JPS628338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a negative pressure booster, in which the inside of a pair of front and rear booster shells is housed in a booster piston that can freely reciprocate back and forth, and is connected to a negative pressure source and controlled by a booster piston. A pressure difference is formed to cause the booster piston to follow when the input rod, which is connected to the booster piston so as to move forward and backward, forms a constant negative pressure chamber or a variable pressure chamber whose communication with the atmosphere is switched and controlled via a valve. In the negative pressure booster, the input rod is connected to the control valve so that the pressure is generated between the two chambers, and a booster output is generated by the pressure difference, and the tip of the input rod is connected to the inner wall of the insertion hole of the booster piston. an annular first valve seat body formed in a spherical shape so as to be slidable and swingable, and having a sliding portion that slides in contact with the spherical tip portion and a first valve seat that seats on the valve head of the control valve; The present invention is characterized in that the rocking of the input rod does not affect the seating relationship between the first valve seat and the control valve.

The purpose of this is to prevent the valve head of the control valve from separating from the first valve seat due to the swinging of the input rod that occurs when the input rod moves back and forth in the front and rear directions due to braking operation. .

An embodiment shown in the drawings will be described below.

This device is integrally equipped with a servo mechanism A, a control valve mechanism B, a hydraulic pressure generation mechanism C, and an actuation mechanism D.

First, the servo mechanism A will be explained. 1 is a front shell that is integrally molded with a master cylinder body 42 that houses a hydraulic pressure generation mechanism C, which will be described later.
is a rear shell in which supporting arms 60 and 61 that support an operating lever 62 and an operating wire 65 of an operating mechanism, which will be described later, are integrally molded. The interior of the housing is divided into a constant negative pressure chamber 6 and a variable pressure chamber 7 by the booster piston 4 and a diaphragm 5 connected to its back surface. The variable pressure chamber 7 is constantly connected to the intake manifold (not shown) of the internal combustion engine, which is a negative pressure source, through a hose connector 8 containing a built-in negative pressure chamber 6 or The air inlet 40 is alternately connected to an air inlet 40 opened in a dust boot 38 provided in the rear extension tube 2a of the rear shell 2. The booster piston 4 is always urged in the backward direction by the booster piston 9 which is always contracted in the negative pressure chamber 6. In addition, a boss 12 in which a stepped hole 11 for accommodating the reaction mechanism 10 is formed is raised on the front surface of the central part of the booster piston 4, and the stepped hole 11 has a large diameter hole 13 opening in the front surface, and a large diameter hole 13 opening in the front surface, and a large diameter hole 13 in the back thereof. The small diameter hole 14 is connected to the control valve mechanism B side and is open to the control valve mechanism B side.The small diameter hole 14 has a reaction plate 15, and the large diameter hole 13 has a reaction rubber 16.
The output rod 1 provided on the front side of the rubber 16
7 detects the reaction received during braking and transmits it to the driver.

Next, the control valve mechanism B will be described. Reference numeral 18 denotes a valve cylinder extending rearward from the center of the booster piston 4, and is slidably supported by a bush 19 provided on the extension cylinder 2a. 20 is a rod stopper provided at the front of the bush 19, and 21 is a piston seal provided at the rear.

Reference numeral 22 designates an input rod having a spherical tip 22a, which is inserted into the valve cylinder 18, and the frontmost portion 22b of the tip 22a is brought into contact with the arc-shaped recess 15a formed on the rear surface of the reaction plate 15. The input rod 22 is slidably and swingably supported in the hole 23 by sliding the side surface 22C of the input rod 22a onto the inner periphery of the support hole 23. This input rod 22 is the valve cylinder 18
The valve stopper 25 is fixed to the inner peripheral wall of the rod 22 with a snap ring 24, and the spring seat 27 is provided on the shaft of the rod 22 so as to be movable rearward with an E ring 26. It is fired in the backward direction.

29 is an annular first valve seat body made of relatively hard rubber or synthetic resin, and a first valve seat body is provided on the rear annular periphery.
The valve seat 29a is attached to the front annular periphery by a sliding portion 29b that is in close contact with the spherical surface of the tip 22a of the input rod 22 under normal conditions.
are formed respectively. 30 is a second valve seat formed on the inner wall of the valve cylinder 18 so as to surround the first valve seat 29a;
Reference numeral 1 designates a control valve, such as a poppet valve, whose base end 31a is clamped to the valve cylinder 18 by a valve stopper 25, and is made of an elastic material such as rubber, with a thin intermediate portion 31b extending radially inward from the base end 13a. A thick-walled valve head 31c facing both valve seats 29a and 30 is connected to the inner peripheral end of the intermediate portion 31b, and the valve head 31c
A reinforcing plate 32 is embedded in the reinforcing plate 32, and a valve spring 33 is applied to the reinforcing plate 32 in order to urge the valve head 31c toward both valve seats 29a and 30. This valve head 31c is in close contact with the first valve seat 29a in normal conditions, and is arranged with a clearance l from the second valve seat 30 as shown. The outer periphery of the second valve seat 30 is the booster piston 4
The intermediate portion between the first and second valve seats 29a and 30 is connected to the negative pressure chamber 6 through a passage 34, and the intermediate portion between the first and second valve seats 29a and 30 is connected to another passage 3.
It is always in communication with the variable pressure chamber 7 via 5.

36 is an annular fitting groove formed on the outer periphery of the extension tube 2a, and 37 is an annular fitting groove formed in the extension tube 2a at a position above the groove 36.
A communication hole 38 passing through the inner periphery of a is a dust boot, and an annular groove 39 is formed on the inner periphery of one end edge 38a, and an air inlet 40 is formed in a part of the annular groove 39 to communicate with the groove 39 from the outer periphery. The introduction port 40 is connected to the communication hole 3.
7 and the fitting groove 36 so that the lip 38a is shifted by about half a turn from the fitting groove 36.
The other end edge 38b is fitted into the annular groove 41 formed in the shaft of the input rod 22, and the annular groove 3 is fitted into the annular groove 3.
9. The inside of the first valve seat body 29 and the atmosphere inlet 40 are always communicated through the communication hole 37 and the inside of the poppet valve 31.

Next, the hydraulic pressure generating mechanism C built in the master cylinder body 42 will be explained.
The rear end of the piston 44, which is slidably provided within the cylinder 43, penetrates a sealing member having a rod seal 46 in the plates 45, 45 provided between the constant negative pressure chamber 6 and the cylinder 43, and is inserted into the constant negative pressure chamber 6. The output rod 17 is fitted within the cylinder 43, and is pressed against the base of the output rod 17 by a return spring 47 compressed within the cylinder 43. 48 is a snap spring, and 49 is an atmospheric communication hole. A hose connector 51 is attached to the master cylinder body 42 via an O-ring 50, and communicates with a fluid chamber 54 via a reservoir 52 and a supply port 53, and with a hydraulic pressure chamber 56 via a relief port 55. As the wheel moves forward, hydraulic pressure is sent to the wheel cylinder via the discharge port 57. 58 and 59 are cap seals.

Note that the master cylinder body 42 may be formed separately from the front shell 1 and the two may be integrally attached.

Next, the actuation mechanism D will be described. An operation lever support arm 60 and an operation wire support arm 61 are integrally protruded from the rear of the rear shell 2 at opposing positions with the input rod 22 in between. Reference numeral 62 denotes an input transmission operating lever, and one end 62a is rotatably supported by the operating lever support arm 60 by a pivot pin 63. 64 is a stopper for the pin 63.

Reference numeral 65 denotes an operating wire, one end of which is locked to the tip 62b of the operating lever 62 via a mounting bracket 66 to serve as a force point 67, and the other end is connected to the handlebar 68 of the motorcycle.
The brake lever 69 is connected to the brake lever 69 provided in the brake lever 69. This operating wire 65 is connected to a notch 61b having the width of the operating wire formed in the support portion 61a of the operating wire support arm 61.
The adjustment bolt 70a provided at one end of the wire case 70 is inserted into the support portion 61a.
a, and a spring 72 is compressed between the tip 62b of the operating lever 62 and a nut 71 screwed onto the adjustment bolt 70a. 61 support point 61c and the force point 67 of the operating lever 62
Adjusting the distance between. and input rod 22
The rear end is brought into contact with an action point 74 formed between the pivot support point 63a and the force point 67 of the operating lever 62, and the lever 62 limits the backward limit of the input rod 22. Therefore, Natsuto 71 or 7
Adjust the position of the operating lever 62 by screwing the input rod 22, move the input rod 22 forward or backward, and open the poppet valve 3.
Adjust the clearance l between the first valve head 31c and the second valve seat 30 to set a predetermined gap, and then tighten the nut 73.
Alternatively, one of the bolts 71 may be used as a lock nut to lock the adjustment bolt 70a to the support portion 61a.

Further, since the point of action 74 of the input rod 22 is located between the respective support points 63a and 61c of the operating lever support arm 60 and the operation wire support arm 61, the distance R ₂ between the support point 63a and the force point 67 is the support point. 63
The distance R between a and the point of action 74 is greater than ₁ , and by applying a lever, a large action is applied with a small force to the rod 2.
The servo output can be improved without changing the size of the booster that can be applied to the booster.

Note that the operation wire 65 can also be operated by a brake pedal.

Further, among the tightening bolts 3, for example, the two left and right bolts 3a, 3a in FIG. 2 are formed long, so that the present device can be attached to a predetermined location by co-tightening.

Next, the operation of the above device will be explained.
The figure shows a normal state, in which the booster piston 4 and the input rod 22 are connected to the booster spring 9 and the return spring 28, so that the diaphragm 5 of the piston 4 is attached to the inner wall of the rear shell 2, and the rear end of the input rod 22 is attached to the operating lever 62. It is in contact with the point of action 74 of. In addition, the poppet valve 31 has a valve head 31c that is connected to the valve seat 2 of the first valve seat body 29 by the valve spring 33.
9a, and the sliding contact portion 29b is also in close contact with the tip 22a of the input rod 22, so the air pressure in the negative pressure chamber and the variable pressure chambers 6 and 7 are always balanced, and the booster piston 4 is under the control of the booster spring 9. be.

Now, when you squeeze the brake lever 69 to control the vehicle, the operating wire 65 is pulled and the operating lever 6
2 in the counterclockwise direction in FIG. 1, and the point of action 74 pushes the input rod 22. This input rod 2
2 moves forward, the valve head 31, which is urged forward by the valve spring 33, follows and moves forward.
The first valve seat 29a is seated on the second valve seat 30 to block communication between the two chambers 6 and 7, and the first valve seat 29a is seated on the valve head 31c.
The sliding contact portion 29b also separates from the tip 22a of the input rod 22, and opens two atmospheric passages to the variable pressure chamber 7, including the atmospheric inlet 40, the annular groove 39, the communication hole 37, the inside of the poppet valve 31, the atmospheric passage, and the passageway. It communicates with the variable pressure chamber 7 via 35. Therefore, the pressure in the chamber 7 is always higher than that in the negative pressure chamber 6, and due to the pressure difference, the booster piston 4 moves forward against the booster spring 9, and the operating piston 44 of the hydraulic pressure generating mechanism C is moved through the output rod 17. The vehicle is braked by moving the vehicle forward.

On the other hand, the tip 22a of the input rod 22 receives an actuation reaction force from the output rod 7 via the reaction plate 15 and the reaction rubber 16 as it moves forward, and the input rod 22, the operating lever 62, the operating wire 65, and the brake lever 69 are activated. The driver can sense the braking force through the sensor.

Next, when the brake lever 69 is released, the reaction force applied to the input rod 22 and the return spring 28
This causes the sliding portion 29b of the first valve seat body 29 to come into close contact with the tip 22a, and the first
The valve seat 29a is seated on the valve head 31c, and the seat on the second valve seat 30 is canceled to eliminate the pressure difference between the two chambers 6, 7, and the booster piston 4 is moved backward by the booster spring 9.

As described above, the present invention has a spherical tip end, is slidably and swingably attached to the insertion hole of the booster piston, and has a sliding contact portion that comes into sliding contact with the spherical portion, and a poppet valve valve on the other side. Since the first valve body is equipped with a first valve seat that is seated on the head, the valve will remain open even if the input rod swings due to pressing of the operating lever etc. when the negative pressure chamber and the variable pressure chamber are under constant negative pressure. The first valve seat of the first valve seat body is brought into contact with the valve head of the poppet valve 31 by the spring, the sliding part is pressed against the spherical end of the input rod, and the valve head of the poppet valve is brought into contact with the second valve head.
Until the input rod is seated on the valve seat, the input rod swings along the sliding contact portion of the first valve seat body, preventing air from flowing into the two chambers, and becoming in a servo state due to a drop in negative pressure. When the valve head of the poppet valve is seated on the second valve seat due to the advancement of the input rod, the gap between the valve head and the first valve seat and the gap between the sliding contact part and the tip of the input rod is Since the two are passages for introducing the atmosphere into the variable pressure chamber, the introduction of the atmosphere is smooth.

[Brief explanation of the drawing]

Fig. 1 is Fig. 2 showing an embodiment of the present invention.
The sectional view and FIG. 2 are rear views. A is a servo mechanism, B is a control valve mechanism, C is a hydraulic pressure generation mechanism, D is an operating mechanism, 1 is a front shell, 2 is a rear shell, 3 is a tightening bolt, 4 is a booster piston, 5 is a diaphragm, 6 is a A constant negative pressure chamber, 7 a pressure transformation chamber, 8 a hose connector, 10 a reaction mechanism, 17 an output rod, 18 a valve cylinder, 22 an input rod with a spherical tip 22a, and 29 a first valve seat body. , 29a is a first valve seat, 29b is a sliding contact portion, 30 is a second valve seat, 31 is a poppet valve, 31c is a valve head, 42 is a master cylinder body, 60 is an operation lever support arm, 61 is an operation wire support arm, 61a is a support part, 61c is a support point, 62 is an input transmission operation lever, 63a is a support point, 65 is an operation wire, 6
7 is a power point, 70 is a wire guide, 70a is an adjustment bolt, 71 and 73 are nuts, 72 is a spring,
74 is a point of action.

Claims (1)

[Claims] 1 Inside the pair of front and rear booster shells, a booster piston housed therein so as to be able to freely reciprocate back and forth controls communication between a constant negative pressure chamber connected to a negative pressure source and the constant negative pressure chamber or the atmosphere via a control valve. The input rod is connected to the control valve so that when the input rod, which is movably connected to the booster piston, moves forward, a pressure difference is generated between the two chambers to cause the booster piston to follow the input rod. In the negative pressure booster which connects to each other and generates a booster output based on the pressure difference, the tip of the input rod is formed into a spherical shape so as to be able to slide and swing on the inner wall of the insertion hole of the booster piston. providing an annular first valve seat body having a sliding contact portion that slides on the spherical surface portion and a first valve seat that can be seated on the valve head of the control valve;
A negative pressure booster characterized in that the rocking of the input rod does not affect the seating relationship between the first valve seat and the control valve.