JPH077239Y2 - Hydraulic booster - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a hydraulic booster for assisting the operation of a master cylinder in a brake device of a vehicle or the like, and in particular,
The present invention relates to a technique in which a bleeder mechanism is provided in a cylinder body portion of an apparatus.

[Prior art]

This type of hydraulic booster itself is disclosed in, for example, Japanese Patent Laid-Open No. 1-11.
As shown in Japanese Patent No. 9465, it is well known in the past. In the brake fluid pressure circuit to which the master cylinder belongs, the hydraulic fluid deteriorates due to heat generated in the wheel cylinders or other influences, or air is mixed into the hydraulic fluid. It is usually exchanged at times. Therefore, in order to replace the hydraulic fluid, conventionally, a brake fluid pressure circuit to which the master cylinder belongs is always provided with a bleeder mechanism capable of discharging the hydraulic fluid to the outside. In that respect, no such bleeder mechanism is provided on the hydraulic booster side. The hydraulic fluid on the booster side is a lifetime product, and its replacement has never been considered.

[Problems to be solved by the device]

However, it has been found that the cylinder body of the hydraulic booster that is separably connected to the master cylinder, and particularly the so-called stab type structure, has the following disadvantages. Here, the piercing type structure is one in which the end of the piston on the master cylinder side is inserted into the cylinder body of the booster so as to pierce it, and is connected to the output rod of the booster inside the cylinder body. Say. That is, even if the hydraulic fluid in the brake hydraulic circuit to which the master cylinder belongs is drained by the existing bleeder mechanism, the hydraulic fluid on the hydraulic booster side cannot be completely drained, so the master cylinder must be removed from the booster side. There is a disadvantage that the hydraulic fluid remaining in the drain chamber of the booster spills from the joint with the master cylinder and stains the surroundings when removing the booster. In addition, apart from that, in the one that shares the hydraulic fluid reservoir for the hydraulic booster with the master cylinder,
There is also a problem that when the hydraulic fluid on the master cylinder side is replaced, the old hydraulic fluid on the booster side mixes with the new hydraulic fluid.

[Outline of the device]

This invention breaks the conventional concept and provides a hydraulic booster with a bleeder mechanism that allows the hydraulic fluid in the drain chamber to be discharged to the outside. As a result, the hydraulic fluid in the drain chamber of the booster can be drained, and the problems of liquid leakage and the mixing of old hydraulic fluid can be solved at once. In particular, in this invention, the bleeder mechanism is arranged below the lower edge of the opening in consideration of the relationship with the opening on the drain chamber side of the booster that is closed by the piercing-type master cylinder. for that reason,
With the bleeder mechanism, the hydraulic fluid in the drain chamber of the booster can be effectively drained, and even when the master cylinder is removed, the fluid does not leak from the opening.

【Example】

First Embodiment ... See FIG. 1. The hydraulic booster 10 has a piercing-type master cylinder 50 to be assisted at one end, and a hydraulic fluid reservoir 70 shared with the master cylinder 50 at the upper side. I am carrying. The cylinder body 11 of the booster 10 has a mounting flange 12 for mounting on the vehicle body and a coupling portion 13 for receiving a part of the master cylinder 50. Inside the cylinder body 11, there is a servo piston 16 having a supply valve 14 and a discharge valve 15 inside, and an output rod 17 connected to the end of the servo piston 16. Supply valve 14 inside the servo piston 16
Is closed when the brake is not activated, but the input rod 18 receives pedal force from the pedal when the brake is activated.
The hydraulic pressure from the pump (not shown) is introduced into the servo chamber 19 as the servo pressure corresponding to the pedaling force. As a result, the servo piston 16 is assisted by receiving this servo pressure, and the assisted force is applied to the master cylinder 50 side through the output rod 17. On the other hand, contrary to the supply valve 14, the discharge valve 15 inside the servo piston 16 is closed when the brake is operated and is opened when the operation is stopped. When the drain valve 15 is opened, the pressure fluid in the servo chamber 19 is returned to the hydraulic fluid reservoir 70 through the drain chamber 20 around the output rod 17. Further, the drain chamber 20 has an end 61a of the first piston 61 protruding from the opening 52 of the cylinder body 51 of the master cylinder 50. The end portion 61a of the first piston 61 has a cylindrical shape, and the output rod 17 of the booster 10 is inserted into the recessed portion inside thereof, and the outer periphery thereof is sealed by a cup seal 80. The master cylinder 50 is a tandem type, and inside the cylinder body 51, there is a second piston 62 in addition to the first piston 61, which allows the first hydraulic chamber 63a and the second hydraulic chamber 63a to be provided. The hydraulic chamber 63b is partitioned. Now, a booster device in which the opening 52 of the master cylinder 50 enters.
Note the ten joints 13 of the ten. In this coupling portion 13, it is the cup seal 80 that seals between the master cylinder 50 side and the booster 10 side. Cup seal 80 is a booster
Inward flange 21 and chrysanthemum washer on the inner circumference of 10 cylinder body 11
Held between 22 and. Due to the sealing action of the cup seal 80, the hydraulic fluid remains inside the drain chamber 20 of the booster 10 even if the hydraulic fluid on the master cylinder 50 side is completely extracted. Therefore, the master cylinder 50
When the hydraulic pump 10 is taken out from the booster 10 side, the opening that allows the working fluid in the drain chamber 20 to form the connecting portion 13 (the inner peripheral opening of the cup seal 80)
It will spill and stain the surrounding area. Therefore, here, the bleeder mechanism 100 is provided in the lower portion of the cylinder body 11 so that the hydraulic fluid in the drain chamber 20 is also drained before the master cylinder 50 is removed. The bleeder mechanism 100 is composed of a known bleeder screw, and by loosening the screw, the drain chamber 20 can be easily communicated to the outside through a drain port 101 provided in the cylinder body 11 and a passage in the bleeder screw. In this case, since the bleeder mechanism 100 can also drain the hydraulic fluid on the booster 10 side, the old hydraulic fluid on the booster 10 side can be included in the new hydraulic fluid replaced in the hydraulic fluid reservoir 70. Mixing can also be avoided. Second Embodiment: See FIG. 2 In the first embodiment, the bleeder mechanism 100 is installed in the cylinder body 11
Although it is provided entirely below, it may be subject to restrictions such as the mounting position. Considering such cases,
In the second embodiment, the bleeder mechanism 100 having the same structure is arranged at the lower part of the cylinder body 11 but at the side. In this example, the drain port 102 at the tip of the bleeder mechanism 100 is mounted on the cylinder body 1 when mounted on the vehicle body.
It is important to set it so that it is located below the inner wall of 1 or the inner diameter of the assembly parts such as the cup seal 80. Third Embodiment ... See FIGS. 3 and 4 In the third embodiment, the master cylinder 50 and the booster 10 are provided.
The seal of the connecting part of the cylinder body of the master cylinder 50
This is done by an O-ring 83 provided on the outer periphery of the opening 52 of 51. Therefore, the drain chamber 20 of the booster 10 is connected to the connecting portion 13
Contact room 130 on the inner circumference of. Therefore, in this example, the drain port 10 is provided at the lower part of the coupling portion 13 of the cylinder body 11.
3 is provided, and the drain port 103 is closed by the bleeder mechanism 300. The bleeder mechanism 300 includes a screw member 302 having a passage 301 having an L-shaped cross section, and a gasket 303 for sealing the head of the screw member 302. In the third embodiment, the C-ring as shown in FIG.
304 is used as a spring bearing on the booster 10 side. Fourth Embodiment See FIGS. 5 to 7 In the fourth embodiment, the bleeder mechanism on the booster 10 side is configured by using existing parts. That is, although there is already a pipe 400 that connects the hydraulic fluid reservoir 70 and the drain chamber 20 of the booster 10, the nipple 402 as a connecting tool at one end of the pipe 400 is used as a bleeder mechanism. Therefore, the nipple that uses the bleeder mechanism
The mounting position of 402 is similar to that of the second embodiment. In this example, the filter device 410 is provided at the other end of the pipe 400 facing the supply port 403. This filter device 410 has a support frame 411 whose outer shape is a truncated cone,
In addition to the filter element 412 held by the support frame 411, the spring 413 for pressing the support frame 411 against the bottom of the hydraulic fluid reservoir 70 and the like. The spring 413 is supported between the support frame 411 side and the rib 71 of the hydraulic fluid reservoir 70, and normally covers the supply port 403 of the hydraulic fluid reservoir 71 with the portion of the support frame 411. However, when the filter element 412 is clogged, the pressure difference generated before and after the filter element 412 causes the portion of the support frame 411 to pop up, so that the return of the liquid is always ensured.

[Effect of device]

According to this invention, by providing the bleeder mechanism 100, 300, 402 also at a specific position on the hydraulic booster 10 side, it is possible to effectively solve the problem of liquid leakage and the problem of mixing old working liquid.

[Brief description of drawings]

1 is an overall sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view showing a second embodiment, and FIG. 3 is a sectional view showing a third embodiment. FIG. 4 is a view showing a part of the third embodiment, FIG. 5 is a cross-sectional view showing the fourth embodiment, and FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. And, FIG. 7 is a sectional view taken along the line VII-VII of FIG. 10 …… hydraulic power booster, 11 …… cylinder body, 16 …… servo piston, 19 …… servo chamber, 20 …… drain chamber, 50…
… Master cylinder, 70… Hydraulic fluid reservoir, 100, 300, 40
2 …… Bleeder mechanism.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A servo having a cylinder body that is detachably connected to a master cylinder and is fixed to a vehicle body, in which hydraulic pressure from a pump is introduced as servo pressure according to an operation input. Chamber, a servo piston that operates the master cylinder by receiving the servo pressure of the servo chamber, and a drain chamber into which the pressure liquid discharged from the servo chamber flows, the drain chamber is provided to the pump. In the hydraulic booster, the drain chamber is connected to a hydraulic fluid supply chamber, and the drain chamber is provided with an opening that is sealed and closed from the outside by coupling the master cylinder to the cylinder body. A bleeder mechanism that allows the working fluid in the chamber to be discharged to the outside is provided in the lower portion of the cylinder body, and the bleeder mechanism is provided in the drain chamber. Hydraulic booster is positioned lower than the lower edge of the mouth.