KR101868842B1 - Brake booster for vehicle - Google Patents

Abstract

A vehicle brake booster is disclosed. The brake booster for a vehicle according to the present invention is characterized in that an air chamber sealed between a rear end of a plunger and a poppet valve is provided at the time of non-operation of the booster, and the air in the air chamber, And when the input shaft moves over a predetermined section, the atmosphere of the air suction portion flows into the variable pressure chamber through the air chamber.

Description

Brake Booster for Vehicle {BRAKE BOOSTER FOR VEHICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a brake booster for a vehicle, and more particularly, to a brake booster for a vehicle that suppresses a driver's feeling of disturbance and noise during pedal operation.

Generally, a brake booster for a vehicle generates a large braking force with a small force by using a difference in pressure between a vacuum and an atmospheric pressure.

The brake booster includes a valve body provided so as to be slidable in a cell, a static pressure chamber and a variable pressure chamber formed on the front and rear sides of the power piston fixed to the valve body, and a valve mechanism provided in the valve body for switching the flow path, A plunger slidably movable on the valve body, an atmospheric valve seat formed on the plunger, a valve body seated on the vacuum valve seat and the atmospheric valve seat, An air passage communicating with a space inside the atmospheric valve in which the atmospheric valve seat and the valve body are in contact with each other and a space communicating with the space between the vacuum valve and the atmospheric valve, And a variable pressure passage.

In the brake booster, the valve body is seated on the atmospheric valve seat formed on the plunger to shut off the communication between the atmospheric passage and the variable-pressure passage by closing the atmospheric valve, and the vacuum booster is separated from the vacuum valve seat, And the passage and the passage of the change-over passage are communicated. In this state, the static pressure chamber and the variable pressure chamber formed before and after the power piston of the brake booster are in communication with each other through the constant pressure passage and the variable pressure passage, so that no pressure difference acts on the power piston and the valve body and the plunger are stopped have.

On the other hand, at the time of operation of the brake booster, the valve body is separated from the atmospheric valve seat formed on the plunger to open the atmospheric valve, thereby communicating the atmospheric passage and the pressure passage with the vacuum valve seat, closing the vacuum valve, As shown in Fig. In this state, the variable pressure chamber formed behind the power piston of the booster communicates with the atmosphere through the variable pressure passage and the atmospheric passage, so that the pressure difference acts on the power piston, and the valve body advances.

At this time, when the driver presses the brake pedal, the atmosphere is rapidly introduced into the transformer chamber, and the movement of the valve body is accelerated to generate vibration and noise. As a result, a sudden change in force occurs in the pedal connected to the input shaft, there is a problem.

Korea Patent Publication No. 2011-0136914 (published on December 22, 2011)

Embodiments of the present invention are intended to provide a vehicle brake booster capable of reducing noise and heterogeneity in brake operation.

According to one aspect of the present invention, there is provided a poppet retainer for selectively opening and closing a static pressure passage and a variable pressure passage in a valve body for opening and closing communication between a static pressure chamber formed before and after a power piston and a variable pressure chamber, And a plunger which is moved by the input shaft and is in contact with the poppet valve. The brake booster according to any one of claims 1 to 3, The air in the air chamber is first introduced into the variable pressure chamber when the input shaft is moved for a predetermined interval in order to operate the booster, and when the input shaft moves beyond the predetermined section, the air The atmosphere of the suction portion flows into the variable pressure chamber through the air chamber A brake booster can be provided.

Further, the air chamber may be formed by the plunger, the poppet valve, the elastic body, and the poppet retainer so that the tip of the poppet retainer is in pressure contact with the elastic body joined to the plunger rear end.

The outer circumference of the rear end of the plunger may be provided with a recessed portion for engaging the elastic body.

Further, the valve seat is opened when the input shaft is moved over the predetermined section, and between the elastic member and the tip contact portion of the poppet retainer when the input shaft is moved over the predetermined section.

Further, the elastic body includes at least one of rubber and sponge.

The poppet retainer includes a fixed portion fixed to the inner wall of the valve body, a guide portion extending in the axial direction of the valve body to contact the inner diameter of the poppet valve, and a spring support portion connecting the fixed portion and the guide portion And when the booster is not operated, the tip of the guide portion presses the elastic body to depress the elastic body.

The embodiments of the present invention can reduce the noise due to the sudden atmospheric inflow when the booster is operated and eliminate the sense of feeling that the driver feels when operating the brake pedal.

1 is a sectional view showing a vehicle brake booster according to an embodiment of the present invention.
2 is a partially enlarged view of Fig.
3 is an operational state diagram of the valve during booster non-operation according to an embodiment of the present invention.
4 is a view illustrating an operation state of a valve when the input shaft moves in a predetermined section according to an embodiment of the present invention.
5 is a diagram illustrating an operation state of a valve when the input shaft moves over a predetermined interval according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Fig. 1 is a sectional view showing a vehicle brake booster according to an embodiment of the present invention, and Fig. 2 is a partially enlarged view of Fig. 1. Fig.

1 and 2, a vehicle brake booster according to an embodiment of the present invention includes a casing 10 in which a front shell 11 and a rear shell 12 are hermetically sealed, A power piston 41 and a diaphragm 42 which are partitioned into a chamber 20 and a rear variable pressure chamber 30 and a power piston 41 and a diaphragm 42. The power piston 41 and the diaphragm 42 are disposed so as to pass freely, An input shaft 60 for actuating the valve body 50 by operation of the brake pedal and a control valve 60 for controlling the amount of force applied to the variable pressure chamber 30 And an output shaft 70 provided with a reaction disk 71 between itself and the input shaft 60 to receive the output shaft 70.

Here, the pipe 11a installed on the front surface of the casing 10 is connected to an external negative pressure source (such as an intake manifold of a vehicle), so that the static pressure chamber 20 is maintained at a low pressure.

The return spring 13 for restoring the valve body 50 by resiliently supporting the valve body 50 is installed in the static pressure chamber 20.

One end of the valve body 50 is inserted into the center portion of the power piston 41 and the diaphragm 42 to be coupled.

The other end of the valve body 50 passes through the center of the rear shell 12 and forms an air suction part 61 communicating with the outside air.

And the input shaft 60 is located at the center of the air intake portion 61.

The valve body 60 is provided with a constant pressure passage 62 provided so as to allow the constant pressure chamber 20 and the variable pressure chamber 30 to communicate with each other and a variable pressure passage 63 provided so as to allow communication between the variable pressure chamber 30 and the atmosphere , And a cylinder 64 is provided in the central portion once in the axial direction.

 The cylinder 64 is provided with a plunger 65 provided so as to be able to advance and retreat so as to slide in the axial direction in association with the end of the input shaft 60.

The constant pressure chamber 62 communicates with the pressure chamber 20 and the variable pressure chamber 30 while the variable pressure chamber 62 is opened and the variable pressure chamber 63 communicates with the variable pressure chamber 30 with the air suction portion 61 opened .

The plunger 65 is advanced by the input shaft 60 during braking and the forwardly operated input shaft 60 is returned to the rear side through the resilient restoring force of the first spring 66 when the brake is released.

The first spring 66 is supported in a poppet retainer 100 having a truncated cone shape and supported at the outer surface of the input shaft 60 whose rear end is formed with a stepped portion and whose tip end is coupled to the inside of the valve body 50.

The valve body 50 is provided with a poppet valve 80 for controlling the inflow of air by the operation of the input shaft 60 toward the inner wall of the air intake portion 61 surrounding the input shaft 60.

The poppet valve 80 is made of an elastic material and is provided in a ring shape so as to be movable forward and backward along the longitudinal direction of the input shaft 60.

The poppet valve 80 includes an inner sealing lip 81 on the inner diameter side, an outer sealing lip 82 on the outer diameter side, and a body 83 connecting the inner sealing lip 81 and the outer sealing lip 82 .

The poppet valve 80 is firmly fixed to the air suction portion 61 by the poppet retainer 100 and the front end of the poppet valve 80 selectively opens and closes the constant pressure passage 62 and the variable passage 63 in accordance with the operation of the input shaft 60 do.

A first valve seat 91 is provided on the inner wall of the valve body 50 so as to perform a vacuum valve function in combination with the tip of the poppet valve 80 so that the tip of the poppet valve 80 is seated on the first valve seat 91 The positive pressure passage 62 is closed.

The second valve seat 92 is provided at the rear end of the plunger 65 so as to perform an air valve function in combination with the front end of the poppet valve 80. The front end of the poppet valve 80 is connected to the second valve seat 92 The pressure change passage 63 is closed and the communication between the atmosphere and the pressure change chamber 30 is cut off.

The poppet valve 80 is elastically supported toward the first valve seat 91 and the second valve seat 92 through the second spring 67 provided at the rear.

The poppet retainer 100 is provided so as to surround the inner diameter side and the rear side of the poppet valve 80.

The poppet retainer 100 includes a guide portion 101 extending in the axial direction of the valve body 50 on the inner diameter side of the poppet valve 80 to guide the inner sealing lip 81 in operation of the poppet valve 80, A spring supporting portion 102 extending vertically from the guide portion 101 to support the rear end of the spring 67 and a fixing portion 103 provided at the end of the spring supporting portion 102 to be fixed to the inner wall of the valve main body 50, .

A mounting groove 103a is formed in the fixing portion 103 for sealing between the poppet retainer 100 and the inner wall of the valve body 50 and a sealing member 120 is mounted on the mounting groove 103a.

The outer sealing lip 82 of the poppet valve 80 is guided to the inner wall of the valve body 50 facing the guide portion 101 of the poppet retainer 100 during operation of the poppet valve 80, 66 are provided so as to be supported by the poppet retainer 100 between the spring support portion 102 and the fixing portion 103.

3, an elastic body 210 for forming an air chamber 200, which is hermetically sealed inside the second valve seat 92 (radially inward of the plunger) when the booster is not operated, is provided at the rear end of the plunger 65, .

The elastic body 210 has an elastic material such as rubber, sponge or the like and may be supported in a receiving portion 220 provided in a ring shape and recessed on the outer periphery of the rear end of the plunger 65.

The contact portion 104 formed at the tip end of the poppet retainer 100, that is, at the tip of the guide portion 101 when the booster does not operate, presses one side of the elastic body 210 to depress the elastic body 210 to a predetermined depth, The communication between the suction portion 61 and the air chamber 200 is cut off.

The air chamber 200 can be formed as a closed space formed by the plunger 65, the poppet valve 80, the elastic body 210, and the guide portion 101 of the poppet retainer 100. The volume of the air chamber 200 can be appropriately changed according to the design conditions of the initial air inflow amount of the booster.

With this configuration, the poppet valve 80 is brought into contact with the second valve seat 92 of the plunger 65 by the resilient force of the second spring 67 in the non-operating state of the booster, The contact portion 104 formed at the front end of the poppet retainer 100 blocks the communication between the air chamber 200 and the air suction portion 61 by pressing the elastic body 210 and depressing the elastic body 210 to a predetermined depth. Thereby interrupting the communication.

The plunger 65 is pushed toward the reaction disc 71 and the second valve seat 92 is pushed downward by a predetermined distance (approximately 0.2 to 0.5 mm) when the driver steps on the brake pedal, And the front end of the poppet valve 80 are spaced apart and the variable-pressure passage 63 is opened. The elastic body 210 and the contact portion 104 of the poppet retainer 100 are in contact with each other without falling and the communication between the air chamber 200 and the air suction portion 61 is blocked. Therefore, the air filled in the air chamber 200 through the gap between the second valve seat 92 and the front end of the poppet valve 80 is first introduced into the variable pressure passage 63.

5, when the input shaft 60 advances by more than a predetermined interval, the elastic body 210 and the contact portion 104 of the poppet retainer 100 are separated from each other so that the air chamber 200 and the air suction portion 61 are communicated with each other The atmosphere of the air suction unit 61 is introduced into the variable pressure chamber 30 through the air chamber 200 and the pressure communication path 63.

Therefore, when the booster is initially operated, a large amount of air is suddenly introduced into the variable pressure passage 63, thereby reducing the vibration and noise caused by the movement of the valve body 50. In addition, the sudden force of the pedal connected to the input shaft 60 So that it is possible to reduce the sense of heterogeneity felt by the driver. In addition, since the air chamber 200 is always filled with the constant air, it is possible to provide the driver with a constant pedal feeling during the initial operation.

The foregoing has shown and described specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims.

20: static pressure chamber, 30: variable pressure chamber,
41: power piston, 50: valve body,
60: input shaft, 61: air intake portion,
62: static pressure passage, 63: variable passage passage,
65: plunger, 70: output shaft,
80: poppet valve, 91: first valve seat,
92: second valve seat, 100: poppet retainer,
101: guide portion, 104: contact portion,
200: air chamber, 210: elastic body,
220: Reception area.

Claims (6)

A poppet valve supported by a poppet retainer provided on an air intake portion inside the valve body to selectively open and close a static pressure passage and a variable pressure passage in the valve body for opening and closing communication between the static pressure chamber and the variable pressure chamber formed before and after the power piston, And a plunger provided with a valve seat in contact with the poppet valve, the brake booster comprising:
An air chamber sealed between the rear end of the plunger and the poppet valve when the booster is not operated is sealed inside the valve seat,
The air in the air chamber is first introduced into the variable pressure chamber when the input shaft moves a predetermined distance in order to operate the booster, and when the input shaft moves beyond the predetermined section, Brake booster for automobile. The method according to claim 1,
Wherein the air chamber is formed by the plunger, the poppet valve, the elastic body, and the poppet retainer by allowing the tip end of the poppet retainer to come into pressure contact with the elastic body joined to the plunger rear end. 3. The method of claim 2,
And a recessed portion for engaging the elastic body is provided on the outer periphery of the rear end of the plunger. 3. The method of claim 2,
Wherein the valve seat is opened when the input shaft is moved over the predetermined interval,
And when the input shaft is moved over the predetermined section, the elastic body and the tip contact portion of the poppet retainer are opened. 3. The method of claim 2,
Wherein the elastic body comprises at least one of rubber and sponge. 3. The method of claim 2,
The poppet retainer includes a fixed portion fixed to the inner wall of the valve body, a guide portion extending in the axial direction of the valve body and contacting the inner diameter of the poppet valve, and a spring support portion connecting the fixed portion and the guide portion ,
And the tip of the guide portion presses the elastic body to depress the elastic body when the booster is not operated.

Images