JPS6094861A - Hydraulic brake gear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The invention relates to a hydraulic brake system comprising a mask cylinder combined with a replenishment tank and connected to a wheel brake cylinder via a brake conduit, comprising an anti-skid mechanism. This invention relates to a type in which a drive prevention mechanism is combined.

BACKGROUND OF THE INVENTION This German hydraulic brake system is known, for example, from German Patent Application No. 3,215,739.

In this known hydraulic brake device, the anti-skid mechanism is combined with a drive slip prevention mechanism (wheel spin prevention device). During anti-skid operation, the braking pressure of the wheel brake is changed by the braking pressure control shaft valve. In that case, in order to reduce the braking pressure, pressure medium is discharged into the chamber through the brake valve 111, and this discharged pressure medium is transferred by a return pump to the connection between the mask cylinder and the brake pressure control medium. returned to the department.

Problems to be Solved by the Invention The drive slip prevention mechanism includes a pressure accumulator, in which the braking medium to be controlled when the drive slip prevention mechanism acts for brake operation is supplied by a return pump. The power is saved. This drive slip prevention mechanism is equipped with a solenoid valve, which cuts off the connection between the mask cylinder and the split part 1 valve when adjusting the drive slip, connects the pressure accumulator to the inlet of the control cage outlet valve, By using one control valve and one control circuit, the braking pressure is controlled by one control circuit to change it in the direction of suppressing drive slip.

Therefore, the drive slip protection mechanism requires a high pressure accumulator. A disadvantage that arises when charging this pressure accumulator is that a negative pressure is created during suction, which causes air bubbles to form in the pump suction conduit, leading to the pump becoming inoperable.

Means of the Invention Solving the Problem The means of the invention which solves the above problem is that the high-pressure pump and the low-pressure pump are equipped with one pressure accumulator charge valve, and the low-pressure pump 0 is connected to the wheel brake cylinder of the drive wheel. It is located in the supply circuit of the connected mask cylinder.

The brake system shown in the drawings includes a hydraulic tandem master cylinder 1 (hereinafter simply referred to as master cylinder). Two brake conduits are led out from this mask cylinder 1, and one brake conduit (not shown) leads to a brake nozzle cylinder (not shown) of a front wheel that is not driven, and an external brake stand. The pipe 2 connects the two rear wheels 1 @6°70 driven via the differential gear 5.
It leads to two brake nolinders 3 and 4. Pregi Monument 'ef2 has two 2's in front of brake cylinders 3 and 40.
It is divided into 8 pipe branches 2', 2'', and each pipe branch 2', 2'' is equipped with a control valve with 6 ports and 6-position solenoid valves (hereinafter referred to as 6/6 solenoid valves). ) 8 and 9 are connected in 4 lines, and this solenoid valve 6/lo is a check valve t.
o, 1i provides a bypass in the direction towards the mask cylinder IN:l +1-.

Each 3/6 solenoid valve 8,9 has a connection 12.13 for each return line 14.15 connected to the high-pressure pump 16 and a connection 17.18 for a line branch 2', 2''. The pressure conduit 1 is connected to the conduit branches 2' and 2''.
The pressure side of the high-pressure pump 16 is connected via 9.

The return conduits 14 , 15 lead to the accumulator charge valve 21 via a common return conduit 20 . A check valve 22, a relief valve 23, and a low pressure accumulator 24 are provided within the accumulator charge valve 21.

A 6-bot 2-position solenoid valve (hereinafter referred to as 6/2 solenoid valve) 25 is provided in the brake conduit 2.
In the illustrated position of this 6/2 solenoid valve 25, the brake conduit 2 is in communication, and in the second position when the solenoid is energized,
Conduit branches 2', 2'' connected to the pressure line 19 are connected to a high-pressure accumulator 26 and a pressure switch 27.

The mask cylinder 1 is combined in a conventional manner with a replenishment tank 28, which has two chambers 29.3 (I
The two chambers 29 and 30 are separated by separate conduits 31.
It is connected to the mask cylinder 1 via 32. 4
A low-pressure pump 33 is provided in the pump 31, and this low-pressure pump is driven by an electric motor 33', and when the pump is stopped, the brake fluid passes through in both directions without pressure. To do this, the low-pressure pump 33 is designed as a hydrodynamic pump, for example a rotary pump or a centrifugal pump. In practice, the conduits 31, 32 consist of passages, the low-pressure pump 33 is integrated directly into the replenishment tank 28, and the electric motor 33' is installed outside the replenishment tank 28, i.e. "dry".
be followed by himself.

Operation In a typical brake system, the brake fluid passing through the low pressure pump 33 and the 3/2 solenoid P25 is not controlled.

When one of the rear wheels 6, 7 shows a lock frequency, a sensor (not shown) attached to the wheel will respond accordingly.
A signal is transmitted to the filter solenoid, which causes the filter to move.
6 solenoid valves are switched to the second position (pressure hold) or to the sixth position (pressure reduction). Simultaneously with the switching of the 6/6 solenoid cell, the high-pressure pump 16 is connected for returning the volume of relief medium to the mask cylinder via the conduit branch 2'' and the brake conduit 2.

When one of the rear wheels 6 and 7, for example the rear wheel 6, spins, a sensor detects this and activates the 6/2 solenoid valve 25.
And a signal is applied to the 6/6 solenoid valve 9 of the rear wheel 7 that is not idling. 6/2 solenoid valve 25 and 6/2
6 solenoid valve 9 is switched, thereby connecting the pressure accumulator 26 to the conduit branches 2' and 2'', and the 3/6 solenoid valve 9 is switched to the pressure holding position, so that the brake fluid is Via the non-switched 6/6 solenoid valve 8, only the brake cylinder 3 of the idling rear wheel 6 can be reached.The non-siding rear wheel 7 releases its rotational force and stops the vehicle. The magnitude of the pressure is varied by a control circuit (not shown) depending on the fixed drive slip.

However, in order to prevent drive stress, the high pressure accumulator 26
A charge must be ensured. This is obtained in conjunction with the low-pressure pump 33 used to generate the prepressure in the suction conduit of the high-pressure pump.

Advantages of the present invention L! According to IJ, a high pressure pump is combined with a low pressure pump, thereby avoiding negative pressure in the °C1 supply circuit. Therefore, no bubbles are generated. Drive slip prevention (when the E machine width is not operating, the brake fluid flows through the low-pressure pump in both directions, and this prevents the flow of the brake fluid during the normal operation of the brake release +i + j movement). I can't kick it.

Another advantage is that the dedicated brake can be used for two purposes. For accumulator charging carried out by commercial accumulators,
No additional conduit to the refill tank is required.

According to the invention, operational reliability is obtained, and the hydrodynamic low-pressure pump used in the invention 3
3, the generation of negative pressure in the system is avoided. Low pressure zJ
? Nbu33 itself is also an extremely cheap piece due to its simple construction.

[Brief explanation of drawings]

The drawing is a hydraulic circuit diagram of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Tandem type mask cylinder, 2... Brake conduit, 2', 2''... Conduit branch path, 3, 4... Brake cylinder, 5 Differential, 6. 7...i
Wheels, 8.9...6-bottom, 6-position solenoid valve, 10
, 11... Check valve, 12.13... Connection part, 1
4.15...Return conduit, 16...High pressure pump, 17.
18・Connection part, 19・Pressure conduit, 20・Return conduit, 2
1... Pressure accumulator charge valve, 22... Check valve, 2
3...Relief valve, 24...Low pressure accumulator, 25...6
Bottom 2-position solenoid valve, 26...High pressure accumulator, 27
...Pressure switch, 28...Replenishment tank, 29.3
0...Room, 31.32...Conduit, 33...Low pressure pump, 33'...Electric motor (1 other person)

Claims (1)

[Claims] 1. Hydraulic brake system with a mask cylinder combined with a replenishment tank and connected to a wheel brake cylinder via a brake conductor - Q'Xi, an anti-skid mechanism and a drive slip prevention mechanism. In the type that is combined with high pressure pump (16) and low pressure pump (3'3)/J, one livestock LI: vessel charge valve (2
1), and the low pressure pump (33) is connected to the mask cylinder (3, 4) of the wheel brake cylinder (3, 4) of the driver's car 1'ini (6, 7).
A hydraulic brake device characterized in that it is disposed within the supply circuit (31) of item 1). 2.u! lIE 71 pump (33) is replenishing tank (2
8) within the area of I! A hydraulic brake system according to claim 1, which allows braking fluid to flow through the IL in a stationary state. 3. Hydraulic brake system according to claim 1 or 2, in which the low-pressure pop (33) comprises a hydraulic pump which allows brake fluid to flow through in both directions in the stopped state. 4. Any one of claims 1 to 6, wherein the replenishment tank (28) of the mask cylinder (1) is formed as a casing of a low-pressure pump (33) 11]1
lli! Hydraulic brake system as described. 5. The drive motor (33') of the low-pressure pump (33) is formed as an electric motor and is dryly arranged outside the replenishment tank (28). Hydraulic brake device according to any one of the items.