CN115704427A - Hydraulic control device, double clutch having such a control device, and method for operating such a control device - Google Patents

Abstract

The invention relates to a hydraulic control device (2) for actuating a double clutch, comprising: a hydraulically actuatable first actuator (4) for a first clutch of the dual clutch; a second hydraulically actuatable actuator (6) for a second clutch of the dual clutch; and a separate switching valve (12) having an input (14), a first output (16) and a second output (18), wherein the first output is connected to the actuator input (40) of the first actuator (4) by means of a first shut-off valve (48) for blocking a flow in the direction of the first output (16), and the second output is connected to the actuator input (46) of the second actuator (6) by means of a second shut-off valve (50) for blocking a flow in the direction of the second output (18).

Description

Hydraulic control device, double clutch having such a control device, and method for operating such a control device

Technical Field

The invention relates to a hydraulic control device for actuating a dual clutch, a dual clutch having such a hydraulic control device, and a method for operating such a control device.

Background

Hydraulic control devices for actuating the double clutch are known from practice and have proven effective and accepted in actuating the speed of the double clutch.

Disclosure of Invention

The object of the present invention is to provide a hydraulic control device which has a particularly simple structure and which can achieve an energy-efficient control of the actuators of the double clutch. The basic object of the invention is also to provide a double clutch with such an advantageous control device. Finally, the object of the invention is to specify a method for operating such a hydraulic control device, which method makes it possible to achieve a particularly precise and flexible actuation of the clutch.

This object is achieved by the features given in claim 1, 9 or 10. Advantageous embodiments of the invention are the subject matter of the dependent claims.

The hydraulic control device according to the invention is preferably used for actuating a double clutch in a drive train of a motor vehicle, but other embodiments are also possible, such as actuating a brake, a claw clutch or a switchable freewheel. The hydraulic control device has a hydraulically actuatable actuator for the first clutch of the dual clutch. Furthermore, a second hydraulically actuatable actuator for a second clutch of the dual clutch is provided. The two actuators are preferably piston-cylinder assemblies. Furthermore, the hydraulic control device has a separate switching valve. The switching valve has an input, a first output connected to the actuator input of the first actuator by a first shut-off valve for blocking a flow in the direction of the first output, and a second output connected to the actuator input of the second actuator by a second shut-off valve for blocking a flow in the direction of the second output. The switching valve can be adjusted between a locking position, in which the flow between the input and the first and second output is blocked, a first position and a second position; in the first position, the input is connected to the first output and flow-through between the input and the second output is blocked; in the second position, the input is connected to the second output and flow communication between the input and the first output is blocked. The switching valve is preferably pretensioned into the blocking position or/and is designed as an electrically actuated valve, if appropriate as a proportional valve. Thus, separate switching valves are assigned to the two actuators and thus space-saving replacement of two separate switching valves for each actuator is possible, so that a particularly simple and compact construction can be achieved.

In a preferred embodiment of the control device according to the invention, the switching valve has an outlet which is optionally connected to the hydraulic fluid reservoir, wherein preferably the first output is connected to the outlet in the second position and/or the second output is connected to the outlet in the first position. Furthermore, in this embodiment it is particularly preferred that: the first output and the second output are connected to the outlet in a locked position or in an open position into which the switching valve can also be adjusted.

In a particularly preferred embodiment of the control device according to the invention, the input of the switching valve is connected to a hydraulic pump, preferably an electrically operated hydraulic pump, for generating an input pressure at the input. In this embodiment, the input pressure is preferably regulated or adjustable by means of a pressure regulating valve or a pressure relief valve. The pressure regulating valve or pressure relief valve can therefore open with its input line, for example laterally, into the line between the hydraulic pump (on the one hand) and the input of the switching valve (on the other hand). Furthermore, it is particularly preferred in this embodiment that: the hydraulic fluid which is derived from the pressure regulating valve or the pressure relief valve for setting the input pressure is or can be supplied to a cooling circuit, preferably a cooling circuit of a dual clutch or a control device, wherein this can be carried out if necessary via a transmission line. This embodiment is advantageous because the cooling circuit can be supported by the tapped hydraulic fluid and thus also the hydraulic pump, and the excess or tapped hydraulic fluid is thus meaningfully a cooling fluid.

In a further preferred embodiment of the control device according to the invention, a cooling fluid delivery pump is arranged in the cooling circuit. The cooling fluid delivery pump is preferably coupled to the hydraulic pump of the aforementioned control device and/or is driven or can be driven together with the hydraulic pump by a common electric motor in order to achieve a particularly simple construction and energy-efficient control and cooling. Furthermore, it is particularly preferred in this embodiment that: the cooling fluid in the cooling circuit can be selectively supplied to the region between the hydraulic pump and the input of the switching valve, which can be achieved if necessary by means of a corresponding connecting line. This has the advantage that the correspondingly supplied cooling fluid is meaningfully hydraulic fluid and the cooling fluid delivery pump can support the hydraulic pump, so that, for example, the actuator can be particularly quickly responded to or controlled.

According to an advantageous embodiment of the control device according to the invention, a second switching valve arranged on the output side of the aforementioned cooling fluid delivery pump is provided in the cooling circuit, which second switching valve can be adjusted from an open position, in which cooling fluid can be supplied to the component to be cooled via the second switching valve, and a discharge position, in which cooling fluid can be discharged into a cooling fluid container of the cooling circuit via the second switching valve. The second switching valve ensures, in its open position, normal cooling via the cooling circuit, while the second switching valve ensures, in the lead-out position, that the back pressure acting on the cooling fluid delivery pump is relatively small and thus relieves the load of the electric drive of the hydraulic pump coupled to the cooling fluid delivery pump and enables a greater power to be applied to actuate the actuator. Accordingly, a correspondingly simpler and smaller-structured motor can be selected for the common electric motor of the hydraulic pump and the cooling fluid delivery pump. In this case, a particularly energy-efficient control of the actuator and a particularly energy-efficient cooling of the component to be cooled can thus be achieved.

According to a further advantageous embodiment of the control device according to the invention, the second switching valve can also be adjusted to a locking position in which the second switching valve is locked, so that cooling fluid from the cooling fluid delivery pump can no longer reach the component to be cooled.

In a further advantageous embodiment of the control device according to the invention, the cooling circuit opens into the transmission line or/and the connection line between the cooling fluid feed pump and the second switching valve (if necessary the output side of the cooling fluid feed pump and the input side of the second switching valve).

According to a further advantageous embodiment of the control device according to the invention, further shut-off valves are arranged in the transfer line and/or in the connecting line. The shut-off valve in the connecting line then preferably prevents the cooling fluid from flowing from the cooling circuit in the direction of the outlet of the pressure regulating valve or the pressure relief valve, while the shut-off valve in the connecting line preferably prevents the hydraulic fluid from flowing in the direction of the cooling circuit, whereas the respective fluids can flow in the opposite direction, respectively. In particular, check valves and/or ball valves are provided as further shut-off valves.

In a further preferred embodiment of the control device according to the invention, the first shut-off valve can be switched to the open position independently of the switching valve, so that a flow in the direction of the first output of the switching valve is achieved. Alternatively or additionally, the second shut-off valve can be switched to the open position independently of the switching valve, so that a flow in the direction of the second outlet of the switching valve is achieved. Since the first or second shut-off valve can be switched or actuated independently of the switching valve, a particularly flexible control of the actuator and thus of the double clutch can be achieved.

In a further advantageous embodiment of the invention, the control device has, instead of the above-described embodiment, a switchable third shut-off valve for selectively discharging hydraulic medium from a region downstream of the first shut-off valve or/and a switchable fourth shut-off valve for selectively discharging hydraulic medium from a region downstream of the second shut-off valve. The third shut-off valve or/and the fourth shut-off valve can then preferably be switched independently of the first switching valve in order to achieve as flexible a control of the actuator as possible. Also particularly preferred in this embodiment is: the first shut-off valve and/or the second shut-off valve are designed to be non-switchable in comparison to the third shut-off valve and/or the fourth shut-off valve, i.e. are formed, for example, by simple check valves which react only to corresponding pressure differences at the input and output, but not to other (e.g. outward) actuation.

In a further advantageous embodiment of the control device according to the invention, the first shut-off valve and the second shut-off valve, if appropriate the third shut-off valve and the fourth shut-off valve or/and the further shut-off valve are designed as check valves or/and ball valves or/and pressure retaining valves or/and proportional valves in the transfer line or/and the connecting line.

The dual clutch according to the invention is preferably designed as a wet-running dual clutch, particularly preferably as a twin-plate clutch. The double clutch has a first clutch and a second clutch, regardless of the particular embodiment. Furthermore, a control device of the type according to the invention is proposed, a first actuator of which is assigned to the first clutch and a second actuator of which is assigned to the second clutch.

In a preferred embodiment of the dual clutch according to the invention, the cooling circuit is preferably assigned to the first clutch and the second clutch, particularly preferably to the clutch disks of the first clutch and the second clutch, in order to achieve an efficient cooling of both clutches or of their clutch disks.

The method according to the invention for operating the control device according to the invention has at least one of the two method steps of reducing the pressure at the actuator input of the first actuator by setting the first shut-off valve or the third shut-off valve in an oscillating manner between its closed position and its open position, or/and reducing the pressure at the actuator input of the second actuator by setting the second shut-off valve or the fourth shut-off valve in an oscillating manner between its closed position and its open position. It has been shown that in this way, the pressure at the input of the respective actuator can be achieved in a particularly advantageous manner and with little effort, with the desired time profile for achieving the pressure reduction. A particularly flexible actuation of the actuator can thus be achieved on the basis of such method steps.

In a preferred embodiment of the method according to the invention, the adjustment of such oscillations is performed at a frequency of at least 30 Hz, preferably at least 50 Hz or greater than 50 Hz.

Drawings

The invention is explained in detail below with reference to the figures by means of exemplary embodiments. In the drawings:

fig. 1 shows a schematic view of a first embodiment of a control device according to the invention;

fig. 2 shows a schematic view of a second embodiment of the control device according to the invention; and

fig. 3 shows a schematic view of a cooling circuit which supplements the control device of fig. 1 and 2.

Detailed Description

Fig. 1 shows a first embodiment of a hydraulic control apparatus 2. The control device 2 has a first hydraulically actuable actuator 4 for a first clutch of the double clutch, not shown in detail, and a second hydraulically actuable actuator 6 for a second clutch of the double clutch, not shown in detail. The first and second actuators 4, 6 are preferably designed as piston-cylinder assemblies, each having a cylinder 8 and a piston 10 guided displaceably in the cylinder 8.

Furthermore, the control device 2 has a separate switching valve 12, which is provided with an input 14, a first output 16 and a second output 18. The input 14 is connected via a line 20 to the output of a hydraulic pump 22, which on the input side can draw in hydraulic fluid from a fluid reservoir 24 via a filter 26. The hydraulic pump 22 is designed as an electrically operated hydraulic pump which is driven or drivable by an electric motor 28. A further filter 30 is arranged in the line 20, wherein the filter 30 is assigned a bypass component 32 which can be activated in the event of a blockage of the filter 30. The hydraulic pump 22 is adapted via line 20 to generate an input pressure at the input 14 of the switching valve 12.

However, the output pressure of the hydraulic pump 22 does not necessarily have to be used as the input pressure at the input 14 of the switching valve 12, but rather the input of a pressure regulating valve or pressure relief valve 34 opens into the line 20, so that the input pressure at the input 14 of the switching valve 12 is set or can be set via the pressure regulating valve or pressure relief valve 34. The hydraulic fluid which is led out of the line 20 by the pressure regulating valve or pressure relief valve 34 is supplied or can be supplied via a transmission line 36 to a cooling circuit 38 of the dual clutch or control device 2, wherein a possible embodiment of the cooling circuit 38 which shall be described in more detail later is illustrated in fig. 3. In fig. 1, a connection point a is shown, by means of which the transmission line 36 can be connected or connected to the cooling circuit 38 according to fig. 3.

A line 42 extends between the first output 16 of the switching valve 12 and the actuator input 40 of the first actuator 4, and a line 44 extends in a corresponding manner between the second output 18 of the switching valve 12 and the actuator input 46 of the second actuator 6. A first shut-off valve 48 is arranged in line 42, which serves to block the passage of hydraulic fluid from actuator input 40 in the direction of first output 16 of switching valve 12. A second shut-off valve 50 is arranged in the line 44 for blocking the passage of hydraulic fluid from the actuator input 46 in the direction of the second output 18 of the switching valve 12.

In the embodiment according to fig. 1, a switchable third shut-off valve 52 and a switchable fourth shut-off valve 54 are also provided. A switchable third shut-off valve 52 is used to selectively drain hydraulic fluid from the line 42 downstream of the first shut-off valve 48 and upstream of the actuator input 40 of the first actuator 4. In contrast, the switchable fourth cut-off valve 54 serves to selectively drain hydraulic fluid from the region of the line 44 downstream of the second cut-off valve 50 and upstream of the actuator input 46 of the second actuator 6. The third and fourth shut-off valves 52, 54 can be switched independently of the switching valve 12, so that the actuators 4, 6 can be controlled particularly flexibly. In contrast, the first and second shut-off valves 48, 50 are designed in the first embodiment according to fig. 1 to be non-switchable, but preferably in the form of simple check valves or/and ball valves or/and pressure-retaining valves. In addition, the line 42 and the line 44 are assigned a pressure sensor 56 or 58 in the region between the respective shut-off valve 48 or 50 (on the one hand) and the respective actuator input 40 or 46 (on the other hand). The actuating pressure applied to the respective actuator 4 or 6 can thus be detected by the pressure sensor 56 or 58.

As can be seen from fig. 1, the switching valve 12 can take up substantially three positions. The switching valve 12 can thus be adjusted between a locked position, in which the flow between the input 14 and the first and second outputs 16, 18 is blocked, a first position and a second position; in the first position, the input 14 is connected to the first output 16 and flow communication between the input 14 and the second output 18 is blocked; in the second position, the input 14 is connected to the second output 18 and flow communication between the input 14 and the first output 16 is blocked.

Furthermore, attention is first generally drawn to a connecting line 60 which opens into the line 20 and which can be connected or connected by means of a connecting point b to a cooling circuit 38 described in more detail below in order to support the hydraulic circuit.

Before discussing the already mentioned cooling circuit 38 according to fig. 3 and the connection of the cooling circuit to one of the two control devices 2 according to fig. 1 and 2 in more detail, the differences between the second embodiment of the control device 2 according to fig. 2 and the first embodiment according to fig. 1 will first be explained, wherein the main discussion differs, identical or similar components are provided with the same reference numerals, and the above description applies in each case in the remaining respects.

In the second embodiment according to fig. 2, the switching valve 12 also has an outlet 62 which is connected to a hydraulic fluid reservoir 64. In contrast to the switching valve 12 of fig. 1, the switching valve 12 is also designed such that the first output 16 is connected to the outlet 62 in the second position and the second output 18 is connected to the outlet 62 in the first position. In addition, the first and second outputs 16, 18 are connected to the outlet 62 in the locked position of the switching valve 12. In addition, in the second embodiment shown in fig. 2, it is preferred that the switching valve 12 can also be set to an open position, in which the first and second outputs 16, 18 are connected to the outlet 62.

As a further difference to the first embodiment according to fig. 1, it can be seen in the second embodiment according to fig. 2 that the third and fourth shut-off valves 52, 54 are omitted. The first and second shut-off valves 48, 50 are designed to be switchable, unlike the first embodiment. The first and second shut-off valves 48, 50 can therefore be switched into the open position independently of the switching valve 12, so that a flow in the direction of the first or second outlet 16 or 18 is possible.

Fig. 3 shows a cooling circuit 38 which is connected or can be connected by means of connection points a and b to the control device 2 according to fig. 1 or according to fig. 2. A cooling fluid delivery pump 66 is arranged in the cooling circuit 38, which can draw cooling fluid from the fluid reservoir 24 (as already described above with reference to the hydraulic pump 22) via the filter 26, as long as a small amount of cooling fluid is still present in the cooling circuit 38. At least one component to be cooled (designated by reference numeral 68) is also arranged in the cooling circuit 38. In the case of a dual clutch having such a control device 2, the components 68 to be cooled are preferably the clutch disks of the first and second clutch of the dual clutch, particularly preferably the first and second clutch, provided that the dual clutch is designed as a two-disk clutch. In addition, the double clutch is preferably designed as a wet-running double clutch or a twin-plate clutch. In the double clutch with the control device 2, the first actuator 4 is assigned to the first clutch of the double clutch and the second actuator 6 is assigned to the second clutch of the double clutch.

In contrast to the illustrations in fig. 1 and 2, the cooling fluid delivery pump 66 of the cooling circuit 38 shown in fig. 3 is coupled to the hydraulic pump 22, wherein the aforementioned electric motor 28 is designed as a common electric motor by means of which the cooling fluid delivery pump 66 is driven or can be driven together with the hydraulic pump 22. Such a coupling need not necessarily be present, rather the pumps can also be operated independently of one another, but the illustrated coupling to the common electric motor 28 is particularly advantageous.

The cooling circuit 38 has a line section 70 which extends from the output side of the cooling fluid feed pump 66 to the input of a second switching valve 72. The second switching valve 72 is connected on the output side via a line section 74 of the cooling circuit 38 to the component 68 to be cooled. On the output side of the component 68 to be cooled, a further line section 76 extends back to the input of the cooling fluid feed pump 66. Thus, the second switching valve 72 after the line section 70 is arranged on the output side of the cooling fluid feed pump 66, wherein the second switching valve 72 can be adjusted from an open position, in which the cooling fluid can be supplied to the component 68 to be cooled via the second switching valve 72, a lead-out position and a lock-up position; in the discharge position, the cooling fluid can be discharged via the second switching valve 72 into the cooling fluid container 78 of the cooling circuit 38; in the locked position, the second switching valve 72 is locked, so that neither the line section 74 nor the cooling fluid container 78 is supplied with cooling fluid.

Both the previously mentioned transfer line 36 and the previously described connection line 60 open into a line section 70 of the cooling circuit 38 between the output side of the cooling fluid feed pump 66 and a second switching valve 72. Furthermore, further shut-off valves 80, 82 are arranged in the transfer line 36 and the connection line 60. The further shut-off valve 80 prevents the cooling fluid from overflowing from the line section 70 into the transfer line 36, while the further shut-off valve 82 prevents the hydraulic fluid from overflowing from the connection line 60 into the line section 70 of the cooling circuit 38. Conversely, in the respective opposite direction, the hydraulic fluid or the cooling fluid can be flooded via the respective shut-off valve 80 or 82.

In particular, the cooling fluid can thus be selectively supplied from the line section 70 of the cooling circuit 38 via the further shut-off valve 82 and the connection line 60 to the region between the hydraulic pump 22 and the input 14 of the switching valve 12 in order to support the hydraulic actuation by the cooling fluid feed pump 66 and the cooling fluid. In addition to this, a relatively low-power electric motor 28 can be used on the basis of the second switching valve 72, since the back pressure acting on the cooling fluid delivery pump 66 via the cooling circuit 38 can be reduced by switching the second switching valve 72 into its outlet position.

It can also be seen for the two implementation variants according to fig. 1 and 2: the first and second shut-off valves 48, 50, if appropriate the third and fourth shut-off valves 52, 54 or/and the further shut-off valves 80, 82 are preferably designed as check valves or/and ball valves or/and pressure-retaining valves or/and proportional valves.

In both embodiments according to fig. 1 and 2, the pressure regulating valve or relief valve 34 regulates or limits the input pressure at the input 14 of the switching valve 12. Depending on the position of the switching valve 12, the following operating modes can be set:

a) The switching valve 12 may be adjusted to a lock-up position so that hydraulic fluid provided by the hydraulic pump 22 may be supplied to the cooling circuit 38 via the pressure regulating valve or pressure relief valve 34. Control of the cooling fluid pressure may be controlled by the speed of the electric motor 28 used to drive the hydraulic pump 22 or the cooling fluid delivery pump 66;

b) The switching valve 12 in the first position causes hydraulic fluid to be supplied to the first actuator 4 via the first shut-off valve 48;

c) The switching valve 12 in the second position causes hydraulic fluid to be supplied to the second actuator 6 via the second shut-off valve 50.

If the first or second actuator 4;6 is sufficiently supplied, the first or second stop valve 48; 50. if necessary, a third or fourth shut-off valve 52;54 will maintain the corresponding actuator 4; 6. The switching valve 12 can be switched back into the locked position, and the speed of the hydraulic pump 22 can be reduced and adapted to the supply of the cooling circuit 38, wherein the switching valve 12 is preferably pretensioned into its locked position. In the event of a possible pressure loss, the hydraulic pump 22 can be used again for a short time for pressure build-up, so that the associated actuator 4 is brought via the switching valve 12 in the corresponding position; the pressure at 6 rises again.

If the first actuator 4 should not be actuated, but the second actuator 6 should be actuated, the switching valve 12 is switched to the second position. Even so, the hydraulic fluid can be disengaged from the first actuator 4 by means of the third shut-off valve 52 (see fig. 1) or the first shut-off valve 48 (see fig. 2), wherein the associated shut-off valve 52;48 are preferably opened or closed in an oscillating manner (preferably at a frequency of at least 25 Hz, particularly preferably at a frequency of at least 50 Hz or greater than 50 Hz). When the second actuator 6 should not be actuated, but the first actuator 4 should be actuated, the reverse is done.

Advantageous method steps of the method according to the invention for operating the control device 2 according to the preceding figures are also described here. Generally, by connecting the first or third shut-off valve 48;52 are oscillatingly adjusted between the locked position and the open position to reduce the pressure at the actuator input 40 of the first actuator 4. Alternatively or additionally, by connecting the second or fourth cut-off valve 50;54 are oscillatingly adjusted between the locked position and the open position to reduce the pressure at the actuator input 46 of the second actuator 6. It has already been pointed out above that the adjustment of such oscillations is preferably carried out here at a frequency of at least 25 Hz, particularly preferably at least 50 Hz, if appropriate greater than 50 Hz.

List of reference numerals

2. Control device

4. First actuator

6. Second actuator

8. Cylinder body

10. Piston

12. Switching valve

14. Input terminal

16. A first output terminal

18. Second output terminal

20. Line

22. Hydraulic pump

24. Fluid storage device

26. Filter

28. Electric motor

30. Filter

32. Bypass assembly

34. Pressure regulating valve/pressure relief valve

36. Transmission line

38. Cooling circuit

40. Actuator input

42. Line

44. Line

46. Actuator input

48. First stop valve

50. Second stop valve

52. Third stop valve

54. Fourth stop valve

56. Pressure sensor

58. Pressure sensor

60. Connecting line

62. An outlet

64. Hydraulic fluid container

66. Cooling fluid delivery pump

68. Component

70. Line segment

72. Second switching valve

74. Line segment

76. Line segment

78. Cooling fluid container

80. Additional shut-off valves

82. Additional shut-off valves

a connection point

b connecting points.

Claims (10)

1. A hydraulic control device (2) for operating a dual clutch, the hydraulic control device having:

a hydraulically actuatable first actuator (4) for a first clutch of the dual clutch;

a second hydraulically actuatable actuator (6) for a second clutch of the dual clutch; and

a separate switching valve (12) having an input (14), a first output (16) and a second output (18), wherein the first output is connected to an actuator input (40) of the first actuator (4) by means of a first shut-off valve (48) for blocking a flow in the direction of the first output (16), and the second output is connected to an actuator input (46) of the second actuator (6) by means of a second shut-off valve (50) for blocking a flow in the direction of the second output (18),

wherein the switching valve (12) is adjustable between a locking position, in which the communication between the input (14) and the first and second outputs (16, 18) is blocked, a first position and a second position; in the first position, the input (14) is connected to the first output (16) and flow between the input (14) and the second output (18) is blocked; in the second position, the input (14) is connected to the second output (18) and the flow between the input (14) and the first output (16) is blocked.

2. The hydraulic control device (2) as claimed in claim 1, characterized in that the switching valve (12) has an outlet (62) which is connected, if necessary, to a hydraulic fluid reservoir (64), wherein preferably the first output (16) is connected in the second position to the outlet (62) or/and the second output (18) is connected in the first position to the outlet (62), and particularly preferably the first and second outputs (16, 18) are connected in the locked position or in an open position into which the switching valve (12) can also be adjusted to the outlet (62).

3. The hydraulic control device (2) as claimed in one of the preceding claims, characterized in that the input (14) is connected with a hydraulic pump (22) for generating an input pressure at the input (14), if necessary with an electrically operated hydraulic pump (22), wherein the input pressure is preferably set or can be set by means of a pressure regulating or pressure relief valve (34), and the hydraulic fluid which is derived from the pressure regulating or pressure relief valve (34) for setting the input pressure is particularly preferably supplied or can be supplied to a cooling circuit (38), if necessary a cooling circuit (38) of the double clutch or the control device (2), via a transmission line (36).

4. The hydraulic control device (2) as claimed in claim 3, characterized in that a cooling fluid delivery pump (66) is arranged in the cooling circuit (38), wherein the cooling fluid delivery pump (66) is preferably coupled with the hydraulic pump (22) or/and is driven or can be driven together with the hydraulic pump (22) by means of a common electric motor (28), and cooling fluid from the cooling circuit (38) can particularly preferably be selectively supplied to a region between the hydraulic pump (22) and the input (14) of the switching valve (12) via a connection line (60) if necessary.

5. The hydraulic control apparatus (2) as claimed in claim 4, characterized in that a second switching valve (72) arranged on the output side of the cooling fluid feed pump (66) is provided in the cooling circuit (38), which second switching valve can be adjusted from an open position, in which the cooling fluid can be supplied to a component (68) to be cooled via the second switching valve (72), a lead-out position and, if necessary, a lock-up position; in the discharge position, the cooling fluid can be discharged into a cooling fluid container (78) of the cooling circuit (38) via the second switching valve (72); in the locked position, the second switching valve (72) is locked, wherein the transfer line (36) or/and the connecting line (60) preferably open into the cooling circuit (38) between the cooling fluid feed pump (66) and the second switching valve (72), and a further shut-off valve (80.

6. The hydraulic control device (2) according to any one of the preceding claims, characterized in that the first or/and the second shut-off valve (48.

7. The hydraulic control apparatus (2) as claimed in one of claims 1 to 5, characterized in that a switchable third shut-off valve (52) for selectively discharging hydraulic medium from a region downstream of the first shut-off valve (48) or/and a switchable fourth shut-off valve (54) for selectively discharging hydraulic medium from a region downstream of the second shut-off valve (50) are provided, wherein the third shut-off valve (52) or/and the fourth shut-off valve (54) can preferably be switched independently of the switching valve (12), and the first shut-off valve or/and the second shut-off valve (48.

8. Hydraulic control device (2) according to any one of the preceding claims, characterised in that the first and second shut-off valves (48, 50), if necessary third and fourth shut-off valves (52, 54) or/and the further shut-off valves (80, 82) are designed as check valves or/and ball valves or/and pressure retaining valves or/and proportional valves.

9. Double clutch, preferably wet-running double clutch, particularly preferably twin-plate clutch, with a first clutch and a second clutch, characterized in that a control device (2) according to one of the preceding claims is provided, a first actuator (4) of which is assigned to the first clutch and a second actuator (6) of which is assigned to the second clutch, wherein the cooling circuit (38) is preferably assigned to the first clutch and the second clutch, particularly preferably to the clutch plates of the first clutch and the second clutch.

10. Method for operating a control device (2) according to one of claims 1 to 9, comprising the following method steps:

reducing the pressure at the actuator input (40) of the first actuator (4) by adjusting the first or third shut-off valve (48; or/and

reducing the pressure at the actuator input (46) of the second actuator (6) by adjusting the second or fourth shut-off valve (50,

wherein the adjustment of the oscillation is preferably carried out at a frequency of at least 25 Hz, particularly preferably at a frequency of at least 50 Hz or more than 50 Hz.

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