JP2534087Y2 - Booster - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster, and more particularly, to a coupling structure of a valve body provided in a cylindrical portion of a valve body.

[0002]

2. Description of the Related Art Conventionally, as a booster, a tubular portion slidably provided in a shell and formed on the rear side is projected outside the shell through an opening provided on the rear side of the shell. A valve body, a bearing provided at the opening of the shell and slidably supporting an outer peripheral surface of the cylindrical portion of the valve body; and an inner periphery of the cylindrical portion located within a sliding range with the bearing. a stepped portion which bulges radially inwardly provided in section, is formed in the schematic tubular that example Bei and a valve body provided in the cylindrical portion of the valve body is known. So
The valve body is made of synthetic resin,
It is provided on the inner peripheral portion of the cylindrical portion on the front side of the step
Bulges inward in the radial direction, and the seat of the valve body is seated.
A first valve seat, which is opened on the outer peripheral side of the first valve seat, and is fixed.
A constant pressure passage communicating with the pressure chamber is integrally provided.
The rear end of the valve body is a step provided on the cylindrical portion.
And the retainer are pinched and connected to the step of the cylindrical part.
You.

[0003]

In the above-described conventional booster, the valve body is manufactured by pouring a molten synthetic resin into a mold. At this time, the valve body is integrated with the inner peripheral surface of the cylindrical portion. The step is formed at the end of the step. The rear end of the valve body is pinched and connected by the step of the cylindrical portion and the retainer. However, if the step is integrally formed on the inner peripheral surface of the cylindrical portion as described above, the thickness of the cylindrical portion differs before and after the step. Therefore, when the synthetic resin poured into the mold is solidified, the outer peripheral surface of the cylindrical portion at the position where the step is provided is slightly reduced in diameter, resulting in the occurrence of irregularities in that portion. When the outer peripheral surface of the cylindrical portion of the valve body becomes uneven as described above, smooth sliding between the outer peripheral surface of the cylindrical portion and the bearing is impeded.

[0004]

[Means for Solving the Problems] In view of such circumstances,
According to the present invention, there is provided a valve body slidably provided in a shell and having a cylindrical portion formed on a rear side protruding outside the shell through an opening provided on a rear side of the shell; A bearing slidably supporting the outer peripheral surface of the cylindrical portion of the valve body; and a radially extending inner portion of the cylindrical portion located within a sliding range with the bearing. And a valve body formed in a substantially cylindrical shape and provided in the cylindrical portion of the valve body.
For example, the valve body is made from synthetic resin, the
It is provided on the inner peripheral portion of the cylindrical portion on the front side of the step
Bulges inward in the radial direction, and the seat of the valve body is seated.
A first valve seat, which is opened on the outer peripheral side of the first valve seat, and is fixed.
And a constant pressure passage communicated with the pressure chamber together, further the end portion of the rear side of the upper Kibentai sandwiches connected to the step portion of the cylindrical portion by the step portion and a retainer provided on the tubular portion times In the force device, the thickness of the cylindrical portion of the valve body is made substantially the same over at least a sliding range with the bearing, and the cylindrical member is fitted into the cylindrical portion of the valve body. The rear end of the tubular member is the stepped portion. Further, according to the present invention, in the booster described above, the thickness of the cylindrical portion of the valve body is made substantially the same at least over a sliding range with the bearing,
Further, a plurality of ribs extending toward the rear side in the axial direction are formed on the inner peripheral surface of the tubular portion of the valve body, and the ends of the plurality of ribs on the rear side are the step portions.

[0005]

According to such a construction, the thickness of the cylindrical portion of the valve body, which is in the sliding range with the bearing, is substantially the same. No irregularities are formed on the outer peripheral surface of the shape portion. Therefore, smooth sliding between the cylindrical portion of the valve body and the bearing is not hindered.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, a substantially cylindrical valve body 2 is slidably provided in a shell 1 of a brake booster. The power piston 3 is connected. A diaphragm 4 is stretched on the back of the power piston 3, and the diaphragm 4 partitions the inside of the shell 1 into a constant pressure chamber A on the front side and a variable pressure chamber B on the rear side. On the rear side of the valve body 2, there is formed a cylindrical portion 2a extending toward the rear side in the axial direction.
a protrudes outward from the shell 1 from an opening 1 a provided on the rear side of the shell 1. An annular bearing 5 is provided in the opening 1 a of the shell 1, and the bearing 5 slidably supports the outer peripheral surface of the cylindrical portion 2 a of the valve body 2. A cylindrical portion 2a of the valve body 2 is provided at a position adjacent to the bearing 5 in the opening 1a of the shell 1.
Annular sealing member 6 for maintaining airtightness between the opening 1a
The inner peripheral portion of the seal member 6 is brought into sliding contact with the outer peripheral surface of the cylindrical portion 2a. A valve mechanism 7 having a conventionally known configuration is provided in the cylindrical portion 2a of the valve body 2, and the constant pressure chamber A and the variable pressure chamber B are provided by the valve mechanism 7.
The fluid circuit between them is switched. That is, the valve mechanism 7 includes an annular first valve seat 8 formed in the cylindrical portion 2 a of the valve body 2 and the annular first valve seat 8.
An annular second valve seat 10 formed at the right end of a valve plunger 9 slidably provided on the valve body 2 inside the valve body 2, and further, both valve seats 8, 10 are seated on the right side of FIG. And a valve body 12 to be used. The valve body 12 is formed in a substantially cylindrical shape by rubber, and has an annular end face directed radially at a front end thereof, and an outer peripheral side of the end face is seated on the first valve seat 8. 1st seat part 12
a, and the inner peripheral side of the end face is the second valve seat 10.
The second seat portion 12b is seated on the vehicle. Further, the rear end 12c of the valve body 12 is set to have an outer diameter larger than that of the front end where the seat portions 12a and 12b are formed, and to be thick. And
The rear end 12c of the valve body 12 is
Is fitted to the center of the inner peripheral surface of the cylindrical portion 2a and is held by the retainer 13. One end of a spring 14 provided between the retainer 13 and an input shaft, which will be described later, is pressed against the retainer 13, thereby urging the retainer 13 toward the front side. The central portion in the axial direction of the valve body 12 is a curved portion that is easily deformed, so that the seat portions 12a and 12b can be brought into contact with and separated from the valve seats 8 and 10. The space on the outer peripheral side of the contact portion between the first valve seat 8 and the first seat portion 12a of the valve body 12 is formed through a constant pressure passage 18 formed in the valve body 2 in the axial direction.
Is communicated to. In the constant pressure chamber A, a negative pressure is introduced from a negative pressure source via a negative pressure introducing pipe (not shown) connected to a wall surface on the front side of the shell 1. On the other hand, the first
On the inner peripheral side of the contact portion between the valve seat 8 and the first seat portion 12a of the valve body 12, the second seat portion 1 of the second valve seat 10 and the valve body 12 is provided.
The space that is on the outer peripheral side of the contact portion with the portion 2b is communicated with the variable pressure chamber B via a radial variable pressure passage 19 formed in the valve body 2. Further, a space on the inner peripheral side of the contact portion between the second valve seat 10 and the second seat portion 12b of the valve body 12 is provided with a pressure passage 20 formed by the inner peripheral surface of the cylindrical portion 2a of the valve body 2. It is communicated with the atmosphere via a filter 21 provided there. The right end of the valve plunger 9 slidably provided on the valve body 2 is connected to an input shaft 22 interlocked with a brake pedal (not shown), and the left end of the valve plunger 9 is It faces the right end surface of the reaction disk 24 housed in the inside 23a. And the above push rod 23
Is linked to a master cylinder piston (not shown). Since the valve body 2 is urged toward the rear side by the return spring 25, the key member 26 engaged with the valve plunger 9 normally comes into contact with the rear side wall surface 1b of the shell 1 in the inoperative position shown in the drawing. Is held in. As shown in an enlarged manner in FIG. 2, in this non-operating state, the second seat portion 12b of the valve body 12 is seated on the second valve seat 10, but the first seat portion 12a of the valve body 12
A slight gap is maintained between the first valve seat 8 and the first valve seat 8. Therefore, a negative pressure is introduced not only into the constant pressure chamber A but also into the variable pressure chamber B. The above configuration and the operation based on it are the same as those of the conventionally known brake booster.

In this embodiment, the valve body 2
A step portion is formed on the front side of the inner peripheral portion of the cylindrical portion 2a, and an annular groove 2b is formed on the end surface of the step portion. The distal end of an annular projection formed on the inner peripheral side of the annular groove 2b is the first valve seat 8. In this embodiment,
The thickness of the cylindrical portion 2a on the rear side from the position where the annular groove 2b is provided is set to be the same, and the outer peripheral surface of the cylindrical portion 2a having the same thickness slides on the bearing 5. I am trying to do it. Further, as shown in FIG. 3, the constant pressure passage 18 is constituted by an axial hole drilled from the bottom of the annular groove 2b toward the front side in the axial direction. Two axial holes are drilled as 18. In the present embodiment, the valve element 12
Is connected to the inside of the tubular portion 2a of the valve body 2 as follows. That is, the tubular member 29 is fitted to the inner peripheral surface of the tubular portion 2a from the rear side, and the front end of the tubular member 29 is brought into contact with the bottom of the annular groove 2b. A step is formed by the rear end of the tubular member 29 fitted in the tubular portion 2a as described above,
The rear end 12c of the valve body 12 is axially held by the rear end of the tubular member 29 as the stepped portion and the retainer 13 described above, and also falls radially inward. Hold on not to.

[0008] According to the present embodiment configured as described above,
The following operation and effects can be obtained as compared with the related art in which the cylindrical portion 2a of the valve body 2 and the cylindrical member 29 fitted thereto are manufactured integrally with a synthetic resin. That is, in the conventional valve body 2, when the synthetic resin poured into the mold is solidified in manufacturing the valve body 2, the outer diameter of the cylindrical portion 2 a at the position of the step is reduced, and The unevenness is generated on the outer peripheral surface of the shape portion 2a. In this case, smooth sliding between the cylindrical portion 2a and the bearing 5 is impeded, and the cylindrical portion 2a
A gap is formed between the outer peripheral surface of the seal member and the inner peripheral portion of the seal member 6 slidably contacting the seal member, and the seal leaks from that portion. On the other hand, in the present embodiment, the valve body 2
The cylindrical portion 2a and the cylindrical member 29 fitted thereto are manufactured from separate members, and the rear end of the cylindrical member 29 forms a stepped portion. The plate thickness of the two cylindrical portions 2a can be set to be the same.
Therefore, when the valve body 2 is manufactured, the outer peripheral surface of the cylindrical portion 2a, which is the position of the step, is not reduced in diameter and irregularities are not generated. Therefore, smooth sliding between the bearing 5 and the outer peripheral surface of the cylindrical portion 2a is not hindered,
Further, the seal does not leak from between the seal member 6 and the outer peripheral surface of the cylindrical portion 2a. Further, in this embodiment, the radial dimension of the constant pressure passage 18 formed from the annular groove 2b of the valve body 2 toward the front side can be increased by the amount of the cylindrical member 29 provided as a separate member. As a result, a large flow passage area of the constant pressure passage 18 can be secured, and therefore, the return speed when the brake booster returns from the operating state to the non-operating state can be increased.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. In the second embodiment, the annular groove 102b is formed on the inner peripheral surface of the cylindrical portion 102a of the valve body 102. A linear rib 129 extending from the bottom to the rear side in the axial direction is formed. Then, the plurality of ribs 12
9, a rear end of the valve element 112 is axially sandwiched between the rear end of the rib 129 and the retainer 113, and the stepped portion is formed by a radius. It is held so that it does not fall in the direction. The other configuration is the same as that of the first embodiment. Each member corresponding to the member of the first embodiment has, in principle, 10 members.
The member number obtained by adding 0 is assigned. Even with such a configuration of the second embodiment, the same operation and effect as those of the first embodiment can be obtained.

FIG. 6 shows a third embodiment of the present invention. In the third embodiment, basically, the second
Assuming the configuration of the embodiment, an annular member 230 corresponding to the size of the rib 229 is brought into contact with the rear end of each rib 229, and the rear end surface of the annular member 230, the retainer 213, and the like. Thus, the rear end 212c of the valve element 212 is held. The other configuration is the same as that of the second embodiment, and the members corresponding to the members of the second embodiment are given the member numbers obtained by adding 100 in principle. Even with such a configuration of the third embodiment, the same operation and effect as those of the above-described embodiments can be obtained.

[0011]

As described above, according to the present invention, it is possible to obtain an effect that the smooth sliding between the cylindrical portion of the valve body and the bearing is not hindered.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a sectional view of a main part taken along line III-III in FIG. 2;

FIG. 4 is a sectional view showing a second embodiment of the present invention;

FIG. 5 is a sectional view of a main part taken along line VV of FIG. 4;

FIG. 6 is a sectional view showing a third embodiment of the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Shell 1a Shell opening 2 Valve body 2a, 102a, 20
2a cylindrical part 5 bearing 12, 112, 212
Valve body 12c, 112c, 212c Rear end portion of valve body 13, 113, 213 Retainer 29 Cylindrical member 129, 229 Rib A Constant pressure chamber B Variable pressure chamber 230 Ring member

Claims (3)

(57) [Scope of request for utility model registration] A valve body provided slidably in the shell and having a cylindrical portion formed on the rear side projected outside the shell through an opening provided on the rear side of the shell; A bearing provided at the opening to slidably support the outer peripheral surface of the cylindrical portion of the valve body; and a radial direction provided at an inner peripheral portion of the cylindrical portion located within a sliding range with the bearing. a stepped portion that bulges inward, is formed in a general cylindrical shape with a valve body <br/> Bei example provided in the cylindrical portion of the valve body, the valve body is made from synthetic resin, the Step
On the inner peripheral part of the cylindrical part on the front side
Bulges inward and the seat of the valve body is seated
A first valve seat, and a constant-pressure chamber which is opened on an outer peripheral side of the first valve seat.
Booster provided integrally, and the end portion of the rear side of the upper Kibentai sandwiched connected to the step portion of the cylindrical portion by the step portion and a retainer provided on the tubular portion further a constant pressure passage communicated with In the above, the thickness of the cylindrical portion of the valve body is made substantially the same at least over a sliding range with the bearing, and a cylindrical member is fitted into the cylindrical portion of the valve body, A booster wherein the rear end of the cylindrical member is the stepped portion. 2. A valve body provided slidably in the shell and having a cylindrical portion formed on the rear side projected outside the shell through an opening provided on the rear side of the shell, and an opening of the shell. A bearing slidably supporting the outer peripheral surface of the cylindrical portion of the valve body; and a radially extending inner portion of the cylindrical portion located within a sliding range with the bearing. A step portion that bulges toward the front, and a valve body that is formed in a substantially cylindrical shape and is provided in the cylindrical portion of the valve body, and a step in which a rear end of the valve body is provided in the cylindrical portion. In the booster pinched and connected to the step of the cylindrical portion by the portion and the retainer, the thickness of the cylindrical portion of the valve body is
A plurality of ribs extending substantially toward the rear side in the axial direction are formed on the inner peripheral surface of the cylindrical portion of the valve body, at least substantially over the sliding range with the bearing,
A booster, wherein the rear ends of the plurality of ribs are the stepped portions. 3. The booster according to claim 2, wherein an annular member is interposed between a rear end of the rib in the cylindrical portion and a rear end of the valve body.