JPH0310117Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a control pressure switching device that changes the control pressure for controlling the brake force in stages according to the speed of a vehicle.

[Conventional technology]

FIG. 1 shows the configuration of a conventional control pressure switching device, where 1 is a passage that supplies pressurized air from an air source (not shown), 2 and 3 are passages that supply pressurized air from passage 1 to predetermined levels, respectively. A high-pressure pressure regulating valve and an intermediate-pressure regulating valve 4 that regulate the pressure to high and intermediate pressures send out pressurized air from the high-pressure pressure regulating valve 2 to the passage 5 when the electric command is on, and send it out when the electric command is off. 6 is an on-type switching solenoid valve that discharges the pressure air from the intermediate pressure regulating valve 3 to the passage 7 when the electric command is on, and exhausts the pressure air that was being sent out when the electric command is off. 8 is a double check valve that selects the higher pressure air from the pressures in the passages 5 and 7 and sends it to the passage 9. 10 is the low pressure air from the external brake equipment (control valve). Aisle 11 and Aisle 9
This is a double check valve that selects air with a higher pressure from among the pressures of Since the passage 9 is at atmospheric pressure, the low pressure air sent from the passage 11 via the control valve is sent to the passage 12.
When a braking force corresponding to the pressure is obtained and a command is received to turn off the solenoid valve 4 and turn on the solenoid valve 6, the medium pressure air from the medium pressure regulating valve 3 is sent to the passage 7. Since the passage 5 is at atmospheric pressure, the check valve 8 is opened and the air is sent to the passage 9 and reaches the check valve 10. Since the pressure is high, the check valve 10 is opened and sent to the passage 12, and a braking force corresponding to the pressure is obtained.Furthermore, when both the solenoid valves 4 and 6 receive a command to turn on, the high pressure is adjusted. The high pressure air from the valve 2 is sent to the passage 5 and reaches the check valve 8. Since this high pressure air has a higher pressure than the medium pressure air from the passage 7, the check valve 8 is opened and the air flows to the passage 9. The air is sent out to the check valve 10, and since the pressure is higher than the low pressure air from the passage 11, the check valve 10 is opened and the air is sent out to the passage 12, so that a braking force corresponding to the pressure can be obtained. It's summery.

[The problem that the idea attempts to solve]

However, the conventional system configured in this way uses two on-type switching solenoid valves and two double-acting check valves to switch the control pressure in stages, so the number of parts is large and the structure is small. This method is complicated and expensive, and has a high incidence of malfunctions, resulting in reliability problems.

Furthermore, as a device for controlling the control pressure for controlling the brake force in stages, there is a device shown in Japanese Patent Application Laid-Open No. 13253/1983, which uses multiple solenoid valves and a dual-interruption system divided into multiple chambers. This structure is also complicated and causes the same problems as the above-mentioned conventional structure.

[Means to solve the problem]

The present invention was devised in view of the problems of the conventional systems described above, and is a control pressure switching device that changes the control pressure to control the brake force in stages according to the speed of the vehicle. A medium-pressure pressure regulating valve and a high-pressure pressure regulating valve that guide air and regulate pressure;
a first OFF-type switching solenoid valve that connects a pressure air passage from the medium-pressure pressure regulating valve and a low-pressure pressure air passage from the brake equipment, and communicates the low-pressure pressure air passage with a discharge passage when an ON command is received; A second OFF valve connects the discharge passage of the first OFF type switching solenoid valve and the pressure air passage from the high-pressure pressure regulating valve and communicates the discharge passage with the pressure air passage to the brake equipment when an ON command is received. It is characterized by being equipped with a type switching solenoid valve.

[Effect]

According to the present invention configured in this way, first,
By cleverly arranging the second off-type switching solenoid valve, the number of parts has been reduced, and by simply switching on and off of both solenoid valves, three levels of pressure (low pressure, medium pressure, and high pressure) can be reliably controlled. It can be easily sent to brake equipment.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained based on FIG. 2.

In the figure, 20 is a passage supplying pressurized air from an air source, 21 and 22 are intermediate pressure regulating valves and high pressure regulating valves that regulate the pressure air from the passage 20 to predetermined intermediate and high pressures, respectively; 24
27 is a pressure air path that guides the pressure air sent out from the medium-pressure pressure regulating valve 21 and the high-pressure pressure regulating valve 22 to the first OFF-type switching solenoid valve 25 and the second OFF-type switching solenoid valve 26; 28 is a low-pressure pressure regulating valve passage from external brake equipment (control valve) to solenoid valve 25; 29 is a pressure air passage that sends out control pressure from solenoid valve 26 to external brake equipment. The first off-type switching solenoid valve 25 opens between the pressure air passage 23 and the discharge passage 27 when an off command is issued;
When the ON command is given, the low-pressure pressure air passage 28 and the discharge passage 27 are opened, and when the OFF command is given, the second OFF type switching solenoid valve 26 opens the pressure air passage 24 and the pressure to the brake equipment. air passage 29
When the ON command is given, the discharge passage 27 and the pressure air passage 29 are opened.

According to the above configuration, when both the first and second off-type switching solenoid valves 25 and 26 receive an on command,
The first off-type switching solenoid valve 25 opens between the low-pressure pressure air passage 28 and the exhaust passage 27, and the second off-type switching solenoid valve 26 opens between the exhaust passage 27 and the pressure air passage 29 to the brake equipment. Storage passage 28
low pressure pressure air from is directed into passageway 29;
Braking force corresponding to that pressure can be obtained, and the first
When a command is received to turn off the off-type switching solenoid valve 25 and turn on the second off-type switching solenoid valve 26, the first off-type switching solenoid valve 25 opens between the pressure air passage 23 and the discharge passage 27, and 2 off-type switching solenoid valve 26
Since the discharge passage 27 and the pressure air passage 29 to the brake equipment are opened, the intermediate pressure regulating valve 21
The medium-pressure air whose pressure is regulated is sent to the passage 29, and a braking force corresponding to the pressure is obtained, and both the first and second OFF-type switching solenoid valves 25 and 26 receive an OFF command. The pressure air passage 23 and the discharge passage 2 are controlled by the first off-type switching solenoid valve 25.
7 is open, but the second off-type switching solenoid valve 26
As a result, the discharge passage 27 and the pressure air passage 29 to the brake equipment are closed, and the pressure air passage 24 and the pressure air passage 29 are opened, so that the high pressure air regulated by the high pressure regulating valve 22 flows into the passage 29. By using two pressure regulating valves and two off-type switching solenoid valves, the control pressure that controls the braking force according to the speed is reduced to low pressure. It can be accurately switched between three levels: medium pressure and high pressure.

[Effect of idea]

As described above, according to the present invention, the first and second off-type switching solenoid valves, intermediate pressure regulating valve, and high pressure regulating valve are skillfully arranged, thereby eliminating the need for the conventionally used double check valve. As a result, the number of parts can be reduced, simplifying the structure and reducing costs. Also, by reducing the number of parts, the number of locations where malfunctions can occur can be reduced. Only by switching the valve on and off, three levels of pressure (low pressure, medium pressure, and high pressure) can be reliably and easily sent to the brake equipment, making hand linkage easy and further improving the reliability of braking action. It is possible to achieve the desired effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional example, and FIG. 2 is a block diagram showing an embodiment of the present invention. 21... Medium pressure pressure regulating valve, 22... High pressure regulating valve, 23, 24... Pressure air passage, 25... First off-type switching solenoid valve, 26... Second off-type switching solenoid valve, 27...Discharge passage, 28...Low pressure air passage, 29...Pressure air passage to brake equipment.

Claims (1)

[Scope of utility model registration request] In a control pressure switching device that changes the control pressure to control the brake force in stages according to the speed of the vehicle,
Connect the medium-pressure pressure regulating valve and high-pressure pressure regulating valve that guide and regulate the pressure air supplied from the air source, the pressure air passage from the medium-pressure pressure regulation valve and the low-pressure pressure air passage from the brake equipment, and issue an ON command. a first off-type switching solenoid valve that connects the low-pressure pressure air passage to a discharge passage when the valve receives the air; A second valve that connects the discharge passage and the pressure air passage to the brake equipment upon receiving the ON command.
1. A control pressure switching device comprising: an off-type switching solenoid valve;