A hydraulic control system for trenching machine

Abstract

The present invention provides a trencher hydraulic control system, which belongs to a mechanical hydraulic engineering device. The system comprises a hydraulic oil tank, a walking unit, a trenching unit, an excavating unit, a trenching adjustment unit and a heat dissipation unit. The system relates to a complete hydraulic control and driving scheme in the trencher. Under the control of the scheme, the functions of independent control of crawlers on both sides of the trencher, independent operation of a trenching device and an excavating device, flexible adjustment of the overall body angle and trenching depth adjustment can be realized. On the one hand, the passability of the trencher can be greatly improved, and on the other hand, the adaptability of the trencher to uneven roads can be greatly improved, thereby improving the trenching efficiency and ensuring the trenching quality.

Description

Technical Field

[0001] The invention belongs to mechanical hydraulic engineering devices, and in particular relates to a hydraulic control system for a trencher. Background Art

[0002] With the rapid development of my country's transportation industry, trenchers have been widely used in various engineering construction fields such as high-speed railways, subways and highways. In particular, the demand for trench excavation and similar construction in railway pipeline laying projects is increasing. For many years, the mainstream trenchers in the domestic market have been realized through mechanical transmission, mainly used in the agricultural machinery industry, urban and rural optical cables, etc., with a single working condition and many restrictions on the construction site environment. The current mainstream trenchers are designed for different geological conditions. The walking speed of the trencher cannot be accelerated or decelerated according to the construction conditions, the chain saw speed cannot be adjusted, the chain saw cutting torque cannot be adjusted, the trenching depth is difficult to adjust, and the trench opened on the slope surface cannot be guaranteed to be perpendicular to the horizontal plane. The construction environment of the trencher cannot be repaired, resulting in low quality of trench excavation and difficulty in improving construction efficiency. Summary of the invention

[0003] In view of the above-mentioned defects, the present invention relates to a complete hydraulic control and drive scheme in a trencher. Under the control of this scheme, it is possible to realize functions such as independent control of the tracks on both sides of the trencher, independent operation of the trenching device and the excavating device, flexible adjustment of the overall body angle, and trenching depth adjustment. On the one hand, it can greatly improve the passability of the trencher, and on the other hand, it can greatly improve the adaptability of the trencher to uneven roads, thereby improving the trenching efficiency and ensuring the trenching quality.

[0004] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0005] A trenching machine hydraulic control system, characterized in that it includes a hydraulic oil tank, a travel unit, a trenching unit, an excavation unit, a trenching adjustment unit and a heat dissipation unit, wherein: the travel unit is used to independently drive the walking tracks installed on both sides of the chassis, the travel unit includes two sets of motors and their switching valve groups and an oil pump and its control valve group, the travel motor in the motor and its switching valve group is used to drive the movement of the walking tracks, and the travel pump in the oil pump and its control valve group is used to drive the travel motor to work; the trenching unit is used to drive the trenching device to rotate, and the trenching device is rotatably installed on one side of the frame through a rotating shaft, the trenching motor in the trenching unit provides torque to the trenching device through a trenching reducer to drive the trenching rack to move, and the trenching motor is driven by the trenching pump; the excavation unit is used to control the operation of the excavation device, and the excavation device is installed on the other side of the frame; the trenching adjustment unit The unit is used to adjust the angle between the chassis and the frame on the one hand, and to adjust the trenching depth of the trenching device on the other hand. The trenching adjustment unit includes a fixed depth cylinder group and a leveling cylinder group. The fixed depth cylinder group consists of two cylinders with the same working state, one end of the fixed depth cylinder group is hinged on the frame, and the other end of the fixed depth cylinder group is hinged at the tail end of the trenching device. The telescopic movement of the fixed depth cylinder group can drive the trenching device to rotate around the rotating shaft to adjust the depth of the trenching rack into the soil. The leveling cylinder group consists of two cylinders with opposite working states, which are installed between the chassis and the frame. The bottom of the leveling cylinder group is hinged on the crossbeam of the chassis, and the top of the leveling cylinder group is hinged on the crossbeam of the frame. The telescopic movement of the leveling cylinder group can drive the frame to rotate around the hinge axis of the chassis to change the horizontal angle of the frame. The heat dissipation unit is used for heat dissipation of valves, oil pumps and cylinders in the hydraulic control system.

[0006] Preferably, the motor and its switching valve group in the walking unit also include a walking variable oil cylinder, a motor control valve, a first shuttle valve group, a first high-pressure relief valve and a walking reducer, wherein: the input port of the walking variable oil cylinder is connected to the output port of the motor control valve, the motor control valve is a two-position three-way valve, and the walking variable oil cylinder can be adjusted by changing the position of the motor control valve to drive the walking motor to reduce the displacement and increase the speed of the walking motor. The input port of the motor control valve is connected to the output port of the first shuttle valve group, and the input port of the shuttle valve group is connected to the high-pressure oil circuit. The first high-pressure relief valve is used to ensure that the walking motor is within the allowable use range. Inside, the travel reducer is connected to the travel motor for reducing speed and increasing torque; the oil pump and its control valve group in the travel unit also include an oil pump reversing valve, a second high-pressure relief valve, a first oil replenishing relief valve, a first control oil relief valve and a second shuttle valve group, wherein: the oil pump reversing valve is used to control the vehicle to move forward or backward, the executive cylinder of the oil pump reversing valve is connected to the travel pump, the second high-pressure relief valve is installed on the output oil circuit of the travel pump for oil circuit overload unloading, the first oil replenishing relief valve is used to compensate for system leakage and replenish oil to the low-pressure chamber of the closed system, and the first control oil relief valve and the second shuttle valve group are used to supply oil to the variable cylinder of the travel pump.

[0007] Preferably, the trenching unit also includes a trenching reversing valve, a third high-pressure relief valve, a second oil replenishment relief valve, a second control oil relief valve and a third shuttle valve group, wherein: the trenching reversing valve is used to control the forward or reverse rotation of the trenching motor, the third high-pressure relief valve is installed on the output oil circuit of the trenching motor for oil circuit overload unloading, and the second control oil relief valve and the third shuttle valve group are used to supply oil to the variable cylinder of the trenching pump.

[0008] Preferably, the excavation unit includes a load variable pump and a flow control valve. The load variable pump adjusts the output pressure according to the load condition to achieve energy saving. The flow control valve can provide real-time feedback of the load condition to the load variable pump on the one hand, and receive the output pressure oil of the load variable pump to control the operation of the actuator on the other hand, wherein: the load variable pump includes an excavation pump, an excavation variable cylinder, a power control valve, a maximum pressure control valve and a pressure difference control valve. The excavation variable cylinder is used to adjust the output power of the excavation pump. The power control valve is used to control the telescopic stroke of the excavation variable cylinder. The maximum pressure The control valve and the pressure difference control valve receive feedback from the load feedback valve in the flow control valve to control the operation of the power control valve; the flow control valve includes a load feedback valve, a load feedback relief valve, a differential pressure valve, and multiple pressure compensation valves, multiple excavation reversing valves and multiple fourth high-pressure relief valves, wherein: the load feedback valve feeds back the load condition to the load variable pump, the load feedback relief valve is installed at the output port of the load feedback valve, the differential pressure valve is installed on the pressure oil circuit, the pressure compensation valve is used to replenish oil to the working port, and the excavation reversing valve is a three-position six-way valve, which is used to change the direction of the oil circuit in the actuator.

[0009] Preferably, the excavation unit also includes a left feed motor, a right feed motor, a feed switching motor, a groove cylinder, a boom cylinder, a bucket cylinder, an arm cylinder and a breaker hammer, wherein: the left feed motor, the right feed motor, the feed switching motor, the groove cylinder, the boom cylinder, the bucket cylinder, the arm cylinder and the breaker hammer are respectively connected to the output port of the excavation reversing valve.

[0010] Preferably, the ditching adjustment unit also includes an adjusting oil pump, a superimposed valve, a pressure control valve, a depth-setting directional control valve, a leveling directional control valve, a depth-setting oil replenishment valve and a leveling oil replenishment valve, wherein: the superimposed valve is composed of a superimposed valve block, a superimposed overflow valve and a high-frequency proportional reversing valve, and is used to drive the depth-setting directional control valve and the leveling directional control valve to change direction, the pressure control valve is used for overload unloading, the depth-setting directional control valve and the leveling directional control valve are both two-position four-way valves used to change the oil circuit direction of the connected cylinders, the depth-setting oil replenishment valve is arranged between the depth-setting directional control valve and the depth-setting cylinder group for oil supply, the leveling oil replenishment valve is arranged between the leveling cylinder group and the leveling directional control valve for oil supply, and an overflow valve is also connected in parallel in the oil circuits of the depth-setting oil replenishment valve and the leveling oil replenishment valve.

[0011] Preferably, the heat dissipation unit includes a heat dissipation pump, a heat dissipation control valve, a heat dissipation motor and a radiator. The heat dissipation pump provides power to the heat dissipation motor through the heat dissipation control valve. The heat dissipation control valve is used to control whether the heat dissipation motor is working. Heat dissipation blades are provided on the rotating shaft of the heat dissipation motor. The radiator is close to the heat dissipation blades. The oil circuit inside the radiator is connected to the valve, oil pump and oil cylinder that need to be cooled.

[0012] A trenching machine hydraulic control system of the present invention has the following beneficial effects:

[0013] (1) The walking unit of the present invention can realize the independent operation of the crawler, which can not only realize the forward and reverse rotation of the crawler, but also realize the adjustable speed, thereby improving the passing capacity of the trencher.

[0014] (2) The ditching unit in the present invention can realize the forward and reverse rotation of the opening teeth, and at the same time, multiple protection designs are added to avoid equipment damage caused by sudden overload.

[0015] (3) The excavation unit in the present invention can be designed with a load variable pump and a flow control valve, which can automatically adjust the output power according to the load conditions, thereby achieving the technical goal of energy saving and high efficiency.

[0016] (4) The trenching adjustment unit in the present invention can adjust the angles of the frame and chassis to ensure vertical trenching even in uneven outdoor environments. On the other hand, it can adjust the trenching depth to facilitate operations in different environments and working conditions.

[0017] (5) The present invention is equipped with a trenching device and an excavating device, which can dig trenches on the one hand and repair the construction road surface on the other hand. The trench can also be filled by the excavating device.

[0018] (6) The trenching device of the present invention can realize continuous and uninterrupted trenching work, which improves the construction efficiency on the one hand and ensures the construction quality on the other hand. Continuous trenching can ensure the consistency of the trench. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the arrangement on the trenching machine in the present invention;

[0021] Figure 3 It is a schematic diagram of the arrangement of the leveling cylinder group on the chassis of the trencher in the present invention;

[0022] Figure 4 It is a schematic diagram of the structure of the walking unit in the present invention;

[0023] Figure 5 for Figure 4 A partial enlarged view of

[0024] Figure 6 It is a schematic diagram of the structure of the trenching unit in the present invention;

[0025] Figure 7 It is a schematic diagram of the structure of the excavation unit in the present invention;

[0026] Figure 8 for Figure 7 A partial enlarged view of

[0027] Fig. 9 It is a schematic diagram of the structure of the ditching and regulating unit in the present invention;

[0028] Fig.10 It is a schematic diagram of the structure of the heat dissipation unit in the present invention.

[0029] In the figure, 1-hydraulic oil tank, 2-travel unit, 21-motor and its switching valve group, 210-travel variable cylinder, 211-motor control valve, 212-first shuttle valve group, 214-first high-pressure relief valve, 215-travel motor, 216-travel reducer, 22-oil pump and its control valve group, 220-travel pump, 221-oil pump reversing valve, 222-second high-pressure relief valve, 223-first oil replenishment relief valve, 224-first control Oil relief valve, 225-second shuttle valve group, 3-ditching unit, 31-ditching motor, 32-ditching reducer, 33-ditching pump, 34-ditching reversing valve, 35-third high-pressure relief valve, 36-second oil replenishment relief valve, 37-second control oil relief valve, 38-third shuttle valve group, 4-excavation unit, 41-excavation pump, 42-excavation variable cylinder, 43-power control valve, 44-maximum pressure control valve, 45-pressure difference control valve, 4 6-flow control valve, 47-load feedback valve, 48-load feedback relief valve, 49-differential pressure valve, 410-pressure compensation valve, 411-excavation reversing valve, 412-fourth high-pressure relief valve, 413-left feed motor, 414-right feed motor, 415-feed switching motor, 416-leveling ditch cylinder, 417-boom cylinder, 418-bucket cylinder, 419-arm cylinder, 420-breaking hammer, 5-ditching adjustment unit, 51- regulating oil pump, 52- superimposed valve, 53- pressure control valve, 54- depth direction control valve, 55- leveling direction control valve, 56- depth oil supply valve, 57- leveling oil supply valve, 58- depth cylinder group, 59- leveling cylinder group, 6- cooling unit, 61- cooling pump, 62- cooling control valve, 63- cooling motor, 64- radiator, 7- chassis, 8- frame, 9- walking track, 10- trenching device, 11- excavation device. DETAILED DESCRIPTION

[0030] According to the accompanying drawings, the present invention is further described:

[0031] like Figure 1 As shown, a trenching machine hydraulic control system includes a hydraulic oil tank 1, a travel unit 2, a trenching unit 3, an excavation unit 4, a trenching adjustment unit 5 and a heat dissipation unit 6. The travel unit 2 is used to independently drive the travel tracks 9 installed on both sides of the chassis 7. The trenching unit 3 is used to drive the trenching device 10 to rotate. The trenching device 10 includes trenching teeth, guide wheels and driving wheels that drive the trenching teeth to move. The driving wheel is driven by a trenching motor 31 in the trenching unit 3. The excavation unit 4 is used to control the operation of the excavation device 11. The trenching adjustment unit 5 is used to adjust the angle between the chassis 7 and the frame 8 on the one hand, and to adjust the trenching depth of the trenching device 10 on the other hand. The heat dissipation unit 6 is used to dissipate heat from valves, oil pumps and oil cylinders in the hydraulic control system.

[0032] like Figure 2As shown, the trenching machine using the hydraulic control system includes a chassis 7, a frame 8, a walking track 9, a trenching device 10 and an excavating device 11. The chassis 7 and the frame 8 are connected by an articulated shaft. The top of the chassis 7 and the bottom of the frame 8 are provided with shaft holes. The trenching device 10 and the excavating device 11 are respectively arranged at both ends of the frame 8. During actual operation, the trenching device 10 and the excavating device 11 can be independently controlled and work simultaneously. The angle between the chassis 7 and the frame 8 can be adjusted to ensure that the frame 8 is always horizontal. The trenching device 10 can be adjusted by rotating around the rotating shaft of the trenching adjustment unit 5 to change the depth of burial in the soil. The speed and direction of the walking track 9 can be adjusted. Figure 2 In the embodiment, the trenching device 10 is rotatably mounted on one side of the vehicle frame 8 via a rotating shaft.

[0033] It should be noted that see Figure 3 The trenching adjustment unit 5 includes a depth-fixing cylinder group 58 and a leveling cylinder group 59. The depth-fixing cylinder group 58 consists of two cylinders with the same working state. One end of the depth-fixing cylinder group 58 is hinged on the frame 8, and the other end of the depth-fixing cylinder group 58 is hinged on the tail end of the trenching device 10. The extension and retraction of the depth-fixing cylinder group 58 can drive the trenching device 10 to rotate around the rotating shaft to adjust the depth of the trenching rack into the soil. The leveling cylinder group 59 consists of two cylinders with opposite working states. The leveling cylinder group 59 is installed between the chassis 7 and the frame 8. The bottom of the leveling cylinder group 59 is hinged on the crossbeam of the chassis 7, and the top of the leveling cylinder group 59 is hinged on the crossbeam of the frame 8. The extension and retraction of the leveling cylinder group 59 can drive the frame 8 to rotate around the hinge axis of the chassis 7 to change the horizontal angle of the frame 8.

[0034] like Figure 4 and 5 As shown, the travel unit 2 includes two sets of motors and their switching valve groups 21 and oil pumps and their control valve groups 22. The travel motor 215 in the motor and its switching valve group 21 is used to drive the travel track 9 to move, and the travel pump 220 in the oil pump and its control valve group 22 is used to drive the travel motor 215 to work;

[0035] Specifically, the motor and its switching valve group 21 in the walking unit 2 also include a walking variable cylinder 210, a motor control valve 211, a first shuttle valve group 212, a first high-pressure relief valve 214 and a walking reducer 216, wherein: the input port of the walking variable cylinder 210 is connected to the output port of the motor control valve 211, the motor control valve 211 is a two-position three-way valve, and the walking variable cylinder 210 can be adjusted by changing the position of the motor control valve 211 to drive the walking motor 215 to reduce the displacement and increase the speed of the walking motor 215. The input port of the motor control valve 211 is connected to the output port of the first shuttle valve group 212, and the input port of the shuttle valve group 212 is connected to the high-pressure oil circuit. The first high-pressure relief valve 214 is used to ensure that the walking motor is within the allowable use range, and the walking reducer 216 is connected to the walking motor 215 for reducing speed and increasing torque.

[0036] Specifically, the oil pump and its control valve group 22 in the walking unit 2 also include an oil pump reversing valve 221, a second high-pressure relief valve 222, a first oil replenishing relief valve 223, a first control oil relief valve 224 and a second shuttle valve group 225, wherein: the oil pump reversing valve 221 is used to control the vehicle to move forward or backward, the actuator cylinder of the oil pump reversing valve 221 is connected to the walking pump 220, the second high-pressure relief valve 222 is installed on the output oil circuit of the walking pump 220 for oil circuit overload unloading, the first oil replenishing relief valve 223 is used to compensate for system leakage and replenish oil to the low-pressure chamber of the closed system, and the first control oil relief valve 224 and the second shuttle valve group 225 are used to supply oil to the variable cylinder of the walking pump 220.

[0037] It should be noted that there are many control modes for the travel pump 220, such as electric control, hydraulic control, manual control, etc. This machine adopts electric control, which can realize automatic control. A speed sensor is installed on the travel motor 215, which can display the real-time travel speed of the trencher. It can be easily displayed. If unmanned operation is to be realized, it is only necessary to convert the speed signal into an electrical signal, control the output flow of the travel pump 220 through an amplifier, control the travel speed of the trencher according to different construction conditions, or set the rated speed for unmanned operation according to specific working conditions.

[0038] like Figure 6 As shown, the trenching unit 3 also includes a trenching reversing valve 34, a third high-pressure relief valve 35, a second oil replenishment relief valve 36, a second control oil relief valve 37 and a third shuttle valve group 38, wherein: the trenching reversing valve 34 is used to control the forward or reverse rotation of the trenching motor 31, the third high-pressure relief valve 35 is installed on the output oil line of the trenching motor 31 for oil line overload unloading, and the second control oil relief valve 37 and the third shuttle valve group 38 are used to supply oil to the variable oil cylinder of the trenching pump 33. Specifically, the trenching motor 31 in the trenching unit 3 provides torque to the trenching device 10 through the trenching reducer 32 to drive the trenching rack to move, and the trenching motor 31 is driven by the trenching pump 33.

[0039] like Figure 7 and Figure 8 As shown, the excavation unit 4 includes a load variable pump and a flow control valve 46. The load variable pump adjusts the output pressure according to the load conditions to achieve energy saving. The flow control valve 46 can provide real-time feedback of the load conditions to the load variable pump on the one hand, and receive the output pressure oil of the load variable pump to control the operation of the actuator on the other hand.

[0040] Specifically, the load variable pump includes an excavation pump 41, an excavation variable cylinder 42, a power control valve 43, a maximum pressure control valve 44 and a pressure difference control valve 45. The excavation variable cylinder 42 is used to adjust the output power of the excavation pump 41, the power control valve 43 is used to control the telescopic stroke of the excavation variable cylinder 42, and the maximum pressure control valve 44 and the pressure difference control valve 45 receive feedback from the load feedback valve 47 in the flow control valve 46 to control the operation of the power control valve 43.

[0041] Specifically, the flow control valve 46 includes a load feedback return valve 47, a load feedback relief valve 48, a differential pressure valve 49, multiple pressure compensation valves 410, multiple excavation reversing valves 411 and multiple fourth high-pressure relief valves 412, wherein: the load feedback return valve 47 feeds back the load condition to the load variable pump, the load feedback relief valve 48 is installed at the output port of the load feedback return valve 47, the differential pressure valve 49 is installed in the pressure oil circuit, the pressure compensation valve 410 is used to replenish oil to the working port, the excavation reversing valve 411 is a three-position six-way valve, which is used to change the direction of the oil circuit in the actuator, and the fourth high-pressure relief valve 412 can add a layer of protection to the actuator.

[0042] It should be noted that in the initial state, the load feedback valve 47 is open. When the pump port pressure rises to 14 Bar, the valve core of the pressure difference control valve 45 shifts, and the power control valve 43 controls the displacement of the excavation variable cylinder 42 to be close to zero, and the displacement of the excavation pump 41 is always maintained at a variable pressure that is just enough to maintain the oil pump; in the remote pressure control mode, when the load feedback valve 47 is opened, the pressure is released when the load pressure rises to the set pressure of the fourth high-pressure relief valve 412. When the oil pump outlet pressure rises to 114 Bar, the valve core of the pressure difference control valve 45 shifts, The power control valve 43 controls the displacement of the excavation variable cylinder 42 to be close to zero, and the displacement of the excavation pump 41 is always maintained at a variable pressure that is just enough to maintain the oil pump; during the flow reduction process, the load feedback valve 47 opening decreases, and the throttle valve inlet and outlet pressure difference increases due to the smaller opening. When it exceeds 14Bar, the valve core of the pressure difference control valve 45 shifts, and the power control valve 43 controls the displacement of the excavation variable cylinder 42 to decrease. As the displacement decreases, the pressure difference also decreases until the pressure difference is reduced to 14Bar, and the valve core of the pressure difference control valve 45 returns to the equilibrium position, and the flow remains unchanged.

[0043] It should be further explained that the excavation unit 4 also includes a left feed motor 413, a right feed motor 414, a feed switching motor 415, a groove cylinder 416, a boom cylinder 417, a bucket cylinder 418, an arm cylinder 419 and a breaker hammer 420, wherein: the left feed motor 413, the right feed motor 414, the feed switching motor 415, the groove cylinder 416, the boom cylinder 417, the bucket cylinder 418, the arm cylinder 419 and the breaker hammer 420 are respectively connected to the output port of the excavation reversing valve 411, and the mechanical structure corresponding to the excavation unit 4 adopts the existing excavation device.

[0044] The actual working of the mining unit is as follows:

[0045] When the pressure oil enters from the oil inlet, one path leads to the excavation reversing valve 411 and the other path leads to the differential pressure valve 49.

[0046] 1) When the excavation reversing valve 411 is not working: one end of the differential pressure valve 49 is connected to the load feedback port. Since there is no flow passing through the load feedback port, the load feedback valve 47 is opened. At this time, the pressure signal of the feedback port is zero. For the variable pump system, the signal of the load feedback port is also fed back to the variable pump, so that the variable pump runs at the minimum displacement and the lowest pressure and returns to the oil tank through the differential pressure valve 49. For the fixed-displacement pump system, the signal of the load feedback port is fed back to the fourth high-pressure relief valve 412 of the tail connection, so that the fixed-displacement pump is unloaded through the middle position of the tail connection at the lowest pressure.

[0047] 2) When a certain excavation reversing valve 411 is working, since the working oil pressure at the lower end of the pressure compensation valve 410 reaches the upper end of the pressure compensation valve 410 core through throttling, the working oil pressure at the lower end is high. At this time, the pressure compensation valve 410 is fully opened and no pressure compensation is performed; and the load pressure is sent to the flow control valve 46 and the load variable pump through the load oil circuit, so that the system pressure is maintained at a level slightly higher than the load pressure, thereby achieving the purpose of energy saving.

[0048] 3) When multiple excavation reversing valves 411 are working, the pressure at the load feedback port will take the one with the largest pressure among the excavation reversing valves 411, and then be fed back to the flow control valve 46 and the load variable pump as a feedback signal, thereby realizing energy-saving control and flow control, and this feedback signal acts on the upper end of the pressure compensation valve 410 core of each working link, realizing pressure compensation for the working excavation reversing valve 411 with small load, and maintaining pressure balance. At the same time, flow distribution is performed in the case of insufficient flow, thereby ensuring the stability of the action of each actuator.

[0049] When the working oil pressure at the working port is too high when it is in the middle position or when it is switching, and exceeds the set pressure of the fourth high-pressure relief valve 412, the fourth high-pressure relief valve 412 opens to release pressure to protect the actuator and other hydraulic components. When a reverse load occurs, the pressure in the working port will drop instantly or even appear in a vacuum state. At this time, the pressure compensation valve 410 will open under the action of back pressure to replenish oil to the working port. During the working switching process, or when a certain action of the fixed actuator is performed, in order to prevent the nodding problem, the two one-way valves behind the pressure compensation valve 410 work to prevent the working oil from flowing back.

[0050] like Fig. 9As shown, the ditching adjustment unit 5 also includes an adjusting oil pump 51, a stacking valve 52, a pressure control valve 53, a depth-setting direction control valve 54, a leveling direction control valve 55, a depth-setting oil replenishing valve 56 and a leveling oil replenishing valve 57, wherein: the stacking valve 52 is composed of a stacking valve block, a stacking relief valve and a high-frequency proportional reversing valve, and is used to drive the depth-setting direction control valve 54 and the leveling direction control valve 55 to change direction, the pressure control valve 53 is used for overload unloading, the depth-setting direction control valve 54 and the leveling direction control valve 55 are both two-position four-way valves used to change the oil circuit direction of the connected cylinders, the depth-setting oil replenishing valve 56 is arranged between the depth-setting direction control valve 54 and the depth-setting cylinder group 58 for oil supply, the leveling oil replenishing valve 57 is arranged between the leveling cylinder group 59 and the leveling direction control valve 55 for oil supply, and the oil circuits in the depth-setting oil replenishing valve 56 and the leveling oil replenishing valve 57 are also connected in parallel with relief valves.

[0051] It should be noted that see Figure 3 The depth-fixing cylinder group 58 is composed of two cylinders with the same working status, one end of the depth-fixing cylinder group 58 is hinged on the frame 8, and the other end of the depth-fixing cylinder group 58 is hinged on the tail end of the ditching device 10. The extension and retraction of the depth-fixing cylinder group 58 can drive the ditching device 10 to rotate around the rotating shaft to adjust the depth of the ditching rack into the soil. The leveling cylinder group 59 is composed of two cylinders with opposite working status. The leveling cylinder group 59 is installed between the chassis 7 and the frame 8. The bottom of the leveling cylinder group 59 is hinged on the crossbeam of the chassis 7, and the top of the leveling cylinder group 59 is hinged on the crossbeam of the frame 8. The extension and retraction of the leveling cylinder group 59 can drive the frame 8 to rotate around the hinge axis of the chassis 7 to change the horizontal angle of the frame 8.

[0052] like Fig.10 As shown, the heat dissipation unit 6 adopts an air cooling method, specifically including a heat dissipation pump 61, a heat dissipation control valve 62, a heat dissipation motor 63 and a radiator 64. The heat dissipation pump 61 provides power to the heat dissipation motor 63 through the heat dissipation control valve 62. The heat dissipation control valve 62 is used to control whether the heat dissipation motor 63 is working. Heat dissipation blades are arranged on the rotating shaft of the heat dissipation motor 63. The radiator 64 is close to the heat dissipation blades. The oil circuit inside the radiator 64 is connected to the valves, oil pumps and oil cylinders that need to be cooled.

[0053] Specific working process: when the radiator 64 needs to work, the control valve electromagnet is energized to drive the heat dissipation control valve 62 to work. At this time, the heat dissipation pump 61 drives the radiator motor to rotate. When the electromagnet is de-energized, the heat dissipation motor 63 stops rotating.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A trenching machine hydraulic control system, characterized in that: It comprises a hydraulic oil tank (1), a traveling unit (2), a trenching unit (3), an excavating unit (4), a trenching adjustment unit (5) and a heat dissipation unit (6), wherein: The walking unit (2) is used to independently drive walking tracks (9) installed on both sides of the chassis (7), and the walking unit (2) comprises two sets of motors and their switching valve groups (21) and an oil pump and its control valve group (22), the walking motor (215) in the motor and its switching valve group (21) is used to drive the walking tracks (9) to move, and the walking pump (220) in the oil pump and its control valve group (22) is used to drive the walking motor (215) to work; The ditching unit (3) is used to drive the ditching device (10) to rotate. The ditching device (10) is rotatably mounted on one side of the frame (8) via a rotating shaft. The ditching motor (31) in the ditching unit (3) provides torque to the ditching device (10) via a ditching reducer (32) to drive the ditching rack to move. The ditching motor (31) is driven by a ditching pump (33); The excavating unit (4) is used to control the operation of an excavating device (11), wherein the excavating device (11) is mounted on the other side of the vehicle frame (8); The trenching adjustment unit (5) is used to adjust the angle between the chassis (7) and the frame (8) on the one hand, and to adjust the trenching depth of the trenching device (10) on the other hand. The trenching adjustment unit (5) comprises a depth-fixing cylinder group (58) and a leveling cylinder group (59). The depth-fixing cylinder group (58) is composed of two cylinders with the same working state. One end of the depth-fixing cylinder group (58) is hinged on the frame (8), and the other end of the depth-fixing cylinder group (58) is hinged on the rear end of the trenching device (10). The extension and retraction of the depth-fixing cylinder group (58) can be adjusted. The ditching device (10) is driven to rotate around the rotating shaft to adjust the depth of the ditching rack into the soil. The leveling cylinder group (59) is composed of two cylinders with opposite working states. The leveling cylinder group (59) is installed between the chassis (7) and the frame (8). The bottom of the leveling cylinder group (59) is hinged on the crossbeam of the chassis (7), and the top of the leveling cylinder group (59) is hinged on the crossbeam of the frame (8). The extension and retraction of the leveling cylinder group (59) can drive the frame (8) to rotate around the hinge axis of the chassis (7) to change the horizontal angle of the frame (8); The heat dissipation unit (6) is used for dissipating heat from valves, oil pumps, and oil cylinders in a hydraulic control system; The trenching unit (3) further comprises a trenching reversing valve (34), a third high-pressure relief valve (35), a second oil replenishment relief valve (36), a second control oil relief valve (37) and a third shuttle valve group (38), wherein: The trenching reversing valve (34) is used to control the forward or reverse rotation of the trenching motor (31); the third high-pressure relief valve (35) is installed on the output oil circuit of the trenching motor (31) to unload the oil circuit overload; the second control oil relief valve (37) and the third shuttle valve group (38) are used to supply oil to the variable oil cylinder of the trenching pump (33); The trenching regulating unit (5) further comprises a regulating oil pump (51), a stacking valve (52), a pressure control valve (53), a depth-setting direction control valve (54), a leveling direction control valve (55), a depth-setting oil replenishment valve (56) and a leveling oil replenishment valve (57), wherein: The stacking valve (52) is composed of a stacking valve block, a stacking relief valve and a high-frequency proportional reversing valve, and is used to drive the depth-setting direction control valve (54) and the leveling direction control valve (55) to switch directions. The pressure control valve (53) is used for overload unloading. The depth-setting direction control valve (54) and the leveling direction control valve (55) are both two-position four-way valves used to change the direction of the oil circuit of the connected oil cylinder. The depth-setting oil replenishing valve (56) is arranged between the depth-setting direction control valve (54) and the depth-setting oil cylinder group (58) for oil supply. The leveling oil replenishing valve (57) is arranged between the leveling oil cylinder group (59) and the leveling direction control valve (55) for oil supply. Relief valves are also connected in parallel in the oil circuits of the depth-setting oil replenishing valve (56) and the leveling oil replenishing valve (57).

2. The trencher hydraulic control system according to claim 1, characterized in that: The motor and the switching valve group (21) in the travel unit (2) further include a travel variable oil cylinder (210), a motor control valve (211), a first shuttle valve group (212), a first high-pressure relief valve (214) and a travel reducer (216), wherein: The input port of the travel variable oil cylinder (210) is connected to the output port of the motor control valve (211); the motor control valve (211) is a two-position three-way valve; the travel variable oil cylinder (210) can be adjusted by changing the position of the motor control valve (211) to drive the travel motor (215) to reduce the displacement and increase the speed of the travel motor (215); the input port of the motor control valve (211) is connected to the output port of the first shuttle valve group (212); the input port of the shuttle valve group (212) is connected to the high-pressure oil circuit; the first high-pressure relief valve (214) is used to ensure that the travel motor is within the permitted use range; the travel reducer (216) is connected to the travel motor (215) to reduce speed and increase torque; The oil pump and its control valve group (22) in the travel unit (2) further comprise an oil pump reversing valve (221), a second high-pressure relief valve (222), a first oil replenishment relief valve (223), a first control oil relief valve (224) and a second shuttle valve group (225), wherein: The oil pump reversing valve (221) is used to control the vehicle to move forward or backward. The actuating oil cylinder of the oil pump reversing valve (221) is connected to the travel pump (220). The second high-pressure relief valve (222) is installed on the output oil circuit of the travel pump (220) to unload the oil circuit overload. The first oil replenishment relief valve (223) is used to compensate for system leakage and replenish oil to the low-pressure chamber of the closed system. The first control oil relief valve (224) and the second shuttle valve group (225) are used to supply oil to the variable oil cylinder of the travel pump (220).

3. The trencher hydraulic control system according to claim 1, characterized in that: The excavation unit (4) comprises a load variable pump and a flow control valve (46). The load variable pump adjusts the output pressure according to the load condition to achieve energy saving. The flow control valve (46) can, on the one hand, provide real-time feedback of the load condition to the load variable pump, and on the other hand, receive the output pressure oil of the load variable pump to control the operation of the actuator. The load variable pump comprises an excavation pump (41), an excavation variable oil cylinder (42), a power control valve (43), a maximum pressure control valve (44) and a pressure difference control valve (45). The excavation variable oil cylinder (42) is used to adjust the output power of the excavation pump (41). The power control valve (43) is used to control the telescopic stroke of the excavation variable oil cylinder (42). The maximum pressure control valve (44) and the pressure difference control valve (45) receive the feedback of the load feedback valve (47) in the flow control valve (46) to control the operation of the power control valve (43). The flow control valve (46) includes a load feedback return valve (47), a load feedback relief valve (48), a differential pressure valve (49), a plurality of pressure compensation valves (410), a plurality of excavation reversing valves (411), and a plurality of fourth high-pressure relief valves (412), wherein: the load feedback return valve (47) feeds back the load condition to the load variable pump, the load feedback relief valve (48) is installed at the output port of the load feedback return valve (47), the differential pressure valve (49) is installed on the pressure oil circuit, the pressure compensation valve (410) is used to replenish oil to the working port, and the excavation reversing valve (411) is a three-position six-way valve, which is used to change the direction of the oil circuit in the actuator.

4. The trencher hydraulic control system according to claim 3, characterized in that: The excavation unit (4) further comprises a left feed motor (413), a right feed motor (414), a feed switching motor (415), a leveling cylinder (416), a boom cylinder (417), a bucket cylinder (418), a dipper arm cylinder (419) and a breaker hammer (420), wherein: The left feed motor (413), the right feed motor (414), the feed switching motor (415), the trenching cylinder (416), the boom cylinder (417), the bucket cylinder (418), the arm cylinder (419) and the breaker hammer (420) are respectively connected to the output port of the excavation reversing valve (411).

5. The trencher hydraulic control system according to claim 1, characterized in that: The heat dissipation unit (6) comprises a heat dissipation pump (61), a heat dissipation control valve (62), a heat dissipation motor (63) and a radiator (64); the heat dissipation pump (61) provides power to the heat dissipation motor (63) via the heat dissipation control valve (62); the heat dissipation control valve (62) is used to control whether the heat dissipation motor (63) is working; a heat dissipation fan blade is arranged on the rotating shaft of the heat dissipation motor (63); the radiator (64) is close to the heat dissipation fan blade; and the oil circuit inside the radiator (64) is connected to the valve, oil pump and oil cylinder that need to be cooled.

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