JPS5815339B2 - Shinkubairiyokusouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a vacuum booster used in a brake device of a vehicle or the like.

The vacuum booster has a diaphragm that defines two chambers inside the shell body, and the differential pressure received by the diaphragm is transmitted to the output rod on one side of the plurality of reaction levers via the piston brake roller. There is a type in which the reaction force is transmitted to the input rod by the other surface of the reaction lever.

By the way, in conventional models where the valve body and piston plate are integrally molded from a resin material, the hardness is low, so the fulcrum where the reaction lever comes into contact is prone to wear and dents, reducing durability. There was a problem.

Therefore, in order to increase the hardness of only the part that becomes the fulcrum of the reaction lever, some other materials, such as piano wire, are used, but in this case, the same number of this part as the reaction lever is required, which reduces the number of parts. increase,
Further, there were drawbacks such as an increase in the number of assembly steps.

The present invention aims to provide a vacuum booster that eliminates these drawbacks.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. 1 is a shell body of a vacuum booster; a front shell 2;
, and rear shell 3 are combined to form a container shape.

A diaphragm 4 is stretched inside the main body 1, and a front chamber 5 and a rear chamber 6 are defined within the main body 1 by this diaphragm 4 and a valve mechanism described later.

A pipe 7 communicating with the front chamber 5 is attached to the shell body 1, and this pipe 7 is connected to an intake pipe of the engine.

Reference numeral 8 denotes an input rod, whose base end (right end in the figure) is connected to a brake pedal (not shown).

The tip of the input rod 8 is fitted into a plunger 10 fitted into a cylinder portion 9a of the valve body 9, and is adapted to press the plunger 10 to the left in the figure during braking.

This plunger 10 and the cylinder portion 9a of the above-mentioned valve body 9 have a valve seat 10a at the right end in the figure, respectively.
9b is formed, and as the bra 10 moves,
Poppet valve 1 being pushed by spring 11
2 are still in contact with and separated from the valve seats 10a and 9b.

Note that when inactive, the poppet valve 12 is in contact with the valve seat 10a and is spaced apart from the valve seat 9b, as shown in FIG. 9c, but both chambers 5 and 6 are cut off from the atmosphere (the right side of the valve body 9 from the poppet valve 12 communicates with the atmosphere).

The aforementioned diaphragm 4 and the inner circumference of a piston plate 13 provided along the diaphragm 4 are fitted into the outer circumference of the valve body 9 .

This piston plate 13 receives differential pressure together with the diaphragm 4.

On the left side of the piston plate 13, as shown in FIGS. 2 and 3, the outer peripheral portion is provided with a rear crayon lever 1, which will be described later.
51 rule, the outer peripheral edge 14a is bent to cover the reaction lever 15, and the inner peripheral part is bent in the opposite direction and a metal plate 14b formed on the inner peripheral edge is located. A portion 14b is fitted and attached to the valve body 9.

This plate 14 is provided with cutouts 14c at a plurality of locations (three locations in this embodiment) near its outer periphery.
As a result, an edge portion 14d is formed in a portion thereof.

This edge portion 14d and the shoulder portion 10 of the plunger 10
b, both ends 15a of the reaction lever 15,
15b is engaged.

A plurality of reaction levers 15 (three in this embodiment) are provided corresponding to the notches 14C, and each has a substantially rectangular shape.

In this way, one end of the reaction lever 15 has a rough plate 1.
When engaged with the edge portion 14d of the plate 14, the outer peripheral edge 14a of the plate 14 acts to prevent the reaction lever 15 from falling off.

Reference numeral 16 denotes a cover plate, which is shaped like a plate with a bent cross section as shown in the figure, and is pressed to the right by a return spring 17 interposed between a portion near its outer periphery and the inside of the front shell 2. This applies a rightward force to the piston plate 13, diaphragm 4, and valve body 9.

Reference numeral 18 is a fulcrum plate having a U-shaped cross section that is in contact with the reaction lever 15 at the tip 18a, and 19 is an output rod that is fitted into the center of the fulcrum plate 18.

In the device configured in this way, when thrust is applied to the input rod 8, the stationary valve body 9
Inside, the plunger 10 and the poppet valve 12 pushed by the spring 11 move to the left.

Next, the poppet valve 12 is attached to the valve seat 9b of the valve body 9.
contact, and the communication between the front chamber 5 and the rear chamber 6 is cut off.

When the input rod 8 is further pressed, the plunger 1
The valve seat 10a of 0 is removed from the surface of the poppet valve 12, and at the same time, the atmosphere enters the rear chamber 6 through the gap and the passage 9d.

Due to this atmospheric pressure, the diaphragm 4 generates a pressure difference on both sides thereof, and the boosting operation starts.

The auxiliary force accompanying the differential pressure is transmitted to the reaction lever 15 via the piston plate 13 and the edge portion 14d of the plate 14, and this differential pressure is transmitted to the output rod 19 via the fulcrum plate 18 on one surface of the reaction lever 15. will be done.

Further, the reaction force is transmitted to the input rod 8 via the plunger 10 on the other side of the end 15b of the reaction lever 15.

Then, as the valve body 9 moves, the valve seat 10a of the plunger 10 seats on the poppet valve 12, and becomes stationary.

If the input rod 8 is further depressed, a similar operation will be performed.

As explained in the embodiments above, the present invention has an outer circumferential edge formed between a piston plate and a reaction lever by bending the outer circumferential portion toward the reaction lever so as to cover the reaction lever, and forming an outer circumferential edge at a position near the outer circumference. A metal plate with a notch formed in the metal plate is interposed, and a part of the reaction lever is brought into contact with the edge of the notch of the metal plate to serve as a pivot point for the reaction lever. Since the edge of the metal plate is used as the fulcrum, the fulcrum of the reaction lever does not change, and variations in boost characteristics and hysteresis can be reduced.

Further, since it is only necessary to provide a notch, processing is easy, and if heat treatment is performed to increase the hardness, the durability will be further improved and the life will be extended.

The outer peripheral edge of the metal plate can prevent the reaction lever from falling off.

Furthermore, the number of parts can be reduced compared to the conventional one, and therefore the number of assembly steps is also reduced, which is advantageous in terms of cost, and when manufactured by plate loveless, there is an advantage that dimensional control is easy.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view of an embodiment of the present invention, FIG. 2 is a front view of a plate used in the present invention, and FIG.
The figure is a central sectional view of FIG. 2. 1...Body, 4...Diaphragm, 8
...Input rod, 9...Valve body, 10...Plunger, 12...
・Poppet valve, 13...Piston plate, 14...Plate, 14a...Outer rim, 14C...Notch, 14d... Plate edge, 15... Reaction lever, 18... Fulcrum plate, 19...
...output rod.

Claims (1)

[Claims] 1 It has a diaphragm that defines two chambers in the shell body, and the differential pressure received by the diaphragm is transmitted to the output rod on one surface of the plurality of reaction levers via the piston plate, and this reaction force is applied to the reaction force. In a vacuum booster of the type in which transmission is transmitted to the input rod on the other side of the lever, a vacuum booster is provided between the piston plate and the reaction lever so that the outer peripheral portion faces the reaction lever and covers the reaction lever. A metal plate is bent to form an outer periphery and a notch is formed near the outer periphery, and a part of the reaction lever is brought into contact with the edge of the notch of the metal plate to rotate the reaction lever. A vacuum booster characterized in that the reaction lever is prevented from falling off by using an outer peripheral edge of the metal plate as a fulcrum.