JPH0472747B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic brake operating device, particularly an automatic brake having a braking force holding device that can automatically maintain the brake in an operating state when a vehicle is stopped. It relates to an operating device.

[Conventional technology]

Generally, in a vehicle, when the brake pedal is depressed, the brakes are activated and the vehicle is in a braking state, and when the brake pedal is released, the brake operation is released and the vehicle is in a non-braking state. Therefore, when the vehicle is temporarily stopped on a slope, etc., it is usually necessary to operate a separate braking system such as the handbrake, and when starting again, the handbrake must be released while the vehicle is being stopped. , operations that required skill such as operating the accelerator and clutch were required.

In recent years, automatic brake operating devices, i.e., vehicles, have been developed that have a braking force retention device that frees the driver from such complicated operating means and enables safe and easy driving operations. A braking force retention device that automatically maintains the braking state even if the brake pedal is released after the vehicle has come to a stop, and also automatically releases the brake when the vehicle starts, allowing a smooth start. An automatic brake operating device having the following has been disclosed (see, for example, Japanese Patent Laid-Open No. 11719/1983).

In addition, as for the automatic brake operating device having a braking force holding device, as prior art, FIGS. 2 and 3
There are some as shown in Figure A and Figure 3 B. Regarding this, the above brake operating device will be explained with reference to FIGS. 2, 3A, and 3B.

FIG. 2 is a schematic diagram of the system of the brake operating device, in which high-pressure air accumulated in an air tank 2 by an air pump 1 is passed through a brake valve 3 through a conduit 9 to an electromagnetically operated check valve (described later). 5
is supplied to High-pressure air passes through the conduit 10 from the discharge side of the check valve 5 and moves the piston in the hydraulic booster 6. The movement of the piston operates the wheel cylinder 7 and applies braking to the wheel. The high-pressure air in the air tank 2 can pass through the brake valve 3 only when the brake pedal 4 is depressed, and when the brake pedal 4 is released, the discharge side of the brake valve 3 is configured to communicate with the atmosphere. Its configuration is similar to the conventional one. High-pressure air is separately supplied to the electromagnetically operated check valve 5 via a conduit 11, and the electromagnetically operated check valve 5 operates according to the opening and closing of the electromagnetic valve operated by a signal from the control device 8. A passage closing means provided therein is actuated by the high pressure air and is configured to block communication between the conduit 9 and the conduit 10.

Next, details of the electromagnetically operated check valve 5 will be described with reference to FIGS. 3A and 3B.
The electromagnetically operated check valve 5 has a cylinder 21, and a piston 22 is provided inside the cylinder 21. A valve body 24 is attached to the tip of the piston 22 via a pin 23. Piston 22
The locking hole of the pin 23 formed at the tip of the pin 23 and the pin locking hole 25 formed in the valve body 24 are both connected to the pin 23.
Therefore, the valve body 24 is mounted so as to be slightly movable in the axial direction with respect to the piston 22. Further, the valve body 24 is always biased to the right in the figure by a spring 26 provided within the piston 22.

A supply port 28 having a valve seat 27 is formed at the tip of the cylinder 21, and the supply port 28 is connected to the air tank 2 via the aforementioned pipe 9 and brake valve 3 (see FIG. 2). A discharge port 29 is further formed at the tip of the cylinder 21, and the discharge port 29 is connected to the above-mentioned hydraulic booster 6 (see FIG. 2) via a conduit 10. A spring 31 is provided in the pressure chamber 30 formed by the cylinder 21 and the piston 22, and the action of the spring 31 causes the piston 22 and the valve body 22 to
is normally pressed in the direction away from the valve seat 27 (the position shown in FIG. 3A).

A solenoid valve 32 is attached to the rear end of the cylinder 21. The solenoid valve 32 has a solenoid 33 and a plunger 34, and the plunger 34 is connected to a rod 35 extending vertically downward. Two valve chambers 37 and 38 are provided below the rod 35 and communicated with each other by a passage 36, and two opposing valve bodies 39 and 40 are disposed in the two valve chambers 37 and 38. Ru.

The two valve bodies 39 and 40 are connected to the rod 41.
The rods 35 and 41 are integrally connected coaxially via a connecting member 42. A spring 43 is disposed within the valve chamber 38, and due to the action of the spring 43, the plunger 34, the rod 35, the connecting member 42, the valve body 39,
Valve operating member 44 consisting of rod 41 and valve body 40
is normally biased upward, and the valve chamber 38 and passage 36 are closed off by a valve body 40. The valve chamber 37 communicates with an atmospheric chamber 46 at the rear of the piston 22 through a through hole 45 provided in the cylinder 21 , and the passage 36 communicates with an atmospheric chamber 46 at the rear of the piston 22 through an operating air passage 47 . It communicates with room 48. Further, the valve chamber 38 is connected to the high pressure air line 11 (see FIG. 2) via a supply port 49.

The operation of the electromagnetically operated check valve 5 described above is as follows. In a normal state, that is, in a state in which the solenoid valve 32 is not energized, the valve operating member 44 is in the position shown in FIG. 3A. In that position, the valve body 40
Therefore, communication between the valve chamber 40 and the passage 36 is cut off, and the atmospheric chamber 46 and the pressure chamber 48 at the rear of the piston 22 are connected to the atmosphere from the valve chamber 37 through the through hole 45 and the working air passage 47, respectively. It's communicating. Therefore, the piston 22 and the valve body 24 are urged to the most retracted position shown in FIG. 3A by the action of the spring 31.

Accordingly, when the brake pedal 4 is depressed, high-pressure air flows from the pipe 9 through the supply port 28 into the pressure chamber 30, and further flows from the discharge port 29 through the pipe 10 into the hydraulic booster 6. As mentioned above, this causes a braking action. When the brake pedal 4 is released, the conduit 9 is opened to the atmosphere as usual, but the valve body 24 closes the conduit 10, maintaining high pressure air and maintaining braking force.

The functions of the solenoid valve 32, piston 22, and valve body 24 are as follows. The solenoid valve 32 is connected to the control device 8
It is turned on and off by the signal from (see Figure 2). As described above, in the normal state, the solenoid valve 32 is in the OFF state, and therefore the valve operating member 44 is biased to the position shown in FIG. 3A. The control device 8 issues a predetermined signal to turn on the solenoid valve 32 under certain conditions, for example, one second after the vehicle has stopped. In response to the predetermined signal, the solenoid 33 is energized, and the rod 3 of the valve operating member 44 is energized.
5 is moved downward to the state shown in FIG. 3B.

In this state, the valve chamber 37 and the passage 36 are closed by the valve body 39, and the valve chamber 38 and the pressure chamber 48 are closed.
are in communication via the passage 36 and the working air passage 47. As described above, the valve chamber 38 communicates with the high pressure air pipe line 11 (see FIG. 2) via the supply port 49, and therefore, the valve operating member 44 is located at the position shown in FIG. 3B. At this time, high pressure air acts on the pressure chamber 48. As a result, the piston 22 moves to the right in the figure, and the valve body 24 comes into contact with the valve seat 27, cutting off communication between the pipe line 9 and the pressure chamber 30.

First, when the vehicle is running normally, brake pedal 4
The brakes are actuated by pressing the button and sending high-pressure air from a pneumatic source consisting of an air pump 1 and an air tank 2 to a brake actuator section consisting of a hydraulic booster 6 and a wheel cylinder 7 via an electromagnetically operated check valve 5. do. When the vehicle stops in this state, a certain period of time later, the control device 8 issues a signal to turn on the solenoid valve 32. As a result, the high pressure air flows into the pressure chamber 48 and moves the piston 22, causing the valve body 24 to
The communication between the pipe line 9 and the pressure chamber 30 is cut off. Even if the brake pedal 4 is released in this state and the pipe line 9 is communicated with the atmosphere, the pipe line 10 communicating with the brake actuator side is cut off from the atmosphere side by the valve body 24, so the pipe line 9 is connected to the atmosphere. 10 will be maintained in a high pressure state, and the brake will continue to be in an activated state. Even if the brake pedal is released while the vehicle is temporarily stopped on a slope or the like, there is no risk that the vehicle will start moving on its own, and there is no need to necessarily pull the handbrake.

Furthermore, when the accelerator or clutch is operated to prepare the vehicle for starting, the control device 8 senses this and turns off the solenoid valve 32. When the solenoid valve 32 is turned off, the solenoid operated check valve 5 returns to the state shown in FIG. The air is released to the atmosphere, the brakes are released, and the vehicle can start moving. Therefore, it is no longer necessary to operate the accelerator or clutch while loosening the handbrake as in the past.

[Problem that the invention seeks to solve]

Normally, in a vehicle's brake system, when the brakes are activated, a pressure approximately equal to the pressure in the air tank 2 is generated in the hydraulic booster 6 and the pipes 9 and 10, and if this state is maintained for a long time, the brake This causes inconveniences such as seizure on the friction surface and mechanical loss on the sealing surface. Therefore, if the brake operation is to be maintained for a long period of time, the pressure of the hydraulic booster 6, high pressure air, etc. is maintained at a constant value lower than the pressure required for brake operation when the vehicle is running. The means are in place.

In the case shown in FIG. 3A and FIG. Air pressure P2 × effective pressure receiving area S2 on the pressure chamber 30 side of the piston + force f of the spring 31] difference F = F1
- While the piston 22 moves from the position shown in FIG. 3A to the position shown in FIG. At the time when communication is cut off, the pressure on the conduit 10 side is maintained at a pressure value that does not cause problems such as seizure on the brake actuator side. That is, the piston 22 and the valve body 24 function as a kind of pressure regulating valve.

That is, in the electromagnetically operated check valve 5 of the above-described type, the brake pedal 4 is depressed to stop the vehicle, and after a certain period of time, the electromagnetic valve 32 is turned on by a signal from the control device 8, and the flow from the pipe 11 is When high-pressure air flows into the pressure chamber 48, the piston 22 and the valve body 24 remain at the open position shown in FIG. By gradually opening the pressure chamber 30, the pressure P in the pressure chamber 30 gradually decreases, and as the piston 22
moves to the right in the figure, and after a predetermined pressure drop, it finally reaches the position shown in FIG.

However, if the brake pedal 4 is suddenly released while the solenoid valve 32 is on, the pipe line 9 will be instantly released to the atmosphere, and as a result, the pressure chamber 30 and the pipe line 10 will also be instantly released. The brake actuator side, which is released to the atmosphere,
That is, the pressure inside the hydraulic booster 6 decreases rapidly. On the other hand, the piston 22 and the valve body 24 are
The piston 22 and cylinder 21 are required to reach the line blocking position shown in Fig. 3B from the most retracted position shown in Fig. 3A.
This takes a certain amount of time due to the effects of friction between the two.

Therefore, when the brake pedal 4 is suddenly released, there is a sudden pressure drop on the brake actuator side, that is, on the pipe line 10 and the hydraulic booster 6 side, and the time required for the valve body 24 to close. Due to the relationship with time, there is a risk that the pressure in the pipe line 10 and the hydraulic booster 6 will have already fallen below the predetermined pressure by the time the communication between the pipe line 10 and the pipe line 9 is cut off by the valve body 24. It was hot.

In particular, if the brake is pressed strongly when stopping the vehicle on a slope such as a slope, the conduit 10
The pressure value on the brake actuator side may be higher, and in such a case, suddenly releasing the brake pedal 4 tends to cause an unnecessarily pressure drop on the brake actuator side, and the so-called brake This poses a problem because the vehicle may start to move depending on the inclination of the slope and a serious accident may occur.

An object of the present invention is to solve the above-mentioned problems of the automatic brake operating device using the electromagnetically operated check valve, and even when the brake pedal is suddenly released after the vehicle has stopped,
Similar to when you gradually release the brake pedal.
A control system that creates a gradual pressure drop on the brake actuator side and closes the pipeline to prevent the pressure on the brake actuator side from dropping below a predetermined level, thereby maintaining the air pressure on the brake actuator side. An object of the present invention is to provide an automatic brake operating device having a power holding device.

[Means for solving problems]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention provides a system for intervening in a conduit connecting a pneumatic source such as an air pump, an air tank, etc. and a brake actuator comprising a hydraulic booster, wheel cylinder, etc., and for transmitting a signal based on a predetermined condition such as a stop of the vehicle. further comprising a closing means such as a piston/cylinder that closes the conduit and maintains braking force in response to a predetermined signal from the control means, and further between the closing means and the brake actuator. a throttle member provided in the conduit and restricting outflow of air from the conduit prior to closing of the conduit by the closing means in response to the closing operation of the closing means; The present invention relates to an automatic brake operating device having a braking force holding device characterized by having a throttle passage forming a part of a conduit.

Further, in the automatic brake operating device having this braking force holding device, the closing means is configured with an electromagnetically operated check valve.

Further, in the automatic brake operating device having this braking force retention device, the pipe line in the portion where the outflow of air is restricted by the throttle member is composed of an expanded portion and a throttle passage, and the expanded portion is The throttle passage is closed by a throttle member, and the throttle passage is not closed by the throttle member.

Further, in the automatic brake operating device having this braking force holding device, the pipe line in the portion where the outflow of air is restricted by the throttle member is narrowed according to the closing operation of the closing means, so that the air outflow is restricted. This is a constricted passageway that limits the flow of air.

Specifically, the throttle member is provided on the inner wall of the cylinder so as to move with the start of the closing operation of the closing means, and by the movement of the piston within the cylinder, opens a part of the cross section of the conduit and Can be configured to close sections. Further, the throttle passage is formed into a small diameter passage branching from the pipe line,
The restricting member may be configured to close the entire cross section of the conduit. Alternatively, the throttle member may be configured to throttle the pipeline by interposing an electromagnetic throttle valve or the like operated by a piston movement signal in the pipeline.

[Effect]

The automatic brake operating device having a braking force holding device according to the present invention is configured as described above, and after the vehicle has stopped, the brake pedal is suddenly released, thereby causing the brake pedal to be closer to the pneumatic source than the conduit closing means. Even if the pressure in the conduit decreases rapidly, the closing action of the conduit closing means that occurs immediately after the brake pedal is released causes the throttling member to work, thereby reducing the effectiveness of the conduit between the closing means and the brake actuator. Due to the instantaneous narrowing of the cross-sectional area, there is no sudden pressure drop on the brake actuator side, and therefore the brake actuator side is able to keep the brakes in the operating state for a long time. An appropriate predetermined pressure will be maintained.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic brake operating device having a braking force holding device according to the present invention will be described in detail below with reference to the drawings. Note that this invention does not include the structure of the conduit closing means interposed in the conduit connecting the pneumatic pressure source and the brake actuator and the constriction means interposed in the conduit between the brake actuators.
The other configurations are the same as the automatic brake operating device having the above-mentioned braking force holding device described above with reference to FIGS. 2, 3A, and 3B. Therefore, in the following explanation, the "diaphragm means" will be particularly explained, and the explanation of the same structure will be omitted. Also, in the embodiment described below, except for the part related to the "throttling means", FIG.
Since it is the same as that shown in Figures 3A and 3B, the same reference numbers are used in Figures 1A and 1B for the same parts as in Figures 3A and 3B. The detailed explanation thereof will be omitted.

Figure 1A corresponds to Figure 3A,
The piston 22 and the valve body 24 are shown in their most retracted positions. Also, FIG. 1B corresponds to FIG. 3B, and the solenoid valve 32 is turned on,
A state is shown in which communication between the air pressure source side pipe line 9 and the brake actuator side pipe line 10 is cut off by the valve body 24. The "diaphragm means" in this embodiment is constructed as follows. That is, the conduit 10
Between the discharge port 101 connected to the pressure chamber 30,
A throttle passage 102 with a small diameter is provided, and the open end of the discharge port 101 on the pressure chamber 30 side is an expanded portion 103 that expands in the circumferential direction [see FIG. It is formed narrower than the end on the connection side with the conduit 10.

Further, the large diameter portion 110 of the piston has a large diameter portion 1
A ring-shaped member 111 having the same diameter as the outer diameter of 10
weld. The axial width of the ring-shaped member 111 is
When the piston 22 is in the most retracted position shown in FIG.
12 and the rear edge in the axial direction, that is, the left edge of the expanded portion 103 of the discharge port 101, are the same, or are located rearward than the edge, and the tip of the ring-shaped member 111 when the valve is closed as shown in FIG. The width is such that the portion 112 does not close the throttle passage 102.

The operation of the automatic brake operating device having the braking force holding device according to the present invention is as follows. In the normal state shown in FIG. 1A, that is, in the state in which the solenoid valve 32 is off, its operation is similar to the conventional one described above. When the brake pedal 4 is suddenly released while the solenoid valve 32 is in operation, the pressure in the pipe line 9 and the pressure chamber 30 drops rapidly. However, immediately after the piston 22 starts moving due to the pressure drop, the discharge port 101 on the brake actuator side
The expanded portion 103 is instantly closed by the movement of the ring-shaped member 111, and as a result, the throttle passage 10
The pipe line 10 and the pressure chamber 30, that is, the atmosphere side, communicate only through the pressure chamber 2.

Therefore, for a predetermined period of time required for the valve body 24 to come into contact with the valve seat 27 and cut off the communication between the pressure chamber 30 and the pipe line 9, the brake actuator is operated only by the throttle passage 102. The conduit 10 on the actuator side will communicate with the atmosphere, and even if the conduit 9 is suddenly opened to the atmosphere, the pressure drop on the brake actuator side will be maintained at a constant value. By appropriately determining the diameter of the throttle passage 102, the moving distance of the valve body 24, and the width of the ring-shaped member 111, the amount of pressure drop can be determined to a predetermined value.

FIG. 4A and FIG. 4B show other examples of the expanded portion 203 of the discharge port 101 and the throttle passage 202.
In this example, the expanded portion 203 and the throttle passage 20
2 is formed as one continuous opening. That is, the throttle passage 202 is formed as a narrow notch in the axial direction from the expanded portion 203 of the discharge port 101. In this example, the ring-shaped member 111
When the solenoid valve 32 is off, the tip 112 is at the position L ₁ , and when the solenoid valve 32 is on and the piston 22 moves to the right, it is at the position L ₂ .
That is, it is designed so that only a portion of the throttle passage 202 is not closed by the ring-shaped member 111 and is in communication with the pressure chamber 30 .

FIG. 5A and FIG. 5B show still other examples of the expanded portion 303 of the discharge port 101 and the throttle passage 302. As shown in FIG. 5B, the expanded portion 303 in this example has a triangular shape, and the corner portion at the tip functions as the throttle passage 302. Note that the symbols L ₁ and L ₂ refer to the tip 1 of the ring-shaped member 111, as explained in FIGS. 4A and 4B.
12 positions, and their explanations will be omitted.

Figure 4 A and Figure 4 B and Figure 5 A and Figure 5
It is clear that the "diaphragm means" having the configuration shown in FIG. 1B has the same effects as those shown in FIGS.

Although not shown, the discharge port 1 of the cylinder 21
Instead of providing the throttle passages 102, 202, 302 on the side of 01, small holes are provided on the side of the ring-shaped member 111,
It is also possible to form a notch or the like so that the small hole or notch acts as a communication portion between the conduit 10 and the pressure chamber 30 when the ring-shaped member 111 closes the discharge port 101 .

Further, in what is shown in FIG. 1, the ring-shaped member 111 and the piston 22 are formed as separate members, but it is of course possible to form them as an integral member.

Furthermore, the throttling means is not limited to means consisting of the ring-shaped member 111 that moves together with the piston 22 and the throttling passage 102, but can also be used to connect the flow path of the conduit between the closing means and the brake actuator with the closing operation of the closing means. It is clear that any type of device that can be used to throttle the conduit can be used. For example, the closing operation of the closing means can be detected by a sensor, and the signal can be used to tighten the restricting means, solenoid valve, etc. provided in the pipe by a predetermined amount. It is also possible to use means for moving it.

〔Effect of the invention〕

The automatic brake operating device having the braking force holding device according to the present invention is configured as described above, and has the following effects. That is, in a conduit connecting a pneumatic source consisting of an air pump, an air tank, etc. and a brake actuator consisting of a hydraulic booster, wheel cylinder, etc., there is a control means that issues a signal in response to a predetermined condition such as when the vehicle stops. A piston that closes the pipe in response to a predetermined signal of
A closing means such as a cylinder is interposed, and a throttle member for restricting the air flow during the closing operation of the closing means is interposed in the conduit between the closing means and the brake actuator. Even if the brake pedal is suddenly released after stopping and the pressure in the conduit on the side of the pneumatic pressure source relative to the closing means drops suddenly, the closing operation of the closing means occurs immediately after the brake pedal is released. As a result, the throttle member acts to instantly narrow down the effective cross-sectional area of the pipe between the pipe closing means and the brake actuator.

Therefore, there is no sudden pressure drop on the brake actuator side, and the closing means is closed while maintaining exactly the predetermined pressure, similar to the state in which the brake pedal is slowly released. That is, the pressure balance function is achieved slowly, and when a predetermined line internal pressure is reached, the closing means completely closes the line.

Therefore, the air pressure in the pipe is maintained on the brake actuator side, ie, the hydraulic booster, air cylinder, etc., at a predetermined pressure that is appropriate for maintaining the brake in an operating state for a long time. . Therefore, even if the vehicle stops on a steep slope, a serious accident such as the vehicle backing up or starting to move will not occur.

[Brief explanation of drawings]

Figures 1A and 1B are cross-sectional views of an electromagnetically operated check valve used in an automatic brake operating device having a braking force holding device according to the present invention, and Figure 1C is a cross-sectional view taken along the arrow line in Figure 1A. , Fig. 2 is a schematic diagram of a system of an automatic brake operating device having a braking force holding device, Fig. 3 A and Fig. 3 B are sectional views showing a check valve in a conventional brake operating device, and Fig. 4 I , FIG. 4B, and FIGS. 5A and 5B are explanatory diagrams showing other examples of the throttling means in the electromagnetically operated check valve used in the automatic brake operation device having the braking force holding device according to the present invention. It is. 1...Air pump (air pressure source), 2...Air tank (air pressure source), 5...Solenoid operated check valve, 6...
Hydraulic booster (brake actuator), 7...Wheel cylinder (brake actuator), 9, 10, 11...Pipe line, 22...
Piston (closing means), 24... Valve body (closing means), 32... Solenoid valve, 44... Valve operating member, 1
02,202,302... Throttle passage, 103,2
03, 303... Expansion part (pipe line), 111... Ring-shaped member (diaphragm member).

Claims (1)

[Scope of Claims] 1. Closing means interposed in a conduit connecting a pneumatic pressure source and a brake actuator and closing said conduit in response to a predetermined signal to maintain braking force, and said closing means. disposed in the conduit between the means and the brake actuator and responsive to the closing operation of the closing means to restrict the outflow of air in the conduit prior to closing of the conduit of the closing means; An automatic brake operating device having a braking force holding device, characterized in that it has a throttle member and a throttle passage that constitutes a part of the pipe that cannot be closed by the throttle member. 2. An automatic brake operating device having a braking force holding device according to claim 1, wherein the closing means is constituted by an electromagnetically operated check valve. 3. The pipe line in the portion where air outflow is restricted by the throttle member is composed of an enlarged part and a throttle passage, the enlarged part is closed by the throttle member, and the throttle passage is closed by the throttle member. An automatic brake operating device having a braking force holding device according to claim 1, characterized in that the braking force holding device is not closed by a member. 4. A patent characterized in that the pipe line in the portion where the outflow of air is restricted by the throttle member is narrowed in accordance with the closing operation of the closing means, thereby forming a throttle passage that restricts the outflow of air. An automatic brake operating device comprising the braking force holding device according to claim 1.