as seen in the flow direction of the coolant—branches off from the cooling circuit of the secondary cooling system and that—incorporating a throttle element 138 as well as a non-return valve 140—is, in turn, connected to the upper section of the expansion tank 106. Moreover, a second overflow line 142 is provided by means of which the lower section of the expansion tank 106 that holds coolant is connected to a section of the cooling circuit of the secondary cooling system arranged between the (low-temperature) cooler 134 and the auxiliary coolant pump 132.

(27) Below, the functionalities of the primary cooling system that can be achieved by the various positions of the regulator 20 will be explained, once again in summary, making reference to FIG. 7.

(28) When the combustion machine is not in operation (both when the coolant is still warm as well as when the coolant has cooled off completely), the regulator 20 is in the third main position 126. In this manner, the failsafe function is implemented if it is not possible to switch the regulator 20 due to a defect after the combustion machine has been started. Moreover, this makes it possible to fill and vent the primary cooling system within the scope of assembly or maintenance work, without the combustion machine having to be in operation.

(29) In order to attain a cold start of the combustion machine, the regulator 20 is switched to the zero position 66. In this process, the zero position 66 is retained during the first warm-up phase 144. As a result, the coolant is prevented from circulating inside the primary cooling system so as to achieve a relatively fast warm-up of the coolant that is present in the internal combustion engine 10, especially in the cylinder head 14.

(30) Relatively soon after the cold start of the combustion machine, the regulator 20 starts to be switched from the zero position 66 to the first main position 80, as a result of which the cylinder head 14 and the motor oil in the motor oil cooler 34 are increasingly cooled and the heating functionality is achieved by means of the heating heat exchanger 36.

(31) During a third warm-up phase 148, the regulator is increasingly switched from the first main position 80 to the second main position 96, as a result of which venting of the regulator 20 can be achieved via the first vent line 102 and via the expansion tank 106. The fact that the venting only starts at a relatively late point in time reduces heat losses during the first two warm-up phases 144, 146.

(32) During a fourth warm-up phase 150, the regulator 20 is increasingly switched from the second main position 96 to the first intermediate position 110. By means of the bypass 42, which is then increasingly integrated into the small cooling circuit, an increase in the volumetric flow rate of the coolant in the small cooling circuit can be achieved and consequently, the formation of so-called hot spots, especially in the cylinder head 14 of the internal combustion engine 10, can be avoided.

(33) During a fifth warm-up phase 152, the regulator 20 is increasingly switched from the first intermediate position 110 to the second intermediate position 124, as a result of which the cylinder housing 12 is also increasingly cooled. The volumetric flow rate of the coolant that is being conveyed via the bypass 42 can be further increased, at least at the beginning of the fifth warm-up phase 152.

(34) Once the coolant of the primary cooling system has reached an operating temperature range (normal operating phase 154), the regulator 20 is switched between the second intermediate position 124 and the third main position 126 by means of the motor control unit 82 as a function of an engine characteristic map of the internal combustion engine. In this context, due to an ever-greater reduction of the volumetric flow rate of the coolant that is being conveyed via the bypass 42 and due to a concurrent increase of the volumetric flow rate of the coolant that is being conveyed via the primary cooler 38, it is possible for the components of the primary cooling system to be cooled on an as-needed basis by means of a defined setting of any desired intermediate positions between the second intermediate position 124 and the third main position 126.

(35) When the combustion machine is switched off, that is to say, when it has been changed from an operational state to a non-operational state, it can be provided that the regulator 20 is switched, first beyond the third main position 126 that constitutes an upper, electrically implemented stop (OEA) during the operation of the regulator 20, then briefly to an upper (mechanical) end stop (OMA), then to the zero position 66 that constitutes a lower, electrically implemented stop (UEA) during the operation of the regulator 20, and beyond that, briefly to a lower (mechanical) end stop (UMA), and subsequently briefly once again to the upper end stop (OMA), in order to carry out an end stop diagnosis. This can be relevant for the most exact possible switching of the regulator 20 to the various positions and intermediate positions during the operation of the combustion machine. After this end stop diagnosis, the regulator 20 can then be switched to the third main position 126 (OEA) that is intended when the combustion machine is not in operation. The largely unhindered circulation of the still-warm coolant in the primary cooling system that is achieved in the third main position 126 then also makes it possible to utilize the thermal energy stored in the coolant, for example, for a re-heating function of the heating heat exchanger 36.

LIST OF REFERENCE NUMERALS

(36) 10 internal combustion engine 12 cylinder housing 14 cylinder head 16 exhaust gas turbocharger 18 intercooler 20 regulator 22 first lock valve 24 second lock valve 26 actuator 28 coolant channel of the cylinder housing 30 coolant channel of the cylinder head 32 coolant channel of the exhaust manifold 34 motor oil cooler 36 heating heat exchanger 38 primary cooler 40 coolant pump of the primary cooling system 42 bypass 44 first inlet of the regulator 46 first inlet of the coolant pump 48 housing 50 impeller 52 shaft 54 belt wheel 56 second inlet of the coolant pump 58 outlet of the primary cooler 60 outlet of the heating heat exchanger 62 coolant channel 64 first outlet of the regulator 66 zero position of the regulator 68 closure element of the second lock valve 70 second outlet of the regulator 72 inlet of the heating heat exchanger 74 first closure element of the first lock valve 76 outlet of the cylinder head 78 first coolant temperature sensor 80 first main position of the regulator 82 motor control unit 84 shaft 86 second closure element of the first lock valve 88 outlet of the cylinder housing 90 second inlet of the regulator 92 inlet of the primary cooler 94 third outlet of the regulator 96 second main position of the regulator 98 fourth outlet of the regulator 100 third closure element of the first lock valve 102 first vent line 104 non-return valve of the first vent line 106 expansion tank 108 first overflow line 110 first intermediate position of the regulator 112 connecting piece 114 sealing element 116 segment teeth 118 ring segment 120 depression 122 second coolant temperature sensor 124 second intermediate position of the regulator 126 third main position of the regulator 128 second vent line 130 non-return valve of the second vent line 132 auxiliary coolant pump 134 (low-temperature) cooler 136 third vent line 138 throttle element 140 non-return valve of the third vent line 142 second overflow line 144 first warm-up phase 146 second warm-up phase 148 third warm-up phase 150 fourth warm-up phase 152 fifth warm-up phase 154 normal operating phase