JPH05185914A - Hydraulic brake apparatus with anti-skid device - Google Patents

Abstract

PURPOSE: To reduce switching noise and the pedal reaction by by-passing a shut-off valve by a by-pass line, installing a throttle in this by-pass line, and making the shut-off valve assume a prescribed shut-off position during anti-skid control operation. CONSTITUTION: When a wheel disposed in a wheel brake 8 rotates stably, a control device 46 switches the phase to a phase for increasing brake pressure. Moreover, a shut-off valve 15 in a brake line 5 assumes a prescribed shut-off position 15b, so that a partial pressure medium flows into the wheel brake 8 through a by-pass line 16 with a throttle 17 and a brake line 6 by an operated master brake cylinder 3. In this case, the throttle 17 reduces the rate of brake pressure increase in the wheel brake 8, thereby generating only small noise when an inlet valve 23 is switched repeatedly to the phase for increasing the brake pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pedal operated master brake cylinder having a valve device for modulating a pressure medium for switching between pressure rising, pressure holding and pressure decreasing stages in a wheel brake. A brake conduit extending between at least one wheel brake, (b) a high pressure pump for delivering a pressure medium into the brake conduit between the master brake cylinder and the valve device, and (c) a master brake cylinder and a high pressure pump. Liquid with anti-skid device of the type, especially for motor vehicles, which is arranged in the brake line between the connection to the brake line and which has a sluice valve which can be switched into a predetermined shut-off position by a control device. The present invention relates to a pressure brake device.

[0002]

PRIOR ART German patent application No. 40341
In the hydraulic brake system of the type previously proposed by 13.5, wheels which are unduly exposed to large drive slip by the pump in the drive slip adjustment operation, which is additionally possible for the antiskid adjustment operation, are proposed. When the brake pressure is increased in the wheel brakes, the sluice valve in the brake conduit between the master brake cylinder and the high pressure pump is switched to the shut-off position. The bypass conduit, which is arranged parallel to the sluice valve, has a flow direction from the master brake cylinder to the wheel brakes, and in order to allow a braking action operated by the driver during the drive slip adjustment operation. used. When the sluice valve is closed and locked in a predetermined shut-off position, the return of the pressure medium from the wheel brakes is blocked, so that the sluice valve causes a serious failure of the braking device.

When the sluice valve occupies a predetermined flow-through position during the anti-skid adjustment operation, the pressure medium taken out from the wheel brake of the wheel which has a tendency to lock on one side is returned to the master brake cylinder and conveyed to the other, and In terms of pressure, the pressure medium can be transferred from the master brake cylinder to the wheel brakes. However, since the valve device for brake pressure modulation arranged in the wheel brakes performs a switching operation with a large acceleration and delay of the pressure medium in the brake conduit in a short time, especially in the stage for pressure increase, Particularly during anti-skid adjustment operation, significant noise and vibration of the brake pedal are generated which impairs the comfort of the brake system or the vehicle.

[0004]

SUMMARY OF THE INVENTION The object of the invention is to improve the comfort of the braking system.

[0005]

Means for Solving the Problems In the means of the present invention taken to solve the above-mentioned problems, the sluice valve is bypassed by a bypass conduit, and the bypass conduit is provided with a throttling portion. The sluice valve occupies a predetermined shutoff position during the anti-skid adjustment operation.

[0006]

The advantages obtained by the present invention are that the pressure medium must overcome the throttling points during the pressure-increasing stage of the antiskid conditioning operation, which results in a reduction of the flow velocity of the pressure medium stream. That is, the rate of pressure increase at the time of switching the valve device is reduced. This significantly reduces the switching noise intensity during the pressure rise stage during antiskid adjustment operation. Furthermore, the reaction of pressure medium delivery from the master brake cylinder to the brake pedal is hardly annoying to the driver.

Further, according to the configuration described in claim 2, the pressure medium can bypass the sluice valve and flow out to the master brake cylinder via the check valve in the pressure reduction stage. Due to this, a failure of the sluice valve has almost no effect on the functioning of the braking device, since in most cases a quick brake release and a return guide of the pressure medium to the master brake cylinder are guaranteed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The hydraulic multi-circuit braking system 1 for a motor vehicle shown in the drawing comprises an antiskid device 2. The braking device 1 comprises a pedal-operated master brake cylinder 3 with an attached pressure medium-storage container 4. From the master brake cylinder 3,
The brake line 5 of the first brake circuit I arranged on the front axle of the motor vehicle departs. The brake conduit 5 is branched into two brake conduits 6 and 7. Brake conduit 6
Communicates with, for example, the wheel brake 8 of the left front wheel (not shown). The brake conduit 7 is likewise connected to a wheel brake 9, not shown, for example on the right front wheel.

A brake conduit 10 of a second brake circuit II also departs from the master brake cylinder 3, in which wheel brakes 11, 12 of the rear axle of the motor vehicle are arranged. Brake circuit II
Are not necessary for the present invention and will not be described in detail.

In the brake conduit 5 of the brake circuit I, a sluice valve 15 is arranged in the form of a 2-port 2-position directional control valve. This sluice valve 15 is provided with a spring-operated flow-through position 1
5a and a shut-off position 15b capable of electromagnetic switching.
The sluice valve 15 is bypassed by a first bypass conduit 16, which is provided with a throttling point 17. Furthermore, a second bypass conduit 18 bypassing the gate valve 15 is provided, in which a spring-loaded check valve 19 is arranged. Check valve 19
From the master brake cylinder 3 to the wheel brakes 8,
Shut off in the 9 direction.

The wheel brake 8 is provided with a valve device 22 for modulating the brake pressure. The valve device 22 comprises an inlet valve 23 and an outlet valve 24. Both valves 23 and 24
Is designed as a 2-port 2-position directional control valve.
The inlet valve 23 arranged in the brake conduit 6 has a spring-operated flow-through position 23a and an electromagnetically switchable shut-off position 23.
b. The inlet valve 23 is the third bypass conduit 25
A check valve 26 is located in this bypass conduit and is closed in the direction from the master brake cylinder 3 to the wheel brakes 8. Outlet valve 2 of valve device 22
4 is provided in the extension of the return conduit 27, which originates from the brake conduit 6 between the inlet valve 23 and the wheel brake 8. The outlet valve 24 is a spring-operated shut-off position 24a and an electromagnetically switchable flow-through position 24b.
And have.

In a similar manner, the wheel brake 9 is provided with a valve device 32 for brake pressure modulation, which comprises an inlet valve 29 in the brake line 7 and an outlet valve 30 in the return line 31. There is.

Like the valve device 32, the valve device 22 can be switched to a switching position for increasing the pressure, maintaining the pressure and decreasing the pressure in the wheel brake 8. In the switching position for increasing pressure, as shown, the inlet valve 2
3 occupies a predetermined flow-through position 23a, and the outlet valve 24 occupies a predetermined shut-off position 24a. In the switching position for holding pressure, the inlet valve 23 as well as the outlet valve 24 are switched to a predetermined shut-off position 23b. In the switching position for reducing the pressure, the inlet valve 23 occupies a predetermined shut-off position 23b and the outlet valve 24 is switched to a predetermined flow-through position 24b.

The return conduit 27 used for the return of the pressure medium taken out of the wheel brakes 8, 9 leads to the suction-side connection 35 of a high-pressure pump 37 driven by an electric drive motor 36. Further in the return conduit 27,
A storage chamber 38 for the intermediate storage of the pressure medium is connected. A supply conduit 40 departs from the discharge-side connection 39 of the high-pressure pump 37, which supply conduit opens between the sluice valve 15 and the valve device 22 in the brake conduit 6. The supply conduit 40 is provided with a throttling point 42 with a damping chamber 41 and a pressure limiting valve 43 connected in parallel when viewed in the flow direction.

Furthermore, the brake system 1 has an electronic control unit 46, which is a rotation speed sensor 4
7,48,49,50 via the valves 48,49,50 to monitor the pressure condition of the wheels (not shown) and to adjust the valves 15,23,24,29,30 and the high pressure pump 37 in accordance with the predetermined adjustment algorithm during the antiskid adjustment operation. The drive motor 36 is switched.

The operation of the braking device is as follows:
In the braking operation released by the driver of the automobile, that is, the sluice valve 15 and the valve devices 22, 3
While the two valves 23, 24, 29, 30 occupy the positions shown, in the brake conduits 5, 6, 7 of the brake circuit I caused by the operation of the master brake cylinder 3, as well as in the brake conduit 10 of the brake circuit II. A brake pressure is formed in the wheel brakes 8, 9, 11, 12 by the movement of the amount of pressure medium. In this case, the control device 46 monitors the rotation state of the wheels based on the signals from the rotation speed sensors 47, 48, 49 and 50.

In such a braking operation, for example, when the wheels arranged on the wheel brake 8 tend to lock,
The control device 46 switches the sluice valve 15 in the brake conduit 5 to the shut-off position 15b and the valve device 2 in the brake conduit 6
2 is switched to the switching position for pressure drop. From the wheel brakes 8, the pressure medium now flows through the return conduit 27 into the storage chamber 38, so that the brake pressure in the wheel brakes 8 drops. The high-pressure pump 37, which is switched over simultaneously by the control device 46, delivers the pressure medium taken from the wheel brakes 8 into the brake line 6 by means of the supply line 40. In this case, the damping chamber 41 has the throttling point 4
2 dampenes the pulsation caused by the high-pressure pump 37 and thus overcomes the check valve 19 by means of the second bypass conduit 18 and by the brake conduit 5 into the master brake cylinder 3 to the master brake cylinder 3. Causes almost no pedal return action.

It is also possible to connect to this stage for braking pressure reduction a stage for pressure holding and pressure reduction switched by the valve device 22. In the stable wheel rotation state of the wheels arranged in the wheel brake 8, the control device 46 switches to the stage for increasing the brake pressure. Furthermore, the sluice valve 15 in the brake conduit 5 occupies a predetermined shut-off position 15b, so that the pressure medium part quantity passes through the first bypass conduit 16 and the brake conduit 6 which have a throttling point 17 by the operated master brake cylinder 3. Flows into the wheel brakes 8. In this case, the throttling point 17 causes a decrease in the braking pressure rising speed in the wheel brake 8. Therefore, the repeated switching of the inlet valve 23 in the stage for increasing the brake pressure produces only a small noise and reduces the pedal return action in the master brake cylinder 3.

When the antiskid adjustment operation is completed,
The control device 46 switches the sluice valve 15 to the flow-through position 15a and the valve device 22 so that the inlet 23 and the outlet valve 24 are in the positions shown. Furthermore, the drive motor 36 of the high-pressure pump 37 is switched off.

Gate valve 15, throttling point 17 and check valve 19
Are preferably arranged in the brake circuit arranged on the front axle of the motor vehicle, as previously mentioned, which means that during the anti-skid adjustment operation, a relatively large amount of pressure medium is applied to the master brake. This is because it has to be moved between the cylinder 3 and the wheel brakes 8, 9. But,
The aforementioned components can also be arranged in the rear axle-brake circuit. Furthermore, the arrangement of the members can be used in a so-called cross piping brake circuit, that is, in a brake device in which the wheel brakes of the diagonally arranged wheels are arranged in the brake circuit. ..
The sluice valves, throttles and check valves can be arranged on all brakes of the respective brake circuit, or on the front axle brake only or on the rear axle brake only. In this case, the brake system is based on the prior art mentioned in the opening paragraph (German patent application 403411).
It is also possible to have a drive slip adjuster, as is the case in U.S. Pat. No. 3.5).

[Brief description of drawings]

1 is a circuit diagram of a hydraulic multi-circuit-brake device for a motor vehicle.

[Explanation of symbols]

1 brake device, 2 anti-skid device, 3
Master brake cylinder, 4 pressure medium-storage container, 5,6,7 brake conduit, 8,9 wheel brake, 10 brake conduit, 11,12 wheel brake, 15 gate valve, 15a flow position, 15b
Shut-off position, 16 bypass conduit, 17 throttling point, 19 bypass conduit, 19 check valve, 22
Valve device, 23 inlet valve, 23a flow-through position, 23
b shut-off position, 24 outlet valve, 24a shut-off position,
24b Overflow position, 25 Bypass conduit, 26
Check valve, 27 Return conduit, 29 Inlet valve, 30
Outlet valve, 31 Return conduit, 32 Valve device, 35 Suction side connection part, 36 Drive motor, 37 High pressure pump, 38 Storage chamber, 39 Discharge side connection part, 40
Supply conduit, 41 damping chamber, 42 throttling point, 43
Pressure limiting valve, 46 control device, 47, 48, 4
9,50 RPM sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Günter Schmidt Federal Republic of Germany Tam-Hohenstanghe Backnanger Weg 13 (72) Inventor Wolfgang Bernhard Korntal Towitzerstrasse 21

Claims (2)

[Claims] 1. A hydraulic brake device (1) having an anti-skid device, especially for motor vehicles, comprising:
Valve arrangement (22) for pressure medium modulation, switching between pressure build-up, pressure hold and pressure drop stages in wheel brakes
A brake conduit (5, 6) extending between a pedal operated master brake cylinder (3) and at least one wheel brake (8), and (b) a master brake cylinder (3) and a valve device (22). High pressure pump (37) for delivering pressure medium into the brake conduit (6) between
And (c) is arranged in the brake conduit (5) between the master brake cylinder (3) and the connection of the high-pressure pump (37) to the brake conduit and is switched by the control device (46) to a predetermined shut-off position. In the type provided with a possible sluice valve (15), (d) the sluice valve (15)
Is bypassed by a bypass conduit (16), which is provided with a throttling point (17),
(E) A hydraulic brake device having an anti-skid device, wherein the sluice valve (15) occupies a predetermined shut-off position (15b) during an anti-skid adjustment operation. 2. A second bypass conduit (18) bypassing the sluice valve (15), in which a check valve (19) is arranged, the check valve (19). 2. A hydraulic brake system as claimed in claim 1, characterized in that the brake is interrupted in the direction from the master brake cylinder (3) to the wheel brake (8).