Hydraulic service braking system and control method thereof

Abstract

The invention discloses a hydraulic service braking system and a control method thereof, and belongs to the technical field of walking machinery. The hydraulic braking system overcomes the defect that in the prior art, a traditional hydraulic braking system is too large in leakage amount, and braking faults are caused. The main structure of the hydraulic brake system comprises a hydraulic oil power source, a controller and an energy accumulator connected with the hydraulic oil power source, a liquid outlet of the energy accumulator is connected with a foot brake valve and a brake valve set, and oil outlets of the foot brake valve and the brake valve set are connected with a brake through shuttle valves. And the controller is respectively connected with the signal ends of the vehicle speed sensor, the wireless receiver, the pressure sensor and the brake valve group. The invention is mainly applied to walking machinery.

Description

Technical Field

[0001] The invention belongs to the technical field of walking machinery, and particularly relates to a hydraulic vehicle braking system and a control method thereof. Background Art

[0002] When engineering vehicles and agricultural vehicles are operating in cluster operations or high-risk working conditions, the whole vehicle needs to be remotely controlled. The reliability of the vehicle's braking system is crucial for the safety of the vehicle. To improve the braking reliability of the vehicle, full hydraulic braking is often adopted for vehicle braking. Therefore, it is very important to design a reliable and remotely controllable full hydraulic braking circuit and conduct effective control.

[0003] The existing hydraulic braking system at present is based on the original braking foot valve, with a proportional pressure reducing valve connected in parallel. By controlling the pressure output from the proportional pressure reducing valve to the brake, the function of vehicle braking is generated, and a two-position two-way solenoid valve is connected in parallel on the proportional pressure reducing valve to achieve the function of parking braking. However, the deficiencies of the above solution are as follows:

[0004] 1. By using a proportional solenoid valve and a two-position two-way switch valve as the control valve group for vehicle braking and parking braking, generally, the proportional solenoid valve and the two-position two-way switch valve are in the form of spool valves, and the leakage amount is 50 - 150 mL / min. In a braking circuit with an accumulator for oil buffer, a large leakage amount will cause the filling valve to open frequently, wasting energy, and in an emergency, it will also cause braking failures due to excessive leakage.

[0005] 2. Since the braking form uses a proportional pressure reducing valve to output braking pressure, and the proportional pressure reducing valve is relatively expensive, especially for large equipment with a large demand for braking flow, the price is even higher. Therefore, the overall design cost is relatively high. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a hydraulic vehicle braking system and a control method thereof.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0008] A hydraulic vehicle braking system includes a hydraulic oil power source, a controller, and an accumulator connected to the hydraulic oil power source. The liquid outlet of the accumulator is respectively connected to a foot brake valve and a brake valve group. The oil outlets of the foot brake valve and the brake valve group are both connected to a brake through a shuttle valve. The controller is respectively connected to a vehicle speed sensor, a wireless receiver, a pressure sensor, and the signal terminal of the brake valve group.

[0009] Preferably, the brake valve group includes an electromagnetic cone valve 1, an electromagnetic cone valve 2, and a pressure reducing valve. The oil inlet P2 of the electromagnetic cone valve 1 is connected to the accumulator. The oil outlet of the electromagnetic cone valve 1 is respectively connected to the electromagnetic cone valve 2 and the pressure reducing valve. The pressure reducing valve is connected to the shuttle valve. The oil outlet T2 of the electromagnetic cone valve 2 is connected to the fuel tank.

[0010] Preferably, the brake valve group includes a two-position three-way solenoid valve and a pressure reducing valve. The three oil ports of the two-position three-way solenoid valve are respectively connected to the accumulator, the pressure reducing valve, and the fuel tank. The pressure reducing valve is connected to the shuttle valve.

[0011] Preferably, the electromagnetic cone valve 1 and the electromagnetic cone valve 2 are connected to the output port of the controller through a wire harness. The vehicle speed sensor and the pressure sensor are connected to the input port of the controller through a wire harness. The wireless receiver is connected to the controller through a bus. The wireless receiver receives the instructions for grouped operation or the remote control instructions for single actions.

[0012] A control method uses the hydraulic service brake system as described above and includes the following braking modes: manual braking, remote control service braking, remote control emergency braking, and temporary parking braking.

[0013] Preferably, the control method for the manual braking is as follows:

[0014] Under normal conditions, the service brake is defaulted to the non-working state. At this time, the controller outputs a signal to keep the electromagnetic cone valve 1 and the electromagnetic cone valve 2 energized all the time. The electromagnetic cone valve 1 is in the upper position and is in the cut-off state. The electromagnetic cone valve 2 is in the upper position and is in the connected state.

[0015] During manual braking, a person steps on the foot brake valve. The depression stroke of the foot brake valve is positively correlated with the output pressure. At this time, the pressure oil of the accumulator is output from the P1 port of the foot brake valve to the A1 port, enters the shuttle valve of the brake valve group through the P3 port, and finally outputs pressure to the brake through the A2 port to achieve braking. At this time, since the electromagnetic cone valve 1 is in the upper position and is in the cut-off state, the pressure oil of the accumulator cannot enter the brake valve group. When the foot brake valve is released, the oil return of the brake returns to the fuel tank through the shuttle valve and the T1 port of the foot brake valve, or returns to the fuel tank through the shuttle valve, the pressure reducing valve, the upper position of the electromagnetic cone valve 2, and the T2 port.

[0016] Preferably, the control methods for the remote control service braking and the remote control emergency braking are as follows:

[0017] When the wireless receiver receives the service braking or emergency stop braking instruction, it sends it to the controller. The controller outputs a signal to de-energize the electromagnetic cone valve 1 and the electromagnetic cone valve 2. The electromagnetic cone valve 1 is in the lower position and is in the connected state. The electromagnetic cone valve 2 is in the lower position and is in the cut-off state. At this time, the pressure oil of the accumulator enters the lower position of the electromagnetic cone valve 1 through the P2 port, then passes through the pressure reducing valve and the shuttle valve and is output to the A2 port, and finally outputs pressure to the brake to achieve service or emergency braking.

[0018] Preferably, the control method of the temporary parking brake is as follows: when the temporary parking brake is applied, the engine stops and the whole vehicle is powered off. The first electromagnetic cone valve and the second electromagnetic cone valve are de-energized. The first electromagnetic cone valve is in the lower position and in a connected state, and the second electromagnetic cone valve is in the lower position and in a cut-off state. At this time, the pressure oil of the accumulator enters the lower position of the first electromagnetic cone valve through the P2 port, then passes through the pressure reducing valve and the shuttle valve and is output to the A2 port, and finally the output pressure is applied to the brake to achieve the temporary parking brake.

[0019] Preferably, during service braking, since the pressure output by the on-off type first electromagnetic cone valve and second electromagnetic cone valve causes the brake to be applied, which is a step pressure output and will generate a large braking impact. When the vehicle is loaded with materials, there will be a phenomenon of material spillage. By simulating the proportional braking effect, through experimental verification, a better braking effect can be achieved.

[0020] According to the speed of the vehicle, in the jog braking mode, the output braking torque is controlled to control the smoothness of braking. The control method of jog control for service braking is as follows:

[0021] When the remote control braking signal is a proportional signal with an equivalent value of 0 - 1, the braking signal received by the wireless receiver, after being processed by the controller, can simulate and output the jog braking time Δt1, making Δt1 / ΔT a quantity of 0 - 1, so as to obtain an equivalent braking torque coefficient α of 0 - 1 and generate a braking effect equivalent to the proportional output.

[0022] When the braking signal is a full braking signal with an equivalent value of 1, the controller adjusts the jog braking time Δt1 according to the vehicle speed signal of the vehicle speed sensor. When the speed is higher than v1, it outputs a braking torque with an equivalent braking torque coefficient α = 1; when the speed is lower than v1, it outputs an equivalent braking torque M1 with an equivalent braking torque coefficient α < 1; when the speed becomes 0, it outputs an equivalent braking torque M1 with an equivalent braking torque coefficient α = 1. At this time, it is the parking process until the remote braking signal is released. The equivalent braking torque M1 generated during the entire braking process gradually changes from large to small, making the braking process smooth.

[0023] When the braking signal is an emergency braking signal, the controller outputs an equivalent braking torque M1 with an equivalent braking torque coefficient α = 1 until the emergency braking signal is released.

[0024] ΔT = Δt1 + Δt2;

[0025] M1 = k×(Δt1 / ΔT)×M;

[0026] α = k×(Δt1 / ΔT);

[0027] Among them, v1 is the vehicle running speed, Δt1 is the jog braking time, Δt2 is the jog release time, ΔT is the unit braking cycle, M is the full braking torque, M1 is the equivalent braking torque, and α is the equivalent braking torque coefficient.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. Two switch quantities, namely solenoid cone valve 1 and solenoid cone valve 2, are used to replace the proportional valve for braking operation. When the solenoid cone valve 1 and solenoid cone valve 2 are in the cut-off state, the normal leakage is only 3 - 5 drops / min, reducing the leakage of the system and meeting the usage requirements of harsh leakage conditions;

[0030] 2. Based on the braking system using solenoid cone valves, a control strategy for jog control of service braking is proposed, reducing the braking impact caused by solenoid cone valve braking, replacing the proportional pressure reducing valve to output pressure for service braking, with equivalent braking effect and lower cost;

[0031] 3. The present invention is a dual-mode braking system. It can use the foot brake valve for manual braking and the power-off override braking of the brake valve group. Among them, the power-off override braking of the brake valve group can be used as emergency braking, temporary parking braking, and can also achieve smooth service braking, with the advantages of small leakage, low price, and good control mode;

[0032] 4. The present invention supports multiple braking methods, including manual braking, remote control service braking, remote control emergency braking, and temporary parking braking, can adapt to different operation requirements and environmental conditions, and the remote control service braking and remote control emergency braking functions realized through the wireless receiver can quickly respond when the driver cannot react in time, improving the driving safety of the vehicle;

[0033] 5. Adopting the jog braking mode, dynamically adjusting the braking torque according to the vehicle speed, making the whole braking process smoother, reducing the impact caused by sudden braking, protecting the safety of passengers, and at the same time reducing the wear of vehicle components;

[0034] 6. The controller is connected to multiple sensors (such as vehicle speed sensor, pressure sensor, etc.), can monitor the vehicle state in real time, and automatically adjust the braking parameters according to the actual situation to ensure the best braking effect;

[0035] 7. The brake valve group can select different combinations of solenoid cone valves or two-way three-way solenoid valves according to actual needs, increasing the flexibility and adaptability of the system;

[0036] In summary, the present invention not only improves the driving safety and comfort, but also demonstrates a high degree of intelligence and flexibility, and is applicable to various complex operating environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the hydraulic system diagram of the present invention;

[0038] Figure 2 This is the schematic diagram of the brake valve group in Embodiment 2 of the present invention;

[0039] Figure 3 This is the schematic diagram of the brake valve group in Embodiment 3 of the present invention;

[0040] Figure 4 This is the brake logic control flow chart of the present invention;

[0041] Figure 5 This is a schematic diagram of a method in terms of time planning during jog braking of the present invention.

[0042] In the figure: 1, hydraulic oil power source; 2, accumulator; 3, foot brake valve; 4, vehicle speed sensor; 5, wireless receiver; 6, controller; 7, pressure sensor; 8, brake; 9, fuel tank; 10, brake valve group; 101, electromagnetic cone valve 1; 102, electromagnetic cone valve 2; 103, pressure reducing valve; 104, shuttle valve; 105, two-position three-way solenoid valve. Detailed implementation manners

[0043] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0044] Embodiment 1:

[0045] As Figure 1 shown, a hydraulic service brake system includes a hydraulic oil power source 1, a controller 6, and an accumulator 2 connected to the hydraulic oil power source 1. The liquid outlet of the accumulator 2 is respectively connected to a foot brake valve 3 and a brake valve group 10. The oil outlets of the foot brake valve 3 and the brake valve group 10 are both connected to a brake 8 through a shuttle valve 104. The controller 6 is respectively connected to the signal terminals of a vehicle speed sensor 4, a wireless receiver 5, a pressure sensor 7, and the brake valve group 10.

[0046] Among them, the hydraulic oil power source is generally a charge valve group, and the shuttle valve 104 is integrated on the valve body of the brake valve group 10.

[0047] In this embodiment, the hydraulic oil power source 1 supplies oil to the accumulator 2. Generally, when the charge pressure upper limit is reached, the oil supply stops, and the entire brake system brakes relying on the energy temporarily stored in the accumulator 2. Generally, the volume of the accumulator 2 can meet the braking requirements for 3 - 5 full strokes of the brake 8.

[0048] Embodiment 2:

[0049] As Figure 1-2As shown in the figure, a hydraulic service braking system, which is different from that of Embodiment 1 in that the brake valve group 10 includes an electromagnetic cone valve 101, an electromagnetic cone valve 102 and a pressure reducing valve 103. The oil inlet P2 of the electromagnetic cone valve 101 is connected to the accumulator 2, and the oil outlet of the electromagnetic cone valve 101 is respectively connected to the electromagnetic cone valve 102 and the pressure reducing valve 103. The pressure reducing valve 103 is connected to the shuttle valve 104, and the oil outlet T2 of the electromagnetic cone valve 102 is connected to the fuel tank 9.

[0050] Furthermore, the electromagnetic cone valve 101 and the electromagnetic cone valve 102 are connected to the output port of the controller 6 through a wire harness. The vehicle speed sensor 4 and the pressure sensor 7 are connected to the input port of the controller 6 through a wire harness. The wireless receiver 5 is connected to the controller 6 through a bus, and the wireless receiver 5 receives the instructions for grouped operation or the remote control instructions for single actions.

[0051] In this embodiment, the electromagnetic cone valve 101 has a normally closed function, and the electromagnetic cone valve 102 has a normally open function (or the electromagnetic cone valve 101 has a normally open function and the electromagnetic cone valve 102 has a normally closed function. In this case, the braking logic is power-on braking, which is contrary to the logic described in detail in the present invention). The electromagnetic cone valve 101 and the electromagnetic cone valve 102 are linked and lose power or gain power simultaneously. When losing power, the brake valve group 10 outputs pressure to achieve unauthorized braking. The pressure reducing valve 103 sets the reduced pressure to protect the brake 8. The brake valve group 10 and the foot brake valve 3 are connected in parallel, and the pressure is output to the brake 8 through the shuttle valve 104.

[0052] For the used electromagnetic cone valve 101 and electromagnetic cone valve 102, in the cut-off state, the normal leakage rate is only 3-5 drops / min, meeting the use requirements of harsh leakage conditions.

[0053] Embodiment 3:

[0054] As Figure 3 shown in the figure, a hydraulic service braking system, which is different from that of Embodiment 1 in that the brake valve group 10 includes a two-position three-way solenoid valve 105 and a pressure reducing valve 103. The three oil ports of the two-position three-way solenoid valve 105 are respectively connected to the accumulator 2, the pressure reducing valve 103 and the fuel tank 9, and the pressure reducing valve 103 is connected to the shuttle valve 104.

[0055] Embodiment 4:

[0056] A control method uses the hydraulic service braking system as described in Embodiment 2, including the following braking methods: manual braking, remote control service braking, remote control emergency braking and temporary parking braking.

[0057] Furthermore, the control method for manual braking is:

[0058] Under normal conditions, the service brake defaults to the non-operating state. At this time, the controller 6 outputs a signal to keep the electromagnetic cone valve I 101 and the electromagnetic cone valve II 102 energized. The electromagnetic cone valve I 101 is in the upper position and is in the cut-off state, while the electromagnetic cone valve II 102 is in the upper position and is in the connected state;

[0059] During manual braking, the operator steps on the foot brake valve 3. The depression stroke of the foot brake valve 3 is positively correlated with the output pressure. At this time, the pressure oil of the accumulator 2 is output from the P1 port of the foot brake valve 3 to the A1 port, enters the shuttle valve 104 of the brake valve group 10 through the P3 port, and finally outputs pressure to the brake 8 through the A2 port to achieve braking; at this time, since the electromagnetic cone valve I 101 is in the upper position and is in the cut-off state, the pressure oil of the accumulator 2 cannot enter the brake valve group 10; when the foot brake valve 3 is released, the oil return of the brake 8 returns to the fuel tank 9 through the shuttle valve 104 and the T1 port of the foot brake valve 3, or returns to the fuel tank 9 through the shuttle valve 104, the pressure reducing valve 103, the upper position of the electromagnetic cone valve II 102, and the T2 port.

[0060] Furthermore, the control methods for remote control service braking and remote control emergency braking are as follows:

[0061] When the wireless receiver 5 receives a service braking or emergency stop braking instruction, it sends it to the controller 6. The controller 6 outputs a signal to de-energize the electromagnetic cone valve I 101 and the electromagnetic cone valve II 102. The electromagnetic cone valve I 101 is in the lower position and is in the connected state, while the electromagnetic cone valve II 102 is in the lower position and is in the cut-off state. At this time, the pressure oil of the accumulator 2 enters the lower position of the electromagnetic cone valve I 101 through the P2 port, then passes through the pressure reducing valve 103 and the shuttle valve 104 and is output to the A2 port, and finally outputs pressure to the brake 8 to achieve service or emergency braking.

[0062] Furthermore, the control method for temporary parking braking is as follows: When performing temporary parking braking, the engine stops and the whole vehicle is powered off. The electromagnetic cone valve I 101 and the electromagnetic cone valve II 102 are in the de-energized state. The electromagnetic cone valve I 101 is in the lower position and is in the connected state, while the electromagnetic cone valve II 102 is in the lower position and is in the cut-off state. At this time, the pressure oil of the accumulator 2 enters the lower position of the electromagnetic cone valve I 101 through the P2 port, then passes through the pressure reducing valve 103 and the shuttle valve 104 and is output to the A2 port, and finally outputs pressure to the brake 8 to achieve temporary parking braking. Due to the existence of leakage, this parking braking is temporary, and as the pressure of the accumulator 2 leaks, the parking braking fails.

[0063] Furthermore, during service braking, since the pressure output by the on-off electromagnetic cone valve I 101 and the electromagnetic cone valve II 102 brakes the brake 8, which is a step pressure output, it will generate a large braking impact. When the vehicle is loaded with materials, there will be a phenomenon of material spillage. By simulating the proportional braking effect, through experimental verification, a better braking effect can be achieved;

[0064] According to the speed of the vehicle, the braking torque is controlled in the jog braking mode to control the smoothness of braking. For example, Figure 4 As shown, the control method for jog control of service braking is as follows:

[0065] When the remote control braking signal is a proportional signal with an equivalent value of 0 - 1, the braking signal received by the wireless receiver 5 is processed by the controller 6, and the jog braking time Δt1 can be output analogously, making Δt1 / ΔT a quantity of 0 - 1, so as to obtain an equivalent braking torque coefficient α of 0 - 1 and produce a braking effect equivalent to the proportional output;

[0066] When the braking signal is a full braking signal with an equivalent value of 1, the controller 6 adjusts the jog braking time Δt1 according to the vehicle speed signal of the vehicle speed sensor 4. When the speed is higher than v1, a braking torque with an equivalent braking torque coefficient α = 1 is output; when the speed is less than v1, an equivalent braking torque M1 with an equivalent braking torque coefficient α < 1 is output; when the speed becomes 0, an equivalent braking torque M1 with an equivalent braking torque coefficient α = 1 is output. At this time, it is the parking process until the remote braking signal is released. The equivalent braking torque M1 generated during the entire braking process gradually changes from large to small, making the braking process smooth;

[0067] When the braking signal is an emergency braking signal, the controller 6 outputs an equivalent braking torque M1 with an equivalent braking torque coefficient α = 1 until the emergency braking signal is released;

[0068] ΔT = Δt1 + Δt2;

[0069] M1 = k×(Δt1 / ΔT)×M;

[0070] α = k×(Δt1 / ΔT);

[0071] Among them, v1 is the vehicle running speed, unit m / s, Δt1 is the jog braking time, unit s, Δt2 is the jog release time, unit s, ΔT is the unit braking cycle, M is the full braking torque, unit N·m, M1 is the equivalent braking torque, unit N·m, and α is the equivalent braking torque coefficient.

[0072] For example, Figure 5 As shown, within a full braking cycle, it contains several unit braking cycles:

[0073] T = ΔT1 + ΔT2 + ΔT3 + ……

[0074] To make the control program more concise, the unit braking cycle is generally set as:

[0075] ΔT1 = ΔT2 = ΔT3 = ……

[0076] The unit braking cycle time ΔT can be selected as 0.5 s, 1.5 s, 2 s, etc. respectively according to factors such as vehicle weight, road surface friction coefficient, and braking torque magnitude.

Claims

1. A hydraulic service brake system, comprising a hydraulic oil power source (1), a controller (6) and an accumulator (2) connected to the hydraulic oil power source (1), characterized in that: The liquid outlet of the accumulator (2) is respectively connected to the foot brake valve (3) and the brake valve group (10); the oil outlets of the foot brake valve (3) and the brake valve group (10) are connected to the brake (8) via a shuttle valve (104); and the controller (6) is respectively connected to the vehicle speed sensor (4), the wireless receiver (5), the pressure sensor (7) and the signal end of the brake valve group (10).

2. The hydraulic service brake system according to claim 1, characterized in that: The brake valve group (10) comprises an electromagnetic cone valve (101), an electromagnetic cone valve (102) and a pressure reducing valve (103); an oil inlet P2 of the electromagnetic cone valve (101) is connected to an accumulator (2); an oil outlet of the electromagnetic cone valve (101) is respectively connected to the electromagnetic cone valve (102) and the pressure reducing valve (103); the pressure reducing valve (103) is connected to a shuttle valve (104); and an oil outlet T2 of the electromagnetic cone valve (102) is connected to an oil tank (9).

3. The hydraulic service brake system according to claim 1, characterized in that: The brake valve group (10) comprises a two-position three-way solenoid valve (105) and a pressure reducing valve (103); three oil ports of the two-position three-way solenoid valve (105) are respectively connected to the accumulator (2), the pressure reducing valve (103) and the oil tank (9); and the pressure reducing valve (103) is connected to the shuttle valve (104).

4. The hydraulic service brake system according to claim 2, characterized in that: The electromagnetic cone valve 1 (101) and the electromagnetic cone valve 2 (102) are connected to the output port of the controller (6) through a wiring harness, the vehicle speed sensor (4) and the pressure sensor (7) are connected to the input port of the controller (6) through a wiring harness, and the wireless receiver (5) is connected to the controller (6) through a bus, and the wireless receiver (5) receives cluster operation instructions or single action remote control instructions.

5. A control method, using the hydraulic service brake system according to claim 2, characterized in that: Includes the following braking methods: manual braking, remote control service braking, remote control emergency braking and temporary parking braking.

6. The control method according to claim 5, characterized in that: The control method of the artificial brake is: Under normal conditions, the service brake is in a non-working state by default. At this time, the controller (6) outputs a signal so that the electromagnetic cone valve 1 (101) and the electromagnetic cone valve 2 (102) are always energized. The electromagnetic cone valve 1 (101) is in the upper position, which is a cut-off state, and the electromagnetic cone valve 2 (102) is in the upper position, which is a connected state. During manual braking, the foot brake valve (3) is manually stepped on, and the stepping stroke of the foot brake valve (3) is positively correlated with the output pressure. At this time, the pressure oil of the accumulator (2) is output to the A1 port through the P1 port of the foot brake valve (3), enters the shuttle valve (104) of the brake valve group (10) through the P3 port, and finally outputs the pressure to the brake (8) through the A2 port to achieve braking. At this time, since the electromagnetic cone valve (101) is in the upper position and is in the cut-off state, the pressure oil of the accumulator (2) cannot enter the brake valve group (10). When the foot brake valve (3) is released, the return oil of the brake (8) returns to the oil tank (9) through the shuttle valve (104) and the T1 port of the foot brake valve (3), or returns to the oil tank (9) through the shuttle valve (104), the pressure reducing valve (103), the upper position of the electromagnetic cone valve (102), and the T2 port.

7. The control method according to claim 6, characterized in that: The control method of the remote control service brake and remote control emergency brake is: When the wireless receiver (5) receives a driving brake or emergency brake command, it sends it to the controller (6). The controller (6) outputs a signal to de-energize the electromagnetic cone valve 1 (101) and the electromagnetic cone valve 2 (102). The electromagnetic cone valve 1 (101) is in the lower position, which is a connected state. The electromagnetic cone valve 2 (102) is in the lower position, which is a cut-off state. At this time, the pressure oil of the accumulator (2) enters the lower position of the electromagnetic cone valve 1 (101) through the P2 port, and then passes through the pressure reducing valve (103) and the shuttle valve (104) to be output to the A2 port, and finally outputs the pressure to the brake (8), thereby realizing driving or emergency braking.

8. The control method according to claim 6, characterized in that: The control method of the temporary parking brake is as follows: when the temporary parking brake is applied, the machine is shut down and the whole vehicle is powered off, the electromagnetic cone valve 1 (101) and the electromagnetic cone valve 2 (102) are in a power-off state, the electromagnetic cone valve 1 (101) is in a lower position, which is a connected state, and the electromagnetic cone valve 2 (102) is in a lower position, which is a cut-off state. At this time, the pressure oil of the accumulator (2) enters the lower position of the electromagnetic cone valve 1 (101) through the P2 port, and then passes through the pressure reducing valve (103) and the shuttle valve (104) to be output to the A2 port, and finally outputs the pressure to the brake (8), thereby realizing the temporary parking brake.

9. The control method according to claim 5, characterized in that: According to the speed of the vehicle, the output braking torque is controlled by the inching braking mode, thereby controlling the stability of the braking. The control method of inching control of the vehicle braking is: When the remote control brake signal is a proportional signal with an equivalent value of 0-1, the brake signal received by the wireless receiver (5) is processed by the controller (6) to output a simulated output of the inching brake time Δt1, so that Δt1 / ΔT is a quantity of 0-1, so that an equivalent braking torque coefficient α is obtained of 0-1, and a braking effect equivalent to the proportional output is produced; When the braking signal is a complete braking signal with an equivalent of 1, the controller (6) adjusts the inching braking time Δt1 according to the vehicle speed signal of the vehicle speed sensor (4), and when the speed is higher than v1, outputs a braking torque with an equivalent braking torque coefficient α=1; when the speed is lower than v1, outputs an equivalent braking torque M1 with an equivalent braking torque coefficient α<1; When the speed becomes 0, the equivalent braking torque M1 with the equivalent braking torque coefficient α=1 is output. This is the parking process until the remote brake signal is released. The equivalent braking torque M1 generated during the entire braking process is gradually increasing from large to small, making the braking process smooth. When the brake signal is an emergency brake signal, the controller (6) outputs an equivalent brake torque M1 with an equivalent brake torque coefficient α=1 until the emergency brake signal is released; ΔT = Δt1 + Δt2; M1=k×(Δt1 / ΔT)×M; α=k×(Δt1 / ΔT); Among them, v1 is the vehicle speed, Δt1 is the inching braking time, Δt2 is the inching release time, ΔT is the unit braking cycle, M is the full braking torque, M1 is the equivalent braking torque, and α is the equivalent braking torque coefficient.

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