KR20090106088A - Panic assist booster for a vehicle - Google Patents

Abstract

PURPOSE: A panic assist booster for a vehicle is provided to improve the quality of a product by smoothly inserting a ball bearing into a groove for a ball bearing. CONSTITUTION: A panic assist booster(200) for a vehicle comprises an air valve, a power piston, a plunger, a sleeve, a retainer, a contact spring, and a sleeve spring. In the air valve(208), a first support part and a second support part(205,206) are protruded in the columnar direction. An insertion groove is formed to insert the columnar direction inside the air valve. A cylinder part is formed inside the power piston to insert the air valve inside. The plunger has a first end part and a second end part which are formed at the both ends. A groove for the ball bearing is formed in the plunger to mount the ball bearing on the fixed position. The groove for the ball bearing(226) is formed inside the sleeve(220). The retainer(235) is coupled on the groove for the retainer. The contact spring is equipped between the front surface and the power piston of the sleeve protrusion.

Description

Panic assist booster for a vehicle}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle panic assist booster for obtaining a higher output performance in emergency panic operation and reducing the reaction force applied to the driver, unlike in normal operation, in particular an operation joint generated during panic operation. It relates to the configuration of the air valve and the sleeve of the vehicle panic assist booster that can be prevented.

As the technology of automobiles has developed rapidly, the speed of automobiles has been continuously increased, and the weight of automobiles has been gradually increased due to the increase of internal and external parts. As a result, the inertial force of automobiles has been increased not only by the synergistic effect of mass and acceleration, but also the interest in safety while driving.

As a result, various researches and developments have been made to improve the braking performance of automobiles, and as a result of these efforts, the recent rapid development is the booster of brake.

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 described above is largely based on a booster that doubles the pedaling force of the brake pedal by using a vacuum pressure (engine suction pressure) generated by engine power and a force doubled by the booster. Accordingly, it is composed of 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 the negative pressure of the engine intake manifold and an air type using the pressure provided from a compressor driven by the engine, and a vacuum type is generally used in a small vehicle.

1 is a view schematically showing a vehicle panic booster according to the prior art, and FIG. 2 is a cross-sectional view schematically showing an enlarged power supply apparatus of a vehicle panic booster according to the prior art.

As shown in the figure, the vehicle panic booster 10 according to the prior art is composed of a front housing 30 which is a vacuum chamber and a rear housing 20 which is an atmospheric pressure chamber, and the front housing 30 and the rear housing ( 20) a control valve 130 that controls the communication of vacuum or atmosphere to the air and a push rod that transmits the pedal force applied to the air valve 16 and the power piston 14 and the brake pedal B / P. 15) and the like.

Here, the front forward / transformer chamber and the rear forward / transformer chamber constituting the front and rear chambers 11 and 12 are partitioned by a front diaphragm and a rear diaphragm, and the front and rear diaphragms are supported by respective front and rear supports. It is.

In addition, the control valve 13 is coupled to the front diaphragm and the front support, the center plate and the rear diaphragm and the rear support at one end portion, and the other end formed with the air suction portion communicates with the atmosphere through the center of the rear cell. . In addition, a positive pressure passage is formed between the front and rear constant pressure chambers and the front and rear transformer chambers, and a transformer passage is formed to communicate the atmosphere with the front and rear transformer chambers. In addition, an air valve 16 sliding in the axial direction with an end of the input shaft is installed in the control valve 13, one end of the air valve 16 and one end of the control valve 13 are output shafts. It is in contact with the reaction disk 18 provided at the end.

Hereinafter, the operation of the brake booster 10 according to the related art configured as described above will be briefly described.

First, in the rest state of the booster 10 before the driver presses the brake pedal, the control valve 13 comes into contact with the air valve 16. At this time, the control valve 130 and the power are controlled. A predetermined gap is formed between the pistons 14.

In this state, a negative pressure acts on the front chamber 11 from an intake manifold (not shown), and the negative pressure is transmitted to the rear chamber through a gap between the power piston 14 and the control valve 13. At this time, the front and rear chambers divided forward and backward by the center plate are in a negative pressure state, and the front and rear diaphragms are held at the stop position by the elasticity of the return spring.

When the driver presses the brake pedal, the booster 10 is in an initial apply state. At this time, the control valve 13 is pushed forward by a pressure spring (not shown), thereby providing an air valve piston 16. ) Is kept in close contact with the power piston 14 while maintaining contact with), and the vacuum negative pressure applied to the rear chamber is short-circuited. At this time, when the push rod 15 is slightly advanced to move the air valve piston 16 forward, a slight gap is generated between the power piston 14 and the air valve piston 16, thereby boosting the booster 10. Reaches a partial braking state.

Accordingly, the negative pressure acts on the front chamber and the atmospheric pressure acts on the rear chamber, but the pressure difference between the front chamber, which is the vacuum chamber, and the rear chamber, which is the atmospheric chamber, is not large, so that the diaphragm is slightly pushed toward the front chamber and gradually compresses the return spring. At this time, the rod piston is advanced as much as the return spring is compressed to apply a braking force to the master cylinder.

Further, when the push rod 15 is pushed in such that the air valve piston 16 is in contact with the rod piston, the air valve piston 16 is completely removed from the control valve 13 keeping in close contact with the power piston 14. It will fall off and become a full braking state. At this time, the front chamber, which is a vacuum chamber, is kept closed in a negative pressure state, and the rear chamber, which is an atmospheric pressure chamber, is completely opened and becomes an atmospheric pressure state, so the pressure difference between the front and rear chambers is maximum. As a result, the front and rear diaphragms are advanced as far forward as possible and the return spring is completely compressed. In the above process, the driver's brake pedal input is boosted, and when the brake pedal is further depressed, the driver's input is directly acted on the master cylinder by the push rod 15.

As a result, the force generated by the pressure difference acts in a direction from the larger pressure to the smaller one, and the control valve 13 interlocked with the front and rear diaphragms and the power piston 14 is a force generated by the pressure difference. The reaction disk 18 is pushed through the center of the control valve 13 by moving toward the front and rear constant pressure chambers.

 At this time, the reaction disk 18 acts by the force applied from the plunger tip and the force applied from the control valve 13. At this time, the power ratio generated by the driver and the pressure difference applied by the driver results in a ratio of the center area of the output shaft that is in contact with the area ratio of the tip of the reaction disk 18.

However, when the driver's stepping force on the brake pedal (B / P) is more than a certain level, the additional power loss is lost, and the stepping force of the brake pedal (B / P) is transmitted as it is. do.

However, the conventional booster 10 may not have enough output compared to the driver's brake pedal (B / P) input in a panic braking situation requiring emergency braking, and thus the braking force may be insufficient, resulting in a long braking distance and an accident. There was a problem that could be followed.

Accordingly, the present applicant has filed an invention for a panic assist booster for automobiles that solves the problems of the prior art panic booster as described above through Korean Patent Application No. 2007-116598 (filed Nov. 12, 2007).

If briefly described the basic configuration of the automotive panic assist booster described in the patent application No. 2007-116598 as follows.

3 and 4, the vehicle panic assist booster 100 according to the patent application No. 2007-116598, the push rod 128 to operate in front and rear in conjunction with a brake pedal (not shown) The first support portion 105 and the second support portion 106 protrude in the circumferential direction at a position spaced apart from the outside, and the insertion groove into which the plunger spring 124 can be inserted is formed, And an air valve 108 through which the ball bearing hole 141 is formed so that the ball bearing 126 is coupled to a corresponding position of the lower portion.

In addition, a cylinder-shaped cylinder part 123 is formed therein so that the air valve 108 is inserted therein, and one side of the air valve 108 includes a standby chamber 107, and the other side of the variable chamber ( 173, and the tip includes a power piston 101 that is bent inward to further form a plunger passage 127.

In addition, the ball bearing 126 includes a first end portion 102 and a second end portion 103 protruding from both ends, and the ball bearing 126 is seated at an outer predetermined position spaced apart from the first end portion 102. The groove 133 is formed, and includes a plunger 130 that makes a relative motion inside the air valve 108.

The ball bearing groove 138 is coupled to the outside of the front end of the air valve 108 and the ball bearing 126 is inserted therein, and the sleeve protrusion 121 protrudes outward at a predetermined position. A sleeve 120.

In addition, a retainer 135 is coupled to the retainer groove 140 formed outside the front end of the air valve 108 to support the sleeve 120.

A contact spring 119 provided between the front surface of the sleeve protrusion 121 and the power piston 101, and a sleeve spring provided between the rear surface of the sleeve protrusion 121 and the air valve 108. 139, including.

In addition, a retainer fixing groove 129 is further formed in the circumferential direction on the inner surface of the first end portion 109 formed at one side of the air valve 108 to which the front end of the push rod 128 is coupled. By further including a push rod retainer (not shown) for fixing the push rod 128 in the fixing groove 129, it is possible to prevent the push rod 128 from being separated.

A rear bearing 112 including a power piston support portion 113 protruding to support the power piston 101 is provided outside one end of the power piston 101 to thereby provide the power piston 101. Robust support prevents errors during operation, extending the life of the product.

Accordingly, the automobile panic assist booster 100 described in Patent Application No. 2007-116598 has the push rod 128 momentarily rapidly advancing the air valve 108 at the time of sudden braking, and relatively the power piston 101. ) Is not moved.

In this case, the ball bearing 126 provided in the ball bearing hole 141 of the air valve 108 in accordance with the movement of the sleeve 120 and the air valve 108 supported by the sleeve spring 139. ) Is separated by a force applied to the outer surface of the plunger 130 by the reaction force of the reaction disk 115 is inserted into the groove for the ball bearing 138 provided in the sleeve 120.

Thus, as the plunger 130 moves into the space between the air valve 108 and the plunger 130, the reaction gap 153 is increased to generate the output required for rapid braking.

In addition, since the plunger 130 must be restored to an initial position when the brake is released, a plunger spring 124 for pushing the plunger 130 from the inside of the air valve 108 is provided with the plunger 130 and the air. It is provided inside the valve 108.

Therefore, the vehicle panic assist booster described in Patent Application No. 2007-116598 having the above structure obtains a higher output performance during the panic operation unlike in the normal operation, so that the brake applied to the elderly or the weak female driver. The reaction force is effectively reduced so that an effective braking operation can be performed with a small force.

That is, in the normal operation, the ball bearing 126 is located in the ball bearing hole 141 of the air valve 108, while in the panic operation, the relative position of the sleeve 120 and the air valve 108 The ball bearing 126 is coupled to the ball bearing groove 138 of the sleeve 120 such that the plunger 130 moves to the air valve 108 and comes into contact with the plunger spring 124. It is pushed by the elastic force of) and it is virtually impossible to move to the air valve 108 anymore.

This means that the reaction force transmitted to the driver through the plunger 130 is reduced.

However, the vehicle panic assist booster described in Patent Application No. 2007-116598 as described above realizes higher output performance during panic operation and reduces the reaction force applied to the driver, thereby reducing the responsiveness of the elderly and the weak female driver. It can output the effective braking force alone, and can overcome the limitation of shortening the braking distance due to lack of braking force in case of an emergency, so that the effect of improving the output performance in case of emergency braking can be sufficiently exerted, but the ball bearing of the air valve 108 Operation joint by collision between the ball bearing 126 and the ball bearing groove 138 in the process of inserting the ball bearing 126 seated in the hole 141 into the ball bearing groove 138 provided in the sleeve 120. There is a disadvantage that this occurs.

Therefore, in the recent automobile market, where consumer's emotional quality is very important, it is required to provide a vehicle panic assist booster that can suppress not only braking performance but also occurrence of operation joints.

The present invention provides a ball bearing and a ball bearing groove in a process in which a panic assist booster for automobile described in Patent Application No. 2007-116598 is inserted into a ball bearing groove provided in a sleeve when a ball bearing seated in a ball bearing hole of an air valve is operated during a panic operation. It was devised to solve the problem of the operation joint caused by the collision between the vehicle, and it is possible to suppress the operation joint generated during the operation of the panic while maintaining the improved braking performance of the automotive panic assist booster of Patent Application No. 2007-116598. It is an object of the present invention to provide a car panic assist booster.

The first embodiment of the present invention for achieving the above object,

In contact with the front end of the push rod operating in conjunction with the brake pedal, the first support portion and the second support portion protrude in the circumferential direction at the outer spaced apart position, the inner side is formed with an insertion groove for inserting the plunger spring An air valve having a ball bearing hole formed therein so that the ball bearing is coupled to a corresponding position of an upper portion and a lower portion thereof, the ball bearing hole having a conical truncated shape whose diameter at an outer surface is larger than a diameter at an inner surface;

A cylinder-shaped cylinder part is formed therein so that the air valve is inserted into the inside, and one side of the air valve includes a standby chamber, the other side includes a variable chamber, and the tip is bent inward to further form a plunger passage. piston;

A plunger including a first end portion and a second end portion protruding at both ends, and having a ball bearing groove for seating the ball bearing at an outer predetermined position spaced apart from the first end portion, the plunger having a relative motion inside the air valve;

A sleeve which is coupled to the outside of the front end of the air valve and has a ball bearing groove formed therein for inserting a ball bearing therein, and protrudes a sleeve protrusion at an outer predetermined position;

A retainer coupled to a retainer groove formed outside the tip of the air valve to support the sleeve;

A contact spring provided between the front face of the sleeve protrusion and the power piston; And

A sleeve spring provided between the rear surface of the sleeve protrusion and the air valve;

It is made, including.

In addition, a second embodiment of the present invention for achieving the above object,

In contact with the front end of the push rod operating in conjunction with the brake pedal, the first support portion and the second support portion protrude in the circumferential direction at the outer spaced apart position, the inner side is formed with an insertion groove for inserting the plunger spring An air valve having a ball bearing hole formed therethrough so that the ball bearing is coupled to a corresponding position of an upper portion and a lower portion thereof, the ball bearing hole being inclined in a direction toward the reaction disc;

A cylindrical cylinder portion is formed therein so that the air valve is inserted inward, and one side of the air valve includes a standby chamber, the other side includes a variable chamber, and a front end is bent inward to further form a plunger passage. ;

A plunger including a first end portion and a second end portion protruding at both ends, and having a ball bearing groove for seating the ball bearing at an outer predetermined position spaced apart from the first end portion, the plunger having a relative motion inside the air valve;

A sleeve which is coupled to the outside of the front end of the air valve and has a ball bearing groove formed therein for inserting a ball bearing therein, and protrudes a sleeve protrusion at an outer predetermined position;

A retainer coupled to a retainer groove formed outside the tip of the air valve to support the sleeve;

A contact spring provided between the front face of the sleeve protrusion and the power piston; And

A sleeve spring provided between the rear surface of the sleeve protrusion and the air valve;

It is made, including.

A round portion may be further included on a boundary line formed between the groove for the ball bearing and the inner surface of the sleeve.

The panic assist booster for automobiles according to the first and second embodiments of the present invention allows the ball bearing to be smoothly inserted into the groove for the ball bearing, such that the ball bearing and the groove for the ball bearing are mutually inserted as the ball bearing is rapidly inserted into the groove for the ball bearing. It is possible to effectively prevent the operation joint caused by the strong collision, and finally has the effect of improving the emotional quality of the product.

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

FIG. 5 is an enlarged cross-sectional view schematically illustrating a stop state of the vehicle panic assist booster according to the first embodiment of the present invention, and FIG. 6 is an intermediate state in which the panic assist booster for automobiles according to the first embodiment of the present invention operates. 7 is an enlarged cross-sectional view schematically illustrating a stop state of a panic assist booster for a vehicle according to a second exemplary embodiment of the present invention.

As shown in the figure, the vehicle panic assist booster 200 according to the first embodiment of the present invention,

The first support part 205 and the second support part 206 protrude in the circumferential direction in contact with the tip of the push rod 228 which operates in front and rear in conjunction with a brake pedal (not shown). And an air valve 208 having an insertion groove formed therein into which the plunger spring 224 can be inserted and through which the ball bearing hole 241 is formed so that the ball bearing 226 is coupled to a corresponding position of the upper and lower portions thereof. .

Here, the shape of the ball bearing hole 241 formed through the air valve 208 has a conical truncated shape whose diameter at the outer surface of the air valve 208 is relatively larger than the diameter at the inner surface. . That is, the cross-sectional shape of the ball bearing hole 241 has a trapezoidal shape longer than the lower surface side of the air valve 208, and thus the diameter at the outer surface of the air valve 208 of the ball bearing hole 241 Is larger than the diameter of the ball bearing 226.

In addition, a cylinder-shaped cylinder part 223 is formed therein so that the air valve 208 is inserted into the inside, and one side of the air valve 208 has a standby chamber 207 and the other side has a variable chamber 273. The tip includes a power piston 201 which is bent inward to further form a plunger passage 227.

In addition, the ball bearing 226 includes a first end portion 202 and a second end portion 203 protruding from both ends, and the ball bearing 226 is seated at an outer predetermined position spaced apart from the first end portion 202. The groove 233 is formed, and includes a plunger 230 that makes a relative movement inside the air valve 208.

In addition, a ball bearing groove 238 is coupled to the outside of the front end of the air valve 208 and the inside of the ball bearing 226 is inserted into the ball bearing 226 during the panic operation, and the sleeve protrusion 221 protrudes at an outer predetermined position. A hollow cylindrical sleeve 220 is formed.

And it includes a retainer 235 coupled to the retainer groove 240 formed outside the front end of the air valve 208 to support the sleeve 220.

In addition, a contact spring 219 provided between the front surface of the sleeve protrusion 221 and the power piston 201, and a sleeve spring provided between the rear surface of the sleeve protrusion 221 and the air valve 208 ( 239).

A retainer fixing groove 229 is further formed in an inner surface of the first end portion 209 formed at one side of the air valve 208 to which the front end of the push rod 228 is coupled, and the retainer is fixed. By further providing a push rod retainer (not shown) for fixing the push rod 228 to the dragon groove 229, it is possible to prevent the push rod 228 from being separated.

A rear bearing 112 including a power piston support 213 protruding to support the power piston 201 is provided outside the one end of the power piston 201 to thereby provide the power piston 201. Robust support prevents errors during operation, extending the life of the product.

Accordingly, in the vehicle panic assist booster 200 according to the first embodiment of the present invention, the push rod 228 momentarily rapidly advances the air valve 208 during rapid braking, and relatively the power piston 201. ) Is not moved.

At this time, the ball bearing 226 provided in the ball bearing hole 241 of the air valve 208 according to the movement of the sleeve 220 and the air valve 208 supported by the sleeve spring 239. ) Is separated by the force applied to the outer surface of the plunger 230 by the reaction force of the reaction disk 215 is inserted into the groove for the ball bearing 238 provided in the sleeve 220.

Thus, as the plunger 230 moves into the space between the air valve 208 and the plunger 230, the reaction gap 253 is increased to generate the output required for rapid braking.

In particular, when the ball bearing 226 according to the first embodiment of the present invention is inserted into the ball bearing groove 238 provided in the sleeve 220, the ball bearing hole 241 is formed through the air valve 208. Since the diameter at the outer surface of the air valve 208 has a conical truncated shape relatively larger than the diameter at the inner surface, even before the ball bearing groove 238 is completely opened with respect to the ball bearing 226, As the ball bearing 226 enters the ball bearing groove 238, the ball bearing 226 is rapidly inserted into the ball bearing groove 238, so that the ball bearing 226 and the ball bearing groove 238 strongly enter each other. It is possible to effectively prevent the operation joint caused by the collision (see Fig. 6).

In addition, if the ball bearing groove 238 and the round portion 222 connecting the boundary line formed between the inner surface of the sleeve 220 to the smooth curved surface is included in the ball bearing groove 238, the insertion process of the ball bearing 226 is further It is more preferable to make it smooth so that the occurrence of the operation joint can be prevented more effectively.

In addition, since the plunger 230 must be restored to the initial position when the brake is released, a plunger spring 224 for pushing the plunger 230 from the inside of the air valve 208 is provided with the plunger 230 and the air. It is provided inside the valve 208.

Therefore, the vehicle panic assist booster described in Patent Application No. 2007-116598 having the above structure obtains higher output performance during panic operation unlike in normal operation, and therefore is applied to the elderly or weak female driver. The brake reaction force is effectively reduced, enabling effective braking operation even with small forces.

That is, in the normal operation, the ball bearing 226 is located in the ball bearing hole 241 of the air valve 208, while in the panic operation, the relative position of the sleeve 220 and the air valve 208 The ball bearing 226 is coupled to the ball bearing groove 238 of the sleeve 220 such that the plunger 230 moves to the air valve 208 to be in contact with the plunger spring 224. It is pushed by the elastic force of) and it is virtually impossible to move to the air valve 208 side anymore.

This means that the reaction force transmitted to the driver through the plunger 230 is reduced.

7 is an enlarged cross-sectional view schematically illustrating a stopped state of the vehicle panic assist booster 200 ′ according to the second embodiment of the present invention.

Most of the configuration of the second embodiment of the present invention is the same as that of the first embodiment, except that the shape of the ball bearing hole 241 'formed through the air valve 208 is different.

That is, according to the second embodiment of the present invention, the ball bearing hole 241 'is maintained while the shape of the ball bearing hole 241' is equal to the diameter at the outer surface of the air valve 208 and the diameter at the inner surface thereof. ) Is characterized by having a slope. Here, the inclination direction of the ball bearing hole 241 ′ is configured to be inclined in the direction toward the reaction disk 215, which is the ball bearing (B) in the process of restoring the plunger 230 to the initial position when the brake is released. 226 is to return smoothly to the initial state, that is, the ball bearing 226 is seated in the ball bearing groove 233 formed in the air valve 208.

According to the second embodiment of the present invention, since the ball bearing hole 241 'is configured to be inclined toward the reaction disk 215, the ball bearing 226 may smoothly enter the ball bearing groove 238. Thus, as the ball bearing 226 is rapidly inserted into the ball bearing groove 238, the ball bearing 226 and the ball bearing groove 238 can be effectively prevented from operating joint generated by the strong collision with each other.

In addition, the second embodiment of the present invention also forms a round portion 222 on the boundary line formed between the inner surface of the ball bearing groove 238 and the sleeve 220, so that the insertion process of the ball bearing 226 can be made more smoothly. The point is the same.

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to such specific embodiments, and those skilled in the art are appropriate within the scope described in the claims of the present invention. It will be possible to change.

1 is a plan view schematically showing a panic booster for a vehicle according to the prior art,

2 is an enlarged cross-sectional view of "A" in FIG. 1,

3 is an enlarged cross-sectional view schematically showing a vehicle panic assist booster according to Patent Application No. 2007-116598;

4 is an exploded view and a cross-sectional view schematically showing the plunger, sleeve and air valve of FIG.

5 is an enlarged cross-sectional view schematically showing a stopped state of a vehicle panic assist booster according to a first embodiment of the present invention;

6 is an enlarged cross-sectional view schematically showing an intermediate state in which the panic assist booster for a vehicle according to the first embodiment of the present invention operates;

FIG. 7 is an enlarged cross-sectional view schematically illustrating a stopped state of a vehicle panic assist booster according to a second embodiment of the present invention; FIG.

<Brief description of symbols for the main parts of the drawings>

200, 200 ': panic assist booster 201: power piston

202: first end 203: second end

205: first support portion of the air valve 206: second support portion of the air valve

207: atmospheric chamber 208: air valve

212: rear bearing 213: power piston support

215: reaction disk 219: contact spring

220: sleeve 221: sleeve protrusion

222: round part 223: cylinder part

224: plunger spring 226: ball bearing

228: push rod 229: push rod retainer fixing groove

230: Plunger 233: groove for ball bearing

235: retainer 238: groove for ball bearing

239: sleeve spring 240: groove for retainer

241, 241 ': Ball bearing hole 253: Reaction gap

273: variable chamber

Claims (3)

In contact with the front end of the push rod operating in conjunction with the brake pedal, the first support portion and the second support portion protrude in the circumferential direction at the outer spaced apart position, the inner side is formed with an insertion groove for inserting the plunger spring An air valve having a ball bearing hole formed therein so that the ball bearing is coupled to a corresponding position of an upper portion and a lower portion thereof, the ball bearing hole having a conical truncated shape whose diameter at an outer surface is larger than a diameter at an inner surface; A cylindrical cylinder portion is formed therein so that the air valve is inserted into the inside, and one side of the air valve includes a standby chamber, the other side includes a variable chamber, and a tip is bent inward to further form a plunger passage. ; A plunger including a first end portion and a second end portion protruding at both ends, and having a ball bearing groove for seating the ball bearing at an outer predetermined position spaced apart from the first end portion, the plunger having a relative motion inside the air valve; A sleeve which is coupled to the outside of the front end of the air valve and has a ball bearing groove formed therein for inserting a ball bearing therein, and protrudes a sleeve protrusion at an outer predetermined position; A retainer coupled to a retainer groove formed outside the tip of the air valve to support the sleeve; A contact spring provided between the front face of the sleeve protrusion and the power piston; And A sleeve spring provided between the rear surface of the sleeve protrusion and the air valve; Car panic assist booster made, including. In contact with the front end of the push rod operating in conjunction with the brake pedal, the first support portion and the second support portion protrude in the circumferential direction at the outer spaced apart position, the inner side is formed with an insertion groove for inserting the plunger spring An air valve having a ball bearing hole formed therethrough so that the ball bearing is coupled to a corresponding position of an upper portion and a lower portion thereof, the ball bearing hole being inclined in a direction toward the reaction disc; A cylindrical cylinder portion is formed therein so that the air valve is inserted into the inside, and one side of the air valve includes a standby chamber, the other side includes a variable chamber, and a tip is bent inward to further form a plunger passage. ; A plunger including a first end portion and a second end portion protruding at both ends, and having a ball bearing groove for seating the ball bearing at an outer predetermined position spaced apart from the first end portion, the plunger having a relative motion inside the air valve; A sleeve which is coupled to the outside of the front end of the air valve and has a ball bearing groove formed therein for inserting a ball bearing therein, and protrudes a sleeve protrusion at an outer predetermined position; A retainer coupled to a retainer groove formed outside the tip of the air valve to support the sleeve; A contact spring provided between the front face of the sleeve protrusion and the power piston; And A sleeve spring provided between the rear surface of the sleeve protrusion and the air valve; Car panic assist booster made, including. The method according to claim 1 or 2, And a round portion formed on a boundary line formed between the ball bearing groove and the inner surface of the sleeve.

Images