Pressure generating device and operating method comprising an electrically driven dual-action reciprocating piston

Patent metadata

Field	Value
Publication number	US-11097708-B2
Application number	US-201615558385-A
Country	US
Kind code	B2
Filing date	Mar 16, 2016
Priority date	Mar 16, 2015
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A pressure generating device may comprise a piston-cylinder unit having a bilaterally acting piston with two effective surfaces defining two respective, separate working spaces in a sealing manner. Each working space is connected via a hydraulic line to a hydraulic circuit, wherein at least one hydraulic chamber of a consumer is connected to each hydraulic circuit, and wherein a drive drives the piston. Each working space may be in communication with a reservoir for hydraulic medium, via a respective hydraulic line having a respective switching valve. Alternatively, one or both working spaces may be in communication with a reservoir for hydraulic medium via a hydraulic line, with a switching valve in one or both hydraulic lines, and/or a respective outlet valve may be associated with one or more hydraulic chambers of the consumer, and a further connecting line having a switching valve may connect the pressure chambers and/or hydraulic lines.

First claim

What is claimed is:

1. A pressure generating device comprising:
a piston-cylinder unit, which comprises a bilaterally acting piston that separates two working spaces in the cylinder of the piston-cylinder unit from one another in a sealing manner, wherein the piston has two surfaces, and wherein each surface of the piston respectively defines a respective one of the two working spaces,
respective first hydraulic lines connecting each of the respective working spaces to a respective hydraulic circuit, there thus being two respective hydraulic circuits corresponding to the two respective working spaces, wherein at least one hydraulic chamber of a respective hydraulic consumer is connected to a respective one of the two hydraulic circuits, and
a drive configured to drive the piston of the piston-cylinder unit, wherein
each working space is in communication by means of a respective second hydraulic line with a reservoir vessel for a hydraulic medium, wherein in each respective second hydraulic line connecting a respective working space with the reservoir vessel, at least one switching valve is arranged for the optional closure or opening of the respective second hydraulic line,
wherein the pressure generating device further comprises at least one pressure sensor configured to measure a pressure in at least one of the first hydraulic lines,
wherein pressure reduction in at least one of the hydraulic consumers is carried out by opening at least one switching valve, wherein with the respectively opened switching valve, the hydraulic medium for the pressure reduction in one or more of the hydraulic consumers is enabled to be released or to flow out, via at least one of the respective working spaces, into the reservoir vessel, wherein a control device uses, for regulation, pressure calculated by one or more pressure sensors in one or both hydraulic circuits and/or calculated from a phase current sensor.

2. The pressure generating device according to claim 1 , wherein the drive of the piston-cylinder unit includes a linear motor or a rotation motor and gear mechanism.

3. The pressure generating device according to claim 1 , wherein only a front one of the working spaces, defined by one of the effective surfaces of the piston that is a leading surface of the piston when the piston is moved in a forward stroke, is configured to be connected via a valve to the reservoir vessel, or wherein both working spaces are configured to be connected via valves to the reservoir vessel.

4. The pressure generating device according to claim 1 , wherein areas of the effective surfaces are in a ratio of 1.5:1 to 2.5:1 to one another.

5. The pressure generating device according to claim 1 , wherein the working spaces and/or the hydraulic lines connecting the working spaces to the hydraulic circuits, or the hydraulic circuits, are connected to one another via a connecting line, wherein at least one switching valve is arranged in the connecting line for optional opening or closure of the connecting line.

6. The pressure generating device according to claim 5 , wherein the at least one switching valve has a flow cross-section sufficiently large to avoid a throttling function.

7. The pressure generating device according to claim 5 , wherein the connecting line and a first one of the hydraulic lines connecting a respective working space of the piston-cylinder unit to a respective brake circuit meet at a point (P 1 ), wherein a switching valve is arranged in a section of the first one of the hydraulic lines that connects the point P 1 and the working space, and wherein the connecting line and the second one of the hydraulic lines connecting a respective working space of the piston-cylinder unit to a respective brake circuit meet at a point (P 2 ), wherein a further switching valve is arranged in a section of the second one of the hydraulic lines leading from the point P 2 to the at least one hydraulic consumer.

8. The pressure generating device according to claim 1 , wherein both working spaces are connected to the reservoir vessel, wherein the connection is formed via non-return valves with a closing direction from the respective working spaces of the pressure generating device to the reservoir vessel or via switching valves.

9. The pressure generating device according to claim 1 , further comprising a pressure sensor that is used only in one of the hydraulic circuits, and wherein a pressure of a respective one of the surfaces of the piston defining a respective one of the working spaces is calculated via a phase current of the drive measured with one of more current sensors and a torque calculated based on a torque constant, taking into account a switching state of connecting valve, and a transmission efficiency, and used for pressure regulation.

10. The pressure generating device according to claim 1 , wherein no pressure sensor is used in either one of the hydraulic circuits, and wherein a pressure of a respective one of the surfaces of the piston defining a respective one of the working spaces is calculated via a phase current of the drive measured with redundant current sensors and a torque calculated based on a torque constant, taking into account a switching state of s connecting valve, and a transmission efficiency, and used for pressure regulation.

11. The pressure generating device according to claim 1 , further comprising a respective switching valve associated with a respective hydraulically acting working chamber of the one or more hydraulic consumers for optional closure or opening of a respective hydraulic line to the pressure generating device.

12. The pressure generating device according to claim 1 , wherein pressure build-up and pressure reduction are carried out by means of path control of the bilaterally acting piston.

13. The pressure generating device according to claim 12 , wherein the path control of the double-stroke piston is carried out by means of an angular position of a rotation motor of the drive, or stroke position of a linear motor of the drive, or a position of the bilaterally acting piston.

14. The pressure generating device according to claim 1 , wherein pressure build-up and pressure reduction in one or both hydraulic lines connecting the working spaces of the piston-cylinder unit to the hydraulic circuits is enabled to be altered by opening and closing the switching valve in the connecting line.

15. The pressure generating device according to claim 14 , wherein, with a simultaneous pressure reduction in a first one of the two hydraulic circuits and pressure build-up in the second one of the two hydraulic circuits, the control device is configured to use the pressure calculated by the one or more pressure sensors in one or both of the hydraulic circuits and/or calculated from the phase current sensor.

16. The pressure generating device according to claim 1 , wherein, by means of adjustment of the piston, pressure is increased or reduced in at least one hydraulic consumer and is reduced in at least one other hydraulic consumer.

17. The pressure generating device according to claim 1 , wherein pressure supply of at least two hydraulic consumers in multiplex operation (MUX), is effected by disconnecting the hydraulic consumers by means of associated valves.

18. The pressure generating device according to claim 1 , wherein the pressure generating device is configured to supply at least two hydraulic consumers with pressure, wherein one hydraulic consumer is a vehicle clutch, a chamber of a change speed selector or a gear mechanism.

19. The pressure gene

Assignees

• Ipgate Ag

Inventors

• Leiber Heinz
• Leiber Thomas
• Köglsperger Christian

Classifications

• B60T13/745

  acting on a hydraulic system, e.g. a master cylinder · CPC title

• B60T13/686 Primary

  in hydraulic systems or parts thereof · CPC title

• B60T8/4081 Primary

  Systems with stroke simulating devices for driver input (B60T8/4077 takes precedence) · CPC title

• B60T8/326

  Hydraulic systems · CPC title

• B60T7/042

  by electrical means, e.g. using travel or force sensors · CPC title