JP3233815B2 - Brake pressure control valve device for air brake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air brake system provided in a vehicle such as a truck or a bus, which is equipped for brake control such as anti-skid control or traction control, and a brake actuator based on the rotation state of wheels. The present invention relates to a brake pressure control valve device for reducing, maintaining, or increasing the pressure supplied to a vehicle.

[0002]

BACKGROUND OF THE INVENTION Generally, a brake pressure control valve device is located between a brake valve and a brake actuator. As one of such brake pressure control valve devices, provided between an inlet connected to a brake valve and an outlet connected to a brake actuator, and urged to a valve closing position by receiving pilot pressure, When the pilot pressure disappears, it is provided between the holding valve that opens by receiving the pressure on the inlet side or the outlet side and the exhaust port that is connected to the atmosphere, and is closed by receiving the pilot pressure. From the exhaust valve that opens when receiving the pressure on the outlet side due to the disappearance of the pilot pressure and the position where the pilot pressure chamber of the holding valve communicates with the exhaust port based on an external brake holding signal. A first control valve that switches to a position for supplying pilot pressure to the pilot pressure chamber, and a pilot valve for the exhaust valve based on an external brake release signal. From a position for supplying the pilot pressure to the chamber are provided with a second control valve switched to the position for communicating the pilot pressure chamber to the exhaust port. Normally, the pilot pressure supplied to each pilot pressure chamber is a brake pressure introduced from a brake valve through an inlet. Then, the brake control such as the anti-skid control or the traction control is performed by the operation of the holding valve and the exhaust valve according to the switching of the first and second control valves.

By the way, in a state where the brake operation is released and released in a normal state, the pilot pressure chamber of the holding valve is in a state of being connected to the exhaust port through the first control valve. The pilot pressure chamber of the exhaust valve is in a state where the pilot pressure is supplied in response to the brake pressure being sent from the brake valve through the second control valve. Under these conditions, during normal brake operation, the brake pressure (air) introduced inside from the brake valve through the inlet
Supplies the pilot pressure to the pilot pressure chamber of the exhaust valve to urge the exhaust valve to the closed position, opens the holding valve by the pressure, and sends the holding valve through the outlet to the brake actuator. When the brake is released, the air supplied to the brake actuator flows back to the inlet through the holding valve opened from the outlet, and is discharged to the atmosphere from the brake valve. On the other hand, the pilot pressure to the pilot pressure chamber of the exhaust valve disappears with the release of the brake, so part of the air flowing backward from the outlet side is opened to the exhaust valve and discharged to the atmosphere from the exhaust port. Will be.

[0004]

Since such a brake pressure control valve device is mounted on a portion of the vehicle that is exposed to the outside near the axle, such as a vehicle body frame, the vehicle can be used in snowy or cold regions. When used, snow and ice may adhere to the exhaust port of the brake pressure control valve device and freeze, blocking the exhaust port. The blockage of the exhaust port occurs, for example, when snow completely blocks the opening of the exhaust port. In addition, in many cases, a check valve is provided at the exhaust port to prevent foreign substances from entering from outside. A rubber plate-shaped valve is used as the check valve. When the valve freezes and loses the valve function, the exhaust port is blocked. When such an exhaust port is blocked, air to be exhausted to the atmosphere through the exhaust port is not exhausted.

[0005] When the brake pressure control valve device is inactive, the first control valve is in a position to communicate the pilot pressure chamber of the holding valve with the exhaust port. Therefore, when the exhaust port is blocked in such a state, particularly when the brake is released in which the air flows out to the exhaust port side, the air to be exhausted to the outside from the exhaust port is not exhausted, and the exhaust port and the third port are not exhausted. It flows into the pilot pressure chamber of the holding valve through the communication passage between the control valve and the control valve. Then, such air is confined in a space from the exhaust port to the pilot pressure chamber of the holding valve.
The air sealed in the pilot pressure chamber of the holding valve acts to increase the closing force of the holding valve. Therefore, even if the pressure on the inlet side is released, the pressure on the outlet side is not released by an amount corresponding to the increased urging force, and a residual pressure is generated in the brake actuator. By the subsequent repetition of the brake operation-release, the pressure of the air trapped in the space from the exhaust port to the pilot pressure chamber of the holding valve increases, and the residual pressure on the brake actuator side also increases accordingly. Such residual pressure on the brake actuator side causes a problem of rubbing of the brake.

[0006]

[Related Art] In the aforementioned brake pressure control valve device,
In order to prevent the generation of residual pressure that causes the brake to be rubbed on the brake actuator side, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-256555, a check valve that allows only the flow of air from the outlet side to the inlet side is provided in a passage formed in parallel with the holding valve, or JP-A-3-292242. As shown in (1), a non-return valve is provided that bypasses the holding valve and the exhaust valve and directly connects the inlet side and the outlet side, and allows only air flow from the outlet side to the inlet side in the pipeline. It is known to provide a valve.

[0007] However, even in the means disclosed in these publications in which measures are taken to prevent the generation of residual pressure in the brake actuator, one of the air supplied to the brake actuator is usually supplied with the release of the brake. The part still flows to the exhaust port side through the outlet and the exhaust valve. Therefore, when the exhaust port is blocked as described above, air to be exhausted to the outside is sealed in the space from the exhaust port to the pilot pressure chamber of the holding valve, and the holding valve is closed by the air pressure. The disadvantage of being biased to the position is not eliminated.

[0008] In the above-mentioned publication, the pressure of the air supplied from the brake valve through the inlet at the start of the normal brake operation is changed from the exhaust port due to the exhaust port blockage to the pilot pressure chamber of the holding valve. The holding valve cannot be opened until the pressure rises beyond the containment pressure in the space leading to. Accordingly, the supply of pressure to the brake actuator through the holding valve and the outlet is delayed by that amount, and a problem arises in that the actual startup of the brake operation is delayed with respect to the brake operation.

[0009]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a technique capable of preventing both the generation of residual pressure on the brake actuator side and a delay in the rise of the brake operation due to the blockage of the exhaust port. And

[0010]

As a means for solving the problems, the present invention is provided between an inlet connected to a brake valve and an outlet connected to a brake actuator,
A holding valve that is urged to the valve closing position by receiving the pilot pressure, and opens by receiving the pressure on the inlet side or the outlet side when the pilot pressure is lost, and an exhaust port that is connected to the outlet and the atmosphere. Between the exhaust valve and the exhaust valve, which is urged to the closed position by receiving the pilot pressure and opens by receiving the pressure on the outlet side due to the disappearance of the pilot pressure. A first control valve that switches from a position in which the pilot pressure chamber of the holding valve communicates with the exhaust port to a position that supplies pilot pressure to the pilot pressure chamber;
A second control valve that switches from a position that supplies pilot pressure to the pilot pressure chamber of the exhaust valve to a position that connects the pilot pressure chamber to the exhaust port based on a brake release signal from outside. In the brake pressure control valve device for an air brake, there is a passage communicating the pilot pressure chamber of the holding valve with the exhaust port through the first control valve, and a part of the passage includes the first control valve and the exhaust port. There is a communication passage that communicates with the communication path, and further, there is an auxiliary passage that communicates this communication passage with the entrance side,
In the auxiliary passage, a check valve that normally closes but opens in response to an increase in the internal pressure on the communication passage side and that allows air movement from the communication passage side of the exhaust port toward the inlet is provided. Further, in the housing of the brake pressure control valve device, in addition to the inlet, the outlet, and the exhaust port, a recess that opens to the outside is formed, and the check valve is detachable in the recess from the outside. It is built into.

[0011]

According to the brake pressure control valve device provided with the check valve at the specific position, the air trapped in the space from the exhaust port to the pilot pressure chamber of the holding valve due to the blockage of the exhaust port is reversed. Can be released through a stop valve.
The communication passage between the first control valve and the exhaust port forms a part of a space in which the air in question is contained. Therefore, such an auxiliary passage for communicating the communication passage to the entrance side is also a passage for communicating the space in question to the entrance side. The above-mentioned check valve provided in such an auxiliary passage is opened due to the pressure difference between the pressure of the air trapped in the space and the pressure of the inlet as the pressure on the inlet side is released when the brake is released normally. Is done. In response to the opening of the check valve, the air sealed in the space escapes to the inlet side. The air escaping to the inlet side at this time is exhausted to the outside through another exhaust port provided in a brake valve connected to the inlet, for example.

Moreover, the check valve does not open and close every time the brake is actuated, and is advantageous in terms of durability. In other words, when the exhaust port is not normally clogged, the internal pressure does not increase on the communication passage side, so that the check valve is kept closed. Only when the internal pressure rises. Therefore, such a check valve does not require relatively high durability, and can be small and inexpensive.

[0013]

FIG. 1 is a sectional view showing a schematic configuration of a brake pressure control valve device 10 according to an embodiment of the present invention. The housing of the brake pressure control valve device 10 has an inlet 12 connected to a brake valve B / V, and an outlet 13 connected to a brake actuator (eg, a brake chamber or an air-hydraulic brake booster) B / C, And, it has an exhaust port 14 communicating with the atmosphere.
Usually, the exhaust port 14 is opened downward, and a check valve 44 for preventing intrusion of foreign matter from the outside is provided there.
Is provided.

Inside the housing of the brake pressure control valve device 10, a holding valve 20 and an exhaust valve 30 for brake control are provided. Both the holding valve 20 and the exhaust valve 30 are diaphragm type valves.
The holding valve 20 is located in the middle of the passage connecting the inlet 12 and the outlet 13, and receives the pressure on the inlet 12 or the outlet 13 against the force of a very light spring that pushes the diaphragm in the valve closing direction. The valve is opened. The holding valve 20 includes a pilot pressure chamber 25 that receives a pilot pressure behind the holding valve 20, and is urged to a valve closing position by receiving a pilot pressure from the outside. On the other hand, the exhaust valve 30 is connected to the outlet 1
The valve is located in the middle of the passage connecting the outlet 3 and the exhaust port 14, and is opened by receiving the pressure at the outlet 13 against the force of a very light spring that pushes the diaphragm in the valve closing direction. The exhaust valve 30 includes a pilot pressure chamber 35 that receives a pilot pressure behind the exhaust valve 30, and is urged to the valve closing position by receiving a pilot pressure from the outside. Here, each pilot pressure is a brake pressure introduced from the brake valve B / V through the inlet 12.

A first control valve 52 and a second control valve 53 are provided corresponding to the holding valve 20 and the exhaust valve 30, respectively. These first and second control valves 5
Numerals 2 and 53 are electromagnetic valves of 3 port-2 position. The first control valve 52 is disposed at an intermediate position of the first signal pressure line 21 extending between the inlet 12 and the exhaust port 14. The first control valve 52 is connected to the pilot pressure chamber 25 of the holding valve 20 through the first signal pressure port 21a, and is connected to the exhaust port 14 through the communication passage 21b. When the pilot pressure chamber 25 is not in operation, the pilot pressure chamber 25 is shut off from the inlet side to take a position to communicate with the exhaust port 14, and the pilot pressure chamber 2 is controlled based on a brake holding signal from an external control unit.
5 is switched from the exhaust port 14 to a position communicating with the inlet 12.

[0016] Similarly, the other second control valve 53 also:
The second signal pressure conduit 31 extending between the inlet 12 and the exhaust port 14 is disposed at an intermediate position. The second control valve 53 is connected to the pilot pressure chamber 35 of the exhaust valve 30 through the second signal pressure port 31a, and is connected to the exhaust port 14 through the passage 31b. When not operating, the pilot pressure chamber 3
5 is a position where the pilot pressure chamber 35 is cut off from the exhaust port 14 and communicates with the exhaust port 14 based on a brake release signal from an external control unit. Is switched to.

[0017]

[Table 1]

Table 1 shows the holding valve 20, the exhaust valve 30, and the corresponding control valves 52, 53, respectively.
3 shows individual switching modes. During the operation of the brake, (fill) indicates a state in which air is sent out from the brake valve B / V, and (relaxation) indicates a state in which air in the brake actuator B / C is exhausted. (Hold) indicates a state in which the air in the brake actuators B / C is kept at a constant pressure. In the first control valve and the second control valve, (OFF) indicates a state in which the solenoid coils are not energized, that is, a so-called non-excitation state, and (ON) indicates
Indicates that it is in the excited state. For the holding valve and the exhaust valve, the presence or absence of the pilot pressure in each pilot pressure chamber is determined by (presence or absence), and the open / close state of the valve is determined by (OPEN) or (CLOSE).
Each is shown.

When the brake pressure control valve device 10 is not operated,
Both control valves 52 and 53 are in a non-excited state, one of the first control valves 52 communicates between the exhaust port 14 and the pilot pressure chamber 25 of the holding valve 20, and the other second control valve 53 has an inlet A communication is established between the pilot pressure chamber 35 of the exhaust valve 30 and 12 (FIG. 1 shows such a state). In such a state, normal brake operation-release is performed.

When the control unit determines that the wheels tend to lock (when the brake control by the brake pressure control valve device 10 is required), first,
The control unit issues a brake holding signal to the holding valve 20. Based on this signal, the first control valve 52 is set in an excited state, and the position of the control valve is switched. This switching causes the first control valve 52 to communicate between the inlet 12 and the pilot pressure chamber 25. In response to this, the holding valve 20 receives the pilot pressure in the pilot pressure chamber 25 and is urged to the valve closed state to shut off the inlet 12 side and the outlet 13 side.
In this way, the braking force by the brake actuators B / C is kept constant.

Subsequently, the control unit issues a brake release signal to the exhaust valve 30. Based on this signal, the second control valve 53 is excited, and the position of the control valve is switched. This switching causes the second control valve 53 to communicate between the exhaust port 14 and the pilot pressure chamber 35. Accordingly, the exhaust valve 30 is connected to the pilot pressure chamber 3
The pilot pressure to 5 disappears, the outlet 13 side and the exhaust port 14
The valve is opened due to the pressure difference with the side. In this way, the braking force by the brake actuators B / C is relaxed. Subsequently, the control valves 52 and 53 are switched via the control unit based on the state of the wheels, so that the brake pressure is stored, held, and released repeatedly, and proper brake control is performed.

Now, such a brake pressure control valve device 1
At 0, a check valve 60 located above the exhaust port 14 in FIG. 1 is one of the points of the present invention. The check valve 60 is provided in a passage 31b connecting the second control valve 53 and the exhaust port 14 and a through hole 64 connecting the second signal pressure port 31a. The through hole 64 constitutes a part of an auxiliary passage 66 that connects the communication passage 21b to the inlet 12 side. That is, the passage 31 b extends from the exhaust port 14 to the pilot pressure chamber 25 of the holding valve 20, including the communication path 21 b (part of the first signal pressure pipe 21) connecting the first control valve 52 and the exhaust port 14. It is the part that communicates with the space. The second signal pressure port 31a is a part that communicates with the inlet 12 through the second control valve 53 when not in operation. Therefore, a through hole 64 that connects the passage 31b and the second signal pressure port 31a is provided in a space (or the first control valve 5) from the exhaust port 14 to the pilot pressure chamber 25 of the holding valve 20.
The communication passage 21b) connecting the exhaust port 2 and the exhaust port 14 is connected to the inlet 1
The two sides communicate with each other to form a part of the auxiliary passage 66.
That is, the auxiliary passage 66 also serves as a communication passage between the pilot pressure chamber 35 and the inlet 12 of the exhaust valve 30 via the second control valve 53.

The check valve 60 is provided in the through-hole 64 which constitutes a part of the auxiliary passage 66, and allows the air to move from the communication passage 21b of the exhaust port 14 toward the inlet 12.
Prohibit the reverse flow. Auxiliary passage 66 and check valve 6
Providing 0 at such a position is preferable in terms of simplifying the internal structure of the brake pressure control valve device 10 and reducing its size, since an existing communication path can be used.
However, for example, instead of this auxiliary passage 66, the second
A passage may be provided to directly connect the exhaust port 14 and the inlet 12 by bypassing the control valve 53, and the check valve 60 may be provided in such a passage.

FIGS. 2 and 3 show a more specific configuration of the brake pressure control device 10 whose circuit configuration is shown in FIG. In particular, FIG. 3 is a sectional view taken along line 3-3 in FIG. In FIG. 2, there are an inlet 12 and an outlet 13 extending laterally above the housing. Below the housing, there is an exhaust port 14 opening downward.

The exhaust port 14 is formed at the lower end of a cylindrical portion 41 of the housing extending in the vertical direction, and a check valve 44 is mounted therein. The check valve 44 includes a round plate 44c attached to a lower end of a shaft portion 44a extending coaxially with the cylindrical portion 41, and a rubber disk 44d provided so as to cover the opening of the cylindrical portion 41. . Round plate 44
Above c, an umbrella-shaped baffle 44b surrounding the shaft portion 44a is provided, and the baffle 44b and the round plate 44c are provided with a plurality of holes arranged in the circumferential direction. Usually, the rubber disk 44d is supported by the round plate 44c, and covers the opening of the cylindrical portion 41 and the hole of the round plate 44c to prevent foreign matter from entering the inside thereof. When the internal air is exhausted, the rubber disk 44d warps outward due to the force of the air, and the air is exhausted through the respective holes of the baffle 44b and the round plate 44c.

In FIG. 3, a holding valve 20 and an exhaust valve 30 are arranged on both sides of the housing. A first control valve 52 and a second control valve 53 corresponding to the holding valve 20 and the exhaust valve 30 in FIG.

The through hole 64 forming a part of the auxiliary passage 66 and the check valve 60 provided in the through hole 64
And arranged below the exhaust valve 30. The check valve 60 has a recess 61 opened to the outside of the housing.
And a valve spring 60b for urging the ball valve body 60a in a seating direction thereof, and a spring receiver of the valve spring 60b, the ball valve body 60a being opposed to the valve seat 62 located at the bottom of the recess 61. 61, a plug member 60c externally mounted. The plug member 60c includes a seal member 67 that blocks the inside of the recess 61 from the outside, and a fitting member 68 that prevents the recess 61 from falling out of the recess 61 itself. Such a check valve 60
It is configured to be detachably attached to the recess 61 from the outside, so that workability such as attachment of the check valve 60 is improved. In addition, the recess 61 is provided in an empty space of the conventional device, and effectively utilizes the mounting space. In addition, in FIG.
Of the second signal pressure port 31a extending to the second control valve 53.

In the embodiment shown in the figure, the first and second control valves 52 and 53 for controlling the pilot pressures of the holding valve 20 and the exhaust valve 30 are of an electromagnetic type, that is, a control unit. Are switched by an electric command signal, but other types can also be used. For example, like an air pilot valve,
An example of the switching is performed by receiving a command signal based on pressure. When the first and second control valves are of an electromagnetic type, a mechanism for converting an electric command signal output from the control unit into a pressure signal is not required, so that the configuration of wiring, piping, and the like is simplified. It is also advantageous in terms of responsiveness.

In the embodiment described above, the ball valve 6
Although the check valve 60 including Oa is used and both the valve body and the valve seat are made of metal, at least a portion of the valve body that is attached to and detached from the valve seat may be formed of a rubber member. FIG. 4 shows an example of such another check valve 160. Instead of a single ball valve body 60a, two members, that is, a valve seat 16 are provided.
2 and an annular rubber valve member 160a, which holds and receives the urging force of the valve spring 160b.
0a constitutes a valve body. Holding member 260a
The notch 360a in the outer peripheral portion of the groove is for forming a passage. In the case where a part of the valve body is formed of a rubber member as in the example of FIG. 4, compared with the case where a metal valve body-metal valve seat in the ball valve body 60 a, that is, a so-called metal seal is formed, Although it is necessary to increase the diameter, the valve spring 160b
The necessary and sufficient sealing force can be obtained even if the urging force of the valve is small (the valve opening pressure is set low). . The opening of the recess 161 has a plug member 1 for holding the valve body in the recess 161 of the housing.
60c, and the plug member 160c itself is prevented from falling out of the recess 161 by the annular metal member 168. Here, the shaft member 26 is attached to the plug member 160c.
When the plug member 160c is set in the recess 161, the shaft 260 c protrudes out of the housing from the opening of the recess 161. The protruding shaft 260c facilitates the attachment / detachment work of the check valve 160.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a brake pressure control valve device 10 according to an embodiment of the present invention.

FIG. 2 is a diagram showing a specific configuration of a brake pressure control valve device 10 shown in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a partial sectional view showing another example of the check valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Inlet 13 Outlet 14 Exhaust port 20 Holding valve 21b Communication passage 25 Pilot pressure chamber 30 Exhaust valve 35 Pilot pressure chamber 52 First control valve 53 Second control valve 60 Check valve 64 Through hole 66 Auxiliary passage

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-58546 (JP, A) JP-A-3-292242 (JP, A) JP-A-6-312659 (JP, A) JP-A-7-58 277166 (JP, A) Japanese Utility Model Hei 6-85162 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/46 B60T 15/36

Claims (3)

(57) [Claims] 1. A valve is provided between an inlet connected to a brake valve and an outlet connected to a brake actuator, and is urged to a valve closing position by receiving a pilot pressure. A holding valve that opens by receiving pressure on the side or the outlet side, and is provided between the outlet and an exhaust port that is connected to the atmosphere, and is urged to a valve closing position by receiving pilot pressure, An exhaust valve that opens when receiving the pressure on the outlet side due to the disappearance of the pilot pressure and a pilot pressure from the position where the pilot pressure chamber of the holding valve communicates with the exhaust port based on an external brake holding signal. A first control valve that switches to a position for supplying pilot pressure to the chamber, and a pilot control chamber for the exhaust valve based on a brake release signal from outside. A second pressure control valve for switching the pilot pressure chamber from a position for supplying the lot pressure to a position for communicating the pilot pressure chamber with the exhaust port, wherein the pilot pressure chamber of the holding valve is connected to the second pressure control valve. There is a passage communicating with the exhaust port through one control valve, and as a part of this passage, there is a communication passage communicating between the first control valve and the exhaust port. There is an auxiliary passage which communicates with the inside of the auxiliary passage.In this auxiliary passage, the valve is normally closed, but is opened in accordance with an increase in the internal pressure on the communication passage side, and air movement from the communication passage side of the exhaust port toward the inlet is performed. Equipped with an acceptable check valve
The housing of the brake pressure control valve device has
In addition to the entry, the exit and the exhaust,
An opening recess is formed in which the check valve is externally mounted.
A brake pressure control valve device for an air brake system, wherein the brake pressure control valve device is detachably incorporated from the device. 2. A pilot pressure supplied to each of the pilot pressure chambers of the holding valve and the exhaust valve is used as a brake pressure introduced into the inlet, and each of the first and second control valves is controlled by a pilot pressure. The brake pressure control valve device for an air brake system according to claim 1, wherein a position for supplying a pilot pressure to the chamber is a position where the pilot pressure chamber is shut off from the exhaust port and communicates with the inlet. 3. The auxiliary passage communicates between the communication passage between the first control valve and the exhaust port, and a passage connecting the pilot pressure chamber of the exhaust valve and the second control valve. 2. The brake pressure control valve device for an air brake system according to claim 1, wherein the check valve is located in a portion of the through hole.