Device and method for maintaining a produced hydraulic pressure

Abstract

The invention relates to a device (100) for maintaining a hydraulic pressure (p), which can be set by a pressure generator (50). Said device comprises an inlet (110) for coupling to the pressure generator (50); an outlet (120) for providing the hydraulic pressure (p); at least one first check valve (131) and a switching apparatus (140) between the inlet (110) and the outlet (120). The first checkvalve (131) is designed to open a flow path from the inlet (110) to the outlet (120) when a first opening pressure (p1) is exceeded and to prevent flow in the opposite direction. The switching apparatus (140) is designed to hold the hydraulic pressure (p) at the outlet (120) if a pressure (p0) produced by the pressure generator (50) is greater than a switching pressure (pS) and to reduce the hydraulic pressure (p) at the outlet (120) if a pressure (p0) produced by the pressure generator (50) is less than the switching pressure (pS), wherein the switching pressure (pS) is less than the first opening pressure (p1).

Description

technical field [0001] The present invention relates to a device and a method for maintaining a generated hydraulic pressure, and in particular to a hydraulic proportional valve for a steering control device and an electrically driven hydraulic servo steering device. Background technique [0002] In conventional hydrostatic actuating drives for steering gear control, there are two problems that have not yet been adequately resolved. One problem relates to maintaining high pressure loads, such as occur during continuous loading. A second problem concerns significant steering resistance in the event of system failure, in conventional systems the driver has to exert force in order to steer the vehicle. [0003] Figure 8 A conventional system is shown as an example, in which the steering gear 90 is operated hydraulically. Hydraulic pressure is generated by a pressure generator 50 with a motor 51 , eg a pump. The steering gear 90 has two working cylinders 91 , 92 which are se...

AI Technical Summary

Problems solved by technology

One problem relates to maintaining high pressure loads, such as occur during continuous load

The second problem involves significant steering resistance in the event of system failure, in conventional systems the driver has to exert force in order to steer the vehicle

This results in a permanent continuous load on the motor or pump, which impairs reliability and increases wear

[0005] The second problem above arises in the event of a system failure, for example when the pump is unable to provide steering assistance due to an electrical failure

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