JP2537332Y2 - Tandem brake 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 tandem brake booster, and more particularly, to a tandem brake booster having improved workability in assembling a valve body and a center body.

[0002]

2. Description of the Related Art A conventional tandem brake booster is
Generally, passage communicating between the front and rear of the constant-pressure chamber with a built-in valve mechanism for opening and closing control and between the variable pressure chamber and the atmosphere of the image made the constant pressure chamber and the variable pressure chamber within the shell is formed A valve body, a center body formed with a passage connectable to the passage of the valve body, and connected to the valve body, and dividing the inside of the shell into a constant-pressure chamber and a variable-pressure chamber, and connecting the central portion to each of the passages. The vehicle includes a front and rear power piston having a passage formed therein. Such tandem brake booster, each passageway of the valve body and the center Bode I have are continuous switches the passage and between the variable pressure chamber and the atmosphere constant pressure chamber and the variable pressure chamber by the switching of the valve mechanism This allows each power piston to reciprocate in the shell to brake or release the vehicle.

[0003]

However, in the conventional tandem brake booster, when assembling the valve body and the center body, it is necessary to surely communicate a vacuum passage connecting the two constant pressure chambers. some reason, not communicated by aligning the respective passages while rotating these two bodies to each other not, the assembling property is not always good.

[0004] The present invention has been made to solve the above problems, thereby reliably communicated with respective passages only by simply overlapping the valve body and the center body, before
It is an object of the present invention to provide a tandem-type brake booster that can form a vacuum passage communicating between the constant pressure chambers later and has excellent assembling workability.

[0005]

Means for Solving the Problems A tandem type according to the present invention.
The brake booster is a section that partitions the inside of the closed shell
Into the room before and after the center plate and the center plate.
It is arranged to be able to retreat, and each chamber is connected to the constant pressure chamber on the front side.
A front diaphragm and a rear
And the rear diaphragm and the valve body
Open / close control between constant pressure chamber and transformer chamber and between transformer chamber and atmosphere
A valve mechanism connected to the valve body and the center
A center that slides on the center of the plate via a sealing member
-The two constant-pressure chambers are formed in a valve body.
The passage formed and the valve formed in the center body
Connected via a passage that can communicate with the passage of the body
In particular, there is a valve body inside the center body.
At the part where the body and the center body oppose each other in the axial direction,
An annular groove and a radial groove continuous with the annular groove are provided.
The valve body passage and the center body are
And the constant pressure chamber on the rear side.
The passage of the center body communicating with the
It is an opening between the rear end face and the rear power piston .

[0006]

According to the present invention, when the valve body and the center body of the tandem type brake booster are connected to each other at an arbitrary position when the valve body and the center body are connected, the annular groove is continuous with the annular groove. The passage of the valve body and the passage of the center body can be communicated with each other via the radial groove.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. FIG. 1 is a view showing an entire embodiment of a tandem brake booster according to the present invention. A front power piston 4, a rear power piston 5 and a front power piston 4 are provided in a closed shell 3 constituted by a front shell 1 and a rear shell 2. Are arranged in series. The inside of the closed shell 3 is divided into a front chamber on the side of the front power piston 4 and a rear chamber on the side of the rear power piston 5 by a center plate 6, and the front chamber is a front diaphragm attached to the back of the front power piston 4. 7 , always communicates with the negative pressure source
A constant pressure chamber A and a transformation chamber B into which air is introduced during operation .
The rear chamber is always connected to a negative pressure source by a rear diaphragm 8 attached to the rear of the rear power piston 5.
A constant-pressure chamber C and a variable-pressure chamber D into which the atmosphere is introduced during operation .

Reference numeral 9 denotes a substantially funnel-shaped valve body disposed at the axial center of the closed shell 3, and a cylindrical portion 9A having a valve mechanism 10 described later therein and a cylindrical portion 9A which are sequentially expanded integrally. It has a cylindrical middle diameter portion 9B and a large diameter portion 9C which are continuously provided with a diameter. The center body 11 is fitted at the rear end of the large diameter portion 9C, and each of the rear piston 5 and the rear diaphragm 8 is inserted into an annular groove formed in the valve body 9 on the rear side of the fitted portion. The periphery is fitted. Further, the inner peripheral portions of the front power piston 4 and the front diaphragm 7 attached to the rear surface thereof extend along the inner peripheral surface of the center body 11, and these inner peripheral portions correspond to the large-diameter portion 9C of the valve body 9. And the center body 11. A plurality of projections 7A are formed on the outer peripheral surface of the front diaphragm 7 sandwiched between the large diameter portion 9C of the valve body 9 and the center body 11, and the inner peripheral surface of the center body 11 is formed by these projections 7A. , A gap is formed between the two 7 and 11, and this gap will be described later.
A passage connecting the front and rear transformer chambers B and D is formed. The center plate 6 has an inner peripheral portion that is slidable in the axial direction in the center body 11 via a seal member 12.

An operating rod 13 interlocked with a brake pedal (not shown) is provided in a center hole of the valve body 9.
A valve plunger 14 caulked to the spherical end portion 13A of the valve body 9 is slidably fitted. On the other hand, a driven rod 16 is connected to a front end of a center hole of the valve body 9 via a reaction disk 15. Has been established. Therefore, when the tandem brake booster is operated, the brake reaction force is transmitted to the brake pedal via the driven rod 16, the reaction disk 15, the valve plunger 14, and the operating rod 13. Reference numeral 17 denotes a key inserted through a radial key groove 9D formed at the rear end of the middle diameter portion 9B of the valve body 9 to prevent the valve plunger 14 from coming off. Also, 1
Reference numeral 8 denotes a return spring mounted between the inner surface of the front shell 1 and a retainer 19 fitted to the rear end of the driven rod 16, and constantly biases the front power piston 4 and the rear power piston 5 toward the inoperative position side in the drawing. doing.

The valve body 9 has a passage 20 axially penetrating the side wall at a position adjacent to the center hole.
A constant pressure chamber A on the front side communicates with the inside of the cylindrical portion 9A through the passage 20. In addition, the rear side of the middle diameter portion 9B of the valve body 9 has a rear side pressure change.
A passage 21 connecting the chamber D and the cylindrical portion 9A is formed in the radial direction, and the passage 21 and the passage 20 are connected to each other on the front side.
Can be communicated with the constant-pressure chamber A and the rear-side transformer chamber D. A projection 11E is formed on the rear end face of the center body 11 so as to penetrate the inner peripheral portions of the rear power piston 5 and the rear diaphragm 8, and an axial through hole is formed in the projection 11E. This hole forms a passage 22 that is continuous with a gap formed by the front diaphragm 7 and the inner surface of the center body 11.
The transformer chamber B on the front side and the transformer chamber D on the rear side communicate with each other via the second side .

The rear end surface of the large-diameter portion 9C of the valve body 9 and the inner surface of the overhang portion 11A formed at the rear end of the center body 11 abutting on the large-diameter portion 9C are formed as follows.

As shown in FIG. 2, a plurality of radial grooves 9F are provided on the rear end face of the large diameter portion 9C of the valve body 9 at equal intervals in the circumferential direction. A wide passage 23 is formed in each direction. On the other hand, as shown in FIG. 3, the inner surface of the overhang portion 11A of the center body 11 which abuts on the abutment surface 9G at the rear end has an annular groove 11C in the middle of the width direction and the annular groove 11C. A passage 24 that penetrates 11A in the axial direction is formed. Accordingly, when the center body 11 is assembled to the valve body 9, the contact surface 9G of the valve body 9 and the contact surface 11D of the projecting portion 11A of the center body 11 are in contact with the passage 23 of the valve body 9 and the center. The passage 24 of the body 11 is continuous via the radial groove 9F and the annular groove 11C, and the front side constant pressure chamber A and the rear side constant pressure chamber A are connected.
And a chamber C you communicating.

Therefore, according to this embodiment, the tandem type
When assembling the rake booster, the passage 23 of the valve body 9 and the passage 24 of the center body 11 communicate with each other.
Between the front side constant pressure chamber A and the rear side constant pressure chamber C
In the case of forming an air passage , simply by superimposing the two 9 and 10, the radial groove 9 of the valve body 9 is formed.
F and the two passages 23, 24 can be communicated through the annular groove 11C of the center body 11, and both the passages 23, 24 are rotated while rotating the bodies 9, 11 as in the conventional case.
There is no need to position the 24, and the assembling work can be easily performed.

FIG. 4 is a view showing another embodiment of the tandem type brake booster of the present invention. In this embodiment, FIG.
In the above embodiment, the rear end face of the large-diameter portion 9C of the valve body 9 is made flat without grooves, while the projecting portion 11A of the center body 11 is provided with a halfway extending from the annular groove 11C to the inner surface.
A plurality of radial grooves 11E are provided at equal intervals in the circumferential direction.
Otherwise, the configuration is the same as in the above embodiment. In this embodiment as well, the same functions and effects can be expected as in the above embodiment.

The tandem-type brake booster of the present invention is not limited to the above-described embodiments, but includes an annular groove continuous with each of these passages at a position where the valve body and the center body are opposed to each other. If the groove is provided with a continuous radial groove, they are all included in the present invention.

[0016]

[Effects of the Invention] As described above, according to the present invention, the passages can be surely communicated simply by overlapping the valve body and the center body, and the tandem-type brake is excellent in assembling workability. A force device can be provided. In addition, a cell that communicates with the constant pressure chamber on the rear side
The passage of the center body, the rear end of the center body and the rear
Boosted by opening between power piston
The axial length of the entire device can be reduced .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an entire tandem brake booster according to an embodiment of the present invention.

FIG. 2 is an enlarged partial perspective view showing a main part of a valve body of the tandem brake booster shown in FIG.

FIG. 3 is an enlarged partial perspective view showing a main part of a center body abutting on a rear end surface of the valve body shown in FIG. 2;

FIG. 4 is a view corresponding to FIG. 2 showing a center body of another embodiment of the tandem brake booster of the present invention.

[Explanation of symbols]

 1 Shell 4 Front Power Piston 5 Rear Power Piston 9 Valve Body 9F Groove 11 Center Body 11C Annular Groove 23 Passage 24 Passage 11E Groove A to D Pressure Chamber

Claims (1)

(57) [Scope of request for utility model registration] 1. A center for partitioning the inside of a closed shell back and forth.
Moveable into and out of the room around the plate and center plate
Each room is divided into a constant pressure room and a transformer room.
Front and rear diaphragms,
Built in the valve body, between the constant pressure chamber and the
A valve mechanism that controls opening and closing between the transformer chamber and the atmosphere;
And the center of the center plate is sealed.
A center body that slides through the
Both constant pressure chambers are connected to the passage formed in the valve body and the center.
Formed on the body and can communicate with the valve body passage
Such in tandem brake booster which is connected via a passage, at a portion where the valve body and the centers body inside the center body axially opposite to the annular groove and the annular groove
Provide continuous radial grooves, and through these grooves
Make the valve body passage and the center body passage communicate with each other.
And a center body that communicates with the constant pressure chamber on the rear side
Passageway of rear end face of center body and rear power fixer
A tandem brake booster characterized by having an opening between it and