DE102012215879A1 - Hydraulic steered storage chamber valve for use in hydraulic vehicle brake system, has plunger that reaches through feedthrough and closing element and feedthrough provided with cross-section, in which valve seat is equipped - Google Patents

Abstract

The hydraulic steered storage chamber valve (10) has a pressure spring (15.1) that is linked up with a closing element (12.1). A feedthrough (12.4) is provided with a cross-section (Q1), in which a valve seat (12.3) is included. A piston feather (16.1) pushes the closing element from the valve seat. A plunger (22) reaches through another feedthrough (14.2) and another closing element (12.2). The former cross-section is smaller than another cross-section (Q2). A thin end section (18.2) of the plunger reaches through the former feedthrough and the former closing element. An independent claim is included for a hydraulic vehicle brake system with a master brake cylinder.

Description

State of the art

The invention relates to a hydraulically controlled storage chamber valve according to the preamble of independent claim 1 and of a hydraulic vehicle brake system according to the preamble of independent claim 10.

Hydraulic control valves are known from the prior art, which take over in a hydraulic vehicle brake system, which has an ABS / ESP functionality (ABS: Antilock Braking, ESP: Electronic Stability Program), the task of a hydraulic suction valve and in addition a return pump before elevated pressure on the Can protect suction side.

From the patent US 7,543,896 B2 For example, a hydraulically controlled storage chamber valve is known in which a spring-loaded ball seat valve is opened via a plunger in the accumulator piston. This is done at a specified for the system balance of power between spring biasing force and hydraulically effective force. The actuation of the ball seat valve via a cylindrical metallic plunger, which is pressed into the accumulator piston. The accumulator piston also receives a sealing ring and a guide ring. Between the accumulator piston and the closure lid, which is connected via a Halteverstemmung with the pump housing, there is a correspondingly biased compression spring. The spring force acts against the hydraulically acting force on the accumulator piston and, in the event of an excess of the spring force, causes the accumulator piston-tappet combination to be displaced in the opening direction of the accumulator chamber valve. The ball is moved by the plunger from the seat and opened the storage chamber valve.

In the published patent application DE 42 02 388 A1 For example, a hydraulic brake system for a motor vehicle is described. The brake system described comprises a hydraulically controlled storage chamber valve with a biased by a first compression spring closing element which seals a valve seat in a valve body, and a plunger which is connected to a loaded by a second compression spring accumulator piston and the closing element presses out of the valve seat, if between the spring biasing forces and a hydraulically effective force is a specified balance of forces. In these constructions of storage chamber valves, the sealing body of the spring-assisted closed valve is moved into the open position by a pin connected to the accumulator piston as soon as the accumulator chamber volume falls below a threshold value, ie the accumulator piston approaches the stop.

Disclosure of the invention

The hydraulically controlled storage chamber valve according to the invention with the features of independent claim 1 has the advantage that both a large flow and a safe opening of the valve are ensured at high pressures.

The essence of the invention consists in a two-stage design of the check valve. If there is a high differential pressure at the check valve, the first stage of the check valve can be opened via a plunger with a smaller diameter moved by the accumulator piston. The force for opening a small flow cross section is smaller due to the effective smaller cross section of the first closing element, so that can be opened against a high back pressure. If there is a high back pressure, then no large open cross-section is required because enough fluid can get to the return pump on the applied pressure difference. If then the back pressure drops, then the larger cross section of the check valve for the fluid flow in the second stage can be opened.

Embodiments of the present invention provide a hydraulically controlled accumulator chamber valve which includes a first closure element biased by a first compression spring sealing a first passage having a first cross section in a first valve seat and a plunger passing through the first passageway and one of a piston spring acted upon the accumulator piston is movable and the first closing element presses out of the valve seat and the first passage opens when there is a specified balance of forces between the spring biasing forces and a hydraulically active force. According to the invention, the first feedthrough and the first valve seat are introduced into a second closing element pretensioned via a second compression spring, which seals a second feedthrough with a second cross section in a second valve seat, wherein the pushrod engages through the second feedthrough and the second closing element after the first closing element presses the second valve seat and opens the second passage when there is a specified balance of forces between the spring biasing forces and the hydraulically-acting force, the first cross-section being smaller than the second cross-section.

Furthermore, a hydraulic vehicle brake system with a master cylinder, a fluid control unit and at least one wheel brake proposed, wherein the fluid control unit for brake pressure modulation of at least one wheel brake in at least one brake circuit each comprise a switching valve, at least one inlet valve, at least one outlet valve and designed as a hydraulically controlled storage chamber valve according to the invention shut-off valve and a return pump. Here, the shut-off valve is looped in a suction line between the corresponding return pump and the master cylinder.

The measures and refinements recited in the dependent claims advantageous improvements of the independent claim 1 hydraulically controlled storage chamber valve are possible.

It is particularly advantageous that the plunger can have a shoulder, which divides the plunger into two sections with different diameters. A thinner end portion of the plunger may pass through the first passage and act on the first closure member, and a thicker base portion of the plunger may pass through the second passage and act on the second closure member via the shoulder. This advantageously allows a simple implementation of the two-stage design of the storage chamber valve. The length of the end portion is selected so that first the first closing element is pressed out of the first valve seat before the shoulder of the plunger rests against the second closing element and pushes it out of the second valve seat.

In an advantageous embodiment of the hydraulically controlled storage chamber valve according to the invention, the first valve seat can be introduced as a hollow truncated cone at a first edge of the first passage in the second closing element.

In a further advantageous embodiment of the hydraulically controlled storage chamber valve according to the invention, a discharge groove can be introduced at a second edge of the first passage in the second closing element. The Abströmnut advantageously prevents the shoulder on the plunger closes the first passage when the plunger acts on the paragraph on the second closing element.

In a further advantageous embodiment of the hydraulically controlled storage chamber valve according to the invention, the second valve seat can be designed, for example, as a flat sealing seat on the edge of the second feedthrough.

In a further advantageous embodiment of the hydraulically controlled storage chamber valve according to the invention, the second closing element can be designed, for example, as a plastic part or metal part.

In a further advantageous embodiment of the hydraulically controlled storage chamber valve according to the invention, the first compression spring can be supported on the first closing element and on a guide nose, which is arranged on the bottom of a guide sleeve. The second compression spring may be supported, for example, on the second closing element and on the bottom of the guide sleeve. The guide sleeve can for example also be designed as a plastic part or metal part.

An embodiment of the invention is illustrated in the drawings and will be explained in more detail in the following description. In the drawings, like reference numerals designate components that perform the same or analog functions.

Brief description of the drawings

1 shows a schematic diagram of an embodiment of a brake circuit for a hydraulic vehicle brake system with an embodiment of a storage chamber valve according to the invention.

2 shows a schematic detail of a section of the brake circuit with the storage chamber valve according to the invention 1 ,

3 shows a schematic sectional view of an embodiment of a storage chamber valve according to the invention for the hydraulic vehicle brake system 1 ,

Embodiments of the invention

How out 1 and 2 can be seen, includes the illustrated embodiment of a vehicle brake system according to the invention 1 a brake unit 3 with a brake pedal 3.1 , a brake booster 3.2 , a master cylinder 03.03 and a storage container 3.4 a fluid control unit having at least two brake circuits, one of which is shown, and at least one wheel brake R1, R2 on each wheel. For brake pressure modulation of the at least one wheel brake R1, R2 in the corresponding brake circuit, the fluid control unit comprises a switching valve UV and a return pump RP with a drive A, and for each wheel R1, R2 an inlet valve EV1, EV2 and an outlet valve AV1, AV2. Furthermore, the fluid control unit comprises a plurality of check valves and a shut-off valve 10 , which in a suction line between the corresponding return pump RP and the master cylinder 03.03 is looped. The shut-off valve is a hydraulically controlled storage chamber valve 10 executed and includes a check valve 12 and a storage chamber 9 , Here is the check valve 12 via a first fluid connection 7.1 with the master cylinder 03.03 connected. A second fluid connection 9.1 connects the storage chamber 9 with a suction connection of the return pump RP. One through a storage piston 16 from the storage chamber 9 separate compensation room 9.3 is via a balancing connection 9.4 connected to the atmosphere.

3 shows a valve arrangement with the hydraulically controlled storage chamber valve according to the invention 10 , which in a stepped receiving bore 7 a fluid block 5 or pump housing is arranged. At the stepped receiving bore 7 the storage chamber closes 9 in which of a piston spring 16.1 loaded storage piston 16 is movably guided.

How out 2 and 3 can be further seen, includes the illustrated embodiment of the hydraulically controlled storage chamber valve 10 a via a first compression spring 15.1 preloaded first closing element 12.1 , which is a first implementation 12.4 with a first cross-section Q1 in a first valve seat 12.3 seals, and a pestle 18 which is the first implementation 12.4 engages and of the piston spring 16.1 acted on storage piston 16 is movable and the first closing element 12.1 from the valve seat 12.3 presses and the first execution 12.4 opens when there is a specified balance of forces between the spring biasing forces and a hydraulically-acting force. According to the invention, the first implementation 12.4 and the first valve seat 12.3 in a via a second compression spring 15.2 preloaded second closing element 12.2 introduced, which is a second implementation 14.2 with a second cross-section Q2 in a second valve seat 14.1 seals. Here, the plunger passes through 22 the second implementation 14.2 and pushes the second closing element 12.2 after the first closing element 12.1 from the second valve seat 14.1 and opens the second execution 14.2 when there is a specified balance of forces between the spring biasing forces and the hydraulically-acting force, the first cross-section Q1 of the first pass 12.4 smaller than the second cross section Q2 of the second passage 14.2 is.

How out 3 can be further seen, the plunger 18 a paragraph 18.1 on which the plunger 18 divided into two sections with different diameters. Here, a thinner end section passes through 18.2 of the plunger 18 the first implementation 12.4 and acts on the first closing element 12.1 , A thicker base section 18.3 of the plunger 18 is with the storage piston 16 connected and passes through the second implementation 14.2 and works over the paragraph 18.1 on the second closing element 12.2 , The first valve seat 12.3 is as a hollow truncated cone at a first edge of the first implementation 12.4 in the second closing element 12.2 brought in. At a second edge of the first execution 12.4 is a discharge groove 12.5 in the second closing element 12.2 introduced to prevent the paragraph 18.1 of the plunger 18 the first implementation 12.4 closes. The second valve seat 14.1 is at an upper edge of the second passage 14.2 designed as a flat sealing seat. The second closing element 12.2 is preferably designed as a plastic part. But can also be made of other materials, such as steel or other metals.

How out 3 further, a hood-shaped guide sleeve 20 up to the stop of a protruding edge in the stepped receiving bore 7 introduced. Below the guide sleeve 20 is a valve body 14 into the receiving hole 7 pressed. In the valve body 14 is the second implementation 14.2 introduced, at the upper edge of the second valve seat 14.1 is arranged. The first compression spring 15.1 rests on the first closing element 12.1 and on a guide nose 24 off, which on the ground 22 the guide sleeve 20 is arranged. The second compression spring 15.1 is supported on the second closing element 12.2 and on the ground 22 the guide sleeve 20 from. In addition, the guide sleeve has inlet openings 26 on which an unillustrated filter can be arranged to filter dirt particles from the fluid.

In the illustrated embodiments, the spring-loaded accumulator piston presses 16 over the pestle 18 the first closing element 12.1 , which is designed for example as a closing ball, from the first valve seat 12.3 when the on the accumulator piston 16 acting spring force of the piston spring 16.1 larger than the on the storage piston 16 acting hydraulic force and the on the first closing element 12.1 acting biasing force of the first compression spring 15.1 is. Is that on the storage piston 16 acting spring force of the piston spring 16.1 smaller than the one on the accumulator piston 16 acting hydraulic force and the on the first closing element 12.1 acting biasing force of the first compression spring 15.1 , then becomes the first closing element 12.1 in the first valve seat 12.3 pressed. If the movable in the storage chamber 9 guided accumulator piston 16 , which has a piston seal 16.2 against a wall 9.2 the storage chamber 9 seals and the storage chamber 9 from the equalization room 9.3 separates, the first closing element 12.1 from the first valve seat 12.3 pushes, then a fluid connection from the master cylinder 03.03 opened to the return pump RP. In this position, the Return pump RP in ESP case from the reservoir 3.4 of the master cylinder 03.03 suck. Will the storage chamber 9 filled in the ABS / ESP case during the scheme, then the spring-loaded accumulator piston 16 pushed back and the check valve 12 closes. That means that the first closing element 12.1 at the first valve seat 12.3 sealingly abuts, and the second closing element 12.2 at the second valve seat 14.1 sealingly rests. With closed check valve 12 can no further pressure on the master cylinder even when the brake is applied 03.03 in the storage chamber 9 be pressed. This prevents an increased pressure from entering the suction side of the return pump RP and loading the suction-side seal of the return pump RP. This is particularly important when using a gear pump, which is sealed on the suction side with a shaft seal. A pressurized shaft seal has a reduced life and high loss friction. As a rule, the storage chamber 9 has been sucked empty via the return pump RP, the connection to the master cylinder must 03.03 be restored, even if over the master cylinder 03.03 still pressure on the check valve 12 pending. The check valve 12 is designed so that the spring force of the piston spring 16.1 on the storage piston 16 sufficient to the check valve 12 to open. On the other hand, the flow through the check valve should be 12 if possible be so large that in front of the return pump RP through the throttle point on the check valve 12 no negative pressure is created.

This is due to the two-stage design of the check valve 12 reached. If a high differential pressure at the check valve 12 rests on the small cross-section of the end section 18.2 of the plunger 18 and the smaller first section Q1 of the first pass 12.4 the first stage of the check valve 12 be opened. The force for opening the smaller flow cross section Q1 is due to the cross section of the first closing element 12.1 small, so that can be opened against a high back pressure. If a high back pressure is applied, no large open cross-section is required, because on the applied pressure difference enough fluid reaches the return pump RP. If then the back pressure drops off, the large cross section Q2 of the second passage 14.2 be opened in the second stage. When the second stage is opened, the larger cross-section Q2 is released, through which the return pump RP can suck the fluid.

Embodiments of the present invention provide a hydraulically controlled storage chamber valve which both ensures high flow and ensures safe opening at high pressures.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 7543896 B2 [0003]
• DE 4202388 A1 [0004]

Claims (10)

Hydraulically controlled storage chamber valve with a via a first compression spring ( 15.1 ) preloaded first closing element ( 12.1 ), which is a first implementation ( 12.4 ) having a first cross section (Q1) in a first valve seat ( 12.3 ), and a pestle ( 18 ), which is the first implementation ( 12.4 ) and by one of a piston spring ( 16.1 ) acted upon storage piston ( 16 ) is movable and the first closing element ( 12.1 ) from the valve seat ( 12.3 ) and the first execution ( 12.4 ) opens when there is a specified balance of forces between the spring biasing forces and a hydraulically-acting force, characterized in that the first passage ( 12.4 ) and the first valve seat ( 12.3 ) in a via a second compression spring ( 15.2 ) biased second closing element ( 12.2 ), which is a second implementation ( 14.2 ) with a second cross-section (Q2) in a second valve seat ( 14.1 ), the ram ( 22 ) the second implementation ( 14.2 ) and the second closing element ( 12.2 ) after the first closing element ( 12.1 ) from the second valve seat ( 14.1 ) and the second execution ( 14.2 ) opens when there is a specified balance of forces between the spring biasing forces and the hydraulically-acting force, the first cross-section (Q1) being smaller than the second cross-section (Q2). Storage chamber valve according to claim 1, characterized in that the plunger ( 18 ) a paragraph ( 18.1 ), which the plunger ( 18 ) is divided into two sections of different diameters. Storage chamber valve according to claim 2, characterized in that a thinner end section ( 18.2 ) of the plunger ( 18 ) the first implementation ( 12.4 ) and on the first closing element ( 12.1 ), and a thicker base section ( 18.3 ) of the plunger ( 18 ) the second implementation ( 14.2 ) and via the paragraph ( 18.1 ) on the second closing element ( 12.2 ) acts. Storage chamber valve according to one of claims 1 to 3, characterized in that the first valve seat ( 12.3 ) at a first edge of the first execution ( 12.4 ) as a hollow truncated cone in the second closing element ( 12.2 ) is introduced. Storage chamber valve according to one of claims 1 to 4, characterized in that an outflow groove ( 12.5 ) at a second edge of the first implementation ( 12.4 ) in the second closing element ( 12.2 ) is introduced. Storage chamber valve according to one of claims 1 to 5, characterized in that the second valve seat ( 14.1 ) at the edge of the second implementation ( 14.2 ) is designed as a flat sealing seat. Storage chamber valve according to one of claims 1 to 6, characterized in that the second closing element ( 12.2 ) is designed as a plastic part or metal part. Storage chamber valve according to one of claims 1 to 7, characterized in that the first compression spring ( 15.1 ) on the first closing element ( 12.1 ) and on a guide nose ( 24 ) supported on the ground ( 22 ) a guide sleeve ( 20 ) is arranged. Storage chamber valve according to one of claims 1 to 8, characterized in that the second compression spring ( 15.1 ) on the second closing element ( 12.2 ) and on the ground ( 22 ) of the guide sleeve ( 20 ) is supported. Hydraulic vehicle brake system with a master cylinder ( 03.03 ), a fluid control unit and at least one wheel brake ( 5.1 ), wherein the fluid control unit for braking pressure modulation of the at least one wheel brake ( 5.1 ) in at least one brake circuit in each case a switching valve ( 4.1 ), at least one inlet valve (EV1, EV2), at least one outlet valve (AV1, AV2), a shut-off valve ( 10 ) and a return pump (RP), characterized in that the shut-off valve as hydraulically controlled storage chamber valve ( 10 ) is executed according to one of claims 1 to 9 and in a suction line between the corresponding return pump (RP) and the master cylinder ( 03.03 ) is looped.

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