Electro-hydraulic actuator unit

Abstract

The invention relates to an electro-hydraulic actuator unit (10) having a valve unit (14), the electro-hydraulic actuator unit (10) being connected to a pump unit (16) and to an actuator unit (12) such that the valve unit (14) at least partially controls a deflection of the actuator unit (12), the valve unit (14) being designed to control a flow of a fluid via a valve element (18) of the valve unit (14), the valve unit (14) is designed to set the actuator unit (10) in a safe state if a pressure increase in the fluid, in particular due to a fault, exceeds a predetermined limit value, in which a predetermined pressure, in particular a nearly non-pressure state, is established in the fluid.

Description

Technical Field

[0001] This invention relates to an electro-hydraulic actuator unit and a vehicle. Background Technology

[0002] Currently, there are various solutions for electro-hydraulic actuators in the automotive field. Due to the increasing number of control parameters and rising quality and safety requirements, the demand for innovative and robust electro-hydraulic actuator units is constantly growing.

[0003] The automotive industry's continuous efforts to reduce weight and lower fuel consumption, coupled with increasing competition, have created cost pressures, leading to a greater demand for cheaper and more efficient automotive parts. Summary of the Invention

[0004] The electro-hydraulic actuator unit according to the invention, having the features of claim 1, has the following advantages over known devices: if the valve unit of the electro-hydraulic actuator unit fails according to DIN EN ISO 13849, a safe state can be achieved through the design of the valve unit. Preferably, the safe state can be achieved by setting a predetermined pressure in the valve unit to prevent possible incorrect deflection of the actuator unit, etc.

[0005] According to the invention, this is achieved by the following: an electro-hydraulic actuator unit has a valve unit connected to a pump unit and an actuator unit, such that the valve unit at least partially controls the deflection of the actuator unit, wherein the valve unit is designed to control the flow of fluid via a valve spool to control the deflection of the actuator unit, wherein the valve unit is designed to place the actuator unit in a safe state if the pressure in the fluid, particularly due to a fault, increases beyond a predetermined limit, wherein in the safe state, a predetermined pressure is established in the fluid, particularly in a near-pressureless state.

[0006] In other words, this valve unit ensures that if the valve spool is blocked or misaligned, resulting in an increase in pressure within the valve unit, it will not lead to any incorrect control of the actuator unit. This is particularly guaranteed by the fact that, under safe conditions, a predetermined pressure can be set or maintained in the fluid regulated by the valve unit.

[0007] The dependent claims illustrate preferred improvements to the invention.

[0008] Preferably, under safe conditions, the pump unit provides fluid with increased pressure, and the pressure within the valve unit does not exceed a predetermined pressure.

[0009] The advantage of this implementation is that, although the pump unit or similar supply system still supplies fluid at increased pressure, the valve unit can maintain a lower pressure inside the valve unit. This ensures that the predetermined pressure is maintained under safe conditions.

[0010] More preferably, the safety condition, especially the unpressurized condition, meets the requirements of PL D according to DIN ENISO 13849.

[0011] The advantage of this implementation is that the electro-hydraulic actuator unit can be used in safety-related applications, especially those that meet the safety level PLD requirements.

[0012] More preferably, the pressure increase is caused by foreign matter in the valve unit.

[0013] More preferably, the pressure increase is caused by contaminated oil in the valve unit.

[0014] The advantage of this implementation is that the electro-hydraulic actuator unit can still establish a safe state even if the oil used may contain contaminants due to improper use.

[0015] More preferably, the foreign object can at least partially block the valve spool, thereby exceeding a predetermined limit value, wherein the valve unit is configured to regulate a predetermined pressure when the predetermined limit value is exceeded.

[0016] The advantage of this implementation is that, for example, foreign objects can wedge between the opening of the valve spool and the orifice of the valve unit, thereby at least partially preventing the deflection of the valve spool. In this blocked position, fluid with increased pressure, for example, from the pump unit, can continuously flow into the valve unit because the valve spool is blocked. However, preferably, if a limit value is exceeded, the valve unit can still return to a safe state.

[0017] More preferably, the valve unit has a first recess connected to the pump unit, wherein the valve spool is designed to at least partially close the first recess, and the offset between the first recess and the orifice in the valve spool causes an increase in pressure. An advantage of this embodiment is that if deflection of the valve spool causes the first recess to not close completely, the pressure within the valve unit will continue to rise because the pump unit will continue to pump fluid into the valve unit at the increased pressure. However, the valve unit can initiate a safety state from a predetermined limit value, preventing deflection of the actuator unit or similar device.

[0018] More preferably, the valve unit is configured to discharge fluid from the valve unit when a predetermined limit value is exceeded, so as to set a predetermined pressure.

[0019] The advantage of this implementation is that the fluid does not enter the environment, but is discharged in a targeted manner, such as into a tank unit.

[0020] More preferably, the valve unit is configured to open the valve unit's closing mechanism to set a predetermined pressure.

[0021] The advantage of this implementation is that the valve unit can, for example, have a closing mechanism, such as a spring ball located in an opening that defines a predetermined limit value. When the predetermined limit value is reached, the ball moves out of the opening to allow fluid to drain from the valve unit, thereby setting a predetermined pressure.

[0022] Preferably, the valve unit is configured to reduce the first pressure of the fluid at the first recess to a second pressure at the valve outlet.

[0023] The advantage of this implementation is that the valve unit can not only control the fluid flow rate, but also reduce the pressure.

[0024] Preferably, the valve unit has a second recess that can be connected to the tank unit, wherein the valve unit is configured to discharge fluid into the tank unit when a predetermined limit value is exceeded, so as to set a predetermined pressure.

[0025] The advantage of this implementation is that the fluid lines can be specifically adjusted to avoid overpressure and flow resistance or similar issues.

[0026] Another aspect of the invention relates to a vehicle having an electro-hydraulic actuator unit as described above and below. Attached Figure Description

[0027] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings:

[0028] Figure 1 An electro-hydraulic actuator unit according to one embodiment is shown;

[0029] Figure 2 A vehicle according to one embodiment is shown. Detailed Implementation

[0030] Preferably, all identical elements, units, and / or steps in all figures have the same reference numerals.

[0031] Figure 1 An electro-hydraulic actuator unit 10 according to one embodiment is shown. The electro-hydraulic actuator unit 10 has an actuator unit 12 and a valve unit 14, wherein the electro-hydraulic actuator unit 10 is connected to a pump unit 16 and the actuator unit 12 such that the valve unit 14 at least partially controls the deflection of the actuator unit 12, wherein the valve unit 14 is designed to control the flow of fluid via a valve spool 18 to control the deflection of the actuator unit 10, wherein the valve unit 14 is designed to place the valve unit 14 into a safe state if the pressure in the fluid, particularly due to a fault, increases beyond a predetermined limit value, wherein in the safe state, a predetermined pressure is established in the fluid.

[0032] like Figure 1 As shown, the valve core 18 is disposed within the valve unit 14. Preferably, the valve core 18 has an opening 20, which is part of the closing mechanism 26. When the pressure within the valve core 18 or the valve unit 14 rises above a predetermined limit value, the closing mechanism 26 opens to allow fluid to be discharged into the tank unit 30 through the second recess 28. This ensures a predetermined pressure of the fluid at the valve outlet 32 ​​under safe conditions. More preferably, the valve unit has a first recess 22, wherein the valve core 18 has a hole 24 offset from the recess 22, which can be used to secure correctly installed components. More preferably, the valve unit 14 can reduce the first pressure in the fluid in the first recess 22 to a second pressure at the valve outlet 32.

[0033] Figure 2 A vehicle 100 with an electro-hydraulic actuator unit 10 is shown.

[0034] List of reference numerals

[0035] 10 Electro-hydraulic actuator units

[0036] 14 Valve Units

[0037] 16 Pump Units

[0038] 18 Valve Core

[0039] 20 Opening

[0040] 22 First recess

[0041] 24 holes

[0042] 26 Closing Institutions

[0043] 28 Second recess

[0044] 30 tank units

[0045] 32 Valve Outlet

[0046] 100 vehicles

Claims

1. An electro-hydraulic actuator unit (10), comprising: Valve unit (14), The electro-hydraulic actuator unit (10) is connected to the pump unit (16) and the actuator unit (12) such that the valve unit (14) at least partially controls the deflection of the actuator unit (12), wherein the valve unit (14) is designed to control the flow of fluid via the valve core (18) of the valve unit (14) in order to control the deflection of the actuator unit (12), wherein the valve unit (14) is designed to place the actuator unit (12) in a safe state if the pressure in the fluid, particularly due to a fault, increases beyond a predetermined limit, wherein in the safe state, a predetermined pressure is established in the fluid, particularly in a state of near-no pressure.

2. The electro-hydraulic actuator unit (10) according to claim 1, wherein, In a safe state, the pump unit (16) provides fluid with increased pressure, and the pressure in the valve unit (14) does not exceed a predetermined pressure.

3. The electro-hydraulic actuator unit (10) according to any one of the preceding claims, wherein, The safety condition, especially the unpressurized condition, meets the requirements of PL D according to DIN EN ISO 13849.

4. The electro-hydraulic actuator unit (10) according to any of the preceding claims, wherein the pressure increase is caused by foreign matter in the valve unit (14).

5. The electro-hydraulic actuator unit (10) according to claim 4, wherein, Foreign matter at least partially blocks the valve core (18) to exceed a predetermined limit value, wherein the valve unit (14) is configured to regulate a predetermined pressure when the predetermined limit value is exceeded.

6. The electro-hydraulic actuator unit (10) according to any one of the preceding claims, wherein, The valve unit (14) has a first recess (22) connected via the pump unit (16), wherein the valve core (18) is designed to at least partially close the first recess, wherein the offset between the first recess (22) and the hole (24) in the valve core (18) results in an increase in pressure.

7. The electro-hydraulic actuator unit (10) according to claim 6, wherein, The valve unit (14) is configured to discharge fluid from the valve unit (14) when the predetermined limit value is exceeded, so as to set the predetermined pressure.

8. The electro-hydraulic actuator unit (10) according to any one of the preceding claims, wherein, The valve unit (14) is configured to open the closing mechanism (26) of the valve unit (14) in order to set the predetermined pressure.

9. The electro-hydraulic actuator unit (10) according to any one of the preceding claims, wherein, The valve unit (14) is configured to reduce the first pressure of the fluid at the first recess (22) to a second pressure at the valve outlet (32).

10. The electro-hydraulic actuator unit (10) according to any one of the preceding claims, wherein, The valve unit (14) has a second recess (28) that can be connected to the tank unit (30), wherein the valve unit (14) is configured to discharge fluid into the tank unit (30) when a predetermined limit value is exceeded, so as to set a predetermined pressure.

11. A vehicle (100) comprising an electro-hydraulic actuator unit (10) according to any one of the preceding claims.

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