Hydraulic control system of excavator and excavator

Abstract

The invention discloses a hydraulic control system of an excavator and the excavator. The hydraulic control system comprises a hydraulic pump, a supporting leg device, a working device and a controller. The working device comprises a working hydraulic valve group, the supporting leg device comprises a supporting leg frame valve group and a supporting leg claw, and the controller is connected with the control end of the working hydraulic valve group and the control end of the supporting leg frame valve group; the controller outputs a first signal to the working hydraulic valve group, and the bucket is inserted into the ground; a second signal is output to the working hydraulic valve group, and the working device provides upward boosting force along the slope surface; the controller outputs a third signal to a supporting leg frame valve group, and a supporting leg claw is lifted; a fourth signal is output to a supporting leg frame valve group, and a supporting leg claw presses the ground downwards; in a single working cycle of slope climbing, a first signal, a third signal, a second signal and a fourth signal are output in sequence; and after the excavator arrives at the target operation site and the controller outputs a fourth signal, slope-holding excavation operation is carried out. According to the invention, climbing and hill-holding operation of ramps with the gradient of less than 35 degrees can be realized.

Description

Technical Field

[0001] The present invention relates to a hydraulic control system and an excavator of an excavator, belonging to the technical field of construction machinery. Background Art

[0002] During the operation of an excavator on a slope, with the changes in slope and working attitude, the slope holding and climbing ability of the whole machine becomes worse, and dangerous situations such as slope slipping may occur. At present, the maximum climbing slope of an excavator on an actual construction site is generally 25° - 30°, and the stable operation slope is generally about 22°. However, for excavators operating in mountainous areas, due to the constraints of the surface state, the climbing ability of the excavator generally shows a decreasing trend with the change of the landform.

[0003] Currently, for large - slope slopes, methods such as slope reduction and building a zigzag road are generally adopted. The methods of slope reduction and building a zigzag road will cause large land occupation, landform change and vegetation damage. Moreover, during the construction process, the surface soil body is deeply disturbed, making the surface of the equipment passage loose and uneven in hardness. This brings great difficulties and safety risks to subsequent construction. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a hydraulic control system and an excavator of an excavator, which can realize climbing and slope - holding operations on slopes with a slope of less than 35°. To achieve the above - mentioned purpose, the present invention is implemented by the following technical solutions: In a first aspect, the present invention provides a hydraulic control system of an excavator, including: a hydraulic pump, a leg device, a working device and a controller; The working device is arranged on the upper carriage of the excavator and includes a working hydraulic valve group, a boom cylinder, an arm cylinder and a bucket cylinder. The hydraulic pump supplies oil to the boom cylinder, the arm cylinder and the bucket cylinder through the working hydraulic valve group; The leg device is arranged on the lower carriage of the excavator and includes a leg frame valve group, a leg frame cylinder and leg claws. The hydraulic pump supplies oil to the leg frame cylinder through the leg frame valve group; The controller is connected to the control ends of the working hydraulic valve group and the leg frame valve group; When the controller outputs a first signal to the working hydraulic valve group, the bucket cylinder retracts, and the boom cylinder and the arm cylinder extend, and the bucket of the excavator inserts into the ground; when the controller outputs a second signal to the working hydraulic valve group, the boom cylinder and the arm cylinder retract, and the working device of the excavator provides a boosting force upward along the slope; When the controller outputs a third signal to the leg frame valve group, the leg claws are lifted by driving the leg frame cylinder; when the controller outputs a fourth signal to the leg frame valve group, the leg claws are pressed against the ground by driving the leg frame cylinder to reduce the ground contact pressure of the excavator; In a single working cycle of the excavator climbing a steep slope, the controller sequentially outputs a first signal, a third signal, a second signal, and a fourth signal; after the excavator reaches the target working location and the controller outputs the fourth signal, the excavator enters the slope-holding excavation operation.

[0005] In combination with the first aspect, optionally, the outrigger cylinder includes an outrigger rear cylinder for driving the outrigger claw to lift and lower, and an outrigger front cylinder for adjusting the distance between the outrigger claw and the excavator track. The outrigger valve group includes a two-position five-way hydraulic control valve for switching the pressure oil input of the outrigger front cylinder and the rear cylinder, and a main valve standby connection valve provided between the hydraulic pump and the two-position five-way hydraulic control valve. The oil inlet P of the two-position five-way hydraulic control valve is communicated with the oil supply circuit of the hydraulic pump through the main valve standby connection valve, the oil return port T is connected to the fuel tank, the working oil port A1 is communicated with the small chamber of the outrigger front cylinder, the working oil port A2 is communicated with the large chamber of the outrigger front cylinder, the working oil port B1 is communicated with the small chamber of the outrigger rear cylinder, and the working oil port B2 is communicated with the large chamber of the outrigger rear cylinder. The outrigger valve group controls the action of the outrigger rear cylinder or the outrigger front cylinder by switching the valve position of the two-position five-way hydraulic control valve.

[0006] In combination with the first aspect, optionally, the pilot control oil port K of the two-position five-way hydraulic control valve is communicated with the pilot oil circuit of the hydraulic control system through a switch valve. When the switch valve is energized, the pilot oil pressure pushes the spool of the two-position five-way hydraulic control valve to change direction, switching the oil supply direction of the outrigger front cylinder and the outrigger rear cylinder.

[0007] In combination with the first aspect, optionally, the outrigger valve group includes a first proportional valve and a second proportional valve. The oil inlets P of the first proportional valve and the second proportional valve are communicated with the pilot oil circuit of the hydraulic control system, the oil return ports T are connected to the fuel tank, and the working oil ports are respectively connected to the control oil ports of the left and right spools of the main valve standby connection valve. The controller controls the oil supply flow rate and the oil supply direction of the outrigger cylinder by adjusting the current values of the first proportional valve and the second proportional valve.

[0008] In combination with the first aspect, optionally, the outrigger valve group includes a plurality of two-way balance valves for maintaining the pressure in the large and small chambers of the cylinder. The two-way balance valve is provided between the working oil port of the two-position five-way hydraulic control valve and the outrigger front cylinder for locking the inlet and outlet oil circuits of the outrigger front cylinder. The two-way balance valve is provided between the working oil port of the two-position five-way hydraulic control valve and the outrigger rear cylinder for locking the inlet and outlet oil circuits of the outrigger rear cylinder.

[0009] In combination with the first aspect, optionally, the outrigger valve group includes a two-position four-way electromagnetic directional control valve for controlling the extension of the piston rod of the rear cylinder of the outrigger frame; The oil inlet P of the two-position four-way electromagnetic directional control valve is communicated with the oil supply line of the hydraulic pump, the oil return port T is connected to the fuel tank, the working oil port A is connected to the small chamber of the rear cylinder of the outrigger frame, and the working oil port B is communicated with the large chamber of the rear cylinder of the outrigger frame; When the controller outputs an emergency braking signal to the outrigger valve group, the valve position of the two-position five-way hydraulic control valve is switched to the valve position for controlling the action of the front cylinder of the outrigger frame, the two-position four-way electromagnetic directional control valve is turned on, the large chamber of the front cylinder of the outrigger frame is supplied with oil and the small chamber returns oil, the piston rod of the front cylinder of the outrigger frame extends, the large chamber of the rear cylinder of the outrigger frame is supplied with oil and the small chamber returns oil, and the piston rod of the rear cylinder of the outrigger frame extends, and the outrigger claw presses down on the ground to reduce the ground contact pressure of the excavator.

[0010] In combination with the first aspect, optionally, it includes a breaker and a breaker oil circuit for driving the breaker to work, and the breaker oil circuit shares the main valve standby connection valve with the two-position five-way hydraulic control valve; The oil circuit between the oil inlet P of the two-position five-way hydraulic control valve and the main valve standby connection valve includes an oil circuit provided with a stop valve and an oil circuit provided with a manual two-position three-way directional control valve. The two oil circuits are respectively used as the oil inlet passage and the oil drain passage of the two-position five-way hydraulic control valve according to the extension or retraction of the outrigger frame cylinder; The oil inlet P of the manual two-position three-way directional control valve is connected to the main valve standby connection valve, the working oil port A is connected to an oil inlet of the two-position five-way hydraulic control valve, and the working oil port B is connected to the oil inlet of the breaker oil circuit; The manual two-position three-way directional control valve is used to switch the pressure oil input between the outrigger frame cylinder and the breaker by switching the valve position.

[0011] In combination with the first aspect, optionally, it includes a collection component, and the collection component includes a plurality of pressure sensors and a plurality of stroke sensors; The pressure sensors are used to collect the pressures of the large chamber and the small chamber of the boom cylinder, the large chamber and the small chamber of the stick cylinder, and the pressure of the large chamber of the rear cylinder of the outrigger frame; the controller is connected to the pressure sensors to obtain the pressure data of the large chamber and the small chamber of each cylinder in real time; The stroke sensors are used to collect the stroke of the piston rod of the boom cylinder, the stroke of the piston rod of the stick cylinder, the stroke of the piston rod of the front cylinder of the outrigger frame, and the stroke of the piston rod of the rear cylinder of the outrigger frame; the controller is connected to the stroke sensors to obtain the real-time displacement of the piston rod of each cylinder in real time.

[0012] In combination with the first aspect, optionally, a first inverse proportional relief valve and a second inverse proportional relief valve are respectively connected in series on the small chamber oil circuits of the boom cylinder and the stick cylinder; The inlet port of the first inverse proportional overflow valve is communicated with the oil circuit of the small chamber of the boom cylinder, and the oil drain port is connected to the fuel tank; the controller controls the maximum pressure of the small chamber of the boom cylinder by adjusting the current value of the first inverse proportional overflow valve; The inlet port of the second inverse proportional overflow valve is communicated with the oil circuit of the small chamber of the stick cylinder, and the oil drain port is connected to the fuel tank; the controller controls the maximum pressure of the small chamber of the stick cylinder by adjusting the current value of the second inverse proportional overflow valve.

[0013] In a second aspect, the present invention provides an excavator configured with the hydraulic control system of the excavator described in the first aspect.

[0014] Compared with the prior art, the beneficial effects achieved by the hydraulic control system of an excavator and the excavator provided by the embodiments of the present invention include: The present invention includes a hydraulic pump, a leg device, a working device, and a controller; the working device is arranged on the upper vehicle of the excavator and includes a working hydraulic valve group, a boom cylinder, a stick cylinder, and a bucket cylinder. The hydraulic pump supplies oil to the boom cylinder, the stick cylinder, and the bucket cylinder through the working hydraulic valve group; the controller is connected to the control end of the working hydraulic valve group; when the controller outputs a first signal to the working hydraulic valve group, the bucket cylinder retracts, and the boom cylinder and the stick cylinder extend, and the bucket of the excavator inserts into the ground; when the controller outputs a second signal to the working hydraulic valve group, the boom cylinder and the stick cylinder retract, and the working device of the excavator provides a boosting force upward along the slope; through the coordinated retraction action of the boom cylinder and the stick cylinder of the working device, the present invention can provide a boosting force upward along the slope and enhance the active driving force of the excavator on a steep slope; The leg device of the present invention is arranged on the lower vehicle of the excavator and includes a leg frame valve group, a leg frame cylinder, and leg claws. The hydraulic pump supplies oil to the leg frame cylinder through the leg frame valve group; the controller of the present invention is connected to the control end of the leg frame valve group; when the controller outputs a third signal to the leg frame valve group, the leg claws are lifted by driving the leg frame cylinder; when the controller outputs a fourth signal to the leg frame valve group, the leg claws are pressed against the ground by driving the leg frame cylinder to reduce the ground contact pressure of the excavator; the leg device of the present invention drives the leg claws to press against the ground through the fourth signal output by the controller, which can reduce the ground contact pressure of the excavator and avoid ground collapse or structural damage caused by excessive local pressure of the crawler. It is especially suitable for soft, slippery or loose ground surfaces (such as sandy soil and muddy land), and can significantly improve the terrain adaptability; when the leg claws of the present invention press against the ground, the load is dispersed to reduce the damage of the excavator to the surface vegetation and soil structure, and reduce the repair cost of the loosened surface after construction, meeting the environmental protection construction requirements of ecologically sensitive areas; After the excavator reaches the target operation site and the controller outputs the fourth signal, the excavator enters the slope-holding excavation operation; the present invention enables the excavator to achieve stable slope holding on steep slopes with a slope of less than 35°. During the slope-holding operation stage, the outrigger device provides continuous downward pressure to replace the traditional mechanical anchoring, avoiding secondary disturbance to the landform caused by excavation or pile driving. In a single working cycle of the excavator climbing a steep slope, the controller sequentially outputs the first signal, the third signal, the second signal, and the fourth signal; the present invention coordinates the sequential actions of the working device and the outrigger device through the controller, and realizes the coordinated control of the bucket inserting into the ground, the outrigger claws lifting, the working device boosting, and the outrigger claws pressing down in a single working cycle, ensuring seamless connection between the thrust generation and the lifting / pressing actions of the outrigger device, avoiding power interruption, enabling the excavator to safely climb a steep slope with a slope of less than 35°, breaking through the existing climbing limit of 30° - 35°, and greatly expanding the applicable range of the operation scenario; the present invention actively adjusts the ground contact pressure by pressing the outrigger claws against the ground, and combines the auxiliary support of the bucket inserting into the ground, reducing the damage to the surface structure and vegetation caused by the traditional road construction or slope reduction methods, and reducing the risk of surface loosening after construction, meeting the requirements of green construction. Description of the Drawings

[0015] Figure 1 is a hydraulic principle schematic diagram of a hydraulic control system of an excavator in Embodiment 1 of the present invention; Figure 2 is a working process schematic diagram of a hydraulic control system of an excavator in Embodiment 1 of the present invention for climbing a steep slope. Detailed Embodiments

[0016] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be used to limit the protection scope of the present invention.

[0017] Embodiment 1

[0018] This embodiment provides a hydraulic control system for an excavator, which includes a hydraulic pump, an outrigger device, a working device, and a controller.

[0019] The hydraulic pump is used to provide a power oil source for the hydraulic control system of the excavator. A variable displacement piston pump is preferred, which can adjust the output flow according to the load demand. As Figure 1 shown, two hydraulic pumps are configured in this embodiment.

[0020] The working device is arranged on the upper part of the excavator. As Figure 1 shown, it includes a working hydraulic valve group, a boom cylinder, a stick cylinder G1, and a bucket cylinder G2. The hydraulic pump supplies oil to the boom cylinder, the stick cylinder, and the bucket cylinder through the working hydraulic valve group, and controls the telescopic actions of each cylinder through the working hydraulic valve group.

[0021] In this embodiment, as Figure 1 shown, the boom cylinder includes a left boom cylinder G3 and a right boom cylinder G4. The left boom cylinder G3 and the right boom cylinder G4 are completely symmetrical, connected to the same boom, and have exactly the same movement trajectory, and are used to provide sufficient driving force for the boom.

[0022] The outrigger device is arranged on the lower vehicle of the excavator. As Figure 1 shown, it includes an outrigger frame valve group, an outrigger frame cylinder, and outrigger claws. The hydraulic pump supplies oil to the outrigger frame cylinder through the outrigger frame valve group, and the telescopic movement of the outrigger frame cylinder is controlled by the outrigger frame valve group.

[0023] The outrigger frame cylinder includes an outrigger frame rear cylinder and an outrigger frame front cylinder. The outrigger frame rear cylinder is used to drive the outrigger claws to lift and lower. The outrigger frame front cylinder is used to adjust the distance between the outrigger claws and the excavator track.

[0024] In this embodiment, as Figure 1 shown, the outrigger frame front cylinder includes an outrigger frame left front cylinder G8 and an outrigger frame right front cylinder G7, and the outrigger frame rear cylinder includes an outrigger frame left rear cylinder G6 and an outrigger frame right rear cylinder G5.

[0025] The controller is connected to the control ends of the working hydraulic valve group and the outrigger frame valve group. The controller receives the data collected by the acquisition component in real time and outputs a control signal.

[0026] Specifically, the acquisition component includes a plurality of pressure sensors and a plurality of stroke sensors. The controller is connected to the pressure sensors to obtain the pressure data of the large chamber and the small chamber of the cylinder in real time. The controller is connected to the stroke sensors to obtain the real-time displacement of the cylinder piston rod in real time.

[0027] In this embodiment, the pressure sensors include: a pressure sensor F1 for collecting the pressure of the small chamber of the boom cylinder, a pressure sensor F2 for collecting the pressure of the large chamber of the boom cylinder, a pressure sensor F3 for collecting the pressure of the large chamber of the stick cylinder G1, a pressure sensor F4 for collecting the pressure of the small chamber of the stick cylinder G1, a pressure sensor F6 for collecting the pressure of the large chamber of the outrigger frame left rear cylinder G6, and a pressure sensor F5 for collecting the pressure of the large chamber of the outrigger frame right rear cylinder G5.

[0028] It should be noted that the pressure sensor F1 is arranged on the pipeline that simultaneously communicates with the small chambers of the left boom cylinder G3 and the right boom cylinder G4, and the pressure sensor F2 is arranged on the pipeline that simultaneously communicates with the large chambers of the left boom cylinder G3 and the right boom cylinder G4.

[0029] It should be noted that the default back pressure of the small chambers of the outrigger frame left rear cylinder G6 and the outrigger frame right rear cylinder G5 is 0.5 mpa. To save costs, the pressure sensors for collecting the pressure of the small chambers are omitted, and only the pressure sensor F6 and the pressure sensor F5 are set.

[0030] In this embodiment, the stroke sensors include: a stroke sensor for collecting the stroke of the boom cylinder piston rod, a stroke sensor for collecting the stroke of the stick cylinder piston rod, a stroke sensor for collecting the stroke of the left front cylinder G8 of the outrigger frame, a stroke sensor for collecting the stroke of the right front cylinder G7 of the outrigger frame, a stroke sensor for collecting the stroke of the left rear cylinder G6 of the outrigger frame, and a stroke sensor for collecting the stroke of the right rear cylinder G5 of the outrigger frame.

[0031] It should be noted that the movement trajectories of the left boom cylinder G3 and the right boom cylinder G4 are exactly the same, and the stroke of any one of the boom cylinder piston rods is collected.

[0032] As Figure 1 shown, the outrigger frame valve group includes a switching valve V3, a first proportional valve V4, a second proportional valve V5, a two-position four-way solenoid directional valve V6, a two-position five-way hydraulic control valve V7, a two-way balance valve V8, a two-way balance valve V9, a two-way balance valve V10, a two-way balance valve V11, a stop valve V12, a manual two-position three-way directional valve V13, a stop valve V14, a stop valve V15, and a main valve standby connection valve V17.

[0033] The two-position five-way hydraulic control valve V7 is used to switch the pressure oil input of the front and rear cylinders of the outrigger frame. As Figure 1 shown, the oil inlet P of the two-position five-way hydraulic control valve V7 is connected to the oil supply circuit of the hydraulic pump through the main valve standby connection valve V17, the oil return port T is connected to the fuel tank, the working oil port A1 is connected to the small chamber of the front cylinder of the outrigger frame, the working oil port A2 is connected to the large chamber of the front cylinder of the outrigger frame, the working oil port B1 is connected to the small chamber of the rear cylinder of the outrigger frame, and the working oil port B2 is connected to the large chamber of the rear cylinder of the outrigger frame. The outrigger frame valve group controls the action of the rear cylinder or the front cylinder of the outrigger frame by switching the valve position (left valve position or right valve position) of the two-position five-way hydraulic control valve.

[0034] The pilot control oil port K of the two-position five-way hydraulic control valve is connected to the pilot oil circuit of the hydraulic control system through the switching valve V3. When the switching valve V3 is energized, the pilot oil pressure pushes the spool of the two-position five-way hydraulic control valve V7 to change direction, switching the oil supply direction of the front cylinder and the rear cylinder of the outrigger frame.

[0035] In this embodiment, the working oil port A1 is divided into two paths and respectively connected to the small chambers of the left front cylinder G8 and the right front cylinder G7 of the outrigger frame, and the working oil port A2 is divided into two paths and respectively connected to the large chambers of the left front cylinder G8 and the right front cylinder G7 of the outrigger frame. The working oil port B1 is divided into two paths and respectively connected to the small chambers of the left rear cylinder G6 and the right rear cylinder G5 of the outrigger frame, and the working oil port B2 is divided into two paths and respectively connected to the large chambers of the left rear cylinder G6 and the right rear cylinder G5 of the outrigger frame.

[0036] AsFigure 1 As shown, the oil circuit between the oil inlet P of the two-position five-way hydraulic control valve V7 and the standby valve V17 of the main valve includes a first oil circuit provided with a stop valve V12 and a second oil circuit provided with a manual two-position three-way reversing valve V13. The two oil circuits serve as the oil inlet passage and the oil drain passage of the two-position five-way hydraulic control valve V7 respectively according to the extension or retraction of the outrigger cylinder.

[0037] For example, when the first oil circuit serves as the oil inlet passage, the second oil circuit is the oil drain circuit. When the second oil circuit serves as the oil inlet passage, the first oil circuit is the oil drain circuit.

[0038] The two-way balance valves V8, V9, V10, and V11 are used to maintain the pressure in the large and small chambers of the cylinder. The two-way balance valves are provided between the working oil port of the two-position five-way hydraulic control valve and the front outrigger cylinder to lock the inlet and outlet oil circuits of the front outrigger cylinder; the two-way balance valves are provided between the working oil port of the two-position five-way hydraulic control valve and the rear outrigger cylinder to lock the inlet and outlet oil circuits of the rear outrigger cylinder.

[0039] As Figure 1 shown, the two-way balance valve V8 is provided between the left rear outrigger cylinder G6 and the working oil port B of the two-position five-way hydraulic control valve, the two-way balance valve V9 is provided between the right rear outrigger cylinder G5 and the working oil port B of the two-position five-way hydraulic control valve, the two-way balance valve V10 is provided between the left front outrigger cylinder G8 and the working oil port A of the two-position five-way hydraulic control valve, and the two-way balance valve V11 is provided between the right front outrigger cylinder G7 and the working oil port A of the two-position five-way hydraulic control valve.

[0040] For example, after the left front outrigger cylinder G8 and the right front outrigger cylinder G7 of the outrigger extend, the cylinder pressure is maintained through the two-way balance valves V10 and V11 respectively, so that the front outrigger claws maintain the state of extending to the farthest distance.

[0041] As Figure 1 shown, the two-position four-way solenoid reversing valve V6 is used to control the extension of the piston rod of the rear outrigger cylinder. The oil inlet P of the two-position four-way solenoid reversing valve V6 is connected to the oil supply circuit of the hydraulic pump, the oil return port T is connected to the fuel tank, the working oil port A is connected to the small chamber of the rear outrigger cylinder, and the working oil port B is connected to the large chamber of the rear outrigger cylinder.

[0042] In this embodiment, the working oil port A of the two-position four-way solenoid reversing valve V6 is divided into two paths and respectively connected to the small chambers of the left rear outrigger cylinder G6 and the right rear outrigger cylinder G5, and the working oil port B is divided into two paths and respectively connected to the large chambers of the left rear outrigger cylinder G6 and the right rear outrigger cylinder G5.

[0043] As Figure 1As shown in the figure, the main valve standby connection valve V17 is arranged between the hydraulic pump and the two-position five-way hydraulic control valve. The oil inlets P of the first proportional valve V4 and the second proportional valve V5 are connected to the pilot oil circuit of the hydraulic control system, and the oil outlets T are connected to the fuel tank. The working oil port of the first proportional valve V4 is connected to the control oil port of the left spool of the main valve standby connection valve V17, and the working oil port of the second proportional valve V5 is connected to the control oil port of the right spool of the main valve standby connection valve V17. The controller controls the oil supply flow and oil supply direction of the outrigger cylinder by adjusting the current values of the first proportional valve V4 and the second proportional valve V5.

[0044] The first proportional valve V4 and the second proportional valve V5 are energized separately, and the opening degree is adjusted according to the current value output by the controller to control the flow and direction output by V17.

[0045] As Figure 1 shown in the figure, the hydraulic control system of the excavator includes a breaker G9 and a breaker oil circuit for driving the breaker to work. The breaker oil circuit shares the main valve standby connection valve V17 with the two-position five-way hydraulic control valve V7. The pressure oil input of the outrigger cylinder and the breaker is switched by manually switching the valve position of the two-position three-way reversing valve V13.

[0046] Specifically, the oil inlet P of the manually operated two-position three-way reversing valve V13 is connected to the main valve standby connection valve V17, the working oil port A is connected to an oil inlet of the two-position five-way hydraulic control valve V7 (the second oil circuit in this embodiment), and the working oil port B is connected to the oil inlet of the breaker oil circuit.

[0047] A stop valve for cutting off the breaker oil circuit is provided on the breaker oil circuit, including a stop valve Y15 provided on the oil circuit of the breaker oil inlet P and a stop valve Y14 provided on the oil circuit of the breaker oil outlet T. The standby connection of the main valve standby connection valve V17 of the excavator is insufficient, and the breaker working condition and the climbing working condition do not exist at the same time. Therefore, the stop valve is forced to remain closed during climbing operations.

[0048] The working hydraulic valve group includes a first inverse proportional overflow valve V1, a second inverse proportional overflow valve V2, a boom main valve V16, a boom main valve V18, and a bucket main valve V19.

[0049] The boom main valve V16 is used to control the telescopic movement of the boom cylinder G1 according to the output signal of the controller, the boom main valve V18 is used to control the telescopic movement of the boom cylinder according to the output signal of the controller, and the bucket main valve V19 is used to control the telescopic movement of the bucket cylinder G3 according to the output signal of the controller.

[0050] The first inverse proportional overflow valve V1 is connected in series on the small chamber oil circuit of the boom cylinder. The oil inlet of the first inverse proportional overflow valve V1 is connected to the small chamber oil circuit of the boom cylinder, and the oil drain port is connected to the fuel tank. The controller controls the maximum pressure of the small chamber of the boom cylinder by adjusting the current value of the first inverse proportional overflow valve V1.

[0051] The second inverse overflow valve V2 is connected in series to the small chamber oil circuit of the stick cylinder G1. The inlet of the second inverse overflow valve V2 is connected to the small chamber oil circuit of the stick cylinder G1, and the drain port is connected to the fuel tank. The controller controls the maximum pressure of the small chamber of the stick cylinder G1 by adjusting the current value of the second inverse overflow valve V2.

[0052] Based on the hydraulic principle schematic diagram of a hydraulic control system of an excavator as shown in Figure 1 This embodiment also provides the hydraulic control logic of the hydraulic system.

[0053] This embodiment provides an operation process for climbing a steep slope, including: Operation step 1: Preparation actions before climbing.

[0054] It should be noted that before climbing, the driving wheel of the excavator track (the rear wheel of the excavator in this embodiment) faces the top of the slope, and the working device faces away from the top of the slope.

[0055] Operation step 1.1: The controller outputs a first signal to the working hydraulic valve group, the bucket cylinder retracts, the boom cylinder and the stick cylinder extend, and the bucket of the excavator inserts into the ground.

[0056] Specifically, the controller outputs a first signal to the bucket main valve V19, the piston rod of the bucket cylinder G2 retracts to the bottom, and the bucket turns outwards to the bottom. The controller outputs a first signal to the boom main valve V18, and the boom cylinders (left boom cylinder G3 and right boom cylinder G4) extend. The controller outputs a first signal to the stick main valve V16, and the stick cylinder G1 extends. The tip direction of the bucket of the excavator is perpendicular to the slope surface, and the bucket of the excavator inserts into the ground.

[0057] Operation step 1.2: The controller outputs a third signal to the outrigger frame valve group to drive the outrigger claws to lift through the outrigger frame cylinders.

[0058] Specifically, the controller outputs a third signal to the two-position five-way hydraulic control valve V7, the right side passage of the two-position five-way hydraulic control valve V7 is connected, and the piston rods of the rear outrigger frame cylinders (left rear outrigger frame cylinder G6 and right rear outrigger frame cylinder G5) are controlled. The controller outputs a third signal to the switch valve V3 and the first proportional valve V4 to control the piston rods of the rear outrigger frame cylinders (left rear outrigger frame cylinder G6 and right rear outrigger frame cylinder G5) to retract to the set value.

[0059] Before the first climb, the front outrigger frame cylinders need to be extended to make the distance between the outrigger claws and the excavator track the farthest.

[0060] Specifically, the controller outputs a third signal to the two-position five-way hydraulic control valve V7, and the left passage of the two-position five-way hydraulic control valve V7 is connected to control the piston rods of the front cylinders of the outrigger frame (the left front cylinder G8 and the right front cylinder G7 of the outrigger frame). The controller outputs a third signal to the second proportional valve V5 to control the piston rods of the front cylinders of the outrigger frame (the left front cylinder G8 and the right front cylinder G7 of the outrigger frame) to extend to the longest. The controller outputs a third signal to the two-way balance valve V9 and the two-way balance valve V11, and the front cylinders of the outrigger frame (the left front cylinder G8 and the right front cylinder G7 of the outrigger frame) maintain the state where the piston rods extend to the longest.

[0061] It should be noted that in the subsequent steps, the bucket cylinder maintains the state of turning outwards to the frontmost, and the front cylinder of the outrigger frame maintains the state of extending to the longest. The bucket cylinder and the front cylinder of the outrigger frame do not move during the entire climbing process.

[0062] Operation step 2: Climbing action.

[0063] When the controller outputs a second signal to the working hydraulic valve group, the small chambers of the boom cylinder and the stick cylinder are filled with oil, and the piston rods retract, and the working device of the excavator provides a boosting force upward along the slope.

[0064] The controller calculates the retracting speeds of the stick cylinder G1 and the boom cylinder according to the climbing speed of the whole vehicle and the attitude of the whole vehicle, controls the hydraulic pump, the stick main valve V16 and the boom main valve V18 by the pilot valve group, and distributes the flow rate proportionally to the small chambers of the boom cylinder and the stick cylinder G1. Then, through the stroke sensors of the left boom cylinder G3 and the stick cylinder G1, the actual retracting speed of the cylinder is fed back to the controller to achieve closed-loop regulation. The boosting force should be at a suitable value to improve the ground contact pressure of the whole vehicle and enhance the climbing ability.

[0065] Specifically, according to the climbing speed of the whole vehicle and the attitude of the whole vehicle, the upper limit of the pressure values of the small chambers of the stick cylinder G1 and the boom cylinder is calculated. The controller sends signals to the electromagnets of the first inverse proportional overflow valve V1 and the second inverse proportional overflow valve V2 to adjust the upper limit of the pressure of the first inverse proportional overflow valve V1 and the second inverse proportional overflow valve V2, thereby controlling the boosting force of the working device.

[0066] In this embodiment, through the coordinated retracting actions of the boom cylinder and the stick cylinder of the working device, a boosting force upward along the slope can be provided, enhancing the active driving force of the excavator on a steep slope.

[0067] Operation step 3: The first climbing action ends, and there is a short stay on the slope.

[0068] Operation step 3.1: The controller outputs a fourth signal to the outrigger frame valve group, and drives the outrigger claws to press down on the ground through the outrigger cylinders to reduce the ground contact pressure of the excavator.

[0069] Specifically, the controller outputs a fourth signal to the switching valve V3, causing its electromagnet Y3 to be energized. The switching valve V3 changes its position, and the pilot oil port K of the two-position five-way hydraulic control valve V7 is supplied with oil, driving the two-position five-way hydraulic control valve V7 to act. The right-side passage of the two-position five-way hydraulic control valve V7 is connected, controlling the piston rods of the rear cylinders of the outrigger frame (the left rear cylinder G6 and the right rear cylinder G5 of the outrigger frame). The controller outputs a fourth signal to the first proportional valve V4 and the second proportional valve V5. The large chambers of the rear cylinders of the outrigger frame (the left rear cylinder G6 and the right rear cylinder G5 of the outrigger frame) are supplied with oil, and the small chambers return oil, causing the piston rods to extend, driving the outrigger claws to press down on the ground, reducing the ground contact pressure of the excavator and increasing the stability of the excavator.

[0070] Operation step 4: Prepare for the next uphill climb.

[0071] Operation step 4.1: The controller outputs a first signal to the working hydraulic valve group. The bucket cylinder retracts (maintains), the boom cylinder and the stick cylinder extend. The bucket retracts and approaches the cab, with the bucket tip direction perpendicular to the slope surface, and the bucket of the excavator inserts into the ground.

[0072] Operation step 4.2: The controller outputs a third signal to the outrigger frame valve group, driving the outrigger claws to lift through the outrigger frame cylinders.

[0073] Specifically, the controller outputs a third signal to the switching valve V3, causing its electromagnet Y3 to be energized. The switching valve V3 changes its position, and the pilot oil port K of the two-position five-way hydraulic control valve V7 is supplied with oil, driving the two-position five-way hydraulic control valve V7 to act. The right-side passage of the two-position five-way hydraulic control valve V7 is connected, controlling the piston rods of the rear cylinders of the outrigger frame (the left rear cylinder G6 and the right rear cylinder G5 of the outrigger frame). The controller outputs a third signal to the first proportional valve V4 and the second proportional valve V5. The small chambers of the rear cylinders of the outrigger frame (the left rear cylinder G6 and the right rear cylinder G5 of the outrigger frame) are supplied with oil, and the large chambers return oil, causing the piston rods to retract, driving the outrigger claws to lift, and completing the preparation for the next uphill climb.

[0074] In a single working cycle of the excavator climbing a steep slope, the controller sequentially outputs the first signal, the third signal, the second signal, and the fourth signal (operation step 1 → operation step 2 → operation step 3). After completing one working cycle, the controller sequentially outputs the first signal, the third signal, the second signal, and the fourth signal (operation step 4 → operation step 2 → operation step 3).

[0075] In this embodiment, the ground contact pressure is actively adjusted by pressing the outrigger claws on the ground, and combined with the auxiliary support of inserting the bucket into the ground, it reduces the damage to the surface structure and vegetation in the traditional road construction or slope reduction methods, and reduces the risk of surface loosening after construction, meeting the requirements of green construction.

[0076] In this embodiment, after the excavator reaches the target working location and the controller outputs a fourth signal, the excavator enters the slope parking excavation operation.

[0077] During the slope parking excavation operation, the outrigger device presses down on the ground to reduce the ground contact pressure of the excavator and increase the stability of the excavator, and the working device performs the operation.

[0078] This embodiment enables the excavator to achieve stable slope parking on steep slopes with a slope of less than 35°. During the slope parking operation stage, a continuous downward pressure is provided by the outrigger device to replace the traditional mechanical anchoring, avoiding secondary disturbance to the landform caused by excavation or piling.

[0079] As Figure 2 shown, this embodiment provides an operation process for emergencies occurring during the steep slope climbing operation, including: The excavator operator presses the emergency brake button in the cab, and the controller outputs an emergency brake signal to the outrigger valve group. The valve position of the five-port two-position hydraulic control valve V7 is switched to the valve position for controlling the action of the front outrigger cylinder. The four-port two-position electromagnetic reversing valve V6 is turned on. The large chamber of the front outrigger cylinder is filled with oil and the small chamber returns oil. The piston rod of the front outrigger cylinder extends. The large chamber of the rear outrigger cylinder is filled with oil and the small chamber returns oil. The piston rod of the rear outrigger cylinder extends, and the outrigger claw presses down on the ground to reduce the ground contact pressure of the excavator.

[0080] Specifically, the controller outputs an emergency brake signal to the five-port two-position hydraulic control valve V7, and the left passage of the five-port two-position hydraulic control valve V7 is connected to control the piston rod of the front outrigger cylinder (the left front outrigger cylinder G8 and the right front outrigger cylinder G7) of the outrigger. The controller outputs an emergency brake signal to the first proportional valve V4 and the second proportional valve V5, and the proportional electromagnets Y4 and Y5 are energized. The large chamber of the front outrigger cylinder (the left front outrigger cylinder G8 and the right front outrigger cylinder G7) is filled with oil and the small chamber returns oil, and the piston rod extends. The controller outputs an emergency brake signal to the four-port two-position electromagnetic reversing valve V6, and the electromagnet Y6 is energized and the valve opens. The large chamber of the rear outrigger cylinder (the left rear outrigger cylinder G6 and the right rear outrigger cylinder G5) is filled with oil and the small chamber returns oil, and the piston rod extends to drive the outrigger claw to press down on the ground, reducing the ground contact pressure of the excavator and increasing the stability of the excavator.

[0081] In this embodiment, by pressing down the ground with the outrigger claws of the outrigger device, the ground contact pressure of the excavator can be reduced, avoiding ground collapse or structural damage caused by excessive local pressure of the crawler. It is especially suitable for soft, slippery or loose surfaces (such as sandy soil, muddy land), and can significantly improve the terrain adaptability. When the outrigger claws press down on the ground, the damage to the surface vegetation and soil structure of the excavator is reduced by dispersing the load, and the repair cost of the loosened surface after construction is reduced, meeting the environmental protection construction requirements of ecologically sensitive areas.

[0082] In this embodiment, the controller coordinates the timing actions of the working device and the outrigger device, and realizes the coordinated control of the bucket inserting into the ground, the outrigger claws lifting, the working device boosting, and the outrigger claws pressing down in a single working cycle, ensuring seamless connection between the thrust generation and the lifting / pressing actions of the outrigger device, avoiding power interruption, enabling the excavator to safely climb slopes with a slope of less than 35°, breaking through the existing climbing limit of 30° - 35°, and greatly expanding the applicable range of the operation scenario.

[0083] Embodiment 2

[0084] This embodiment provides an excavator configured with the hydraulic control system of the excavator provided in Embodiment 1.

[0085] As a further improvement, a first inclination sensor is installed on the upper carriage of the excavator, a rotary encoder is installed in the middle return, and a second inclination sensor is installed on the lower carriage.

[0086] The controller in the hydraulic control system of the excavator provided in Embodiment 1 is connected to the first inclination sensor, the rotary encoder, and the second inclination sensor, and the controller obtains the real-time attitude of the excavator according to the obtained inclination data and rotary angle.

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

Claims

1. A hydraulic control system for an excavator, characterized in that, It includes a hydraulic pump, outrigger device, working device and controller; The working device is arranged on the upper part of the excavator and includes a working hydraulic valve group, boom cylinder, arm cylinder and bucket cylinder. The hydraulic pump supplies oil to the boom cylinder, arm cylinder and bucket cylinder through the working hydraulic valve group; The outrigger device is arranged on the lower part of the excavator and includes an outrigger frame valve group, outrigger frame cylinder and outrigger claw. The hydraulic pump supplies oil to the outrigger frame cylinder through the outrigger frame valve group; The controller is connected to the control ends of the working hydraulic valve group and the outrigger frame valve group; When the controller outputs a first signal to the working hydraulic valve group, the bucket cylinder retracts, and the boom cylinder and arm cylinder extend, and the bucket of the excavator inserts into the ground; when the controller outputs a second signal to the working hydraulic valve group, the boom cylinder and arm cylinder retract, and the working device of the excavator provides a boosting force upward along the slope; When the controller outputs a third signal to the outrigger frame valve group, the outrigger claw is lifted by driving the outrigger frame cylinder; when the controller outputs a fourth signal to the outrigger frame valve group, the outrigger claw is pressed against the ground by driving the outrigger frame cylinder to reduce the ground contact pressure of the excavator; In a single working cycle of the excavator climbing a steep slope, the controller sequentially outputs a first signal, a third signal, a second signal, and a fourth signal; after the excavator reaches the target operation location and the controller outputs a fourth signal, the excavator enters the slope parking excavation operation.

2. The hydraulic control system of the excavator according to claim 1, wherein The outrigger frame cylinder includes an outrigger frame rear cylinder for driving the outrigger claw to lift and press down and an outrigger frame front cylinder for adjusting the distance between the outrigger claw and the excavator track; The outrigger frame valve group includes a two-position five-way hydraulic control valve for switching the pressure oil input of the outrigger frame front cylinder and rear cylinder and a main valve standby connection valve arranged between the hydraulic pump and the two-position five-way hydraulic control valve; The oil inlet P of the two-position five-way hydraulic control valve is communicated with the oil supply circuit of the hydraulic pump through the main valve standby connection valve, the oil return port T is connected to the fuel tank, the working oil port A1 is communicated with the small chamber of the outrigger frame front cylinder, the working oil port A2 is communicated with the large chamber of the outrigger frame front cylinder, the working oil port B1 is communicated with the small chamber of the outrigger frame rear cylinder, and the working oil port B2 is communicated with the large chamber of the outrigger frame rear cylinder; The outrigger frame valve group controls the action of the outrigger frame rear cylinder or the outrigger frame front cylinder by switching the valve position of the two-position five-way hydraulic control valve.

3. The hydraulic control system of the excavator according to claim 2, characterized in that, The pilot control oil port K of the two-position five-way hydraulic control valve is communicated with the pilot oil circuit of the hydraulic control system through a switching valve. When the switching valve is energized, the pilot oil pressure pushes the spool of the two-position five-way hydraulic control valve to commutate, switching the oil supply direction of the outrigger frame front cylinder and the outrigger frame rear cylinder.

4. The hydraulic control system of the excavator according to claim 2, characterized in that, The outrigger frame valve group includes a first proportional valve and a second proportional valve; The oil inlets P of the first proportional valve and the second proportional valve are communicated with the pilot oil circuit of the hydraulic control system, the oil return ports T are connected to the fuel tank, and the working oil ports are respectively connected to the control oil ports of the left and right spools of the main valve standby connection valve. The controller controls the oil supply flow rate and oil supply direction of the outrigger frame cylinder by adjusting the current values of the first proportional valve and the second proportional valve.

5. The hydraulic control system of an excavator according to claim 2, characterized in that, The outrigger frame valve group includes a plurality of two-way balance valves for maintaining the pressure in the large and small chambers of the cylinder; The two-way balance valve is arranged between the working oil port of the two-position five-way hydraulic control valve and the front cylinder of the outrigger frame, and is used to lock the inlet and outlet oil circuits of the front cylinder of the outrigger frame; The two-way balance valve is arranged between the working oil port of the two-position five-way hydraulic control valve and the rear cylinder of the outrigger frame, and is used to lock the inlet and outlet oil circuits of the rear cylinder of the outrigger frame.

6. The hydraulic control system of the excavator according to claim 2, characterized in that, The outrigger frame valve group includes a two-position four-way electromagnetic directional valve for controlling the piston rod of the rear cylinder of the outrigger frame to extend; The oil inlet P of the two-position four-way electromagnetic directional valve is communicated with the oil supply circuit of the hydraulic pump, the oil return port T is connected to the oil tank, the working oil port A is connected to the small chamber of the rear cylinder of the outrigger frame, and the working oil port B is communicated with the large chamber of the rear cylinder of the outrigger frame; When the controller outputs an emergency braking signal to the outrigger frame valve group, the valve position of the two-position five-way hydraulic control valve is switched to the valve position for controlling the action of the front cylinder of the outrigger frame, the two-position four-way electromagnetic directional valve is turned on, the large chamber of the front cylinder of the outrigger frame is filled with oil, the small chamber returns oil, the piston rod of the front cylinder of the outrigger frame extends, the large chamber of the rear cylinder of the outrigger frame is filled with oil, the small chamber returns oil, the piston rod of the rear cylinder of the outrigger frame extends, and the outrigger foot presses down on the ground to reduce the ground contact pressure of the excavator.

7. The hydraulic control system of the excavator according to claim 2, wherein It includes a breaker and a breaker oil circuit for driving the breaker to work, and the breaker oil circuit shares the main valve standby joint valve with the two-position five-way hydraulic control valve; The oil circuit between the oil inlet P of the two-position five-way hydraulic control valve and the main valve standby joint valve includes an oil circuit provided with a stop valve and an oil circuit provided with a manual two-position three-way directional valve. The two oil circuits are respectively used as the oil inlet passage and the oil drain passage of the two-position five-way hydraulic control valve according to the extension or retraction of the outrigger frame cylinder; The oil inlet P of the manual two-position three-way directional valve is connected to the main valve standby joint valve, the working oil port A is connected to an oil inlet of the two-position five-way hydraulic control valve, and the working oil port B is connected to the oil inlet of the breaker oil circuit; The manual two-position three-way directional valve is used to switch the pressure oil input of the outrigger frame cylinder and the breaker by switching the valve position.

8. The hydraulic control system of the excavator according to claim 2, characterized in that, It includes a collection component, and the collection component includes a plurality of pressure sensors and a plurality of stroke sensors; The pressure sensors are used to collect the pressures of the large chamber and the small chamber of the boom cylinder, the large chamber and the small chamber of the stick cylinder, and the large chamber of the rear cylinder of the outrigger frame; the controller is connected to the pressure sensors to obtain the pressure data of the large chamber and the small chamber of each cylinder in real time; The stroke sensors are used to collect the strokes of the piston rods of the boom cylinder, the stick cylinder, the front cylinder of the outrigger frame, and the rear cylinder of the outrigger frame; the controller is connected to the stroke sensors to obtain the real-time displacement of the piston rods of each cylinder in real time.

9. The hydraulic control system of the excavator according to claim 1, wherein, First inverse proportional overflow valves and second inverse proportional overflow valves are respectively connected in series on the small chamber oil circuits of the boom cylinder and the stick cylinder; The oil inlet of the first inverse proportional overflow valve is communicated with the small chamber oil circuit of the boom cylinder, and the oil drain port is connected to the oil tank; the controller controls the maximum pressure of the small chamber of the boom cylinder by adjusting the current value of the first inverse proportional overflow valve; The oil inlet of the second inverse proportional overflow valve is communicated with the small chamber oil circuit of the stick cylinder, and the oil drain port is connected to the oil tank; the controller controls the maximum pressure of the small chamber of the stick cylinder by adjusting the current value of the second inverse proportional overflow valve.

10. An excavator, characterized in that, It is configured with the hydraulic control system of the excavator according to any one of claims 1-9.

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