Cooling circuit and method for operating a cooling circuit

Abstract

The invention relates to a cooling circuit (10), in particular for a drive arrangement of a motor vehicle, having the features of claim (1), and to a method for operating such a cooling circuit (10).

Description

[0001] Description

[0002] title

[0003] Cooling circuit and method for operating a cooling circuit

[0004] State of the art

[0005] The invention relates to a cooling circuit, in particular for a drive arrangement of a motor vehicle, with features of claim 1 and a method for operating such a cooling circuit.

[0006] Electromagnetic on / off valves typically have two states: closed or open. Depending on the valve's design, each state can be either normally open or normally closed. To move the valve from the first state to the second (closed or open), a solenoid coil must be energized. Energizing the solenoid coil is also usually necessary to maintain the second state, resulting in a constant power consumption. To return the valve to the first state, the energizing of the solenoid coil is stopped.

[0007] The disadvantage is that energizing the solenoid coil to move the valve into the second state and maintaining the second state results in a constant power consumption and associated energy consumption.

[0008] Disclosure of the invention

[0009] According to the invention, a cooling circuit in which a coolant is or can be circulated is proposed. The cooling circuit can be set up for or form a component of a motor vehicle's drive system. The cooling circuit includes a coolant pump for circulating the coolant within the circuit. The coolant pump is configured to circulate the coolant at a first pressure. The coolant pump is also configured to circulate the coolant at a second pressure. The second pressure can be lower than the first pressure. The cooling circuit includes a valve for interrupting and / or releasing the coolant flow. The valve is configured to be switched from a closed position to an open position by a brief, in particular pulsed, reduction of the pressure applied to the valve.

[0010] This allows the valve to be moved to the closed position using simple means and, in particular, without electricity.

[0011] In this context, "applying pressure" or "applied pressure" refers to a (hydrostatic) pressure of the coolant acting on the valve and, in particular, on an inlet of the valve.

[0012] According to a further development of the cooling circuit, the valve can be designed as an electromagnetic valve. The valve can include a coil. The valve can be configured to be moved into the closed position by a brief, particularly pulsed, energization of the coil. The valve can be configured to be held in the closed position, particularly exclusively, by applying or maintaining the initial pressure. In other words, the valve can be held in the closed position by the hydrostatic pressure of the coolant, which acts, for example, on a valve disc of the valve. In particular, the coil is not energized while the valve is held in the closed position.

[0013] This allows the valve to be moved into the closed position and kept in the closed position using simple means and only by a short, especially pulsed, current flow to the coil.

[0014] According to a further development of the cooling circuit, the valve can include a spring. The valve can be pre-tensioned into the open position by means of the spring. This allows the valve to be moved into the open position and held in the open position using simple means, especially when de-energized.

[0015] According to a further development of the cooling circuit, the valve can comprise an armature and a piston. The armature can be movably arranged within the coil. The armature can be configured to be moved by magnetic force generated, or capable of being generated, by the coil. The piston can be arranged within the valve. The piston can be configured to be moved, in particular driven, by the armature. The valve can comprise a valve disc. The valve disc can be movably arranged in a valve seat of the valve between a first position and a second position. The valve disc can be arranged on the piston.

[0016] This allows the movement of the valve disc to be implemented using simple means.

[0017] According to a further development of the cooling circuit, the valve can comprise an inlet and an outlet. The valve can be configured such that, in the first position, the valve disc fluidically couples the inlet and outlet of the valve, so that the valve is in the open position. In other words, when the valve disc is in the first position, the valve is in the open position. Alternatively or additionally, the valve can be configured such that, in the second position, the valve disc fluidically decouples the inlet and outlet of the valve, so that the valve is in the closed position. In other words, when the valve disc is in the second position, the valve is in the closed position.

[0018] This allows the valve to be switched between open and closed positions using simple means.

[0019] In this context, fluidic coupling means that a fluid (e.g.

[0020] Fluid decoupling means that a fluid (e.g., coolant) can flow between two fluidically coupled elements (e.g., the inlet and outlet of the valve). Conversely, fluidic decoupling means that a fluid (e.g., coolant) cannot flow between two fluidically decoupled elements (e.g., the inlet and outlet of the valve).

[0021] According to a further development of the cooling circuit, the initial pressure can range from 0.5 to 3.0 bar. 3.0 bar can be the maximum delivery pressure of the coolant pump.

[0022] This allows the coolant to be pumped within the cooling circuit using simple means and with a sufficiently high pressure (delivery pressure).

[0023] According to a further development of the cooling circuit, the second pressure can be in the range of 0.0 to 0.5 bar. In particular, the second pressure can be lower than the first pressure. A pressure of 0.0 bar can be achieved, in particular, by switching off the coolant pump.

[0024] By pumping the coolant at the second pressure (and / or switching off the coolant pump), the first pressure can be reduced using simple means.

[0025] According to the invention, a method for operating a cooling circuit as described above is proposed. The method comprises the following step:

[0026] Moving the valve from the closed position to the open position by means of a brief, especially pulse-like, reduction of the pressure applied to the valve, in particular by pumping the coolant at the second pressure and / or switching off the coolant pump.

[0027] Regarding the advantages achievable with this method, reference is made to the relevant explanations concerning the cooling circuit. The measures described in connection with the cooling circuit and / or those explained below can be used to further develop the method.

[0028] According to a further development of the method, the procedure can include the step: transferring the valve from the open position to the closed position by means of a brief, in particular pulsed, current flowing through the coil of the valve.

[0029] This allows the valve to be moved into the closed position using simple means and only by briefly, especially pulsed, current flowing through the coil.

[0030] According to a further development of the procedure, the procedure can include the following step:

[0031] Holding the valve in the closed position by applying and / or maintaining initial pressure on the valve.

[0032] This allows the valve to be kept in the closed position using simple means and without energizing the coil.

[0033] The following are an explanation of embodiments of the invention with reference to the accompanying drawings. Each drawing schematically shows:

[0034] Figure 1 shows a section of a cooling circuit,

[0035] Figure 2 shows a sectional view of a valve and a state diagram of the cooling circuit according to Figure 1 in a first state,

[0036] Figure 3 shows a sectional view of the valve and the state diagram of the cooling circuit according to Figure 1 in a second state and

[0037] Figure 4 shows a sectional view of the valve and the state diagram of the cooling circuit according to Figure 1 in a third state.

[0038] In the following description and in the figures, corresponding components and elements are designated by the same reference numerals. For clarity, not all reference numerals are shown in every figure. Figure 1 schematically shows a section of a cooling circuit 10. A coolant is circulated, or can be circulated, in the cooling circuit 10. The cooling circuit 10 can be configured for a drive system of a motor vehicle or form a component thereof.

[0039] Cooling circuit 10 includes a coolant pump 12 for circulating the coolant within the cooling circuit 10. The coolant pump 12 is configured to circulate the coolant at a first pressure. The coolant pump 12 is also configured to circulate the coolant at a second pressure. The second pressure may be lower than the first pressure.

[0040] The initial pressure can range from 0.5 to 3.0 bar. 3.0 bar can correspond to the maximum delivery pressure of the coolant pump 12.

[0041] The second pressure can be in a range of 0.0 to 0.5 bar. The second pressure can be achieved, in particular, by reducing the first pressure and / or switching off the coolant pump 12.

[0042] The cooling circuit includes a valve 14 for interrupting and / or releasing the coolant flow. The valve 14 is designed to be moved from a closed position 16 to an open position 18 by a brief, particularly pulsed, reduction of the pressure applied to the valve 14. This reduction of the pressure applied to the valve 14 can be achieved by pumping the coolant at the second pressure and / or by switching off the coolant pump 12.

[0043] Figures 2 to 4 each schematically show a sectional view of valve 14 and a state diagram 40 of the cooling circuit 10 according to Figure 1 in various states. In Figures 2 to 4, valve 14 is shown schematically in sectional view at the top.

[0044] The valve 14 can be designed as an electromagnetic valve with a coil 20. The valve 14 can be configured to be moved into the closed position 16 by a brief, in particular pulsed, energization of the coil 20. The valve 14 can be configured to be held in the closed position 16, in particular exclusively, by applying or maintaining the initial pressure.

[0045] The valve 14 can include a spring 22. The valve 14 can be biased into the open position 18 by means of the spring 22.

[0046] The valve 14 can comprise an armature 24, a piston 26, and a valve disc 28. The armature 24 can be movably arranged within the coil 20. The armature 24 can be configured to be moved by the magnetic force generated or capable of being generated by the coil 20. The piston 26 can be arranged within the valve 14. The piston 26 can be configured to be moved (or driven) by the armature 24. The valve disc 28 can be movably arranged in a valve seat 30 of the valve 14 between a first position 32 and a second position 34. The valve disc 28 can be arranged on the piston 26. The valve disc 28 can be biased into the first position 32 by the spring 22.

[0047] The valve 14 can comprise an inlet 36 and an outlet 38. The valve 14 can be configured such that, in the first position 32, the valve disc 28 fluidically couples the inlet 36 and the outlet 38, so that the valve 14 is in the open position 18. Alternatively or additionally, the valve 14 can be configured such that, in the second position 34, the valve disc 28 fluidically decouples the inlet 36 and the outlet 38, so that the valve 14 is in the closed position 16.

[0048] Figures 2 to 4 below schematically depict the state diagram 40 of the cooling circuit 10. The state diagram 40 shows, from bottom to top:

[0049] A coolant flow 42 through the valve 14 (from the inlet 36 to the outlet 38), a pressure curve 44 or coolant flow through the coolant pump 12 and a current curve 46 or current flow to the coil 20 of the valve 14.

[0050] In Figure 2, the valve 14 is shown in the open position with no current flowing (see current curve 46). The valve 14 is biased into the open position and held there by the spring force of spring 22, which acts on the valve disc 28. The spring force exerted on the valve disc 28 by spring 22 is indicated in Figures 2 to 4 by a left-pointing arrow. The coolant is conveyed through the valve 14 at the initial pressure. Due to the open position, i.e., the open valve 14, the coolant is conveyed from the inlet 36 to the outlet 38. The coolant flow 42 through the valve 14, the pressure curve 44 through the coolant pump 12, and the current curve 46 of the coil 20 are represented at the time of the depicted state by a vertical bar through the respective curves 42, 44, and 46.

[0051] In Figure 3, the coil 20 of the valve 14 is briefly or pulsedly energized. The coil 20 generates a magnetic field and a resulting magnetic force, which moves the armature 24, which drives the piston 26 on which the valve disc 28 is mounted, to the right in Figure 3. This is indicated in Figure 3 by a right-pointing arrow. This moves the valve disc 28 against the spring force of the spring 22 from the first position 32 to the second position 34, thus bringing the valve 14 into the closed position 16. The valve 14 is thus closed and blocks the coolant flow from the inlet 36 to the outlet 38. The valve disc 28 is held in the closed position 16 due to the pressure applied at the inlet 36 of the valve 14, which exerts a (hydrostatic) force on the valve disc 28 to the right in Figure 3, even if the magnetic force generated by the coil 20 is absent (see current flow 46).The coolant flow 42 through the valve 14, the pressure curve 44 through the coolant pump 12 and the current curve 46 of the coil 20 are represented at the time of the depicted state by means of a vertical bar through the respective curves 42, 44, 46.

[0052] In Figure 4, the coolant pump 12 is controlled such that it briefly, and in particular in pulses, delivers the coolant at the second pressure. The second pressure is lower than the first pressure (see in particular the pressure curve 44 through the coolant pump 12). Alternatively or additionally, the coolant pump 12 can also be briefly switched off, and in particular in pulses (in this case, the second pressure can be 0.0 bar). This reduces the pressure applied to the valve 14, or rather to its inlet 36, below the first pressure, so that the valve disc 28 is returned to the open position 18 by means of the spring 22, and the valve 14 opens again. After the subsequent delivery of the coolant at the first pressure, the valve disc 28 is held in the first position 32, and thus the valve 14 is held in the open position 18, by the spring force of the spring 22.The coolant flow 42 through the valve 14, the pressure curve 44 through the coolant pump 12 and the current curve 46 of the coil 20 are represented at the time of the depicted state by means of a vertical bar through the respective curves 42, 44, 46.

[0053] The first pressure can be chosen such that the (hydrostatic) force acting on the valve disc 28 due to the first pressure is greater than the spring force of the spring 22. Similarly, the second pressure can be chosen such that the (hydrostatic) force acting on the valve disc 28 due to the second pressure is less than the spring force of the spring 22.

[0054] The re-closing of the valve 14 or the transfer of the valve 14 to the closed position 16 can again be implemented by a brief, in particular pulsed, current flow to the coil 20 (see Figure 2 and the corresponding descriptions above).

[0055] The following describes a method for operating a cooling circuit 10 according to the above descriptions, with reference to Figures 1 to 4. The cooling circuit 10 can be the one shown in Figure 1. The method comprises the following step:

[0056] Moving the valve 14 from the closed position 16 to the open position 18 by means of a brief, in particular pulsed, reduction of the pressure applied to the valve 14. The reduction of the pressure applied to the valve 14 can be achieved by pumping the coolant at the second pressure and / or by switching off the coolant pump 12.

[0057] The procedure may include the following steps:

[0058] Moving the valve 14 from the open position 18 to the closed position 16 by means of a brief, in particular pulsed, current flowing through the coil 20 of the valve 14. The method may include the following step:

[0059] Holding the valve 14 in the closed position 16 by applying and / or holding the first pressure on the valve 14 or its inlet 36.

[0060] The procedure may include the following steps:

[0061] Holding the valve 14 in the open position 18, in particular exclusively, by means of spring force of the spring 22.

Claims

Claims 1. Cooling circuit (10), in particular for a drive arrangement of a motor vehicle in which a coolant is or can be conveyed, comprising: a coolant pump (12) for pumping the coolant within the cooling circuit (10), wherein the coolant pump (12) is configured to pump the coolant at a first pressure and / or a second pressure, a valve (14) for interrupting and / or releasing a coolant flow, wherein the valve (14) is configured to be transferred from a closed position (16) to an open position (18) by a brief, in particular pulse-like, reduction of the pressure applied to the valve (14).

2. Cooling circuit (10) according to claim 1, characterized in that the valve (14) is designed and configured as an electromagnetic valve with a coil (20) to be brought into the closed position (16) by a short-term, in particular pulse-like, current flowing to the coil (20) and, in particular, exclusively, to be held in the closed position (16) by applying the first pressure.

3. Cooling circuit (10) according to claim 1 or 2, characterized in that the valve (14) comprises a spring (22), wherein the valve (14) is biased into the open position (18) by means of the spring (22).

4. Cooling circuit (10) according to one of the preceding claims, characterized in that the valve (14) comprises: an armature (24), wherein the armature (24) is arranged and configured within the coil (20) to be moved by the magnetic force which is or can be generated by the coil (20), a piston (26) which is arranged in the valve (14) and is designed to be moved by means of the armature (24), a valve disc (28) which is movably arranged in a valve seat (30) of the valve (14) between a first position (32) and a second position (34), wherein the valve disc (28) is arranged on the piston (26).

5. Cooling circuit (10) according to claim 4, characterized in that the valve (14) comprises an inlet (36) and an outlet (38) and is configured such that The valve disc (28) in the first position (32) fluidically couples the inlet (36) and the outlet (38) to each other, so that the valve (14) is arranged in the open position (18) and / or The valve disc (28) in the second position (34) fluidically decouples the inlet (36) and the outlet (38) from each other, so that the valve (14) is arranged in the closed position (16).

6. Cooling circuit (10) according to one of the preceding claims, characterized in that the first pressure is in a range of 0.5 to 3.0 bar.

7. Cooling circuit (10) according to one of the preceding claims, characterized in that the second pressure is in a range of 0.0 to 0.5 bar.

8. Method for operating a cooling circuit (10) according to any one of the preceding claims, comprising the step: Transferring the valve (14) from the closed position (16) to the open position (18) by means of a brief, in particular pulse-like, reduction of the pressure applied to the valve (14), in particular by pumping the coolant at the second pressure and / or switching off the coolant pump (12).

9. Method according to claim 8, characterized by the step: Moving the valve (14) from the open position (18) to the closed position (16) by means of a brief, in particular pulsed, current flowing to the coil (20) of the valve (14).

10. Method according to claim 8 or 9, characterized by the step of: holding the valve (14) in the closed position (16) by applying and / or holding the first pressure on the valve (14).

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