KR200286156Y1 - Power boosting device for vehicle brake - Google Patents

Abstract

The present invention relates to a power boosting device for a vehicle brake, and its purpose is to reduce the overall operating noise by improving the outer circumferential surface of the plunger which is slidably mounted at the front end of the valve body to perform a valve function so that the air inflow resistance is reduced.

The rear brake 62 of the plunger 60 is provided with a second valve seat 63 at the end of the vehicle brake booster according to the present invention so that the front end of the poppet valve 50 is selectively seated to perform an air valve function. The outer circumferential surface was constituted by the inclined surface 65 in the same manner as the inflow direction of air.

Therefore, when the braking action is smoothly guided to the transformer chamber 15 through the inclined surface 65 of the rear end 62 of the plunger 60, there is an advantage that the suction noise due to reduced inflow resistance is reduced.

Description

Power boosting device for vehicle brake

The present invention relates to a power booster for a vehicle brake, and more particularly, to a plunger of the power booster to control the inflow of air is provided so that the front end of the poppet valve is seated inside the valve body.

BOOSTER of a vehicle brake is a device that generates a large braking force with a small force by using a pressure difference between the vacuum and the atmosphere. As shown in Figs. 1 and 2, the power supply device having such a function includes a casing 1 composed of a front cell 1a and a rear cell 1b, an input shaft 3 interlocked by a brake pedal (not shown), It consists of an output shaft (4) and the like receiving the force of displacement in accordance with the operation of the input shaft (4).

The casing 1 is divided into a positive pressure chamber 1f and a transformer chamber 1e by a diaphragm 1c and a power piston 1d. The positive pressure chamber 1f and the transformer chamber 1e are valves described later. It communicates with the positive pressure passage 2e formed in the main body 2. As shown in FIG. One outer wall of the constant pressure chamber 1f is coupled with a negative pressure inlet pipe 1g such as an intake manifold (MANIFOLD) which communicates the inside with a negative pressure source (not shown), and a restoring spring 1h inside the positive pressure chamber 1f. This diaphragm 1c and the power piston 1d are held in the rearward position by the elastic restoring force when the power supply device is in an inoperative state.

And the valve body (2) for controlling the intake of air is coupled to the casing (1), which is fixed to the diaphragm (1c) and the power piston (1d), the rear end is formed with the air inlet (2a) casing (1) It protrudes outward from the rear end of the c) and communicates with the atmosphere. Reference numerals 2b and 2c indicate a silencer that reduces noise and a filter that prevents the introduction of foreign matter.

On the other hand, the plunger 6 which slides in the axial direction at the front-end | tip part of the valve body 2 is provided. The rear end 6b of the plunger 6 is coupled to an end of the input shaft 3 coupled with a brake pedal (not shown) through a seating recess 6d recessed to a predetermined depth, the front end 6a of which is output shaft. Combined with (4). A reaction disc 4a is provided between the output shaft 4 and the tip portion 6a of the plunger 6 to double the force applied due to the difference in cross-sectional area and to transmit it to the output shaft 4.

An inside of the valve body 2 is provided with an elastic poppet valve 5 having a front end contacting the rear end 6b of the plunger 6 to control the inflow of air, and the rear end of the poppet valve 5 is provided with a valve. It is firmly fixed to the inner peripheral surface of the main body 2. A spring 3a is installed between the poppet valve 5 and the support protrusion 3b provided on the outer circumferential surface of the input shaft 3 to support the input shaft 3 backward. Reference numeral 2e is a positive pressure passage formed in the valve body 2 to provide communication between the constant pressure chamber 1f and the transformer chamber 1e, and 2f is between the transformer chamber 1e and the inside of the valve body 2. A transformer passage that provides communication.

On the inner circumferential surface of the valve body 2, the tip of the poppet valve 5 is selectively seated by the operation of the input shaft 3 to close the constant pressure passage 2e, i.e., the first valve seat portion 2d. Is formed, the poppet valve 5 and the first valve seat portion 2d combine to form a vacuum valve. In addition, the rear end portion 6b of the plunger 6 is also provided with a second valve seat portion 6c for selectively seating the front end portion of the poppet valve 5 to control the opening of the transformer passage 2f. (5) and the second valve seat portion 6c combine to perform an air valve function. Accordingly, when the tip portion of the poppet valve 5 is seated on the second valve seat portion 6c, the air of the outside air cannot be introduced by the air valve.

Next, the operation of the conventional vehicle brake booster configured as described above will be described.

First, in the initial state, the positive pressure chamber 1f and the transformer chamber 1e are in a vacuum state by a negative pressure source (not shown). In such a vehicle, when the driver presses a brake pedal (not shown), the input shaft 3 moves forward and at the same time, the plunger 6 is pushed. Subsequently, the second valve seat portion 6c of the plunger 6 is separated from the distal end of the poppet valve 5 so that the transformer chamber 1e and the inside of the valve body 2 communicate with each other through the transformer passage 2f. The poppet valve 5 made of an elastic material is seated on the first valve seat portion 2d so that communication between the positive pressure chamber 1f and the transformer chamber 1e is interrupted.

Accordingly, the external air introduced into the valve body 2 through the air suction unit 2a flows into the transformer chamber 1e through the transformer passage 2f. At this time, the external air is instantaneously introduced by the differential pressure, and the operable diaphragm 1c and the power piston 1d are pushed toward the positive pressure chamber 1f, and the output amplified than the input through the reaction disk 4a is It is transmitted to the master cylinder assembly A through the output shaft 4 to generate braking hydraulic pressure. And the hydraulic pressure is delivered to the wheel cylinder (not shown) to the braking action, this operation occurs almost instantaneously.

When the foot is released from the brake pedal (not shown), the plunger 6 and the input shaft 3 are restored by the elastic restoring force of the restoring spring 1h and the power piston 1d and the spring 3b. Accordingly, the tip of the poppet valve 5 is seated on the second valve seat portion 6c of the plunger 6 and separated from the first valve seat portion 2d, whereby the transformer passage 2f is closed and the positive pressure passage 2e is provided. Is instantaneously communicating. In addition, the air in the transformer chamber 1e exits the positive pressure chamber 1f in a vacuum state through the positive pressure passage 2e, and the constant pressure chamber 1f is vacuumed by a negative pressure source, and thus the initial stage of the brake booster. It is in a state.

In the operation of such a power boosting device, since atmospheric air flows into the transformer chamber 1e in a vacuum state at a considerable speed due to the pressure difference, suction noise is transmitted to the outside of the valve body 2 to prevent this. The silencer 2b is provided in the air suction part 2a.

The structure thereof is described in more detail with reference to FIG. 2 as follows. When the driver steps on the brake pedal (not shown), as shown in the figure, the input shaft 3 moves forward to be seated on the second valve seat portion 6c of the plunger 6 to serve as an air valve. ) Is separated and seated on the first valve seat portion 2d.

Therefore, atmospheric pressure air flows into the vacuum transformer chamber 1e through the gap formed between the second valve seat portion 6c and the poppet valve 5, and the power piston 1d has a considerable force due to the differential pressure. Advance to and gain strength.

At this time, the flow path of the sucked air passes through the gap between the second valve seat portion 6c and the tip end of the poppet valve 5 at a right angle at the outer circumferential surface of the rear end 6b of the plunger 6 to guide the transformer passage 2f. As a result, vortices are generated at the outer peripheral surface portion of the rear end 6b of the plunger 6. This results in a significant inflow resistance, which also doubles the suction noise.

Conventionally, in order to reduce the noise, the silencer 2b is installed in the air suction part 2a of the valve body 2, but there is a limit in reducing the noise generated due to the air inflow resistance. Therefore, the suction noise is transmitted to the outside, and the driver is uncomfortable, and the driving safety is disturbed.

The present invention is to solve this problem, the object of the present invention is to selectively seat the front end of the poppet valve to perform the air valve function, the outer peripheral surface of the rear end of the plunger provided with the second valve seat portion at the end and inflow direction of air By constructing the same inclined surface, it is to provide a power boosting device for a vehicle brake that the external air is smoothly guided to the transformer chamber through the rear end inclined surface of the plunger during the braking action.

1 is a cross-sectional view schematically showing a power boosting device of a conventional vehicle brake.

Figure 2 is an enlarged view of the main part showing the operating state of the valve body.

3 is a cross-sectional view showing the overall structure of the brake power boosting device for a vehicle according to the present invention.

Figure 4 is a cross-sectional view of the main portion taken to extract the operating state of the valve body according to the present invention.

* Description of the symbols for the main parts of the drawings *

10. Casing 15. Transformer chamber 16. Constant pressure chamber

26. Transformer passage 60. Plunger 62. Rear end

63. Second valve seat 65. Slope

The present invention for achieving this purpose, the casing consisting of the front cell and the rear cell, the diaphragm and power piston, which divides the inside of the casing into the constant pressure chamber and the transformer chamber, one end is fixed to the center of the diaphragm and the power piston and the other end thereof Has a valve body with air suction, a poppet valve installed in the valve body to selectively communicate with and shut off the transformer chamber and the outside air, an input shaft having one end built into the valve body to operate the poppet valve, and a tip end of the poppet valve selectively seated In the boosting device for a vehicle brake having a plunger formed to separate the poppet valve so as to control the air inflow into the seal and the external air flows when the input shaft advances,

The outer circumferential surface of the rear end of the plunger having the valve seat portion formed at the end is characterized by consisting of a slope in which the outer diameter gradually expands in the air inflow direction to guide the air inflow.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a cross-sectional view showing the overall structure of the brake booster according to the present invention, Figure 4 is an enlarged cross-sectional view of the main portion showing the internal structure of the valve body with a built-in plunger according to the present invention.

As shown in these, in the vehicle brake power boosting device according to the present invention, the interior of the casing 10 in which the front cell 11 and the rear cell 12 are hermetically coupled to the power piston 14 and the diaphragm 13. It is divided into a constant pressure chamber 16 and a transformer chamber 15, the input shaft for operating the valve body 20, the valve body 20 for controlling the air flow path to the transformer chamber 15 and the constant pressure chamber 16 ( 30) and the output shaft 40 is largely configured to receive the doubled force. One outer wall of the front cell 11 is provided with a negative pressure inlet pipe 17 such as an intake manifold (MANIFOLD) for communicating the positive pressure chamber 16 with the negative pressure source, and a restoring spring 18 is provided inside the positive pressure chamber 16. It is installed. The valve body 20 is provided with a constant pressure passage 25 for communicating the constant pressure chamber 16 and the transformer chamber 15 and a transformer passage 26 for communicating the outside air and the transformer chamber 15.

The valve body 20 for controlling the inflow of air into the transformer chamber 15 is provided in the center of the rear cell 12, one end of which is fixed to the diaphragm 13 and the power piston 14, the other end of the rear cell. Protruding outward from the center of (12) to form an air intake portion 21 provided with a silencer 22 and a filter 23. The valve body 20 has a cylindrical structure, and a cylinder portion 27 is formed in the axial direction at an inner end thereof, and a plunger 60 for sliding the cylinder portion 27 is provided.

A rear end portion 62 of the plunger 60 is formed in a recess recess 64 recessed to a predetermined depth, and an end portion of the input shaft 30 coupled with a brake pedal (not shown) is fitted and coupled to the front end portion 61 thereof. The output shaft 40 is installed, the reaction disk 41 is provided between the output shaft 40 and the distal end portion 61 of the plunger 60 to double the force applied due to the difference in the cross-sectional area to transmit to the output shaft 40. have. Inside the valve body 20, a poppet valve 50 of elastic material having flowability is firmly installed. The tip of the poppet valve 50 is selectively seated on the inner circumferential surface of the valve body 20 by the operation of the input shaft 30 to close the constant pressure passage 25, that is, the first valve seat 24 having a valve function. Is provided, the poppet valve 50 and the first valve seat portion 24 is combined to form a vacuum valve. That is, when the front end portion of the poppet valve 50 is seated on the first valve seat 24, the positive pressure passage 25 is closed, whereby communication between the positive pressure chamber 16 and the transformer chamber 15 is blocked. In addition, the front end of the poppet valve 50 is selectively seated at the end of the rear end 62 of the plunger 60 coupled to the end of the input shaft 30 by the operation of the input shaft 30 so that the air of the outside air is transformed into a transformer chamber ( A second valve seat portion 63 is formed to block the inflow to 15, that is, a valve function, and the poppet valve 50 and the second valve seat portion 63 are combined to form an air valve.

The outer circumferential surface of the rear end portion 62 of the plunger 60 having the second valve seat portion 63 formed at an end thereof is a characteristic element of the present invention and is formed of an inclined surface 65 to be the same as the inflow direction of air. That is, the rear end 62 of the plunger 60 has a truncated conical shape, and the outer diameter of the rear end 62 is gradually expanded to be formed in the inclined surface 65 to be the same as the air inflow direction, thereby greatly reducing the air inflow resistance. do. Accordingly, when the front end portion of the poppet valve 50 is seated on the second valve seat portion 63, the air of the outside air cannot be introduced by the air valve, but when dropped, the air flows through the gap between them and continues to be plunger 60. Since it is smoothly guided to the transformer passage 26 while hitting the inclined surface 65 of the rear end 62, the suction noise is reduced. This is described again in detail in the operation description below.

Next will be described the operation of the power boosting device for a vehicle brake according to the present invention configured as described above.

When the driver presses a brake pedal (not shown) in the vehicle equipped with the power supply apparatus according to the present invention and the input shaft 30 coupled to the valve body 20 is advanced, the plunger 60 is pushed down and at the same time, the poppet valve The tip end portion 50 is separated from the second valve seat portion 63 formed on the plunger 60 and seated on the first valve seat portion 24.

Accordingly, the communication between the constant pressure chamber 16 and the transformer chamber 15 is interrupted, and the air of the outside air is caused by the gap between the poppet valve 50 and the second valve seat portion 63. 21 flows into the transformer chamber 15 in a vacuum state through the transformer passage 26. Therefore, due to the differential pressure, the outside air is momentarily introduced into the transformer chamber 15 so that the diaphragm 13 and the power piston 14 which can be operated are pushed toward the positive pressure chamber 16 side, and are installed at the center of the power piston 14. An output amplified than the input through the reaction disk 41 is transmitted to the master cylinder assembly A through the output shaft 40 to generate pressure. This pressure is transferred to a wheel cylinder (not shown) to cause braking, which occurs almost instantaneously.

When the foot is released from the brake pedal (not shown), the plunger 60 and the input shaft 30 are restored again by the restoring spring 18, and at the same time, the second valve seat formed at the rear end 62 of the plunger 60. The part 63 pushes the poppet valve 50 to separate from the first valve seat 24 and serves as an air valve to prevent the inflow of air. In addition, as the poppet valve 50 is separated from the first valve seat 24, the positive pressure passage 25 communicates with each other, so that the air in the transformer chamber 15 is discharged into the positive pressure chamber 16 in a vacuum state. 16 is a vacuum state by a negative pressure source (not shown), and becomes the initial state of the brake booster.

On the other hand, the air sucked at a considerable speed through the gap between the second valve seat portion 63 and the poppet valve 50 in the operation of the power supply device is a plunger 60 consisting of the inclined surface 65 as shown in FIG. A) hitting the outer circumferential surface 65 of the rear end 62 and guided to the transformer passage 26 and continuously introduced into the transformer chamber 15, the rear end 62 of the plunger 60 as a characteristic action of the present invention. The outer circumferential surface is composed of the same inclined surface 65 as the inflow direction of the air is made smoothly inlet air. Therefore, the generation of vortex during the air inlet is reduced, the inlet resistance is minimized, the overall operating noise is reduced.

As described above in detail, the power boosting device for a brake for a vehicle according to the present invention includes a rear end surface of a plunger having a second valve seat portion at an end thereof to selectively seat the front end portion of the poppet valve to perform an air valve function, and inflow direction of air In the same manner as the slope.

Therefore, the external air is smoothly guided to the transformer chamber through the inclined surface of the rear end of the plunger during the braking action, thereby reducing the intake noise due to the reduction of the inflow resistance.

Claims (1)

A casing 10 composed of a front cell 11 and a rear cell 12, a diaphragm 13 and a power piston 14 that divide the casing 10 into a constant pressure chamber 16 and a transformer chamber 15. One end portion is fixed to the center of the diaphragm 13 and the power piston 14, and the other end thereof is installed in the valve body 20, the valve body 20 is formed with an air suction portion 21 Poppet valve 50 for selectively communicating with and blocking the transformer chamber 15 from outside air, one end of which is installed in the valve body 20 to operate the poppet valve 50, and the poppet valve ( The valve seat portion 63 is separated from the poppet valve 50 so as to selectively seat the front end portion 50 to control the air inflow into the transformer chamber 15 and to allow external air to flow in when the input shaft 30 is advanced. In the booster for a vehicle brake having a plunger 60 formed, The outer circumferential surface of the rear end portion 62 of the plunger 60 having the valve seat portion 63 formed at the end is formed of an inclined surface 65 whose outer diameter is gradually expanded in the air inflow direction to guide the air inflow. Brake booster.