Auxiliary drive brake control system and method for boom type aerial work platform

Abstract

The invention discloses an auxiliary driving and braking control system and method for an arm support type aerial work platform. The auxiliary driving and braking control system comprises a hydraulic oil tank, a driving device, a main control valve, a working hydraulic system, a walking control valve, a braking electromagnetic valve, a walking hydraulic motor, a walking driving system and a system controller assembly. The walking control valve and the main control valve are connected in parallel through a hydraulic pipeline, and composite linkage of the working hydraulic system and the walking hydraulic system is achieved. The system controller assembly comprises a system controller and a sensor assembly, the system controller controls the walking control valve and the braking electromagnetic valve according to data information measured by the sensor assembly, and the walking driving system comprises a driving motor and a speed reducer. By adding the braking electromagnetic valve and the control method under the related posture, the auxiliary driving motor side has the same braking effect as a brake, it is guaranteed that the whole machine can normally stop on a slope and does not slip on the slope, and the walking braking performance of the whole machine is improved.

Description

Technical Field

[0001] The invention relates to an auxiliary driving and braking control system and method for an arm-type aerial work platform, belonging to the technical field of aerial work platforms. Background Art

[0002] The braking technology of boom-type aerial work platforms on slopes mainly relies on hydraulic braking systems, mechanical braking systems and electronic auxiliary braking systems. The hydraulic braking system transmits braking force through hydraulic pumps and hydraulic cylinders, and has the characteristics of fast response speed and large braking force; the mechanical braking system achieves braking through friction plates or brake discs, with a simple structure and high reliability; the electronic auxiliary braking system combines sensors and controllers, and can automatically adjust the braking force according to the slope angle and platform load. These technologies meet the braking needs of boom-type aerial work platforms on slopes to a certain extent.

[0003] The driving form of aerial work platforms is relatively mature, among which electric-hydraulic hybrid drive is favored due to its unique technical route and economic benefits. Its main technical features are: when traveling at high and low speeds on flat ground, due to the small driving resistance of the whole machine, the rear axle travel motor is usually used for two-wheel drive, and the front axle tire travel hydraulic motor does not provide driving force; when climbing a slope or when the driving resistance increases, it switches to four-wheel drive, and the travel hydraulic motor and the travel motor jointly provide driving force. However, in the prior art, the hydraulic travel motor only provides driving force and does not have a braking function, resulting in the entire machine braking completely relying on the rear axle drive motor. This will result in poor braking effect or the whole machine sliding downhill in certain special postures, posing a safety hazard. Summary of the invention

[0004] Purpose of the invention: In view of the deficiencies in the prior art, the present invention provides an auxiliary drive braking control system and method for a boom-type aerial work platform, which solves the problem of no braking force on the driving hydraulic motor side of the boom-type aerial work platform in the four-wheel drive mode. By adding a brake solenoid valve and a control method under related postures, the auxiliary drive motor side has the same braking effect as the brake, ensuring that the entire machine can park normally on a slope without sliding, thereby improving the walking braking performance of the entire machine.

[0005] Technical solution: An auxiliary drive brake control system for a boom-type aerial work platform, including a hydraulic oil tank, a drive device, a hydraulic pump, a main control valve, a working hydraulic system, a travel control valve, a brake solenoid valve, a travel hydraulic motor, a travel drive system and a system controller assembly; The main control valve is connected to the travel control valve through a hydraulic pipeline. The driving device drives the hydraulic pump to rotate to take oil from the hydraulic oil tank. The hydraulic oil enters the oil inlet P of the main control valve and the oil inlet P of the travel control valve through a hydraulic hose. The LS port of the travel control valve and the LS port of the main control valve are connected through a hydraulic pipeline. The working hydraulic system controls and distributes hydraulic oil through the main control valve; The travel hydraulic motor includes a right motor and a left motor respectively connected to the right tire and the left tire of the front axle assembly of the whole machine; the brake solenoid valve includes a first brake solenoid valve and a second brake solenoid valve arranged on the oil circuit between the oil ports A and B on both sides of the right motor and the travel control valve; and also includes a third brake solenoid valve and a fourth brake solenoid valve arranged on the oil circuit between the oil ports A and B on both sides of the left motor and the travel control valve; The oil ports FRA, FRB, FLA and FLB of the travel control valve are respectively connected to the first brake solenoid valve, the second brake solenoid valve, the third brake solenoid valve and the fourth brake solenoid valve through hydraulic pipelines; The system controller assembly includes a system controller and a sensor assembly. The system controller controls the brake solenoid valve and the travel system according to the data information measured by the sensor assembly.

[0006] The present invention sets a brake solenoid valve and a sensor assembly, and judges the current vehicle posture through the vehicle posture data fed back by the sensor assembly. The system controller gives corresponding control according to the preset program, so that one side of the travel hydraulic motor has the same braking effect as the brake, ensuring that the whole machine can stop normally on the slope without slipping, and improving the travel braking performance of the whole machine. Through the intervention of the brake solenoid valve, the travel hydraulic motor can quickly decelerate when stopping, reduce the mechanical impact and wear caused by inertia, and extend the service life of the travel hydraulic motor. At the same time, the brake solenoid valve can quickly respond to the control signal, realize the instant braking of the travel hydraulic motor, improve the dynamic response performance of the system, and is suitable for working conditions that require rapid braking. It can also effectively prevent the travel hydraulic motor from continuing to idle after the oil supply is stopped, reduce unnecessary energy loss, thereby reducing the overall energy consumption of the system and improving energy utilization efficiency.

[0007] The travel control valve comprises a three-position four-way solenoid reversing valve and a flow-dividing and collecting valve. The three-position four-way solenoid reversing valve is provided with electromagnets Y1 and Y2 controlled by a system controller. The oil inlet of the three-position four-way solenoid reversing valve is connected with the oil inlet P of the main control valve and the oil outlet of the hydraulic pump. The three-position four-way solenoid reversing valve has two oil outlets, one of which is connected with the two oil ports FRB and FLA of the travel control valve, and the other is connected with the oil inlet of the flow-dividing and collecting valve. A shuttle valve is provided between the hydraulic pipelines connected to the two oil outlets of the three-position four-way solenoid reversing valve, the oil outlet of the shuttle valve is connected to the load-sensitive oil port LS of the travel control valve through the hydraulic pipeline, and a first one-way valve whose oil inlet is connected to the oil outlet of the shuttle valve is provided on the pipeline; It also includes a second one-way valve, a third one-way valve and a fourth one-way valve connected with the oil inlet and the oil return port T of the travel control valve through a hydraulic pipeline, wherein the second one-way valve and the third one-way valve are respectively arranged on the hydraulic pipeline between the two oil outlets of the flow dividing and collecting valve and the oil return port T of the travel control valve, and the fourth one-way valve is arranged on the hydraulic pipeline between the hydraulic pipeline connected with the three-position four-way solenoid reversing valve and the oil ports FRB and FLA and the oil return port T of the travel control valve; A throttle valve whose two ends are connected to the oil outlet pipeline of the flow-dividing and collecting valve is arranged between the two oil outlets of the flow-dividing and collecting valve.

[0008] The three-position four-way solenoid reversing valve is used to control the power output direction of the vehicle forward or backward. At the same time, it can realize the reverse thrust of the travel hydraulic motor when driving on a slope to slow down the vehicle; the diverter and collector valve can balance the oil inlet at both ends and distribute the power evenly, making the driving and braking states stable.

[0009] Any of the brake solenoid valves comprises a two-position two-way two-way stop valve, on which an electromagnet Y3 controlled by a system controller is disposed, and a filter is disposed between the two-position two-way two-way stop valve and the oil inlet of the brake solenoid valve.

[0010] The filter can filter impurities in the hydraulic oil entering the brake solenoid valve, reduce the failure rate of the brake solenoid valve, and improve the working stability of the whole machine.

[0011] The two-position, two-way, two-way stop valve is provided with a valve core displacement sensor, and the valve core displacement sensor is connected to the system controller via a signal harness.

[0012] As a more preferred option, the use of a brake solenoid valve with a valve core displacement sensor can more accurately understand whether the brake solenoid valve is in place. When the brake solenoid valve core does not move according to the command, it proves that the brake solenoid valve is faulty and can remind the operator to repair it in time.

[0013] The first overflow valve, the second overflow valve, the third overflow valve and the fourth overflow valve are respectively arranged on the hydraulic pipelines connecting the first brake solenoid valve, the second brake solenoid valve, the third brake solenoid valve and the fourth brake solenoid valve with the left motor and the right motor, and the return oil ports of the first overflow valve, the second overflow valve, the third overflow valve and the fourth overflow valve are connected to the hydraulic oil tank.

[0014] In order to protect the safety of the hydraulic system and reduce the damage caused by increased oil circuit pressure due to failure of some hydraulic components, an overflow valve is provided on the hydraulic pipeline connected to the travel hydraulic motor to protect the oil circuit when the travel hydraulic motor performs deceleration or parking actions.

[0015] The main control valve comprises a multi-valve for providing hydraulic oil distribution for the working hydraulic system; It also includes a load-sensitive valve arranged between the oil inlet pipeline and the oil outlet pipeline of the main control valve, the load-sensitive valve is connected to the load-sensitive oil port LS of the main control valve, and the load-sensitive oil port LS of the main control valve is connected to the load-sensitive oil port of the travel control valve through a hydraulic pipeline; a fifth overflow valve is also arranged between the oil inlet pipeline and the oil outlet pipeline of the main control valve.

[0016] An auxiliary driving and braking control method for a boom-type aerial work platform includes a travel driving system and a sensor assembly installed on a turntable of the whole machine; The sensor assembly includes an inclination sensor and a travel detection switch, and the inclination sensor is connected to the system controller through a signal harness; The travel drive system includes two travel motors connected to the left and right tires of the rear axle of the whole machine through a travel reducer, and also includes a travel control system for controlling the travel motors; The travel control system includes a travel control handle, an enable switch and a travel mode switch. When the travel mode switch is switched to the four-wheel climbing gear drive mode, the enable switch is triggered and the travel control handle is operated at the same time. At this time, the system controller controls the drive device to rotate at a set speed, and the hydraulic pump oil supplies oil to the travel motor through the travel control valve and the brake solenoid valve; The travel mode switch includes flat ground gear and climbing gear; The specific control method includes the following steps: Step 1: The travel mode switch of the whole machine is in the flat gear position. The vehicle is driving on a flat road section. Press the enabling switch to operate the travel control handle to control the whole machine to move forward or backward. The brake solenoid valve is energized, and the inlet and outlet oil of the travel hydraulic motor are connected in the travel control valve. When the whole machine starts to stop moving, the travel motor generates braking torque. When the travel control handle returns to the center position, the electromagnet Y3 on the brake solenoid valve loses power, and the oil circuit of the travel hydraulic motor is disconnected, thus forming a hydrostatic brake. Step 2: When the travel mode switch of the whole machine is in the flat ground gear and the vehicle is traveling on a slope, the vehicle posture is detected by the turntable position stroke detection switch and the inclination sensor set on the chassis of the whole machine, and the hydraulic pump is controlled by the system controller to supply oil to the travel control valve in the opposite direction of the travel hydraulic motor rotation, so that the travel hydraulic motor generates travel resistance; Step 3: The travel mode switch of the whole machine is in the climbing gear. When the vehicle is driving on a flat road, press the enabling switch to operate the travel control handle to control the whole machine to move forward or backward. At this time, the brake solenoid valve is energized, and the travel control valve is energized. At this time, the driving force of the whole machine is provided by the travel motor and the travel hydraulic motor. When the whole machine starts to move, the system controller controls the hydraulic pump to supply oil to the travel control valve to the travel hydraulic motor along the direction of wheel movement. When the whole machine starts to stop moving, the travel motor generates braking torque. When the travel control handle returns to the center position, the travel control valve and the electromagnet Y3 of the brake solenoid valve lose power, and the oil circuit of the travel hydraulic motor is disconnected, thereby forming a hydrostatic brake. Step 4. When the travel mode switch of the whole machine is in the climbing gear and the vehicle is traveling on a slope, the vehicle posture is detected according to the turntable position stroke detection switch and the inclination sensor installed on the chassis of the whole machine. The system controller controls the hydraulic pump to supply oil to the travel control valve in the opposite direction of the rotation of the travel hydraulic motor, so that the travel hydraulic motor generates travel resistance.

[0017] The step 2 is specifically as follows: Step 2.1, detect whether the whole machine counterweight and the front axle of the vehicle are in the same direction according to the turntable position travel detection switch set on the whole machine chassis; Step 2.2: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of α ( ) starts to go downhill. At this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve loses power, and the electromagnet Y2 is energized. The system controller controls the hydraulic pump to supply oil to the travel control valve in the opposite direction of the travel hydraulic motor. The travel hydraulic motor generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process and preventing it from slipping. Step 2.3: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -α ( ) starts to go downhill, at this time, the solenoid Y1 of the three-position four-way solenoid reversing valve loses power, the solenoid Y2 is energized, and the system controller controls the hydraulic pump to supply oil to the travel control valve in the opposite direction of the travel hydraulic motor rotation. The travel hydraulic motor generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process and preventing slipping.

[0018] The step 4 is specifically as follows: Step 4.1: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of α ( ) starts to go downhill. At this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve loses power, and the electromagnet Y2 is energized. The system controller controls the hydraulic pump to supply oil to the travel control valve in the opposite direction of the travel hydraulic motor. The travel hydraulic motor generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process and preventing it from slipping. Step 4.2: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of β ( ) starts to go downhill on a slope. When the whole machine starts to move, the brake solenoid valve is energized, the travel control valve is de-energized, and the valve core returns to the middle position, so that the inlet and outlet oil of the travel hydraulic motor is in the travel control valve, and the oil circuit is connected. The travel hydraulic motor does not provide driving force; When the whole machine stops moving, the travel motor generates braking torque. When the travel control handle returns to the center position, the electromagnet Y3 of the brake solenoid valve loses power, the oil circuit of the travel hydraulic motor is disconnected, and static hydraulic braking is formed. Step 4.3: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -α ( ) starts to go downhill. At this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve loses power, and the electromagnet Y2 is energized. The system controller controls the hydraulic pump to supply oil to the travel control valve in the opposite direction of the travel hydraulic motor. The travel hydraulic motor generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process and preventing it from slipping. Step 4.4: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -β ( ) starts to go downhill on a slope. When the whole machine starts to move, the brake solenoid valve is energized, the travel control valve is de-energized, and the valve core returns to the middle position, so that the inlet and outlet oil of the travel hydraulic motor is in the travel control valve, and the oil circuit is connected. The hydraulic travel motor does not provide driving force; When the whole machine stops moving, the travel motor generates braking torque. When the travel control handle returns to the center position, the electromagnet Y3 of the brake electromagnet loses power, the oil circuit of the travel hydraulic motor is disconnected, and hydrostatic braking is formed.

[0019] Beneficial effects: The present invention sets a brake solenoid valve and a sensor assembly, and judges the current vehicle posture through the vehicle posture data fed back by the sensor assembly. The system controller gives corresponding control according to the preset program, so that one side of the travel hydraulic motor has the same braking effect as the brake, ensuring that the whole machine can stop normally on the slope without slipping, thereby improving the travel braking performance of the whole machine. Through the intervention of the brake solenoid valve, the travel hydraulic motor can quickly decelerate when stopping, reducing the mechanical impact and wear caused by inertia, and extending the service life of the travel hydraulic motor. At the same time, the brake solenoid valve can quickly respond to the control signal, realize the instant braking of the travel hydraulic motor, improve the dynamic response performance of the system, and is suitable for working conditions that require rapid braking. It can also effectively prevent the travel hydraulic motor from continuing to idle after the oil supply is stopped, reducing unnecessary energy loss, thereby reducing the overall energy consumption of the system and improving energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 It is the hydraulic principle diagram of the present invention.

[0022] Figure 2 This is a partial hydraulic principle diagram of the present invention.

[0023] Figure 3 This is the brake solenoid valve of the present invention.

[0024] Figure 4 The invention discloses a brake solenoid valve with a valve core displacement sensor.

[0025] Figure 5 This is a diagram of the installation structure of the drive structure and the inclination sensor of the present invention, wherein the travel detection switch is integrally connected to the upper structure of the vehicle revolving platform and slides on the revolving platform to detect the rotational travel, which is omitted in the figure.

[0026] Figure 6 The figure is a communication schematic diagram of the sensor assembly and the travel control system of the present invention.

[0027] Figure 7 This is a logic diagram of the control method of the present invention.

[0028] Figure 8 This is a state diagram of the vehicle of the present invention when the counterweight and the front axle are in the same direction and the vehicle is descending at an inclination angle of θ.

[0029] Fig. 9 This is a state diagram of the vehicle of the present invention when the counterweight and the front axle are not in the same direction and the vehicle is descending at a -θ inclination angle.

[0030] Fig.10 This is a state diagram of the vehicle of the present invention when the counterweight and the front axle are in the same direction and the vehicle is descending a slope at an inclination angle of γ.

[0031] Fig.11 This is a state diagram of the vehicle of the present invention when the counterweight and the front axle are not in the same direction and the vehicle is descending at a -γ inclination angle. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] like Figures 1 to 4 As shown, an auxiliary drive brake control system for a boom-type aerial work platform includes a hydraulic oil tank 1, a drive device 2, a hydraulic pump 3, a main control valve 4, a working hydraulic system 5, a travel control valve 6, a brake solenoid valve 7, a travel hydraulic motor 8, a travel drive system 9 and a system controller assembly 10; The main control valve 4 is connected to the travel control valve 6 through a hydraulic pipeline. The driving device 2 drives the hydraulic pump 3 to rotate to take oil from the hydraulic oil tank 1. The hydraulic oil enters the oil inlet P of the main control valve 4 and the oil inlet P of the travel control valve 6 through a hydraulic hose. The LS port of the travel control valve 6 and the LS port of the main control valve 4 are connected through a hydraulic pipeline. The working hydraulic system 5 controls and distributes the hydraulic oil through the main control valve 4; The travel hydraulic motor 8 includes a right motor and a left motor respectively connected to the right tire and the left tire of the front axle assembly of the whole machine; the brake solenoid valve 7 includes a first brake solenoid valve 71 and a second brake solenoid valve 72 arranged on the oil circuit between the oil ports A and B on both sides of the right motor and the travel control valve 6; and also includes a third brake solenoid valve 73 and a fourth brake solenoid valve 74 arranged on the oil circuit between the oil ports A and B on both sides of the left motor and the travel control valve 6; The oil ports FRA, FRB, FLA and FLB of the travel control valve 6 are respectively connected to the first brake solenoid valve 71, the second brake solenoid valve 72, the third brake solenoid valve 73 and the fourth brake solenoid valve 74 through hydraulic pipelines; The system controller assembly 10 includes a system controller 101 and a sensor assembly 102 . The system controller 101 controls the brake solenoid valve 7 and the travel system according to the data information measured by the sensor assembly 102 .

[0036] The present invention sets a brake solenoid valve 7 and a sensor assembly 102, and judges the current vehicle posture through the vehicle posture data fed back by the sensor assembly 102. The system controller 101 gives corresponding control according to the preset program, so that one side of the travel hydraulic motor 8 has the same braking effect as the brake, ensuring that the whole machine can stop normally on the slope without slipping, and improving the travel braking performance of the whole machine. Through the intervention of the brake solenoid valve 7, the travel hydraulic motor 8 can quickly decelerate when stopping, reduce the mechanical impact and wear caused by inertia, and extend the service life of the travel hydraulic motor 8. At the same time, the brake solenoid valve 7 can quickly respond to the control signal, realize the instant braking of the travel hydraulic motor 8, improve the dynamic response performance of the system, and is suitable for working conditions that require rapid braking.

[0037] The travel control valve 6 includes a three-position four-way solenoid reversing valve 61 and a flow dividing and collecting valve 62. The three-position four-way solenoid reversing valve 61 is provided with electromagnets Y1 and Y2 controlled by the system controller 101. The oil inlet of the three-position four-way solenoid reversing valve 61 is connected with the oil inlet P of the main control valve 4 and the oil outlet of the hydraulic pump 3. The three-position four-way solenoid reversing valve 61 has two oil outlets, one of which is connected with the two oil ports FRB and FLA of the travel control valve 6, and the other oil outlet is connected with the oil inlet of the flow dividing and collecting valve 62. A shuttle valve 63 is provided between the hydraulic pipelines connected to the two oil outlets of the three-position four-way solenoid reversing valve 61, the oil outlet of the shuttle valve 63 is connected to the load-sensitive oil port LS of the travel control valve 6 through the hydraulic pipeline, and a first check valve 64 whose oil inlet is connected to the oil outlet of the shuttle valve 63 is provided on the pipeline; It also includes a second one-way valve 65, a third one-way valve 66 and a fourth one-way valve 67 connected with the oil inlet and the oil return port T of the travel control valve 6 through a hydraulic pipeline. The second one-way valve 65 and the third one-way valve 66 are respectively arranged on the hydraulic pipeline between the two oil outlets of the flow dividing and collecting valve 62 and the oil return port T of the travel control valve 6, and the fourth one-way valve 67 is arranged on the hydraulic pipeline between the hydraulic pipeline connected with the three-position four-way solenoid reversing valve 61 and the oil ports FRB and FLA and the oil return port T of the travel control valve 6; A throttle valve 68 is provided between the two oil outlets of the flow-dividing and combining valve 62 , and its two ends are connected to the oil outlet pipelines of the flow-dividing and combining valve 62 .

[0038] The three-position four-way electromagnetic reversing valve 61 is used to control the power output direction of the vehicle forward or backward. At the same time, it can realize the reverse thrust of the travel hydraulic motor 8 when driving on a slope, thereby slowing down the vehicle; the diverter and collector valve 62 can balance the oil intake at both ends and distribute the power evenly, so that the driving state and braking state are stable; the throttle valve 68 is used to control the oil flow stability in the hydraulic pipeline.

[0039] Any of the brake solenoid valves 7 includes a two-position, two-way, two-way stop valve 75 , on which an electromagnet Y3 controlled by the system controller 101 is disposed, and a filter screen 76 is disposed between the two-position, two-way, two-way stop valve 75 and the oil inlet of the brake solenoid valve 7 .

[0040] The filter screen 76 can filter impurities in the hydraulic oil entering the brake solenoid valve 7, reduce the failure rate of the brake solenoid valve 7, and improve the working stability of the whole machine.

[0041] The two-position two-way two-way stop valve 75 is provided with a valve core displacement sensor 77 , and the valve core displacement sensor 77 is connected to the system controller 101 through a signal harness.

[0042] As a more preferred option, using a brake solenoid valve 7 with a valve core displacement sensor 77 can more accurately understand whether the brake solenoid valve 7 is in place. When the valve core of the brake solenoid valve 7 does not move according to the instruction, it proves that the brake solenoid valve 7 is faulty and can remind the operator to repair it in time.

[0043] The first overflow valve 11, the second overflow valve 12, the third overflow valve 13 and the fourth overflow valve 14 are respectively provided on the hydraulic pipeline connecting the first brake solenoid valve 71, the second brake solenoid valve 72, the third brake solenoid valve 73 and the fourth brake solenoid valve 74 with the left motor and the right motor, and the return oil ports of the first overflow valve 11, the second overflow valve 12, the third overflow valve 13 and the fourth overflow valve 14 are connected to the hydraulic oil tank 1.

[0044] In order to protect the safety of the hydraulic system and reduce the damage caused by increased oil circuit pressure due to failure of some hydraulic components, an overflow valve is provided on the hydraulic pipeline connected to the travel hydraulic motor 8 to protect the oil circuit when the travel hydraulic motor 8 performs deceleration or parking actions.

[0045] The main control valve 4 includes a multi-valve for providing hydraulic oil distribution for the working hydraulic system 5; it also includes a load-sensitive valve 41 arranged between the oil inlet pipeline and the oil outlet pipeline of the main control valve 4, and the load-sensitive valve 41 is connected to the load-sensitive oil port LS of the main control valve 4, and the load-sensitive oil port LS of the main control valve 4 is connected to the load-sensitive oil port of the travel control valve 6 through a hydraulic pipeline; a fifth overflow valve 42 is also arranged between the oil inlet pipeline and the oil outlet pipeline of the main control valve 4.

[0046] An auxiliary driving and braking control method for a boom-type aerial work platform includes a travel driving system 9 and a sensor assembly 102 installed on a turntable of the whole machine; The sensor assembly 102 includes an inclination sensor 1021 and a travel detection switch 1022, and the inclination sensor 1021 and the travel detection switch 1022 are connected to the system controller 101 through a signal harness; The travel drive system 9 includes two travel motors 92 connected to the left and right tires of the rear axle of the whole machine through a travel reducer 91, and also includes a travel control system 93 for controlling the travel motors 92; The travel control system 93 includes a travel control handle 931, an enable switch 932 and a travel mode switch 933. When the travel mode switch 933 is switched to the four-wheel climbing gear drive mode, the enable switch 932 is triggered and the travel control handle 931 is operated at the same time. At this time, the system controller 101 controls the drive device 2 to rotate at the set speed, and the oil of the hydraulic pump 3 supplies oil to the travel motor through the travel control valve 6 and the brake solenoid valve 7. The walking mode switch 933 includes a flat ground gear and a climbing gear; Example

[0047] The specific control method includes the following steps: Step 1: The whole machine travel mode switch 933 is in the flat ground gear position, the vehicle is traveling on a flat road section, the enabling switch 932 is pressed to operate the travel control handle 931 to control the whole machine to move forward or backward, the brake solenoid valve 7 is energized, and the oil inlet and outlet of the travel hydraulic motor 8 are connected in the travel control valve 6; When the whole machine starts to stop moving, the travel motor 92 generates a braking torque. When the travel control handle 931 completely returns to the middle position, the electromagnet Y3 on the brake solenoid valve 7 loses power, and the oil circuit of the travel hydraulic motor 8 is disconnected, thereby forming a hydrostatic brake. Step 2: When the whole machine travel mode switching switch 933 is in the flat ground gear position and the vehicle is traveling on a slope, the vehicle posture is detected according to the turntable position travel detection switch 1022 and the inclination sensor 1021 arranged on the whole machine chassis, and the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 in the opposite direction of the travel hydraulic motor 8, so that the travel hydraulic motor 8 generates travel resistance; Step 3: The whole machine travel mode switching switch 933 is in the climbing gear position, and the vehicle is traveling on a flat road section. The enabling switch 932 is pressed to operate the travel control handle 931 to control the whole machine to move forward or backward. At this time, the brake solenoid valve 7 is energized, and the travel control valve 6 is energized. At this time, the driving force of the whole machine is jointly provided by the travel motor 92 and the travel hydraulic motor 8; When the whole machine starts to move, the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 and the travel hydraulic motor 8 along the direction of wheel movement. When the whole machine starts to stop moving, the travel motor 92 generates a braking torque. When the travel control handle 931 is completely returned to the middle position, the travel control valve 6 and the electromagnet Y3 of the brake solenoid valve 7 lose power, and the oil circuit of the travel hydraulic motor 8 is disconnected, thereby forming a hydrostatic brake. Step 4, when the whole machine travel mode switching switch 933 is in the climbing gear and the vehicle is traveling on a slope, the vehicle posture is detected according to the turntable position stroke detection switch 1022 and the inclination sensor 1021 arranged on the whole machine chassis, and the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 in the opposite direction of the rotation of the travel hydraulic motor 8, so that the travel hydraulic motor 8 generates travel resistance.

[0048] The step 2 is specifically as follows: Step 2.1, detecting whether the whole machine counterweight and the front axle of the vehicle are in the same direction according to the turntable position travel detection switch 1022 arranged on the whole machine chassis; Step 2.2: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of α ( ) starts to go downhill, at this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve 61 loses power, the electromagnet Y2 is energized, and the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 in the opposite direction of the rotation of the travel hydraulic motor 8, and the travel hydraulic motor 8 generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process to prevent slipping; Figure 8 As shown; Step 2.3: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -α ( ) starts to go downhill, at this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve 61 loses power, the electromagnet Y2 is energized, and the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 in the opposite direction of the rotation of the travel hydraulic motor 8, and the travel hydraulic motor 8 generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process to prevent slipping; Fig. 9 As shown; The step 4 is specifically as follows: Step 4.1: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of α ( ) starts to go downhill, at this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve 61 loses power, the electromagnet Y2 is energized, and the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 in the opposite direction of the rotation of the travel hydraulic motor 8, and the travel hydraulic motor 8 generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process and preventing it from slipping; Step 4.2: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of β ( ) starts to go downhill on the slope. When the whole machine starts to move, the brake solenoid valve 7 is energized, the travel control valve 6 is de-energized, and the valve core returns to the middle position, so that the oil in and out of the travel hydraulic motor 8 is in the travel control valve 6, and the oil circuit is connected. The travel hydraulic motor 8 does not provide driving force; Fig.10 As shown; When the whole machine stops moving, the travel motor 92 generates a braking torque. When the travel control handle 931 returns to the center position, the electromagnet Y3 of the brake solenoid valve 7 loses power, and the oil circuit of the travel hydraulic motor 8 is disconnected, thereby forming a hydrostatic brake. Step 4.3: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -α ( ) starts to go downhill, at this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve 61 loses power, the electromagnet Y2 is energized, and the system controller 101 controls the hydraulic pump 3 to supply oil to the travel control valve 6 in the opposite direction of the rotation of the travel hydraulic motor 8, and the travel hydraulic motor 8 generates travel resistance, thereby ensuring the speed of the whole machine is stable during the downhill process to prevent slipping; Fig.11 As shown; Step 4.4: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -β ( ) starts to go downhill on the slope. When the whole machine starts to move, the brake solenoid valve 7 is energized, the travel control valve 6 is de-energized, and the valve core returns to the middle position, so that the oil in and out of the travel hydraulic motor 8 is in the travel control valve 6, and the oil circuit is connected. The hydraulic travel motor does not provide driving force; When the whole machine stops moving, the travel motor 92 generates a braking torque. When the travel control handle 931 returns to the center position completely, the electromagnet Y3 of the brake electromagnet loses power, and the oil circuit of the travel hydraulic motor 8 is disconnected, thereby forming a hydrostatic brake.

[0049] Example 2 The brake solenoid valve 7 includes a valve core displacement sensor, which has an additional control logic. When the valve core displacement sensor detects that the valve core movement meets the judgment logic, the whole machine starts to travel. Otherwise, the system controller 101 displays a fault code and the whole machine is restricted from traveling.

[0050] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0051] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein. The brake solenoid valve 7 includes a valve core displacement sensor, which has an additional control logic. When the valve core displacement sensor detects that the valve core movement meets the judgment logic, the whole machine starts to travel. Otherwise, the system controller 101 displays a fault code and the whole machine is restricted from traveling.

[0052] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0053] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An auxiliary drive and brake control system for a boom-type aerial work platform, characterized in that: It includes a hydraulic oil tank (1), a drive device (2), a hydraulic pump (3), a main control valve (4), a working hydraulic system (5), a travel control valve (6), a brake solenoid valve (7), a travel hydraulic motor (8), a travel drive system (9) and a system controller assembly (10); The main control valve (4) is connected to the travel control valve (6) via a hydraulic pipeline. The driving device (2) drives the hydraulic pump (3) to rotate to take oil from the hydraulic oil tank (1). The hydraulic oil enters the oil inlet P of the main control valve (4) and the oil inlet P of the travel control valve (6) through a hydraulic hose. The LS port of the travel control valve (6) and the LS port of the main control valve (4) are connected via a hydraulic pipeline. The working hydraulic system (5) controls and distributes hydraulic oil through the main control valve (4); The travel hydraulic motor (8) comprises a right motor and a left motor respectively connected to the right tire and the left tire of the front axle assembly of the whole machine; the brake solenoid valve (7) comprises a first brake solenoid valve (71) and a second brake solenoid valve (72) arranged on the oil circuit between the oil ports A and B on both sides of the right motor and the travel control valve (6); and further comprises a third brake solenoid valve (73) and a fourth brake solenoid valve (74) arranged on the oil circuit between the oil ports A and B on both sides of the left motor and the travel control valve (6); The oil ports FRA, FRB, FLA and FLB of the travel control valve (6) are respectively connected to the first brake solenoid valve (71), the second brake solenoid valve (72), the third brake solenoid valve (73) and the fourth brake solenoid valve (74) through hydraulic pipelines; The system controller assembly (10) comprises a system controller (101) and a sensor assembly (102), and the system controller (101) controls the brake solenoid valve (7) and the travel system according to data information measured by the sensor assembly (102).

2. The auxiliary driving and braking control system for a boom-type aerial work platform according to claim 1 is characterized in that: The travel control valve (6) comprises a three-position four-way electromagnetic reversing valve (61) and a flow-dividing and collecting valve (62); the three-position four-way electromagnetic reversing valve (61) is provided with electromagnets Y1 and Y2 controlled by a system controller (101); an oil inlet of the three-position four-way electromagnetic reversing valve (61) is connected to an oil inlet P of a main control valve (4) and an oil outlet of a hydraulic pump (3); the three-position four-way electromagnetic reversing valve (61) has two oil outlets, one of which is connected to two oil ports FRB and FLA of the travel control valve (6), and the other is connected to an oil inlet of the flow-dividing and collecting valve (62); A shuttle valve (63) is provided between the hydraulic pipelines connected to the two oil outlets of the three-position four-way solenoid reversing valve (61); the oil outlet of the shuttle valve (63) is connected to the load-sensitive oil port LS of the travel control valve (6) through the hydraulic pipeline, and a first check valve (64) is provided on the pipeline, the oil inlet of which is connected to the oil outlet of the shuttle valve (63); It also includes a second one-way valve (65), a third one-way valve (66) and a fourth one-way valve (67) whose oil inlet is connected to the oil return port T of the travel control valve (6) through a hydraulic pipeline. The second one-way valve (65) and the third one-way valve (66) are respectively arranged on the hydraulic pipeline between the two oil outlets of the flow dividing and collecting valve (62) and the oil return port T of the travel control valve (6). The fourth one-way valve (67) is arranged on the hydraulic pipeline between the hydraulic pipeline connecting the three-position four-way solenoid reversing valve (61) and the oil ports FRB and FLA and the oil return port T of the travel control valve (6); A throttle valve (68) is provided between the two oil outlets of the flow-dividing and flow-collecting valve (62), the two ends of the throttle valve (68) being in communication with the oil outlet pipeline of the flow-dividing and flow-collecting valve (62).

3. The auxiliary driving and braking control system for a boom-type aerial work platform according to claim 2 is characterized in that: Any of the brake solenoid valves (7) comprises a two-position, two-way, two-way stop valve (75), the two-position, two-way stop valve (75) being provided with an electromagnet Y3 controlled by a system controller (101), and a filter screen (72) being provided between the two-position, two-way, two-way stop valve (75) and an oil inlet of the brake solenoid valve (7).

4. The auxiliary driving and braking control system for a boom-type aerial work platform according to claim 3 is characterized in that: The two-position, two-way, two-way stop valve (75) is provided with a valve core displacement sensor (77), and the valve core displacement sensor (77) is connected to the system controller (101) via a signal harness.

5. The auxiliary driving and braking control system for a boom-type aerial work platform according to claim 4, characterized in that: A first overflow valve (11), a second overflow valve (12), a third overflow valve (13) and a fourth overflow valve (14) are respectively provided on the hydraulic pipelines connecting the first brake solenoid valve (71), the second brake solenoid valve (72), the third brake solenoid valve (73) and the fourth brake solenoid valve (74) with the left motor and the right motor, and the oil return ports of the first overflow valve (11), the second overflow valve (12), the third overflow valve (13) and the fourth overflow valve (14) are connected to the hydraulic oil tank (1).

6. The auxiliary driving and braking control system for a boom-type aerial work platform according to claim 5, characterized in that: The main control valve (4) comprises a multi-valve for providing hydraulic oil distribution for the working hydraulic system (5); and further comprises a load-sensitive valve (41) arranged between an oil inlet pipeline and an oil outlet pipeline of the main control valve (4); the load-sensitive valve (41) is connected to a load-sensitive oil port LS of the main control valve (4); the load-sensitive oil port LS of the main control valve (4) is connected to a load-sensitive oil port of the travel control valve (6) via a hydraulic pipeline; and a fifth overflow valve (42) is further arranged between the oil inlet pipeline and the oil outlet pipeline of the main control valve (4).

7. A boom-type aerial work platform auxiliary drive braking control method, characterized in that: It includes a travel drive system (9) and a sensor assembly (102) mounted on a turntable of the whole machine; The sensor assembly (102) comprises an inclination sensor (1021) and a travel detection switch (1022), and the inclination sensor (1021) and the travel detection switch (1022) are connected to the system controller (101) via a signal harness; The travel drive system (9) comprises two travel motors (92) which are connected to the left tire and the right tire of the rear axle of the whole machine through a travel reducer (91) and a travel control system (93) for controlling the travel motors (92); The travel control system (93) comprises a travel control handle (931), an enabling switch (932) and a travel mode switching switch (933). When the travel mode switching switch (933) is switched to a four-wheel climbing gear driving mode, the enabling switch (932) is triggered and the travel control handle (931) is operated simultaneously. At this time, the system controller (101) controls the drive device (2) to rotate at a set speed, and the oil of the hydraulic pump (3) supplies oil to the travel motor through the travel control valve (6) and the brake solenoid valve (7); The walking mode switching switch (933) includes a flat ground gear position and a climbing gear position; The specific control method includes the following steps: Step 1: The whole machine travel mode switch (933) is in the flat ground gear position, the vehicle is traveling on a flat road section, the enabling switch (932) is pressed to operate the travel control handle (931) to control the whole machine to move forward or backward, the brake solenoid valve (7) is energized, and the oil inlet and outlet of the travel hydraulic motor (8) are connected in the travel control valve (6); When the whole machine starts to stop moving, the travel motor (92) generates a braking torque. When the travel control handle (931) is completely returned to the center position, the electromagnet Y3 on the brake solenoid valve (7) loses power, and the oil circuit of the travel hydraulic motor (8) is disconnected, thereby forming a hydrostatic brake. Step 2: When the whole machine travel mode switching switch (933) is in the flat ground gear position and the vehicle is traveling on a slope, the vehicle posture is detected according to the turntable position travel detection switch (1022) and the tilt sensor (1021) arranged on the whole machine chassis, and the hydraulic pump (3) is controlled by the system controller (101) to supply oil to the travel control valve (6) in the opposite direction of the rotation of the travel hydraulic motor (8), so that the travel hydraulic motor (8) generates travel resistance; Step 3: The whole machine travel mode switch (933) is in the climbing gear position, and the vehicle is traveling on a flat road section. The enabling switch (932) is pressed to operate the travel control handle (931) to control the whole machine to move forward or backward. At this time, the brake solenoid valve (7) is energized, and the travel control valve (6) is energized. At this time, the driving force of the whole machine is jointly provided by the travel motor (92) and the travel hydraulic motor (8); When the whole machine starts to move, the system controller (101) controls the hydraulic pump (3) to supply oil to the travel control valve (6) and the travel hydraulic motor (8) along the direction of wheel movement. When the whole machine starts to stop moving, the travel motor (92) generates a braking torque. When the travel control handle (931) is completely returned to the center position, the travel control valve (6) and the electromagnet Y3 of the brake solenoid valve (7) lose power, and the oil circuit of the travel hydraulic motor (8) is disconnected, thereby forming a hydrostatic brake. Step 4: When the whole machine travel mode switching switch (933) is in the climbing gear and the vehicle is traveling on a slope, the vehicle posture is detected based on the turntable position travel detection switch (1022) and the inclination sensor (1021) arranged on the whole machine chassis, and the system controller (101) controls the hydraulic pump (3) to supply oil to the travel control valve (6) in the opposite direction of the rotation of the travel hydraulic motor (8), so that the travel hydraulic motor (8) generates travel resistance.

8. The auxiliary driving and braking control method of a boom-type aerial work platform according to claim 7, characterized in that: The step 2 is specifically as follows: Step 2.1, detecting whether the whole machine counterweight and the front axle of the vehicle are in the same direction according to the turntable position travel detection switch (1022) arranged on the whole machine chassis; Step 2.2: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of α ( ) starts to go downhill, at which time the electromagnet Y1 of the three-position four-way electromagnetic reversing valve (61) loses power, the electromagnet Y2 is energized, and the system controller (101) controls the hydraulic pump (3) to supply oil to the travel control valve (6) in the opposite direction of the rotation of the travel hydraulic motor (8), so that the travel hydraulic motor (8) generates travel resistance, thereby ensuring that the speed of the whole machine is stable during the downhill process and preventing it from slipping; Step 2.3: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -α ( ) starts to go downhill. At this time, the electromagnet Y1 of the three-position four-way electromagnetic reversing valve (61) loses power, and the electromagnet Y2 is energized. The system controller (101) controls the hydraulic pump (3) to supply oil to the travel control valve (6) in the opposite direction of the rotation of the travel hydraulic motor (8). The travel hydraulic motor (8) generates travel resistance, thereby ensuring that the speed of the entire machine is stable during the downhill process and preventing it from slipping.

9. The auxiliary driving and braking control method of a boom-type aerial work platform according to claim 8, characterized in that: The step 4 is specifically as follows: Step 4.1: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as α ( ) starts to go downhill, at which time the electromagnet Y1 of the three-position four-way electromagnetic reversing valve (61) loses power, the electromagnet Y2 is energized, and the system controller (101) controls the hydraulic pump (3) to supply oil to the travel control valve (6) in the opposite direction of the rotation of the travel hydraulic motor (8), so that the travel hydraulic motor (8) generates travel resistance, thereby ensuring that the speed of the whole machine is stable during the downhill process and preventing it from slipping; Step 4.2: When the machine counterweight and the front axle of the vehicle are in the same direction, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of β ( ) starts to go downhill, when the whole machine starts to move, the brake solenoid valve (7) is energized, the travel control valve (6) is de-energized, and the valve core returns to the middle position, so that the oil inlet and outlet of the travel hydraulic motor (8) are in the travel control valve (6), and the oil circuit is connected, and the travel hydraulic motor (8) does not provide driving force; When the whole machine stops moving, the travel motor (92) generates a braking torque. When the travel control handle (931) is completely returned to the center position, the electromagnet Y3 of the brake solenoid valve (7) loses power, and the oil circuit of the travel hydraulic motor (8) is disconnected, thereby forming a hydrostatic brake. Step 4.3: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -α ( ) starts to go downhill, at which time the electromagnet Y1 of the three-position four-way electromagnetic reversing valve (61) loses power, the electromagnet Y2 is energized, and the system controller (101) controls the hydraulic pump (3) to supply oil to the travel control valve (6) in the opposite direction of the rotation of the travel hydraulic motor (8), so that the travel hydraulic motor (8) generates travel resistance, thereby ensuring that the speed of the whole machine is stable during the downhill process and preventing it from slipping; Step 4.4: When the machine counterweight and the front axle of the vehicle are in different directions, define the inclination angle between the machine and the ground as , if the whole machine is at an inclination angle of -β ( ) starts to go downhill, when the whole machine starts to move, the brake solenoid valve (7) is energized, the travel control valve (6) is de-energized, and the valve core returns to the middle position, so that the oil inlet and outlet of the travel hydraulic motor (8) are in the travel control valve (6), and the oil circuit is connected, and the hydraulic travel motor does not provide driving force; When the whole machine stops moving, the travel motor (92) generates a braking torque. When the travel control handle (931) is completely returned to the center position, the electromagnet Y3 of the brake electromagnet loses power, and the oil circuit of the travel hydraulic motor (8) is disconnected, thereby forming a hydrostatic brake.

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