JPH11157440A - Air control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air control valve of excellent responsiveness which can release the air pressure in an air master cylinder to the atmosphere in a short time when a transition is made from the brake applied condition to the released condition. SOLUTION: An air control valve 10 is installed between a brake valve and an air master cylinder, and is arranged so that the air pressure fed in pressure from the brake valve is led selectively to the air master cylinder or the led air pressure is decompressed, wherein the configuration includes a hold diaphragm 15 and decay diaphragm 17 to perform selective leading and shutting, and a one-way throttle valve 25 is furnished in the flow passage leading from the brake valve to the hold diaphragm, and an air pressure difference is generated in the decay diaphragm when the brake is released so as to open the decay diaphragm, and it is arranged so that the air pressure on the side with air master cylinder is released from the air exhaust chamber in the air control valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock / traction control air control valve suitable for a full air and air overhydraulic (AOH) brake system, and more particularly to a transition from a brake operating state to a brake releasing state. The present invention relates to an air control valve having excellent brake response, which can release the air pressure in an air master cylinder to the atmosphere in a short time.

[0002]

2. Description of the Related Art As an air control valve, a type shown in FIG. 4 has been well known. Referring to the drawings, a brake system using the air control valve will be described. In the drawing, 101 is an air tank, 102 is a brake valve, 103 is a brake pedal, 100 is an air control valve, 104 is an air master cylinder, and 105 is A brake cylinder 106 is a relay valve, and these constitute a brake system.

In this brake system, when the brake pedal 103 is depressed, the brake valve 102 opens,
Air corresponding to the depression force of the brake pedal 103 is supplied from the air tank 101 to the air control valve 100 by the relay valve 106, and the air control valve 1
00 acts on the air master cylinder 104, where the air pressure is converted to hydraulic pressure and the brake cylinder 1
05 can be operated to apply the brakes. The air master cylinder 104 may be omitted, and the air pressure may be directly supplied to the brake cylinder 105.

As shown in the figure, an air control valve 100 has an input chamber 111 communicating with a relay valve 106, an output chamber 112 communicating with an air master cylinder (air master) 104 side, and releases air pressure to atmospheric pressure. An exhaust chamber 113 is provided, and a hold valve 114, a hold diaphragm 115, a decay valve 116, and a decay diaphragm 117 are arranged in flow paths communicating with each other, as shown in the figure. The input chamber 111 communicates with the output chamber 112 via a hold diaphragm 115,
The output chamber 112 communicates with the exhaust chamber 113 via a decay diaphragm 117.

[0005] The hold valve 114 has a valve input port 114a, a valve output port 114b, and a valve exhaust port 114c. A plunger 114e for opening and closing the ports is disposed in the hold valve 114. The plunger 114e is provided with flow passage blocking members 114f and 114g at both ends. The plunger 114e is normally urged upward in the drawing by a return spring 114k, and the valve input port 114a and the valve output port are moved by the flow passage blocking member 114f. The valve 114b is shut off, and the valve output port 114b and the valve exhaust port 114c are communicated. Plunger 1
When the solenoid 114d is energized, the solenoid 14e moves downward from the illustrated state against the urging force of the return spring 114k to communicate the valve input port 114a and the valve output port 114b and to cut off the flow path shutoff member 114.
With g, the valve output port 114b and the valve exhaust port 114c are shut off.

The hold diaphragm 115 is made of an elastic material, and is normally urged in a direction to close the communication between the input chamber 111 and the output chamber 112 by a return spring 115b disposed on the side of the back pressure chamber 115a.

The decay valve 116 has a valve input port 116a, a valve output port 116b, and a valve exhaust port 116c. A plunger 116e for communicating and shutting off each of the ports is disposed in the decay valve 116. The plunger 116e is provided with flow passage blocking members 116f and 116g at both ends. The plunger 116e is normally urged downward in the drawing by a return spring 116k, and the valve blocking port 116g and the valve input port 116a and the valve discharge port. 116c, the valve output port 116b and the valve discharge port 116c are shut off, and the valve input port 116a is closed.
And the valve output port 116b. When power is supplied to the solenoid 116d, the plunger 116e
Moves upward from the state shown in FIG.
Valve input port 116a and valve output port 1
16b is shut off, and the valve output port 116b and the valve exhaust port 116c are communicated. The decay diaphragm 117 is made of an elastic material, and is always in the back pressure chamber 17.
The output spring 112b is urged in a direction to close the communication between the output chamber 112 and the exhaust chamber 113 by a return spring 117b disposed on the side a.

As shown in FIG. 4, the hold valve 114 having the above structure has a valve input port 114a of the hold valve 114 on the input chamber 111 side and a valve output port 1
14b is a back pressure chamber 115a of the hold diaphragm 115
The valve exhaust port 114c is disposed so as to communicate with the atmosphere, and when not operating, the input chamber 111 and the back pressure chamber 115
a is shut off by a hold diaphragm, and the back pressure chamber 115a communicates with the atmosphere through a valve exhaust port 114c. When the solenoid 114d of the hold valve 114 is energized to move the plunger 114e downward in the drawing, the input port 114a,
The valve output port 114b is communicated, the valve output port 114b and the valve exhaust port 114c are shut off,
The input chamber 111 and the back pressure chamber 115a communicate with each other, and the back pressure chamber 1
15a will be cut off from the atmosphere.

The decay valve 116 is connected to a valve input port 116 of the decay valve 116 as shown in FIG.
a communicates with the input chamber 111 via the passage 119, the valve output port 116b communicates with the back pressure chamber 117a of the decay diaphragm 117, and the valve exhaust port 116c communicates with the atmosphere. The valve output port 116b communicates (in other words, the input chamber 111 side and the back pressure chamber 11 of the decay diaphragm 117).
7a) and the back pressure chamber 117a is isolated from the atmosphere. When the solenoid 116d of the decay valve 116 is energized and the plunger 116e is moved upward in the drawing, the valve input port 116a and the valve output port 116b are shut off, and the valve output port 116 is closed.
b and the valve exhaust port 116c are communicated with each other.
1 and the back pressure chamber 117a of the decay diaphragm 117 are shut off, and the back pressure chamber 117a is connected to the valve exhaust port 116c.
To the atmosphere side via

The operation of the brake pressure control device according to the above configuration will be described. When the brake pedal 103 is depressed, the brake valve 102 opens, and air corresponding to the depression force of the brake pedal 103 is supplied from the air tank 101 to the air control valve 100 via the relay valve 106. The air pressure flowing into the input chamber 111 of the air control valve 100 acts on the hold diaphragm 115, and moves the hold diaphragm 115 to the right in the drawing against the urging force of the return spring 115b to move the input chamber 1
11 and the output chamber 112 are communicated. The air pressure flows to the air master cylinder 104 through the opened flow path, and operates the brake cylinder 105 to operate the brake similarly to the conventional brake pressure control device.

At this time, the air pressure acts on the decay diaphragm 117 from the output chamber 112 side, but the back pressure chamber 117a of the decay diaphragm 117 has the input chamber 111 → the passage 119 → the valve input port 1 of the decay valve 116.
16a → input chamber 11 via valve output port 116b
Since the air pressure on the first side is acting, the decay diaphragm 117 is not opened by the air pressure from the air master cylinder 4 side.

When the brake pedal is released, the pressure on the brake valve side becomes atmospheric pressure.
The hold diaphragm 115 is opened by the air pressure from the fourth side, and the air pressure is released from the brake valve to the atmosphere via the input chamber 111, and the brake is released. At this time, on the decay diaphragm 117 side, since the air pressure is acting on the back pressure chamber 117a of the decay diaphragm just before the end of the decompression, the air master cylinder 104 and the exhaust chamber 113 side are shut off by the decay diaphragm 117. ing. Immediately before the end of decompression, when the air pressure in the back pressure chamber 117a of the decay diaphragm 117 becomes atmospheric pressure via the valve output port 116b of the decay valve 116 → the valve input port 116a → the passage 119 → the input chamber 111 → the brake valve. Then, the decay diaphragm is pushed open by the air pressure of the air master cylinder 4, and the air pressure is released from the exhaust chamber 113 to the atmosphere via the decay diaphragm side.

[At the time of anti-lock operation] During the operation of the brake, the anti-lock control is started, and when a command to hold the brake pressure is issued, the solenoid 114 of the hold valve 114 is operated.
d, the plunger 114e moves downward in the figure, and the valve input port 114a of the hold valve 114
And the valve output port 114b are communicated with each other.
01 acts on the back pressure chamber 115a of the hold diaphragm 115, presses the hold diaphragm 115 to cut off the communication between the input chamber 111 and the output chamber 112, and the air pressure on the brake device side is the air pressure at that time. Will be retained.

When a brake pressure reducing command is issued, the solenoids of the hold valve 114 and the decay valve 116 are energized, and the plungers 114e and 116e are operated. On the hold valve 114 side, the valve input port 114a and the valve output port 114b communicate with each other. On the decay valve 116 side, a valve output port 116b and a valve exhaust port 116c communicate with each other, and the hold diaphragm 11
5, the air pressure acts on the back pressure chamber 115a, and the air pressure is released on the back pressure chamber 117a side of the decay diaphragm 117. Therefore, the air pressure on the air master cylinder 104 side pushes the decay diaphragm 117 open to open the exhaust chamber. The air is exhausted from 113 to the atmosphere, and the brake pressure is reduced. The pressurization during the antilock control is the same as that for the normal brake.

[0015]

However, in the brake device having the above-described structure, when the brake is shifted from the brake operation state to the brake release state, the air pressure on the air master cylinder side is controlled by the hold diaphragm in the air control valve and the air control valve. Through the long piping path that connects the air control valve and the brake valve, and is released to the atmosphere from the exhaust port of the brake valve, so the path for releasing the air pressure when the brake is released is long. In addition, there is a problem that the air master cylinder cannot be quickly depressurized (brake released) due to a fluid friction resistance in the piping. In other words, there is a limit in improving the responsiveness because the piping path when the brake is released is too long.

Therefore, according to the present invention, a one-way throttle valve is provided in a flow path connecting the brake valve and the hold diaphragm, and an air pressure difference is generated in the decay diaphragm by the action of the one-way throttle valve to open the decay diaphragm. The air pressure from the air master cylinder can be released immediately to the atmosphere via the decay diaphragm → exhaust chamber, the path for releasing the air pressure when the brake is released is shortened, and the air master cylinder is quickly depressurized (brake An air control valve capable of performing (opening) is provided to solve the above problem. Also, a return valve is provided near the input chamber of the air control valve on the upstream side of the one-way throttle valve, and when the brake is released, this return valve is operated by the air pressure of the decay diaphragm back pressure chamber to reduce the air pressure on the back pressure chamber side. By reducing the pressure, an air pressure difference is generated in the decay diaphragm 17, and the decay diaphragm can be opened so that the air pressure in the air master cylinder can be immediately released to the atmosphere. In this case, the air pressure at the time of release is also released. Path can be shortened. Further, the influence of the throttle at the input port portion of the decay valve can be reduced, whereby a small decay valve can be adopted, and the overall configuration of the air control valve can be reduced in size.

[0017]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a means for solving the problems which is arranged between a brake valve and an air master cylinder which applies a brake to wheels by the action of air pressure fed from the brake valve. An air control valve that selectively communicates the air pressure fed from the brake valve to the air master cylinder or reduces the pressure of the communicated air pressure. A one-way throttle that has a hold diaphragm and a decay diaphragm for selectively communicating and closing the same, and that exerts a throttle effect when air flows from the hold diaphragm side to the brake valve side in a flow path communicating from the brake valve to the hold diaphragm. With a valve, when the brake is released, The one-way throttle valve generates an air pressure difference in the decay diaphragm to open the decay diaphragm, and the air pressure on the air master cylinder side can be released to the atmosphere from the exhaust chamber in the air control valve via the decay diaphragm. An air control valve characterized by the following.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an air control valve according to an embodiment of the present invention. It should be noted that the present invention is characterized by the configuration of the air control valve, and the configuration of the brake system is not different from the conventional one. Therefore, the following description will focus on the air control valve.

Referring to FIG.
Is an input port 1 communicating with the brake valve 2 in the body
1, an output port 12 communicating with an air master cylinder (air master) 4 side, and an exhaust port 13 for releasing air pressure to atmospheric pressure through an exhaust valve 13a.
As shown, a hold valve 14, a hold diaphragm 15, a decay valve 1
6. A decay diaphragm 17 is provided. The input port 11 is connected to the valve storage chamber 20 and the back pressure chamber 17 a of the decay diaphragm through the hole 21 of the valve storage chamber 20.
Further, it is connected to the output chamber 12 via the one-way throttle valve 25 and the hold diaphragm 15, and further to the valve input port 16 a of the decay valve 16 via the flow path 26. The output chamber 12 is a decay diaphragm 1
7 and communicate with the exhaust chamber 13.

The hold valve 14 has a valve input port 14a, a valve output port 14b, and a valve exhaust port 14c, like the conventional hold valve.
A return spring 14k, a solenoid 14d, and a plunger 14e for shutting off communication between the respective ports are arranged in the hold valve 14. The plunger 14e is provided with flow passage blocking members 14f and 14g at both ends, and normally moves downward by the urging force of the return spring 14k to shut off the valve input port 14a and the valve output port 14b by the flow passage blocking member 14f. The valve output port 14b communicates with the valve exhaust port 14c.

The valve input port 1 of the hold valve 14
4a is disposed so as to communicate with the valve storage chamber 20 via the one-way throttle valve 25, the valve output port 14b is communicated with the back pressure chamber 15a of the hold diaphragm 15, and the valve exhaust port 14c is communicated with the exhaust chamber 13; The one-way throttle valve 25 and the back pressure chamber 15a are shut off,
The back pressure chamber 15a and the exhaust chamber 13 are in communication. When the solenoid 14d is energized, the plunger 14e moves upward from the state shown in the drawing against the urging force of the return spring 14k, connects the valve input port 14a and the valve output port 14b, and opens the valve by the flow path blocking member 14g. The output port 14b and the valve exhaust port 14c are shut off. The hold diaphragm 15 is formed of an elastic body, and is normally urged by a return spring 15b disposed on the back pressure chamber 15a side in a direction to close the communication between the input chamber 11 and the output chamber 12.

The decay valve 16 has a valve input port 16a, a valve output port 16b, and a valve exhaust port 16c. A plunger 16e for disconnecting and communicating with each port is disposed in the decay valve 16. The plunger 16e includes the flow path blocking members 16f and 16g.
Are provided at both ends, and the plunger 16e is normally urged downward in the figure by the return spring 16k to shut off the valve input port 16a and the valve discharge port 16c by the flow path shutoff member 16g, and to close the valve output port 16b. The valve discharge port 16c is shut off, and the valve input port 16a and the valve output port 16b communicate. When the solenoid 16d is energized, the plunger 16e moves upward from the state shown in the figure, shuts off the valve input port 16a and the valve output port 16b by the flow path shutoff member 16f, and connects the valve output port 16b and the valve exhaust port 16c. To communicate.

The valve input port 16a of the decay valve 16 having the above-described structure is connected to the valve storage chamber 20 through the flow path 26.
The valve output port 16b is connected to the decay diaphragm 1
7, the valve exhaust port 16c communicates with the exhaust chamber 13 and, when not in operation, communicates the valve input port 16a with the valve output port 16b (in other words, the input chamber 11 side and the decay diaphragm 17 of the decay diaphragm 17). Back pressure chamber 1
7a) and shuts off the back pressure chamber 17a from the exhaust chamber 13. When the solenoid 16d of the decay valve 16 is energized and the plunger 16e is moved upward in the drawing, the valve housing chamber 20 and the back pressure chamber 17a of the decay diaphragm 17 are shut off, and the back pressure chamber 17a is Communicate with The decay diaphragm 17 is formed of an elastic body, and is elastically deformed in a direction in which communication between the output chamber 12 and the exhaust chamber 13 is always closed.

A return valve 22 is provided in the valve storage chamber 20.
Is slidably housed, and the valve housing chamber 20 is formed through a hole 21 in the back pressure chamber 17 of the decay diaphragm 17.
a. The return valve 22 has a hat-shaped cross section as shown in the figure. A seal member 24 for sealing the hole 21 is provided at the bottom thereof, and an appropriate communication hole 23 is formed around the return valve 22. The one-way throttle valve 25 has a throttle channel formed in the center thereof, and a return spring 25a.
Is urged downward in the figure. The one-way throttle valve 25 is configured to exhibit the throttle effect only when the air pressure flows from the hold diaphragm side to the brake valve side, and does not exhibit the throttle effect in the opposite case.

The operation of the air control valve according to the above configuration will be described. [During brake operation] When the brake pedal is depressed, the brake valve opens, and air according to the depression force of the brake pedal is supplied from the air tank to the air control valve 10. The air pressure that has flowed into the input chamber 11 of the air control valve 10 acts on the one-way throttle valve 25 from a hole 23 formed in the return valve 22 in the valve storage chamber 20, and causes the one-way throttle valve 25 to act on the biasing force of the return spring 25a. It moves upward in the drawing to act on the hold diaphragm 15. Hold diaphragm 15
Then, the diaphragm 15 is moved rightward in the drawing against the urging force of the return spring 15b, and the input chamber 11 and the output chamber 1 are moved.
2 is communicated via a one-way throttle valve 25. The air pressure flows from the opened output chamber 12 to the air master cylinder, and operates the brake cylinder to operate the brake in the same manner as in the conventional brake system.

At this time, the air pressure also acts on the decay diaphragm 17 from the output chamber 12 side. The back pressure chamber 17a of the decay diaphragm 17 has a hole formed in the input chamber 11 → the return valve 22 in the valve storage chamber 20. 23 → Channel 2
6 → the air pressure on the input chamber 11 side acts via the valve input port 16a → the valve output port 16b of the decay valve 16, so that the decay diaphragm 17 does not open due to the air pressure from the air master cylinder side.

[Brake pedal release] When the brake pedal is released, the brake valve side becomes atmospheric pressure.
The valve storage chamber 20 is also at atmospheric pressure. At this time, the air pressure on the back pressure chamber 17a side of the decay diaphragm 17 flows through the output port 16b → the input port 16a → the flow path 26 of the decay valve 16 to the valve storage chamber 20 side, but due to the throttle effect of the input port 16a. , Not open to the atmosphere at once,
Residual pressure is generated on the back pressure chamber side. The high-pressure air on the side of the air master cylinder opens the hold diaphragm and flows toward the one-way throttle valve 25, but due to the effect of the one-way throttle valve 25, an air pressure difference is also generated around the one-way throttle valve 25.

In this state, the residual pressure on the decay diaphragm 17 acts on the return valve 22 through the hole 21 to move the return valve 22 to the left as shown in FIG. The air pressure on the back pressure chamber 17a side is reduced to the atmospheric pressure at a stroke via the hole 21 → the hole 23 of the return valve, and an air pressure difference is generated in the decay diaphragm 17, which moves the decay diaphragm 17 to output. Chamber 12 and exhaust chamber 13
And the air pressure in the air master cylinder is released at a stretch via the decay diaphragm 17, and the brake is released. Thus, this air control valve 1
In the case of 0, the air pressure at the time of releasing the brake can be discharged from the exhaust chamber 13 via the decay diaphragm 17, so that the path for releasing the air pressure can be shortened, and the air master cylinder can be quickly depressurized (brake release).

When a large-sized decay valve 16 is used and the flow area of the input port 16a of the decay valve 16 is large and does not serve as a throttle (ie, the residual pressure in the back pressure chamber 17a of the decay diaphragm 17 is decayed). The return valve 22 is unnecessary when the exhaust gas is immediately discharged to the valve storage chamber 20 through the output port 16b and the input port 16a of the valve 16 and no residual pressure is generated in the back pressure chamber. An air pressure difference is generated in the decay diaphragm 17, and the output chamber 12 and the exhaust chamber 13 communicate with each other to release the air pressure in the air master cylinder through the decay valve 17 at once, as described above.
The brake can be released.

[At the time of anti-lock operation] At the time of the brake operation, the anti-lock control is started, and when a command for holding the brake pressure is issued, the solenoid 14d of the hold valve 14 is energized, the plunger 14e is operated, and the valve of the hold valve 14 Input port 14a and valve output port 14
b, the air pressure from the air tank acts on the back pressure chamber 15a of the hold diaphragm 15, the communication between the input chamber 11 and the output chamber 12 is cut off by the hold diaphragm 15, and the air pressure on the brake device side is reduced to the air pressure at that time. Hold with pressure.

When the brake pressure reducing command is issued, the solenoids of the hold valve 14 and the decay valve 16 are energized to operate the plungers 14e and 16e, as shown in FIG.
On the hold valve 14 side, a valve input port 14a and a valve output port 14b are communicated, on the decay valve 16 side, a valve output port 16b and a valve exhaust port 16c are communicated, and air pressure is supplied to a back pressure chamber 15a of the hold diaphragm 15. Acts, decay diaphragm 1
Since the air pressure on the side of the back pressure chamber 17a of 7 is released, the air pressure on the brake device side is exhausted from the exhaust chamber 13 via the decay diaphragm 17, and the brake pressure is reduced. The pressurization during the antilock control is the same as that for the normal brake.

In this embodiment, since the one-way throttle valve and the return valve are arranged in the air control valve, the entire valve can be made compact. Further, since the return valve is provided, the influence of the throttle at the input port portion of the decay valve can be reduced, whereby a small decay valve can be employed, and the overall configuration of the air control valve can be downsized. Further, the return valve only needs to be able to control the amount of air on the back pressure chamber side of the decay diaphragm, so that the return valve can be downsized, and any form can be used as long as it has such a function.

[0033]

As described above in detail, according to the present invention, when the brake is released, an air pressure difference is generated in the decay diaphragm 17 by the action of the one-way throttle valve provided in the flow passage communicating with the brake valve. By opening the decay diaphragm to release the air pressure in the air master cylinder to the atmosphere immediately, the path for releasing the air pressure when the brake is released can be shortened, and the air master cylinder can be quickly depressurized (brake release). It can be carried out. Also, a return valve is provided near the input chamber of the air control valve on the upstream side of the one-way throttle valve, and when the brake is released, this return valve is operated by the air pressure of the decay diaphragm back pressure chamber to reduce the air pressure on the back pressure chamber side. By reducing the pressure, an air pressure difference is generated in the decay diaphragm 17, and the decay diaphragm can be opened so that the air pressure in the air master cylinder can be immediately released to the atmosphere. In this case, the air pressure at the time of release is also released. Path can be shortened. Also,
By arranging the return valve, the effect of the throttle at the input port of the decay valve can be reduced, which allows the use of a small decay valve and the overall configuration of the air control valve can be reduced in size. Can play.

[Brief description of the drawings]

FIG. 1 is a sectional view of the present air control valve.

FIG. 2 is a sectional view showing a state of the air control valve when a brake is released.

FIG. 3 is a sectional view showing a state of the air control valve during antilock control.

FIG. 4 is a cross-sectional view of a conventional air control valve disposed in a brake system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Air control valve 11 Input room 12 Output room 13 Exhaust room 14 Hold valve 15 Hold diaphragm 16 Decay valve 17 Decay diaphragm 20 Valve storage room 21 Hole 22 Return valve 23 Hole provided in return valve 24 Seal material 25 One-way throttle valve

Claims (2)

[Claims] 1. A brake valve, which is disposed between a brake valve and an air master cylinder for applying a brake to a wheel by the action of air pressure fed from the brake valve, wherein the air pressure fed from the brake valve is transmitted to the air master cylinder. In an air control valve 10 selectively communicating with a master cylinder or reducing the pressure of an air pressure communicated with the master cylinder, the air control valve is provided with a hold diaphragm 15 and a decay diaphragm for selectively communicating and closing the air. And a one-way throttle valve 25 that exerts a throttle effect when air flows from the hold diaphragm side to the brake valve side in a flow path communicating with the hold diaphragm 15 from the brake valve. For the action of valve 25 The air is characterized in that an air pressure difference is generated in the decay diaphragm 17 to open the decay diaphragm, and the air pressure on the air master cylinder side can be released to the atmosphere from the exhaust chamber in the air control valve through the decay diaphragm. Control valve. 2. A return valve 22 is arranged on the brake valve side of the one-way throttle valve 25. When the brake is released, the air pressure on the back pressure chamber 17a side of the decay diaphragm 17 is discharged to the atmosphere via the return valve 22. Then, an air pressure difference is generated in the decay diaphragm 17 to open the decay diaphragm 17, and the air pressure on the air master cylinder side can be released to the atmosphere from the exhaust chamber in the air control valve via the decay diaphragm 17. The air control valve according to claim 1, wherein