Neighboring vehicle drive switching valve, hydraulic system and excavator

Abstract

The present invention relates to the field of hydraulic technology. To address the problem of hydraulically driven equipment losing its mobility due to power failure, the present invention constructs a neighboring vehicle drive switching valve, a hydraulic system, and an excavator. In the neighboring vehicle drive switching valve, two oil ports of a first switch valve are correspondingly connected to an external working oil port and a first oil port of a first one-way guide valve; a second oil port of the first one-way guide valve is connected to a working oil outlet; two oil ports of a second switch valve are correspondingly connected to a return oil inlet and a return oil outlet; two oil ports of the second one-way guide valve are correspondingly connected to a working oil inlet and a working oil outlet; the working oil inlet is connected to the hydraulic control end of the first switch valve and the oil inlet of the first one-way valve, and the oil outlet of the first one-way valve is connected to an external working oil port; the oil inlet of a first pressure reducing valve is connected to the second oil port of the first switch valve, and the oil outlet of the first pressure reducing valve is connected to the hydraulic control end of the second switch valve and a pilot oil supply port; and the external oil return port is connected to the first oil port of the second switch valve. The present invention has a simple structure and is easy to operate.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology, and more particularly to a neighboring vehicle drive switching valve, a hydraulic system and an excavator. Background Art

[0002] Excavators are used in a variety of locations, one of which is railway construction. Equipped with steel wheels capable of running on rails, excavators can operate on these tracks. Railway construction, such as maintenance, has an operating window. When a train passes through the section being worked on, the excavator must move off the track to prevent a train accident. Most existing excavators are single-powered. If a power unit, such as the engine or hydraulic pump, fails during railway construction and cannot deliver the pressurized oil required for the hydraulic system, the excavator will become immobile, potentially causing a train accident.

[0003] In the prior art, to prevent excavators from being unable to evacuate the railway due to power failure, a common practice is to equip the excavator with a backup power system, such as a small engine and hydraulic pump. In the event of a power failure, the backup power system is activated to provide hydraulic oil to the excavator's hydraulic system, allowing the excavator to evacuate the railway. However, the use of a backup power system often has the following drawbacks: limited space on the excavator often lacks spare room for a backup power system; the probability of an excavator power system failure is very low; the backup power system is not frequently operated, which can lead to internal corrosion and component aging, causing the backup power to fail; and due to external factors, such as wading through water, the backup power system may fail simultaneously with the main power system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that hydraulically driven equipment loses its ability to move due to power failure, and provides an adjacent vehicle drive switching valve, a hydraulic system and an excavator, so that the power failure machine can move with the help of the power of the adjacent equipment.

[0005] The technical solution for achieving the purpose of the present invention is: a neighboring vehicle drive switching valve, which includes a working oil inlet, a working oil outlet, a return oil inlet, a return oil outlet, a pilot oil supply port, an external working oil port and an external oil return port, and includes a first one-way guide valve and a second one-way guide valve that are one-way conductive from the first oil port to the second oil port, a first switch valve and a second switch valve that are normally conductive, a first pressure reducing valve and a first one-way valve.

[0006] The first oil port and the second oil port of the first switch valve are correspondingly communicated with the external working oil port and the first oil port of the first one-way guide valve; the second oil port of the first one-way guide valve is communicated with the working oil outlet.

[0007] The first oil port and the second oil port of the second switch valve are communicated with the return oil inlet and the return oil outlet respectively.

[0008] The first oil port and the second oil port of the second one-way valve are communicated with the hydraulic oil inlet and the hydraulic oil outlet, respectively.

[0009] The working oil inlet is communicated with the hydraulic control end of the first switch valve and the oil inlet of the first one-way valve, and the oil outlet of the first one-way valve is communicated with the external working oil port.

[0010] The oil inlet of the first pressure reducing valve is connected to the second oil port of the first switch valve, and the oil outlet of the first pressure reducing valve is connected to the hydraulic control end and the pilot oil supply port of the second switch valve at the same time;

[0011] The external oil return port is communicated with the first oil port of the second switching valve.

[0012] In the neighboring vehicle drive switching valve of the present invention, the first one-way guide valve and the second one-way guide valve are both one-way valves, or the first one-way guide valve and the second one-way guide valve are both two-position two-way sliding valves, and their hydraulic control ends are connected to their respective first oil ports or to the oil outlet of the first pressure reducing valve.

[0013] In the neighboring vehicle drive switching valve of the present invention, it also includes a second pressure reducing valve, and the working oil inlet is connected to the hydraulic control end of the first switch valve and the oil inlet of the first one-way valve through the second pressure reducing valve.

[0014] In the neighboring vehicle drive switching valve of the present invention, the external working oil port and the external oil return port are both provided with plug connectors, or are connected with detachable screw plugs or manually operated on-off valves.

[0015] In the neighboring vehicle drive switching valve of the present invention, it also includes an LS inlet, an LS outlet, an external LS port and a third switch valve which is normally conductive. The first oil port and the second oil port of the third switch valve are connected to the LS inlet and the LS outlet respectively, the external LS port is connected to the LS inlet, and the hydraulic control end of the third switch valve is connected to the oil outlet of the first pressure reducing valve.

[0016] In the neighboring vehicle driven switching valve of the present invention, the external LS port is provided with a plug connector, or is connected with a detachable screw plug or a switch valve that is manually opened and closed.

[0017] The technical solution for achieving the object of the present invention is: a hydraulic system including a multi-way valve for controlling a hydraulic actuator, a pilot valve group for controlling the multi-way valve, a pilot oil source, a working pump connected to a hydraulic oil tank, the aforementioned adjacent vehicle drive switching valve, and a pilot switching valve;

[0018] The working oil inlet of the multi-way valve is connected to the working oil outlet, the oil return port of the multi-way valve is connected to the oil return inlet, the working oil inlet is connected to the pump port of the working pump, and the oil return outlet is connected to the hydraulic oil tank;

[0019] The pilot switching valve is a two-position three-way valve, the oil outlet of which is connected to the oil inlet of the pilot valve group, the first oil inlet and the second oil inlet are connected to the pilot oil supply port and the pilot oil source respectively, the hydraulic control end is connected to the first oil inlet, and one of the first oil inlet and the second oil inlet is connected to the oil outlet, and the second oil inlet is normally connected to the oil outlet;

[0020] The external working oil port and the external oil return port are both provided with plug connectors, or are connected with detachable screw plugs or manually operated switch valves.

[0021] In the hydraulic system of the present invention, the adjacent vehicle drive switching valve further includes an LS inlet, an LS outlet, an external LS port, and a third switch valve that is normally open, wherein the first oil port and the second oil port of the third switch valve are correspondingly connected to the LS inlet and the LS outlet, the external LS port is connected to the LS inlet, and the hydraulic control end of the third switch valve is connected to the oil outlet of the first pressure reducing valve;

[0022] The working pump is a variable displacement pump, the LS port of the multi-way valve is connected to the LS inlet, and the LS outlet is connected to the load feedback port of the working pump;

[0023] The external LS port is provided with a plug connector, or is connected with a detachable screw plug or a manually operated on-off valve.

[0024] In the hydraulic system of the present invention, the pilot oil source is a pilot pump or a pilot oil supply valve whose oil inlet is connected to the pump port of the working pump.

[0025] The technical solution for achieving the purpose of the present invention is: an excavator having the above-mentioned hydraulic system.

[0026] Compared to existing technologies, this invention allows a machine or excavator equipped with this hydraulic system to obtain power input by connecting the adjacent vehicle drive switching valve on the machine to the adjacent vehicle drive switching valve on the adjacent machine via a pipeline, thereby regaining mobility with the power of the adjacent vehicle. This technical solution has a simple structure and is easy to implement and operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the adjacent vehicle drive switching valve of the present invention.

[0028] Figure 2 It is a schematic diagram of the hydraulic system of the present invention.

[0029] Figure 3This is a connection diagram of an excavator with power failure taking power from an excavator with normal power.

[0030] Figure 4 This is a hydraulic principle diagram of an excavator with power failure taking power from an excavator with normal power.

[0031] Figure 5 This is a status diagram of the adjacent vehicle drive switching valve on an excavator with a power failure.

[0032] Parts names and serial numbers in the figure:

[0033] Multi-way valve 1, pilot valve group 2, adjacent vehicle drive switching valve 3, pilot switching valve 4, pilot oil supply valve 5, hydraulic oil tank 6, working pump 7, power unit 8, oil return filter 9.

[0034] The first on-off valve 301 , the second on-off valve 302 , the first one-way valve 303 , the second one-way valve 304 , the first pressure reducing valve 305 , the first one-way valve 306 , the second pressure reducing valve 307 , and the third on-off valve 308 .

[0035] Excavator with normal power 101, excavator with power failure 102, hydraulic oil pipe 103, plug connector 104. DETAILED DESCRIPTION

[0036] The specific implementation scheme is described below with reference to the accompanying drawings.

[0037] Example 1.

[0038] like Figure 1 As shown, the neighboring vehicle drive switching valve 3 includes a working oil inlet (D port), a working oil outlet (G port), a return oil inlet (H port), a return oil outlet (E port), a pilot oil supply port (Pp port), an external working oil port (P1 port) and an external return oil port (T1 port), and includes a first one-way guide valve 303 and a second one-way guide valve 304 that conducts one-way from the first oil port to the second oil port, a first switch valve 301 and a second switch valve 302 that are normally conductive, a first pressure reducing valve 305 and a first one-way valve 306.

[0039] The first oil port and the second oil port of the first switch valve 301 are connected to the external working oil port (P1 port) and the first oil port of the first one-way valve 303; the second oil port of the first one-way valve 303 is connected to the working oil outlet (G port).

[0040] The first oil port and the second oil port of the second switch valve 302 are communicated with the return oil inlet (H port) and the return oil outlet (E port) respectively.

[0041] The first oil port and the second oil port of the second one-way valve 303 are communicated with the hydraulic oil inlet (D port) and the hydraulic oil outlet (G port) respectively.

[0042] The working oil inlet (D port) is connected to the hydraulic control end of the first switch valve 301 and the oil inlet of the first check valve 306, and the oil outlet of the first check valve 306 is connected to the external working oil port (P1 port).

[0043] The oil inlet of the first pressure reducing valve 305 is connected to the second oil port of the first switch valve 301 , and the oil outlet of the first pressure reducing valve 305 is connected to the hydraulic control end and the pilot oil supply port (Pp port) of the second switch valve 302 .

[0044] The external oil return port (port T1 ) is communicated with the first oil port of the second switching valve 302 .

[0045] The first switch valve 301 and the second switch valve 302 are both two-position two-way sliding valves. When the hydraulic oil force at the hydraulic control end is greater than the elastic force of the spring in the spring chamber, they are in the cut-off state; when the elastic force of the spring chamber is greater than the hydraulic oil force at the hydraulic control end, they are in the normal state. Under normal conditions, their first oil port and the second oil port are connected.

[0046] Alternatively, the first one-way valve 303 and the second one-way valve 304 can both be one-way valves, with their first oil port serving as the oil inlet and their second oil port serving as the oil outlet. They are open when the oil pressure at the first oil port exceeds the valve core opening pressure. The first one-way valve 303 can only conduct oil from the first on / off valve 301 toward the working oil outlet (port G), and is blocked in the reverse direction. The second one-way valve 304 can only conduct oil from the working oil inlet (port D) toward the working oil outlet (port G), and is blocked in the reverse direction.

[0047] Optionally, the first one-way valve 303 and the second one-way valve 304 may both be two-position two-way slide valves, and their respective hydraulic control ends are connected to their respective first oil ports or to the oil outlet of the first pressure reducing valve 305 .

[0048] The neighboring vehicle drive switching valve is used in a hydraulic system. Typically, only one of its external working oil port (port P1) and the working oil inlet (port D) receives high-pressure working oil, while the other port receives no pressure oil. If high-pressure working oil is flowing into the external working oil port (port P1), the first switching valve 301 is in the on state; if high-pressure working oil is flowing into the working oil inlet (port D), the first switching valve 301 is in the off state.

[0049] When high-pressure working oil is input to the first oil port of the first one-way valve 303, the oil outlet of the first pressure-reducing valve outputs pilot control pressure oil at a certain pressure. The hydraulic control end of the first one-way valve 303, under the action of the pressure oil output from the first oil port or the oil outlet of the first pressure-reducing valve 305, causes the valve core to shift and switch direction, connecting the first and second oil ports of the first one-way valve 303. When high-pressure working oil is not input to the first oil port of the first one-way valve 303, the valve core of the first one-way valve 303 switches direction under the action of the spring force of its spring chamber and enters a normal state. Under normal conditions, the first and second oil ports of the first one-way valve 303 are blocked.

[0050] For the second one-way valve 304, its hydraulic control end can be connected to the oil outlet of the first pressure reducing valve 305, or can be connected to the first oil port of the second one-way valve 304 (that is, connected to the working oil inlet (D port)). When the hydraulic control end of the second one-way valve 304 is connected to the oil outlet of the first pressure reducing valve 305, its normal state is the state where the first oil port and the second oil port are connected (such as Figure 1 ); when the hydraulic control end of the second one-way valve 304 is connected to the first oil port of the second one-way valve 304, its normal state is that the first oil port and the second oil port are blocked (that is, the working oil inlet (port D) is connected when high-pressure working oil is input, and is blocked otherwise). The normal state of the first and second one-way valves 303 and 304 is that the force exerted by the hydraulic control end pressure oil on the valve core is less than the force exerted by the spring in the spring chamber on the valve core.

[0051] Optionally, the neighboring vehicle drive switching valve 3 further includes a second pressure reducing valve 307 , and the working oil inlet (D port) is connected to the hydraulic control end of the first switch valve 301 and the oil inlet of the first one-way valve 306 through the second pressure reducing valve 307 .

[0052] Optionally, both the external working oil port (P1) and the external oil return port (T1) are provided with plug connectors, or are connected to removable screw plugs or manually operated on / off valves. When the neighboring vehicle drive switching valve 3 is not connected to another neighboring vehicle drive switching valve 3, the external working oil port (P1) and the external oil return port (T1) of the neighboring vehicle drive switching valve 3 are closed by their plug connectors, screw plugs, or on / off valves.

[0053] Optionally, the neighboring vehicle drive switching valve 3 further includes an LS inlet (port F), an LS outlet (port C), an external LS port (port LS1), and a normally open third on-off valve 308. The first and second oil ports of the third on-off valve 308 are connected to the LS inlet (port F) and LS outlet (port C), respectively. The external LS port (port LS1) is connected to the LS inlet (port F). The hydraulic control end of the third on-off valve 308 is connected to the oil outlet of the first pressure reducing valve 305. Optionally, the external LS port (port LS1) is provided with a plug connector, or is connected to a removable screw plug or a manually operated on-off valve.

[0054] Example 2.

[0055] like Figure 2 As shown, the hydraulic system includes a multi-way valve 1 for controlling the hydraulic actuator, a pilot valve group 2 for controlling the multi-way valve 1, a pilot oil source 5, a working pump 7 connected to the hydraulic oil tank 6, the aforementioned adjacent vehicle drive switching valve 3, and a pilot switching valve 4.

[0056] The working oil inlet (P port) of the multi-way valve 1 is connected to the working oil outlet (G port), the return oil port (T port) of the multi-way valve 1 is connected to the return oil inlet (H port), the working oil inlet (D port) is connected to the pump port of the working pump 7, and the return oil outlet (E port) is connected to the hydraulic oil tank 6 through the return oil filter 9.

[0057] The pilot switching valve 4 is a two-position three-way valve. In the pilot switching valve 4, the oil outlet (port A) is connected to the oil inlet (port P) of the pilot valve group 2, the first oil inlet (port Pp2) and the second oil inlet (port Pp1) are correspondingly connected to the pilot oil supply port (port Pp) and the pilot oil source 5, the hydraulic control end is connected to the first oil inlet (port Pp2), and one of the first oil inlet (port Pp2) and the second oil inlet (port Pp1) is connected to the oil outlet (port A) and the normal state is that the second oil inlet (port Pp1) is connected to the oil outlet (port A).

[0058] Both the external working oil port (P1) and the external oil return port (T1) are equipped with connectors 104. When connected to hydraulic line 103, connector 104 connects the oil port to the hydraulic line 103. When the hydraulic line 103 is disconnected, the oil port is automatically shut off by the connector. Connectors 104 can also be replaced with removable plugs or manually operated on / off valves.

[0059] Optionally, the neighboring vehicle drive switching valve 3 also includes an LS inlet (F port), an LS outlet (C port), an external LS port (LS1 port) and a third switch valve 308 which is normally conductive. The first oil port and the second oil port of the third switch valve 308 are connected to the LS inlet (F port) and the LS outlet (C port) respectively, the external LS port (LS1 port) is connected to the LS inlet (F port), and the hydraulic control end of the third switch valve 308 is connected to the oil outlet of the first pressure reducing valve 305.

[0060] The working pump 7 is a variable displacement pump. The LS port (LS port) of the multi-way valve 1 is connected to the LS inlet (F port), and the LS outlet (C port) is connected to the load feedback port (PL port) of the working pump 7 .

[0061] The external LS port (LS1 port) is provided with a plug connector, or is connected to a detachable screw plug or a manually operated on / off valve.

[0062] Optionally, the pilot oil source 5 is a pilot pump or a pilot oil supply valve whose oil inlet is connected to a pump port of the working pump 7 .

[0063] In this embodiment, when the hydraulic system is not connected to the external neighboring vehicle drive switching valve 3 through the neighboring vehicle drive switching valve 3, the external working oil port (P1 port) and the external return oil port (T1 port) are both closed and cut off, and the pressure oil output by the working pump 7 acts on the hydraulic control end of the first switch valve 301 to put it in a cut-off state. The first pressure reducing valve 305 does not output pressure oil, the second switch valve 302, the second one-way guide valve 304, and the third switch valve 308 are all in a conducting state, and the high-pressure working oil output by the working pump 7 is delivered to the multi-way valve 1 through the working oil inlet (D port) of the neighboring vehicle drive switching valve 3, the second one-way guide valve 304, and the working oil outlet (G port), and the multi-way valve 1 controls and drives each hydraulic actuator.

[0064] The return oil of each hydraulic actuator flows to the hydraulic oil tank through the return oil port (T port) of the multi-way valve 1, the return oil inlet (H port) of the adjacent vehicle drive switching valve 3, the second switch valve 302, the return oil outlet (E port), and the return oil filter 9.

[0065] The load feedback pressure signal from the multi-way valve 1 is connected to the load feedback port (PL port) of the working pump 7 through the LS inlet (F port) of the adjacent vehicle drive switching valve 3, the third switch valve 308, and the LS outlet (C port). The working pump 7 adjusts its displacement according to the pressure signal of its load feedback port (PL port) and outputs the corresponding flow according to the load requirements.

[0066] Since the pilot switching valve 4 has no effective pressure at its hydraulic end, it is in normal operation, with its second oil inlet (port Pp1) communicating with the oil outlet (port A). The pilot oil source 5 provides pilot control pressure oil to the pilot valve group 2 through the pilot switching valve 4.

[0067] The hydraulic system in this embodiment can provide high-pressure working pressure oil for the hydraulic system of other equipment. The hydraulic system of other equipment is also equipped with the adjacent vehicle drive switching valve 3 in the hydraulic system of this embodiment.

[0068] like Figure 3As shown, both hydraulic devices are equipped with the hydraulic system of this embodiment. One of the two hydraulic devices is an excavator 101 with normal power, and the other is an excavator 102 with a faulty power supply. In the faulty excavator 102, due to a failure in the power unit 8 and / or the working pump 7, the high-pressure working pressure oil required for the hydraulic system to operate cannot be output, resulting in loss of mobility. To enable the faulty excavator 102 to regain mobility, the faulty excavator 102 can obtain high-pressure working pressure oil from the normal excavator 101. The specific method is as follows:

[0069] like Figure 3 Figure 4 As shown, three hydraulic lines 103 connect the external working oil port (P1), external return oil port (T1), and external LS port (LS1) on the adjacent vehicle drive switching valve 3 of the excavator 101 with normal power and the excavator 102 with faulty power. If the working pump 7 is a fixed displacement pump, two hydraulic lines are required to connect the external working oil port (P1) and external return oil port (T1) of the two devices.

[0070] For the excavator 101 with normal power, its external working oil port (P1 port) and external return oil port (T1 port) are connected with hydraulic pipelines, which will not affect or change its hydraulic operation control. Its working pump 7 also outputs high-pressure working pressure oil to the excavator 102 with power failure through the first one-way valve 306 and the external working oil port (P1 port).

[0071] For the excavator 102 with power failure, due to the power failure, its working pump 7 cannot output high-pressure working pressure oil, and the state of each valve in the adjacent vehicle drive switching valve 3 is as follows: Figure 5 shown.

[0072] In the power failure excavator 102, as Figure 5 As shown, the working oil inlet (port D) of the neighboring vehicle drive switching valve 3 does not receive high-pressure working oil. First on-off valve 301 is in the open position due to the elastic force of the spring in its spring chamber. High-pressure working oil from the normally powered excavator 101 flows through first on-off valve 301 and acts on the first oil port of first one-way valve 303. The oil outlet of first pressure reducing valve 305 outputs low-pressure pilot control oil, thereby opening first one-way valve 305 and closing second one-way valve 304. High-pressure working oil from the normally powered excavator 101 flows through first on-off valve 301, first one-way valve 303, and the working oil outlet (port G) to multi-way valve 1 of the faulty excavator 102, providing high-pressure working oil to the hydraulic actuators of the faulty excavator 102.

[0073] The low-pressure pilot control pressure oil output by the first pressure reducing valve 305 acts on the hydraulic control end and the first oil inlet (Pp2 port) of the pilot switching valve 4 through the pilot oil supply port (Pp port), causing the pilot switching valve 4 to reverse, and its first oil inlet (Pp2 port) is connected to the oil outlet (A port), providing pilot control pressure oil for the pilot valve group 2 of the power failure excavator 102.

[0074] In the faulty excavator 102, the low-pressure pilot control oil output by the first pressure reducing valve 305 simultaneously shuts off the second on-off valve 302 and the third on-off valve 308. The return oil from the multi-way valve 1 in the faulty excavator 102 can only flow back to the external return oil port (T1) of the neighboring vehicle drive switching valve 3 in the normal excavator 101 through the return oil inlet (H) and the external return oil port (T1), and then back to the hydraulic oil tank 6 of the normal excavator 101. The load feedback signal output by the multi-way valve 2 in the faulty excavator 102 can only be transmitted to the external LS port (LS1) of the neighboring vehicle drive switching valve 3 in the normal excavator 101 through the LS inlet (F) and the external LS port (LS1), and then to the load feedback port (PL) of the working pump 7 in the normal excavator 101. This allows the working pump 7 in the normal excavator 101 to adjust its displacement based on the load signal of the faulty excavator 102 and output hydraulic oil as needed.

[0075] This embodiment also provides an excavator having the aforementioned hydraulic system.

[0076] In this embodiment, in the event of a power failure in the hydraulic system or excavator, power can be obtained from a neighboring vehicle by connecting the hydraulic system to a working hydraulic device equipped with a neighboring vehicle drive switching valve 3 via a hydraulic pipeline. While the hydraulic system's power device is functioning properly, it can also provide power to other hydraulic devices equipped with neighboring vehicle drive switching valve 3 that are experiencing power failures. The process of obtaining or distributing hydraulic power from a neighboring vehicle is simple and convenient, connecting two or three hydraulic pipelines to corresponding oil ports on the two devices.

Claims

1. A neighboring vehicle drive switching valve, characterized in that: It includes a working oil inlet, a working oil outlet, a return oil inlet, a return oil outlet, a pilot oil supply port, an external working oil port, and an external oil return port, and includes a first one-way valve and a second one-way valve for one-way conduction from the first oil port to the second oil port, a first switch valve and a second switch valve that are normally conducted, a first pressure reducing valve, and a first one-way valve; The first oil port and the second oil port of the first switch valve are correspondingly connected to the external working oil port and the first oil port of the first one-way valve; The second oil port of the first one-way valve is connected to the working oil outlet; The first oil port and the second oil port of the second switch valve are connected to the oil return inlet and the oil return outlet respectively; The first oil port and the second oil port of the second one-way valve are connected to the working oil inlet and the working oil outlet respectively; The working oil inlet is connected to the hydraulic control end of the first switch valve and the oil inlet of the first one-way valve, and the oil outlet of the first one-way valve is connected to the external working oil port; The oil inlet of the first pressure reducing valve is connected to the second oil port of the first switch valve, and the oil outlet of the first pressure reducing valve is connected to the hydraulic control end and the pilot oil supply port of the second switch valve at the same time; The external oil return port is communicated with the first oil port of the second switching valve.

2. The neighboring vehicle drive switching valve according to claim 1, characterized in that: The first one-way guide valve and the second one-way guide valve are both one-way valves; Alternatively, the first one-way valve and the second one-way valve are both two-position two-way slide valves, and their hydraulic control ends are communicated with their respective first oil ports or with the oil outlet of the first pressure reducing valve.

3. The neighboring vehicle drive switching valve according to claim 1, characterized in that: It also includes a second pressure reducing valve, and the working oil inlet is connected to the hydraulic control end of the first switch valve and the oil inlet of the first one-way valve through the second pressure reducing valve.

4. The neighboring vehicle drive switching valve according to claim 1, characterized in that: The external working oil port and the external oil return port are both provided with plug connectors, or are connected with detachable screw plugs or manually operated on-off valves.

5. The neighboring vehicle drive switching valve according to any one of claims 1 to 4, characterized in that: It also includes an LS inlet, an LS outlet, an external LS port and a third switch valve which is normally conductive. The first oil port and the second oil port of the third switch valve are connected to the LS inlet and the LS outlet respectively, the external LS port is connected to the LS inlet, and the hydraulic control end of the third switch valve is connected to the oil outlet of the first pressure reducing valve.

6. The neighboring vehicle drive switching valve according to claim 5, characterized in that: The external LS port is provided with a plug connector, or is connected with a detachable screw plug or a manually operated on-off valve.

7. A hydraulic system comprising a multi-way valve for controlling a hydraulic actuator, a pilot valve group for controlling the multi-way valve, a pilot oil source, and a working pump connected to a hydraulic oil tank; characterized in that: It also includes the adjacent vehicle drive switching valve and the pilot switching valve as described in claim 1 or 3; The working oil inlet of the multi-way valve is connected to the working oil outlet, the oil return port of the multi-way valve is connected to the oil return inlet, the working oil inlet is connected to the pump port of the working pump, and the oil return outlet is connected to the hydraulic oil tank; The pilot switching valve is a two-position three-way valve, the oil outlet of which is connected to the oil inlet of the pilot valve group, the first oil inlet and the second oil inlet are connected to the pilot oil supply port and the pilot oil source respectively, the hydraulic control end is connected to the first oil inlet, and one of the first oil inlet and the second oil inlet is connected to the oil outlet, and the second oil inlet is normally connected to the oil outlet; The external working oil port and the external oil return port are both provided with plug connectors, or are connected with detachable screw plugs or manually operated switch valves.

8. The hydraulic system according to claim 7, characterized in that: The adjacent vehicle drive switching valve further includes an LS inlet, an LS outlet, an external LS port, and a third switch valve that is normally open. The first oil port and the second oil port of the third switch valve are connected to the LS inlet and the LS outlet respectively, the external LS port is connected to the LS inlet, and the hydraulic control end of the third switch valve is connected to the oil outlet of the first pressure reducing valve. The working pump is a variable displacement pump, the LS port of the multi-way valve is connected to the LS inlet, and the LS outlet is connected to the load feedback port of the working pump; The external LS port is provided with a plug connector, or is connected with a detachable screw plug or a manually operated on-off valve.

9. The hydraulic system according to claim 7 or 8, characterized in that: The pilot oil source is a pilot pump or a pilot oil supply valve whose oil inlet is connected to the pump port of the working pump.

10. An excavator, characterized in that: It has a hydraulic system according to any one of claims 7 to 9.

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