JPH04193662A - Control valve of hydraulic pressure booster - Google Patents

Abstract

PURPOSE:To achieve further miniaturization of a booster without deteriorating the responsiveness of the booster by providing a control valve with a supply passage, and making the supply passage open to the inside of a shaft hole on the valve seat side of a line which passes the center of a ball valve being seated on a valve seat and which is perpendicular to the axis of the shaft hole. CONSTITUTION:A stepped sleeve 13 is integrally mounted on the power piston 2 of a hydraulic booster and the left end portion of the sleeve 13 is fitted into a shaft hole 2a in such a manner as maintaining the sealed state of liquids and a first valve seat 15 constituting a control valve 14 is provided at the left end portion of the sleeve 13 and a ball valve 16 is provided within the shaft hole 2a. A collar 20 is provided on the left side of the ball valve 16 within the shaft hole 2a and a pressure chamber 21 is defined between the collar 20 and the first valve seat 15 and communicated with a pump 31 via a supply passage 27, a circular channel 28, a radial passage 29 and a conduit 30. The supply passage 27 is formed as a radial through hole penetrating the inside of the shaft hole 2a from three equally spaced positions on the outer peripheral face of the power piston 2 and is opened to the inside of the shaft hole 2a on the first valve seat 15 side of a line passing the center of the ball 16a of the ball valve 16 and being perpendicular to the axis of the shaft hole 2a.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a hydraulic booster used in a brake booster or the like, and more particularly to a control valve for a hydraulic booster.

[Conventional technology]

A control valve of a hydraulic booster generally includes a shaft hole formed in the shaft of a power piston and communicating with a power chamber formed at an end of the power piston, and a first valve seat provided in the shaft hole. ,
a ball valve provided in the shaft hole and seated on a first valve seat from the side opposite to the power chamber to close the shaft hole; A supply passage for supplying pressure fluid to the ball valve side; an annular pin for introducing the fuel into the power chamber; a discharge passage provided on the shaft of the annular pin and communicating the power chamber with the reservoir; and an annular pin provided at the tip of the annular pin, the annular pin corresponding to the ball valve. The second valve seat is provided with a second valve seat that blocks communication between the power chamber and the discharge passage when they come into contact with each other. In the control valve of this type of hydraulic booster, when the brake pedal or clutch pedal is released, the annular pin is separated from the ball valve and communicates the power chamber with the reservoir via the discharge passage. A ball valve is also seated on the first valve seat to prevent pressure fluid from being introduced into the power chamber from the supply passage. On the other hand, when the pedal is depressed and the annular pin moves the ball valve away from the first valve seat, the second valve at the tip of the annular pin
Since the valve seat is seated on the ball valve, communication between the power chamber and the reservoir is cut off, and when the ball valve is unseated from the first valve seat, pressurized fluid is introduced into the power chamber, so that the fluid pressure causes the power to be increased. The piston can be moved forward.

[Problem to be solved by the invention]

By the way, in the conventional control valve of a hydraulic pressure booster, the supply passage opens into the shaft hole on the side opposite to the first valve seat of the ball valve, so when the ball valve opens, Fluid pressure flowing into the shaft hole from the supply passage flows into the power chamber through a gap between the outer surface of the ball valve and the inner surface of the shaft hole, and a gap between the ball valve and the first valve seat. Ta. As a result, especially when the inner diameter of the shaft hole is made smaller in order to downsize the hydraulic booster, the gap between the outer surface of the ball valve and the inner surface of the shaft hole becomes smaller, and the flow path is narrowed in this area. A drawback has arisen in that responsiveness deteriorates.

[Means to solve the problem]

In view of the above-mentioned circumstances, the present invention has provided that the supply passage is located on a line passing through the center of the ball valve and perpendicular to the axis of the shaft hole when the ball valve is seated on the first valve seat.
It opens into the shaft hole on the valve seat side.

[Effect]

According to the above configuration, when the ball valve opens, the fluid pressure flowing into the shaft hole from the supply passage does not flow through the gap between the outer surface of the ball valve and the inner surface of the shaft hole as in the conventional case. , it immediately flows into the power chamber through the gap between the ball valve and the first valve seat. Therefore, even if the inner diameter of the shaft hole is made small (and the gap between the outer surface of the ball valve and the inner surface of the shaft hole is made extremely small), the flow path will not be constricted in this area and the response will not deteriorate. It is possible to further downsize the hydraulic pressure booster compared to the above.

[Embodiment] The present invention will be described below with reference to the illustrated embodiment. A power piston 2 is slidably fitted in a housing l of a hydraulic booster, and a bushing rod is provided at the left end of the power piston 2. 3 is held fluid-tight and slidably protrudes outside the housing 1, and its tip is interlocked with a piston of a mask cylinder (not shown). The right end opening of the housing 1 is sealed by a plug 4, and a power chamber 5 into which pressure oil is introduced is formed between the plug 4 and the power piston 2. Further, a spring 7 is housed in a low pressure chamber 6 formed on the opposite side of the power chamber 5 of the power piston 2, and the elastic force of the spring 7 normally moves the power piston 2 to the non-operating position shown in the figure, where it comes into contact with the plug 4. keeping. And a low pressure chamber 6 housing the spring 7
is in communication with a reservoir 10 via a passageway 8 and a conduit 9 formed in the housing 1 . A shaft hole 2a with a bottom is formed in the shaft portion of the power piston 2, and the right end portion of the shaft hole 2a opens into the power chamber 5. A stepped sleeve 13 is integrally attached to the power piston 2, and the left end of the sleeve 13 is fitted into the shaft hole 2a in a fluid-tight manner, and a control valve 14 is formed at the tip thereof. A first valve seat 15 is provided. A ball valve 16 is provided in the shaft hole 2a, and the ball valve 16 is seated on the first valve seat 15 from the side opposite to the power chamber 5 by a spring 17 to close the shaft hole 2a. . In the illustrated embodiment, the ball valve 16 includes a ball 1
6a and a shaft body 16b that integrally supports this. A collar 20 is provided in the shaft hole 2a on the left side of the ball valve 16 in a liquid-tight manner, and a pressure chamber 21 is formed between the collar 20 and the first valve seat 15. A balance chamber 22 is formed in the left side of the power chamber 5, and the balance chamber 22 is connected to the power chamber 5 through a communication passage 23 formed in the power piston 2 and a through hole 24 formed in the sleeve 13.
It communicates with Then, the shaft body 16b constituting the ball valve 16 is slidably penetrated through the collar 20 while maintaining liquid tightness, and the balance chamber 2
2, and the pressure receiving area in the balance chamber 22 of the shaft body 16b and the area of the inner diameter of the first valve seat 15, that is, the ball 1
By making the pressure receiving area of 6a on the power chamber 5 side substantially the same, the ball valve 16 is prevented from being displaced forward or backward even if the pressure within the power chamber 5 and the balance chamber 22 fluctuates. There is. The pressure chamber 21 is connected to a supply passage 27 formed in the power piston 2, an annular groove 28 formed on the outer peripheral surface of the power piston 2, a radial passage 29 formed in the housing 1, and further connected to this passage 29. It is communicated with a pump 31 via a conduit 30, so that the pump 31 can constantly supply pressure oil at a predetermined pressure into the pressure chamber 21. Furthermore, an input shaft 34 linked to a brake pedal (not shown) is slidably fitted into the plug 4, and an annular pin 3 constituting the control valve 14 is attached to the tip of the input shaft 34.
5 is installed. In the non-operating state shown in the figure, in which the brake pedal (not shown) is released, the input shaft 34 is biased rightward by the spring 36 loaded between the input shaft 34 and the sleeve 13, and the annular pin 35 is pressed against the ball valve. It is separated from 16. In this state, the discharge passage 3 formed in the shaft of the annular pin 35
7 communicates with the power chamber 5, a passage 38 formed in the shaft portion of the input shaft 34, a passage 39 formed in the plug 4,
Passage 40 formed in housing 1 and above-mentioned passage 8
The power chamber 5 is communicated with the reservoir 10 via the power chamber 5, thereby communicating the power chamber 5 with the reservoir 10. In response to this, the brake pedal is depressed and the input shaft 3
4 is moved forward, the ball valve 16 is brought into contact with the second valve seat 41 formed at the tip of the annular pin 35 to cut off communication between the discharge passage 37 and the power chamber 5, and the annular pin 35 allows the ball valve 16 to be forcibly removed from the first valve seat 15 against the spring 17. As a result, the pressure oil that has always been introduced into the pressure chamber 21 is introduced into the power chamber 5 through the gap between the outer periphery of the annular pin 35 and the inner periphery of the sleeve 13. Similar to the conventionally known hydraulic pressure booster,
Braking can be performed by advancing the power piston 2 to the left at a predetermined boost ratio. By the way, as shown in FIGS. 2 and 3, the supply passage 27 is configured as a radial through hole that penetrates into the shaft hole 2a at three equally spaced positions on the outer peripheral surface of the power piston 2. , and each supply passage 27 is connected to the ball valve 16
When the ball 16a is seated on the first valve seat 15, an opening is opened into the shaft hole 2a on the side of the first valve seat 15 from a line A passing through the center O of the ball 16a and perpendicular to the axis of the shaft hole 2a. I'm letting you do it. Therefore, the input shaft 34 is moved forward and the annular pin 35
When the ball valve 16 is moved away from the first valve seat 15 against the spring 17, the pressure oil flowing into the shaft hole 2a from the supply passage 27 immediately flows between the ball 16a and the first valve seat 15. It flows into the power chamber 5 through the gap between the outer periphery of the annular pin 35 and the inner periphery of the sleeve 13 . As a result, as shown by the imaginary line B in FIG. The pressure oil flowing into the ball valve 16 does not flow through the gap δ between the outer surface of the shaft body 16b and the inner surface of the shaft hole 2a. Therefore, even if the inner diameter of the shaft hole 2a is made small (and the above-mentioned gap δ is made extremely small), the flow path will not be constricted in this part and the response will not deteriorate, and the hydraulic pressure will be boosted compared to the conventional one. It is possible to further downsize the device. [Effects of the Invention] As described above, according to the present invention, a hydraulic booster that is smaller than conventional devices and has good responsiveness can be provided. The effect is that it can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
An enlarged view of the main part of the figure, Figure 3 is I I I-I of Figure 2
FIG. 2 is a sectional view taken along line II. 1...Housing 2...Power piston 2a
...Shaft hole 5...Power chamber lO...Reservoir 14...Control valve 15...First valve seat
16...Ball valve 16a...Ball 1
6b...Shaft body 21...Pressure chamber 27...
Supply passage 34...Input shaft 35...Annular pin 37...Discharge passage 41...Second valve seat patent applicant Jidosha Kiki Co., Ltd.

Claims (1)

[Scope of Claims] A shaft hole formed in the shaft portion of the power piston and communicating with the power chamber formed at the end of the power piston, a first valve seat provided in the shaft hole, and a first valve seat provided in the shaft hole. a ball valve that is provided in the power piston and seats on the first valve seat from the side opposite to the power chamber to close the shaft hole; It is operated in conjunction with a supply passage for supplying fluid and an input shaft, and contacts the ball valve from the power chamber side to displace the ball valve from the first valve seat and introduce the pressure fluid into the power chamber. an annular pin provided on the shaft of the annular pin to communicate the power chamber with the reservoir; and an annular pin provided at the tip of the annular pin to release the power when the annular pin abuts the ball valve. In a control valve for a hydraulic booster equipped with a second valve seat that blocks communication between a chamber and a discharge passage, the supply passage is connected to the ball valve when the ball valve is seated on the first valve seat. A control valve for a hydraulic pressure booster, characterized in that the control valve is opened into the shaft hole on the first valve seat side from a line passing through the center and perpendicular to the axis of the shaft hole.