JPH09202229A - Negative pressure booster with check-valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost by using a grommet without special seal means for a seal of a split housing of a check-valve attached to a booster shell of a negative pressure booster through the grommet. SOLUTION: A housing 13 of a check-valve 6 is made to be constituted of a housing body 15 and lid body 16 fitting into the housing body 15. An annular first and second seal lips 37, 38 close to these external surfaces are formed in a grommet 12, and an outer end edge 39 of the fitting surface of the housing body 15 and the lid body 16 between both seal lips 37, 38 is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve having a negative pressure outlet port communicating with a negative pressure chamber and a negative pressure inlet port communicating with a negative pressure source in a mounting hole formed in a booster shell. The present invention relates to a negative pressure booster with a check valve, which comprises a housing main body and a lid, which are attached to each other via a grommet, and which are axially fitted and coupled to each other.

[0002]

2. Description of the Related Art Such a negative pressure booster with a check valve is disclosed, for example, in Japanese Utility Model Publication No. 2-30381.
Already known.

[0003]

In the check valve in the conventional negative pressure booster with a check valve, a special sealing means such as adhesion or welding is provided between the fitting surfaces of the housing body and the lid constituting the housing. This is one of the obstacles to cost reduction.

Therefore, in the present invention, the sealing between the fitting surfaces of the housing main body and the lid can be performed by using the grommet between the housing and the booster shell, and special sealing means such as adhesion and welding is provided. An object is to provide an inexpensive negative pressure booster with a check valve that is unnecessary.

[0005]

In order to achieve the above object, the present invention provides at least a pair of grommets which are in close contact with the outer surface of a housing with an outer end edge of a mating surface of a housing body and a lid body sandwiched therebetween. It is characterized in that a seal lip of is formed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments of the present invention shown in the accompanying drawings.

First, in FIG. 1, reference numeral B is a negative pressure booster for a vehicle brake, and the interior of the booster shell 1 is partitioned by a diaphragm 2 into a negative pressure chamber 3 on the front side and a working chamber 4 on the rear side. The negative pressure chamber 3 includes a negative pressure conduit 5 and a check valve 6 inside an intake manifold V of the engine, which is a negative pressure source.
Is communicated through.

The booster piston 7 connected to the diaphragm 2 is connected to an input rod 8 supported on the rear wall of the booster shell 1 via a control valve (not shown), and is attached to the front wall of the booster shell 1. It is also connected to the piston of the brake master cylinder 9. Thus, when the input rod 8 is at rest, the control valve controls the working chamber 4 to the same pressure as the negative pressure chamber 3 so that the booster piston 7 is returned to the retracted position, but the brake pedal 10 is depressed. When the input rod 8 is moved forward, atmospheric pressure is introduced into the working chamber 4 by switching the control valve, and the booster piston 7 moves forward due to the pressure difference between the working chamber 4 and the negative pressure chamber 3 to cause the brake master cylinder to move forward. 9 is boosted.

As shown in FIGS. 2 and 3, the check valve 6 is
Is attached to a mounting hole 11 formed in the front wall of the booster shell 1 via a grommet 12 made of an elastic material such as rubber.

The housing 13 of the check valve 6 is made of synthetic resin and has a cylindrical housing body 1 having a valve chamber 14 inside.
5 and a lid 16 which is also made of synthetic resin and closes the open end of the valve chamber 14. An annular locking groove 17 is formed on the inner peripheral surface of the open end of the housing body 15,
The housing main body 15 and the lid body 16 are joined by engaging the annular locking claw 18 formed on the outer periphery of the fitting portion 16a of the lid body 16 fitted to the inner peripheral surface with the locking groove 17. It

The housing body 15 has a negative pressure outlet port 19 for communicating the valve chamber 14 with the negative pressure chamber 3 and a valve seat 20 surrounding the negative pressure outlet port 19, and a poppet type valve body 21 cooperating with the valve seat 20. A valve spring 22 for biasing the valve spring 20 in the seating direction with the valve seat 20 is housed in the valve chamber 14. Umbrella part 2 of valve body 21
A rubber valve plate 21c that can be in close contact with the valve seat 20 is attached to the la 1a.

The lid 16 has a connecting pipe 24 which projects outward as a negative pressure inlet port 23 which communicates with the valve chamber 14 inside.
A guide boss 25 projecting from the center of the negative pressure inlet port 23 toward the valve chamber 14 is formed.
It is integrally connected to the inner peripheral wall of the negative pressure inlet port 23 via a plurality of ribs 26. With this guide boss 25, the valve body 2
One valve rod 21b is slidably supported. Connection pipe 2
The downstream end of the negative pressure conduit 5 is fitted into and connected to 4.

Further, a plurality of annular locking claws 27 arranged in a sawtooth shape are provided on the outer periphery of the front half of the housing body 15.
Further, small flanges 28 are formed at the base ends thereof, respectively.

A small flange 28 and a large flange 29 are integrally formed at opposite ends of the housing body 15 and the lid body 16, and the small flange 28 is fitted in the annular recess 30 of the large flange 29. The large flange 29 integrally has a short cylindrical portion 31 on its outer circumference, and the large flange 29 with the cylindrical portion 21 defines an annular engagement groove 33 between the large flange 29 and the outer peripheral surface of the housing body 15. .

On the other hand, the grommet 12 has a ring shape, and the mounting hole 1 of the booster shell 1 is provided on the outer periphery thereof.
It has a pair of first and second annular protrusions 35 and 36 that define an annular mounting groove 34 with which one peripheral edge fits. The outer peripheral surface of the first annular projection 35 arranged in the booster shell 1 is a tapered surface. Further, the outer peripheral surface of the second annular protrusion 36 arranged outside the booster shell 1 is a cylindrical surface, and as clearly shown in FIG. 4, the outer peripheral surface and the inner peripheral surface of the grommet 12 have a cylindrical portion 31. The outer and inner seal lips 37 and 38, which are in close contact with the inner peripheral surface of the housing and the outer peripheral surface of the housing body 15, are integrally formed. Therefore, the both seal lips 37, 38 are arranged so as to sandwich the outer end edge 39 of the fitting surface of the housing body 15 and the lid body 16 therebetween.

Next, the operation of this embodiment will be described.

When mounting the check valve 6 on the booster shell 1, first, the grommet 12 is strongly inserted into the mounting hole 11 of the booster shell 1 with the first annular projection 35 thereof at the head. Then, the peripheral edge of the mounting hole 11 of the booster shell 1 is fitted into the mounting groove 34 of the grommet 12, and the annular projections 35 and 36 of the grommet 12 tightly clamp the front wall of the booster shell 1 from inside and outside.

Next, the housing 13 of the check valve 6 is strongly inserted into the center hole of the grommet 12 with the housing body 15 at the top. Then, the annular locking claw 27 of the housing body 15 bites into the inner peripheral surface of the center hole of the grommet 12, and thus the housing 13 is tightly supported by the grommet 12.

At this time, the second annular projection 3 of the grommet 12
6 is fitted in an annular engagement groove 33 between the housing body 15 and the lid body 16, and the inner and outer seal lips 37 and 38 of the grommet 12 are the outer peripheral surface of the housing body 15 and the cylindrical portion of the lid body 16. The outer peripheral edge 39 of the fitting surface of the housing body 15 and the lid 16 is sandwiched between the inner peripheral surface 31 and the inner peripheral surface 31. Therefore, the housing body 15
The grommet 12 can seal between the fitting surfaces of the lid body 16 without providing a special sealing means between the fitting surfaces.

When using the negative pressure booster B, if the negative pressure inlet port 23 of the check valve 3 is connected to the intake manifold V of the engine through the negative pressure conduit 5 and the engine is operated, the intake manifold V The negative pressure generated in the negative pressure conduit 5
Through the negative pressure inlet port 23 to the valve chamber 14 to separate the valve body 21 from the valve seat 20 against the set load of the valve spring 22 to open the valve. Therefore, the negative pressure is transmitted from the valve chamber 14 to the negative pressure chamber 3 of the booster shell 1 via the negative pressure outlet port 19, and is stored in the chamber.

When the negative pressure in the intake manifold V decreases or disappears due to the stop of the operation of the engine, the valve body 21 has the set load of the valve spring 22 and the valve seat 2
Since the valve is seated at 0 and closed, it is possible to prevent the reverse flow of negative pressure from the negative pressure chamber 3 to the intake manifold V side.

FIG. 5 shows another embodiment of the present invention.
Inner and outer seal lips 27, 28 of the grommet 12
Except for the difference in the shape of, it has the same configuration as the previous embodiment,
In the figure, parts corresponding to those in the previous embodiment are denoted by the same reference numerals.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the gist. For example, the inner and outer seal lips 37, 38 may be formed on the axial end faces of the grommet 12. In addition, outer and inner seal lips 37, 3
It is also possible to provide a plurality of 8 items.

[0024]

As described above, according to the present invention, at least a pair of seal lips that are in close contact with the outer surface of the housing are formed on the grommet with the outer end edges of the fitting surfaces of the housing body and the lid being sandwiched therebetween. Therefore, the sealing between the fitting surfaces of the housing main body and the lid can be performed by using the grommet that originally exists, and therefore it is necessary to provide a special sealing means such as adhesion or welding between the fitting surfaces. Can be eliminated, which can contribute to cost reduction.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of essential parts of a negative pressure booster with a check valve according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of part 2 in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a semi-longitudinal sectional view of a single unit of the grommet in FIG.

FIG. 5 is a semi-longitudinal sectional view of a single unit of the grommet showing another embodiment of the present invention.

[Explanation of symbols]

 B Negative pressure booster V Negative pressure source 1 Booster shell 3 Negative pressure chamber 6 Check valve 11 Mounting hole 12 Grommet 13 Housing 15 Housing body 16 Lid 19 Negative pressure outlet port 23 Negative pressure inlet port 37 Outer peripheral seal lip 38 Inner peripheral seal Lip 39 Outer edge of mating surface

Claims (1)

[Claims] 1. A negative hole communicating with a negative pressure outlet port (19) communicating with a negative pressure chamber (3) and a negative pressure source (V) in a mounting hole (11) formed in a booster shell (1). Check valve (6) housing (1) with pressure inlet port (23)
3) is attached via a grommet (12), and a negative pressure booster with a check valve, which comprises a housing body (15) and a lid body (16) to which the housing (13) is axially fitted and coupled with each other. In the grommet (12), at least a pair of seal lips () that are in close contact with the outer surface of the housing (13) with the outer end edge (39) of the fitting surface of the housing body (15) and the lid body (16) interposed therebetween. 37, 38) is formed,
Negative pressure booster with check valve.