Operation mode switching control system and excavator

Abstract

The invention relates to an excavator, in particular to an operation mode switching control system and an excavator, and the system comprises a hydraulically-controlled mode switching valve, a mode control valve, a control unit and a mode setting device. The mode control valve is provided with a control oil port connected with the hydraulic control end of the mode switching valve, an oil inlet connected with a pilot oil source and an oil return port connected with an oil return path, the oil inlet is communicated with the control oil port when the mode control valve is located at the left position, the oil port is controlled to be cut off when the mode control valve is located at the middle position, and the oil port is controlled to be communicated with the oil return port when the mode control valve is located at the right position; the control unit is electrically connected with the mode control valve and used for controlling the mode control valve to be intermittently switched between the left position and the middle position in the second working mode. In the invention, the mode switching valve can work in the second operation mode when the mode control valve is intermittently electrified, and the mode control valve is intermittently electrified, so that the heating of the mode switching valve is reduced, and the service life of the mode switching valve is prolonged.

Description

Technical Field

[0001] The present invention relates to an excavator, and more particularly to an operation mode switching control system and an excavator. Background Art

[0002] Construction machinery such as excavators usually include actions such as boom lifting, arm retraction, bucket retraction, left and right rotation, or similar actions. For excavators, the boom, arm, bucket, and rotation actions are all completed through two handles. Generally, the front, back, left, and right directions of the left-hand handle of the excavator respectively control the arm swing outward, arm retraction, left rotation of the upper part of the whole machine, and right rotation of the upper part of the whole machine; the front, back, left, and right directions of the right-hand handle respectively control the boom lowering, boom raising, bucket retraction, and bucket swing outward. Due to different manufacturers, the operation modes of some complete machines of each manufacturer are slightly different, resulting in different operation modes that excavator operators are familiar with and good at. For different excavator working conditions, choosing the appropriate operation mode can also effectively improve work efficiency, so it is particularly important to switch the operation mode of the whole machine conveniently and quickly.

[0003] The current mainstream solution is to use a mechanical switching valve to complete the action switching by controlling the direction of the pilot control oil, thereby realizing different operating modes. Compared with the method of switching by reconnecting the handle hydraulic pipeline, this switching method not only improves the switching efficiency of the operating mode, but also effectively avoids the leakage of hydraulic oil and pollution of the environment during the removal of the pipeline, and reduces the probability of the hydraulic system being contaminated by foreign matter and causing the whole machine to fail. Since the switching valve is usually installed outside the cab, each time the operating mode is switched, the operator needs to get off the vehicle and use tools to complete the switch. In addition, due to the different layouts of different machines, the position of the switching valve is also different, which reduces the efficiency of the operating mode switching. With the continuous improvement of the automation requirements of excavators, mechanical switching valves no longer meet the use requirements.

[0004] The latest control method is to use electromagnetic switching valve to realize the operation mode switching control. The operator can complete the action switching directly in the cab, and the mode status can be displayed on the instrument. The control principle is that when the operator turns the switch button, the electromagnet on one side of the electromagnetic switching valve is energized, the valve core is reversed, the oil circuit is switched, and the mode is quickly switched. The electromagnetic switching valve is a two-position valve. One of the working positions is maintained by the spring when the electromagnetic iron is powered off, and the other working position requires the electromagnetic iron to be powered on to overcome the spring elastic force to maintain. To maintain the switched mode, the electromagnetic coil needs to be energized all the time, which is easy to make the coil heat up, increase the current loss, and affect the service life of the electromagnetic valve. Every time the whole machine is shut down, the operation mode will default to the initial state due to the power failure of the electromagnetic valve. If the electrical function fails after the whole machine is restarted, and the operator is used to the switched mode, the whole machine may have safety risks. Moreover, if the electrical control of the electromagnetic valve fails, the electromagnetic switching valve cannot be switched, which affects the work efficiency of the operator. Summary of the invention

[0005] The technical problem to be solved by the present invention is the disadvantages of switching of electromagnetic switching valves in the existing operation mode switching control system, and an operation mode switching control system and an excavator are provided.

[0006] The technical solution for achieving the purpose of the present invention is: an operation mode switching control system, comprising a mode switching valve arranged on a pilot control oil circuit for switching between a first operation mode and a second operation mode, a mode control valve, a control unit, and a mode setting device;

[0007] The mode switching valve is a hydraulically controlled valve;

[0008] The mode control valve has a control end electrically connected to the control unit and has a control oil port connected to the hydraulic control end of the mode switching valve, an oil inlet connected to the pilot oil source, and an oil return port connected to the oil return oil circuit, and the oil inlet is connected to the control oil port when in the left position, the control oil port is cut off when in the middle position, and the control oil port is connected to the oil return port when in the right position;

[0009] The mode setting device is electrically connected to the control unit and is used to input a first operation mode working instruction and a second operation mode working instruction;

[0010] The control unit is used for controlling the mode control valve to intermittently switch between the left position and the middle position in the second working mode.

[0011] In the operating mode switching control system of the present invention, the control unit is configured to control the mode control valve to operate in the middle position in the first operating mode, and when the mode setting device outputs a working instruction to switch from the second operating mode to the first operating mode, it controls the mode control valve to switch to the right position and then to the middle position.

[0012] In the operation mode switching control system of the present invention, the hydraulic control end of the mode switching valve is connected to an accumulator.

[0013] In the operation mode switching control system of the present invention, the mode switching valve has a manual switching lever for manual switching and reversing.

[0014] In the operation mode switching control system of the present invention, the mode setting device is configured as a vehicle-mounted instrument capable of displaying the current operation mode.

[0015] In the operating mode switching control system of the present invention, the control unit includes a timing module, and the control unit is configured to periodically control the mode control valve to switch between the left position and the middle position in the second operating mode.

[0016] In the operation mode switching control system of the present invention, the system also includes a pressure detection device for detecting the pressure at the hydraulic control end of the mode switching valve and electrically connected to the control unit, and the control unit is configured to control the mode control valve to operate in the left position in the second operation mode and when the pressure at the hydraulic control end of the mode switching valve is less than a preset value; or the system also includes a valve stem position sensor for detecting the valve stem position of the mode switching valve, and the control unit is configured to control the mode control valve to operate in the left position in the second operation mode and when the valve stem of the mode switching valve is reset to a predetermined position.

[0017] In the operation mode switching control system of the present invention, the mode control valve is a three-position three-way solenoid valve. Alternatively, the mode control valve includes a three-position four-way solenoid valve and a hydraulically controlled one-way valve; the first oil port of the three-position four-way solenoid valve is an oil inlet, the second oil port is an oil return port, the third oil port is connected to the forward conducting oil inlet end of the hydraulically controlled one-way valve, and the fourth oil port is connected to the hydraulic control end of the hydraulically controlled one-way valve; the oil outlet end of the hydraulically controlled one-way valve is a control oil port; when the three-position four-way solenoid valve is in the left position, the first oil port is connected to the third oil port, when it is in the middle position, the first oil port is cut off, and when it is in the right position, the first oil port is connected to the fourth oil port and the second oil port is connected to the third oil port.

[0018] Compared with the prior art, in the present invention, the mode switching valve adopts a hydraulically controlled valve, which is controlled by the mode control valve. In the second working mode, the mode control valve intermittently switches between the left position and the middle position, so that the pressure of the hydraulically controlled end of the mode switching valve is maintained in a certain range and the mode switching valve works in the second operating mode. The mode control valve is intermittently energized to reduce its heat generation and extend its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the operating mode switching control system of the present invention.

[0020] Figure 2It is another control principle diagram of the mode switching valve in the operating mode switching control system of the present invention.

[0021] Parts names and serial numbers in the figure:

[0022] A first pilot valve 10, a second pilot valve 11, a pilot control oil circuit 12, a mode switching valve 21, a mode control valve 22, a manual switching lever 23, a pressure detection device 24, a three-position four-way solenoid valve 221, a hydraulically controlled one-way valve 222, a first control main valve 30, a second control main valve 30, a control unit 40, and a mode setting device 50. DETAILED DESCRIPTION

[0023] The specific implementation scheme is described below with reference to the accompanying drawings.

[0024] Embodiment 1.

[0025] The operation mode switching control system includes a mode switching valve 21 disposed on the pilot control oil circuit 12 for switching between a first operation mode and a second operation mode, a mode control valve 22 , a control unit 40 , and a mode setting device 50 .

[0026] The mode control valve 22 is used to control the mode switching valve 21 to work in the left position or the right position. The control unit 40 is used to control the mode control valve 22 to work in the left position, the middle position or the right position.

[0027] like Figure 1 As shown, the mode switching valve 21 is a hydraulically controlled valve. The mode control valve 22 has a control oil port (D port) connected to the hydraulically controlled end of the mode switching valve 21, an oil inlet port (P port) connected to the pilot oil source, and an oil return port (T port) connected to the oil return oil circuit, and the oil inlet port (P port) is connected to the control oil port (D port) when in the left position, the control oil port (D port) is cut off when in the middle position, and the control oil port (D port) is connected to the oil return port (T port) when in the right position.

[0028] The mode setting device 50 is electrically connected to the control unit 40 and is used to input the first operation mode working instruction and the second operation mode working instruction.

[0029] When receiving the first operation mode working instruction or the second operation mode working instruction, the control unit 40 outputs a control current to the mode control valve 22 to make the operation mode switching control system operate in the first operation mode or the second operation mode.

[0030] The control unit 40 is electrically connected to the electric control end of the mode control valve 22 and is used to control the mode control valve 22 to intermittently switch between the left position and the middle position in the second working mode.

[0031] like Figure 1As shown, the mode switching valve 21 is arranged on the pilot control oil circuit 12, and there are two groups of pilot valves in the pilot control oil circuit 12, namely the first pilot valve 10 and the second pilot valve 11. The two groups of pilot valves are used to control two control main valves, namely the first control main valve 30 and the second control main valve 31.

[0032] The mode switching valve 21 is a two-position valve. When the force of the hydraulic oil at its hydraulic control end acting on the valve stem is less than the elastic force of the spring chamber, it is in the left position, its A1 port is connected to the P1 port, the B1 port is connected to the T1 port, the A2 port is connected to the P2 port, and the B2 port is connected to the T2 port. At this time, the first pilot valve 10 controls the first control main valve 30, and the second pilot valve 11 controls the second control main valve 31. This is the first operation mode. When the hydraulic control end of the mode switching valve 21 is filled with a certain pressure of pilot pressure oil, the force of the hydraulic oil at the hydraulic control end acting on the valve stem is greater than the elastic force of the spring chamber, the mode switching valve 21 is in the right position, its A1 port is connected to the T1 port, the B1 port is connected to the P1 port, the A2 port is connected to the T2 port, and the B2 port is connected to the P2 port. At this time, the first pilot valve 10 controls the second control main valve 31, and the second pilot valve 11 controls the first control main valve 30. This is the second operation mode. By controlling the working position of the mode switching valve 21 , the switching between the first operation mode and the second operation mode can be achieved.

[0033] The mode control valve 22 is a three-position three-way solenoid valve, whose control oil port (D port) is connected to the hydraulic control end of the mode switching valve 21, the oil inlet (P port) is connected to the pilot oil source, and the oil return port (T port) is connected to the oil return oil circuit. The pilot oil source provides pilot pressure oil for the pilot control of the hydraulic system, which can be provided by the pilot pump or by reducing the pressure of the working main oil circuit connected to the main pump port of the hydraulic system through the pilot oil supply valve. The oil return oil circuit is connected to the hydraulic oil tank.

[0034] When the mode control valve 22 is in the left position, the oil inlet (P port) and the control oil port (D port) are connected, and the pilot pressure oil provided by the pilot oil source enters the hydraulic control end of the mode switching valve 21 through the oil inlet (P port) and the control oil port (D port) of the mode control valve 22, pushing the valve stem of the mode switching valve 21 to move to the left, so that the mode switching valve 21 works in the right position.

[0035] When the mode control valve 22 is in the middle position, the control oil port (D port) is cut off. Since the control oil port (D port) is cut off, the pilot oil at the hydraulic end of the mode switching valve 21 is blocked and cannot flow back to the hydraulic oil tank. Therefore, when the mode control valve 22 is switched from the left position to the middle position, the valve stem of the mode switching valve 21 cannot be reset from the left position to the right position because the oil at the hydraulic end cannot flow back to the hydraulic oil tank, so the mode switching valve 21 still works in the left position.

[0036] When the mode control valve 22 is in the right position, the control oil port (D port) and the return oil port (T port) are connected, and the hydraulic control end of the mode switching valve 21 is connected to the return oil circuit through the control oil port (D port) and the return oil port (T port) of the mode control valve 22. The valve stem of the mode switching valve 21 is reset under the action of the spring force of its spring chamber, and the mode switching valve 21 works in the right position, and it switches from the second operating mode to the first working mode.

[0037] The mode setting device 50 is electrically connected to the control unit 40, and is used to input the first operation mode working instruction and the second operation mode working instruction so as to make the mode switching valve 21 work in the first operation mode or the second operation mode. The control unit 40 can be a controller, such as a whole machine controller of an excavator. The mode setting device 50 can be an on-board instrument of a machine equipment, through which the operation mode can be set, and the current operation mode can be displayed.

[0038] In this embodiment, when the operator sets the operation mode of the machine to the second operation mode (the first operation mode before setting) through the mode setting device 50, the control unit 40 controls the mode control valve 22 to work in the left position, the mode switching valve 21 switches to the right position, and the mode switching valve 21 works in the second operation mode. Then the control unit 40 controls the mode control valve 22 to work in the middle position, the oil at the hydraulic control end of the mode switching valve 21 does not flow out, and the mode switching valve 21 continues to work in the left position, maintaining the second operation mode.

[0039] When the mode control valve 22 is in the middle position, the oil return channel of the hydraulic control end of the mode switching valve 21 is cut off by the mode control valve 22. Under the extrusion of the valve stem pushed by the spring in the spring chamber, the hydraulic pressure of the hydraulic control end of the mode switching valve 21 is higher than the normal pressure (the pressure of the hydraulic oil tank). Since the mode control valve 22 and the mode switching valve 21 are both slide valves, leakage is inevitable. The oil at the hydraulic control end of the mode switching valve 21 also leaks under the extrusion of the valve stem. Therefore, the mode control valve 22 is in the middle position, and the mode switching valve 21 is reset to the left position at a slow speed. In order to prevent the mode switching valve 21 from automatically resetting to the first operating mode in the second operating mode, the control unit 40 controls the mode control valve 22 to switch intermittently between the left position and the middle position in the second working mode, that is, to intermittently fill the hydraulic control end of the mode switching valve 21 with liquid, so that the mode switching valve 21 always works in the right position. The length of the interval time for the mode control valve 22 to switch between the left position and the middle position depends on the speed of the oil leakage from the hydraulic control end of the mode switching valve 21. If the oil leakage is negligible, then in the second operating mode, the interval for the mode control valve 22 to switch from the middle position to the left position will be longer; if the oil leakage is more obvious, then in the second operating mode, the interval for the mode control valve 22 to switch from the middle position to the left position will be shorter, and even periodic frequent switching may be required.

[0040] When the operator sets the operation mode of the machine to the first operation mode (the second operation mode before setting) through the mode setting device 50, the control unit 40 controls the mode control valve 22 to work in the right position, and the hydraulic control end of the mode switching valve 21 is connected to the return oil circuit through the control oil port (D port) and the return oil port (T port) of the mode control valve 22. The mode switching valve 21 is reset to the left position under the action of the spring force of its spring chamber, and the mode switching valve 21 is also switched from the second operation mode to the first operation mode. After the mode switching valve 21 is switched to the left position, the mode control valve 22 is powered off and resets to the middle position by itself. When the mode control valve 22 is reset to the middle position, the mode switching valve 21 remains in the left position.

[0041] Optionally, an accumulator (not shown) is connected to the hydraulic control end of the mode switching valve 21. When the mode switching valve 21 switches from the right position to the left position, the volume change of its hydraulic control end is small. If the hydraulic control end of the mode switching valve 21 leaks oil outward at a fast speed, the time it takes for the mode switching valve 21 to reset from the right position to the left position is short. When the hydraulic control end of the mode switching valve 21 is connected to the accumulator, when the hydraulic control end of the mode switching valve 21 leaks oil outward, the accumulator can release supplementary oil to the hydraulic control end of the mode switching valve 21, thereby extending the time it takes for the mode switching valve 21 to switch from the right position to the left position.

[0042] Optionally, the operation mode switching control system may also be provided with a pressure detection device 24 electrically connected to the control unit 40, and the pressure detection device 24 is used to detect the pressure at the hydraulic control end of the mode switching valve 21. As the oil at the hydraulic control end of the mode switching valve 21 leaks, the spring in the spring chamber of the mode switching valve 21 is released due to the movement of the valve stem, and the pressure at the hydraulic control end of the mode switching valve 21 also decreases accordingly. By detecting the pressure at the hydraulic control end of the mode switching valve 21 by the pressure detection device 23, the reset degree of the mode switching valve 21 in the second operation mode can be determined. In the second operation mode, when the pressure at the hydraulic control end of the mode switching valve 21 drops to a certain value, the control unit 40 controls the mode control valve 22 to work in the left position for a certain period of time and then controls the mode control valve 22 to return to the middle position. When the mode control valve 22 works in the left position, the oil is added to the hydraulic control end of the mode switching valve 21 so that the mode switching valve 21 always works in the right position. The pressure detection device 23 may be a pressure sensor, a pressure switch, or a pressure relay. When the pressure at the hydraulic control end of the mode switching valve 1 is lower than a predetermined value, the control unit 40 may obtain a triggering electrical signal of the pressure detection device 23 that can be used for judgment.

[0043] In order to detect the degree of the mode switching valve 21 being reset to the left position when working in the right position, a valve stem position sensor (not shown in the figure) can also be provided. The valve stem position sensor is connected to the valve stem of the mode switching valve. When the mode switching valve 21 is reset from the right position to the left position, when it is reset to a predetermined position, the valve stem position sensor triggers to send a corresponding electrical signal to the control unit 40. In the second operation mode, when the control unit 40 receives the trigger signal of the valve stem position sensor, the control unit 40 controls the mode control valve 22 to work in the left position for a certain period of time and then controls the mode control valve 22 to return to the middle position. When the mode control valve 22 works in the left position, oil is added to the hydraulic control end of the mode switching valve 21 so that the mode switching valve always works in the right position.

[0044] In order to make the mode switching valve 21 always work in the right position in the second operating mode, it can also be achieved by periodically filling the hydraulic control end of the mode switching valve with liquid, that is, the control unit 40 controls the mode control valve 22 to periodically switch from the middle position to the left position. For this purpose, a timing module and a timing cycle can be set in the control unit 40. The control unit 40 is configured to periodically control the mode control valve 22 to switch between the left position and the middle position with a timing cycle as a period in the second operating mode.

[0045] Optionally, in the operation mode switching control system, the mode switching valve 21 has a manual switching rod 23 for manual switching. The manual switching rod 23 is connected to the valve stem of the mode switching valve 21. By pulling the manual switching rod 23, the valve stem of the mode switching valve 21 can be pushed to move, so that the mode switching valve 21 can be switched between the first operation mode and the second operation mode. The manual switching rod 23 is provided. When the mode control valve 22, the control unit 40, the mode setting device 50, etc. fail and the mode switching cannot be performed, the mode switching valve 21 can be switched to the operation mode through the manual switching rod 23.

[0046] This embodiment also provides an excavator having the aforementioned operation mode switching control system.

[0047] Embodiment 2.

[0048] Compared with the first embodiment, the operation mode switching control system of this embodiment is different in that the mode control valve 22 is used.

[0049] like Figure 2 As shown, in this embodiment, the mode control valve 22 includes a three-position four-way solenoid valve 221 and a hydraulically controlled one-way valve 222;

[0050] The first oil port (e port) of the three-position four-way solenoid valve 221 is the oil inlet port (P port), the second oil port (f port) is the oil return port (T port), the third oil port (g port) is connected to the forward conducting oil inlet end of the hydraulically controlled one-way valve 222, and the fourth oil port (h port) is connected to the hydraulic control end of the hydraulically controlled one-way valve 222; the oil outlet end of the hydraulically controlled one-way valve 22 is the control oil port (D port).

[0051] The three working positions of the three-position four-way solenoid valve 221, namely the left position, the middle position and the right position, correspond to the three working positions of the mode control valve 22, namely the left position, the middle position and the right position. When the three-position four-way solenoid valve 221 is in the left position, the first oil port (port e) is connected to the third oil port (port g); when the three-position four-way solenoid valve 221 is in the middle position, the first oil port (port e) is cut off, and at this time, the third oil port (port g) and the fourth oil port (port h) can both be connected to the second oil port (port f), thereby preventing the hydraulic control end of the hydraulic control check valve 222 from accidentally opening due to the pressure oil accumulated due to valve leakage. When in the right position, the first oil port (port e) is connected to the fourth oil port (port h), and the second oil port (port f) is connected to the third oil port (port g).

[0052] When the mode control valve 22 is in the left position, the pilot oil from the oil inlet (P port) flows through the left position oil circuit of the three-position four-way solenoid valve 221 and then flows through the hydraulic control check valve 222 to enter the hydraulic control end of the mode switching valve 21, so that the mode switching valve 21 is in the left position. When the mode control valve 22 is in the middle position, since the three-position four-way solenoid valve 221 is in the middle position and the hydraulic control check valve 21 is in the reverse cut-off state, the oil at the hydraulic control end of the mode switching valve 21 cannot leak out through the hydraulic control check valve 222 and the middle position oil circuit of the three-position four-way solenoid valve 221, thereby reducing the speed of its leakage outward. When the mode control valve 22 is in the right position, since the three-position four-way solenoid valve 221 is in the right position, the pilot pressure oil from the oil inlet (P port) acts on the hydraulic control end of the hydraulic control check valve 222 through the right position oil circuit of the three-position four-way solenoid valve 221 (the e port is connected to the h port), and the hydraulic control check valve 222 is in the reverse conduction state. The oil at the hydraulic control end of the mode switching valve 21 flows to the return oil circuit through the control oil port (D port), the right position oil circuit of the three-position four-way solenoid valve 221 (the g port is connected to the f port), and the return oil port (T port), so that the mode switching valve 21 is switched from the right position to the left position, and the operation mode switching control system is also switched from the second operation mode to the first operation mode. The valve core and the valve body of the hydraulic control check valve 222 can adopt a conical line contact seal, which has good sealing performance.

[0053] In this embodiment, the mode switching valve 21 is a hydraulically controlled valve, and is controlled by an electrically controlled mode control valve 22. In the second operation mode, the mode switching valve 21 is kept in the right position for a long time by intermittently controlling the mode control valve 22. The mode control valve 22 is intermittently energized to reduce its heat generation, reduce its failure rate, and increase its service life.

Claims

1. An operation mode switching control system, comprising a mode switching valve arranged on a pilot control oil circuit for switching between a first operation mode and a second operation mode, characterized in that: It also includes a mode control valve, a control unit, and a mode setting device; The mode switching valve is a hydraulically controlled valve; The mode control valve has a control end electrically connected to the control unit and has a control oil port connected to the hydraulic control end of the mode switching valve, an oil inlet connected to the pilot oil source, and an oil return port connected to the oil return oil circuit, and the oil inlet is connected to the control oil port when in the left position, the control oil port is cut off when in the middle position, and the control oil port is connected to the oil return port when in the right position; The mode setting device is electrically connected to the control unit and is used to input a first operation mode working instruction and a second operation mode working instruction; The control unit is used for controlling the mode control valve to intermittently switch between the left position and the middle position in the second working mode.

2. The operation mode switching control system according to claim 1, characterized in that: The control unit is configured to control the mode control valve to operate in the middle position in the first operating mode, and the mode setting device controls the mode control valve to switch to the right position and then to the middle position when the mode setting device outputs a working instruction to switch from the second operating mode to the first operating mode.

3. The operation mode switching control system according to claim 1, characterized in that: The hydraulic control end of the mode switching valve is connected to an accumulator.

4. The operation mode switching control system according to claim 1, characterized in that: The mode switching valve has a manual switching lever for manually switching the switching direction.

5. The operation mode switching control system according to claim 1, characterized in that: The mode setting device is configured as an on-vehicle instrument capable of displaying a current operation mode.

6. The operation mode switching control system according to claim 1, characterized in that: The control unit includes a timing module, and the control unit is configured to periodically control the mode control solenoid valve to switch between a left position and a middle position in a second operation mode.

7. The operation mode switching control system according to claim 1, characterized in that: The system further comprises a pressure detection device for detecting the pressure at the hydraulic control end of the mode switching valve and electrically connected to the control unit, wherein the control unit is configured to control the mode control valve to operate in the left position when the pressure at the hydraulic control end of the mode switching valve is less than a preset value in the second operation mode; Alternatively, the system further comprises a valve stem position sensor for detecting the valve stem position of the mode switching valve, and the control unit is configured to control the mode control valve to operate in the left position in the second operation mode and when the valve stem of the mode switching valve is reset to a predetermined position.

8. The operation mode switching control system according to any one of claims 1 to 7, characterized in that: The mode control valve is a three-position three-way solenoid valve.

9. The operation mode switching control system according to any one of claims 1 to 7, characterized in that: The mode control valve includes a three-position four-way solenoid valve and a hydraulically controlled one-way valve; The first oil port of the three-position four-way solenoid valve is the oil inlet port, the second oil port is the oil return port, the third oil port is connected to the forward conducting oil inlet end of the hydraulically controlled one-way valve, and the fourth oil port is connected to the hydraulically controlled end of the hydraulically controlled one-way valve; the oil outlet end of the hydraulically controlled one-way valve is the control oil port; When the three-position four-way solenoid valve is in the left position, the first oil port is connected to the third oil port, when it is in the middle position, the first oil port is blocked, and when it is in the right position, the first oil port is connected to the fourth oil port and the second oil port is connected to the third oil port.

10. An excavator having the operation mode switching control system according to any one of claims 1 to 9.

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