KR101197474B1 - Brake booster - Google Patents

Abstract

The present invention is to provide a brake booster, the cell having a constant pressure chamber and the transformer chamber, the pressure chamber and the transformer chamber in communication with the operation of the input shaft or the transformer chamber is in communication with the atmosphere and the pressure difference between the pressure chamber and the transformer chamber And a valve device for pressurizing the output shaft while moving by the valve device, wherein the valve device includes a valve body having a first flow path for communicating the constant pressure chamber and the transformer chamber and a second flow path for communication between the transformer chamber and the atmosphere, and for advancing with the input shaft. A plunger installed in the valve body and having an opening and closing portion for selectively opening and closing the first and second flow paths, an elastic reaction disk interposed between the valve body and the output shaft, and coupled to the plunger tip to pressurize the reaction disk. Pressurized piston capable of advancing and retracting in direction of pressure, and transfer pressure of valve body to reaction disk To support can advance and retreat and a latch that restrict the pressure piston when the support cylinder is installed in the valve body, the emergency braking movement within the support cylinder.

Description

Brake booster {BRAKE BOOSTER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake power boosting device, and more particularly, to a brake power boosting device which raises the output rapidly when emergency braking is performed and at the same time, it is suitable for exerting a large output even when the pressure of the brake pedal is weak.

In general, the brake power booster is a device that can exhibit a large braking force even with a small force by using the pressure difference between the intake pressure and the atmospheric pressure of the vehicle engine. In other words, when the driver presses the brake pedal, the device generates much more power than the force applied to the pedal.

1 is a cross-sectional view showing a conventional brake booster. As shown, the power supply apparatus includes a cell 1 having a positive pressure chamber 2 and a transformer chamber 3 partitioned therein. In addition, according to the operation of the input shaft 4, the positive pressure chamber 2 and the transformer chamber 3 communicate with each other so that the pressures in the positive pressure chamber 2 and the transformer chamber 3 are equal to each other, or the constant pressure chamber 2 and the transformer chamber ( The valve device 5 is provided so that communication of 3) is interrupted and the transformer chamber 3 is in communication with the atmosphere so that a pressure difference is generated between the constant pressure chamber 2 and the transformer chamber 3. The suction pressure of the vehicle engine acts on the positive pressure chamber 2.

This power supply device is the positive pressure chamber (2) and the transformer chamber (3) is blocked when the input shaft (4) is advanced by the pressure of the brake pedal (not shown) and the transformer chamber (3) is in communication with the atmosphere ) And the pressure difference chamber 3 occurs. This pressure difference moves the power piston 6 and the valve device which partitions the constant pressure chamber 2 and the transformer chamber 3 toward the output shaft 7 to press the output shaft 7 so that an output amplified than the input is produced. . In addition, when such an operation is performed, the pressure in the transformer chamber gradually rises to the atmospheric pressure when the transformer chamber 3 and the atmosphere communicate with each other while the entry of the input shaft 4 is continuously maintained.

The above-described brake booster is difficult to raise the pressure in the transformer chamber quickly because the driver cannot step on the brake pedal sufficiently to avoid slippage of the vehicle in an emergency braking situation. There was a problem that was difficult to ascend. Especially for the elderly, it was difficult to perform emergency braking because the force to press the input shaft through the brake pedal is weak and it is difficult to continuously pressurize the input shaft.

Accordingly, the present invention is to solve such a problem, it is an object of the present invention to provide a brake power boosting device that can quickly increase the output of the power booster when performing emergency braking.

Another object of the present invention is to provide a brake power boosting device that can exert sufficient output even when the force for pressing the input shaft is weak when performing emergency braking.

In order to achieve the above object, the brake power booster according to the present invention, the positive pressure chamber and the transformer chamber, and the constant pressure chamber and the transformer chamber in communication with the operation of the input shaft or the transformer chamber is in communication with the atmosphere And a valve device configured to pressurize the output shaft while moving by the pressure difference between the constant pressure chamber and the transformer chamber, wherein the valve device includes a first flow path for communication between the constant pressure chamber and the transformer chamber and a second path for communication between the transformer chamber and the atmosphere. A plunger having a valve body having a flow path, a plunger installed in the valve body to retreat with the input shaft and selectively opening and closing the first and second flow paths, and an elastic material interposed between the valve body and the output shaft. A reaction disc of the plunger and coupled to the plunger tip to pressurize the reaction disc. A pressurized piston capable of moving back and forth, a support cylinder installed in the valve body to transfer the pressing force of the valve body to the reaction disk and to support the pressurized piston in a retractable manner, and the pressurized piston moves in the support cylinder. It characterized in that it comprises a latch for limiting.

The latch of the brake power booster according to the present invention is provided so as to be able to move forward and backward in the radial direction of the support cylinder by an annular spring to restrain the pressure piston by being caught by a locking step provided on the outer circumferential surface of the pressure piston.

The brake further includes a sleeve that is removably installed between the support cylinder and the pressure piston of the brake power supply device, wherein the latch is separated from the locking jaw by the sleeve to release the restraint of the pressure piston Gong.

The brake booster according to the present invention further comprises a disk installed on the reaction disk to transmit the pressing force of the pressure piston to the center of the reaction disk.

The brake booster according to the present invention further comprises a return spring provided between the pressing piston and the disk to impart elasticity to move the pressing piston toward the plunger.

As described above, in the brake power booster according to the present invention, since the pressure piston is spaced from the plunger as the pressure piston is restrained from the plunger during emergency braking by the operation of the latch, the reaction force is not applied to the input shaft so that the force to press the input shaft is weak. In this case, there is an effect that the output of the power booster can be quickly increased, and at the same time, sufficient output can be obtained.

Hereinafter, with reference to the accompanying drawings a preferred embodiment according to the technical spirit of the brake power booster of the present invention as described above is as follows.

As shown in FIG. 2, the brake booster according to the present invention divides the sealed cell 10 and the inner space of the cell 10 into a front positive pressure chamber 11 and a rear transformer chamber 12 at a rear side thereof. The power piston 13 and the diaphragm 14 provided in the inside of 10 are provided. The pipe 15 provided on the front of the cell 10 is connected to an external negative pressure source (such as an intake manifold of the vehicle). Therefore, the constant pressure chamber 11 is maintained at low pressure.

An opening 16 is provided in the rear center of the cell 10, and the opening 16 is provided with a positive pressure chamber 11 and a transformer chamber according to an operation of an input shaft 17 connected to a brake pedal (not shown) of a vehicle driver's seat. The pressure between the positive pressure chamber 11 and the transformer chamber 12 is caused by the communication between the positive pressure chamber 11 and the transformer chamber 12 and the transformer chamber 12 in communication with the atmosphere. The valve device 20 which makes a difference arise is provided.

2 and 3, the valve device 20 is installed inside the hollow valve body 21 and the valve body 21, the plunger (opening and closing the flow path in accordance with the operation of the input shaft 17 ( 22) and poppet valves (23).

The valve body 21 is supported by the opening 16 at the rear of the cell 10 so as to be retractable, and the power piston 13 and the diaphragm 14 are fixed to the outer surface of the tip portion entering the cell 10. Therefore, the valve body 21 moves forward and backward with the power piston 13 when the power piston 13 moves forward due to the pressure difference between the positive pressure chamber 11 and the transformer chamber 12.

In front of the valve body 21 inside the cell 10 is provided an output shaft 18 which penetrates the center of the cell 10 and is connected to a master cylinder (not shown), and the rear end of the output shaft 18 is elastically deformed. Possible reaction disk 25 is coupled to the valve body 21 via. For this coupling, a cup-shaped coupling portion 24 is provided at the rear end of the output shaft 18, and the reaction disk 25 is accommodated in the cup-shaped coupling portion 24. In addition, a restoring spring 19 for providing restoring force to the valve body 21 is provided outside the output shaft 18.

The valve body 21 includes a first flow path for communicating the constant pressure chamber 11 and the transformer chamber 12 and a second flow path for communicating the transformer chamber 12 with the atmosphere. The first flow path is formed in the longitudinal direction on the outer side of the hollow portion 26 so as to communicate with the positive pressure chamber 11, and in the radial direction of the hollow portion 26 to communicate with the transformer chamber 12. The formed second communication path 28 is a flow path that is formed when communicating with each other through the hollow portion 26, the second flow path air inlet in the rear end of the valve body 21 in the state in which the first communication path 27 is blocked It is a flow path formed when the 29 and the second communication path 28 communicate with each other through the hollow portion 26.

The poppet valve 23 and the plunger 22 installed in the hollow portion 26 of the valve body 21 selectively open these first flow passages and the second flow passages as the input shaft 17 moves forward and backward. The plunger 22 is coupled to the front end of the input shaft 17 and retracts with the input shaft 17, and has an opening and closing portion 30 for opening and closing the flow path while being in contact with or spaced apart from the front end of the poppet valve 23. The poppet valve 23 is fixed to the inner surface of the valve body 21 outside the input shaft 17 and is provided in the form of a corrugated pipe that can be expanded and contracted.

The valve device 20 has a positive pressure chamber (2) by opening the first communication path 27 while the poppet valve 23 is pushed backward by the opening and closing portion 30 at the rear end of the plunger 22 when the input shaft 17 is retracted. 11) and the transformer chamber 12 is in communication with each other and the introduction of the outside air is blocked by the contact between the opening and closing portion 30 and the tip of the poppet valve (23). Therefore, at this time, both the positive pressure chamber 11 and the transformer chamber 12 are in a negative pressure state, so that the valve body 21 is pushed backward by the elasticity of the restoring spring 19.

When the input shaft 17 moves forward, the contact between the poppet valve 23 and the plunger 22 opening and closing portion 30 is released, and the poppet valve 23 extends forward to close the first communication path 27. The air inlet 29 at the rear end of the valve body 21 communicates with the second communication path 28 by the gap between the opening and closing portion 30 and the poppet valve 23. Therefore, at this time, since the positive pressure chamber 11 is maintained at the negative pressure state and the atmosphere flows into the transformer chamber 12, the power piston 13 inside the cell 10 is caused by the pressure difference between the positive pressure chamber 11 and the transformer chamber 12. It is pushed toward this constant pressure chamber 11. When the power piston 13 is pushed toward the positive pressure chamber 11, the valve body 21 also moves forward so that the valve body 21 pushes the output shaft 18 with great force.

As shown in FIG. 2, the support pin 31 is fitted into the second communication path 28 of the valve body 21. The support pin 31 prevents the inner end of the plunger 22 and the input shaft 17 from being coupled to the inside of the valve body 21 by being caught by the locking groove 32 of the plunger 22, and the outer end of the support pin 31. It catches on the inner surface of the cell 10 to limit the retraction of the valve body 21.

In the valve body 21, a support cylinder 50 fixed to the valve body 21 is provided in a state where the front end is in contact with the rear circumference of the reaction disk 25 and the rear end is in contact with the valve body 21. Therefore, the support cylinder 50 transmits the pressing force when the valve body 21 advances to the reaction disk 25. In addition, a disk 60 is provided at the center of the reaction disk 25 so as to transmit the pressing force of the plunger 22 to the center of the reaction disk 25. That is, the disk 60 is provided at the center of the support cylinder 50 to be in contact with the reaction disk 25. In addition, the disk 60 is opposed to the pressing piston 51 to be described later coupled to the tip of the plunger 22 to receive the pressing force of the plunger 22.

The valve body 21 is provided with a pressing piston 51 coupled to the tip of the plunger 22 to pressurize the reaction disk 25. The pressing piston 51 is formed in a cylindrical shape stepped a plurality of times in the longitudinal direction. More specifically, a cylindrical portion 52 protruding rearward is provided at the center of the rear end of the pressing piston 51, and the locking jaw 56 is provided at the body between the front end and the rear end of the pressing piston 51. That is, the locking jaw 56 is smaller than the diameter of the front end portion of the pressing piston 51, and is formed larger than the diameter of the cylindrical portion 52 of the rear end. The cylindrical portion 52 of the pressure piston 51 is coupled to the inner surface of the tip side of the plunger 22 to be retractable. In addition, a return spring 53 is provided between the distal end of the pressing piston 51 and the disk 60 to provide elasticity to the pressing piston 51 toward the plunger 22 side.

In addition, a rear end of the support cylinder 50 is provided with a latch 54 for restraining the pressure piston 51 during emergency braking. More specifically, the latch 54 is disposed to surround the outer circumferential surface of the tip portion of the pressing piston 51, and an annular spring 55 is provided on the outer circumferential surface of the latch 54. Accordingly, the latch 54 is made to be able to advance and retract in the radial direction of the support cylinder 50 by the spring 55. In addition, the latch 54 is formed such that the portion in contact with the pressure piston 51 is stepped so that the latch 54 is caught by the locking jaw 56 provided on the outer circumferential surface of the pressure piston 51 in case of emergency braking. To limit movement. That is, when the pressing piston 51 moves forward and the latch 54 is located at the portion where the locking jaw 56 is provided, the latch 54 contacts the locking jaw 56 by the elastic force of the spring 55. By moving toward the center so as to limit the movement of the pressing piston (51).

In order to release the pressing piston 51 constrained by the latch 54, a cylindrical sleeve 57 is provided between the pressing piston 51 and the support cylinder 50 in a retractable manner. More specifically, the sleeve 57 is installed to surround the outer circumferential surface of the pressure piston 51 and is disposed to face the latch 54. At this time, the sleeve 57 has an extension portion 57a extending forward, and the extension portion 57a has the same thickness as that of the locking step 56. That is, the diameter of the extension portion 57a has a diameter corresponding to the outer diameter at the tip side of the pressure piston 51. The extension part 57a is for releasing the latch 54 that restricts the movement of the pressure piston 51 from the locking step 56. An extension 57a having a thickness corresponding to the locking step 56 is provided. The restraint of the pressure piston 51 is released by pushing the latch 54 while moving toward the locking jaw 56.
On the other hand, the outer surface of the extension portion (57a) is provided with a support member (58a) provided in contact with the latch 54, the support spring 58 is disposed between the support member (58a) and the sleeve (57) by the sleeve 57 ) Is applied to the plunger 22 side.

The following describes the operation of the brake booster according to the present invention.

When the normal braking operation (not emergency braking) is performed, the plunger 22 moves forward with the entry of the input shaft 17, and the pressure piston 51 moves forward by the plunger 22, so that the opening / closing portion 30 of the plunger 22 is moved. ) Is spaced apart from the poppet valve 23 and the poppet valve 23 blocks the first communication path 27. In this case, as shown in FIG. 4, the latch 54 moves on the outer circumferential surface of the pressure piston 51 while the plunger 22 advances the pressure piston 51. That is, the latch 54 is provided in the state which presses the outer peripheral surface of the front end side of the pressing piston 51. As shown in FIG.

Therefore, at this time, communication between the constant pressure chamber 11 and the transformer chamber 12 is blocked, and the transformer chamber 12 and the air communicate with each other, so that the pressure of the transformer chamber 12 increases. When the power piston 13 is advanced by the pressure difference between the constant pressure chamber 11 and the transformer chamber 12 according to the pressure rise of the transformer chamber 12, the valve body 21 is also advanced and presses the output shaft 18. . At this time, since the valve body 21 moves forward, the poppet valve 23 and the opening / closing portion 30 of the plunger may contact each other, but since the pressurization of the plunger 22 by the input shaft 17 is maintained, this operation is repeated. Leads to. Therefore, the braking operation is performed while the pressure in the transformer chamber 12 gradually rises. In this case, when the pedal is continuously pressed, when the input shaft 17 moves forward, as shown in FIG. 5, when the pressure piston 51 moves forward, the portion where the locking jaw 56 is formed faces the latch 54. , The latch 54 is caught by the locking jaw 56 by the elastic force of the spring 55 to restrain the pressing piston 51.

On the other hand, when performing the emergency braking, as shown in Figure 6, in addition to the braking operation as described above, the plunger 22 advances rapidly and enters more deeply at the beginning of the braking operation so that the locking step 56 of the pressure piston 51 ) Is latched by the latch 54. That is, as the input shaft 17 moves forward, the contact between the poppet valve 23 and the plunger 22 opening / closing part 30 is released, and the air flows into the transformer chamber 12 so that the positive pressure chamber 11 and the transformer chamber 12 are released. The valve body 21 is advanced by the pressure difference of the pressure piston 51. At this time, since the pressure piston 51 is restrained by the latch 54, the pressure piston 51 moves away from the plunger 22 and moves forward together with the valve body 21. Done. Therefore, as the force transmission shaft connected from the input shaft 17 to the output shaft 18 is separated from the pressure piston 51 and the plunger 22, the reaction force is applied to the valve body through the pressure piston 51 and the latch 54. Since it is bypassed to 21, it is not transmitted directly to the input shaft 17. Accordingly, even when the pressing force of the input shaft 17 is weak, the separation between the opening and closing portion 30 of the plunger 22 and the poppet valve 23 is maintained, so that the air flows smoothly into the transformer chamber 12 so that the transformer chamber 12 Pressure rises quickly.

When the braking is released, the opening / closing portion 30 of the plunger 22 first contacts the poppet valve 23 and pushes the poppet valve 23 backward, thereby blocking the inflow of air and simultaneously opening the first communication path 27. The positive pressure chamber 11 and the transformer chamber 12 communicate with each other. Therefore, since both the positive pressure chamber 11 and the transformer chamber 12 are in a negative pressure state, the valve body 21 is pushed backward by the elasticity of the restoring spring 19. In this case, if the valve body 21 is pushed backward until the support pin 31 is caught, the extension 57a of the sleeve 57 is in contact with the locking jaw 56 as shown in FIG. The latch 54 is pushed up so that the restraint of the pressure piston 51 is released. The pressing piston 51 is returned to the initial position by the return spring 53.

1 is a cross-sectional view of a conventional brake booster.

2 is a cross-sectional view of the brake booster according to the present invention.

3 is a cross-sectional view showing a valve device of the brake booster according to the present invention.

Figure 4 is a cross-sectional view showing a valve device of the brake booster according to the present invention, showing a state in which a normal braking operation is performed.

Figure 5 is a cross-sectional view showing a valve device of the brake booster according to the present invention, showing a state in which the latch is operated during a normal braking operation.

Figure 6 is a cross-sectional view showing a valve device of the brake booster according to the present invention, showing a state in which emergency braking is made.

7 is a cross-sectional view showing a valve device of the brake booster according to the present invention, showing a state in which the brake is released.

Explanation of symbols on the main parts of the drawings

10: cell 11: constant pressure chamber

12: transformer chamber 13: power piston

14: diaphragm 17: input shaft

18: output shaft 19: restoring spring

20: valve device 21: valve body

22: Plunger 23: Poppet Valve

25: Reaction disc 27: First communication path

28: second communication path 30: opening and closing portion

31: support pin 50: support cylinder

51: pressure piston 53: return spring

54: latch 55: spring

56: engaging jaw 57: sleeve

58: support spring 60: disc

Claims (5)

A cell having a constant pressure chamber and a transformer chamber, and a valve for allowing the constant pressure chamber and the transformer chamber to communicate with each other according to the operation of the input shaft or the transformer chamber to communicate with the atmosphere, and pressurizing the output shaft while moving by the pressure difference between the constant pressure chamber and the transformer chamber. Including a device, The valve device has a valve body having a first flow path for communication between the constant pressure chamber and the transformer chamber and a second flow path for communication with the transformer chamber and the atmosphere, and installed in the valve body so as to retreat with the input shaft. And a plunger having an opening and closing portion for selectively opening and closing a second flow path, an elastic reaction disc interposed between the valve body and the output shaft, coupled to the plunger tip to pressurize the reaction disc, and the retraction of the plunger. A pressure piston capable of moving forward and backward, a support cylinder installed in the valve body to transfer the pressing force of the valve body to the reaction disk and to support the pressure piston in a retractable manner, and the pressure piston being supported during emergency braking. A latch to restrict movement within the cylinder, The latch is provided to the rear of the support cylinder to surround the outer peripheral surface of the tip end side of the pressing piston, an annular spring is installed on the outer peripheral surface of the latch to enable the retracting in the radial direction of the supporting cylinder is provided on the outer peripheral surface of the pressing piston When the latching jaw is moved to a position corresponding to the latch, the latch is locked to the latching jaw to restrain the pressure piston, It is provided on the outer circumferential surface of the pressing piston so as to face the latch is provided to be capable of moving in the longitudinal direction of the pressing piston, and further comprising a sleeve having an extension protruding toward the latch to have the same thickness as the locking jaw, The latch is a brake booster, characterized in that the extension portion is moved away from the locking jaw when in contact with the locking jaw to release the constraint of the pressure piston. delete delete The method of claim 1, And a disk installed in the reaction disk to transfer the pressing force of the pressure piston to the center of the reaction disk. 5. The method of claim 4, And a return spring provided between the pressure piston and the disk to impart elasticity to move the pressure piston toward the plunger.

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