JPS624049Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hydraulic booster used to lighten the operation of the brake pedal or clutch pedal of an automobile. This invention relates to a hydraulic booster with an improved regulator valve for securing operating pressure.

The present invention is directed to a cylinder body, an input piston slidably penetrating one end wall of the cylinder body, an output member slidably fitted to the other end of the cylinder body, and an input piston inside the cylinder body. a hollow power piston that is slidably fitted between the input piston and the output member to divide the inside of the cylinder body into an operating hydraulic chamber on one end side and a drain chamber on the other end side; It consists of a control valve that is inserted into the hole from the other end of the power piston and slidably fitted to the other end of the inner hole, and the control valve is pushed toward the input piston by a spring when the input piston is not in operation. This closes the hydraulic passage to the working hydraulic chamber, but it is pressed by the forward motion of the input piston and moves toward the output piston against the spring, forming a hydraulic passage that communicates the input piston and the working hydraulic chamber. This is a type of device that increases the hydraulic pressure in the hydraulic pressure chamber.

In the hydraulic booster 3 configured as described above,
In order to prevent other hydraulic devices from becoming inoperable due to the pump discharge pressure reaching its relief pressure due to booster operation, a relief system is provided that releases any more pressure oil when the pressure in the operating hydraulic chamber 15 reaches a predetermined value. A valve 47 is provided within the spool 41, and a drain passage 50 from the relief valve 47 is provided on the outer periphery of the regulator valve 30, as shown in FIG. For this reason, not only is a portion of the wall of the second cylinder 40 required to provide the drain passage 50, but also one end of the drain passage must be closed with a plug and the second
A groove must be provided on the cylinder peripheral wall surface to communicate with the relief valve in the spool, complicating the manufacturing process.

Therefore, an object of the present invention is to provide a hydraulic booster that has a simple drain passage configuration, is easy to manufacture, and is compact in size. This is achieved by providing a through hole in the spool that communicates with the small diameter end of the spool, and allowing the small diameter end of the spool to slidably communicate with a drain hole bored in the cylinder end of the regulator.

Embodiments of the present invention will be described below based on the drawings. In order to simplify the explanation, an example will be given in which the hydraulic booster according to the present invention is used to control the operation of a wheel brake cylinder, but the hydraulic booster according to the present invention is limited to such applications only. Of course, it can also be used for other hydraulically operated devices.

In Figs. 1 and 2, reference numeral 1 denotes a reservoir, 2 denotes a hydraulic pump incorporating a relief valve, 3 denotes a hydraulic booster, 4 denotes a power steering (with an open center type valve incorporated), and 5 denotes a wheel brake cylinder.

The hydraulic booster 3 is adapted to actuate the wheel brake cylinder 5 in response to actuation of the brake pedal 6. This hydraulic booster 3 is
Mainly a cylinder body 7 and an input piston 8 slidably fitted to one end of the cylinder body.
, an output piston (output member) 9 fitted to the other end inside the cylinder body 7, and both pistons 8 and 9.
and a power piston 10 fitted within the cylinder body 7. Cylinder body 7
is open at one end (towards the right in the figure),
A plug 11 serving as an end wall of the cylinder body 7 is fitted and fixed within this opening. The input piston 8, which slidably passes through the plug 11, has an outer end connected to the brake pedal 6 via a rod 12, and a hollow small diameter portion 13 at the cylinder side tip. The inner hole 14 of this tip small diameter portion 13 is connected to the input piston 8.
and the power piston 10 .

The power piston 10 is a hollow member slidably fitted into the cylinder body 7, and divides the inside of the cylinder body 7 into an operating hydraulic chamber 15 on the right side and a drain chamber 16 on the left side. A control valve 18 is slidably fitted into the inner hole 17 of the power piston 10 from the left side, and an input piston return spring 20 is installed in a drain chamber 19 provided further outside the inner hole. The left end of the input piston 8 is pressed in the direction of the brake pedal 6. control valve 1
8 is a hollow cylindrical member having a through hole 26 in the axial direction, and a control valve pressing spring 22 provided between the left end of the control valve 18 and the inner end of the output piston 9.
As a result, the tapered surface 24 of the annular projection 23 of the control valve 18 is pressed against the valve seat 25 of the power piston 10. The right end surface 21 of the control valve 18 is tapered so as to come into contact with the small diameter portion 13 at the tip of the input piston 8 . A concave groove 27 is provided on the outer peripheral surface of the power piston 10, and a protrusion 2 of the control valve 18 is disposed within the concave groove 27.
A passage 29 is provided that communicates with the groove 28 at the right end of 3. Since the concave groove 24 of the power piston is formed long in the axial direction, even if the main booster 3 is operated and the power piston 10 slides to the left as described later, the regulator valve 30 and check valve 31 will not be closed. The oil that has passed can be supplied to the control valve 18 and the hydraulic pressure chamber 15. Furthermore, the power piston 10 is provided with a drain passage 32 communicating with the drain chamber 19.

The output piston 9 is attached to the shoulder 33 of the cylinder body 7.
The output piston is always pressed to the right by an output piston return spring 36 disposed between a spring stopper 34 connected to the piston and a ring 35 provided at the right end of the piston. The space between the output piston 9 and the cylinder body 7 is a drain chamber 16 that communicates with the drain passage 32 of the power piston 10. A master cylinder 7a is located between the left end of the output piston and the cylinder body 7, and communicates with the operating cylinder 5 of the wheel brake via a residual pressure valve 39.

The regulator valve 30 provided at the top of the booster 3 is for securing the operating pressure of the booster when other hydraulic devices such as the power steering 4 are not operating.
and a spool 41 slidably fitted into the cylinder 40. The second cylinder 40 has an opening 42 that introduces oil sent from the hydraulic pump 2, an opening 43 that diverts oil to other hydraulic devices such as the power steering 4, and a booster inlet 4.
4, these openings communicate with each other through a groove 45 on the outer periphery of the spool 41, and the discharge hydraulic pressure of the hydraulic pump 2 is controlled by the size of a throttle 46 between the groove 45 and the opening 43. The spool 41 has an inner hole 48 in which a relief valve 47 is built in at the right end, and a drain passage 50 that penetrates from the left end of the inner hole 48 to the end of the small diameter portion (spool guide) 49 at the tip of the spool 41. The right end of the cylinder 40 is sealed by a plug 51, and a chamber 52 formed between the inner hole of the plug 51 and the right end of the spool 41 is
It communicates with the hydraulic pressure chamber 15 and communicates with the hydraulic pressure chamber 15 via the relief valve 47 of the spool inner hole 48 and the passage 53 . A spool pressing spring 54 is built in this chamber 52 and operates to press the spool 41 to the left and narrow the throttle 46. On the other hand, the flange 55 of the spool 41 is provided with an orifice, and the spool 41 is moved to the right by the hydraulic pressure blown by the pump that passes through the orifice 56 and presses the flange 55 to the right. Spool 41
The relief valve 47 in the inner hole includes a valve seat 58 that is fitted and fixed in the right end of the inner hole of the spool 41 and receives the ball valve 57, a ball valve 57, a holder 59 that supports the ball valve 57, and a holder 59. Seat 58 through ball valve 57
It consists of a spring 59 that presses against.

Next, the operation of the hydraulic booster according to the present invention will be briefly explained.

First, when the pedal 6 is not depressed and therefore the input piston 8 is in the position shown in FIG. The protruding tapered surface (sliding surface) 24 of is pressed against the valve seat 25 of the power piston 10. Therefore, from the hydraulic pump 2 to the regulator valve 30 and check valve 3.
1. Oil that has reached the groove 28 of the control valve 18 through the outer groove 27 of the power piston 10 and the passage 29 cannot enter the hydraulic pressure chamber 15.

Therefore, the oil discharged from the hydraulic pump 2 is
After passing through the throttle 46 of the regulator valve 30 and being supplied to other hydraulic equipment such as the power steering 4, it is recovered to the reservoir 1 again. When the hydraulic equipment 4 is in a non-operating state, the discharge oil pressure of the hydraulic pump 2 is controlled by the function of the regulator valve 30 to a low set pressure corresponding to the force of the spring 54.

Next, when the pedal 6 is depressed and the rod 12 and input piston 8 move to the left against the force of the input piston return spring 20, the tip surface of the input piston 8 comes into contact with the right end surface 26 of the control valve 18. , after the inner hole 14 of the input piston 8 is shut off from the drain chamber 19 in the power piston 10, the control valve 1 is closed against the pressing force of the control valve pressing spring 22.
Move 8 to the left. Therefore, the right end portion of the output piston 9 and the inner hole portion 17 of the power piston
A passage 29 communicates with a chamber formed by
Through the inner hole 1 of the small diameter part of the tip of the input piston 8
4 into the hydraulic pressure chamber 15. Therefore, the pressure in the working hydraulic chamber 15 increases, and in response to this pressure increase, the regulator valve 30 increases the pump discharge pressure, so that the power piston 10 and the output piston 9
moves to the left against the output piston return spring 36. Therefore, the oil in the master cylinder 7a is sent to the wheel brake cylinder 5 through the residual pressure valve 39 to operate the wheel brake. In short, by simply stepping on the brake pedal 6 with a small force, the wheel brake can be operated by the boosting action of the present booster device.

Next, when the brake pedal 6 is stopped being depressed, the input piston 8 and the rod 12 are moved to the right by the return spring 20. Therefore, the passage from the passage 29 of the power piston 10 to the hydraulic pressure chamber 11 is closed as shown in FIG. 2, and the inner hole 14 of the input piston 8 communicates with the drain chamber 19. Therefore, the output piston 8 and the power piston 10 are connected to the output piston return spring 3.
6, the oil in the hydraulic working chamber 15 flows to the reservoir 61 through the drain passage 32 of the power piston 10 and the drain chamber 16.

Next, the operation of the regulator valve 30 will be briefly described. When the other hydraulic devices 4 are in a non-operating state and the brake pedal 6 is not depressed, the operating hydraulic pressure chamber 1
When oil is not supplied to the pump 5, the oil passing through the orifice 55 of the spool 41 from the pump 2 moves the spool 41 to the right against the force of the spool pressing spring 54, so the throttle 46 becomes wider. The oil pressure in the groove 45, that is, the pump discharge oil pressure, is regulated to a low set pressure corresponding to the force of the spring 54.

Next, as already mentioned, when the brake pedal 6 is depressed and oil is supplied to the hydraulic pressure chamber 15 of the booster, the chamber 5 in which the spring 54 is housed
2 is in communication with the hydraulic pressure chamber 15 of the booster 3 via the passage 53, so when the booster 3 operates, the pressure in the hydraulic chamber 15 increases and the spool 4
1 is moved to the left and operates to further narrow the throttle 46 and increase the pump discharge pressure. Therefore, booster operating pressure is ensured.

As already mentioned, a relief valve 47 is built into the spool 41 of the regulator valve 30, and when the pressure in the hydraulic pressure chamber 15 of the booster 3 exceeds a predetermined value, the pressure is released through the relief valve 47. This prevents the pump discharge pressure from reaching the pump relief pressure and enables the hydraulic device 4 to operate. That is, when the pressure in the hydraulic pressure chamber 15 exceeds a predetermined value, the oil in the hydraulic pressure chamber 15 flows to the drain reservoir 61 through the relief valve 47 and the drain passage 50 in the spool 41 . That is, there is a drain passage 50 in the center of the left end wall of the spool 41.
is a drain discharge hole that passes through the center of the spool guide 49 that passes through the left end wall of the second cylinder (regulator), opens to the outside of the second cylinder, and is coaxially formed at the left end of the cylinder body. A drain discharge path is formed to the drain reservoir 61 via the drain hole 62 .

This drain discharge hole 62 is formed coaxially with the second cylinder 40 in the cylinder body forming the left end mirror part, but this hole is used for cutting and discharge when drilling the second cylinder 40. can be used as is as the drain discharge hole 62, which is extremely easy to manufacture.

Further, the drain passage 51 at the left end of the spool 41 can also be used as the drain passage 51 using a hole used as a cut discharge hole when the inner hole 48 is bored.

The above configuration of the regulator valve 30, particularly its drain path configuration, not only makes the regulator valve 30 more compact, but also greatly simplifies the number of manufacturing steps. Thus, in the hydraulic booster 3 according to the present invention, with the above configuration, the pressure relief valve 47 of the booster operating hydraulic chamber 15 and its drain passage 50 are provided in the spool 41 of the regulator valve 30, so that the overall size of the booster 3 is reduced. Becomes compact,
It also became easier to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional hydraulic booster, and FIG. 2 is a sectional view of a hydraulic booster according to the present invention. 7...Cylinder body, 8...Input piston, 9
...Output piston, 10...Power piston, 1
5... Working hydraulic chamber, 18... Control valve, 30... Regulator valve, 47... Relief valve, 50... Drain passage.

Claims (1)

[Claims for Utility Model Registration] A cylinder body, an input piston slidably penetrating one end wall of the cylinder body, an output member slidably fitted to the other end of the cylinder body, and a cylinder body; a hollow power piston that is slidably fitted between an input piston and an output member in the main body to divide the inside of the cylinder body into an operating hydraulic pressure chamber on one end side and a drain chamber on the other end side; The control valve is inserted into the inner hole of the piston from the other end of the power piston and is slidably fitted to the other end of the inner hole, and the control valve is operated by a spring when the input piston is not in operation. It is pressed toward the input piston, closing the hydraulic passage to the hydraulic pressure chamber, but when the input piston moves forward and is pressed by the input piston and moves toward the output member against the spring, there is a gap between the input piston and the input piston. A hydraulic booster of a type that communicates with an operating hydraulic chamber is provided with a regulator valve that divides oil from the hydraulic pump into the main booster and other hydraulic devices, and the regulator valve is connected to a cylinder adjacent in parallel to the cylinder of the booster; It consists of a spool that is slidably fitted inside the second cylinder, and the peripheral surface of this spool is connected to the inlet of the passage from the pump, the outlet of the passage to other hydraulic equipment, and the hydraulic pressure supply port to the booster. A groove is provided, and the spool is applied with the force of a spring and the hydraulic pressure of the booster operating hydraulic chamber at one end, and is pressed by the pump discharge pressure acting on the piston surface opposite the spring, and the balance of these forces causes the other hydraulic pressure to be applied. A relief valve connected to the booster operating hydraulic chamber is built in the spool center hole, and the drain passage of the relief valve extends through the small diameter portion at the tip of the second cylinder. A hydraulic booster characterized in that the opening is opened outside the second cylinder.