CN2075618U

CN2075618U - Auxiliary forcing device for hydraulic servo brake

Info

Publication number: CN2075618U
Application number: CN 90222338
Authority: CN
Inventors: 陈应坚
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-10-14
Filing date: 1990-10-14
Publication date: 1991-04-24

Abstract

The utility model relates to an auxiliary forcing device for brake, comprising a housing 1, a valve core 2, a plunger piston 7 and a servo valve core 6, wherein, the valve core 2 which is controlled by brake fluid controls an oil inlet 22 and the opening and closing of a return port 36; the plunger piston 7 can actively be arranged in a lining 9; the servo valve core 6 is arranged in the housing 1; the pressure oil of an auxiliary forcing chamber 32 can act on the end surface 33 of the valve core 6, and is transferred to the plunger piston 7. The utility model is suitable for vehicle brake systems with middle and high voltage hydraulic pressure systems. Compared with the existing brake system, the utility model has the advantage of acquiring very large magnification with lower control pressure, having the advantages of simple structure, small dimension, etc.

Description

Auxiliary forcing device for hydraulic servo brake

The utility model relates to a kind of vehicle brake control apparatus, particularly a kind of hydraulic servo brake servo-unit.Be applicable to the motor vehicle braking system that has the mesohigh hydraulic efficiency pressure system, have with lower control presssure and obtain advantages such as very big magnification factor and size simple in structure are little.

The servo brake that extensively adopts has servo vacuum braking and air servo brake at present.The servo force source of servo vacuum braking can be from the vacuum source behind the throttle gate in vacuum pump or the engine air inlet tube, and less because of its pressure reduction, the size of servo vacuum air chamber is very big.Air servo brake need dispose air compressor, air tank, oil water separator, control cock and air servo air chamber etc., its form than vacuum Fu complexity many.

Hydraulic servo brake, because of its servo pressure is very high, its servo chamber size is very little, again because of its pressure oil can with turn to, job family is shared, so the hydraulic servo brake system architecture is simple and size is less.

The utility model provides a brake servo unit, has a housing 1, and interface 21, of configuration one logical master brake cylinder connects an interface 42 and the interface 37 that the interface 22, of high pressure oil links to each other with drg on it; The open and close of one control spool 2 control oil inlets 22 and return opening 36, in a through hole 27 logical counter balance pocket 29 are arranged; One plunger 7 is configured in the lining 9 movably, and pressure chamber 41 and oil back chamber 34 are separated; One servo spool 6 is configured in the housing 1 movably; The direction of mobile control presssure oil by control spool 2 makes pressure oil might act on spool 6 and promotes plunger 7 and moves, and makes plunger compression brake liquid produce braking.

Do one referring now to 1 pair of the utility model of accompanying drawing and describe, an embodiment of accompanying drawing one expression utility model.

Interface 21 on the brake servo unit connects the master brake cylinder outlet, and interface 22 connects high pressure oil, and interface 42 connects brake cylinder, interface 37 connected tanks.Under graphic off position, control spool 2 is closed oil inlet 22 and is opened the return opening 36 of oil sump tank.When vehicle operator is stepped on brake pedal, the braking liquid of master brake cylinder output is through interface 21, runner 39, hole 38 enters pressure chamber 41, flow into brake cylinder by interface 42 again, put drg also generation braking to a certain degree in the ready position that begins to brake, simultaneously, braking liquid also acts on the end face 23 of control spool as control liquid.When modulated pressure power is increased to certain value, overcome the elastic force of spring 3 and make control spool 2 toward moving right, close return opening 36 earlier, spool further moves to right, progressively open oil inlet 22, pressure oil enters chamber 25 through interface 22, runner in spool 27 flows into counter balance pocket 29 again, per os 30, runner 31 enters power-assisted chamber 32, acts on the end face 33 of servo spool 6 and promote sliding plug 7 to move to left, sliding plug 7 was moved after the aperture 38, add the braking liquid that is pressed in the chamber 41, braking liquid flows into brake cylinder by interface 42, produces brake action.The elastic force of spring 3 can be adjusted by the pad 5 that increases and decreases an end.Pressure oils in the counter balance pocket 29 act on the end face 28 of control spool simultaneously and the application force of spring 3 together the balanced system hydrodynamic act on application force on the control spool end 23, spool is tended to balance in a certain position.When vehicle operator further depresses brake pedal, then the pressure of braking liquid further increases, the application force that acts on this moment on the control spool end 23 also increases, promoting spool 2 further moves to right, the aperture of oil inlet 22 strengthens, pressure oil further flows into the increased pressure that counter balance pocket 29 and power-assisted chamber 32 make two chambeies, promote on the one hand move to left braking liquid in the further compressed pressure chamber 41 of servo spool 6 and sliding plug 7, act on the end face 28 of control spool on the other hand, make the control spool reach balance in new position.When the vehicle operator loosen the brake, the pressure that acts on the control spool end 23 is removed, move to left rapidly under the pressure oil effect of control spool in spring 3 and counter balance pocket and reset, pressure in the power-assisted chamber 32 descends rapidly, under the effect of braking liquid in pressure chamber 41 and pull back spring 8, sliding plug 7 moves to right rapidly, opens aperture 38 pressure in the pressure chamber is reduced rapidly, and brake action is removed.

Just in case pressure oil circuit et out of order and can not set up pressure, vehicle operator is stepped on brake pedal, and braking liquid is through interface 21, runner 39, and aperture 38, pressure chamber 41 directly enters brake cylinder, and vehicle is produced to a certain degree braking.

The utility model hydraulic servo brake servo-unit has possessed the advantage of brake servo unit in the past and has got rid of its weak point.At first, control presssure that can be lower obtains very high brake-pressure, can obtain very big " amplification " multiple.And can change as required 6 end faces 33 of servo spool when of control spool 2 end faces 28 and 23 area and plunger 7 end faces 40 area recently adjust magnification factor.The second, its pressure oil of this brake servo unit with turn to, job family is shared, so simple in structure and oad is less.

One is proficient in the operator might make many changes to the utility model described here, and such change also is prescribed and is included within the claims scope.

Claims

1, a kind of brake servo unit has a housing 1, the interface 21 of configuration one logical master brake cylinder, one connects the interface 22 of high pressure oil, one interface that links to each other with drg 42 and one takes back the interface 37 of oil, the open and close of one control spool 2 control oil inlets 22 and return opening 36, in a through hole 27 logical counter balance pocket 29 are arranged; One plunger 7 is configured in the lining 9 movably, and pressure chamber 41 and oil back chamber 34 are separated, and a servo spool 6 is configured in the housing 1 movably, and pressure oil can act on the end face 33 of spool 6 and pass to plunger 7.It is characterized in that brake servo unit comprises that one is configured in the control spool 2 in the housing 1, one spring 3, one shim pack 5, one plunger 7, one servo spool 6 and a pull back spring 8, by moving of control spool 2, the direction of control presssure oil makes pressure oil might act on spool 6 and promotes plunger 7 and moves.

2, brake servo unit according to claim 1 is characterized in that its magnification factor can be by changing control spool 2 two ends 28,23, and the area of servo spool 6 end faces 33 and plunger 7 end faces 40 is adjusted.

3, brake servo unit according to claim 1 is characterized in that being controlled by the elastic force of spring 3 the initiation point of spool 2, and the elastic force of spring 3 can be adjusted by the pad 5 of increase and decrease one end.