JPS61202970A - Negative-pressure type magnification device - Google Patents

Abstract

PURPOSE:To make the operating force to be generated optionally changeable by providing a constant-pressure chamber and a variable-pressure chamber which is freely communicated or cut off internally, both partitioned by a movable wall in a body, and dividing this variable-pressure chamber into two rooms with a bulkhead so that both rooms can be communicated or cut off by a one- way valve and a solenoid valve. CONSTITUTION:A body 11 internally divided into a constant-pressure chamber 16 and a variable-pressure chamber 17 by a movable wall 14 and a resin hub 15 is provided. a control valve 28 operated by an input rod 25 is stored in the hub 15 hermetically and slidably penetrating the body 11. The variable- pressure chamber 17 is cut off from the constant-pressure chamber 16 and, on the other hand, is communicated to the atmosphere by the operation of this control valve 28, thereby the operating force in response to the pressure difference is applied to the movable wall 14. In this case, the variable-pressure chamber 17 is divided into two variable-pressure rooms 17a, 17b by a bulkhead 21 provided in the body 11. Both variable-pressure rooms 17a, 17b can be communicated together via a one-way valve 22 made with an annular seal and a valve 24 closed by an input signal.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a pneumatic booster used for reducing brake pedal depression force and clutch pedal depression force of automobiles, and in particular, to a pneumatic booster used for reducing brake pedal depression force and clutch pedal depression force of automobiles. The interior is divided into a constant pressure chamber and a variable pressure chamber connected to a negative pressure source by a movable wall, and a control valve disposed in a hub connected to the movable wall is operated manually to isolate the variable pressure chamber from the constant pressure chamber. This relates to a negative pressure booster that generates operating force on a movable wall by introducing atmospheric air, and transmits the operating force of the movable wall and the operating force applied to the control valve to the output member via a reaction mechanism. be.

(Prior Art) In conventional pneumatic boosters of this type, pressure gas is allowed to flow into the variable pressure chamber only by manually operating a control valve to obtain operating force on the movable wall. However, in order to avoid having to operate the parking brake when the vehicle continues to stop after pressing the brake pedal on a slope, or to prevent the so-called creep phenomenon in vehicles equipped with a transmission with a torque converter, Japanese Patent Application Laid-Open No. 58-10586 is a device that can continue to generate operating force on a movable wall even if the control valve is released without continuing to step on the brake pedal or operating the parking brake.
Publication No. 6, JP-A-57-130845, Utility Model Application No. 5
There are those described in JP-A No. 8-75068 and JP-A-55-10'6854.

In the device described in Japanese Patent Application Laid-Open No. 58-105866, pressure is transformed by energizing an electromagnetic device placed inside the body and fixed to a movable wall to operate a control valve via a lever in the same way as manual operation. Air is allowed to flow into the chamber, generating an operating force on the movable wall to maintain the brake applied even after the brake pedal is released.

What is described in Japanese Patent Application Laid-Open No. 57-130845 is
A fluid pressure actuator or electromagnetic device that operates the control valve's operating rod instead of human power is placed outside the body or inside the hub, and these actuators or electromagnetic devices operate the control valve to allow atmospheric air to flow into the variable pressure chamber. It generates an actuating force on the wall.

In addition, the device described in Japanese Utility Model Application Publication No. 58-75068 has a movable seat for controlling the communication between the variable pressure chamber and the atmosphere in the control valve, and uses an electromagnet device installed in the hub to move the movable seat between the two chambers. It is moved in the blocking direction to allow air to flow into the variable pressure chamber.

What is described in Japanese Patent Application Laid-Open No. 55-106854 is
A solenoid valve provided inside the hub blocks communication between the constant pressure chamber and the variable pressure chamber via the control valve, and a solenoid valve provided outside the body allows atmospheric air to flow into the variable pressure chamber.

(Problems to be Solved by the Invention) However, as described in Japanese Patent Application Laid-open No. 58-105866 and Japanese Patent Application Laid-open No. 57-130845, the control valve is operated by an electromagnetic device or a fluid pressure actuator, similar to manual operation. In configurations in which the movable wall is actuated, the electromagnetic device or fluid pressure actuator is required to have an output sufficient to counter the recoil force applied by the reaction mechanism. The problem is that the actuator becomes very large, making it difficult to put it into practical use.

Also, Japanese Unexamined Patent Publication No. 57-130845 and Utility Model Application No. 58-7
In a device that incorporates an electromagnetic device into the hub, such as the one described in Publication No. 5068, the diameter of the hub inevitably increases, and the negative pressure in the constant pressure chamber and the large increase in pressure due to the hub protruding outside the body The force constantly applied to the hub increases due to atmospheric pressure, which necessitates reinforcing the return spring of the movable wall.In addition, the pressure-receiving area of the movable wall that receives the pressure of the variable pressure chamber decreases, so in order to compensate for this decrease, the movable wall This requires an increase in the outer diameter of the booster, resulting in problems such as an increase in the size of the booster.

Furthermore, in the method described in JP-A-55-106854, two solenoid valves are required, and the solenoid valves are expensive, making it expensive. There are problems such as the booster becoming larger.

The actuation force generated on the movable wall by the operation of the electromagnetic device, fluid pressure actuator, and solenoid valve can be adjusted to an arbitrary magnitude so as not to place an unnecessary load on the brake device, and it is desirable that the means for achieving this be of a simple configuration. However, these conventional devices have the problem that the operating force generated on the movable wall remains unchanged by the operation of an electromagnetic device, a fluid pressure actuator, a solenoid valve, etc. The problem is that a control mechanism is required to make the output variable, making the configuration extremely complicated.

Therefore, the technical object of the present invention is to eliminate the problems seen in the conventional device by improving the structure that continues to generate an operating force on the movable wall even when the control valve is released.

[Structure of the Invention] (Means for Solving the Problems) The technical means taken by the present invention to solve the above-mentioned technical problems is to divide the pressure-changing chamber into a partition wall disposed within the body and fixed to the body. A one-way valve that is divided into a first variable pressure chamber that is always in communication with a control valve and a second variable pressure chamber that is adjacent to the movable wall, and that allows gas to flow from the first variable pressure chamber to the second variable pressure chamber. A valve is provided that allows gas to flow from the second variable pressure chamber to the first variable pressure chamber, but blocks this gas flow by inputting a signal.

(Function) In the present invention which takes such technical measures, when the control valve is manually operated, the atmosphere flows into the second variable pressure chamber, and this air flows into the second variable pressure chamber through the one-way valve. A pressure difference is applied to the movable wall and an actuation force is generated. Further, when the operation of the control valve is released, the atmosphere in the second variable pressure chamber flows into the first variable pressure chamber through the valve, and flows from the first variable pressure chamber into the control valve. Then, if a signal input is applied to the valve while the control valve is operated to cause the valve to close, the atmosphere is sealed in the second variable pressure chamber, so that the movable wall can maintain the operating force. In this case, the output of the booster will decrease by the amount of the operator's power, but if you feel that the output is insufficient due to this decrease, apply a greater amount of operator power than the previous time to operate the control valve and move it to the second variable pressure chamber. By allowing air at a higher pressure than the first variable pressure chamber to flow into the first variable pressure chamber, the air in the second variable pressure chamber flows into the first variable pressure chamber through the one-way valve, increasing the pressure difference between the first variable pressure chamber and the constant pressure chamber. Since the actuation force of the movable wall increases, the output of the booster when released is greater than before.

As described above, in the present invention, the bulkhead, the one-way valve, and the valve that responds to human signal input generate an operating force on the movable wall in the state in which the operator's input is released, and the closing operating force of the valve that responds to the signal input is generated. needs to be small enough to resist the pressure difference between the two variable pressure chambers, so if an electromagnetic device is used as the means for generating the closing actuation force, it can be much smaller than conventional ones, and the one-way valve can also be smaller. Therefore, as will be clear from the examples described later, the booster can be made smaller. Also, with such a simple configuration, the operating force generated on the movable wall can be controlled by the operating force applied to the control valve. can be easily adjusted to any value.

(Embodiment) An embodiment of the present invention will be described below based on the drawings. An embodiment in FIG. 1 is used as a brake booster for an automobile, and the body 11 of the pneumatic booster 10 is made of a metal plate. The body component members 12 and 13 are integrally joined together. The interior of the body 11 is divided by a movable wall 14 and a resin hub 15 into a constant pressure chamber 16 (connected to the intake pipe of an automobile engine and supplied with negative pressure) and a variable pressure chamber 17. Sealing and guiding device 18 for body component 13
The movable wall 14 has a cylindrical portion 15a that protrudes outside the body through the cylindrical opening 13a in which the movable wall 14 has a cylindrical opening 13a attached thereto. It consists of a plate 19 and a rubber diaphragm 20 whose thick inner circumferential portion 20a and thick outer circumferential portion 20b are attached to the hub 15 and the body 11 in an airtight manner, respectively.

The variable pressure chamber 17 has a partition wall 21 fixed to the body 11 at its outer circumference, and is attached to the inner circumference of the partition wall 21 so that its lip 22a slidably contacts the outer circumference of the cylindrical portion 15a of the hub 15. It is divided into a first variable pressure chamber 17a and a second variable pressure chamber 17b by an annular seal 22 made of rubber. The lip 22a of this seal 22 is connected to both pressure chambers 17a and 17.
b due to the pressure difference between the first variable pressure chamber 17a and the second variable pressure chamber 1
It constitutes a so-called one-way valve that allows gas to flow to the second variable pressure chamber 17b but blocks the gas flow from the second variable pressure chamber 17b to the first variable pressure chamber 7a. Rubber grommet seal 23 on partition wall 21
The valve 24 attached through the valve is for controlling the gas flow from the second variable pressure chamber 17b to the first variable pressure chamber 17a, and the valve body 24b is attached to the valve seat 24 by a weak spring 24a.
C, the first transformer chamber 17a is in contact with the second
Normally, the gas flow is not allowed to flow into the variable pressure chamber 17b, and the gas flow from the second variable pressure chamber 17b to the first variable pressure chamber 17a is allowed, but the lead wire inserted through the body component 13 is connected to the electromagnetic coil 24d. When a current is applied, the magnetic force and spring 24a cause the valve body 24b to come into contact with the valve seat 24C, thereby blocking the flow of gas from the second variable pressure chamber 17b to the first variable pressure chamber 17a.

Inside the hub 15, there is a plunger 26 connected to the left end in FIG. 1 of an input rod 25 connected to a brake pedal (not shown), and a plunger 26 attached to the hub 15 and formed at the right end of the plunger 26 in FIG. sea 1-2
6a and a rubber poppet pulp 27 that faces the sheet 15b formed on the hub 15 and is urged toward these by a suffling.
When no operating force is applied to the left in FIG.
Both chambers 16 and 17d are connected to the constant pressure chamber 16 through 5d.
The well-known control valve 28 eliminates the pressure difference between the two chambers 16 and 171 by communicating the variable pressure chamber 17 with the atmosphere when the input lot 25 is moved to the left in the drawing.
is built-in.

When the atmosphere flows into the first variable pressure chamber 17a due to the operation of the control valve 28 due to the operation of the input lot 25, the first variable pressure chamber 1
The atmosphere at 7a connects the lip 22a of the annular seal 22 to the hub 15.
The second pressure-changing chamber 17b is separated from the outer periphery of the cylindrical portion 15a.
Since the pressure flows into the second variable pressure chamber 17b, the pressure in the second variable pressure chamber 17b also increases, and an operating force is generated in the movable wall 19 due to the pressure difference between the constant pressure chamber 16 and the second variable pressure chamber 17ti. In addition, due to the operation of the control valve 28 accompanying the release of the input lot 25, the first pressure change chamber 17a
is communicated with the constant pressure chamber 16, and when the atmosphere in the first variable pressure chamber 17a flows out to the constant pressure chamber 16 and the pressure in the first variable pressure chamber 17a decreases, the atmosphere in the second variable pressure chamber 17b passes through the valve 24 and 1
Since the pressure flows out into the variable pressure chamber 17a, the pressure in the second variable pressure chamber 17b also decreases, the operating force of the movable wall 19 decreases, and the return spring 29 causes the movable wall 19 and the hub 15 to return.

When the input rod 25 is operated and a current is applied to the electromagnetic coil 24d of the valve 24 in a state where an operating force is generated in the movable wall 19, the atmosphere in the second variable pressure chamber 17b is changed to the first one by the closing operation of the valve 24. It is no longer possible to flow out to the variable pressure chamber 17a, and the control valve 28 is activated when the input lot 25 is released.
Even if the pressure in the variable pressure chamber 17a decreases, an operating force continues to be generated in the movable wall 19 due to the pressure difference between the constant pressure chamber 16 and the second variable pressure chamber 17b. In addition, when the valve 24 is closed, the input lot 25
is operated again to change the pressure in the first variable pressure chamber 17a to the second variable pressure chamber 1.
By making the pressure higher than that of 7b, the first variable pressure chamber 1
7a flows into the second pressure change chamber 17b and the second pressure change chamber 1
Since the pressure at 7b increases, the operating force that continues to be generated in the movable wall 19 can be increased.

The actuation force of the movable wall 19 is transmitted to the piston of the brake mask cylinder (not shown), and the plunger 26
An output rod 31 having a built-in rubber reaction member 30 is attached to the hub 15 in order to apply a reaction force to the operation, and is prevented from falling off by a retainer 32.

Another embodiment in FIG. 2 shows an example in which the one-way valve and the valve are arranged outside the body. In this embodiment, the seal 22 is configured as a simple seal that also blocks the flow of gas from the first variable pressure chamber 17a to the second variable pressure chamber 17b, and the pipe portion 21a provided on the partition wall 21 is connected to the body component 13 in an airtight manner. The body structural member 1
3 is also formed with a pipe portion 13b, and these both pipe portions 21
A one-way valve 33 and a normally open valve (electromagnetic valve) 34 are arranged in parallel in the passage connecting a and 13b.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to continue to generate a large operating force on the movable wall even when the operation of the control valve is released, and the operating force generated on the movable wall can be easily adjusted to an arbitrary magnitude. It is adjustable, has a simple configuration, and can be made smaller than conventional devices.

Further, since the valve is attached to a fixed partition wall, the durability of the member (for example, a lead wire) that provides signal input to the valve is increased, and the reliability of the device is improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the invention, and FIG. 2 is a longitudinal sectional view of another embodiment of the invention. Explanation of symbols 10... Negative pressure booster, 11... Pode, 15.
...Hub, 16...Constant pressure chamber, 17a...First pressure change chamber, 17b...Second pressure change chamber, 21...Partition wall, 22...
- Annular seal constituting a one-way valve, 24...Valve, 28
...Control valve, 33...One-way valve, 34...Valve

Claims (1)

[Claims] The interior of the body is divided into a constant pressure chamber and a variable pressure chamber connected to a negative pressure source by a movable wall, and the hub is connected to the movable wall and extends through the body in an airtight and slidable manner to protrude outside the body. A control valve installed inside the chamber is manually actuated to isolate the variable pressure chamber from the constant pressure chamber and allow atmospheric air to flow in to generate an operating force on the movable wall. In the negative pressure booster configured to transmit the pressure to the output member via a reaction mechanism, a first variable pressure chamber is configured to constantly communicate the variable pressure chamber with the control valve by a partition wall disposed within the body and fixed to the body. and a second variable pressure chamber adjacent to the movable wall, and a one-way valve that allows gas to flow from the first variable pressure chamber to the second variable pressure chamber; A negative pressure booster equipped with a valve that allows gas flow but blocks this gas flow by inputting a signal.