JPH09132133A - Fluid pressure operated check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable holding pressure in brake operating to be changed, to lengthen the life of a wheel cylinder, to simplify a structure, to improve the degree of freedom in the layout, and to reduce cost. SOLUTION: A piston 58 for forming an atmospheric pressure chamber 61 and an output pressure chamber 62 in a cylinder, and to be energized in the direction in which the atmospheric pressure is contracted, and a valve body 52 connected to the piston and placed in the output pressure chamber are provided. The valve body 52 is energized in the direction of a valve seat 65 formed on a fluid passage between an inlet 51a and an outlet 51b, the valve body is normally so arranged as to face the valve seat with the constant distance from the valve seat, an electromagnet 53 for applying energizing force in the direction in which the output pressure chamber 62 is to be contracted to the piston 58 is provided, energizing force to be applied to the piston 58 by the electromagnet 53 is made variable by changing the amount of current to be allowed to flow to a coil 15 of the electromagnet 53, and the amount of current to be allowed to flow to the coil 75 of the electromagnet 53 is controlled by a controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure reverse operation suitable for a brake operation device or the like for preventing a vehicle from retreating against the driver's will when a vehicle starts on a slope having an upward slope. It concerns a stop valve.

[0002]

2. Description of the Related Art As shown in FIG. 5, a brake operating device used for a large vehicle such as a truck towing a trailer is arranged such that compressed air in air tanks 1a and 1b is brake-controlled via respective conduits 2a and 2b. It is supplied to the control valve 3 and the solenoid valve 4. The discharge side of the brake control pressure control valve 3 is connected to a fluid pressure operated check valve 6 via a line 5, and when the brake pedal 3 a of the brake control pressure control valve 3 is depressed, the fluid pressure operated check valve 6 is opened. When the brake pedal 3a is released, the discharge side of the brake control pressure control valve 3 communicates with the atmosphere.

On the other hand, the discharge side of the solenoid valve 4 is connected to a fluid pressure operation check valve 6 through a passage 7, and when the solenoid valve 4 is turned on by a signal from a controller 8, the fluid pressure operation check is stopped. When the signal pressure is supplied to the valve 6 and the solenoid valve 4 is off, the discharge side of the solenoid valve 4 communicates with the atmosphere. Further, the discharge side of the fluid pressure operated check valve 6 is connected to a brake actuator 10 through a pipe 9, and when the brake actuator 10 is driven by the pressure supplied from the fluid pressure operated check valve 6, the wheel cylinder is driven. The hydraulic pressure is supplied to 11 and the brake shoe 12 rotates to operate the brake.

FIG. 6 is a longitudinal sectional view showing an electromagnetic valve and a fluid pressure operated check valve of the brake operating device. The solenoid valve 4
It has a solenoid 14 and a plunger 15, and a rod 16 extending downward in the vertical direction is connected to the plunger 15. Below the rod 16, a pair of upper and lower valve chambers 18a and 18b which communicate with each other in a communication passage 17 are formed, and valve bodies 19a and 19b are arranged in the pair of valve chambers 18a and 18b, respectively. This pair of valve bodies 19a, 19b
Are connected to each other by a rod 20, and the lower valve body 19b
Is connected to the lower end of the rod 20.

When the plunger 15 moves up and down by driving the solenoid 14, a pair of valve seat holes 22a and 22b formed at both upper and lower ends of the communication passage 17 are opened and closed by a pair of valve bodies 19a and 19b. Lower valve body 19b
Is urged upward by a spring 23.

The valve chamber 18b of the solenoid valve 4 communicates with a pressure inlet 26, and the pressure inlet 26 is connected to the air tank 1b via a pipe 2b. Therefore, the valve chamber 18b
Inside, compressed air is always introduced. An intermediate portion of the communication passage 17 communicates with a signal pressure chamber 37 of the fluid pressure operated check valve 6 via a signal pressure port 29. The valve chamber 18 a is communicated with the outside through an annular space communicating with the passage 30 branched from the middle of the passage 31 and a pipe connected thereto at a location not shown, and the fluid pressure operated check valve 6 through the passage 31. It communicates with the atmospheric pressure chamber 38.

[0007] The fluid pressure operated check valve 6 includes a piston 34 disposed in a cylinder 33 and a valve body 36 attached to a front end of the piston 34 by a pin 35.
A signal pressure chamber 37, an atmospheric pressure chamber 38, and an output pressure chamber 39 are formed on both sides of the piston 34, and the piston 34 is attached by a return spring 40 in the output pressure chamber 39 in a direction away from the valve seat 32 on the inlet 42 side. It is being rushed. In addition, the valve body 36
Is biased by the spring 41 in a direction approaching the valve seat 32 on the inlet 42 side, and the pin 35 is inserted into the piston 34 in a loosely fitting manner. Can be moved.

[0008] The inlet 42 of the fluid pressure operated check valve 6 is connected to the brake control pressure control valve 3 via a line 5.
An outlet 44 communicating with the output pressure chamber 39 is connected to the brake actuator 10 via the pipe 9.

The controller 8 receives information on the operating states of the brakes, accelerators, clutches, and the like and the vehicle speed, and turns off the solenoid valve 4 when the vehicle is running and when starting, and turns it on when the vehicle is stopped.

[0010]

In the above-mentioned conventional brake operating device using the fluid pressure operated check valve, the air tank 1b is provided.
The compressed air is constantly introduced into the pipe line 2b on the side, and the air pressure is introduced into the signal pressure chamber 37 of the fluid pressure operation check valve 6 by turning on / off the solenoid valve 4, and the pressure which the piston 34 operates and is maintained is increased. Since it is always constant, if a brake holding force capable of stopping even on a sloping road in a loaded state is ensured, an extra load is applied to the wheel cylinder 11 on a flat road when the vehicle is empty, which shortens the life of the wheel cylinder 11. It was

Further, in addition to the air tank 1a, an air tank 1b for signal pressure and an extra pipe line 2b associated therewith are required, so that not only layout restrictions are imposed but also the valve chambers 18a of the solenoid valve 4 are provided. 18b, valve bodies 19a, 19
Since b, rod 20, etc. are required, there is a drawback that the structure is complicated and the cost is high.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to make the holding pressure of the piston variable so that an unnecessary load is not applied to the wheel cylinder on a flat road when the vehicle is empty. Without shortening the life of
Eliminates the need for an air tank for signal pressure and the associated pipeline
It is an object of the present invention to provide a fluid pressure operated check valve capable of improving layout flexibility and reducing cost.

[0013]

To achieve the above object, the present invention as set forth in claim 1, is a cylinder having an inlet connected to a brake control pressure control valve and an outlet connected to a brake actuator, The inlet is provided with a piston that defines an atmospheric pressure chamber and an output pressure chamber in the cylinder and is urged in a direction in which the atmospheric pressure chamber contracts, and a valve body that is connected to the piston and is in the output pressure chamber. The valve body is biased toward the valve seat formed in the fluid passage between the valve seat and the outlet, and the valve body is normally arranged at a constant distance from the valve seat to face the valve seat. In the fluid pressure operated check valve, an electromagnet that applies an urging force in a direction in which the output pressure chamber is contracted to the piston is provided, and by changing the amount of current flowing through the coil of the electromagnet, the electromagnet applies the piston to the piston. The power is variable It is characterized in. According to a second aspect of the present invention, in the fluid pressure check valve according to the first aspect, the controller controls the amount of current flowing through the coil of the electromagnet.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A fluid pressure operated check valve according to an embodiment of the present invention will be described in detail with reference to the drawings, taking a case where it is applied to a brake operating device as an example. FIG.
FIG. 2 is a schematic configuration diagram of a brake operating device using a fluid pressure operated check valve according to an embodiment of the present invention, in which the same parts as those in the related art are designated by the same reference numerals, and FIG. It is a longitudinal section showing a fluid pressure operation check valve concerning a form.

In this brake operating device, a brake valve is connected to an inlet 51a and a brake actuator 10 is connected to an outlet 51b of a fluid pressure check valve 50, and an air tank 1a is connected to the brake valve 3 so that the air tank 1a is connected to the brake valve 3. A compressed air is supplied, and a wheel cylinder 11 is connected to the brake actuator 10.

The fluid pressure operation check valve 50 used in this brake operating device has an output pressure chamber 6 which is applied to the piston 58 by the electromagnet 53 when the vehicle is in a brake operating state.
2 applies an urging force in the direction of contraction, and the controller 54 which takes in information such as the loading state and the inclination angle of the road surface by the sensor controls and changes the amount of current flowing through the coil 75 of the electromagnet 53 to change the electromagnet 53. The biasing force is variable, and the optimum braking force can be applied and held.

The fluid pressure operation check valve 50 has a cylinder 51 having a downward inlet 51a and a lateral outlet 51b, and a slidable piston 58 sealed in an annular seal member 57 in the cylinder 51. A valve element 52 is connected to the piston 58 with a pin 59, and the piston 58 defines an atmospheric pressure chamber 61 and an output pressure chamber 62.

The cylinder 51 has a valve seat 65 formed at a position facing the output pressure chamber 62 at the back of the inlet 51a, and outputs a compression spring 66 for urging the piston 58 in a direction in which the atmospheric pressure chamber 61 contracts. It is accommodated in the chamber 62. Further, the cylinder 51 is integrally provided with an outward flange 67 at an upper end, and an outward flange 72 of a shell 71 that accommodates the electromagnet 53 is overlapped on the flange 67, and the electromagnet 53 is formed using a plurality of bolts 68 and nuts 69. It is assembled. An open air hole 71a is formed in the shell 71, and a hose 70 is connected to the open air hole 71a.

In the valve body 52, a pin 59 is inserted into the piston 58 so as to be loosely fitted thereto, so that the piston 58 shown in FIG.
, It is slightly movable up and down, and is urged toward the valve seat 65 by the spring 64.
Is disposed so as to face the valve seat 65 with a constant distance from.

The electromagnet 53 is provided with a holding guide member 73 fixed inside the shell 71 and a plunger 74 above the holding guide member 73 in FIG. 2, and the flange 75a of the holding guide member 73 holds the coil 75. , Holding guide member 7
It is provided with a pressing member 76 which is guided by 3 and is vertically movable.
The pressing member 76 includes a rod 76a slidably penetrating the holding guide member 73 and a pressing portion 76b.

The electromagnet 53, when excited, applies a downward biasing force to the plunger 74 in FIG.
This urging force presses the rod 76a, and the compression spring 6
The piston 58 is pushed down by the pressing portion 76b against the biasing force of the valve 6, the valve body 52 is seated on the valve seat 65, the inlet 51a is closed, and the braking force is retained.

The controller 54 receives input information such as the loading state detected by various sensors (not shown), the inclination angle of the road surface, and the like, and automatically changes the amount of current flowing to the electromagnet 53 based on the input information, thereby making The magnitude of the urging force applied to the piston 58 via the plunger 74 and the pressing member 76 is automatically controlled by the electromagnet 53 according to the state.

The brake operating device according to the embodiment of the present invention is constructed as described above, and when the vehicle is traveling, the electromagnet 53 is in the off state, and the piston 58 and the valve body 52 have the compression spring 66. It is pushed up by the urging force as shown in FIG. 2, and the inlet 51a is opened.

When the brake pedal 3a is depressed in this state, the compressed air in the air tank 1a is supplied from the inlet 51a of the fluid pressure check valve 50 into the cylinder 51 and passes between the valve body 52 and the valve seat 65. Exit 51b and exit 5
It is supplied to the brake actuator 10 from 1b, and the brake shoe 12 operates the brake. Brake pedal 3
When a is released, the compressed air in the brake actuator 10 is discharged to the outside from the exhaust port (not shown) of the brake control pressure control valve 3, and the brake shoe 12 operates to release the brake.

Next, when the vehicle stops, the information about the stopped state is input to the controller 54, and the electromagnet 53 is turned on after a second, for example, by a signal from the controller 54. When the electromagnet 53 is turned on, the plunger 74
Moves the piston 58 downward in FIG. 2 against the biasing force of the compression spring 66, the valve body 52 contacts the valve seat 65, and the inlet 51a is closed. Therefore, the compressed air inside the brake actuator 10 is retained as it is, and the brake shoe 12 continues the brake operation. For this reason, the brake pedal 3 is temporarily stopped on a slope or the like.
Even if you release a, there is no danger that the vehicle will move naturally,
Eliminates the hassle of pulling the side brakes one by one.

In this stopped state, the brake pedal 3a
When the button is strongly depressed again, only the valve element 52 moves upward in FIG. 2 due to the pressure in the inlet 51a, the inlet 51a is opened, and the brake actuator 10 is replenished with compressed air. Therefore, a braking force adapted to the inclination angle of the slope or the like can be easily obtained, and an excessive pressure does not act on the conduit 9 or the like, and the durability of the device can be improved.

Next, when the vehicle is ready to start by operating the accelerator, clutch, etc., this is input to the controller 54, and the electromagnet 53 is turned off by a signal from the controller 54. When the electromagnet 53 is turned off, the fluid pressure check valve 50 returns to the state shown in FIG. 2. At this time, if the brake pedal 3a is released, the compressed air in the brake actuator 10 will be compressed. Is discharged to the outside from the exhaust port of the brake shoe 12, and the brake shoe 12 operates to release the brake, enabling the vehicle to start. Therefore, especially when starting on an uphill road, a skilled operation such as operating the accelerator and clutch while loosening the side brake is not required, and a smooth start can be made without occurrence of engine stall or vehicle retreat.

FIG. 3 is a graph for explaining the holding pressure range in the relationship between the input pressure PI and the output pressure PO in the brake operating state when the vehicle is stopped, in the brake operating device according to the above embodiment of the present invention. FIG. 4 is a graph for explaining the holding pressure range of the conventional brake operating device in the same case.

In the brake operating device using the fluid pressure operated check valve 50 according to the present invention, the controller 54 changes the amount of current flowing through the coil 75 of the electromagnet 53 to reduce the output pressure chamber 62. The biasing force applied to the piston 58 is determined, the valve body 52 is seated, and the inlet 51a
As shown in FIG. 3, the holding pressure P ₁ in the brake operating state is equal to the pressure of the air tank 1a of 8 kg.
/ Cm ² has an advantage that it can be freely changed to an optimum size in a wide range of 0 to 8 kg / cm ² .

On the other hand, in the conventional brake operating device using the fluid pressure check valve 6, the pressure of the air tank 1b in the signal pressure chamber 37 in the brake operating state is 8 kg.
/ Cm ² is introduced, the output pressure chamber 3 of the piston 34
The ratio of the pressure receiving area SA on the 9 side to the pressure receiving area SB on the signal pressure chamber 37 side of the piston 34 is about 4: 1, and as shown in FIG. 4, the holding pressure of the braking force is 2 kg / cm ^2. Even if the pressure once rises above, the holding pressure P ₂ returns to ² kg / cm ² in order to avoid an excessive pressure on a flat road, and a high holding pressure cannot be maintained.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention.

[0032]

According to the present invention, an electromagnet for applying a biasing force in the direction in which the output pressure chamber is contracted to the piston is provided, and the biasing force applied to the piston by the electromagnet is changed by changing the amount of current flowing through the coil of the electromagnet. By making it variable, it is possible to change the amount of current flowing in the coil of the electromagnet to adjust the holding pressure for seating the valve element and closing the gap between the inlet and the outlet in a wide range. Can be changed according to the state of the vehicle, an air tank for signal pressure and piping for it are not required, the overall structure can be simplified and the degree of freedom of installation can be increased, and the number of required parts can be greatly increased. It is possible to reduce the cost to reduce the cost. According to the present invention, by controlling the fluid pressure check valve by the controller, the brake operating state can be automatically obtained with the optimum holding pressure adapted to the loading state of the vehicle and the inclination angle of the stopped road surface.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a brake operating device using a fluid pressure operated check valve according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a non-actuated state of the fluid pressure operated check valve according to the embodiment of the present invention.

FIG. 3 is a view for explaining a holding pressure range in a relationship between an input pressure and an output pressure in a brake operating state at a vehicle stop in a brake operating device using a fluid pressure check valve according to an embodiment of the present invention. Is a graph of.

FIG. 4 is a graph for explaining a holding pressure range in a relationship between an input pressure and an output pressure in a brake operating state when a vehicle is stopped in the case of a brake operating device using a conventional fluid pressure operated check valve.

FIG. 5 is a schematic configuration diagram of a brake operating device using a conventional fluid pressure operated check valve.

FIG. 6 is a longitudinal sectional view showing a non-operating state of a conventional solenoid valve and a fluid pressure operated check valve.

[Explanation of symbols]

 1a Air tank 3 Brake control pressure control valve 10 Brake actuator 50 Fluid pressure operation check valve 51 Cylinder 51a Inlet 51b Outlet 52 Valve body 53 Electromagnet 54 Controller 58 Piston 61 Atmospheric pressure chamber 62 Output pressure chamber 65 Valve seat 75 Coil 76 Pressing member

Claims (2)

[Claims] 1. A cylinder having an inlet connected to a brake control pressure control valve and an outlet connected to a brake actuator, and an atmospheric pressure chamber and an output pressure chamber are defined in the cylinder to reduce the atmospheric pressure chamber. A piston biased in a direction and a valve body connected to the piston and located in the output pressure chamber, the valve body being mounted in the direction of a valve seat formed in a fluid passage between the inlet and the outlet. In a fluid pressure operated check valve in which the valve body is urged and normally maintains a certain distance from the valve seat, the valve body is arranged to face the valve seat, and the piston exerts a biasing force in a direction in which the output pressure chamber contracts. A fluid pressure operated check valve, wherein an electromagnet applied to the piston is provided, and an urging force applied to the piston by the electromagnet is made variable by changing an amount of current flowing in a coil of the electromagnet. 2. The fluid pressure operated check valve according to claim 1, wherein the controller controls the amount of current flowing through the coil of the electromagnet.