Hydraulic assembly, hydraulic actuation consumer comprising the hydraulic assembly and method of hydraulic actuation of a consumer

Abstract

The invention relates to a hydraulic assembly (10) comprising a lubricant output (16), a control output (20) and a pump (22) which is able to supply a flow of hydraulic fluid to the lubricant output (16) and to the control output (20), wherein a switching valve (30) with a structurally predetermined hysteresis is arranged between the pump output (26) and the control output (20) of the hydraulic assembly (10) and is able to switch between an open position, in which the control output (20) is connected to the pump output (26), and a blocked position, in which the control output (20) is blocked, as a function of the pressure in the branch between the pump output (26) and the control output (20), wherein the switching valve (30) switches from the open position to the blocked position when the pressure provided by the pump (22) exceeds an upper switching threshold and switches from the blocked position back to the open position when the pressure provided by the pump (22) falls below a lower switching threshold. The invention also relates to a clutch which is switched by means of such a hydraulic assembly and to a method of actuating a clutch.

Description

Technical Field

[0001] The present invention relates to a hydraulic component, a hydraulic actuation consumption device having such a hydraulic component, and a hydraulic actuation method for the consumption device. Background Technology

[0002] Hydraulic components are particularly useful in (partially) electrically driven vehicles to switch the clutch as needed, such as when shifting from first gear to second gear or vice versa. It is also conceivable to engage or disengage the motor via clutch actuation. Other application examples include hydraulically actuated consumable devices that generate back pressure in vehicles.

[0003] In addition, hydraulic components can be used, for example, to supply current / lubricant flow to a transmission that is assigned to a clutch or to a motor, battery, heat exchanger, power electronic component, etc., used for that clutch or another clutch.

[0004] In principle, in motor vehicles, it is desirable for hydraulic components to require as little energy as possible. This applies even more broadly in electric vehicles, as the energy consumption of auxiliary equipment reduces the maximum stroke. Summary of the Invention

[0005] The object of this invention is to create a hydraulic assembly that, with minimal energy consumption and low structural complexity, firstly provides a coolant / lubricant flow, and secondly, allows the clutch to operate as needed (and preferably to operate continuously in the current state and be maintained in an energy-efficient manner).

[0006] To achieve this objective, according to the present invention, a hydraulic assembly is provided having a lubricant output section, a control output section, and a pump capable of supplying hydraulic fluid flow to the lubricant output section and the control output section. A structurally predetermined hysteresis switching valve is arranged between the pump output section and the control output section of the hydraulic assembly. This switching valve is capable of switching between an open position and a closed position based on the pressure in the branch between the pump output section and the control output section. In the open position, the control output section is connected to the pump output section; in the closed position, the control output section is blocked. The switching valve switches from the open position to the closed position when the pressure supplied by the pump exceeds an upper switching threshold, and returns from the closed position to the open position when the pressure supplied by the pump drops below a lower switching threshold.

[0007] In addition, to achieve this purpose, a clutch is provided, which has such a hydraulic assembly, a clutch actuator connected to a control output of the hydraulic assembly, and a reset device for loading the clutch to a position and resisting the action of the clutch actuator.

[0008] Finally, to achieve this objective, a method for switching such a clutch is provided, wherein hydraulic fluid is supplied to the clutch actuator via a control output to switch the consumable device from one state to another, wherein a switching valve is loaded to the open position by a reset device, wherein a pump operates at a starting speed with a pressure below an upper switching threshold, and the supplied hydraulic fluid is output via a lubricant output; wherein, if the clutch is to be switched, the pump speed is increased such that hydraulic fluid is initially supplied to the clutch actuator, and once the clutch actuator has been operated, the hydraulic fluid accumulates in the branch of the control output until it exceeds the upper switching threshold, thereby causing the switching valve to enter a blocking state; wherein, the pump is then decelerated again to the starting speed, and the switching valve remains in the blocking state due to a structurally predetermined hysteresis; wherein, finally, when the clutch is to be switched back, the pump speed is reduced or reversed such that the speed drops below the lower switching threshold, and the switching valve returns to the open position.

[0009] By using hydraulic components, the clutch can be switched, and then the switching valve can be brought into the blocking position, so that the clutch remains in its switched state (e.g., closed state). For this purpose, no active external actuation valve is required; instead, the clutch can be switched and locked in the switched state simply by changes in pressure supplied by the pump. The basic concept of the invention is to equip the switching valve with a structurally predetermined hysteresis. In this context, the term "structurally predetermined hysteresis" means that the switching valve is structurally designed such that moving the switching valve from the open position to the blocking position requires a relatively high pressure (above the upper switching threshold), and that the applied pressure must first decrease significantly (i.e., below the lower switching threshold) before the switching valve returns to the open position. The structurally predetermined hysteresis is based on structural features, such as different cross-sectional ratios, and is thus distinguished from the hysteresis that is essentially attributable to friction.

[0010] According to one embodiment of the invention, the upper limit switching threshold is at least twice the lower limit switching threshold. The difference between the upper and lower limit switching thresholds can even be chosen to be larger. For example, the upper and lower limit switching thresholds can differ by a factor of three. In absolute terms, for automotive applications, a difference of approximately 10 to 15 bar between the lower and upper limit switching thresholds has proven advantageous.

[0011] The difference between the upper and lower switching thresholds allows the pump to operate in a "normal state," where it only needs to provide coolant / lubricant flow at a starting speed of, for example, approximately 1000 rpm, and only briefly increases the pump speed, for example, to 3000 rpm, when the switching process is triggered. The pump speed can then be immediately reduced back to the starting speed. Therefore, the pump requires relatively little drive power during normal operation. When the switching valve needs to return from the blocked position to the open position, the pump speed is briefly reduced again to lower the pressure in the branch between the pump output and the control connection. This allows the clutch to disengage within a timeframe of 0.4 to 0.8 seconds after the pump speed reduction. If an even faster response is desired, the pump's rotation direction can be briefly reversed to create negative pressure. In this way, even shorter switching times can be achieved, such as approximately 0.2 to 0.5 seconds.

[0012] According to an embodiment of the invention, the switching valve has an actuating piston exposed to pressure in a branch between the pump output and the control output. With the aid of the actuating piston, the switching valve can be switched between an open and closed position using pressure on the pump's delivery side with minimal structural complexity.

[0013] According to a preferred embodiment, the actuating piston is arranged in a cylinder having a pressure connection that connects to a branch between the pump output and the control output. When the switching valve is in the open position, the working face of the actuating piston rests on the pressure connection, closing it. The cross-sectional area of ​​the pressure connection is smaller than the area of ​​the working face. When the switching valve is in the open position, only a small portion of the working face of the actuating piston is exposed to the pressure at the pressure connection, and therefore to the pressure in the branch between the pump output and the control output, requiring a relatively high pressure to move the actuating piston, for example, to overcome the effect of the spring that loads the switching valve to the open position. However, once the working face of the actuating piston moves away from the pressure connection, the entire working face of the actuating piston is loaded with the pressure of the pressure connection (and therefore the pressure in the branch between the pump output and the control output). Accordingly, a very large force acts on the actuating piston. Due to this large force, the actuating piston initially switches the switching valve to the closed position very quickly. Secondly, the pressure acting on the working end face must decrease significantly before the force generated by the actuating piston drops enough to allow the switching valve to move back to the open position. By utilizing the different cross-sections of the pressure connection on one side and the working end face on the other, a structurally predetermined hysteresis can be set in a desired manner using a very simple method.

[0014] A bypass channel can be provided that connects the pump output to the control output, bypassing the switching valve. A check valve is installed in the bypass channel to block backflow from the control output to the pump output. This allows further hydraulic fluid to be delivered to the control output even when the switching valve is in the blocked position.

[0015] Preferably, a throttle is arranged between the pump output section and the lubricant output section so that a specific accumulation pressure is generated when the pump speed increases.

[0016] Pumps, in particular, can be designed to be single-flow, making them economical to produce.

[0017] To drive the pump, a conventional motor can be used, which allows the pump's rotation direction to be adapted in the desired manner or even reversed if needed with minimal control complexity.

[0018] When the clutch actuator switches over the action of the reset device, the pressure is lower than the upper switching threshold, causing the clutch to close first, and then the switching valve switches to the blocking position.

[0019] The clutch may have a so-called central release device, also known as CSC (concentric driven cylinder). This device is hydraulically sealed so that the clutch remains in the switched position when the switching valve has already entered the blocking position. Attached Figure Description

[0020] The present invention will now be described based on embodiments shown in the accompanying drawings. In the drawings:

[0021] Figure 1 A clutch according to the invention is schematically shown, which has a hydraulic assembly according to a first embodiment of the invention;

[0022] Figure 2 schematically shown Figure 1 The hydraulic assembly according to the present invention;

[0023] Figure 3 Detailed illustration Figure 2 A switching valve used in a hydraulic assembly, wherein the valve is in the open position;

[0024] Figure 4 The image shows the position of the block. Figure 3 The switching valve;

[0025] Figure 5 A schematic diagram of the hysteresis of the switching valve is shown;

[0026] Figure 6 A hydraulic assembly according to a second embodiment is schematically shown;

[0027] Figure 7A hydraulic assembly according to a third embodiment is schematically shown; and

[0028] Figure 8 A hydraulic assembly according to a fourth embodiment is schematically shown. Detailed Implementation

[0029] Figure 1 Motor 1 is schematically shown, connected to gearbox 2, which is also schematically shown. Gearbox 2 is used to change the speed of the motor in a desired manner. For this purpose, the gearbox has two or more gears. The input power of motor 1 is output from gearbox 2 via output shaft 3.

[0030] A clutch 4 is provided for switching between different transition stages. A clutch actuator 5 is assigned to the clutch 4 and can switch the clutch between an open position and a closed position (or vice versa).

[0031] The precise structure of the transmission 2 and clutch 4 is irrelevant here. The only important factor is that the clutch actuator 5 can move the clutch against the action of the reset device. If the reset device loads the clutch 4 into the open position, the clutch 4 can be closed by the operation of the clutch actuator 5, and vice versa.

[0032] The clutch can be a friction clutch or a claw clutch.

[0033] The clutch actuator 5 can be a so-called central release device, also known as CSC (concentric driven cylinder).

[0034] Hydraulic components 10, which can draw hydraulic fluid from storage tank 12 through inlet line 14, are assigned to transmission 2 and clutch 4, or more precisely, clutch actuator 5 of clutch 4.

[0035] Although the hydraulic assembly 10 is assigned herein to the clutch actuator 5, in principle the hydraulic assembly 10 can also be used in a variety of other applications where a coolant / lubricant flow is required first, and a pressurized hydraulic fluid flow is required for operating the hydraulically actuated consumable device.

[0036] The hydraulic assembly 10 has a lubricant outlet 16 through which hydraulic fluid can be output to the transmission 2 and / or the clutch 4 to lubricate the components there. This is indicated by a lubricant nozzle 18. The hydraulic assembly 10 also includes a control output 20 through which hydraulic fluid can be output to the clutch actuator 5.

[0037] A return line 21 is also provided, through which hydraulic fluid can return from the transmission 2 to the storage tank 12.

[0038] Here, the storage device 12 can be integrated into the hydraulic assembly 10, integrated into the transmission 2, or configured as a separate component.

[0039] Hydraulic assembly 10 (see) Figure 2 It has a pump 22 driven by a drive motor 24. The drive motor is in particular a motor that can drive the pump 22 at a variable speed and, if necessary, in two opposite directions of rotation.

[0040] Pump 22 is a single-flow hydraulic pump. Precise structure is irrelevant here.

[0041] Pump 22 has a pump output section 26, which is connected to lubricant output section 16 and control output section 20.

[0042] Throttling device 28 is assigned to lubricant output section 16 so that pressure can be accumulated upstream of throttle device 28 according to the delivery flow of pump 22 and the pressure-volume demand of hydraulic actuation device (i.e. clutch 4 in this case).

[0043] A switching valve 30, which can switch between an open position and a closed position, is arranged between the control output section 20 of the hydraulic assembly 10 and the pump output section 26 of the pump 22. The switching valve 30 is connected upstream of the throttle 28, so that the accumulated pressure generated by the throttle 28 also exists in the branch leading to the control output section 20.

[0044] In the open position of the switching valve 30, the pump output 26 of the pump 22 is connected to the control output 20 of the hydraulic assembly 10. In the closed position of the switching valve 30, the control output 20 is blocked, so that the hydraulic fluid delivered to the clutch actuator 5 via the control output 20 and the hydraulic pressure generated in that branch remain "locked".

[0045] The switching valve 30 switches between an open position and a closed position based on the pressure in the branch between the pump output section 26 and the control output section 20. The corresponding switching mechanism is in... Figure 2 The figure is indicated by reference numeral 32 in the attached figure.

[0046] The switching valve 30, and especially the switching mechanism 32, generally possesses a structurally predetermined hysteresis. This "structurally predetermined hysteresis" is characterized by a relatively large difference between the upper and lower switching thresholds—that is, between the threshold for switching the valve from the open to the closed position and the threshold for switching the valve 30 from the closed position back to the open position. This difference can be set through structural measures. Therefore, the structurally predetermined hysteresis differs from the hysteresis inherent in each switching valve, particularly due to friction. This unavoidable hysteresis also exists in the switching valve 30. However, compared to the structurally predetermined hysteresis, its impact on switching behavior is negligible.

[0047] The switching valve 30 is equipped with a bypass passage 34, in which a check valve 36 is arranged. The check valve blocks the flow from the control output 20 to the lubricant output 16.

[0048] Figure 3 and Figure 4 An exemplary embodiment of the switching mechanism 32 for the switching valve 30 is shown.

[0049] The switching mechanism has a reset device 40 configured, for example, as a compression spring. The reset device loads the switching valve 30 into the open position.

[0050] Furthermore, the switching mechanism 32 has a cylinder 42 in which an actuating piston 44 is arranged. When the working end face 46 of the actuating piston 44 is pressurized, the switching valve can overcome the action of the spring 40 from the open position (see...). Figure 3 Enter the blocking position (see) Figure 4 ).

[0051] The cylinder body 42 has a pressure connection part 48, the cross-sectional area of ​​which is A. 48 The cross-sectional area A of the working end face 46 of the actuating piston 44 46 Much smaller. The size difference between the areas is at least 2 times, preferably at least 5 times.

[0052] In the open position of switching valve 30 (see...) Figure 3 The working end face 46 of the actuating piston 44 is located on the pressure connection 48 and is closed. Therefore, only a small portion of the working end face 46 of the actuating piston 44 is exposed to the pressure at the pump output 26 of the pump 22.

[0053] Once the working end face 46 of the actuating piston 44 moves away from the pressure connection 48, the hydraulic fluid that still flows into the actuating piston 44 through the pressure connection 48 acts on the entire working end face 46 of the actuating piston 44. Therefore, the resultant force applied to the actuating piston 44 is much higher, but the applied pressure is the same.

[0054] The structurally predetermined switching hysteresis is due to the different action sections of the pressure present at the pressure connection 48 (small action section A when the switching valve 30 is in the closed position). 48 When the switching valve is in the blocking position, the maximum operating cross-section A is reached. 46 This is caused by the switching valve 30 being in the blocked position. When the switching valve 30 is in the blocked position, the pressure acting on the working end face 46 must drop to a level far lower than the pressure required for the switching valve to switch from the open position to the closed position.

[0055] Due to the predetermined structural hysteresis, clutch 4 can operate as follows:

[0056] Assume clutch 4 is open in the starting state. Pump 22 can then operate at a starting speed (e.g., 1000 rpm), in which state the delivered hydraulic fluid is output to lubricant nozzle 18 via lubricant outlet 16. The pressure present at pressure connection 48 is very low, causing the pressure to be low across section A. 48 The force acting on the working end face 46 is less than the preload force of the spring 40; the switching valve 30 remains in the open position. In this state, because the switching valve 30 is open, the pressure present at the clutch actuator 5 is not high enough to close the clutch 4.

[0057] When the clutch is to be operated, i.e., engaged, the speed of pump 22 increases briefly, for example, to 3000 rpm. Due to the accumulation effect of throttle 28, the pressure in the branch leading to control output 20 increases, causing clutch actuator 5 to supply sufficient hydraulic fluid to engage clutch 4. When clutch 4 is engaged, the accumulated pressure in the branch leading to control output 20 rises sharply. Once it reaches, for example, a value of 15 bar, the pressure increases through section A. 48 The force generated on the working end face 46 of the actuating piston 44 is greater than the restoring effect of the spring 40, and the switching valve 30 from Figure 3 The opening position shown in the image is moved to... Figure 4 The blocking location is shown in the image.

[0058] The pump speed can then be reduced again immediately. Despite the decrease in delivery pressure, switching valve 30 remains in the blocked position because the lower pressure acts on the larger cross-section A. 46 Although pump 22 is now operating at its starting speed again, and there is only low build-up pressure in branch 20, switching valve 30 remains in the blocked position, thereby keeping clutch 4 in the closed position.

[0059] If necessary, the clutch actuator 5 can still be supplied with hydraulic fluid via the bypass passage 34 even when the switching valve 30 is in the blocked position.

[0060] Because of the bypass valve 36, the switching valve can be switched first when the pump pressure increases, and then only the clutch can be switched at higher pressures, since the hydraulic fluid is supplied via the bypass valve instead of the switching valve.

[0061] When clutch 4 disengages again, it must be ensured that the pressure in cylinder 42 drops sufficiently so that the action of spring 40 exceeds the force exerted on actuating piston 44 by the pressure acting on working end face 46. The operating pressure can be reduced by decreasing the speed of pump 22 sufficiently to reduce the accumulated pressure upstream of throttle 28, or by briefly reversing the pump's rotation to create a suction effect on the pump output 26 side. Therefore, switching valve 30 returns to the open position (see...). Figure 3The clutch actuator 5 discharges air toward the transmission via the control output section 20, the open switching valve 30, and the lubricant output section 16.

[0062] Pump 22 can then operate again at the starting speed, allowing hydraulic fluid to be supplied to the transmission for lubrication purposes. The brief reduction or interruption of lubricant supply when the clutch is disengaged generally has no detrimental effect on lubrication. Similarly, the brief increase in current / lubricant flow when actuating the clutch at, for example, an electric motor speed of 3000 rpm also has no adverse effects.

[0063] Figure 5 The diagram shows the predetermined hysteresis in the structure of the switching valve 30.

[0064] The pressure is shown on the X-axis, where P on The pressure indicating the transition from the open position to the closed position, and P off Indicates the pressure required to transition from the blocked position to the open position.

[0065] On the Y-axis, "1" indicates the blocked position and "0" indicates the open position.

[0066] Upper limit switching threshold ("P") on ") and lower limit switching threshold ("P off The difference between the values ​​allows the pump to operate in a "normal state," where it only provides a coolant / lubricant flow. This state exists before and after clutch actuator operation.

[0067] Figure 6 A hydraulic assembly according to a second embodiment is shown. The same reference numerals are used for components and features known from the first embodiment, and reference is made to the description above to this extent.

[0068] The difference between the second embodiment and the first embodiment is that, in the second embodiment, the check valve is not arranged in the bypass channel, but is integrated into the switching valve 30. In the open position, hydraulic fluid can pass through unimpeded, as in the first embodiment. In the closed position of the switching valve 30, hydraulic fluid can still be delivered directly through the check valve 36' in the switching valve.

[0069] Figure 7 A hydraulic assembly according to a third embodiment is shown. The same reference numerals are used for components and features known from the foregoing embodiments, and reference is made to the description above to this extent.

[0070] The difference between the third embodiment and the previous embodiments is that, in the third embodiment, a throttle valve 28' is provided instead of a flow throttle, which allows switching between a free-flowing position and a flow-blocking position. In this way, energy consumption can be further reduced when the control valve 30 is not switched, that is, when pressure accumulation is not required at the output 26.

[0071] Figure 8 A hydraulic assembly according to a fourth embodiment is shown. The same reference numerals are used for components and features known from the foregoing embodiments, and reference is made to the description above to this extent.

[0072] The difference between the fourth embodiment and the third embodiment is that, in the fourth embodiment, a proportional valve 28" is provided, which can be used to generate accumulated pressure when needed.

[0073] The advantage of the proportional valve 28" is that it can close completely in a short time. This allows the clutch actuator 5 to be filled with hydraulic fluid even faster, providing a particularly short response time.

[0074] Therefore, the proportional valve can be set to maintain a specific build-up pressure while the switching valve 30 remains closed. Simultaneously, with the switching valve 30 closed, the coolant / lubricant flow 16 can be set to be extremely variable through the combination of the rotational speed of the motor 24 and the energization of the proportional valve 28" (from almost no coolant / lubricant flow to a very large coolant / lubricant flow), because the build-up pressure for the switching valve 30 can be maintained.

Claims

1. A hydraulic assembly (10), comprising: The system includes a lubricant output section (16), a control output section (20), and a pump (22), the pump being capable of supplying hydraulic fluid flow to the lubricant output section (16) and the control output section (20). A switching valve (30) is arranged between the pump output section (26) and the control output section (20) of the hydraulic assembly (10), and the switching valve is capable of switching between an open position and a closed position according to the pressure in the branch between the pump output section (26) and the control output section (20). In the open position, the control output section (20) is connected to the pump. Output unit (26), in the blocked position, the control output unit (20) is blocked, wherein when the pressure provided by the pump (22) exceeds the upper limit switching threshold, the switching valve (30) switches from the open position to the blocked position, and when the pressure provided by the pump (22) drops below the lower limit switching threshold, the switching valve returns from the blocked position to the open position, wherein the upper limit switching threshold and the lower limit switching threshold are defined by a structurally predetermined hysteresis of the switching valve (30), the structurally predetermined hysteresis being based on structural features.

2. The hydraulic assembly (10) according to claim 1, characterized in that, The upper limit switching threshold is at least twice the lower limit switching threshold.

3. The hydraulic assembly (10) according to claim 1 or 2, characterized in that, The switching valve (30) has an actuating element (44) exposed to pressure in the branch between the pump output (26) and the control output (20).

4. The hydraulic assembly (10) according to claim 3, characterized in that, The actuating element is an actuating piston (44), which is arranged in a cylinder (42) having a pressure connection (48) connected to a branch between the pump output (26) and the control output (20). When the switching valve (30) is in the open position, the working end face (46) of the actuating piston (44) rests on the pressure connection (48) and closes the pressure connection. The cross-sectional area (A) of the pressure connection (48) is... 48 The area of ​​the working end face is smaller than that of the working end face (A). 46 ).

5. The hydraulic assembly (10) according to claim 1 or 2, characterized in that, The switching valve (30) is loaded into the open position by the reset element (40).

6. The hydraulic assembly (10) according to claim 5, characterized in that, The reset element is a spring (30), a permanent magnet, a mass component subjected to gravity, or a pneumatic component.

7. The hydraulic assembly (10) according to claim 1 or 2, characterized in that, A bypass channel (34) is provided, which bypasses the switching valve (30) and connects the pump output section (26) to the control output section (20). A check valve is provided in the bypass channel (34) to block the backflow from the control output section (20) to the pump output section (26).

8. The hydraulic assembly (10) according to claim 1 or 2, characterized in that, The check valve is integrated into the switching valve (30).

9. The hydraulic assembly (10) according to claim 1 or 2, characterized in that, The throttle (28) is arranged between the pump output (26) and the lubricant output (16), downstream of the branch leading to the switching valve (30).

10. The hydraulic assembly (10) according to claim 1 or 2, characterized in that, A throttle valve (28') capable of switching between a free-flowing position and a blocked-flow position is arranged between the pump output (26) and the lubricant output (16), downstream of the branch leading to the switching valve (30).

11. A hydraulic actuation consumption device that generates a reaction force during operation, the hydraulic actuation consumption device comprising a hydraulic assembly (10) according to any one of the preceding claims, an actuator (5) connected to a control output (20) of the hydraulic assembly (10), and a reset device for loading the hydraulic actuation consumption device to a position and resisting the action of the actuator (5).

12. The hydraulic actuation consumption device according to claim 11, characterized in that, The pressure at which the actuator (5) switches over the effect of the reset device is lower than the upper limit switching threshold.

13. The hydraulic actuation consumption device according to claim 11, characterized in that, The hydraulic assembly (10) is provided with a bypass channel (34), in which a check valve is provided, and the hydraulic actuation consumption device is actuated via the bypass channel (34).

14. The hydraulic actuation consumption device according to claim 11, characterized in that, The hydraulic actuation consumption device is a clutch (4).

15. A method for switching the hydraulic actuation consumable device according to any one of claims 11 to 14, wherein, Hydraulic fluid is supplied to the actuator (5) via the control output unit (20) to switch the hydraulic actuation device from one state to another, wherein the switching valve (30) is loaded to the open position by a reset element. The pump (22) operates at a starting speed with a pressure lower than the upper limit switching threshold, and the hydraulic fluid delivered is output via the lubricant output section (16); If the hydraulic actuation consumption device is to be switched, the speed of the pump (22) is increased so that hydraulic fluid is supplied to the actuator (5) first, and once the hydraulic actuation consumption device has been operated, the hydraulic fluid accumulates in the branch of the control output unit (20) until it exceeds the upper limit switching threshold, thereby causing the switching valve (30) to enter the blocking state. Then the speed of the pump (22) is reduced again to the starting speed, wherein the switching valve (30) remains in the blocking state due to a structurally predetermined hysteresis; Finally, when the hydraulic actuation consumption device needs to switch back, the speed of the pump (22) is reduced or reversed, causing the speed to drop below the lower limit switching threshold, and the switching valve (30) returns to the open position.

16. The method according to claim 15, characterized in that, The hydraulic assembly (10) includes a bypass passage (34) with a check valve, or the switching valve (30) integrates a check valve. When the switching valve (30) is closed, the pump (22) increases its speed so that hydraulic fluid is still delivered to the actuator (5) via the check valve.

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