DE102021108617B4 - 3/2 way valve concept - Google Patents

Abstract

Hydraulic actuation system for a hydraulic system comprising: - at least two hydraulic circuits (BK1, BK2), each with at least one hydraulic consumer, - at least one pressure generating device (DV) for pressure control or regulation, in the at least one hydraulic circuit (BK1, BK2), thereby characterized in that the pressure generating device (DZ) can be connected to either one or the other hydraulic circuit (BK1, BK2) by means of a controlled 3/2-way valve (MV).

Description

The present invention relates to a hydraulic actuation system for a hydraulic system, in particular in the form of a brake system, with at least one hydraulic circuit with at least one hydraulic consumer, in particular in the form of a hydraulically operated wheel brake, and at least one pressure generating device for pressure control or regulation, in particular for building up pressure and /or pressure reduction in the at least one hydraulic circuit.

State of the art

3/2-way solenoid valves are widely used in hydraulic drives and especially in automotive braking systems. In brake systems, 2/2-way solenoid valves are mostly used for pressure control and regulation. 3/2-way solenoid valves, on the other hand, are usually used to switch individual components of the brake system on and off. So revealed DE 10 2017 000 472 A1 the use of 3/2-way solenoid valves to connect the brake circuits either to the motor-driven pressure supply device or the master brake cylinder. The use of 3/2-way valves, as shown in the DE 10 2017 000 472 A1 is known, but leads to problems if the valve seat fails or is leaky. For example, if the hydraulic connection from the master brake cylinder to the pressure supply device in the 3/2-way solenoid valve is defective, ie leaky, this disadvantageously leads to strong pedal reaction, which inevitably leads to the pressure supply device being switched off, which means that the brake booster is no longer available.

Task of the invention

The object of the present invention is to further develop the generic hydraulic actuation system in such a way that it requires fewer valves while at the same time providing greater safety and is inexpensive, small and lightweight.

Solution to the task

This object is achieved according to the invention with a hydraulic actuation system with the features according to claim 1. A 3/2-way valve according to the invention for a hydraulic actuation system according to claims 1 to 9 is claimed by means of claims 11 following.

The hydraulic actuation system according to the invention is advantageously characterized by the fact that a reliable pressure supply to two hydraulic circuits is possible with just one 3/2-way valve. Even if one brake circuit fails, a pressure supply can still be ensured in the still intact hydraulic circuit by switching the pressure supply device to the other hydraulic circuit using the 3/2-way valve.

The hydraulic actuation system according to the invention can be used advantageously for a wide variety of supply purposes. It is therefore possible to use a hydraulic actuation system for a braking system, steering system, for the adjustment of clutches and/or transmissions, in particular their gear actuators.

A plunger piston which is driven by an electric motor drive is advantageously used. It is also possible to use a double-stroke piston, which delivers both in the forward and in the return stroke, although additional valves are necessary for this. However, it is of course also possible to use a rotary pump for continuous delivery.

If the hydraulic actuation system according to the invention is used to supply pressure to a brake system, its master brake cylinder, in particular in the form of a single master brake cylinder, can be connected to a hydraulic circuit or brake circuit via a 2/2-way switching valve (isolating valve). It is also possible to also provide a path simulator, which is advantageously connected to the master brake cylinder by means of a 3/2-way valve, for example, whereby the 3/2-way valve simultaneously serves to separate or connect the master brake cylinder to the brake circuit .

In order to further increase the dynamics of the system, at least one outlet valve can be provided, via which hydraulic medium can be drained from at least one hydraulic circuit directly into a storage container to reduce pressure.

The hydraulic actuation system according to the invention is explained below with reference to figures, whereby it is used, for example, to supply pressure to a brake system. In addition, the 3/2-way valve that can be used advantageously for this purpose is explained in more detail.

• 1: erste mögliche Ausführungsform eines erfindungsgemäßen hydraulischen Betätigungssystems für ein Bremssystem mit einem 3/2-Wegeventil zur wahlweisen Verbindung der Druckversorgungseinrichtung mit einem der beiden Hydraulikkreise;
• 2a: schematische Darstellung einer möglichen Ausführungsform eines erfindungsgemäßen 3/2-Wegeventils für das erfindungsgemäße Betätigungssystem im ersten unbestromten Zustand;
• 2b: schematische Darstellung des 3/2-Wegeventils gemäß 2a im zweiten bestromten Zustand;

Show it:

• 1 : first possible embodiment of a hydraulic actuation system according to the invention for a brake system with a 3/2-way valve for selectively connecting the pressure supply device to one of the two hydraulic circuits;
• 2a : Schematic representation of a possible embodiment of a 3/2-way valve according to the invention for the actuation system according to the invention in the first de-energized state;
• 2 B : Schematic representation of the 3/2-way valve according to 2a in the second energized state;

The 1 shows a pressure supply device DV with a plunger PL, which is connected via a 3/2-way valve MV, either to the hydraulic line HL1 to the second brake circuit BK2 or to the hydraulic line HL2, which leads to the first brake circuit.

The single master brake cylinder SHZ is connected via a hydraulic line HL3 to the first brake circuit BK1, in which a 2/2-way valve FV is arranged for selectively opening and closing the hydraulic line HL3. Normally, the pressure supply DV is connected to the brake circuit BK2 and via the circuit isolating valve KTV to the brake circuit BK1 for pressure equalization.

If the brake circuit BK2 fails, e.g. due to a leaky wheel cylinder seal, the pressure supply DV would also fail without the 3/2-way valve connection of the 3/2-way valve MV. By switching the 3/2-way valve MV to the first brake circuit BK1, the pressure supply DV feeds the intact brake circuit BK1 in the aforementioned error case. This avoids a critical error effect, with a loss of braking effect of approx. 80% (residual braking effect approx. 0.2g) and a change in the pedal characteristics.

Optionally, a WS travel simulator can be connected to ensure pedal characteristics. This can either be connected to the connecting line between the master brake cylinder SHZ and valve FV via an additional 2/2-way valve (not shown). However, it is also possible to replace the valve FV with an in 1 The 3/2-way valve shown in dashed lines can be connected, which results in numerous advantages, in particular cost savings, lower weight, etc.

Optionally, at least one hydraulic circuit BK1/BK2 and/or consumers (not shown) can each or jointly be assigned an outlet valve AV, so that a pressure reduction p _down to the storage container VB is possible. This allows the dynamics of the system to be increased and, for example, a simultaneous pressure reduction via the respective outlet valve AV and/or pressure build-up or reduction in another consumer/hydraulic circuit.

The 2a shows a schematic representation of a possible embodiment of a 3/2-way valve MV according to the invention for the brake system according to the invention. The 3/2-way valve MV has an excitation winding 5 which is arranged around a magnet yoke 6, in which the magnet armature 4 can be adjusted in the axial direction to the bolt 7, 7a. At the left end of the magnet tanker 4 there is a stop element 4a, which is in the in 2 shown non-energized second switching state of the valve MV abuts the inner wall of the magnet yoke 6. At the right end of the connecting bolt 7, 7a, the valve closing body VSK is arranged, which is firmly connected to the connecting bolt end 7a. The valve closing body VSK works together with the first valve seat VS1, which can be part of the magnet yoke 6, and with the second valve seat VS2. The magnet yoke 6 forms a first valve chamber K1 in the area of the bolt section 7a, which is connected via a hydraulic channel to the first valve connection AN1 for connecting the brake circuit BK2.

The 3/2-way valve MV also has a second valve chamber K2, in which the valve spring VF is arranged and into which the second connection AN2 opens. A third valve chamber K3 is arranged between the two chambers K1 and K2 and is laterally delimited by the valve seats VS1 and VS2. In addition, the third valve connection AN3 opens into the third chamber K3. One brake circuit BK1 is connected to the first valve connection AN1 and the other second brake circuit BK2 is connected to the second valve connection AN2, whereas the pressure supply device DV is connected to the third valve connection AN3. In 2a The “not energized” state is shown. In this, the valve spring VF presses the valve closing body VSK against the first valve seat VS1, with the magnet armature 4 also being adjusted to the left, so that the pressure supply device is connected to the second brake circuit BK2.

The 2 B shows the "energized" state of the solenoid valve MV, in which the armature is adjusted to the right by the magnetic field of the excitation coil, as a result of which the valve closing body VSK is pressed to the right against the second valve seat VS2, whereby the pressure supply device DV is now connected to the first brake circuit BK1 is.

The dimensioning of the valve spring VF determines the opening pressure in the fallback level, e.g. if the first brake circuit fails.

The valve spring VF should be dimensioned so that the magnet armature 4 is safely reset and the valve closing body VSK is pressed securely and sealingly against the first valve seat VS1.

List of reference symbols:

1

pedal

3

Piston tappet

4

Magnetic anchor

4a

Stop of the magnet armature 4

5

exciter development

6

Magnetic yoke

7, 7a

bolt

7, 7a

bolt

AN1, AN2, AN3

Valve connections

BK1, BK2

first and second brake circuit

BP1, BP2

isolation valves

DV

Pressure supply device

F1, F2, F3

filter

FP

Power through hydraulic pressure

H

Stroke of the magnet armature

HLi

Hydraulic lines

HV1

first hydraulic connection

HV2

second hydraulic connection

K1, K2, K3

Valve chamber

MV

3/2-way valve

MV1

3/2-way valve

P.D

Isolation valve

R1, R2

Working spaces of the master brake cylinder

RF

Valve spring force

SHZ

Single master cylinder

VF

Valve spring

VS1

first valve seat

VS2

second valve seat

VSK

Valve closing body

WS

Path simulator

Claims (20)

Hydraulic actuation system for a hydraulic system having the following: - at least two hydraulic circuits (BK1, BK2), each with at least one hydraulic consumer, - at least one pressure generating device (DV) for pressure control or regulation, in the at least one hydraulic circuit (BK1, BK2), thereby characterized in that the pressure generating device (DZ) can be connected to either one or the other hydraulic circuit (BK1, BK2) by means of a controlled 3/2-way valve (MV). Hydraulic actuation system Claim 1 , characterized in that the two hydraulic circuits (BK1, BK2) are connected to one another via a hydraulic connecting line (HL1-2), which can be either shut off or opened by means of a circuit isolating valve (KTV). Hydraulic actuation system Claim 2 , characterized in that a further circuit isolation valve (KTVr) is arranged in series with the circuit isolation valve (KTV) in the hydraulic connecting line (HL1-2). Hydraulic actuation system according to one of the Claims 1 until 3 , characterized in that a redundant or partially redundant control device (ECU) is provided for controlling the components of the hydraulic actuation system. Hydraulic actuation system Claim 4 , characterized in that the redundant or partially redundant control device (ECU) is provided for controlling the isolation valve (KTV) of the hydraulic actuation system. Hydraulic actuation system according to one of the preceding claims, characterized in that the pressure generating device (DV) has an electric motor-driven piston or rotary pump. Hydraulic actuation system Claim 6 , characterized in that the electric motor driving the pressure generating device (DV) has a redundant multi-phase winding. Hydraulic actuation system according to one of the preceding claims, characterized in that the hydraulic actuation system is a braking system. Hydraulic actuation system according to one of the preceding claims, characterized in that the at least one hydraulic Consumer is a hydraulically operated wheel brake. Hydraulic actuation system according to one of the preceding claims, characterized in that the at least one pressure generating device (DV) is used to build up pressure (p _up ) and/or reduce pressure (p _down ) in the at least one hydraulic circuit (BK1, BK2). Brake system with a hydraulic actuation system according to one of the preceding claims, with at least one brake circuit (BK1, BK2) in which at least one hydraulically acting wheel brake is arranged. 3/2-way valve (MV) for a hydraulic actuation system or for a brake system according to one of the preceding claims, characterized in that the 3/2-way valve (MV) has two valve seats (VS1, VS2), each of which can be closed by a valve closing body (VSK), the valve closing body (VSK) being connected to a magnet armature (4). 3/2-way valve (MV). Claim 12 , characterized in that the valve closing body (VSK) is arranged in a valve chamber (K3), the valve seats (VS1, VS2) being annular with conical valve seat surfaces, with the third valve chamber between the first and second valve chambers (K1, K2). (K3) is arranged, and in a second position of the magnet armature (4) this presses the valve closing body (VSK) sealingly against the second valve seat (VS2) and thus the first hydraulic connection (HV1) from the first valve chamber (K1) to the third Valve chamber (K3) opens and the second hydraulic connection between the second valve chamber (K2) to the third valve chamber (K3) is closed. 3/2-way valve (MV). Claim 13 , characterized in that the second position of the magnet armature (4) is achieved by energizing the excitation coil (5) of the 3/2-way valve (MV). 3/2-way valve (MV) according to one of the Claims 12 until 14 , characterized in that in a second position of the magnet armature (4), the first hydraulic connection (HV1) is closed and the second hydraulic connection (HV2) is open. 3/2-way valve (MV). Claim 15 , characterized in that the second position of the magnet armature (4) is achieved by not energizing the 3/2-way valve (MV) and its valve fields (VF). 3/2-way valve (MV) according to one of the Claims 12 until 16 , characterized in that a first connection (AN1) of the 3/2-way valve (MV) is hydraulically connected to the first valve chamber (K1) for connection to the one brake circuit (BK1), and that a second connection (AN2) of the 3/2-way valve (MV) for connecting the 3/2-way valve (MV) to the second brake circuit (BK2) is hydraulically connected to the second valve chamber (K2), and that a third connection (AN3) of the 3/2-way valve (MV) for connecting the 3/2-way valve (MV) to the pressure supply device (DV) is hydraulically connected to the third valve chamber (K3). 3/2-way valve (MV) according to one of the Claims 9 until 17 , characterized in that the first valve seat (VS1) is arranged on the magnet yoke (6) of the magnet armature (4) or a region of the magnet yoke (6) is designed as a first valve seat (VS1). 3/2-way valve (MV) according to one of the Claims 12 until 18 , characterized in that the excitation coil (5) is cast with the housing of the 3/2-way valve (MV) and / or at least one heat sink (10) or at least one heat exchanger unit is arranged on the housing. 3/2-way valve (MV) according to one of the Claims 12 until 19 , characterized in that the excitation coil (5) is cast with the magnet housing.

Images