A control system for hydraulic-mechanical combined braking of explosion-proof vehicles in underground coal mines

Abstract

The present invention belongs to the technical field of combined braking control of explosion-proof vehicles in underground coal mines, and specifically is a control system for hydraulic-mechanical combined braking of explosion-proof vehicles in underground coal mines. It includes a mechanical braking control system and a hydraulic braking control system. The mechanical braking control system includes a series dual-circuit brake valve, an accumulator I, an accumulator II, a charging valve, a hydraulic pump, a check valve I, a parking brake valve, a manual pump and a safety valve; the hydraulic braking control system includes an air storage tank, a safety valve, a rotary switch valve, a gear control valve, a hydraulically controlled gas proportional pressure reducing valve, a check valve II, a check valve III, a pressure regulating valve I, a pressure regulating valve II, a shuttle valve I, a shuttle valve II, a control valve, an oil-gas separation device, an exhaust pipe, an exhaust valve, a retarder and an oil pool. The present invention can switch the hydraulic braking and mechanical-hydraulic combined braking control manually, thereby increasing the reliability of vehicle braking, the safety of vehicle operation, and effectively reducing vehicle safety accidents.

Description

Technical Field

[0001] The invention belongs to the technical field of combined braking control of explosion-proof vehicles in underground coal mines, and in particular is a control system for combined hydraulic-mechanical braking of explosion-proof vehicles in underground coal mines. Background Art

[0002] With the rapid development of mining technology in my country, the mining area of ​​near-horizontal coal seams is gradually decreasing, and the number of inclined coal seams is gradually increasing, which has gradually increased the driving slope and ramp distance of trackless auxiliary transportation vehicles. At present, explosion-proof vehicles used for auxiliary transportation in coal mines are divided into articulated explosion-proof vehicles and integral explosion-proof vehicles according to the frame type. The power transmission mode and braking system of the two types of vehicles are different. The integral explosion-proof vehicle adopts an integrated frame, which is generally suitable for slopes less than 10° and transportation distances not exceeding 500m. However, in recent years, in many mines in northern Shanxi, Yanzhou, Shandong and Gansu, the slope of the auxiliary transportation ramp has reached 10-14° and the ramp distance has exceeded 2000m, which has posed a severe test to the braking performance of the vehicle.

[0003] The integral explosion-proof vehicles currently in use rely solely on a single mechanical friction brake. Under the above-mentioned long-distance and high-slope conditions, this will inevitably cause the oil temperature to rise too quickly during braking and fail to remove the brake friction heat in time, causing the brakes to frequently overheat, seal failure and oil leakage, excessive wear of the friction plate, and reduced braking efficiency. Serious problems such as these pose a safety hazard to coal mine production and operation. Summary of the invention

[0004] In order to solve the problem that relying on a single mechanical friction brake will inevitably cause the oil temperature to rise too quickly during braking under the above-mentioned long-distance and high-slope conditions, and the brake friction heat cannot be taken away in time, resulting in frequent overheating of the brake, oil leakage due to seal failure, excessive wear of the friction plate, and reduced braking efficiency, the present invention provides a control system for hydraulic-mechanical combined braking of explosion-proof vehicles in underground coal mines.

[0005] The present invention adopts the following technical scheme: a control system for hydraulic-mechanical combined braking of underground explosion-proof vehicles in coal mines, comprising a mechanical braking control system and a hydraulic braking control system.

[0006] The mechanical brake control system includes a series dual-circuit brake valve, an accumulator I, an accumulator II, a charging valve, a hydraulic pump, a non-return valve I, a parking brake valve, a manual pump and a safety valve. The pressure oil of the hydraulic pump is divided into two paths, one of which is connected to the P port of the charging valve, and the two outlets A1 and A2 of the charging valve are respectively connected to the accumulator I and the accumulator II; the other path is connected to the P port of the safety valve, the T port of the safety valve is respectively connected to the oil tank and the T1 port of the series dual-circuit brake valve, the A1 port and the A2 port of the series dual-circuit brake valve are respectively connected to the front wheel service brake and the rear wheel service brake, the P2 port of the series dual-circuit brake valve is connected to the P port of the parking brake valve through the non-return valve I, the A2 port of the series dual-circuit brake valve is connected to the P port of the mechanical independent brake switching valve, the T port of the mechanical independent brake switching valve is connected to the oil tank, and the A port of the mechanical independent brake switching valve is connected to the hydraulic brake control system.

[0007] The hydraulic brake control system includes an air storage tank, a safety valve, a rotary switch valve, a gear control valve, a hydraulically controlled gas proportional pressure reducing valve, a check valve II, a check valve III, a pressure regulating valve I, a pressure regulating valve II, a shuttle valve I, a shuttle valve II, a control valve, an oil-gas separation device, an exhaust pipe, an exhaust valve, a retarder and an oil pool. The K port of the hydraulically controlled gas proportional pressure reducing valve is connected to the A port of the mechanical independent brake switching valve, the P port of the hydraulically controlled gas proportional pressure reducing valve is connected to the air storage tank through the safety valve, a drain switch is arranged at the bottom of the air storage tank, the A port of the hydraulically controlled gas proportional pressure reducing valve is connected to the P1 port of the shuttle valve II, the P2 port of the shuttle valve II is connected to the A port of the shuttle valve I, and the P1 port of the shuttle valve I is connected to the pressure regulating valve. Valve I, pressure regulating valve I is connected to port B of the gear control valve, a check valve II is connected in parallel to the pressure regulating valve I, port P2 of shuttle valve I is connected to pressure regulating valve II, pressure regulating valve II is connected to port A of the gear control valve, and a check valve III is connected in parallel to the pressure regulating valve II; port P of the gear control valve is connected to port A of the rotary switch valve, and port P of the rotary switch valve is connected to the air storage tank; port A of shuttle valve II is connected to port P and port K of the control valve, port A of the control valve is connected to the oil pool, port R of the control valve is connected to the inlet of the oil-gas separation device, an exhaust pipe is arranged on the exhaust port of the oil-gas separation device, the outlet of the oil-gas separation device is connected to the retarder through the exhaust valve, and the retarder is connected to the oil pool.

[0008] Compared with the prior art, the present invention can switch the hydraulic brake and mechanical-hydraulic combined brake control manually. The mechanical brake adopts hydraulic control, and the combined brake is automatically controlled. During combined braking, the hydraulic brake is proportional. The hydraulic independent brake adopts pneumatic control to achieve two-speed control. In the current environment of strict control of the braking system and safety of underground explosion-proof rubber-wheeled vehicles, the reliability of vehicle braking and the safety of vehicle operation are increased, and the safety accidents of vehicles are effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a hydraulic-mechanical combined brake control system;

[0010] Figure 2 It is a mechanical brake control system;

[0011] Figure 3 It is a hydraulic brake control system;

[0012] In the figure, 1-front wheel service brake, 2-rear wheel service brake, 3-tandem dual-circuit brake valve, 4-accumulator I, 5-accumulator II, 6-filling valve, 7-hydraulic pump, 8-check valve I, 9-parking brake valve, 10-hand pump, 11 -parking brake, 12-air tank, 13-drain switch, 14-safety valve, 15-rotary switch valve, 16-gear control valve, 17-hydraulic-controlled gas proportional pressure reducing valve, 18-check valve II, 19-pressure regulating valve I, 20-check valve III, 21-pressure regulating valve II, 22-shuttle valve I, 23-shuttle valve II, 24-control valve, 25-oil-gas separation device, 26-exhaust pipe, 27-exhaust valve, 28-retarder, 29-oil pool, 30-oil pipe, 31-mechanical independent brake switching valve, 32-safety valve, 33-double hydraulic-controlled valve, 34-filter, 35-throttle valve, 36-check valve, 37-hydraulic-controlled valve, 38-double-way shuttle valve. DETAILED DESCRIPTION

[0013] A control system for hydraulic-mechanical combined braking of underground explosion-proof vehicles in coal mines comprises a mechanical braking control system and a hydraulic braking control system.

[0014] The mechanical brake control system includes a series-type dual-circuit brake valve 3, an accumulator I4, an accumulator II5, a charging valve 6, a hydraulic pump 7, a one-way valve I8, a parking brake valve 9, a manual pump 10 and a safety valve 32. The pressure oil of the hydraulic pump 7 is divided into two paths, one of which is connected to the P port of the charging valve 6, and the two outlets A1 and A2 of the charging valve 6 are respectively connected to the accumulator I4 and the accumulator II5; the other is connected to the P port of the safety valve 32, and the T port of the safety valve 32 is connected to the oil tank and the series The T1 port of the tandem dual-circuit brake valve 3, the A1 port and the A2 port of the tandem dual-circuit brake valve 3 are connected to the front wheel service brake 1 and the rear wheel service brake 2 respectively, the P2 port of the tandem dual-circuit brake valve 3 is connected to the P port of the parking brake valve 9 through the one-way valve I8, the A2 port of the tandem dual-circuit brake valve 3 is connected to the P port of the mechanical independent brake switching valve 31, the T port of the mechanical independent brake switching valve 31 is connected to the oil tank, and the A port of the mechanical independent brake switching valve 31 is connected to the hydraulic brake control system.

[0015] The hydraulic brake control system includes an air storage tank 12, a safety valve 14, a rotary switch valve 15, a gear control valve 16, a hydraulically controlled gas proportional pressure reducing valve 17, a one-way valve II18, a one-way valve III20, a pressure regulating valve I19, a pressure regulating valve II21, a shuttle valve I22, a shuttle valve II23, a control valve 24, an oil-gas separation device 25, an exhaust pipe 26, an exhaust valve 27, a retarder 28 and an oil pool 29. The K port of the hydraulically controlled gas proportional pressure reducing valve 17 is connected to the A port of the mechanical independent brake switching valve 31, the P port of the hydraulically controlled gas proportional pressure reducing valve 17 is connected to the air storage tank 12 through the safety valve 14, a drain switch 13 is arranged at the bottom of the air storage tank 12, the A port of the hydraulically controlled gas proportional pressure reducing valve 17 is connected to the P1 port of the shuttle valve II23, the P2 port of the shuttle valve II23 is connected to the A port of the shuttle valve I22, the P1 port of the shuttle valve I22 is connected to the regulating valve 14, and the P2 port of the shuttle valve II23 is connected to the A port of the shuttle valve I22. The pressure regulating valve I19 is connected to the B port of the gear control valve 16, and the pressure regulating valve I19 is connected in parallel with a check valve II18. The P2 port of the shuttle valve I22 is connected to the pressure regulating valve II21, and the pressure regulating valve II21 is connected to the A port of the gear control valve 16, and the check valve III20 is connected in parallel to the pressure regulating valve II21; the P port of the gear control valve 16 is connected to the A port of the rotary switch valve 15, and the P port of the rotary switch valve 15 is connected to the air storage tank 12; the A port of the shuttle valve II23 is connected to the P port and the K port of the control valve 24, the A port of the control valve 24 is connected to the oil pool 29, the R port of the control valve 24 is connected to the inlet of the oil-gas separation device 25, and the exhaust port of the oil-gas separation device 25 is provided with an exhaust pipe 26, and the outlet of the oil-gas separation device 25 is connected to the retarder 28 through the exhaust valve 27, and the retarder 28 is connected to the oil pool 29.

[0016] The hydraulic pump 7 is driven by the engine. After the engine is started, the hydraulic pump runs. The filling valve 6 adopts a dual-circuit filling valve, and its main function is to fill the accumulator and control its filling pressure. The main functions of the accumulators I4 and II5 are to store and release the hydraulic energy required for braking, stabilize the brake oil pressure, and ensure a large amount of oil supply when the brake is continuously stepped on. They control the braking of the front and rear wheels respectively and are independent of each other. The main function of the series dual-circuit brake valve 3 is to control the pressure oil from the accumulator to enter the front and rear wheel service brakes in proportion to achieve vehicle braking. If one of the brake circuits of the front or rear wheel fails, the other brake circuit can still work. The front and rear wheel service brakes are hydraulically braked and released by springs. When the pedal of the dual-circuit brake valve 3 is stepped on, the pressure oil in the two accumulators enters the front and rear service brakes through the upper and lower chambers of the valve respectively, acts on the brake piston, presses the friction plate to brake the wheel, and the output brake pressure is proportional to the angle of the brake pedal stepped on. When the foot pedal is released, the high-pressure oil in the brake flows back to the oil tank to release the brake.

[0017] The pressure oil of the hydraulic pump 7 is divided into two paths, one path enters the P port of the charging valve 6, and the other path reaches the P port of the safety valve 32. The pressure oil entering the charging valve 6 reaches the two outlets A1 and A2 of the shuttle valve 38 after passing through the internal hydraulic control valve 33, the filter 34, the throttle valve 35 and the one-way valve 36, and fills the two accumulators 4 and 5. When the pressure in the two accumulators reaches the set pressure of the charging valve, the double hydraulic control valve switches to the right position, and the pressure oil from the hydraulic pump flows back to the oil tank through the P port of the charging valve and the bypass port O. When braking is required, the brake pedal is stepped on, and the pressure oil from the two accumulators is connected to the A1 and A2 ports of the series dual-circuit brake valve 3 through the P1 and P2 of the valve and enters the piston chambers of the front and rear wheel service brakes 1 and 2, and the compression spring brakes the vehicle. When the pedal is released, the oil in the piston chambers of the front and rear wheel service brakes 1 and 2 flows back to the oil tank through A1 and A2 of the series dual-circuit brake valve 3 and T1 and T2 ports, and the brake is released. At the same time, a pressure oil in the accumulator 4 is connected to the pressure port P of the parking brake valve 9 through the one-way valve 8. When the position shown in the figure, the oil in the spring chamber of the parking brake 11 returns to the oil tank through the A port and T port of the parking brake valve 9. At this time, the parking brake is in the spring braking position and the vehicle is stationary. When the vehicle needs to move and the brake is released, the parking brake valve 9 is reversed. At this time, the pressure oil from the accumulator passes through the P port of the parking brake valve 9, and after internal decompression, it enters the spring chamber of the parking brake through the A port to compress the spring and release the brake. When the vehicle breaks down and needs to be towed, the parking brake spring chamber can be filled with oil through the manual pump 10 to release the brake.

[0018] A path of pressure oil is led out from the accumulator I4 through the one-way valve 8 to the parking brake valve 9. The output pressure of the parking brake valve 9 is a certain value, which acts on the central brake 11. The central brake 11 is spring braked and hydraulically released. When there is no pressure output from the parking brake valve, it is in a spring brake state. When the parking brake valve is actuated, a certain pressure is output to act on the central brake, the compression spring overcomes the spring force, and the brake is released.

[0019] The manual pump 10 is used to manually release the central brake and to tow the vehicle when the vehicle breaks down or loses power.

[0020] The hydraulic brake uses pneumatic control. The key component of the hydraulic brake is the retarder. The amount of oil on the retarder determines the magnitude of its output braking force. The control device for the retarder oil amount uses pneumatic control.

[0021] The hydraulic brake control adopts a pneumatic control system, which has two modes: manual control and automatic control. The manual control adopts two-speed control, and the automatic linkage control adopts proportional control.

[0022] Manual control is when only hydraulic braking is needed to decelerate the explosion-proof vehicle without mechanical braking. The circuit is equipped with a pneumatic rotary switch valve 15. The first gear is opened by the rotary valve, and the second gear can be switched after the gear control valve 16 is operated. The two gears are mainly achieved by setting different pressures of the two pressure reducing valves I19 and II21.

[0023] The compressed air pressure in the air tank is maintained at 0.6-0.8MPa. The position shown in the figure is the state where the retarder auxiliary brake is not used, and the compressed air is sealed at the rotary switch valve 15. When the retarder brake is required, the rotary switch valve 15 is opened to make it work in the left position. At this time, the compressed air goes from the P port to the A port, the gear control valve works in the right position, P and A are connected, and after being reduced by the pressure reducing valve 21, it reaches the P2 port of the shuttle valve 22. The set pressure of the pressure reducing valve 21 is 0.15MPa, which is the first gear of the retarder. The compressed air goes from the shuttle valve A port to the P2 port of the shuttle valve 23 to the A port and then reaches the pressure port P port of the control valve 24, and all the way to the control port K of the control valve 24 to make the control valve work in the upper position. The compressed air goes from P to A and enters the control port K of the oil pool 29, compressing the oil, and the oil enters the retarder 28 housing through the oil pipe 30.

[0024] The amount of oil entering the housing is determined by the pressure of the compressed air at the control port K. When the braking force needs to be increased, the gear control valve 16 is operated to work in the left position. At this time, the compressed air passes through the rotary switch valve 15, reaches B through the P port, and reaches P1 of the shuttle valve 22 through the pressure reducing valve 19. After reaching A port, it passes through P2 of the shuttle valve 23 to A port, and enters the control port K of the oil pool 29 through the control valve 24. The set pressure of the pressure reducing valve 19 is 0.3MPa, which increases the amount of oil entering the retarder, and the pressure of the P port passes through the one-way valve 7 and the gear control valve A port to the R port to exhaust.

[0025] When the retarder is not needed to work, turn off the rotary switch valve 15, and the compressed air at the pressure port P of the control valve 24 is exhausted through the shuttle valve II23, the shuttle valve I22, the one-way valve 18, the gear control valve 16 and the knob switch valve 15. At the same time, the pressure at the control port K1 of the control valve 24 disappears, and the control valve 24 is in the lower position under the action of the spring. The compressed air at the control port K passes through the A port to the R port of the control valve 24 and enters the oil-gas separation device 25. A special pipeline for gas flow is set inside the oil-gas separation device. After the compressed air flows through it, the oil and liquid in the air are separated and enter the shell, and the clean compressed air is discharged into the atmosphere through the exhaust pipe 26, reducing the pollution to the environment.

[0026] An exhaust valve 27 is provided at the highest point of the retarder, and the air in the housing enters the oil-gas separation device 25 through the exhaust valve 27. The compressed air after oil-gas separation flows into the exhaust pipe 26 and is discharged into the atmosphere.

[0027] Whether the mechanical brake is controlled independently or linked with the hydraulic brake is controlled by the switching valve 31. When the switching valve 31 is in the lower position, the control port K of the hydraulic-controlled gas proportional valve 17 returns to the oil tank through the switching valve, and the pressure oil drawn from the brake valve is sealed by the switching valve. At this time, the mechanical brake operates independently.

[0028] When the switching valve is manually operated to the upper position, the pressure oil at the brake valve outlet reaches the control port K of the hydraulic-controlled gas proportional pressure reducing valve 17 through the switching valve. When the brake valve is stepped on for mechanical braking, the brake valve outlet pressure reaches the set opening pressure of the hydraulic-controlled gas proportional pressure reducing valve 17, and the hydraulic brake also starts to work at the same time, realizing the joint control of mechanical and hydraulic braking.

[0029] The air pressure value of the output pressure A port of the hydraulic-controlled air proportional valve 17 changes proportionally with the value of the control oil K port within the set range. In this way, the compressed air at port A reaches port A through port P1 of the shuttle valve 23, and then proportionally inputs the oil into the retarder 28 through port P of the control valve 24 and the control port of the A port oil pool 29, so that the retarder outputs a proportional braking torque, automatically realizing the linkage of mechanical and hydraulic braking.

[0030] Mechanical independent braking control, hydraulic independent braking control and mechanical-hydraulic linkage braking control can be achieved through various control methods.

Claims

1. A control system for hydraulic-mechanical combined braking of explosion-proof vehicles in coal mines, characterized in that: Including mechanical brake control system and hydraulic brake control system, The mechanical brake control system comprises a series dual-circuit brake valve (3), an accumulator I (4), an accumulator II (5), a charging valve (6), a hydraulic pump (7), a check valve I (8), a parking brake valve (9), a manual pump (10) and a safety valve II (32). The pressure oil of the hydraulic pump (7) is divided into two paths, one of which is connected to the P port of the charging valve (6), and the two outlets A1 and A2 of the charging valve (6) are connected to the accumulator I (4) and the accumulator II (5) respectively; the other path is connected to the P port of the safety valve II (32), and the T port of the safety valve II (32) is connected to the oil tank and the T1 port of the tandem dual-circuit brake valve (3) respectively, the A1 port and the A2 port of the tandem dual-circuit brake valve (3) are connected to the front wheel service brake (1) and the rear wheel service brake (2) respectively, the P2 port of the tandem dual-circuit brake valve (3) is connected to the P port of the parking brake valve (9) through the non-return valve I (8), the A2 port of the tandem dual-circuit brake valve (3) is connected to the P port of the mechanical independent brake switching valve (31), the T port of the mechanical independent brake switching valve (31) is connected to the oil tank, and the A port of the mechanical independent brake switching valve (31) is connected to the hydraulic brake control system; The hydraulic brake control system comprises an air storage tank (12), a safety valve I (14), a knob switch valve (15), a gear control valve (16), a hydraulically controlled gas proportional pressure reducing valve (17), a check valve II (18), a check valve III (20), a pressure regulating valve I (19), a pressure regulating valve II (21), a shuttle valve I (22), a shuttle valve II (23), a control valve (24), an oil-gas separation device (25), an exhaust pipe (26), an exhaust valve (27), and a retarder (28). The hydraulic-controlled gas proportional pressure reducing valve (17) is connected to the oil pool (29), the K port of the hydraulic-controlled gas proportional pressure reducing valve (17) is connected to the A port of the mechanical independent brake switching valve (31), the P port of the hydraulic-controlled gas proportional pressure reducing valve (17) is connected to the gas storage tank (12) through the safety valve I (14), and a drainage switch (13) is provided at the bottom of the gas storage tank (12), the A port of the hydraulic-controlled gas proportional pressure reducing valve (17) is connected to the P1 port of the shuttle valve II (23), the P2 port of the shuttle valve II (23) is connected to the A port of the shuttle valve I (22), and the P1 port of the shuttle valve I (22) is connected to the The pressure regulating valve I (19) is connected to the B port of the gear control valve (16), and the pressure regulating valve I (19) is connected in parallel with the check valve II (18). The P2 port of the shuttle valve I (22) is connected to the pressure regulating valve II (21), and the pressure regulating valve II (21) is connected to the A port of the gear control valve (16), and the check valve III (20) is connected in parallel with the pressure regulating valve II (21); the P port of the gear control valve (16) is connected to the A port of the knob switch valve (15), and the knob switch valve (15) is connected to the P port of the gear control valve (16). ) is connected to the gas storage tank (12); the A port of the shuttle valve II (23) is connected to the P port and the K port of the control valve (24); the A port of the control valve (24) is connected to the oil pool (29); the R port of the control valve (24) is connected to the inlet of the oil-gas separation device (25); an exhaust pipe (26) is provided on the exhaust port of the oil-gas separation device (25); the outlet of the oil-gas separation device (25) is connected to the retarder (28) through the exhaust valve (27); and the retarder (28) is connected to the oil pool (29).

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