JPH0542944Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydraulic pressure booster for a fluid brake.

[Conventional technology]

Conventionally, there are Japanese Patent Publications No. 16194/1982 and No. 28868/1989 as hydraulic pressure boosters for fluid brakes.

The hydraulic pressure booster described in Japanese Patent Publication No. 52-16194 is shown in Fig. 6. In the normal state shown in Fig. 6, the piston of the master cylinder (not shown) is A high-pressure flow path 11 connected to the power piston 10 by a connecting member 85 and connected to a high-pressure fluid source via a high-pressure port 86.
A ball valve 83 abuts against a valve seat 84 in order to close the valve. Then, the inner member 81 is separated from the ball valve 83, the flow path 16 connects the pressure chamber 45 and the low pressure port 80, and the pressure chamber 45 is in a pressureless state.

When the push rod 37 is pushed in, the tip of the inner member 81 first comes into contact with the ball valve 83, closing the flow path 16 connecting the pressure chamber 45 and the low pressure port 80. Furthermore, when the inner member 81 is pushed, the ball valve 83
moves away from the valve seat 84, opens the high pressure flow path 11, and connects the pressure chamber 45 with the high pressure fluid source.

Then, the high-pressure fluid flowing into the pressure chamber 45 pushes the power piston 10 to the left in the figure, pushes the piston of the master cylinder (not shown) via the connecting member 85, and sends the fluid in the master cylinder to the wheel cylinder.

At the same time, the high pressure fluid in the pressure chamber 45 pushes the outer member 82 to the right in the figure, so that the push rod 37 transmits a pressure proportional to the hydraulic pressure in the pressure chamber 45 to the driver.

The hydraulic booster described in Japanese Patent Publication No. 49-28868 introduces a high-pressure fluid source into a pressure chamber, presses a power piston, and presses a piston in a master cylinder, similar to the device shown in Fig. 6. The high-pressure passage connecting the pressure chamber and the high-pressure fluid source and the passage connecting the pressure chamber and the low-pressure port are opened and closed by spool valves, and the flow rate is proportional to the hydraulic pressure in the pressure chamber. This is a device that can transmit the applied pressure to the driver.

[Problem that the invention attempts to solve]

The conventional device shown in FIG.
The device described in Publication No. 28868 is smaller than a type of booster that uses air pressure differences, and like boosters that use air pressure differences, it is proportional to the pressing force of the piston. It is convenient because it can transmit the reaction force.

However, the conventional device shown in FIG. 6 directly presses the valve seat 84 that opens and closes the high-pressure flow path 11 in the sliding direction of the inner member 81, thereby increasing the sliding speed of the inner member 81 and the moving speed of the ball valve. are equal, the pressure within the pressure chamber 45 rises rapidly.

Further, as described above, since the pressure within the pressure chamber 45 increases rapidly, the reaction force transmitted to the push rod 37 also increases rapidly. Then, the forward speed of the push rod 37 decreases, and the increase in the hydraulic pressure in the pressure chamber 45 slows down, so the hydraulic pressure in the pressure chamber 45 changes in a linear fashion. This causes the brakes to change, making it difficult to operate the brakes smoothly.

The hydraulic booster described in Japanese Patent Publication No. 49-28868 uses a spool valve, so the fitting part of the spool valve requires precision machining.
Furthermore, if the gap between the fitting parts changes depending on the liquid temperature, liquid leakage may occur.

This invention was made in view of the above matters,
A technical problem is to create a hydraulic booster that can be miniaturized, operates smoothly, does not require high-precision machining, can be manufactured at low cost, and does not leak.

[Means for solving problems]

In the present invention, a master cylinder 6 is slidably inserted into a cylinder member 1 and a master cylinder 6 is attached to the tip of the cylinder member 1.
Power piston 1 to which piston 61 of 0 is connected
0 and the pressure chamber 4 behind this power piston 10
5 and a supply valve 12 provided to open and close a flow path 16 connecting the pressure chamber 45 and the reservoir 50. When the return valve 29 is closed and the supply valve 12 is opened, the pressure chamber 45 is closed and the supply valve 12 is opened. 45 is configured to introduce high pressure fluid. A valve sleeve 25 is slidably inserted into the power piston 10 and is urged toward the rear side of the power piston 10 by a spring 28. Further, the supply valve 12 is made of a ball biased by a spring 14 so as to close the high-pressure passage 11, and the valve sleeve 25 is provided with a ball that presses the supply valve 12 when the valve sleeve 25 moves forward. A cam portion 26 for opening the flow path 11 is provided. Further, the spring 14 that biases the supply valve 12 is a ring-shaped leaf spring that is installed in an annular groove 10B provided around the power piston 10 to press and bias the supply valve 12 in the closing direction. A positioning protrusion 1 that has guide portions 14B on both sides of the above-mentioned portion and that slides into contact with the inner wall of the annular groove 10B, and that is inserted into a positioning hole 10C provided in the annular groove 10B.
It has 4C.

[Effect]

When a brake pedal (not shown) is stepped on, the valve sleeve 25 connected to the brake pedal advances to the left in the figure, and the return valve 29 closes the flow path 16 connecting the pressure chamber 45 and the reservoir 50.

When pushed further, the cam 26 of the valve sleeve 25 pushes the supply valve 12 open and opens the pressure chamber 4.
5 and the high-pressure fluid source 51 are in communication, and the high-pressure fluid is passed from the high-pressure fluid source 51 to the passage between the cylinder member 1 and the power piston 10, the outer periphery of the supply valve 12, and the cam 2 of the valve sleeve 25.
6 into the pressure chamber 45.

Since the supply valve 12 is pushed open by the cam 26, it is opened gently on the slope of the cam 26.
The pressure in the pressure chamber 45 also increases continuously, and the power piston 10 is pushed to the left in the figure by a force proportional to its diameter and the hydraulic pressure in the pressure chamber 45, pushing the piston 61 of the master cylinder 60 forward. The liquid in the master cylinder 60 is pumped to the oil cylinder 64.

〔Example〕

FIG. 1 shows an embodiment of the hydraulic booster of the present invention, in which a fixing ring 2 and a cylinder member 1 are inserted into an outer cylinder 5 connected to a master cylinder 60, and a cylinder member 1 is inserted from the rear of the cylinder member 1. A cylinder end member 43 is fitted through the piston contact member 42 and fixed from the outside with a screw ring 44.

A power piston 10 is slidably inserted into the cylinder member 1. A pressure chamber 45 is formed between the rear of the power piston 10 and the end of the cylinder member 1.

A piston 61 of a master cylinder 60 is connected to a recess 10A at the tip of the power piston 10, and a valve sleeve 25 biased by a return spring 28 is slidably inserted into the power piston 10. .

A return valve 29 biased by a bias spring 30 is provided at the tip of the valve sleeve 25, and this return valve 29 is a valve that can open and close the flow path 16 connecting the pressure chamber 45 and the reservoir 50. The flow path 16 connects the pressure chamber 45 to the reservoir 50 through the gap between the power piston 10 and the valve sleeve 25 and the passage 61A in the piston 61. A valve 17 is provided.

Further, the power piston 10 is provided with a supply valve 12 that can open and close a high-pressure passage 11 that connects a pressure chamber 45 and a high-pressure fluid source (accumulator) 51. This high pressure flow path 11 connects the pressure chamber 45 to a high pressure fluid source (accumulator) 51 via a gap between the power piston 10 and the valve sleeve 25 and a gap between the cylinder member 1 and the power piston 10.

The high pressure fluid source (accumulator) 51 is the pump 5
2, and the pump 52 is connected to the reservoir 50. Supply valve 12 is power piston 1
The outer circumference of the valve sleeve 2 is held down by a ring-shaped leaf spring 14 surrounding the outer periphery of the valve sleeve 2.
5 and prevents rattling while the vehicle is running. The ring-shaped leaf spring 14 is installed in an annular groove 10B provided around the power piston 10, and presses and biases the supply valve 12 in the closing direction. And a ring-shaped leaf spring 1
4 is divided into 8 parts, one part is cut out, and supply valves 12 are placed on both sides of the remaining 7 parts.
Guide portions 14B are provided on both sides of the portion that comes into contact with the annular groove 10B, and the guide portions 14B are in sliding contact with the inner wall of the annular groove 10B. Then, one guide portion 14B is connected to the supply valve 1.
The ring-shaped leaf spring 14 is placed in a position corresponding to 2.
is attached to the annular groove 10B. A positioning hole 10C is provided in the annular groove 10B of the power piston 10 so that the ring-shaped leaf spring 14 is locked in this mounting position, and a positioning protrusion 14C is inserted into the positioning hole 10C. It is provided in a protruding manner on the ring-shaped plate spring 14.

In addition, a cam 26 provided on the valve sleeve 25
By sliding the valve sleeve 25,
The slope of the cam 26 is formed to smoothly push open the supply valve 12 via the ball 13.

A stopper 35 is attached to the back surface of the valve sleeve 25 facing the pressure chamber 45. The stopper 35 is held down by a stopper receiver 19 attached to the power piston 10, and the sliding range of the valve sleeve 25 is limited by the stopper 35 and the stopper receiver 19. is restricted. The front end of a reaction piston 36 is in contact with the rear surface of the valve sleeve 25 via a stopper 35, and the reaction piston 36 is provided so as to be able to slide freely. are connected.

Then, as the valve sleeve 25 moves forward, first,
The flow path 16 is closed and the supply valve 12 is then opened. Further, the member indicated by the reference numeral 3 provided at the joining portion of each part is a seal ring.

Furthermore, the part shown as the tandem type master cylinder 60 has an already known structure, and includes a primary piston 61 and a secondary piston 6.
1', a return spring 62, and a valve 63, and pumps liquid to the wheel cylinder 64.

Next, the operation will be explained.

FIG. 1 shows the push rod 37 returned to the right side of the figure and the hydraulic booster inactive. In this state, the pressure chamber 45 and the high pressure fluid source (accumulator) 51 are connected. High pressure channel 11
is closed by the supply valve 12, and the return valve 29 of the flow path 16 connecting the pressure chamber 45 and the reservoir 50 is opened, so that the pressure chamber 45 communicates with the reservoir 50.

In this state, when the push rod 37 is pushed to the left in the figure using a brake pedal (not shown), the reaction piston 36 moves forward, the valve sleeve 25 moves forward, and the return valve 29 closes the pressure chamber 45 and reservoir 50. The connecting channel 16 is closed.

Further, when the push rod 37 is pushed forward, the cam 26 of the valve sleeve 25 moves to the supply valve 1.
2 is pushed open and the high pressure passage 11 connecting the pressure chamber 45 and the high pressure fluid source 51 communicates with each other, and the high pressure fluid is passed from the high pressure fluid source 51 to the cylinder member 1 and the power piston 1.
The pressure chamber 4 passes through the passage between 0, the outer circumference of the supply valve 12, and the side of the cam 26 of the valve sleeve 25.
5.

When the supply valve 12 is opened, the ring-shaped leaf spring 14 expands in the direction in which its diameter increases, that is, in the normal direction, allowing the supply valve 12 to open.
Since the ring-shaped leaf spring 14 slides along the inner wall of the ring, the ring-shaped leaf spring 14 moves smoothly. This also applies when the ring-shaped leaf spring 14 contracts, that is, when the supply valve 12 closes, so the supply valve 12
Opening and closing are performed smoothly due to the presence of this ring-shaped leaf spring 14. Further, since the positioning protrusion 14C is inserted into the positioning hole 10C, the ring-shaped plate spring 14 does not rotate around the power piston 10. For this reason, the ring-shaped leaf spring 14 may cause malfunction of the power piston 10, or the notch portion of the ring-shaped leaf spring 14 may come to the position of the supply valve 12, preventing the supply valve 12 from being seated and closed. No accidents will occur.

Since the supply valve 12 is pushed open by the cam 26, it is opened gently on the slope of the cam 26.
The pressure in the pressure chamber 45 also increases continuously, and the power piston 10 is pushed to the left in the figure by a force proportional to its diameter and the hydraulic pressure in the pressure chamber 45, pushing the piston 61 of the master cylinder 60 forward. The liquid in the master cylinder 60 is pumped to the oil cylinder 64.

At the same time, the hydraulic pressure within the pressure chamber 45 acts on the reaction piston 36 as a reaction force proportional to the diameter of the reaction piston 36 and the hydraulic pressure within the pressure chamber 45.

Next, when the brake pedal is stopped and the pressing force of the push rod 37 is removed, the valve sleeve 25 is returned to its original position by the return spring 28, the supply valve 12 closes the high pressure flow path 11, and then the return valve 29 closes the flow path. 16 is opened, and the power piston 10 is inserted into the piston 6 in the master cylinder 60.
1 returns, and the fluid in the pressure chamber 45 returns to the reservoir 50 through the flow path 16 and further through the check valve 17.

FIG. 5 shows a hydraulic booster according to another embodiment of the present invention, and the same parts as those in the embodiment shown in FIG.

In this embodiment, the outer cylinder connected to the master cylinder 60 is referred to as the cylinder member 1, and the joint portion between the cylinder end member 43 and the cylinder member 1 is omitted in FIG. 5.

Then, the piston 61 engages with the power piston 10 via the piston receiver 15, and the power piston 10 is urged by the return spring 18 whose one end is in contact with the spring contact ring 4, and the return spring 62 of the master cylinder 60 is urged. The check valve 17 is removed from the flow path 16 connected to the reservoir 50, and the part of the valve sleeve 25 that holds the return valve 29 is formed as a valve holding cylinder 27 separately from the valve sleeve 25. .

The device of this second embodiment is similar to the device of the first embodiment except that the fluid in the pressure chamber 45 returns directly to the reservoir 50 through the flow path 16 without going through the check valve 17.

[Effect of idea]

According to the present invention, the supply valve 12 for opening and closing the high-pressure flow path 11 is formed separately from the return valve 29 and is opened by the cam 26, so that when the supply valve 12 is opened, the pressure chamber 45 Since the hydraulic pressure does not rise stepwise but in a continuous linear manner, the hydraulic pressure booster operates smoothly and the reaction force transmitted to the driver via the push rod 37 is also smooth. . Furthermore, the loss stroke from closing the return valve 29 to opening the supply valve 12 can be freely designed.

Unlike the spool valve, it does not require high-precision machining, can be manufactured at low cost, and has excellent liquid tightness due to the seating of the supply valve 12, with no liquid leakage. Since this supply valve 12 is seated by a ring-shaped leaf spring 14, the structure around the supply valve 12 can be simplified, and the diameter of the power piston 10 does not need to be increased. Further, the ring-shaped leaf spring 14 is connected to the guide portion 14.
B, it moves smoothly and the supply valve 12 opens and closes smoothly. Moreover, since rotation is prevented by the positioning protrusion 14C, malfunction can be avoided.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a front view of a ring-shaped leaf spring, and Fig. 3 is a sectional view thereof.
FIG. 4 is an enlarged sectional view of the mounting portion, FIG. 5 is a sectional view of another embodiment, and FIG. 6 is a sectional view of a conventional example. 1...Cylinder, 10...Power piston, 1
0B...Annular groove, 10C...Positioning hole, 11...
...High pressure channel, 12... Supply valve, 14B...
...Guide part, 14C...Positioning protrusion, 16...
Flow path, 25... valve sleeve, 26... cam,
28...Return spring, 29...Return valve, 50...Reservoir, 51...High pressure fluid source, 60...Master cylinder, 61...Piston.

Claims (1)

[Scope of utility model registration request] A power piston 10 that is slidably inserted into the cylinder member 1 and connected to the piston 61 of the master cylinder 60 at its tip, a pressure chamber 45 behind the power piston 10, and a pressure chamber 45 and a reservoir. Flow path 16 connecting with 50
and a supply valve 12 provided to open and close, and when the return valve 29 closes and the supply valve 12 opens, the pressure chamber 4
A valve sleeve 25 is slidably inserted into the power piston 10 and is urged toward the rear side of the power piston 10 by a spring 28. The valve sleeve 25 includes a cam that presses the supply valve 12 and opens the high pressure flow path 11 when the valve sleeve 25 moves forward. a spring 14 for biasing the supply valve 12;
is an annular groove 1 provided around the power piston 10
The ring-shaped leaf spring 14 is installed in the inside of the annular groove 10B and presses and biases the supply valve 12 in the closing direction. Part 14B
A hydraulic booster characterized in that it has a positioning projection 14C inserted into a positioning hole 10C provided in an annular groove 10B.