A modular walking control system and control method for a walking excavator

Abstract

The present invention provides a modular walking control system and control method for a walking excavator. By combining an electro-hydraulic proportional pressure reducing valve and a hydraulically controlled proportional motor, according to the relationship between the displacement and control pressure of the hydraulically controlled proportional motor and the corresponding relationship between the pressure and current of the electro-hydraulic proportional pressure reducing valve, speed regulation is achieved through corresponding control strategies: the displacement of the left and right motors is set through the display interface, the controller calculates the hydraulic control pressure based on the relationship between the motor displacement and the pressure characteristic curve, calculates the control current according to the corresponding relationship between the electro-hydraulic valve pressure and the current characteristic curve, sends out a current signal to achieve the required setting of the motor displacement, and the displacement is switched through the control panel switching button during operation to perform speed switching, making full use of the engine power. In this way, the displacement setting of the motor can be quickly achieved according to needs, the operation is simple, multiple groups of electro-hydraulic proportional pressure reducing valve pressures can be set according to needs, and the displacement setting of each motor can be controlled separately, ensuring good speed consistency; the electro-hydraulic split control method meets the needs of intelligent and remote operation, thereby improving work efficiency.

Description

Technical Field

[0001] The present invention relates to a walking control system and control strategy for a remote-controlled modular walking hydraulic excavator, belonging to the technical field of walking excavators. Background Art

[0002] Natural disasters occur frequently in China. As an important part of rescue and relief equipment, excavators play an important role in rescue and relief. The ET walking excavator developed by XCMG has characteristics such as high mobility, flexibility, and multi-function, and has strong function expansion ability. Due to the harsh working environment of rescue and relief equipment, it is required to develop a modular walking hydraulic excavator based on this equipment, which can be quickly disassembled, assembled, and transported lightly, and is used for earthquake, geological disaster, and forest fire fighting and rescue, and has a remote control operation function to quickly open up the life channel.

[0003] However, the walking pump of the ET walking excavator is hydraulically controlled, and mainly has the following disadvantages:

[0004] One pump controls multiple motors. The motors are hydraulically controlled two-point variables. The diameters of the front and rear wheels are different. The motor displacement is adjusted on-site after leaving the production line, and the operation is complex; the displacement switching of multiple motors is controlled by one-way oil, and it is difficult to ensure speed consistency; the speed cannot be simply and quickly adjusted in multiple gears, and the engine power cannot be fully utilized; the existing rotary body structure only has a hydraulic channel and no brush structure, and the motor cannot be electrically controlled, which cannot meet the needs of intelligent and remote operation. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a walking control system and control method for a modular walking hydraulic excavator, which can improve work efficiency and meet the needs of intelligent and remote operation.

[0006] To achieve the above purpose, the present invention is implemented by the following technical solutions:

[0007] In the first aspect, the present invention provides a walking control system for a modular walking hydraulic excavator, including:

[0008] An oil tank for loading oil and providing an oil source for the system;

[0009] An engine for providing power for the working pump;

[0010] A working pump is connected to the engine through a coupling. The suction port S of the working pump is communicated with the oil tank. The oil outlet of the working pump leads a path of oil to provide an oil source for the control valve group and a path for providing an oil source for the working device.

[0011] The working oil ports of the walking pump are in parallel with the oil ports of the left walking motor and the right walking motor, and are used to drive the left and right walking motors to rotate;

[0012] A control valve group is used to reduce the pressure of the pressure oil from the working pump and proportionally control the displacement of the travel motor, thereby controlling the travel speed.

[0013] A pressure measuring joint is installed at the outlet of the proportional pressure reducing valve of the control valve group and is used to detect the change in the pressure of the motor hydraulic control port.

[0014] A slewing body is used to connect the upper and lower vehicle oil circuits and is the connection channel for the upper and lower vehicle oil circuits of the machine.

[0015] The left travel motor and the right travel motor are used to control the forward and backward movement of the machine.

[0016] A display is connected to the controller and is used for setting the main machine parameters.

[0017] A controller is connected to the control valve group and is used for collecting signals and output control of the control signals.

[0018] A three-way joint is used to split the pressure oil at the outlet of the working pump into two paths; one path provides an oil source for the control valve group, and the other path is used to provide an oil source for the working device.

[0019] Further, the control valve group is integrated by three pressure reducing valves, including a pressure reducing overflow valve, a proportional pressure reducing overflow valve II, and a proportional pressure reducing overflow valve III.

[0020] The pressure reducing overflow valve is used for the first-stage pressure reduction of the high-pressure oil at the outlet of the working pump and provides a pilot oil source for the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III.

[0021] The proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III are used to proportionally regulate the pressure of the hydraulic control ports of the left and right travel motors.

[0022] Further, the control valve group further includes a valve block.

[0023] The valve block is the carrier of the pressure reducing overflow valve, the proportional pressure reducing overflow valve II, and the proportional pressure reducing overflow valve III, and is used to integrally assemble the corresponding cartridge valves, internally process the corresponding oil channels, connect the corresponding oil ports of the pressure reducing overflow valve, the proportional pressure reducing overflow valve II, and the proportional pressure reducing overflow valve III, arrange the corresponding oil ports according to the requirements of the pipeline connection layout, and connect with other components for control.

[0024] Further, the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III are of the direct-acting cartridge type, and the pressure-reducing output pressure is proportionally regulated according to the DC output current.

[0025] Further, a branch of the oil from the working pump is connected to the inlet P of the control valve group, the inlet P is connected to the P1 port of the pressure reducing overflow valve, and the outlet A1 of the pressure reducing overflow valve is connected to the inlets P2 and P3 of the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III.

[0026] The outlets A2 and A3 of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III are connected through the oil ports TR1 and TR2 of the control valve group and the oil ports of the slewing body. The T1 port of the pressure reducing and overflow valve and the T2 and T3 ports of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III are connected through the internal channels of the valve block and return to the oil tank through the T port.

[0027] The outlets A2 and A3 of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III are in parallel with two internal oil channels of the valve block. The M1 and M2 oil ports are connected to the pressure measuring joints to detect the outlet pressure after pressure reduction of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III for troubleshooting.

[0028] The outlets 2 and 4 of the slewing body are connected to the servo mechanism oil ports X1 and X2 of the motor.

[0029] The working pump is connected to the engine through a coupling, and the S and T ports of the working pump are connected to the oil tank.

[0030] The A port of the travel pump is connected to the B2 and A1 ports of the left and right travel motors, and the B port is connected to the A2 and B1 ports of the left and right travel motors.

[0031] The DT1 and DT2 ports of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III are connected to the ports of the controller.

[0032] Furthermore, the display is connected to the controller through CAN to obtain the displacements V 1i 、V 2i of the left and right travel motors.

[0033] The controller calculates the hydraulic control pressures P 1i 、P 2i of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III according to the relationship between the displacements and pressure characteristic curves of the left and right travel motors.

[0034] According to the corresponding relationship between the valve pressure and current characteristic curves of the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III, the control currents I 1i 、I 2i required by the electro-hydraulic proportional pressure reducing valve are calculated.

[0035] The controller outputs the current signals I 1i 、I 2i to control the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III. The proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III perform proportional adjustment according to the DC output current and output precise pressure oil P 1i 、P 2i The pressure oil passes through the center slewing body and reaches the servo mechanisms of the left and right travel motors to control the swashplate angles of the left and right motors, realizing the displacement setting V 1i 、V 2i of the motors.

[0036] Further, the walking pump is hydraulically controlled by an electric control, and the displacement of the pump is controlled by proportional solenoid valves DT3 and DT4.

[0037] Further, the control method of the walking motor is hydraulic proportional control. The displacement of the motor is adjusted by proportional reducing overflow valve II and proportional reducing overflow valve III in the control valve group. After two-stage decompression, the servo mechanisms of the left and right walking motors are controlled to adjust the displacement of the left and right walking motors, so as to control the adjustment of the walking speed.

[0038] In a second aspect, the present invention provides a modular walking hydraulic excavator walking control method. Based on the system described in the first aspect, it includes the following steps:

[0039] Set the displacements V 1i 、V 2i of the left and right walking motors through the display interface;

[0040] The controller calculates the hydraulic control pressures P 1i 、P 2i of proportional reducing overflow valve II and proportional reducing overflow valve III according to the relationship between the displacements and pressure characteristic curves of the left and right walking motors;

[0041] According to the corresponding relationship between the valve pressure and current characteristic curves of proportional reducing overflow valve II and proportional reducing overflow valve III, calculate the current I 1i 、I 2i that the electro-hydraulic proportional relief valve needs to control;

[0042] The controller outputs current signals I 1i 、I 2i to control proportional reducing overflow valve II and proportional reducing overflow valve III. Proportional reducing overflow valve II and proportional reducing overflow valve III perform proportional adjustment according to the DC output current and output precise pressure oil P 1i 、P 2i . The pressure oil passes through the central slewing body and reaches the left and right walking motor servo mechanisms to control the swash plate angles of the left and right motors, realizing the displacement setting V 1i 、V 2i of the motors.

[0043] Further, the method further includes:

[0044] Set different values for the displacements V 1i 、V 2i of the motor according to the speed requirement to perform multi-gear adjustment of the speed.

[0045] Further, the method further includes:

[0046] During operation, for high and low speed switching, two-point displacement switching is achieved through the switching button on the control panel to perform speed switching.

[0047] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0048] The present invention provides an electro-hydraulic split-type walking control method. By combining an electro-proportional pressure reducing valve and a hydraulically controlled proportional motor, according to the relationship between the displacement and control pressure of the hydraulically controlled proportional motor and the corresponding relationship between the pressure and current of the electro-proportional pressure reducing valve, the adjustment of the motor displacement is quickly achieved through corresponding control strategies, realizing multi-gear adjustment of the walking speed. The motor displacement is separately controlled by the electro-proportional pressure reducing valve to ensure speed consistency; after improvement, the operation complexity is reduced, intelligent and remote operation control are satisfied, the work efficiency is improved, and energy consumption is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the composition of the principle diagram of the walking speed control system;

[0050] Figure 2 It is a schematic diagram of the principle block diagram of the walking speed control strategy.

[0051] In the figure: 1, fuel tank; 2, engine; 3, working pump; 4, walking pump; 5, control valve group; 6, pressure measuring joints (M1, M2); 7, slewing body; 8, left walking motor; 9, right walking motor; 10, display; 11, controller; 12, three-way joint;

[0052] 5, control valve group; 5.1, pressure reducing and overflow valve; 5.2, proportional pressure reducing and overflow valve II; 5.3, proportional pressure reducing and overflow valve III; 5.4, valve block. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0054] Embodiment 1:

[0055] This embodiment provides a modular walking control system for a tracked hydraulic excavator, including:

[0056] Fuel tank 1, used to load oil and provide an oil source for the system;

[0057] Engine 2, used to provide power for the working pump;

[0058] Working pump 3, connected to the engine through an elastic coupling. The suction port S of the working pump is connected to the fuel tank, and the oil outlet of the working pump leads a path of oil to the control valve group 5 through the three-way joint 12 and another path is used to provide an oil source for the working device.

[0059] Walking pump 4, with its working oil port in parallel with the oil ports of the left and right walking motors, used to drive the left and right walking motors to rotate.

[0060] A control valve group 5 for reducing the pressure of the pressure oil from the working pump and proportionally controlling the displacement of the travel motor, thereby controlling the travel speed;

[0061] Pressure measurement connectors 6 (M1, M2), installed at the outlet of the proportional pressure reducing valve of the control valve group, for detecting the pressure change at the hydraulic control port of the motor;

[0062] A slewing body 7 for connecting the upper and lower vehicle oil circuits, which is the connection channel for the upper and lower vehicle oil circuits;

[0063] A left travel motor 8 and a right travel motor 9 for controlling the forward and backward movement of the machine;

[0064] A display 10, connected to the controller, for setting the parameters of the main machine

[0065] A controller 11, connected to the control valve group, for collecting signals and output control of the control signals;

[0066] A three-way joint 12 for splitting the pressure oil at the outlet of the working pump into two paths; one path supplies the oil source for the control valve group 5, and the other path supplies the oil source for the working device,

[0067] Specifically, the control valve group 5 includes a pressure reducing overflow valve 5.1, proportional pressure reducing overflow valves 5.2, 5.3, and a valve block 5.4. The valve block is the carrier of the pressure reducing overflow valve 5.1 and the proportional pressure reducing overflow valves 5.2, 5.3, used for integrating and assembling the corresponding cartridge valves, machining the corresponding oil channels inside, connecting the corresponding oil ports of 5.1 / 5.2 / 5.3, arranging the corresponding oil ports according to the requirements of the pipeline connection layout, and connecting with other components for control.

[0068] Specifically, the control valve group 5 is integrated by three pressure reducing valves,

[0069] The pressure reducing overflow valve 5.1 is used for the first-stage pressure reduction of the high-pressure oil at the outlet of the working pump, providing the pilot oil source for the proportional pressure reducing overflow valves 5.2, 5.3. It is a high-pressure, large-flow direct-acting, cartridge type, with fast response to dynamic pressure changes, small hysteresis, precise pressure control, and low pressure drop;

[0070] The electro-hydraulic proportional pressure reducing overflow valves 5.2 / 5.3 are used for proportionally adjusting the pressure at the hydraulic control ports of the left and right travel motors. They are direct-acting, cartridge type. The reduced output pressure is proportionally adjusted according to the DC output current, with precise pressure and current control characteristics and excellent repeatability, and fast response to dynamic pressure changes;

[0071] Specifically, a branch of the oil from the working pump is connected to the inlet P of the control valve group 5, P is connected to the P1 port of the pressure reducing overflow valve 5.1, and the outlet A1 of the pressure reducing overflow valve 5.1 is connected to the inlets P2, P3 of the proportional pressure reducing overflow valves 5.2, 5.3;

[0072] The outlets A2 and A3 of the proportional pressure-reducing overflow valves 5.2 and 5.3 are connected to the oil ports 1 and 3 of the rotary body 7 through the oil ports TR1 and TR2 of the control valve group 5. The T1 port of the pressure-reducing overflow valve 5.1 and the T2 and T3 ports of the proportional pressure-reducing overflow valves 5.2 and 5.3 are connected through the internal channels of the valve block 5.4 and return to the oil tank 1 through the T port.

[0073] The outlets A2 and A3 of the proportional pressure-reducing overflow valves 5.2 and 5.3 are in parallel with two internal oil channels of the valve block. The M1 and M2 oil ports are connected with pressure measuring joints 6 to detect the outlet pressure after pressure reduction of 5.2 and 5.3 for troubleshooting.

[0074] Specifically, the traveling speed control system of this embodiment, as Figure 1 shown, includes: an oil tank 1; an engine 2; a working pump 3; a traveling pump 4; a control valve group 5; pressure measuring joints 6 (M1, M2); a rotary body 7; a left traveling motor 8; a right traveling motor; a display; a controller; a tee joint; the control valve group 5 includes a pressure-reducing overflow valve 5.1, proportional pressure-reducing overflow valves 5.2 and 5.3, and a valve block 5.4. The working pump 3 and the traveling pump 4 are connected in series and connected to the engine 2 through a coupling. The working pump 3 provides an oil source for the working device, and a path of oil is led through the tee joint 12 to provide an oil source for the control valve group 5; the traveling pump 4 is changed from hydraulic control to electric control, and the displacement of the pump is controlled by proportional solenoid valves DT3 and DT4. The traveling motors 8 and 9 are changed from hydraulic control at two points to hydraulic control in proportion, and the displacement of the motors is adjusted by the proportional pressure-reducing overflow valves 5.2 and 5.3 in the control valve group 5. After two-stage pressure reduction, the servo mechanisms of the left and right traveling motors 8 and 9 are controlled to further control the displacement adjustment of the left and right traveling motors to control the adjustment of the traveling speed; the control valve group 5 is integrated by three pressure-reducing valves. The pressure-reducing overflow valve 5.1 is a high-pressure, large-flow direct-acting and cartridge type, which has a fast response ability to dynamic pressure changes, a small hysteresis loop, precise pressure control, and a low pressure drop; the electro-proportional pressure-reducing overflow valves 5.2 / 5.3 are direct-acting and cartridge type, and the pressure-reducing output pressure is adjusted proportionally according to the DC output current, with precise pressure and current control characteristics and excellent repeatability, and has a fast response ability to dynamic pressure changes; the pressure measuring joint 6 is used to detect the pressure change at the hydraulic control port of the motor.

[0075] The central rotary body 7 is the connection channel for the upper and lower vehicle oil circuits; the controller is used for collecting signals and output control of signals; the display is connected to the controller through CAN for setting the host parameters.

[0076] The working pump diverts a branch of oil to connect with the oil inlet P of the control valve group 5. P is connected to the P1 port of the pressure reducing and overflow valve 5.1. The outlet A1 of the pressure reducing and overflow valve 5.1 is connected to the inlets P2 and P3 of the proportional pressure reducing and overflow valves 5.2 and 5.3. The outlets A2 and A3 of the proportional pressure reducing and overflow valves 5.2 and 5.3 are connected to the oil ports 1 and 3 of the slewing body 7 through the control valve groups TR1 and TR2. The T1 port of the pressure reducing and overflow valve 5.1, and the T2 and T3 ports of the proportional pressure reducing and overflow valves 5.2 and 5.3 are connected through the internal channels in the valve block 5.4 and return to the oil tank 1 through the T port. The outlets A2 and A3 of the proportional pressure reducing and overflow valves 5.2 and 5.3 are connected in parallel with two branches of oil M1 and M2 and the pressure measuring joint 6. The outlets 2 and 4 of the slewing body 7 are connected to the servo mechanism oil ports X1 and X2 of the motors 9 and 8. The working pump 3 is connected to the engine 2 through a coupling, and the S and T ports are connected to the oil tank 1. The A port of the traveling pump is connected to the left and right traveling motors 8 and 9, the B2 port and the A1 port, and the B port is connected to the A2 port and the B1 port of the left and right traveling motors 8 and 9. The DT1 and DT2 of the proportional pressure reducing and overflow valves 5.2 and 5.3 are connected to the ports of the controller, and the display is connected to the controller through CAN.

[0077] The traveling speed control strategy is as follows:

[0078] Set the displacements V 1i 、V 2i of the left and right traveling motors 8 and 9 through the display interface. The controller calculates the hydraulic control pressures P 1i 、P 2i of the electro-hydraulic proportional pressure reducing valves 5.2 and 5.3 based on the relationship between the displacements and pressure characteristics curves of the left and right traveling motors. Further, according to the corresponding relationship between the valve pressure and current characteristics curves of the electro-hydraulic proportional pressure reducing valves 5.2 and 5.3, calculate the control currents I 1i 、I 2i required for the electro-hydraulic proportional pressure reducing valves. The controller outputs the current signals I 1i 、I 2i to control the electro-hydraulic proportional pressure reducing valves 5.2 and 5.3. The electro-hydraulic proportional pressure reducing valves 5.2 and 5.3 perform proportional regulation according to the DC output current and output precise pressure oil P 1i 、P 2i . The pressure oil passes through the central slewing body 7 and reaches the servo mechanisms of the left and right traveling motors to control the swash plate angles of the left and right motors, realizing the displacement setting V 1i 、V 2i of the motors. The displacements V 1i 、V 2i of the motors can be set to different values according to the speed requirements for multi-speed regulation. During operation, for high and low speed switching, two-point displacement switching is achieved through the switching button on the control panel for speed switching.

[0079] The present invention provides an electro-hydraulic split control method. By combining an electro-proportional pressure reducing valve and a hydraulically controlled proportional motor, according to the relationship between the displacement and control pressure of the hydraulically controlled proportional motor and the corresponding relationship between the pressure and current of the electro-proportional pressure reducing valve, speed regulation is achieved through corresponding control strategies: the left and right motor displacements are set through the display interface, and the controller calculates the hydraulically controlled pressure based on the relationship between the motor displacement and the pressure characteristic curve. According to the corresponding relationship between the pressure and current characteristic curves of the electro-proportional valve, the control current is calculated, and a current signal is sent to achieve the required setting of the motor displacement. During operation, the displacement is switched through the control panel switching button to perform speed switching, making full use of the engine power. In this way, the displacement setting of the motor can be quickly achieved as needed, the operation is simple, multiple groups of electro-proportional pressure reducing valve pressures can be set as needed to independently control the displacement setting of each motor, and good speed consistency is ensured; the electro-hydraulic split control method meets the needs of intelligent and remote operation, thereby improving work efficiency.

[0080] Embodiment 2:

[0081] This embodiment provides a modular walking control method for a hydraulic excavator. Based on the system described in Embodiment 1, it includes the following steps:

[0082] Set the displacements V of the left and right travel motors 8 and 9 through the display interface 1i 、V 2i 、The controller calculates the hydraulically controlled pressures P of the electro-proportional pressure reducing valves 5.2 and 5.3 based on the relationship between the displacements of the left and right travel motors and the pressure characteristic curve 1i 、P 2i ,Further, according to the corresponding relationship between the valve pressures and current characteristic curves of the electro-proportional pressure reducing valves 5.2 and 5.3, calculate the control currents I that the electro-proportional pressure reducing valves need 1i 、I 2i ,The controller outputs current signals I 1i 、I 2i To control the electro-proportional pressure reducing valves 5.2 and 5.3, and the electro-proportional pressure reducing valves 5.2 and 5.3 perform proportional regulation according to the DC output current and output precise pressure oil P 1i 、P 2i ,The pressure oil passes through the central slewing body 7 and reaches the servo mechanisms of the left and right travel motors to control the swashplate angles of the left and right motors, achieving the displacement setting V of the motors 1i 、V 2i ,The displacements V of the motors 1i 、V 2i Can be set to different values according to the speed requirements for multi-stage speed regulation. During operation, for high and low speed switching, two-point displacement switching is achieved through the control panel switching button to perform speed switching.

[0083] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0084] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0085] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, so that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable devices provide steps for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0087] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A modular walking type hydraulic excavator travel control system, characterized in that, it includes: An oil tank for loading oil fluid to provide an oil source for the system; An engine for providing power to the working pump; A working pump connected to the engine through a coupling. The suction port S of the working pump is connected to the oil tank, and the outlet of the working pump leads a path of oil through a tee joint to provide an oil source for the control valve group and another path for providing an oil source for the working device, A travel pump whose working oil port is in parallel with the oil ports of the left travel motor and the right travel motor, and is used to drive the left and right travel motors to rotate; A control valve group for reducing the pressure of the pressure oil of the working pump and proportionally controlling the displacement of the travel motor, thereby controlling the travel speed; A pressure measuring joint installed at the outlet of the proportional pressure reducing overflow valve of the control valve group for detecting the pressure change of the motor hydraulic control port; A slewing body for connecting the upper and lower vehicle oil circuits and being the connection channel for the upper and lower vehicle oil circuits of the machine; A left travel motor and a right travel motor for controlling the machine to move forward and backward; A display connected to the controller for setting the main engine parameters; A controller connected to the control valve group for collecting signals and output control of the control signals; A tee joint for splitting the pressure oil at the outlet of the working pump into two paths: one path provides an oil source for the control valve group, and the other path is used to provide an oil source for the working device; The control valve group is integrated by three pressure reducing valves, including a pressure reducing overflow valve, a proportional pressure reducing overflow valve II, and a proportional pressure reducing overflow valve III; The pressure reducing overflow valve is used for the first-stage pressure reduction of the high-pressure oil at the outlet of the working pump to provide a pilot oil source for the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III; The proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III are used for proportionally adjusting the pressure of the hydraulic control ports of the left and right travel motors.

2. The modular walking type hydraulic excavator travel control system according to claim 1, characterized in that, the control valve group further includes a valve block; The valve block is the carrier of the pressure reducing overflow valve, the proportional pressure reducing overflow valve II, and the proportional pressure reducing overflow valve III, and is used for integrally assembling the corresponding cartridge valves, machining the corresponding oil channels inside, connecting the corresponding oil ports of the pressure reducing overflow valve, the proportional pressure reducing overflow valve II, and the proportional pressure reducing overflow valve III, arranging the corresponding oil ports according to the requirements of the pipeline connection layout, and connecting with other components for control.

3. The modular walking type hydraulic excavator travel control system according to claim 1, characterized in that, the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III are of the direct-acting cartridge type, and the pressure-reducing output pressure is proportionally adjusted according to the DC output current.

4. The modular walking type hydraulic excavator travel control system according to claim 2, characterized in that, A path of oil separated from the working pump is connected to the inlet P of the control valve group, the inlet P is connected to the P1 port of the pressure reducing overflow valve, and the outlet A1 of the pressure reducing overflow valve is connected to the inlets P2 and P3 of the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III; The outlets A2 and A3 of the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III are connected to the oil ports of the slewing body through the oil ports TR1 and TR2 of the control valve group. The T1 port of the pressure reducing overflow valve and the T2 and T3 ports of the proportional pressure reducing overflow valve II and the proportional pressure reducing overflow valve III are communicated in the internal channel of the valve block and return to the oil tank through the T port. The outlets A2 and A3 of proportional pressure reducing and overflow valve two and proportional pressure reducing and overflow valve three are in parallel with two oil passages inside the valve block. The oil ports M1 and M2 are connected to pressure measuring joints, which are used to detect the outlet pressure after pressure reduction of proportional pressure reducing and overflow valve two and proportional pressure reducing and overflow valve three for troubleshooting. The outlets 2 and 4 of the rotating body are connected to the servo mechanism oil ports X1 and X2 of the motor. The working pump is connected to the engine through a coupling, and the S and T ports of the working pump are connected to the fuel tank. The A port of the travel pump is connected to the B2 and A1 ports of the left and right travel motors, and the B port of the travel pump is connected to the A2 and B1 ports of the left and right travel motors. The control ports DT1 and DT2 of proportional pressure reducing and overflow valve two and proportional pressure reducing and overflow valve three are connected to the ports of the controller.

5. The modular walking type hydraulic excavator walking control system according to claim 4, characterized in that The display is connected to the controller via CAN to obtain the displacement V of the left and right traveling motors 1i , V 2i ; The controller calculates the hydraulic control pressures P of proportional pressure reducing and overflow valve 2 and proportional pressure reducing and overflow valve 3 based on the relationship between the displacement and pressure characteristic curves of the left and right travel motors. 1i and P 2i , According to the corresponding relationship between the valve pressure and current characteristic curves of proportional pressure reducing overflow valve two and proportional pressure reducing overflow valve three, calculate the current I that the electro-hydraulic proportional pressure reducing valve needs to control 1i 、I 2i , The controller outputs current signals I 1i and I 2i to control Proportional Pressure Reducing and Overflow Valve II and Proportional Pressure Reducing and Overflow Valve III. Proportional Pressure Reducing and Overflow Valve II and Proportional Pressure Reducing and Overflow Valve III are proportionally adjusted according to the DC output current and output precise pressure oil P 1i and P 2i . The pressure oil passes through the central slewing body and reaches the left and right travel motor servo mechanisms to control the swash plate swing angles of the left and right motors, thereby achieving the displacement setting V 1i and V 2i .

6. The modular walking type hydraulic excavator walking control system according to claim 1, characterized in that The travel pump is hydraulically controlled by an electric control, and the displacement of the pump is controlled by proportional solenoid valves DT3 and DT4.

7. The modular walking type hydraulic excavator walking control system according to claim 1, characterized in that The control method of the travel motor is hydraulic control proportional. The displacement of the motor is adjusted by proportional pressure reducing and overflow valve two and proportional pressure reducing and overflow valve three in the control valve group to control the servo mechanisms of the left and right travel motors and the displacement adjustment of the left and right travel motors, so as to control the adjustment of the walking speed.

8. A modular walking type hydraulic excavator walking control method, characterized in that Based on the system according to any one of claims 1-7, it includes the following steps: Set the displacement V of the left and right traveling motors through the display interface 1i , V 2i ; The controller calculates the hydraulic control pressures P 1i and P 2i of proportional pressure reducing and overflow valve II and proportional pressure reducing and overflow valve III based on the relationship between the displacement and pressure characteristic curves of the left and right travel motors. 1i 、P 2i ; According to the corresponding relationship between the valve pressure and current characteristic curves of proportional pressure reducing overflow valve two and proportional pressure reducing overflow valve three, calculate the current I that the electro-hydraulic proportional pressure reducing valve needs to control 1i 、I 2i ; The controller outputs current signals I 1i 、I 2i to control the proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III. The proportional pressure reducing and overflow valve II and the proportional pressure reducing and overflow valve III are proportionally adjusted according to the DC output current and output precise pressure oil P 1i 、P 2i . The pressure oil passes through the central slewing body and reaches the left and right travel motor servo mechanisms to control the swashplate swing angles of the left and right motors, realizing the displacement setting V 1i 、V 2i .

9. The modular walking type hydraulic excavator walking control method according to claim 8, characterized in that The method further includes: Displacement V of the motor 1i 、V 2i Set different values according to the speed requirement for multi - gear speed adjustment; During operation, for high and low speed switching, two-point displacement switching is realized through the switching button on the control panel for speed switching.

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