JPS6235637Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a negative pressure booster that boosts the master cylinder of an automobile's hydraulic brake, clutch, etc. using negative pressure. and a rear bowl-shaped body, the rear surface of the rear bowl-shaped body is overlapped with the front of the vehicle body wall, and both bowl-shaped bodies are connected to each other and the rear bowl-shaped body and the vehicle body wall via a tie rod that passes through the booster piston. Regarding the improvement of the valve cylinder that is integrated with the booster piston and is slidably supported on the rear wall of the rear bowl-shaped body, the tie rod through hole of the rear bowl-shaped body is sealed in the dust-proof boot that protects the valve cylinder from dust. It is an object of the present invention to provide the negative pressure type booster which is provided with a packing part and an annular seal part and which can be assembled efficiently.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In Fig. 1, W indicates a car body wall that constitutes the rear wall of the engine room of an automobile, and the negative pressure booster S of the present invention is attached to the front of the wall. , a brake master cylinder M is installed in front of this booster S.

The booster shell 1 of the booster S is composed of a pair of front and rear bowl-shaped bodies 1A and 1B that are butted against each other and connected by a tie rod 2, which will be described later.
and a piston diaphragm 4 having an inner circumferential bead 4a fixed to its rear surface, the piston diaphragm 4 is divided into a first working chamber A at the front and a second working chamber B at the rear.
is fixed to. The booster piston 3 is integrally formed with a valve cylinder 5 that protrudes in the axial direction from the rear surface of its central part, and the valve cylinder 5 is mounted on a flat bearing 6 fixed to the rear extension cylinder 1a of the rear bowl-shaped body 1B. It is slidably supported, and a sealing member 7 is attached to the outside of the flat bearing 6. The first working chamber A is always in communication with a negative pressure source (not shown) via the negative pressure introduction pipe 8, and the second working chamber B is
Communication with the first working chamber A or the atmosphere can be alternately switched via a control valve (not shown) operated by an input punch 9 fitted in the valve cylinder 5, and the input punch 9 is connected to a brake pedal. Operated by P. When the second working chamber B is communicated with the atmosphere, thrust is applied to the booster piston 3 due to the pressure difference between the working chambers A and B, and the master cylinder M is actuated by the forward movement of the booster piston 3.

The front bowl-shaped body 1A and the rear bowl-shaped body 1B are connected via one or more tie rods 2 passing through the booster piston 3 in the axial direction as follows.

A tie rod 2 is attached to the inner surface of the rear wall of the rear bowl-shaped body 1B.
A support tube 10 that passes through the tie rod 2 is welded, a flange 11 integrally projecting from the outer periphery of the tie rod 2 is fitted into the support tube 10, and a stop ring 12 is secured to the inner wall of the support tube 10 on the outside of the flange 11. Thus, the connection position of the tie rod 2 with the rear bowl-shaped body 1B is established by fitting the flange 11 and the support tube 10, and the retaining ring 12 prevents the flange 11 from coming off, so that the tie rod 2 is properly and immovable. is held in an upright position.

Next, a spring receiving plate 14 that supports the fixed end of the return spring 13 of the booster piston 3 is fixed to the front end of the tie rod 2 with a stop ring 15. When fitted, they abut against the inner surface of the front wall of the front bowl-shaped body 1A. Front bowl-shaped body 1
In order to seal the tie rod through hole A, an elastic seal member 17 is fitted into an annular housing 16 formed in the spring receiving plate 14.

Mounting bolts 18 and 19 are formed at both ends of the tie rod 2, which protrudes outward from the front and back of the booster shell 1. It penetrates and Natsu 2 is at the tip.
By tightening and screwing together the tie rod 2, the spring receiving plate 14, the front bowl-shaped body 1A and the mounting flange 2.
The four parts of 0 are connected together.

The outer periphery of the valve cylinder 5 is surrounded by a rubber dustproof boot 22, whose rear opening is fitted into the rear outer peripheral surface of the valve cylinder 5, and whose front opening is fitted into the outer peripheral surface of the rear extension cylinder 1a. A gasket part 23 is connected to the front opening edge of the dustproof boot 22, and the gasket part 23
A thick-walled annular seal portion 24 is integrally formed therein.

The seal portion 24 is fitted onto the outer peripheral surface of a rear mounting bolt 19, and the bolt 19 is passed through the vehicle body wall W, and by screwing and tightening a nut 29 to its tip, the tie rod 2, the rear bowl-shaped body 1B, and the vehicle body are secured. The three parts of the wall W are connected together. Also, the packing part 2
3 is sandwiched between the rear surface of the rear bowl-shaped body 1B and the front surface of the vehicle body wall W, and the seal part 24 is pushed into the tie rod through-hole 25 of the rear bowl-shaped body 1B, so that the through-hole 25 is inserted into the seal part 23. The seal is reliably sealed by the cooperation of the seal portion 24 and the seal portion 24.

The tie rod 2 is surrounded by a bellows-shaped telescopic boot 26 in the first working chamber A, and the front end of the boot 26 is tightly fitted to the outer periphery of the tie rod 2, and the rear end is connected to a booster piston 3 that is penetrated by the tie rod 2. It is tightly fitted into the through hole 27 of. Therefore, the elastic boot 26 seals the through hole 27 without interfering with the operation of the booster piston 3 due to its elasticity. Furthermore, since the annular thick wall portion 4c around the tie rod through hole 28 of the piston diaphragm 4 comes into close contact with the rear end surface of the telescopic boot 26 when the booster piston 3 moves forward, the first and second working chambers A and B are reliably isolated. In addition, when the booster piston 3 is operated manually with no negative pressure acting on the first working chamber A, when the air in the first working chamber A is compressed, the annular thick walled part 4c expands and contracts. It is spaced apart from the rear end surface of the boot 26 to allow the increase in air pressure in the first working chamber A to escape to the second working chamber B, allowing the manual operation to be performed easily.

As described above, according to the present invention, the dustproof boots 22
Since the seal part 23 is connected to the front opening edge of the tie rod 2, and the annular seal part 24 is integrally formed with the seal part 23, it is easy to fit the annular seal member, which is a small part, to the tie rod 2 even if they are separate parts. There are no problems caused by forgetting to do this, or forgetting to insert a thin gasket between the rear bowl-shaped body 1B and the vehicle body wall W, and these can be assembled efficiently. Furthermore, since the packing part 23 is interposed between the rear surface of the rear bowl-shaped body 1B and the front surface of the vehicle body wall W, even if the booster shell 1 vibrates while the vehicle is running, it will not directly rub against the vehicle body wall W. Therefore, even if the booster shell 1 is made of a thin steel plate to reduce its weight, problems such as damage to the booster shell and rust occurring from that part will not occur.

[Brief explanation of the drawing]

The drawings show an embodiment of the device according to the present invention, and FIG. 1 is a longitudinal sectional side view, and FIG. 2 is an enlarged longitudinal sectional side view of the main parts. W...Car body wall, S...Negative pressure booster, 1...
Booster shell, 1A...front bowl-shaped body, 1B...
Rear bowl-shaped body, 2... Tie rod, 3... Booster piston, 5... Valve cylinder, 22... Dust-proof boots, 2
3... Packing part, 24... Annular seal part, 25
...Tie rod through hole.

Claims (1)

[Scope of utility model registration request] A booster shell 1 that houses a booster piston 3 is divided into a front cup-shaped body 1A and a rear cup-shaped body 1B, the rear surface of the rear cup-shaped body 1B is overlapped with the front surface of a body wall W, and the two cup-shaped bodies 1A, 1B are connected to each other and the rear cup-shaped body 1B is connected to the body wall W via tie rods 2 that pass through the booster piston 3, and a valve cylinder 5 that is integral with the booster piston 3 is slidably supported on the rear wall of the rear cup-shaped body 1B.
A stretchable dustproof boot 22 is placed over the portion of the valve cylinder that protrudes from the rear cup-shaped body 1B.
a packing portion 23 connected to the front opening edge of the rear cup-shaped body 1B is sandwiched between the rear cup-shaped body 1B and the vehicle body wall W,
The annular seal portion 24 formed in the packing portion 23
A negative pressure booster in which the booster is tightly fitted to the outer circumferential surface of the tie rod 2.