KR20050103744A - A vacuum booster structure of a brake for a vehicle - Google Patents

Abstract

The present invention relates to a vacuum booster structure of a vehicle brake, the technical configuration of the front and rear diaphragm partitioning the interior of the front and rear housing is sealed in the front positive, transformer and rear positive and transformer chambers and the center plate in the center And front and rear chamber is provided; A control valve and an air valve piston for controlling communication of vacuum or atmosphere to the front and rear chambers; In the vacuum booster structure of a vehicle brake including a power piston interlocking with the front and rear diaphragms, the front and rear chambers communicate with a predetermined position of the center plate so that the rear chamber, which is an atmospheric pressure chamber, can be vacuumed. A valve housing having an air flow path formed therein, a spring support jaw protruding from one end of the valve housing, an air cutoff portion provided to be moved left and right by a spring in the air flow passage, and the air cutoff portion It is characterized in that it is provided with a check valve consisting of an air discharge rod which is formed integrally and penetrates the upper and lower sides and a spring support portion recessed into the rear side.

Description

A vacuum booster structure of a brake for a vehicle

The present invention relates to a vacuum booster structure of a vehicle brake, and more particularly, a check valve capable of discharging and interrupting air is installed in a center plate that divides a vacuum chamber and an atmospheric pressure chamber so that the control valve is in a booster stop state. This invention relates to a vacuum booster structure of a vehicle brake that enables the vacuum chamber to be evacuated even in over-contact state, thereby preventing self-applying and enabling zero initial stroke.

In general, a vehicle is provided with a braking device that serves to slow down or stop the vehicle speed during driving.

The braking device includes a booster that doubles the pedaling force of the brake pedal by using a vacuum pressure (engine suction pressure) generated by the engine power, and according to the pressure doubled by the booster. A master cylinder for forming brake oil hydraulic pressure in the brake circuit, and a wheel cylinder for slowing or stopping the rotation speed of the wheel by the brake oil pressure.

Here, the booster may be a vacuum type using a negative pressure of the engine intake manifold and an air type using a pressure provided from a compressor driven by the engine, and a vacuum type is generally used in a small vehicle.

1 is a block diagram showing a vacuum booster according to the prior art.

As shown, the vacuum booster 100 according to the closing technique, the front housing 112 constituting the front chamber 110 which is a vacuum chamber, and the rear housing 122 constituting the rear chamber 120 which is an atmospheric pressure chamber. The center plate 102 which divides the hermetically sealed interior into the front positive / transformer chambers 114a and 114b and the rear positive / transformer chambers 124a and 124b, and to the front chamber 110 and the rear chamber 120. In addition to the control valve (Control Valve) 130 and the air valve piston 160 for controlling the communication of the vacuum or air, the power piston 140 in conjunction with the front and rear diaphragms (118, 128) to be described later, and the brake pedal It is composed of a push rod 150 for transmitting the stepping force, an input shaft 170a interlocked by the brake pedal, and an output shaft 170b for receiving displacement force according to its operation.

Here, the front forward and transformer chambers 114a and 114b and the rear forward and transformer chambers 124a and 124b constituting the front and rear chambers 110 and 120 are formed by the front diaphragm 118 and the rear diaphragm 128. The front and rear diaphragms 118 and 128 are partitioned and supported by the front and rear supports 116 and 126, respectively.

In addition, the control valve 130, the front diaphragm 118 and the front support 116, the center plate 102 and the rear diaphragm 128 and the rear support 126 is coupled to one end portion, the air suction The other end where the portion 172 is formed passes through the central portion of the rear housing 122 and communicates with the atmosphere. In addition, a positive pressure passage (not shown) for communicating the front and rear constant pressure chambers 114a and 124a and the front and rear transformer chambers 114b and 124b, and the atmosphere and the front and rear transformer chambers 114b. , A transformer passage (not shown) for communicating 124b is formed. In addition, a plunger (not shown) sliding in the axial direction with an end of the input shaft 170a is installed inside the control valve 130, and one end of the plunger and one end of the control valve 130 are disposed on the output shaft. It is in contact with the reaction disk 180 provided at the end portion 170b.

Hereinafter, the operation of the brake vacuum booster 100 according to the related art configured as described above will be briefly described.

2 is an enlarged cross-sectional view showing a gap between a power piston and a control valve according to the prior art.

First, in the rest state of the booster 100 before the driver presses the brake pedal, the control valve 130 comes into contact with the air valve piston 160, and at this time, the control valve 130 The gap X of the power piston 115 is about 0.5 ≦ X ≦ 1.0 mm.

In this state, a negative pressure acts on the front chamber 110 from an intake manifold (not shown), and the negative pressure is transmitted to the rear chamber through a gap between the power piston 140 and the control valve 130. At this time, the front and rear chambers 110 and 120, which are divided into the front and rear sides by the center plate 102, are in a negative pressure state, and the front and rear diaphragms 118 and 128 are return springs. It is held at the stop position by the elasticity of the.

In addition, when the driver presses the brake pedal, the booster 100 is in an Initial Apply state. At this time, the control valve 130 is pushed forward by a pressure spring (not shown), thereby providing an air valve piston. While maintaining contact with the 160, the state is brought into close contact with the power piston 140, and the vacuum negative pressure applied to the rear chamber 113 is short-circuited. At this time, when the push rod 150 moves forward slightly to move the air valve piston 160 forward, a slight gap is generated between the power piston 140 and the air valve piston 160 to boost the booster 100. Reaches a partial braking state.

Accordingly, the negative pressure is applied to the front chamber 110 and the atmospheric pressure is applied to the rear chamber 120, but the pressure difference between the front chamber 110, which is a vacuum chamber, and the rear chamber 120, which is an atmospheric pressure chamber is not large, so that the diaphragm 109 is The return spring is gradually compressed while being slightly pushed toward the front chamber 111. At this time, as the return spring is compressed, the rod piston (not shown) is advanced to apply a braking force to the master cylinder (not shown).

In addition, when the push rod 150 is pushed in so that the air valve piston 160 may contact the rod piston, the air valve piston 160 will be discharged from the control valve 130 keeping in close contact with the power piston 140. It will fall completely and will be in full braking state. At this time, the front chamber 110, which is a vacuum chamber, is kept closed in a negative pressure state, and the rear chamber 120, which is an atmospheric pressure chamber, is completely opened and is in an atmospheric pressure state, so that the front and rear chambers 110, 120 The pressure difference is maximum. As a result, the front and rear diaphragms 118 and 128 are advanced as far forward as possible so that the return spring is completely compressed. That is, the driver's brake pedal effort is boosted, and when the brake pedal is further pressed, the driver's effort is directly acted on the master cylinder by the push rod 150.

However, the vacuum booster 101 of the brake according to the prior art as described above is the control valve 130 and the power piston 140 in a stopped state to realize the 'zero initial invalid stroke' of the booster 100. Although the gap X is minimized or maintained in contact with each other, when returning to a stopped state after operation, the front chamber 110, which is a vacuum chamber, and the rear chamber 120, which is an atmospheric pressure chamber, are kept in the same vacuum state. Difficult to make, the control valve 130 and the power piston 140 had a problem in that the self-check (Self Apply) phenomenon appears.

The present invention has been proposed to solve the above problems, by installing a check valve capable of discharging and blocking the air in the center plate partitioning the front chamber and the vacuum chamber of the vacuum chamber, the power control valve in a stationary state The purpose of the present invention is to allow the vacuum chamber to be evacuated even when in contact with the piston, thereby preventing self-applying and enabling 'zero initial invalidation stroke'.

In order to achieve the above object, the present invention provides a front and rear diaphragm that divides the interior of the front and rear housings into an airtight coupling chamber and a rear forward transformer transformer, and a front and rear chamber having a center plate at the center thereof. ; A control valve and an air valve piston for controlling communication of vacuum or atmosphere to the front and rear chambers; In the vacuum booster structure of a vehicle brake including a power piston interlocking with the front and rear diaphragms, the front and rear chambers communicate with a predetermined position of the center plate so that the rear chamber, which is an atmospheric pressure chamber, can be vacuumed. A valve housing having an air flow path formed therein, a spring support jaw protruding from one end of the valve housing, an air cutoff portion provided to be moved left and right by a spring in the air flow passage, and the air cutoff portion It provides a vacuum booster structure of a vehicle brake provided with a check valve consisting of an air discharge hole is formed integrally with the air discharge hole to penetrate the upper and lower sides and a spring support recessed into the rear side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First of all, among the technical components of the present invention, the front housing 22 constituting the front chamber 20 of the booster 10, the front positive and transformer chambers 24a and 24b, the front support 26, and the front diaphragm 28 ), The rear housing 32 constituting the rear chamber 30, the rear positive and transformer chambers 34a, 34b, the rear support 36, the rear diaphragm 38, the center plate 12, the control valve 40 The power piston 50, the push rod 60, the air valve piston 70, the input shaft 80a, the output shaft 80b and the air intake 82 are well known techniques, so detailed descriptions thereof will be omitted herein. A check valve 90 is provided at a predetermined position of the center plate 12 to communicate the front and rear chambers 20 and 30 so as to vacuum the rear chamber 30 which is an atmospheric pressure chamber.

Figure 3 is a schematic configuration diagram showing a vacuum booster according to the present invention, Figure 4 shows a check valve provided in the center plate according to the present invention, Figure 4a shows the check valve in the booster stopped state Fig. 4B is a use state diagram showing a check valve in a booster operation state.

That is, as shown, according to the structure of the vacuum booster 10 of the vehicle brake according to the present invention, the front and rear housings 22 and 32 are hermetically coupled to the front positive and transformer chambers 24a and 24b. Front and rear chambers 30 provided with front and rear diaphragms 28 and 38 partitioned into rear forward and rear pressure chambers 34a and 34b and a center plate 12 in the center thereof; A control valve (40) and an air valve piston (70) for controlling communication of vacuum or atmosphere to the front and rear chambers (20, 30); In a vacuum booster structure for a vehicle brake including a power piston 50 interlocking with the front and rear diaphragms 28 and 38, the front and rear chambers 20 and 30 are located at predetermined positions of the center plate 12. ) Is provided with a check valve (Check Valve) 90 to communicate with the vacuum chamber to the rear chamber 30, which is an atmospheric pressure chamber.

Here, the check valve 90 has a valve housing 91 in which an air flow path 91a is formed at the center thereof, thereby forming an outer shape thereof. The air flow path 91a serves as a passage for transferring a vacuum state from the front chamber 20, which is the vacuum chamber, to the rear chamber 30, which is an atmospheric pressure chamber.

One end of the valve housing 91 is provided with spring support jaws 91b-1 and 91b-2 for supporting the spring 93 to be described later. The spring support jaws 91b-1 and 91b-2 are provided to be bent and protruded into the belt housing 91.

In addition, an air blocking unit 92a that moves left and right along the air passage 91a is provided inside the valve housing 91. The air shutoff portion 92a is provided with an air discharge hole 92b-1 provided to penetrate the upper and lower sides thereof and an air push rod 92b provided with a spring support portion 92b-2 recessed into the rear side. It is preferable to form integrally with.

In addition, one end of the spring 93 is supported by the spring support jaws 91b-1 and 91b-2 of the valve housing 91 to the spring support 92b-2 of the air push rod 92b. It is formed to have a diameter larger than the other end supported by the to enable a buffering action in the valve housing (91).

That is, before stepping on the brake pedal, the air valve piston is contacted by the air valve piston 70 and the control valve 40 spaced apart from the power piston 50 causes the air valve piston to move forward as the push rod 60 steps on the brake pedal. A process of releasing the vacuum power as the push rod 60 is reversed as the push rod 60 is reversed while falling from the 50 and contacting the power piston 50 (after operation, returns to the rest state. In the front chamber 20, which is a vacuum chamber, when air flows in through the air passage 91a provided at the center of the valve housing 91, the air blocking unit integrally formed by the buffering action of the spring 93 92a) and the air push rod 92b are pushed to the back positive and pressure transformation chambers 34a and 34b of the rear chamber 30. As shown in FIG.

At this time, the vacuum state of the front chamber 20 is transferred to the rear chamber 30 which is an atmospheric pressure chamber by the air discharge hole 92b-1 of the air push rod 92b and the front chamber 20 and The rear chamber 30 will be able to achieve the same vacuum.

In addition, during the operation of the booster 10, the air flow path (91a) of the check valve 90 by the buffering action of the spring 93, the air blocking portion 92a and the air push rod (92b) on the drawing It can be seen that the movement to the left to block the air (see Fig. 4b).

Therefore, according to the vacuum booster structure of the vehicle brake of the present invention configured as described above, the control valve 40 and the power piston in the stopped state to realize the 'zero initial invalid stroke' of the booster 100 Even if the gap (X, see FIG. 2) with the 50 is minimized or kept in contact, the check valve 90 provided in the center plate 12 is returned to the stop state after the operation. Since the front chamber 20, which is the vacuum chamber, and the rear chamber 30, which is the atmospheric pressure chamber, can be maintained in the same vacuum state, the zero initial invalid stroke can be enabled and the self-applying phenomenon can be prevented. Will be.

As described above, according to the vacuum booster structure of the vehicle brake according to the present invention, the control valve is a power piston in a stopped state by installing a check valve capable of discharging and blocking air in the center plate that divides the vacuum chamber and the atmospheric pressure chamber. By allowing the atmospheric pressure chamber to be evacuated even in the contact state, it is possible to prevent self-apply and to enable 'zero initial invalidation stroke'.

While the invention has been shown and described with respect to particular embodiments, it will be understood by those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the appended claims. Anyone can grow up easily.

1 is a schematic diagram showing a vacuum booster according to the prior art.

Figure 2 is an enlarged cross-sectional view showing a gap between a power piston and a control valve according to the prior art.

Figure 3 is a schematic diagram showing a vacuum booster according to the present invention.

Figure 4 shows a check valve provided in the center plate according to the present invention, Figure 4a is a use state showing the check valve in the booster stopped state, Figure 4b is a use showing the check valve in the booster operating state State diagram.

Explanation of symbols on the main parts of the drawings

10: vacuum booster 12: center plate

20: front chamber 22: front housing

24a: front pressure chamber, 24b: front transformer chamber,

26: front support 28: front diaphragm

30: rear chamber 32: rear housing

34a: rear pressure chamber 34b: rear transformer chamber

36: rear support 38: rear diaphragm

40: control valve 50: power piston

60: push rod 70: air valve piston

80a: input shaft 80b: output shaft

90: check valve 91: valve housing (Valve Housing)

92a: Air shutoff hole 92b: Air push rod

92b-1: Air discharge hole 92b-2: Spring support

Claims (1)

Front and rear diaphragms 28 and 38 for partitioning the interior where the front and rear housings 22 and 32 are hermetically coupled into the front positive and transformer chambers 24a and 24b and the rear positive and transformer chambers 34a and 34b, and A front and rear chamber 30 provided with a center plate 12 at a center portion thereof; A control valve (40) and an air valve piston (70) for controlling communication of vacuum or atmosphere to the front and rear chambers (20, 30); In the vacuum booster structure of a brake for a vehicle comprising: a power piston (50) interlocking with the front and rear diaphragms (28, 38), A valve housing (Valve) in which an air flow path (91a) is formed at the center portion so as to communicate the front and rear chambers (20, 30) at a predetermined position of the center plate (12) so as to vacuum the rear chamber (30), which is an atmospheric pressure chamber. Housing, 91, the spring support jaw (91b-1, 91b-2) provided to protrude to one end of the valve housing 91, the left and right by the spring 93 in the air flow path (91a) Air blocking part 92a which is provided to be movable, air discharge hole 92b-1 which is integrally formed with the air blocking part 92a, and penetrated to the upper and lower sides thereof, and a spring recessed into the rear side. A vacuum booster structure for a brake for a vehicle, characterized in that a check valve (90) is formed of an air push rod (92b) provided with a support (92b-2).