JPH0353960Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a reaction disk for a brake booster, and more specifically to a reaction disk in which a reaction disk body and a back-up spring are vulcanized and bonded.

``Prior Art'' In general, a reaction disk of a brake booster includes a reaction disk body that is interposed between a valve plunger and a push rod and transmits the brake reaction force applied to the push rod to the valve plunger, and the reaction disk body. A back-up spring is integrally vulcanized and bonded to the valve body to prevent the reaction disk body from being caught between the valve body and the push rod.

The conventional back-up spring has a rectangular cross-sectional shape, and is placed at a desired position in the mold so that the longitudinal direction of the rectangle is in the radial direction of the reaction disk body. At the same time, the reaction disk body is vulcanized and bonded to the back-up spring at the same time as the reaction disk body is formed by vulcanizing a material such as rubber inside the chamber.

``Problem that the invention aims to solve'' However, during the above-mentioned vulcanization molding, the material filled in the mold gets wrapped around between the mold and the back-up spring, causing part of the back-up spring to become a reaction disc. The back-up spring may be buried inside the main body, or a part of the back-up spring may become twisted and deformed, resulting in a high incidence of defective products.

In order to improve this drawback, the above-mentioned back-up spring can be manufactured as a thin back-up plate instead of a ring, but in that case, due to the difference in the materials between the reaction disk body and the back-up spring, Warping may occur,
Further, there are drawbacks such as poor brake feeling, such as the tendency for jumping characteristics to fluctuate greatly at low temperatures.

``Means for Solving the Problems'' In view of such circumstances, the present invention provides a reaction disk body which is interposed between a valve plunger and a push rod and transmits the brake reaction force applied to the push rod to the valve plunger, and the rear A reaction disk for a brake booster equipped with a back-up spring that is integrally vulcanized and bonded to the front disk body to prevent the reaction disk body from being caught between the valve body and the push rod or valve plunger, The cross-section of the back-up spring is formed into a substantially triangular shape, and one side of the back-up spring is a vulcanized bonding surface with the reaction disk body.

``Function'' According to the above structure, the brake feeling does not worsen unlike when the back spring is configured as a plate, and one side of the almost triangular cross section is used as the vulcanized adhesive surface with the reaction disk body. Therefore, the filling pressure of the material filled into the mold acts on the vulcanized adhesive surface to press and fix the back-up spring to the mold.

Therefore, it is less likely that material will get wrapped around between the mold and the back-up spring, or that parts of the back-up spring may be twisted into a twisted state, thereby reducing the incidence of defective products. It becomes possible to reduce the

"Example" The present invention will be explained below with reference to the illustrated example.
In FIG. 1, a power piston 2 is slidably provided in a shell 1 of a brake booster, and a diaphragm 3 is attached to the back surface of the power piston 2. The interior of the shell 1 is divided into a constant pressure chamber 4 at the front and a variable pressure chamber 5 at the rear. A valve body 6 is integrally provided on the shaft portion of the power piston 2, and a valve mechanism 7 for switching the flow path is housed within the valve body 6.

The valve mechanism 7 has a first valve formed in the valve body 6.
A valve seat 10, a second valve seat 12 formed on the valve plunger 11, and a power piston 2 on both valve seats 10, 12.
A valve body 14 is provided which is seated from the rear side, that is, from the right side in FIG. 1, by the elastic force of a spring 13. The outside of the seat portion between the first valve seat 10 and the valve body 14 communicates with the constant pressure chamber 4 via a passage 15 formed in the valve body 6, and furthermore, the inside of the constant pressure chamber 4 is connected to a negative pressure chamber provided in the shell 1. It communicates with a negative pressure source such as an engine intake manifold via a pressure introduction pipe 16.

On the other hand, the intermediate portions of the seals between the first valve seat 10 and the valve body 14 and between the second valve seat 12 and the valve body 14 communicate with the variable pressure chamber 5 through a passage 17 formed in the valve body 6, and further The second valve seat 12 and the valve body 1
The inner side of the seat portion with 4 is communicated with the atmosphere via a filter 18.

Also, a valve plunger 1 constituting the valve mechanism 7
1 is connected to an input shaft 25 that is linked to a brake pedal (not shown), and the valve plunger 11 is connected to a push rod 27 via a reaction disk 26.
I am trying to link it to. This push rod 27 passes through the seal member 28 and projects to the outside of the shell 1, and is interlocked with a piston of a master cylinder (not shown). Furthermore, the power piston 2, valve body 6, etc. are normally held at the non-operating position shown in the figure by a return spring 29.

As shown in an enlarged view in FIG. 2, the tip of the valve plunger 11 is slidably fitted into a small diameter hole 6a formed in the shaft of the valve body 6. The right end base 27 of the push rod 27 is located in the large diameter hole 6b connected to the front.
A is slidably fitted thereinto, and the reaction disk 26 is also fitted therein.

The reaction disk 26 is a disk-shaped reaction disk body 3 made of soft rubber.
0, and the push rod 27 is attached to the end surface of the push rod 27 side of the reaction disk body 30.
The back-up spring 31 is arranged along the contour of the right end base 27a of the reaction disk, and the back-up spring 31 is manufactured from rubber or soft synthetic resin having a harder hardness than the reaction disk main body 30. As a result, the reaction disk body 30 is connected to the valve body 6 and push rod 2.
7 and prevents it from being caught between the two. The cross section of the back-up spring 31 is formed into a substantially triangular shape, and one side thereof serves as a vulcanized bonding surface 31a that is vulcanized and bonded to the reaction disk body 30.

In the above configuration, when the brake pedal (not shown) is depressed and the input shaft 25 and the valve plunger 11 are moved to the left, the valve body 14 is moved toward the valve body 6.
The valve body 14 is seated on the first valve seat 10 of the valve plunger 11 to cut off communication between the variable pressure chamber 5 and the constant pressure chamber 4, and the valve body 14 is separated from the second valve seat 12 of the valve plunger 11, so that the atmosphere and the variable pressure chamber 5 are separated from each other. communicate. As a result, atmospheric air is supplied into the variable pressure chamber 5, and the pressure difference between the front and rear sides of the power piston 2 causes the power piston 2 to move toward the return spring 29, similar to a conventionally well-known brake booster.
The vehicle is moved forward against the repulsive force of the vehicle, and a braking action is performed.

At this time, the brake reaction force applied to the push rod 27 is transmitted from the push rod 27 via the reaction disk 26 to the valve plunger 11, and further via the input shaft 25 to a brake pedal (not shown).

In this reaction force transmission state, the back-up spring 31 of the reaction disk 26 has relatively sufficient hardness, so that the back-up spring 31 is connected to the valve body 6 and the push rod 27.
There is no chance that it will get caught between the two and be damaged. Therefore, it is possible to prevent the flexible reaction disk body 30 from being caught between the valve body 6 and the push rod 27 and being damaged, as would be the case without the backup spring 31.

In addition, the cross section of the back-up spring 31 is approximately triangular, and the vulcanized adhesive surface 3 on one side thereof
1a is vulcanized and bonded to the reaction disk main body 30, so when manufacturing the reaction disk 26, the filling pressure of the material filled into the mold (not shown) acts on the vulcanization bonding surface 31a, causing back-up. The ring 31 is pressed and fixed at a predetermined set position within the mold.

As a result, material may wrap around between the mold and the back-up spring 31, or the filling pressure may displace a portion of the back-up spring 31 from its predetermined set position and deform it into a twisted condition. Therefore, the incidence of defective products can be reduced.

Note that the cross section of the backup spring 31 does not need to be exactly triangular, but may be approximately triangular as a whole so that it is difficult to move from the required set position when receiving filling pressure.

Further, as in the illustrated embodiment, a protrusion 30a is formed on the shaft portion of the valve plunger side end surface of the reaction disk main body 30, and the protrusion 30a is fitted into the small diameter hole 6a of the valve body 6. , a back-up spring having a roughly triangular cross-section corresponding to the back-up spring 31 is vulcanized and adhered around the protruding portion 30a, and the back-up spring connects the reaction disk body 30 to the valve body 6 and the valve plunger. It may be possible to avoid being caught between 11 and 11.

"Effects of the Invention" As described above, according to the invention, the approximately triangular cross-sectional shape of the back-up spring prevents material from wrapping around between the mold and the back-up spring during production of the reaction disk. By deforming a part of the back-up spring into a twisted state, it is possible to effectively prevent damage, thereby reducing the incidence of defective products.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is an enlarged sectional view of the main part of FIG. 1. 6... Valve body, 11... Valve plunger,
26... Reaction disk, 27... Push rod, 30... Reaction disk body,
31... Backup spring, 31a... Vulcanized adhesive surface.

Claims (1)

[Scope of Claim for Utility Model Registration] A reaction disk body that is interposed between a valve plunger and a push rod and transmits the brake reaction force applied to the push rod to the valve plunger, and a reaction disk body that is integrally vulcanized and bonded to the reaction disk body. In a reaction disk of a brake booster equipped with a back-up spring that prevents the disk body from being caught between the valve body and the push rod or valve plunger, the back-up spring has a substantially triangular cross section. A reaction disk for a brake booster, characterized in that one side of the reaction disk is a vulcanized bonding surface to the reaction disk body.