JPS5921094Y2 - pneumatic booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pneumatic booster for increasing the strength of a shell.

A pneumatic booster includes a valve body that is located in the center of the booster body and is movable in the axial direction, and a valve body that is movable in the radial direction and is located in the center of the booster body in a housing that is composed of a front shell and a rear shell. The diaphragm is arranged around the valve body and extends radially outward along the piston plate to the housing peripheral wall, and cooperates with the valve body to divide the interior of the shell into two chambers. This booster is equipped with a mask cylinder attached to the front shell using bolts, and a tow board (a plate that separates the driver's seat and the engine compartment of the vehicle) attached using bolts provided on the rear shell. ) and was generally fixedly supported.

When the booster is attached by such means, the front shell and the rear shell themselves must act as strength members to support the force acting on the mask cylinder when the brake foot pedal is depressed.

However, both shells are insufficient in strength to support the acting force acting on the mask cylinder, and this causes a problem in that both shells are deformed, increasing the stroke loss of the booster.

One possible way to solve this problem is to increase the thickness of the front and rear shells to increase the strength of the shells themselves, but this only results in the inconvenience of increasing the weight of the booster itself. This is not desirable as it means using a lot of materials unnecessarily.

The present invention provides a pneumatic booster that can withstand the force acting on the mask cylinder with sufficient strength without particularly increasing the wall thickness of the shell, and solves the above-mentioned problems and eliminates damage caused by damage to components. The purpose is not to cause a decline in the functionality of the vacuum booster.

Specific examples will be explained below based on the drawings.

In the embodiment shown in FIG. 1, the housing 1 is formed from a front shell 2 and a rear shell 3.

A valve body 4 having a flange portion 4a extending radially from the cylinder portion is slidably held in the rear shell 3, and a piston plate 5 is attached to the outer periphery of the flange portion 4a of the valve body 4.

The piston plate 5 includes a diaphragm 6 disposed around the valve body 4 and extending radially outward from the flange portion 4a of the valve body 4 to the shell peripheral wall.
are glued and placed.

Here, the defining member 7 is composed of the flange portion 4a of the valve body 4, the piston plate 5, and the diaphragm 6.

Note that when the valve body 4 is manufactured in a cylindrical shape having a flange portion 4a, the piston plate 5 and the diaphragm 6 constitute a defining member.

The inner peripheral end 5a of the piston plate 5 and the inner peripheral end 6a of the diaphragm 6 are fitted into the cylinder body 4, and the outer peripheral end 6b of the diaphragm 6 is connected between the respective ends 2a and 3a of the front shell 2 and rear shell 3. and plates 8, so that the housing 1 is divided into two chambers A and B by the defining member 7.

The valve body 4 includes a valve mechanism 9 for performing a boost operation.

This valve mechanism 9 is held by a valve body 4,
It is actuated by an input rod 10 connected to and acted upon by a foot pedal (not shown).

The tip or front end of the output rod 11 extends forward through the side wall of the front shell 2 and is connected to a piston (not shown) of a mask cylinder attached to the front shell 2 .

The rear end of the output rod 11 is slidably attached to the valve body 4 via a disk 12.

The pneumatic booster having the above configuration is known per se.

The connecting rod 13 passes through the front shell 2, the valve body 4, and the rear shell 3, and extends from the front of the housing 1 toward the rear. Books provided.

This connecting rod 13 has a threaded portion 13a protruding outside the front shell 2 at its tip, and a washer 14 is disposed on the shoulder between the main body portion 13b and the threaded portion 13a. 2 and is fixed by welding.

Further, the flange (not shown) of the mask cylinder is applied to the threaded portion 13a, and the mask cylinder is fixed by screwing in a nut.

The connecting rod 13 has an internal threaded portion 13C at its tip on the rear shell side, and a washer 1 is provided inside the through hole portion 3b of the rear shell 3.
5, the washer 16 is brought into contact with the outside, and the through hole portion 3b is
The rear shell 3 is fixed to the connecting rod 13 by disposing a sealing member 17 on the inner circumferential surface of the connecting rod 13 and screwing the ports 1 to 18.

In this example, the bolts 19 provided on the rear shell 3 are used for attachment to the toe board, but one end of the connecting rod 13 is installed protruding from the rear shell 3 without providing a separate bolt 19. However, this protruding portion may be formed into a threaded portion similarly to the threaded portion 13a, and the attachment may be performed using this threaded portion.

An axial passage 20 is formed in the connecting rod 13, and the chamber A on the front shell side and the chamber B on the rear shell side are communicated through this passage 20.

A through hole 21 is provided at a location in the valve body 4 through which the connecting rod 13 passes through the valve body 4.
One side 22C of the flexible cylinder 22 is fixed to.

The cylindrical body 22 has a large diameter cylindrical portion 22a and a small diameter cylindrical portion 22a.
b is folded back and connected to form a U-shaped cross section, and the whole is annular.

One side 22C of this cylindrical body 22 is connected to the eyebrow 2 of the through hole 21 of the guide member 23 having a flange 23a at one end.
The flange 23a that abuts on 1a and the presser metal fitting 24
It is clamped and fixed between.

The cylindrical body 22 extends in the axial direction of the connecting rod 13 with the cylindrical part 22a on its outer periphery in contact with the inner peripheral surface of the guide member 23, and then is folded back to become a cylindrical part 22b.
A protruding portion 22 d protruding inward from the cylindrical portion 22 b is fitted and fixed to the connecting rod 13 , and a free end 22 e of the cylindrical portion 22 b is an open end 20 a of the passage 20 provided in the connecting rod 13 . It is installed with the lid closed.

By arranging the cylinder as described above, the valve body 4 can easily move in the axial direction of the connecting rod 13, and the chamber A on the front shell side and the chamber B on the rear shell side are They communicate with each other via passage 20 only when chamber A is at a higher pressure than chamber B, but conversely when chamber A is at a lower pressure than chamber B.
The free end 22 e of the cylinder 22 is the open end 20 a of the passage 20
Since it is blocked, there is no communication.

That is, the free end 22e of the cylinder 22 functions as a check valve.

The guide member 23 is a cylindrical body made of a rigid body, and when the cylindrical portion 22 a of the cylindrical body 22 is brought into contact with the inner peripheral surface of the guide member 23 and the valve body 4 of the pneumatic booster is pushed in by the input rod 10, This prevents the cylindrical body 22 from expanding in the radial direction of the connecting rod 13 due to the pressure difference between the chambers A and B.
2a in the axial direction of the connecting rod 13.

In the example of FIG. 2, the check valve is formed by a ball 25.

A ball 25 is brought into contact with a shoulder 20b of the passage 20, and a spring 26 presses the ball 25 against the shoulder 20b.

As a result, the pressure in chamber A becomes higher than the pressure in chamber B,
When the ball 25 is pushed apart against the force of the spring 26, both chambers A
, B communicate, but remain closed under opposite pressure conditions.

In this example, the check valve is provided in the passage, which is advantageous in terms of space.

The other configurations are the same as in the previous example.

In each of the above sides, the connecting rod 13 passes through the valve body 4 as the defining member 7, but the same effect can be obtained even if it is formed to penetrate through the piston plate 5 and the diaphragm 6 as the defining member 7. play.

When the pneumatic booster configured as described above is attached to the vehicle body, the room A is pressed before the foot pedal is depressed.
and B are atmospheric pressure.

Then, by depressing the foot pedal, input lot 1 is input.
0, the movement is transmitted to the valve body 4, which moves along the connecting rod 13 in its axial direction.

When the valve body 4 moves to a certain point, the chamber A is vacuumed by the action of the valve mechanism 9, but since the chamber B is at atmospheric pressure, the output lot 11 is boosted and outputted.

1~ When the pedal is depressed slowly, the booster works as described above and there is no particular problem, but
If the foot pedal is suddenly depressed when the chamber A is at atmospheric pressure, a phenomenon occurs in which the chamber A is suddenly compressed, and the diaphragm 6, which is the defining member, expands abnormally.
This may cause parts to get caught, causing damage to the diaphragm, etc.

However, in the present invention, the high pressure in the chamber A is discharged to the chamber B by the passage 20 provided in the connecting rod 13 and the check valve.
No abnormal phenomenon as described above occurs.

Further, if configured as in the embodiment, when the valve body moves in the axial direction along the connecting rod, there is no sliding seal member interposed between the valve body or the defining member and the connecting rod. , due to wear caused by sliding, etc.
No seal leakage occurs in sliding parts.

Further, since the sealing cylinder is surrounded by the guide member, the cylinder does not expand in the radial direction of the connecting rod when the booster is activated, and no damage occurs due to expansion.

Furthermore, since the front shell and the rear shell are connected by a connecting rod, deformation of the shell can be prevented and reliability in durability is increased.

In addition, since almost no force is applied to the front and rear shells themselves, the shells can be made thinner than previous shells, or the shell material can be made of synthetic resin that is easy to mold without using metal. This greatly reduces the manufacturing cost of the booster.

In addition to the above examples, a seal is provided in which a sealing member is disposed on the defining member at a portion where the connecting rod penetrates the defining member, and the sealing member slides on the surface of the connecting rod when the booster is operated. The member can also be used in place of the cylinder.

As described above, since the pneumatic booster of the present invention is provided with a connecting rod that connects both shells, deformation of the shell can be prevented, and the shell can be made thin, making it easy to mold. Even if the shell can be formed from a synthetic resin and is formed from such a viewpoint, it will allow gas to flow from the front shell side chamber to the rear shell side chamber, but it will not allow gas to flow in the opposite direction. Since the check valve is installed to shut off the air pressure, the increase in the air pressure in the chamber on the front shell side due to sudden depression of the foot pedal can be suppressed to a predetermined value. In addition to being able to preferably solve the technical problems associated with the above, it is also possible to prevent abnormal expansion of the diaphragm of the defining member, to eliminate the diaphragm from getting caught in other parts, and to prevent damage to the diaphragm, etc. A unique technical problem can be solved in pneumatic boosters consisting of a defining member with a diaphragm, such as the present invention.

Furthermore, in the pneumatic booster of the present invention, since the above-mentioned check valve is provided in the passage provided in the connecting rod,
The connecting rod can be used for two functions, so that the check valve can be formed with fewer parts, which can improve manufacturability and significantly reduce manufacturing costs.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing a specific example of the pneumatic booster of the present invention, with the upper half showing a vertical cross section and the lower half showing a horizontal cross section, respectively. DESCRIPTION OF SYMBOLS 1...Casing, 2...Front shell, 3...Rear shell, 4...Valve body 17...National prestige member, 13...Connecting rod, 20...Passage, 22... Flexible cylinder.

Claims (2)

[Scope of utility model registration request] (1) A front shell, a rear shell combined with the front shell to form a housing, a valve body slidably held by the rear shell and having a valve mechanism inside, and a valve body that cooperates with the valve body. a defining member having a diaphragm that defines the inside of the shell into two chambers; and a connecting rod that airtightly penetrates both shells and the defining member, extends back and forth, and connects the two shells by both ends. In the pneumatic booster, the connecting rod is provided with a passage that communicates the two chambers, and the passage allows gas to flow from the chamber on the front shell side to the chamber on the rear shell side, and vice versa. A pneumatic booster characterized by being equipped with a check valve that shuts off the flow of water. (2) Attach one side of the annular flexible cylinder to the defining member and the other side to the connecting rod, and allow the connecting rod to pass through the penetrating portion of the defining member in an airtight manner, The pneumatic booster according to claim 1, wherein the other cylindrical portion of the annular flexible cylindrical body opens and closes the opening end of the passage.