An emergency brake release system and control method for an underground shovel

Abstract

The present application belongs to the technical field of underground mining transportation equipment, and particularly relates to an emergency brake release system and control method for an underground shovel-truck, wherein the emergency brake release system comprises a front axle brake and a rear axle brake, and a brake release valve group is connected to the oil inlet of each of the front axle brake and the rear axle brake, the brake release valve group comprises a first brake valve and a second brake valve arranged in parallel, the oil outlet of each of the first brake valve and the second brake valve is connected to the front axle brake or the rear axle brake, the oil inlet of the first brake valve is connected to a liquid filling valve, the oil inlet of the liquid filling valve is connected to the oil outlet of a brake pump, the oil inlet of the second brake valve is connected to a brake control valve group, and the oil inlet of the brake control valve group is connected to a trailer reversing valve, the present application sets multiple oil supply units according to common failure modes of the shovel-truck, and can automatically switch the oil supply path through simple operation, thereby realizing brake release and having good failure adaptability.

Description

Technical Field

[0001] This invention belongs to the technical field of underground mining transportation equipment, and particularly relates to an emergency brake release system and control method for underground loader. Background Technology

[0002] In underground mining operations, underground loaders, as core material transfer and excavation equipment, need to operate in complex and harsh environments for a long time. Their operational safety and emergency response efficiency are directly related to the continuity of mine production and the safety of workers.

[0003] Among them, the braking system is a key safety protection module of the loader. If the brake cannot be released normally due to equipment failure, the faulty equipment will be stuck in the work area, which will not only block the mine transportation channel and cause production to stop, but may also expose it to safety hazards due to the inability to evacuate in time, causing secondary accidents.

[0004] Chinese utility model patent application number 202322789046.3 discloses a hydraulic braking system and a light road roller capable of emergency brake release. By manually activating the emergency brake valve group, the rodless chamber of the hydraulic cylinder is connected to the brake. By turning the steering wheel, the oil in the rodless chamber enters the brake, thereby releasing the brake and enabling operations such as short-distance towing.

[0005] This emergency brake release method is only applicable to the core fault scenario of "engine not working properly or low fuel pressure". The fault coverage is limited and it is difficult to deal with diverse equipment faults in practical applications. In addition, it requires manual switching of the emergency brake valve group and driving the oil flow by turning the steering wheel, which is not suitable for large mining transportation equipment. Summary of the Invention

[0006] The main technical problem to be solved by the present invention is to provide an emergency brake release system and control method for downhole loaders. The system is designed with multiple oil supply units according to the common fault modes of loaders. The oil supply path can be automatically switched through simple operation, thereby realizing brake release and having good fault adaptability.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: An emergency brake release system for an underground loader includes a front axle brake and a rear axle brake. A brake release valve assembly is connected to the oil inlet of each of the front and rear axle brakes. The brake release valve assembly includes a first brake valve and a second brake valve connected in parallel. The oil outlets of the first and second brake valves are connected to either the front or rear axle brake. A filling valve is connected to the oil inlet of the first brake valve, and the oil inlet of the filling valve is connected to the oil outlet of the brake pump. A brake control valve assembly is connected to the oil inlet of the second brake valve, and a trailer directional valve is connected to the oil inlet of the brake control valve assembly.

[0008] The following are further optimizations of the above technical solution by the present invention: The brake control valve assembly includes a first directional valve and a first check valve. The control ports of the first directional valve and the first check valve are both connected to the oil outlet of the brake pump. Two of the oil ports of the first directional valve are connected to the trailer directional valve and the first check valve, respectively, and the other oil port is connected to a pressure reducing valve.

[0009] Further optimization: A second directional valve is connected to the pipeline between the first directional valve and the pressure reducing valve. The second directional valve is set in parallel with the pressure reducing valve. One oil port of the second directional valve is connected to the oil tank, and the control port is connected to one oil port of the first check valve.

[0010] Further optimization: An auxiliary accumulator is also connected between the first check valve and the second directional valve, and the auxiliary accumulator is set in parallel with the second directional valve.

[0011] Further optimization: An emergency electric pump is also provided, with a trailer accumulator and a filling valve accumulator connected in parallel at the oil outlet of the emergency electric pump. The filling valve accumulator is connected to the filling valve.

[0012] Further optimization: A third reversing valve is connected to the pipeline between the filling valve accumulator and the emergency electric pump. A second check valve is also installed between the trailer accumulator and the filling valve accumulator. The second check valve conducts from the filling valve accumulator to the trailer accumulator.

[0013] Further optimization: A method for releasing the emergency brake of an underground loader, based on the emergency brake release system of an underground loader as described in the above claims, characterized by including the following operating conditions: Normal operating conditions: The trailer directional valve does not switch. When the brake pump is started, one line of hydraulic fluid controls the first directional valve and the first check valve to switch and open, while hydraulic fluid is discharged from the control end of the second directional valve. The other line of hydraulic fluid enters the front axle brake and the rear axle brake in sequence through the filling valve and the first brake valve, releasing the brakes. Fault condition: When the brake pump fails, the emergency electric pump is started, and the third directional valve is energized and reversed at the same time. The oil in the emergency electric pump fills the accumulator of the charging valve through the third directional valve. After the filling is completed, the third directional valve is de-energized and returns to its original position. The oil in the accumulator of the charging valve enters the front axle brake and the rear axle brake through the two first brake valves respectively, releasing the brake. Fault condition: When the vehicle cannot move normally, the trailer pulls the trailer hook to reverse the trailer reversing valve. The accumulator of the charging valve and the trailer accumulator supply oil together. One path of oil output from the brake pump controls the reversing of the first reversing valve. At the same time, the first check valve opens, driving the second reversing valve to reverse and release oil. The other path of oil enters the front axle brake and the rear axle brake through the charging valve and the first brake valve, releasing the brake. Fault condition: When the faulty vehicle cannot start, the trailer pulls the trailer hook to reverse the trailer reversing valve. The trailer accumulator and the charging valve accumulator supply oil at the same time. The first reversing valve and the first check valve do not operate. After the oil is depressurized by the pressure reducing valve, part of the oil controls the reversing of the first brake valve and the second brake valve, and the other part passes through the second brake valve to enter the front axle brake and the rear axle brake respectively, releasing the brakes.

[0014] The present invention, by adopting the above technical solution, has the following beneficial effects: The emergency brake release system of this invention is equipped with multiple oil supply units, including a brake pump, an emergency electric pump, a trailer accumulator, and a charging valve accumulator, which correspond to different working conditions such as normal use, brake pump failure, vehicle inability to move, and vehicle inability to start. Regardless of whether the fault originates from the power system, transmission system, or hydraulic system, the brake can be released by automatically switching the oil supply path, effectively solving the problem of poor adaptability to transmission system faults.

[0015] The brake release valve assembly of the present invention adopts a parallel structure of a first brake valve and a second brake valve, and the two are connected to different oil supply devices. Corresponding to different fault modes, the oil circuit can be automatically switched, forming a double guarantee for the brake release function of the loader, ensuring that the loader can still move under complex working conditions.

[0016] The emergency brake release system of the present invention uses a trailer hook to control the reversing valve of the trailer and uses the oil stored in the accumulator to complete the brake release. Especially when the vehicle cannot start, there is no need to rely on the brake pump. The dual brake valves are directly controlled by the oil supply from the accumulator, ensuring that the disabled vehicle can be towed to a safe location and avoiding the safety hazards caused by being stranded.

[0017] The emergency brake release system of this invention only requires pressing the emergency brake switch or hooking up the trailer hitch in case of a fault, without requiring professional and complicated operating skills. Furthermore, the front axle brake and rear axle brake adopt the common structure of mining machinery, without the need for major modifications to the core components of the original braking system of the loader, reducing the cost and difficulty of system upgrades and facilitating its application on existing equipment.

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the oil circuit connection of the emergency braking release system of the present invention.

[0020] In the diagram: 1. Front axle brake; 2. Rear axle brake; 3. Brake release valve assembly; 301. First brake valve; 302. Second brake valve; 4. Brake control valve assembly; 401. First directional valve; 402. First check valve; 403. Second directional valve; 404. Pressure reducing valve; 5. Trailer directional valve; 6. Second check valve; 7. Third directional valve; 8. Trailer accumulator; 9. Filling valve accumulator; 10. Auxiliary accumulator. Detailed Implementation

[0021] An emergency brake release system for an underground loader, such as Figure 1 As shown, the device includes a front axle brake 1 and a rear axle brake 2 for controlling the braking of the front and rear axles of the loader, respectively. A brake release valve assembly 3 is connected to the oil inlet of the front axle brake 1 and the rear axle brake 2. The front axle brake 1 and the rear axle brake 2 are commonly used structures in existing mining machinery, and will not be described in detail in this invention. When the loader needs to move, external oil enters the rod chamber of the brake cylinder of the front axle brake 1 and the rear axle brake 2 through the brake release valve assembly 3. The oil pressure overcomes the spring force and pushes the piston rod of the brake cylinder to retract, releasing the braking of the front and rear axles.

[0022] The brake release valve group 3 includes a first brake valve 301 and a second brake valve 302 arranged in parallel. The oil inlet ends of the first brake valve 301 and the second brake valve 302 are respectively connected to different oil supply devices, and the oil outlet ends are connected to the front axle brake 1 or the rear axle brake 2. This is to ensure that the brake can be released under different working conditions, so as to realize the movement of the loader.

[0023] In this embodiment, the first brake valve 301 and the second brake valve 302 are two-position two-way hydraulic directional valves. The first brake valve 301 is a normally open valve and the second brake valve 302 is a normally closed valve. By controlling the valve cores of the first brake valve 301 and the second brake valve 302 to switch simultaneously, the brake oil circuit can be switched. When one oil circuit fails, the brake release function can still be used normally.

[0024] In this embodiment, the oil inlet of the first brake valve 301 is connected to a filling valve, and the oil inlet of the filling valve is connected to the oil outlet of the brake pump (not shown in the figure). Under normal working conditions, the brake pump works to make high-pressure oil pass through the filling valve and the first brake valve 301 in sequence, and enter the front axle brake 1 and the rear axle brake 2 to complete the brake release of the loader.

[0025] The oil inlet of the second brake valve 302 is connected to the brake control valve group 4, and the oil inlet of the brake control valve group 4 is connected to the trailer reversing valve 5. The trailer reversing valve 5 is a two-position three-way reversing valve, and its control port is connected to the trailer hook. Under normal conditions, one of the oil ports of the trailer reversing valve 5 is connected to the oil tank. When the vehicle is unable to move due to a malfunction, the trailer hook is dragged by a trailer to control the trailer reversing valve 5 to switch directions, thus completing the switching of the oil supply source of the entire system.

[0026] The brake control valve group 4 includes a first directional valve 401 and a first check valve 402. In this embodiment, the first directional valve 401 is a hydraulically controlled two-position three-way directional valve, and the first check valve 402 is a hydraulically controlled check valve. The control ports of both are connected to the oil outlet of the brake pump. The high-pressure oil output by the brake pump controls the first directional valve 401 and the first check valve 402 to operate synchronously.

[0027] Two of the oil ports of the first reversing valve 401 are connected to the trailer reversing valve 5 and the first check valve 402 respectively, to realize the forward or reverse flow of oil in the brake control valve group 4 under different working conditions. The other oil port of the first reversing valve 401 is connected to a pressure reducing valve 404, which can accurately adjust the system control oil pressure and output control oil with appropriate pressure to effectively meet the rated pressure requirements of different models of brakes and ensure the stable adaptation and reliable operation of the brake actuator.

[0028] A second directional valve 403 is also connected to the pipeline between the first directional valve 401 and the pressure reducing valve 404. Specifically, one of the oil ports of the second directional valve 403 is connected to the pipeline between the first directional valve 401 and the pressure reducing valve 404 and is set in parallel with the pressure reducing valve 404. The other oil port of the second directional valve 403 is connected to the oil tank, and the control port is connected to one of the oil ports of the first check valve 402.

[0029] To ensure that the front and rear axles can still be released normally in the event of a brake pump failure, the emergency brake release system of the underground loader is also equipped with an emergency electric pump. The outlet of the emergency electric pump is connected in parallel to a trailer accumulator 8 and a filling valve accumulator 9. The filling valve accumulator 9 is connected to the filling valve and can directly supply oil to the brake release valve group 3 through the filling valve.

[0030] A third directional valve 7 is connected to the pipeline between the filling valve accumulator 9 and the emergency electric pump. A second check valve 6 is also installed between the trailer accumulator 8 and the filling valve accumulator 9. The second check valve 6 is open from the filling valve accumulator 9 to the trailer accumulator 8.

[0031] In this embodiment, the third reversing valve 7 is a two-position two-way solenoid reversing valve. By pressing the emergency brake switch in the cab, the solenoid valve of the third reversing valve 7 can be energized, the valve core can be reversed, and the pipeline between the emergency electric pump and the charging valve accumulator 9 can be connected.

[0032] An auxiliary accumulator 10 is also connected between the first one-way valve 402 and the second reversing valve 403. The auxiliary accumulator 10 is set in parallel with the second reversing valve 403. When the trailer reversing valve 5 reverses, the trailer accumulator 8 and the charging valve accumulator 9 supply oil to the brake control valve group 4. At this time, the brake pump is started, and the oil controls the first reversing valve 401 and the first one-way valve 402 to reverse. The oil in the trailer accumulator 8 and the charging valve accumulator 9 passes through the trailer reversing valve 5, the first reversing valve 401 and the first one-way valve 402 in sequence. Then, one path of oil enters the control terminal of the second reversing valve 403 to control its reversal, and the other path of oil charges the auxiliary accumulator 10. The oil in the auxiliary accumulator 10 is used to stabilize the oil circuit pressure, so that the second reversing valve 403 maintains the reversing state and ensures that the oil circuit is unobstructed.

[0033] An emergency brake release control method for an underground loader is implemented based on the aforementioned emergency brake release system for an underground loader. Under different operating conditions, the internal components of the system cooperate with each other to ensure that the brake can be released under different faults, and the vehicle can be moved to a safe location.

[0034] Normal operating condition: When the trailer reversing valve 5 does not reverse, the brake pump is started, and the hydraulic control first reversing valve 401 and first check valve 402 reverse and open. At this time, the hydraulic fluid at the control end of the second reversing valve 403 passes through the first check valve 402, the first reversing valve 401 and the trailer reversing valve 5 in sequence and returns to the oil tank, ensuring that the first brake valve 301 is in the open state and the second brake valve 302 is in the open state. The other hydraulic fluid from the brake pump outlet passes through the filling valve and the first brake valve 301 in sequence and enters the front axle brake 1 and the rear axle brake 2, releasing the braking of the front and rear axles.

[0035] Fault Condition 1: The vehicle can start normally and has normal driving ability, but the brake pump is faulty and cannot release the brake normally, requiring the use of an emergency electric pump to supply oil.

[0036] Start the disabled vehicle, turn on the emergency brake switch in the cab, the emergency electric pump starts, and at the same time the third reversing valve 7 is energized and reversed. The oil from the emergency electric pump goes through the third reversing valve 7 to charge the accumulator 9 of the charging valve, and through the other to charge the trailer accumulator 8.

[0037] After the filling is completed, the third reversing valve 7 is de-energized and returns to its original position. The oil in the filling valve accumulator 9 enters the front axle brake 1 and the rear axle brake 2 through the two first brake valves 301 respectively, releasing the brakes on the front and rear axles and ensuring that the faulty vehicle can move normally. In this fault mode, the trailer accumulator 8 does not perform reverse oil supply.

[0038] Fault Condition 2: The vehicle can start normally and release the brakes, but it does not have the ability to move normally (e.g., the gearbox or drive shaft is damaged). In this case, a trailer needs to be used to tow the faulty vehicle with a trailer hitch.

[0039] When the disabled vehicle is started, the trailer pulls the trailer hook, causing the trailer reversing valve 5 to switch. At this time, the oil in the accumulator 9 of the charging valve flows into the oil circuit of the trailer accumulator 8 through the second check valve 6, and the two supply oil together.

[0040] The brake pump pumps oil, and a portion of the oil controls the reversing of the first directional valve 401. At the same time, the first check valve 402 opens, and the hydraulic oil supplied by the charging valve accumulator 9 and the trailer accumulator 8 enters the control port of the second directional valve 403 through the trailer directional valve 5, the first directional valve 401, and the first check valve 402. The second directional valve 403 reverses and connects with the oil tank, and the oil is discharged from the outlet of the second directional valve 403. During this process, the auxiliary accumulator 10 maintains the pipeline pressure to ensure that the second directional valve 403 does not return to its original position. The other portion of the oil supplied by the brake pump enters the front axle brake 1 and the rear axle brake 2 through the charging valve and the first brake valve 301, thereby releasing the brakes on the faulty vehicle.

[0041] In other words, under this fault condition, although the trailer directional valve 5 reverses, the hydraulic oil for the brake release action is still supplied by the brake pump because the brake pump can work normally.

[0042] Fault Condition 3: The vehicle cannot start. In this case, the brake pump cannot work and the vehicle is not capable of moving. A tow truck is also required to tow the vehicle.

[0043] When the trailer pulls the trailer hook, the trailer reversing valve 5 reverses, and the trailer accumulator 8 and the charging valve accumulator 9 supply oil at the same time. Since the brake pump cannot work at this time, the first reversing valve 401 and the first check valve 402 do not operate, and the first reversing valve 401 is connected to the pressure reducing valve 404.

[0044] The oil supplied by the trailer accumulator 8 and the charging valve accumulator 9 is depressurized by the pressure reducing valve 404. Part of it enters the control ports of the first brake valve 301 and the second brake valve 302, controlling them to switch directions simultaneously. The other part enters the front axle brake 1 and the rear axle brake 2 through the two second brake valves 302 respectively, completing the brake release and transferring the faulty vehicle to a safe location for repair.

[0045] For those skilled in the art, any changes, modifications, substitutions, and variations made to the embodiments without departing from the principles and spirit of the present invention, based on the teachings of the present invention, still fall within the protection scope of the present invention.

Claims

1. An emergency brake release system for an underground loader, comprising a front axle brake (1) and a rear axle brake (2), wherein a brake release valve assembly (3) is connected to the oil inlet of each of the front axle brake (1) and the rear axle brake (2), characterized in that: The brake release valve assembly (3) includes a first brake valve (301) and a second brake valve (302) arranged in parallel. The oil outlets of the first brake valve (301) and the second brake valve (302) are connected to the front axle brake (1) or the rear axle brake (2). The oil inlet of the first brake valve (301) is connected to a filling valve, and the oil inlet of the filling valve is connected to the oil outlet of the brake pump. The oil inlet of the second brake valve (302) is connected to a brake control valve assembly (4), and the oil inlet of the brake control valve assembly (4) is connected to a trailer reversing valve (5). The brake control valve assembly (4) includes a first directional valve (401) and a first check valve (402). The control ports of both the first directional valve (401) and the first check valve (402) are connected to the outlet of the brake pump. Two ports of the first directional valve (401) are connected to the trailer directional valve (5) and the first check valve (402) respectively, and the other port is connected to a pressure reducing valve (404). The first directional valve (401) and the pressure reducing valve (404) are connected to each other. A second directional valve (403) is connected to the pipeline between them. The second directional valve (403) is connected in parallel with the pressure reducing valve (404). One oil port of the second directional valve (403) is connected to the oil tank, and the control port is connected to one oil port of the first check valve (402). An auxiliary accumulator (10) is also connected between the first check valve (402) and the second directional valve (403). The auxiliary accumulator (10) is connected in parallel with the second directional valve (403). The emergency brake release system is also equipped with an emergency electric pump. A trailer accumulator (8) and a filling valve accumulator (9) are connected in parallel at the oil outlet of the emergency electric pump. The filling valve accumulator (9) is connected to the filling valve. A third reversing valve (7) is connected on the pipeline between the filling valve accumulator (9) and the emergency electric pump. A second check valve (6) is also provided between the trailer accumulator (8) and the filling valve accumulator (9). The second check valve (6) is open from the filling valve accumulator (9) to the trailer accumulator (8).

2. A method for releasing the emergency brake of an underground loader, implemented based on the emergency brake release system for an underground loader as described in claim 1, characterized in that, Including the following operating conditions: Normal operating condition: The trailer reversing valve (5) does not reverse. The brake pump is started. One oil path controls the first reversing valve (401) and the first check valve (402) to reverse and open. The oil at the control end of the second reversing valve (403) is discharged. The other oil path enters the front axle brake (1) and the rear axle brake (2) through the filling valve and the first brake valve (301) in sequence to release the brake. Fault Condition 1: When the brake pump fails, the emergency electric pump is started, and the third reversing valve (7) is energized and reversed. The oil from the emergency electric pump is charged into the accumulator (9) of the charging valve through the third reversing valve (7). After the charging is completed, the third reversing valve (7) is de-energized and returns to its original position. The oil in the accumulator (9) of the charging valve enters the front axle brake (1) and the rear axle brake (2) through the two first brake valves (301) respectively, and the brake is released. Fault Condition 2: When the vehicle cannot move normally, the trailer pulls the trailer hook to reverse the trailer reversing valve (5). The accumulator (9) of the charging valve and the trailer accumulator (8) supply oil together. One path of oil output from the brake pump controls the reversing of the first reversing valve (401). At the same time, the first check valve (402) opens, driving the second reversing valve (403) to reverse and drain oil. Another path of oil enters the front axle brake (1) and the rear axle brake (2) through the charging valve and the first brake valve (301) to release the brake. Fault Condition 3: When the faulty vehicle cannot start, the trailer pulls the trailer hook to reverse the trailer reversing valve (5). The trailer accumulator (8) and the charging valve accumulator (9) supply oil at the same time. The first reversing valve (401) and the first check valve (402) do not operate. After the oil is depressurized by the pressure reducing valve (404), part of it controls the reversing of the first brake valve (301) and the second brake valve (302). The other part enters the front axle brake (1) and the rear axle brake (2) respectively through the two second brake valves (302) to release the brake.

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