JPS6344293Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an assembly of a booster and a master cylinder, in which a cylinder body of a master cylinder is separably connected to the front surface of a booster shell of the booster.

In such a conventional assembly, the booster shell of the booster is divided into a front and a rear bowl-shaped body, and the opposite ends of the two bowl-shaped bodies are connected to each other so as to sandwich the outer peripheral end of the piston diaphragm in the booster shell. is fixed by fixing means such as bolts, and the mounting flange of the master cylinder is connected to the front bowl-shaped body by bolts. However, since the booster shell is designed to directly support the forward thrust load applied to the master cylinder when the booster is activated, the fixing means must be able to sufficiently withstand the thrust load. ,For this reason,
Inevitably, there is a problem in that the outer diameter of the booster shell, especially the outer diameter of the opposing ends of the front and rear bowl-shaped bodies, must be designed to be large.

Therefore, as shown in Japanese Utility Model Application Publication No. 55-46041, the front end of a tie rod that passes through the front and rear bowl-shaped bodies of the booster shell, the booster piston, and the mounting flanges of the master cylinder is fixed to the front bowl-shaped body, and then A nut is screwed and tightened at the end through a fixed wall such as the vehicle body to integrally connect the front and rear bowl-shaped bodies and the mounting flange to the fixed wall, so that when the booster is activated, the master cylinder The forward thrust load applied to the cylinder body is received by the fixed wall via the tie rod, eliminating the load burden on the booster shell, thereby reducing the thickness and weight of the booster shell and reducing the distance between the opposing ends of both bowl-shaped bodies. A booster and master cylinder assembly has already been proposed which eliminates the fixing means and allows the outer diameter of the booster shell to be reduced.

However, in the booster described in the above-mentioned publication, the rear bowl-shaped body and the fixed wall are jointly tightened with one nut at the rear end of the tie rod, and the booster is in a stand-alone state, that is, before it is attached to the fixed wall. In this state, the rear end of the tie rod is not fixed to the rear bowl-shaped body, so the rear end of the tie rod comes out forward from the rear bowl-shaped body, and the two bowl-shaped bodies do not have a fixing means between the opposing ends. For example, when transporting the booster alone or separating the booster from the fixed wall for inspection and maintenance, the booster shell may disintegrate spontaneously. There is.

The present invention has been proposed in view of the above, and can eliminate the drawbacks of the conventional ones, and moreover, the front bowl-shaped body of the booster shell can be used to prevent the elastic force of the return spring of the booster piston and the negative pressure inside the booster shell. It is an object of the present invention to provide an assembly of a booster and a master cylinder that is easy to assemble and prevents deformation due to bending.

In order to achieve such an object, the present invention constructs a booster shell of a booster into two halves with a front and rear bowl-shaped body having no fixing means between opposing ends, and houses a piston diaphragm whose outer peripheral end is sandwiched between the opposing ends of the two bowl-shaped bodies, and a booster piston which is connected to the inner peripheral end of the piston diaphragm and is capable of reciprocating back and forth, A negative pressure chamber is defined in front of the booster piston, a return spring is disposed in the negative pressure chamber to urge the booster piston in a backward direction, and a master cylinder is provided on the outer surface of the front wall of the front bowl-shaped body. and connecting the working piston of the master cylinder to the booster piston, connecting both bowl-shaped bodies and the mounting flange through tie rods passing through the bowl-shaped bodies, the mounting flange, and the booster piston. In the case where the tie rod is separably connected, the rear end of the tie rod is fixed to the rear bowl-shaped body, and a nut is screwed and tightened to the front end of the tie rod, and the tie rod is attached to the inner surface of the front wall of the front bowl-shaped body. A spring receiving plate that overlaps and supports the fixed end of the return spring is fixed, and a retaining ring facing the outer surface of the front wall of the front bowl-shaped body is removably locked to the tie rod; The present invention is characterized in that an annular recess for receiving a retaining ring is formed on the rear end surface of the mounting flange.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference numeral W indicates a car body wall which is the rear wall of an engine room of an automobile, and an assembly of a booster S and a brake master cylinder M is attached to the front surface of the car body wall.

The inside of the booster shell 1 of the booster S is composed of a booster piston 2 housed therein so as to be able to reciprocate back and forth, and a piston diaphragm 3 having an inner peripheral bead 3a attached to its rear surface. It is divided into a second working chamber B.

The first working chamber A is always in communication with a negative pressure source via the negative pressure introduction pipe 5, and constitutes the negative pressure chamber of the present invention.
Further, communication between the second working chamber B and the first working chamber A or the atmosphere can be alternately switched via a control valve (not shown) operated by an input rod 6 linked to the brake pedal P. In the first working chamber A, an output rod 7 is connected to the booster piston 2, and an operating piston 9 that slides on the cylinder body 8 of the master cylinder M is connected to the output rod 7. Also, a return spring 4 is installed in the first working chamber A to force the booster piston 2 backward. Therefore, if the second working chamber B is communicated with the atmosphere by forward movement of the input rod 6, the pressure difference generated between the working chambers A and B will give forward thrust to the booster piston 2, and this thrust will This makes it possible to drive the working piston 9 of the master cylinder M forward via the output rod 7.

The booster shell 1 consists of a front bowl-shaped body 1A and a rear bowl-shaped body 1B that are divided in the axial direction, and the outer peripheral bead of the piston diaphragm 3 is inserted between the opposing ends of these bowl-shaped bodies 1A and 1B that fit into each other. 3b is clamped in the radial direction. At that time, both bowl-shaped bodies 1A, 1
B is prevented from relative rotation by engagement with the positioning notch 10 and the pawl 11 at each opposing end, but no fixing means such as bolts are specially provided between the opposing ends.

The front bowl-shaped body 1A is open at the center of the front.
The rear end portion of the cylinder body 8 of the master cylinder M is fitted into the opening 12 via the seal member 13,
And a mounting flange 8a integrated with the cylinder body 8
is superimposed on the front surface of the front bowl-shaped body 1A. This mounting flange 8a, the front bowl-shaped body 1A and the rear bowl-shaped body 1
The three members B are integrally connected via one or more tie rods 14 passing through the booster piston 2 as follows.

A tie rod 1 is attached to the rear inner surface of the rear bowl-shaped body 1B.
A support tube 15 penetrating through the tie rod 14 is welded to the tie rod 14, and a stepped flange 16 formed on the outer periphery of the tie rod 14 is fitted into the support tube 15. In that case, stepped flange 1
6. An annular housing 17 defined by the support tube 15 and the rear wall of the rear bowl-shaped body 1B is fitted with an elastic sealing member 18 for sealing the tie rod through hole of the rear bowl-shaped body 1B. A retaining ring 1 that cooperates with this seal member 18 to clamp the large diameter portion of the stepped flange 16
9 is locked to the inner wall of the support tube 15. In this way, the rear end of the tie rod 14 is fixed to the rear bowl-shaped body 1B.

Further, a spring receiving plate 20 that supports the fixed end of the return spring 4 of the booster piston 2 is fixed to the front end of the tie rod 14 by a stop ring 21. The front bowl-shaped body 1 supports the inner surface of the front wall of the front bowl-shaped body 1A when the ends are fitted together.
Regulates the axial position of A. In order to seal the tie rod through hole of the front bowl-shaped body 1A, a spring receiving plate 20 is used.
An elastic seal member 23 is fitted into the annular housing 22 formed in the shape of the annular housing 22 . An annular groove 24 adjacent to the front bowl-shaped body 1A is formed on the outer periphery of a portion of the tie rod 14 that protrudes forward from the front bowl-shaped body 1A. A retaining ring 25 such as an E-ring is removably engaged with the outer surface of the front wall of the bowl-shaped body 1A to prevent the bowl-shaped body 1A from slipping out forward. Therefore, when separating the booster S and the master cylinder M, the front bowl-shaped body 1A will not be separated from the cylinder body 8 even by the frictional force of the seal member 13.

The mounting flange 8a of the master cylinder M and the front bowl-shaped body 1A are connected without being obstructed by the retaining ring 25.
An annular recess 26 for receiving the retaining ring 25 is formed on the rear end surface of the mounting flange 8a so as to obtain a proper overlapping state with the retaining ring 25.

Tie rod 14 has both front and rear ends attached with mounting bolts 14.
a, 14b, and after the front mounting bolt 14a passes through the mounting flange 8a,
The nut 27 is screwed and tightened. As described above, the two bowl-shaped bodies 1A, 1B and the mounting flange 8a are integrally connected via the tie rod 14, and an assembly of the booster S and the master cylinder M is obtained.

After the rear mounting bolt 14b of the tie rod 14 penetrates the vehicle body wall, it is screwed and tightened with the nut 28.
Thus, the booster S and the master cylinder M are supported at fixed positions on the vehicle body wall W.

The tie rod 14 is surrounded by a bellows-shaped telescopic boot 29 in the first working chamber A.
The front end of the booster piston 2 is tightly fitted to the outer periphery of the tie rod 14, and the rear end of the booster piston 2 is tightly fitted to the through hole 30 of the booster piston 2, which is passed through the tie rod 14. Therefore, the elastic boot 29 can fit through the through hole 3 without interfering with the operation of the booster piston 2 due to its elasticity.
Seal 0.

Therefore, when the booster S is activated, that is, when the booster piston 2 moves forward due to the pressure difference between the first and second working chambers A and B to drive the working piston 9 of the master cylinder M, the cylinder Although a forward thrust load is applied to the main body 8, this load is transmitted and supported by the vehicle body wall W via the tie rod 14, and the booster shell 1 is released from the thrust load. In addition, the elastic force of the return spring 4 of the booster piston 2 is also transferred to the tie rod 1 via the spring receiving plate 20.
4, the booster shell 1 is also released from the elastic force.

As described above, according to the present invention, the booster shell 1 of the booster is configured in half by the front and rear bowl-shaped bodies 1A and 1B, which have no fixing means between the opposing ends, and Inside the booster shell 1, there is a piston diaphragm 3 whose outer peripheral end is sandwiched between the opposing ends of the bowl-shaped bodies 1A and 1B, and a piston diaphragm 3 which is connected to the inner peripheral end of the piston diaphragm 3 and is capable of reciprocating back and forth. a booster piston 2, and defines a negative pressure chamber in front of the booster piston 2,
A return spring 4 is disposed in the negative pressure chamber to urge the booster piston 2 in the backward direction, and the mounting flange 8a of the master cylinder M is superimposed on the outer surface of the front wall of the front bowl-shaped body 1A. The operating piston 9 of the master cylinder M is connected to the booster piston 2.
in which the two bowl-shaped bodies 1A, 1B and the mounting flange 8a are separably connected via a tie rod 14 that passes through the two bowl-shaped bodies 1A, 1B, the mounting flange 8a, and the booster piston 2, The rear end of the tie rod 14 is connected to the rear bowl-shaped body 1.
A nut 27 is screwed and tightened to the front end of the tie rod 14, and a retaining ring 25 facing the outer surface of the front wall of the front bowl-shaped body 1A is removably locked to the tie rod 14. The ring 25 cooperates with the tie rod 14 whose rear end is fixed to the rear bowl-shaped body 1B, so that both the bowl-shaped bodies 1A and 1B of the booster shell 1 can always be connected inseparably. Even when the device is in a stand-alone state before being connected to a fixed wall such as a vehicle body or the master cylinder M, both the bowl-shaped bodies 1A and 1B do not have a fixing means between their opposing ends.
As a result, there is no risk that the booster shell 1 will be separated inadvertently, for example when transporting the booster alone or when separating the booster from the master cylinder or fixed wall for inspection and maintenance. Natural decomposition can be reliably prevented, and transport work and inspection and maintenance work can be performed efficiently and accurately.

Further, the retaining ring 25 is received in an annular recess 26 formed on the rear end surface of the mounting flange 8a, so when the mounting flange 8a is separated from the front bowl-shaped body 1A, the entire retaining ring 25 is inserted into the front bowl. Shape 1A
It can be exposed forward from the outer surface of the front wall of the
The work of attaching and detaching the retaining ring 25 to the tie rod 14 can be easily performed without being obstructed by the front bowl-shaped body 1A, which can contribute to improving the efficiency of the work of assembling the booster. Moreover, since the retaining ring 25 is received in the annular recess 26 when the mounting flange 8a is attached, it does not interfere with proper superposition of the mounting flange 8a and the front wall of the front bowl-shaped body 1A.

Furthermore, a spring receiving plate 20 is fixed to the tie rod 14, which overlaps the inner surface of the front wall of the front bowl-shaped body 1A and supports the fixed end of the return spring 4.
The spring receiving plate 20 is inseparably connected to the front bowl-shaped body 1A via the tie rod 14, and the rigidity of the front wall of the front bowl-shaped body 1A that overlaps with the spring receiving plate 20 can be greatly increased. In addition, the strong elastic force of the return spring 4 can be directly applied to the tie rod 14 to reduce the load on the front bowl-shaped body 1A. Therefore, even if the booster shell 1 is formed to be lightweight and thin,
There is no fear that the front bowl-shaped body 1A will be deformed by the elastic force of the return spring 4 or the large negative pressure of the negative pressure chamber A, and the booster shell 1 can be made even thinner and lighter. .

[Brief explanation of the drawing]

The drawing is a longitudinal sectional side view of the main parts of the assembly of the present invention. A... First working chamber as a negative pressure chamber, M... Master cylinder, S... Booster, 1... Booster shell, 1A... Front bowl-shaped body, 1B... Rear bowl-shaped body, 2 ... Booster piston, 3 ... Piston diaphragm, 4 ... Return spring, 8a ... Mounting flange, 9 ... Operating piston, 14 ... Tie rod, 20 ... Spring receiving plate, 25 ... Retaining ring, 26
...Annular recess, 27...nut.

Claims (1)

[Scope of utility model registration request] The booster shell 1 of the booster is assembled into a front and rear bowl-shaped body 1 having no fastening means between the opposite ends.
A piston diaphragm 3 is constructed in half from A and 1B, and inside the booster shell 1 is a piston diaphragm 3 whose outer peripheral end is inserted between the opposing ends of both the bowl-shaped bodies 1A and 1B.
and a booster piston 2 which is connected to the inner peripheral end of the piston diaphragm 3 and is capable of reciprocating back and forth, and defines a negative pressure chamber in front of the booster piston 2. , a return spring 4 that urges the booster piston 2 in the backward direction;
The mounting flange 8a of the master cylinder M is superimposed on the outer surface of the front wall of the front bowl-shaped body 1A, and the operating piston 9 of the master cylinder M is connected to the booster piston 2. body 1
A, 1B and the mounting flange 8a, both bowl-shaped bodies 1
A, 1B are separably connected via a tie rod 14 passing through the mounting flange 8a and the booster piston 2, in which the rear end of the tie rod 14 is fixed to the rear bowl-shaped body 1B and a nut 27 is attached to the front end thereof. A spring receiving plate 20 that overlaps the inner surface of the front wall of the front bowl-shaped body 1A and supports the fixed end of the return spring 4 is fixed to the tie rod 14, and A retaining ring 25 facing the outer surface of the front wall of the body 1A is removably locked to the tie rod 14, and an annular recess 26 for receiving the retaining ring 25 is formed on the rear end surface of the mounting flange 8a. An assembly of a booster and a master cylinder, characterized in that: