KR20100098831A - Brake booster - Google Patents

Abstract

PURPOSE: A brake booster is provided to rapidly raise the output in case of sudden brake and to produce sufficient output even if the power applied to an input shaft is weak. CONSTITUTION: A brake booster comprises a shell(10) and a valve device(20). The shell comprises a constant pressure chamber(11) and a variable pressure chamber(12). According to the operation of the input shaft, the valve device connects the constant pressure chamber to the variable pressure chamber. The valve device pressurizes the output shaft while moving by the pressure difference of the constant pressure chamber and the variable pressure chamber. The valve device comprises a valve body(21), a plunger(22) and a reaction disc(25). The valve body comprises a first flow path and a second flow path which connects the variable pressure chamber to atmosphere. The plunger is installed in the valve body in order to move back and forth with the input shaft. The reaction disc is interposed between the valve body and the output shaft.

Description

Brake booster {BRAKE BOOSTER}

The present invention relates to a brake power booster, and more particularly, to a brake power booster that is capable of rapidly increasing output when emergency braking is performed, and at the same time, exhibiting 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 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 5 which divides the constant pressure chamber 2 and the transformer chamber 3 toward the output shaft 7 and presses the output shaft 7 to generate an amplified output than the input. To do that. 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.

According to an exemplary embodiment of the present invention, a brake power supply apparatus includes a cell having a positive pressure chamber and a transformer chamber; and the constant pressure chamber and the transformer chamber are in communication with each other or the transformer chamber is in communication with the atmosphere according to the operation of an input shaft. And a valve device configured to pressurize the output shaft while moving by the valve device, wherein the valve device comprises 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 between the transformer chamber and the atmosphere; A plunger installed in the valve body to retract with the input shaft and having an opening and closing portion for selectively opening and closing the first and second flow paths, an elastic reaction disc interposed between the valve body and the output shaft, and the valve body And a support cylinder disposed between the reaction disk and a protrusion projecting inward to form a locking step. And a pressurizing disk accommodated in the support cylinder and disposed between the reaction disk and the plunger, one end of which is fixed to the pressurizing disk and the other end of which is locked to the locking jaw of the support cylinder according to the position of the plunger. And a member.

The protruding portion includes a protruding surface extending along the axial direction of the support cylinder, and the locking member slides on the protruding surface during normal braking.

The locking member may include a leaf spring capable of elastic deformation in the radial direction of the support cylinder.

The protrusion of the support cylinder has a through hole formed in the axial direction of the support cylinder, and the plunger extends into the support cylinder through the through hole of the support cylinder when the support cylinder moves toward the plunger. It may include a sleeve for deforming the locking member.

A curved surface may be formed at the other end of the locking member, and an inclined surface may be formed at an end of the sleeve extending into the support cylinder to guide the sleeve to smoothly enter between the locking member and the support cylinder.

As described above, the brake power booster according to the present invention does not apply the reaction force of the reaction disk to the input shaft during emergency braking, so that the output of the power booster can be quickly increased and sufficient output can be achieved even when the force applied to the input shaft is weak. It can be effective.

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.

The valve device 20 further includes a support cylinder 40 disposed between the valve body 21 and the reaction disk 25. One side of the front end of the support cylinder 40 is in contact with the rear circumference of the reaction disk 25, and the other side of the front end of the support cylinder 40 is fixed to the valve body 21 in contact with the valve body 21. do. Therefore, the support cylinder 40 transmits the pressing force when the valve body 21 moves forward to the reaction disk 25.

The pressing disk 50 and the locking member 60 are accommodated in the support cylinder 40. The pressurizing disk 50 is installed to be movable in the axial direction (X direction). The pressurizing disk 50 is disposed between the reaction disk 25 and the plunger 22 and has a receiving groove 52 for receiving the tip of the plunger 22.

The rear end of the support cylinder 40 is provided with a protrusion 43 protruding from the inner surface 41 of the support cylinder 40 to form a locking jaw 42 in the support cylinder 40. The protrusion 43 has a protruding surface 44 extending in the axial direction by a predetermined length.

The locking member 60 restrains the pressure disk 50 to the support cylinder 40 during emergency braking so that the pressure disk 50 moves together with the valve body 21. One end of the locking member 60 is fixed to the rear end of the pressurizing disk 50 and the other end extends toward the inner side 41 of the support cylinder 40.

The locking member 60 slides on the protruding surface 44 of the protruding portion 43 during normal braking. However, in the case of emergency braking, the locking member 60 is caught by the locking jaw 42 of the support cylinder 40 to support the pressure disk 50. Binding to 40.

The locking member 60 may be provided as a leaf spring installed to enable elastic deformation in the radial direction of the support cylinder 40.

A through hole 44a is formed in the protrusion 43 of the support cylinder 40 in the axial direction, and the through hole of the support cylinder 40 when the support cylinder 40 moves toward the plunger 22 is formed in the plunger 22. A sleeve 22a may be provided to extend into the support cylinder 40 through 44a to deform the locking member.

As the sleeve 22a enters between the inner surface 41 of the support cylinder 40 and the locking member 60, the locking member 60 is elastically deformed and spaced apart from the inner surface 41 of the support cylinder 40, Accordingly, the locking member 60 may be separated from the locking jaw 42 and returned to the protruding surface 44 of the protrusion 43.

A curved surface 61 is formed at the end of the locking member 60 so that the sleeve 22a can smoothly enter between the locking member 60 and the support cylinder 40, and an inclined surface 22b at the end of the sleeve 22a. This can be formed.

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

When a normal braking operation (not emergency braking) is performed, the plunger 22 advances as the input shaft 17 enters. In this case, as shown in FIG. 4, the plunger 22 advances the pressurizing disk 50, and the locking member 60 connected to the pressurizing disk 50 is connected to the protrusion 43 of the support cylinder 40. It slides on the protruding surface 44.

When the plunger 22 is advanced, the opening and closing portion 30 of the plunger 22 is spaced apart from the poppet valve 23 and the poppet valve 23 blocks the first communication path 27. Therefore, communication between the constant pressure chamber 11 and the transformer chamber 12 is blocked, and the transformer chamber 12 and the atmosphere communicate with each other, so that the pressure of the transformer chamber 12 is increased. 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. However, 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.

When braking is performed in this way, emergency braking is required, and when the driver presses the input shaft 17 with a greater force, as shown in FIG. 5, the plunger 22 and the pressurizing disk 50 move forward, and the locking member ( 60 is placed in a position that can be caught on the locking projections 42 from the protruding surface 44 of the support cylinder (40). In this state, even when the plunger 22 is retracted, the pressing disk 50 is locked to the support cylinder 40, so that braking operation can be performed smoothly even with a small force during continuous braking.

On the other hand, when performing urgent braking by rapidly pressurizing the input shaft 17, the plunger 22 is advanced more deeply in the initial braking operation, so as shown in FIG. 6, the locking member 60 fixed to the pressing disk 50 is supported by the cylinder The locking jaw 42 of the 40 is caught.

As the input shaft 17 moves forward, when the opening / closing portion 30 of the plunger 22 is spaced apart from the poppet valve 23, the atmosphere flows into the transformer chamber 12, whereby the pressure difference between the positive pressure chamber 11 and the transformer chamber 12 is reduced. The valve body 21 is advanced by this, at this time, since the pressure disk 50 is constrained to the support cylinder 40 by the locking member 60, the pressure disk 50 is separated from the plunger 22 and the valve body You will move forward with (21).

When the pressing disk 50 and the plunger 22 are separated in this way, the reaction force acting as the pressing disk 50 in the reaction disk 25 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. In this state, even when the plunger 22 retreats, the locked state of the pressure disk 50 is maintained, so that braking operation can be performed smoothly even with a small force during continuous braking.

When the brake is released, as shown in FIG. 7, the valve body 21 is pushed backward by the elasticity of the restoring spring 19 as the input shaft 17 and the plunger 22 retreat. In this case, when the valve body 21 is pushed backward until the support pin 31 is caught, the sleeve 22a enters between the inner surface 41 of the support cylinder 40 and the locking member 60. Then, the locking member 60 is elastically deformed and compressed by the sleeve 22a, and the locking member 60 is separated from the locking jaw 42 by an elastic force acting as the pressure disk 50 in the reaction disk 25. It is possible to return to the protruding surface 44 of the protruding portion 43 (to return to the initial position).

1 is a view showing a brake booster according to the prior art.

2 is a view showing the configuration of a brake booster according to the present invention.

3 is a view showing an extract of a part in FIG.

4 is a view showing a state in which a conventional braking operation is performed in the brake booster according to the present invention.

5 and 6 are views showing a state in which emergency braking is performed in the brake power booster according to the present invention.

Figure 7 is a view showing a state in which the brake release in the brake power booster according to the present invention.

Explanation of symbols on the main parts of the drawings

10 cell 11: static pressure chamber

12: transformer chamber 20: valve device

21: valve body 22: plunger

22a: sleeve 25: reaction disk

40: support cylinder 42: locking jaw

43: protrusion 44: protrusion surface

50: pressure disk 60: locking member

Claims (5)

A cell with a constant pressure chamber and a transformer chamber; and And a valve device configured to communicate the constant pressure chamber and the transformer chamber with the operation of an input shaft, or to allow the transformer chamber to communicate with the atmosphere, and pressurize the output shaft while moving by a pressure difference between the constant pressure chamber and the transformer chamber. 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, and disposed between the valve body and the reaction disk to form a locking step. A support cylinder having a protrusion projecting toward the support cylinder, a pressurizing disk accommodated in the support cylinder and disposed between the reaction disk and the plunger, one end of which is fixed to the pressurizing disk and the other end of the pressurizing disk Brake boat characterized in that it comprises a locking member that is restrained on the locking jaw of the support cylinder Device. The method of claim 1, The protrusion includes a protruding surface extending along the axial direction of the support cylinder, And the locking member slides on the protruding surface during normal braking. The method of claim 1, The locking member is a brake booster, characterized in that it comprises a leaf spring capable of elastic deformation in the radial direction of the support cylinder. The method according to any one of claims 1 to 3, The protrusion of the support cylinder has a through hole formed in the axial direction of the support cylinder, And the plunger includes a sleeve extending through the through hole of the support cylinder to the inside of the support cylinder to deform the locking member when the support cylinder moves toward the plunger. The method of claim 4, wherein The other end of the locking member is formed with a curved surface, And an inclined surface formed at an end portion of the sleeve extending into the support cylinder to guide the sleeve to smoothly enter between the locking member and the support cylinder.

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