JPH037652A - Liquid pressure booster - Google Patents

Abstract

PURPOSE:To quicken the rise of a liquid pressure actuator by connecting a piping leading therefrom to the pressure chamber of a master cylinder with the power chamber of a liquid pressure booster device. CONSTITUTION:The power chamber 14 of a liquid pressure booster device 1 passes through a passage 72 formed in a housing 2 and is connected with pipings 62, 64 of No.1 and No.2 brake system. When a brake pedal is stamped, an input shaft 16 moves left to cause a sphere 32 to separate immediately from a valve seat 34, and the liquid pressure in a pressure chamber 37 is introduced into the power chamber 14. Thereby a power piston 7 is moved ahead to cause output of an output shaft 41 so as to advance pistons 43, 58 of a master cylinder 42, and No.1 and No.2 pressure chambers 59, 61 are isolated from a reserver 31. Meantime the liquid pressure introduced to the power chamber 14 flows into the pipings 62, 64 via a passage 72 and conduits 73, 74. This causes immediate absorption of the lost stroke of the brake system to enable a quick rise of the brake liquid pressure, so that the brake application will be put in effect in earlier stage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic booster used in a brake booster, etc., which performs servo control of input and output at a predetermined servo ratio. be.

(Prior Art) In general, a hydraulic booster is disclosed in Japanese Patent Application Laid-open No. 61-94865, for example.
As shown in the publication, a power piston slidably fitted into a housing, a power chamber into which hydraulic pressure acting on one end of the power piston is introduced, and this power chamber and a hydraulic pressure source or It includes a control valve that switches and controls communication with the reservoir, an input shaft that operates the control valve, and an output shaft that is connected to the power piston. By operating the input shaft and switching the control valve, hydraulic pressure from a hydraulic pressure source is introduced into the power chamber, and the hydraulic pressure operates the power piston to output from the output shaft. By operating the piston of the master cylinder using the output of the hydraulic pressure booster, the master cylinder generates hydraulic pressure, and the generated hydraulic pressure operates an actuated device such as a wheel cylinder. .

In that case, the hydraulic booster performs so-called servo control, which controls the magnitude of the output of the output shaft in response to the magnitude of the input of the input shaft.

(Problem to be solved by the invention) By the way, in such a conventional hydraulic booster,
There are various losses in the hydraulic circuit after the master cylinder due to play in the hydraulic actuator, so even if the input shaft is activated, the actuated device does not immediately generate hydraulic pressure, and the hydraulic pressure does not rise. There was a problem with being late.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a hydraulic booster that can speed up the start-up of a hydraulic actuator.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a method for connecting a pipe connecting a pressure chamber of a master cylinder to a hydraulic actuator to a power chamber of a hydraulic booster. It is characterized by what it does.

In that case, the cylinder diameter of the master cylinder is set smaller than the cylinder diameter of the power chamber, and a check valve is installed in the conduit connecting the piping and the power chamber to allow fluid to flow only from the power chamber toward the piping. I am trying to intervene.

(Function) In the hydraulic pressure booster according to the present invention having such a configuration, the power piston is operated by the hydraulic pressure introduced into the power chamber by the operation of the input shaft, and this operation increases the output. Since the piston of the master cylinder operates via the shaft, hydraulic pressure is generated within the pressure chamber of the master cylinder.

At the same time, the hydraulic pressure introduced into the power chamber is also introduced into the piping. Therefore, the hydraulic pressure in the pipe increases rapidly, and the hydraulic actuator quickly starts operating. When the hydraulic pressure in the piping rises to a predetermined level, the cylinder diameter of the pressure chamber of the master cylinder is set smaller than the cylinder diameter of the power chamber, so the master cylinder hydraulic pressure becomes larger than the hydraulic pressure in the power chamber. This master cylinder hydraulic pressure is then introduced to the actuated device. In that case, the check valve prevents the hydraulic fluid from flowing back from the piping side to the power chamber side.

In this manner, in the hydraulic pressure booster of the present invention, the hydraulic pressure rises quickly at the initial stage of operation.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a hydraulic booster according to the present invention applied as a brake booster.

As shown in FIG. 1, the brake booster 1 includes a housing 2 formed in a substantially cylindrical shape. The housing 2 has a first hole 3 opened at the right end of the housing 2, a second hole 4 formed continuously with the first hole 3, and a third hole 5 opened at the left end of the housing 2 coaxially. Each is drilled. Further, a partition wall 6 is formed between the second hole 4 and the third hole 5.

A power piston 7 is slidably fitted into the second hole 4 in a liquid-tight manner. Further, the power piston 7 is coaxially formed with fourth and fifth holes 8 and 9 that open at the left and right ends, respectively.

A plug 10 for liquid-tightly closing the first hole 3 is fixed to the right end of the housing 2 by a nut 11. Also,
The middle part 12 of the plug 10 fits in the second hole 4 in a liquid-tight manner, and the left end part 1.3 of the plug 10 projects into the fourth hole 8 of the power piston 7. A power chamber 14 is formed between the plug 10 and the power piston 7.

A sixth hole 15 is bored in the plug 1.0 coaxially with the fourth and fifth holes 8 and 9. An input shaft 16 is slidably fitted into the sixth hole 15 in a fluid-tight manner. A flange portion 17 is formed at the left end of the input shaft 16.
When the plug moves backward, that is, moves to the right, the right side of the flange portion 17 comes into contact with the left end of the plug 10.
The input shaft 16 cannot be moved to the right any further. That is, this position is the retraction limit position of the input shaft 16. Further, the flange portion 17 is connected to a stepped portion 18 between the fourth hole 8 and the fifth hole 9 and the power piston 7.
The flange portion 17 is disposed between the ring-shaped retaining member 19 attached to the retaining member 19 and the flange portion 17 comes into contact with the retaining member 19 when the input shaft 16 moves to the right with respect to the power piston 6. This prevents the input shaft 16 from being removed from the power piston 7. Therefore, between the stepped portion 18 and the retaining member 19, the flange portion 17
can move relative to the power piston 7. Furthermore, a cylindrical member 20 is provided at the left end of the input shaft 16.
is provided. On the other hand, the right end of the input shaft 16 is connected to a brake pedal (not shown) via a connecting member 21.

An axial passage 23 communicating with the hole 22 of the cylindrical member 20 is bored at approximately the center of the input shaft 16, and a diametric passage 24 communicating with the right end of this passage 23 is bored. . Which passage 24 communicates with an annular groove 25 formed between the plug 10 and the input shaft 16 .
communicates with an annular chamber 27 between the housing 2 and the plug 10 via a diametrical passage 26 drilled in the plug 10. Furthermore, the annular chamber 27 communicates via an axial passage 28 formed in the housing 2 with an outlet 29 , which in turn communicates with a reservoir 31 via an outlet conduit 30 .

A valve body 33 having a ball 32 at its right end is slidably disposed in the fifth hole 9 of the power piston 7 .

Further, a cylindrical valve seat member 34 is fixed at the right end of the fifth hole 9, and the ball 32 of the valve body 33 is seated on this valve seat member 34 by the biasing force of the compression coil spring 35. ing. Seal portion between ball 32 and valve seat member 34 and valve body 3
A pressure chamber 37 is defined by a seal member 36 that seals the pressure chamber 3 .

Further, the left end portion of the cylindrical member 20 is inserted into the hole 38 of the valve seat member 34 and is seated on the ball 32 when the valve seat member 34 is not in operation.

A compression coil spring 39 is disposed between the cylindrical member 20 and the valve seat member 34. This spring 39 constantly biases the input shaft 16 and the cylindrical member 20 in the direction in which the cylindrical member 20 moves away from the valve body 33, that is, in the right direction, and the force on the input shaft 16 is strong enough to overcome the biasing force of the spring 39. When no force to the left of the magnitude is applied, the input shaft 16 is set to the backward limit position. Then, the input shaft 16 is connected to the spring 3
When it moves forward, that is, to the left, with respect to the power piston 7 against the biasing force of the cylindrical member 20, the left end of the cylindrical member 20 touches the ball
2 is moved to the left and removed from the valve seat member 34, the pressure chamber 37 and the power chamber 14 are brought into communication. That is, the control valve 40 is constituted by the cylindrical member 20, the valve body 3'3 having the ball 32, and the valve seat member 34.

An output shaft 41 is formed at the left end of the power piston 7, and this output shaft 41 penetrates the partition wall 6 in a fluid-tight and slidable manner through a seal member 41a. Further, the output shaft 41 is in contact with a primary piston 43 of a tandem brake master cylinder 8-der 42 fixedly installed at the left end of the housing 2.

In that case, an adjustment member 44 screwed onto the tip of the output shaft 41
The distance between the output shaft 41 and the primary piston 43 is adjusted by. A double return spring 4 is disposed between the power piston 7 and the partition wall 6.
5, the output shaft 41 and the power piston 7 are biased to the illustrated backward limit position.

When the power piston 7 and the input shaft 16 are both at the retracting limit position, the flange portion 17 is spaced apart from the step portion 18 and the retaining member 19. That is, when the input shaft 16 is not in operation, the input shaft 16
When the flange portion 17 comes into contact with the left end portion of the plug 10, the retaining member 1 is held against the power piston 7.
9 and is held in a predetermined forward position away from 9. In this held position, the cylindrical member 20 at the left end of the input shaft 16
The left end of is in contact with the ball 32.

A passage 46 is formed in the power piston 7, and a chamber 47 formed on the left end side of the valve body 33 and the power chamber 14 communicate with each other.

The pressure chamber 37 is connected to the housing 2 through a passage 48.
It communicates with an annular groove 49 provided between the outer periphery of the piston 7 and the outer periphery of the piston 7 . Further, the groove 49 communicates with the supply port 52 via a hole 50 formed in the nozzle housing 2 and a filter 51. This supply port 52 communicates via a supply conduit 53 with an accumulator 54 and with the discharge side of a pump 55 , the suction side of which communicates with the reservoir 31 . The pump 55 and the pump 54 constitute the hydraulic pressure source of the present invention. Between the accumulator 54 and the pump 55,
A check valve 56 is provided that allows liquid to flow from the pump 55 toward the accumulator 54 but prevents liquid from flowing in the opposite direction.

On the other hand, a briary piston 43 and a secondary piston 58 are slidably fitted into the hole 57 of the master cylinder 42 . A first pressure chamber 59 is formed between both pistons 4358, and a secondary piston 5
A second pressure chamber 61 is formed between the left end of the cylinder 8 and the master cylinder end wall 6o. In that case, the cylinder diameter of each pressure chamber 59, 61 is set to be smaller than the cylinder diameter of the power chamber 14. The first pressure chamber 59 is connected to the first
It communicates with the wheel cylinders 63, 63 of the brake system (for example, the rear brake system). Further, the second pressure chamber 61 is connected to a wheel cylinder 65.6 of a second brake system (for example, a front brake system) through a pipe 64.
It is connected to 5.

A first return spring 66 is compressed between the primary piston 43 and the yakandari piston 58, and a second return spring 67 is compressed between the yakandari piston 58 and the master cylinder end wall 60. has been done. Additionally, the housing of the master cylinder 42 includes two pairs of in/1/2 for the first and second brake systems.
A return port 68, 69 and a return boat 70, 71 are formed, respectively. Each of these ports is connected to a reservoir 31.

Further, the power chamber 14 is connected to the piping 6 of the first and second brake systems via a passage 72 formed in the housing 2.
2.64 is connected. In that case, check valves 75 and 76 are interposed in the conduits 73 and 74 that connect the passage 72 and the pipes 62 and 64 to allow only the flow of hydraulic fluid from the power chamber 14 to the pipes 62 and 64. There is.

Next, the operation of this embodiment will be explained.

When the pump 55 is driven, the hydraulic fluid is introduced from the reservoir 31 into the accumulator 54 via the check valve 56, and the supply conduit 53, supply port 52, filter 51, and passage 50 are introduced into the accumulator 54.
, groove 49, and passage 48 into the pressure chamber 37. A constant level of hydraulic pressure is maintained in the pressure chamber 37 and the accumulator 54 at all times.

In the state where the puller 1/- key is not operated, the input shaft 16, the power piston 7, and the output shaft 41 of the brake booster 1 are all at the backward limit position. In this state, the ball 32 of the control valve 40 is seated on the valve seat member 34, and the cylindrical member 20 is seated on the ball 32.

Therefore, the power chamber 14 has a pressure chamber 37 and a reservoir 31.
is cut off from. Therefore, the inside of the power chamber 1.4 is maintained at a hydraulic pressure that is approximately balanced with the spring force of the return spring 45.

When the brake pedal (not shown) is depressed for braking, the input shaft 16 moves to the left and the ball 32 touches the valve seat member 34.
The engine immediately leaves the seat, and the pressure fluid in the pressure chamber 37 is introduced into the power chamber 14. This pressure fluid causes the power piston 7 to move forward against the elastic force of the spring 45, so that the output shaft 4 outputs an output to each piston 4 of the master cylinder 42.
Move forward 3,58. This isolates the first and second pressure chambers 59,61 from the reservoir 31.

On the other hand, the pressure fluid introduced into the power chamber 14 also flows into the pipe 62.64 via the passage 72 and the conduit 73.74. Therefore, any loss stroke in the brake system is absorbed immediately. Brake fluid pressure builds up quickly. Therefore, the brakes start working earlier.

When the brake fluid pressure starts to rise, the cylinder diameter of the mask cylinder pressure chamber 59, 61 is smaller than the cylinder diameter of the power chamber 14, so the brake fluid pressure becomes larger than the pressure in the power chamber, and the wheel cylinder 63. 65, the master cylinder 42 hydraulic pressure is introduced. In that case, the master cylinder hydraulic pressure is prevented from flowing back toward the power chamber 14 by the check valves 75 and 76. Therefore, there is no loss of brake fluid pressure.

On the other hand, since the hydraulic pressure within the power chamber 14 also acts on the input shaft 16, the force applied to the input shaft 16 due to this hydraulic pressure is transmitted to the driver as a brake reaction force.

As the power piston 7 moves, the valve seat member 34 also moves to the left, and when the valve seat member 34 comes into contact with the ball 32, communication between the pressure chamber 37 and the power chamber 14 is cut off. Therefore, no more pressure fluid is introduced into the power chamber 14, and the movement of the power piston 7 is stopped. As a result, pressurized fluid is introduced into the power chamber 14 in an amount corresponding to the amount of depression of the brake pedal, that is, the input from the input shaft 16. Therefore, the output of the output shaft 41 has a magnitude corresponding to the input of the input shaft 16. In this way, braking is performed with a braking force of a magnitude corresponding to the amount of pedal depression.

Further, the pressurized liquid in the power chamber 14 is also introduced into the chamber 47 through the passage 46. Since the hydraulic pressure in this chamber 47 comes to act on the left end of the valve body 33, the force applied to the valve body 33 due to the hydraulic pressure in the power chamber 14 is reduced and the valve body 33 does not move to the left. . This makes it unnecessary to increase the elastic force of the spring 35 so much.

When the brake pedal is released to release the brake operation, the input shaft 16 moves back significantly until the flange portion 17 contacts the retaining member 19 with respect to the power piston 7 . Therefore, the left end of the cylindrical member 20 separates from the ball 32, and the power chamber 14 communicates with the reservoir 31, reducing its pressure.

Therefore, the power piston 7 retreats due to the elastic force of the spring 45, and accordingly, the pressure fluid in the power chamber 14 is discharged to the reservoir 31. Also, in conjunction with the retreat of the power piston 7, both pistons 43 of the master cylinder 42.
Since 58 also moves backward, the hydraulic pressure in both pressure chambers 59 and 61 decreases, and the braking force becomes weaker.

As the input shaft 16 retreats, the cylindrical member 20 is largely separated from the ball 32 and a large flow path area is formed, so that the pressure fluid in the first and second power chambers 15.48 is quickly discharged to the reservoir 31. will be done.

Therefore, the power piston 7 quickly retreats.

When the flange portion 17 comes into contact with the left end of the plug 10, the input shaft 16 will no longer move back, and only the power piston 7 will move back. Therefore, the flange portion 17 becomes separated from the retaining member 19. When the right end of the power piston 7 comes into contact with the plug 10, the power piston 7 stops retracting and reaches the retracting limit position.

In this state, the input shaft is at a predetermined position advanced relative to the power piston 7, and the tip of the cylindrical member 20 is in contact with the ball 32.

The brake is thus quickly released.

In any of the above-mentioned embodiments, the present invention is applied to a brake booster, but it is applicable to other hydraulic pressure boosters other than the brake booster, such as a clutch booster. Needless to say, it can also be used.

(Effects of the Invention) As is clear from the above description, the hydraulic booster according to the present invention directs the pressure fluid introduced into the power chamber at the initial stage of operation into the piping connecting the master cylinder and the hydraulic actuator. Since the hydraulic pressure is also introduced, the hydraulic pressure in the master cylinder can be raised quickly.

Therefore, if the hydraulic pressure booster of the present invention is applied to, for example, a brake booster, it is possible to accelerate the start of brake effect, and it is possible to improve brake feeling.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment in which a hydraulic booster according to the present invention is applied to a brake booster. 1... Brake booster (hydraulic pressure booster), 2...
Housing, 6... Power piston, 15... Power chamber, 17... Input shaft, 31... Reservoir, 4
0... Control valve, 41... Output shaft, 42... Master cylinder, 59, 67... First and second pressure chamber, 6
2.64... Piping, 63.65... Wheel cylinder (hydraulic actuator), 73.74... Conduit

Claims (3)

[Claims] (1) The control valve is switched by the operation of the input shaft, and pressure fluid from the hydraulic pressure source is introduced into the power chamber, and the power piston is operated by the hydraulic pressure, which drives the piston of the master cylinder through the output shaft. In a hydraulic booster that is operated to generate hydraulic pressure and operate a hydraulic actuator using the hydraulic pressure, piping for introducing the hydraulic pressure of the master cylinder to the hydraulic actuator. and the power chamber are connected to each other. (2) The hydraulic pressure booster according to claim 1, wherein the cylinder diameter of the pressure chamber of the master cylinder is set smaller than the cylinder diameter of the power chamber. (3) A check valve is provided in a conduit connecting the piping and the power chamber to allow only flow of the working fluid from the power chamber toward the piping. 2. The hydraulic booster according to 2.