A hydraulic control system of a digging type pipe dredging vehicle, the digging type pipe dredging vehicle and a control method thereof

Abstract

The present application belongs to the technical field of pipe network dredging equipment, and discloses a hydraulic control system of a digging type pipe dredging vehicle, the digging type pipe dredging vehicle and a control method thereof, wherein the system comprises a hydraulic oil tank, a gear pump, a proportional multi-way valve, a rotary motor, an arm frame amplitude cylinder, an arm frame telescopic cylinder and a winch motor; the oil outlet of the hydraulic oil tank is connected with the oil inlet of the gear pump; the oil outlet of the gear pump is connected with the oil inlet of the proportional multi-way valve; the oil outlets of the proportional multi-way valve are respectively connected with the oil inlets and outlets of the rotary motor, the arm frame amplitude cylinder, the arm frame telescopic cylinder and the winch motor; and the oil return port of the proportional multi-way valve is connected with the oil inlet of the hydraulic oil tank. The present application realizes the synchronous action and stepless speed regulation of the four executing mechanisms of the rotary motor, the arm frame amplitude cylinder, the arm frame telescopic cylinder and the winch motor, and is not affected by the change of external load.

Description

Technical Field

[0001] This invention belongs to the technical field of pipeline dredging equipment, and particularly relates to a hydraulic control system for a digging-type pipeline dredging vehicle, the digging-type pipeline dredging vehicle and its control method. Background Technology

[0002] Excavator-type pipe dredging trucks are suitable for cleaning various types of wells, sedimentation wells, and septic tanks in urban municipalities, industrial and mining enterprises, and residential communities. They can effectively and quickly remove various types of silt accumulated in wells, effectively reducing the labor intensity of workers.

[0003] Currently, excavating pipe dredging trucks on the market load and unload sludge by controlling the three-dimensional spatial movement of the sludge grab bucket. There are two types: hydraulic control and pure electric control. Excavating pipe dredging trucks using hydraulic systems to control the sludge grab bucket have a wider market scale and application range. In the industry, the hydraulic systems of excavating pipe dredging trucks mostly adopt open hydraulic systems consisting of gear pumps, electrically integrated valve groups, actuator cylinders, and motors.

[0004] The hydraulically controlled dredging grab bucket of the excavating pipeline dredging vehicle mainly consists of an electrically controlled integrated valve group, chassis, base, sludge tank, boom assembly, winch mechanism, and dredging grab bucket. The boom assembly is fixed to the chassis via the base, which contains a rotary motor. The boom assembly includes a fixed boom, boom luffing cylinder, telescopic boom, and boom telescopic cylinder. The winch mechanism is fixed to the telescopic boom and contains a winch motor. The movable end of the wire rope is connected to the dredging grab bucket, which contains a grab bucket cylinder. During operation, the control valve group controls the rotary motor to rotate, causing the base to rotate and drive the boom assembly to rotate; the boom luffing cylinder extends, raising the telescopic boom; the boom telescopic cylinder extends, extending the telescopic boom; the winch motor rotates, causing the winch mechanism's wire rope to release, lowering the dredging grab bucket into the sewer manhole. After the grab bucket is filled with silt, the winch mechanism retracts the rope, the boom retracts, and the slewing motor rotates in the opposite direction, aligning the grab bucket with the sludge tank. The grab bucket then opens, completing one cycle. To prevent damage to the wire rope from overwinding, an anti-overwinding sensor is installed on the side of the telescopic boom near the dredging grab bucket.

[0005] The aforementioned electrically controlled integrated valve groups are either on / off type integrated valve groups or integrated valve groups with electromagnetic proportional valves used in some working links. The operating speed of each actuator controlled by the on / off type integrated valve group can only be adjusted by the chassis engine speed. The operating speed of each actuator controlled by the electromagnetic proportional valve integrated valve group with some working links can only be switched between a limited number of speed values ​​by preset different current values ​​of the electromagnetic coil of the electromagnetic proportional valve. In situations where the amount of sludge accumulated in the manhole is relatively large, this presents a technical drawback: operators cannot flexibly adjust the operating speed of each actuator, thus hindering work efficiency.

[0006] Furthermore, the hydraulic systems of commercially available dredging and excavating pipe cleaning trucks can only achieve individual operation of each actuator or at most two actuators combined operation. This results in slow movement of the dredging grab bucket, and significant swaying of the boom and dredging grab bucket when switching between the four actions: boom extension / retraction, boom luffing / lifting, winch motor rope winding / unwinding, and slewing motor rotation. Especially when the load on the actuators varies greatly, such as a 20kg difference in the amount of sludge grabbed by the dredging grab bucket in two separate grabs, the synchronization of the boom extension / retraction and winch motor rope winding, which were originally capable of combined operation, deteriorates, and the original work efficiency cannot be maintained. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hydraulic control system for a digging-type pipe dredging vehicle, a digging-type pipe dredging vehicle and its control method, so as to realize the synchronous action and stepless speed regulation of four actuators: slewing motor, boom luffing cylinder, boom telescopic cylinder and winch motor, and to be unaffected by changes in external load.

[0008] To solve the above-mentioned technical problems, the present invention is implemented using the following solution: This invention provides a hydraulic control system for a digging-type pipeline dredging vehicle, comprising: an oil outlet of a hydraulic oil tank connected to an oil inlet of a gear pump; an oil outlet of the gear pump connected to an oil inlet of a proportional multi-way valve; an oil outlet of the proportional multi-way valve connected to the oil inlet and outlet of a rotary motor, a boom luffing cylinder, a boom telescopic cylinder, and a winch motor, respectively; and a return port of the proportional multi-way valve connected to the oil inlet of the hydraulic oil tank. The proportional multi-way valve includes a three-way flow control valve, four electromagnetic proportional directional valves, four two-way flow control valves, and four shuttle valves. The inlet of the proportional multi-way valve is connected to the inlet of the three-way flow control valve, the inlet of the two-way flow control valve, and the non-spring side of the valve core of the three-way flow control valve. The outlet of the three-way flow control valve is connected to the return port of the proportional multi-way valve. The outlet of the two-way flow control valve is connected to the inlet of the electromagnetic proportional directional valve and the non-spring side of the valve core of the two-way flow control valve. The outlet of the electromagnetic proportional directional valve is connected to the slewing motor, the boom luffing cylinder, the boom telescopic cylinder, and... The inlet and outlet ports of the hoist motor, the first inlet port of the shuttle valve, and the valve core spring side end face of the two-way flow valve are connected. The second inlet port of the shuttle valve is connected to the outlet port of another shuttle valve. The outlet port of the shuttle valve is connected to the valve core spring side end face of the three-way flow regulating valve and the valve core spring side end face of the electromagnetic proportional directional valve. The return port of the electromagnetic proportional directional valve is connected to the return port of the proportional multi-way valve. When the electromagnetic proportional directional valve is energized, the pressure value of the inlet port of the proportional multi-way valve is equal to the maximum load pressure of the slewing motor, the boom luffing cylinder, the boom telescopic cylinder, and the hoist motor plus a fixed value.

[0009] Furthermore, when the electromagnetic proportional directional valve is not energized, the valve core spring side end face of the two-way flow valve is connected to the oil return port of the proportional multi-way valve; when the electromagnetic proportional directional valve is energized, the valve core spring side end face of the two-way flow valve is disconnected from the oil return port of the proportional multi-way valve.

[0010] Furthermore, the proportional multi-way valve also includes a pressure relief valve, the inlet of which is connected to the inlet of the proportional multi-way valve, and the outlet of which is connected to the return port of the proportional multi-way valve.

[0011] Furthermore, the proportional multi-way valve also includes a filter and a three-way pressure reducing valve. The oil inlet of the filter is connected to the oil inlet of the proportional multi-way valve, the oil inlet of the three-way pressure reducing valve is connected to the oil outlet of the filter, the first oil outlet of the three-way pressure reducing valve is connected to the oil return port of the proportional multi-way valve, and the second oil outlet of the three-way pressure reducing valve is connected to the valve core spring side end face of the electromagnetic proportional directional valve.

[0012] Furthermore, the proportional multi-way valve also includes an LS control valve and a damping assembly. The outlet of the shuttle valve is connected to the inlet of the damping assembly, the outlet of the damping assembly is connected to the inlet of the LS control valve and the valve core spring side end face of the three-way flow regulating valve, and the outlet of the LS control valve is connected to the valve core spring side end face of the electromagnetic proportional directional valve. When the LS control valve is not energized, its inlet and outlet are open, and when the LS control valve is energized, its inlet and outlet are closed.

[0013] Furthermore, it also includes a grab cylinder, with the outlet of the proportional multi-way valve connected to the inlet and outlet of the grab cylinder, and the outlet of the electromagnetic proportional directional valve connected to the inlet and outlet of the grab cylinder.

[0014] Furthermore, it also includes a selector valve, the inlet and outlet of which are connected to the outlet of a proportional multi-way valve, and the outlet of the selector valve is connected to the inlet and outlet of the winch motor and the grab cylinder, respectively.

[0015] The present invention also provides a digging-type pipe dredging vehicle, including a telescopic boom, a winch mechanism, a sludge grab bucket and a base, wherein the digging-type pipe dredging vehicle is equipped with the aforementioned digging-type pipe dredging vehicle hydraulic control system.

[0016] The present invention also provides a control method for a digging-type pipe dredging vehicle, characterized in that it includes: When the excavating pipeline dredging truck stops in front of the manhole, the electromagnetic proportional directional valve is energized and reversed. The hydraulic oil is drawn from the hydraulic oil tank by the gear pump and enters the two-way flow valve and the three-six flow regulating valve through the proportional multi-way valve. The hydraulic oil exits the two-way flow valve and flows through the electromagnetic proportional directional valve to the working chamber of the slewing motor, boom luffing cylinder, boom telescopic cylinder, and winch motor, as well as the first oil inlet acting on the shuttle valve. The hydraulic oil in the other working chamber of the slewing motor, boom luffing cylinder, boom telescopic cylinder, and winch motor flows back to the oil tank through the electromagnetic proportional directional valve and the proportional multi-way valve, realizing a compound movement of the base, telescopic boom, and winch mechanism, and lowering the dredging grab bucket to open and close to grab the silt at the bottom of the manhole. After the sludge is completely grabbed, the electromagnetic proportional directional valve is de-energized and reversed again. The hydraulic oil is drawn from the hydraulic oil tank by the gear pump and enters the two-way flow valve and the three-six flow regulating valve through the proportional multi-way valve. The hydraulic oil exits the two-way flow valve and flows through the electromagnetic proportional directional valve to the other working chamber of the slewing motor, boom luffing cylinder, boom telescopic cylinder, and winch motor, as well as the first oil inlet acting on the shuttle valve. The hydraulic oil in one working chamber of the slewing motor, boom luffing cylinder, boom telescopic cylinder, and winch motor flows back to the oil tank through the electromagnetic proportional directional valve and proportional multi-way valve, realizing a secondary compound movement of the base, telescopic boom, and winch mechanism. The sludge grab bucket opens and unloads the sludge into the sludge tank.

[0017] Furthermore, it also includes: When the excavating pipe dredging vehicle stops in front of the manhole, the outrigger cylinders extend. The first compound motion includes: the horizontal extension of the telescopic boom and the vertical luffing lifting, the horizontal rotation of the base driving the rotation of the fixed boom, and the winch mechanism releasing the rope; the second compound motion includes: the horizontal retraction of the telescopic boom and the vertical luffing descent, the horizontal rotation of the base driving the rotation of the fixed boom, and the winch mechanism retracting the rope. Beneficial effects

[0018] This invention can adjust the current value of the electromagnetic coil of the electromagnetic proportional directional valve in the proportional multi-way valve, so that the flow of the electromagnetic proportional directional valve changes, thereby realizing stepless speed regulation of any one or more of the four actuators: the slewing motor, the boom luffing cylinder, the boom telescopic cylinder, and the winch motor, increasing the flexibility and coordination of the dredging grab bucket movement.

[0019] When the electromagnetic proportional directional valve in the proportional multi-way valve of this invention is energized, the pressure value at the inlet of the proportional multi-way valve is equal to the maximum load pressure of the slewing motor, boom luffing cylinder, boom telescopic cylinder, and winch motor plus a fixed value. Therefore, the four actuators of the slewing motor, boom luffing cylinder, boom telescopic cylinder, and winch motor can be operated synchronously. Furthermore, when the load of the actuator changes, the hydraulic system can automatically adjust the system pressure without affecting the synchronization of the actuators, thus improving work efficiency and reducing the sway of the boom and dredging grab, thereby improving the stability of movement. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a hydraulic control system for a digging-type pipe dredging vehicle based on the load-sensing principle, provided in Embodiment 1 of the present invention; Figure 2 This is a front view structural schematic diagram of a digging-type pipe dredging vehicle according to Embodiment 2 of the present invention; Figure 3 This is a top view of a digging-type pipe dredging vehicle according to Embodiment 2 of the present invention; In the diagram: 1. Hydraulic oil tank; 2. Gear pump; 3. Proportional multi-way valve; 4. LS control valve; 5. Damping assembly; 6. Three-way flow regulating valve; 7. Pressure limiting valve; 8. Filter; 9. Three-way pressure reducing valve; 10. Slewing motor; 11. First electromagnetic proportional directional valve; 12. First two-way flow valve; 13. Boom luffing cylinder; 14. Second electromagnetic proportional directional valve; 15. Second two-way flow valve; 16. Boom telescopic cylinder; 17. Third electromagnetic proportional directional valve. 18. Third two-way flow valve; 19. Winch motor; 20. Grab cylinder; 21. Selector valve; 22. Fourth electromagnetic proportional directional valve; 23. Fourth two-way flow valve; 24. First shuttle valve; 25. Second shuttle valve; 26. Third shuttle valve; 27. Fourth shuttle valve; 28. Chassis; 29. ​​Sludge tank; 30. Telescopic boom; 31. Winch mechanism; 32. Fixed boom; 33. Outrigger cylinder; 34. Overwind sensor; 35. Dredging grab bucket; 36. Base. Detailed Implementation

[0021] 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 solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0022] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] like Figure 1As shown, one embodiment of the present invention provides a hydraulic control system for a digging-type pipeline dredging vehicle based on the load-sensitive principle, which consists of a hydraulic oil tank 1, a gear pump 2, a proportional multi-way valve 3, a rotary motor 10, a boom luffing cylinder 13, a boom telescopic cylinder 16, a winch motor 19, a grab bucket cylinder 20, and a selector valve 21.

[0024] Specifically, the outlet of the hydraulic oil tank 1 is connected to the inlet of the gear pump 2; the outlet of the gear pump 2 is connected to the inlet of the proportional multi-way valve 3; the outlet of the proportional multi-way valve 3 is connected to the inlet and outlet of the slewing motor 10, the boom luffing cylinder 13, the boom telescopic cylinder 16, and the selector valve 21 respectively; the outlet of the selector valve 21 is connected to the inlet and outlet of the winch motor 19 and the grab cylinder 20 respectively; and the return port of the proportional multi-way valve 3 is connected to the inlet of the hydraulic oil tank 1. The hydraulic oil tank 1 stores hydraulic oil and cools the hydraulic system; the gear pump 2 provides power to the hydraulic system; the proportional multi-way valve 3 allows hydraulic oil to be input into the slewing motor 4, boom luffing cylinder 13, boom telescopic cylinder 16, and selector valve 21, and output from the outlet; the selector valve 21 acts as a directional valve, allowing hydraulic oil to be input into the winch motor 19 or grab cylinder 20 and output from the return port; the slewing motor 4 controls the horizontal forward and reverse rotation of the base 36; the boom luffing cylinder 13 controls the vertical lifting of the telescopic boom 30; the boom telescopic cylinder 16 controls the horizontal extension and retraction of the telescopic boom 30; the winch motor 19 controls the forward and reverse rotation of the winch mechanism 31; and the grab cylinder 20 controls the opening and closing of the dredging grab 35.

[0025] Furthermore, the proportional multi-way valve 3 is composed of an LS control valve 4, a damping assembly 5, a three-way flow regulating valve 6, a pressure limiting valve 7, a filter 8, a three-way pressure reducing valve 9, a first electromagnetic proportional directional valve 11, a first two-way flow valve 12; a second electromagnetic proportional directional valve 14, a second two-way flow valve 15, a third electromagnetic proportional directional valve 17, a third two-way flow valve 18, a fourth electromagnetic proportional directional valve 22, a fourth two-way flow valve 23, a first shuttle valve 24, a second shuttle valve 25, a third shuttle valve 26, and a fourth shuttle valve 27.

[0026] More specifically, the oil inlet of the proportional multi-way valve 3 is connected to the oil inlets of the three-way flow regulating valve 6, the pressure limiting valve 7, the filter 8, the first two-way flow valve 12, the second two-way flow valve 15, the third two-way flow valve 18, and the fourth two-way flow valve 23, as well as the non-spring side end face of the valve core of the three-way flow regulating valve 6; the oil outlet of the filter 8 is connected to the oil inlet of the three-way pressure reducing valve 9; and the oil outlets of the three-way flow regulating valve 6, the pressure limiting valve 7, and the three-way pressure reducing valve 9 are connected to the oil return port of the proportional multi-way valve 3.

[0027] More specifically, taking the first working connection as an example, the oil outlet of the first two-way flow valve 12 is connected to the oil inlet of the first electromagnetic proportional directional valve 11 and the non-spring side end face of the valve core of the first two-way flow valve 12; the two oil outlets of the first electromagnetic proportional directional valve 11 are connected to the oil inlet and outlet of the rotary motor 10, the first oil inlet of the first shuttle valve 24, and the spring side end face of the valve core of the first two-way flow valve 12; the second oil inlet of the first shuttle valve 24 is connected to the oil outlet of the second shuttle valve 25, and the oil outlet of the first shuttle valve 24 is connected to the oil inlet of the damping assembly 5; the oil outlet of the damping assembly 5 is connected to the oil inlet of the LS control valve 4 and the spring side end face of the valve core of the three-way flow regulating valve 6. The oil outlet of the LS control valve 4 is connected to the valve core spring side face of the first electromagnetic proportional directional valve 11, the second electromagnetic proportional directional valve 14, the third electromagnetic proportional directional valve 17, and the fourth electromagnetic proportional directional valve 22, respectively. When the LS control valve 4 is not energized, its inlet and outlet ports are connected; when the LS control valve 4 is energized, its inlet and outlet ports are disconnected. The oil return port of the first electromagnetic proportional directional valve 11 is connected to the oil return port of the proportional multi-way valve 3. When the first electromagnetic proportional directional valve 11 is not energized, the valve core spring side face of the first two-way flow valve 12 is connected to the oil return port of the proportional multi-way valve 3; when the first electromagnetic proportional directional valve 11 is energized, the valve core spring side face of the first two-way flow valve 12 is disconnected from the oil outlet port of the proportional multi-way valve 3.

[0028] The oil circuit connection relationship of the second electromagnetic proportional directional valve 14, the third electromagnetic proportional directional valve 17, and the fourth electromagnetic proportional directional valve 22 is similar to the oil circuit connection relationship of the first electromagnetic proportional directional valve 11 mentioned above.

[0029] More specifically, the valve core of any electromagnetic proportional directional valve has multiple channels on its cylindrical surface for hydraulic oil flow. In this invention, the channels on the valve core of any electromagnetic proportional directional valve are not interconnected, and the cross-sectional areas of the cylindrical surfaces are identical. Any shuttle valve has two inlets and one outlet, and the pressure of the oil flowing out of the outlet is the same as the pressure of the hydraulic oil at the larger of the two inlets. The filter 8 prevents the three-way pressure reducing valve 9 from jamming or wearing due to impurities.

[0030] In addition, the hydraulic control system includes a remote controller and a control unit. The control unit receives signals from the remote controller and is electrically connected to both the proportional multi-way valve 3 and the selector valve 21. The remote controller has four operating handles and four operating buttons. The four operating handles control the rotation of the slewing motor, the raising and lowering of the telescopic boom, the extension and retraction of the telescopic boom, and the retraction and extension of the winch motor. The four operating buttons control the opening and closing of the grab bucket, the acceleration of the chassis engine, the switching on and off of the lights, and a spare button.

[0031] The control principle of the hydraulic control system for load-sensitive excavating pipe dredging trucks is explained below in three scenarios: (1) The gear pump is running and no actuator is operating. In this operating condition, the proportional multi-way valve 3 is not energized, the gear pump 2 draws oil from the hydraulic oil tank 1, and the hydraulic oil flows through the outlet of the hydraulic oil tank 1, the inlet and outlet of the gear pump 2, and the inlet of the proportional multi-way valve 3 to the non-spring side end face and cylindrical surface of the three-way flow regulating valve 6. Furthermore, since the LS control valve 4 is not energized, the LS control valve 4 is in a hydraulic oil flowable state, and the LS passage is unloaded. The hydraulic oil on the spring side end face of the three-way flow regulating valve 6 is basically pressureless. When the hydraulic oil pressure acting on the non-spring side end face of the three-way flow regulating valve 6 is greater than the spring force, the hydraulic oil pushes the valve core of the three-way flow regulating valve 6 to move towards the spring side. The hydraulic oil acting on the cylindrical surface of the three-way flow regulating valve 6 can flow through the valve core passage, the outlet of the proportional multi-way valve 3, and the return port of the hydraulic oil tank 1 back to the oil tank. The hydraulic system is in a pump idling circulation state.

[0032] (2) Operation of a single executing agency Taking the clockwise rotation of the rotary motor as an example, when the coils of the first electromagnetic proportional directional valve 11 and the LS control valve 4 are energized, the valve core of the first electromagnetic proportional directional valve 11 moves towards the spring side against the spring force under the action of the electromagnetic force of the coil. The gear pump 2 draws oil from the hydraulic oil tank 1, and the hydraulic oil flows through the outlet of the hydraulic oil tank 1, the inlet and outlet of the gear pump 2, the inlet of the proportional multi-way valve 3, and reaches the inlet of the first two-way flow control valve 12, the cylindrical surface and non-spring side end face of the valve core of the three-way flow regulating valve 6, the inlet of the pressure limiting valve 7, and the inlet of the three-way pressure reducing valve 9. Step by step, the hydraulic oil from the outlet of the first two-way flow valve 12 is divided into four paths: the first path of hydraulic oil flows through the valve core cylindrical hole channel of the first electromagnetic proportional directional valve 11 to the inlet of the rotary motor 10; the second path of hydraulic oil reaches the non-spring side end face of the valve core of the first two-way flow valve 12; the third path of hydraulic oil flows through the valve core cylindrical hole channel of the first electromagnetic proportional directional valve 11 and acts on the spring side end face of the valve core of the first two-way flow valve 12; the fourth path of hydraulic oil flows through the valve core cylindrical hole channel of the first electromagnetic proportional directional valve 11 and acts on the first inlet of the first shuttle valve 24.

[0033] Furthermore, the rotary motor 10 rotates clockwise under the push of hydraulic oil. The hydraulic oil in the cavity of the rotary motor 10 flows out from the oil outlet and returns to the oil tank through the valve core cylindrical channel of the first electromagnetic proportional directional valve 11, the oil outlet of the proportional multi-way valve 3, and the oil return port of the hydraulic oil tank 1. The valve core of the first two-way flow valve 12 is dynamically balanced under the action of the hydraulic oil force on the spring side end face and the hydraulic oil force on the non-spring side end face, as well as the elastic force of the spring. Due to the pressure of the hydraulic oil on the non-spring side end face and the oil inlet of the valve core cylindrical channel of the first electromagnetic proportional directional valve 11, the valve core of the first two-way flow valve 12 is in dynamic equilibrium. The pressure values ​​of the hydraulic oil at the spring side end face of the first two-way flow valve 12 and the oil outlet of the valve core cylindrical hole of the first electromagnetic proportional directional valve 11 are the same, and the end face areas of the valve core on both sides of the first two-way flow valve 12 are the same. Therefore, the pressure difference between the inlet and outlet of the valve core cylindrical hole of the first electromagnetic proportional directional valve 11 is the same and equal to the quotient of the spring force of the first two-way flow valve 12 and the end face area of ​​the valve core. According to the hydraulic resistance theorem, under the same pressure difference, the flow rate of hydraulic oil through the valve core cylindrical hole of the first electromagnetic proportional directional valve 11 is determined by the cross-sectional area of ​​the valve core cylindrical hole.

[0034] Furthermore, the hydraulic oil flows from the outlet of the first shuttle valve 24 through the damping assembly 5 to the inlet of the LS control valve 4 and the spring side end face of the valve core of the three-way flow regulating valve 6. Because the solenoid coil of the LS control valve 4 is energized, the LS control valve 4 is shut off. The valve core of the three-way flow control valve 6 is dynamically balanced under the action of hydraulic oil on the spring side end face, hydraulic oil on the non-spring side end face, and the elastic force of the spring. Since the action force on the spring side end face of the valve core of the three-way flow control valve 6 is equal to the inlet pressure of the rotary motor 10 plus the pressure loss of the valve core cylinder orifice of the first electromagnetic proportional directional valve 11, as well as the pressure loss of the flow channel and the shuttle valve, the action force on the non-spring side end face of the valve core of the three-way flow control valve 6 is the same as the inlet pressure of the proportional multi-way valve 3. That is, the inlet pressure of the proportional multi-way valve 3 is equal to the inlet pressure of the rotary motor 10 plus the pressure loss of the valve core cylinder orifice of the first electromagnetic proportional directional valve 11, as well as the pressure loss of the flow channel and the first shuttle valve 24, plus the spring force of the three-way flow control valve 6. More specifically, the inlet pressure of the proportional multi-way valve 3 is higher than the load pressure of the rotary motor 10 by a fixed value.

[0035] Furthermore, when the inlet pressure of the proportional multi-way valve 3 is equal to the set pressure of the pressure relief valve 7, the hydraulic oil returns to the oil tank through the inlet and outlet of the pressure relief valve 7, the outlet of the proportional multi-way valve 3, and the return port of the hydraulic oil tank 1, causing the hydraulic system to overflow and the rotary motor 10 to stop rotating; the outlet of the three-way pressure reducing valve 9 outputs hydraulic oil with a pressure 20 bar lower than that of the inlet of the proportional multi-way valve 3, which acts on the valve core end face of the first electromagnetic proportional directional valve 11 as control oil.

[0036] In summary, since the cross-sectional area of ​​the valve core cylindrical channel of the first electromagnetic proportional directional valve 11 is different when the current value of the coil of the first electromagnetic proportional directional valve 11 is different, the flow rate of the first electromagnetic proportional directional valve changes accordingly according to the liquid resistance theorem. Thus, the rotation speed of the rotary motor 10 can be infinitely adjusted by adjusting the current value of the electromagnetic coil of the first electromagnetic proportional directional valve 11.

[0037] (3) Multiple execution agencies operate simultaneously Because the action time of the grab cylinder is short, combining it with other actuators does not meet the needs of actual working scenarios. Therefore, this invention only realizes the synchronous action of any one or more of the four actuators: slewing motor 10, boom luffing cylinder 13, boom telescopic cylinder 16, and winch motor 19. Taking the clockwise rotation of slewing motor 10 and the extension of boom luffing cylinder 13 as an example, the load of the extended boom luffing cylinder 13 is set to be greater than the load of the clockwise rotation of slewing motor 10.

[0038] When the first electromagnetic proportional directional valve 11 and the second electromagnetic proportional directional valve 14 are energized, the valve cores of the first electromagnetic proportional directional valve 11 and the second electromagnetic proportional directional valve 14 move towards the spring side under the action of the electromagnetic force of the coil, overcoming the spring force. The flow direction of the hydraulic oil is similar to that of (2) above. The difference is that the outlet pressure of the first shuttle valve 24 is equal to the load pressure of the boom luffing cylinder 13 plus the flow channel pressure loss and the pressure loss of the first shuttle valve 24 and the second shuttle valve 25. That is, the spring side pressure acting on the three-way flow regulating valve 6 is higher than the load pressure of the boom luffing cylinder 13 by a fixed value. Since the spring side pressure of the hydraulic oil acting on the three-way flow regulating valve 6 is the same as the inlet pressure of the proportional multi-way valve 3, when the slewing motor 10 rotates clockwise and the boom luffing cylinder 13 extends, the inlet pressure of the proportional multi-way valve 3 is the larger value of the load of the two actuators plus a fixed value. When the load of the actuator changes, the hydraulic system can dynamically adjust the inlet pressure of the proportional multi-way valve 3.

[0039] In summary, when the solenoid coils of the multiple electromagnetic proportional directional valves in a proportional multi-way valve are energized, the pressure value at the inlet of the proportional multi-way valve is equal to the maximum load pressure among the multiple actuators plus a fixed value. This ensures the synchronous operation of the multiple actuators and is unaffected by load changes. This control method is hydraulic proportional control based on the load-sensitive principle.

[0040] In summary, the hydraulic control system of the excavating pipeline dredging vehicle based on the load-sensitive principle designed in this invention can achieve stepless speed regulation and synchronous operation of any one or more of the four actuators: the slewing motor, the boom luffing cylinder, the boom telescopic cylinder, and the winch motor. Furthermore, since it does not require frequent switching of the actuators, it reduces the sway of the boom and the dredging grab bucket, thereby improving the stability of the movement.

[0041] like Figure 2 and Figure 3 As shown, another embodiment of the present invention provides a digging-type pipe dredging vehicle equipped with a hydraulic control system for digging-type pipe dredging vehicles, and also includes a chassis 28, a sludge tank 29, a telescopic boom 30, a winch mechanism 31, a fixed boom 32, outrigger cylinders 33, an anti-overwind sensor 34, a sludge grab bucket 35, and a base 36.

[0042] Specifically, the chassis 28 houses a chassis engine and is connected to the base 36. The chassis 28 has a sludge tank 29 and its lower part is connected to the outrigger cylinders 33. The base 36 is internally connected to the rotary motor 10 via a gear assembly and is connected to the bottom of the fixed boom 32. Both external sides of the base 36 are connected to the outrigger cylinders 33. The top of the fixed boom 32 is connected to the telescopic boom 30, and a boom luffing cylinder 13 is located between the fixed boom 32 and the telescopic boom 30. The telescopic boom 30 is equipped with a boom telescopic cylinder 16 and a winch mechanism 31. The winch mechanism 31 is connected to the dredging grab bucket 35 via a wire rope. An anti-overwinding sensor 34 is provided at the end of the telescopic boom 30 near the dredging grab bucket 35 to prevent damage to the wire rope when the winch mechanism 31 is retracting the rope. When the dredging grab bucket 35 touches the anti-overwinding sensor 34 during its ascent, the electrical system automatically shuts off the power. The winch mechanism 31 is internally connected to the winch motor 19. The dredging grab bucket 35 has a grab bucket cylinder 20.

[0043] Another embodiment of the present invention provides a control method for a digging-type pipe dredging vehicle, applied to a digging-type pipe dredging vehicle, comprising the following steps: Step 1: Park the excavator-type pipe dredging vehicle at a suitable distance from the manhole, and control the extension of the outrigger cylinder 33 to prevent the vehicle from tipping over due to uneven load when the dredging grab bucket is grabbing heavy objects. Step 2: Simultaneously operate the boom luffing cylinder 13, slewing motor 10, boom telescopic cylinder 16, and winch motor 19 on the controller to achieve the combined motion of horizontal extension of the telescopic boom 30 and vertical luffing, horizontal rotation of the base 36 driving the rotation of the fixed boom 32, and rope release by the winch mechanism 31 (see the above-mentioned synchronous operation of multiple actuators, in which the electromagnetic proportional directional valve reverses once), until the dredging grab bucket 35 moves to the top of the manhole. Step 3: Move the operating handle of the hoisting motor 19 on the controller to release the rope of the hoisting mechanism 31, so that the dredging grab bucket 35 moves downward until it touches the silt at the bottom of the well. Step 4: Press the operation button on the controller for the dredging grab bucket 35 to open the dredging grab bucket 35; Step 5: Release the operation button of the sludge grab bucket 35 to close the sludge grab bucket 35 and grab the sludge; Step 6: Move the operating handle of the hoisting motor 19 on the controller to make the hoisting mechanism 31 retract the rope, so that the dredging grab bucket 35 moves upward until it leaves the well. Step 7: Simultaneously operate the boom luffing cylinder 13, slewing motor 10, boom telescopic cylinder 16, and winch motor 19 on the controller to realize the horizontal retraction and vertical luffing descent of the telescopic boom 30, the horizontal rotation of the base 36 driving the rotation of the fixed boom 32, and the rope winding of the winch mechanism 31 (see the above-mentioned synchronous operation of multiple actuators, in which the electromagnetic proportional directional valve performs secondary reversing) until the dredging grab bucket 35 moves directly above the sludge tank; Step 8: Press the operation button of the sludge grab bucket 35 on the controller to open the sludge grab bucket 35 and unload the sludge into the sludge tank 29, thus completing a sludge loading and unloading cycle.

[0044] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A hydraulic control system for a digging-type pipe dredging vehicle, characterized in that, include: The outlet of the hydraulic oil tank (1) is connected to the inlet of the gear pump (2), the outlet of the gear pump (2) is connected to the inlet of the proportional multi-way valve (3), the outlet of the proportional multi-way valve (3) is connected to the inlet and outlet of the rotary motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16) and the winch motor (19) respectively, and the return port of the proportional multi-way valve (3) is connected to the inlet of the hydraulic oil tank (1). The proportional multi-way valve (3) includes a three-way flow regulating valve (6), four electromagnetic proportional directional valves, four two-way flow valves, and four shuttle valves. The oil inlet of the proportional multi-way valve (3) is connected to the oil inlet of the three-way flow regulating valve, the two-way flow valve, and the non-spring side end face of the valve core of the three-way flow regulating valve, respectively. The oil outlet of the three-way flow regulating valve is connected to the oil return port of the proportional multi-way valve (3). The oil outlet of the two-way flow valve is connected to the oil inlet of the electromagnetic proportional directional valve and the non-spring side end face of the valve core of the two-way flow valve. The oil outlet of the electromagnetic proportional directional valve is connected to the rotary motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16), and the winding... The inlet and outlet ports of the hoisting motor (19), the first inlet port of the shuttle valve, the valve core spring side end face of the two-way flow valve, the second inlet port of the shuttle valve is connected to the outlet port of another shuttle valve, the outlet port of the shuttle valve is connected to the valve core spring side end face of the three-way flow regulating valve, the valve core spring side end face of the electromagnetic proportional directional valve, the return port of the electromagnetic proportional directional valve is connected to the return port of the proportional multi-way valve (3), when the electromagnetic proportional directional valve is energized, the pressure value of the inlet port of the proportional multi-way valve (3) is equal to the maximum load pressure of the slewing motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16), and the hoisting motor (19) plus a fixed value. The proportional multi-way valve (3) also includes an LS control valve (4) and a damping assembly (5). The outlet of the shuttle valve is connected to the inlet of the damping assembly (5). The outlet of the damping assembly (5) is connected to the inlet of the LS control valve (4) and the valve core spring side end face of the three-way flow regulating valve (6). The outlet of the LS control valve (4) is connected to the valve core spring side end face of the electromagnetic proportional directional valve. When the LS control valve (4) is not energized, its inlet and outlet are open. When the LS control valve (4) is energized, its inlet and outlet are closed.

2. The hydraulic control system of the excavating pipeline dredging vehicle according to claim 1, characterized in that, When the electromagnetic proportional directional valve is not energized, the valve core spring side end face of the two-way flow valve is connected to the oil return port of the proportional multi-way valve (3). When the electromagnetic proportional directional valve is energized, the valve core spring side end face of the two-way flow valve is disconnected from the oil return port of the proportional multi-way valve (3).

3. The hydraulic control system of the excavating pipeline dredging vehicle according to claim 1, characterized in that, The proportional multi-way valve (3) also includes a pressure relief valve (7), the oil inlet of the pressure relief valve (7) is connected to the oil inlet of the proportional multi-way valve (3), and the oil outlet of the pressure relief valve (7) is connected to the oil return port of the proportional multi-way valve (3).

4. The hydraulic control system of the excavating pipeline dredging vehicle according to claim 1, characterized in that, The proportional multi-way valve (3) also includes a filter (8) and a three-way pressure reducing valve (9). The oil inlet of the filter (8) is connected to the oil inlet of the proportional multi-way valve (3), the oil inlet of the three-way pressure reducing valve (9) is connected to the oil outlet of the filter (8), the first oil outlet of the three-way pressure reducing valve (9) is connected to the return oil outlet of the proportional multi-way valve (3), and the second oil outlet of the three-way pressure reducing valve (9) is connected to the valve core spring side end face of the electromagnetic proportional directional valve.

5. The hydraulic control system of the excavating pipeline dredging vehicle according to claim 1, characterized in that, It also includes a grab cylinder (20), the outlet of a proportional multi-way valve (3) is connected to the inlet and outlet of the grab cylinder (20), and the outlet of an electromagnetic proportional directional valve is connected to the inlet and outlet of the grab cylinder (20).

6. The hydraulic control system of the excavating pipeline dredging vehicle according to claim 5, characterized in that, It also includes a selector valve (21), the inlet and outlet of which are connected to the outlet of the proportional multi-way valve (3), and the outlet of the selector valve (21) is connected to the inlet and outlet of the winch motor (19) and the grab cylinder (20) respectively.

7. A digging-type pipe dredging vehicle, comprising a telescopic boom, a winch mechanism, a sludge grab bucket, and a base, characterized in that, The excavating pipe dredging vehicle is equipped with the hydraulic control system of the excavating pipe dredging vehicle as described in any one of claims 1 to 6.

8. A control method for a digging-type pipe dredging vehicle, based on the hydraulic control system of the digging-type pipe dredging vehicle according to any one of claims 1 to 6, characterized in that, include: When the excavating pipeline dredging vehicle stops in front of the manhole, the electromagnetic proportional directional valve is energized and reversed. The hydraulic oil is drawn from the hydraulic oil tank (1) by the gear pump (2) and enters the two-way flow valve and the three-way flow regulating valve (6) through the proportional multi-way valve (3). The hydraulic oil flows out of the two-way flow valve and through the electromagnetic proportional directional valve to the working chamber of the rotary motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16), the winch motor (19) and the first oil inlet of the shuttle valve. The hydraulic oil in the other working chamber of the rotary motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16) and the winch motor (19) flows back to the oil tank through the electromagnetic proportional directional valve and the proportional multi-way valve (3), realizing a compound movement of the base, the telescopic boom and the winch mechanism, and lowering the dredging grab bucket to open and close to grab the silt at the bottom of the manhole. After the sludge is completely grabbed, the electromagnetic proportional directional valve is not switched again. The hydraulic oil is drawn from the hydraulic oil tank (1) by the gear pump (2) and enters the two-way flow valve and the three-way flow regulating valve (6) through the proportional multi-way valve (3). The hydraulic oil flows out of the two-way flow valve and through the electromagnetic proportional directional valve to the other working chamber of the rotary motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16), the winch motor (19) and the first oil inlet of the shuttle valve. The hydraulic oil in one working chamber of the rotary motor (10), the boom luffing cylinder (13), the boom telescopic cylinder (16) and the winch motor (19) flows back to the oil tank through the electromagnetic proportional directional valve and the proportional multi-way valve (3), realizing the secondary compound motion of the base, the telescopic boom and the winch mechanism. The sludge grab bucket is opened and the sludge is unloaded into the sludge tank.

9. The control method for the excavating pipeline dredging vehicle according to claim 8, characterized in that, Also includes: When the excavating pipe dredging vehicle stops in front of the manhole, the outrigger cylinders extend. The first compound motion includes: the horizontal extension of the telescopic boom and the vertical luffing lifting, the horizontal rotation of the base driving the rotation of the fixed boom, and the winch mechanism releasing the rope; the second compound motion includes: the horizontal retraction of the telescopic boom and the vertical luffing descent, the horizontal rotation of the base driving the rotation of the fixed boom, and the winch mechanism retracting the rope.

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