Adjacent vehicle driving switching valve, hydraulic system and excavator

Abstract

The invention relates to the technical field of hydraulic pressure, in order to solve the problem that hydraulic driving equipment loses the moving capacity due to power failure, the invention provides an adjacent vehicle driving switching valve, a hydraulic system and an excavator, and in the adjacent vehicle driving switching valve, two oil ports of a first switching valve are correspondingly communicated with an external working oil port and a first oil port of a first one-way conducting valve; the second oil port of the first one-way conducting valve is communicated with the working oil outlet; two oil ports of the second switch valve are correspondingly communicated with the oil return inlet and the oil return outlet; two oil ports of the second one-way conducting valve are correspondingly communicated with the working oil inlet and the working oil outlet; the working oil inlet is communicated with the hydraulic control end of the first switch valve and an oil inlet of the first one-way valve, and an oil outlet of the first one-way valve is communicated with an external working oil port; an oil inlet of the first pressure reducing valve is communicated with a second oil port of the first switch valve, and an oil outlet of the first pressure reducing valve is communicated with a pilot oil supply port and a hydraulic control end of the second switch valve; and the external oil return port is communicated with the first oil port of the second switch valve. The device is simple in structure and convenient to operate.

Description

Technical Field

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

[0002] Excavators are used in various fields, one of which is construction work on railways. After the excavator is equipped with steel wheels that can run on the rails, it can run on the rails. Construction work on the railway, such as maintenance of the railway, has an operation window period. When the train passes through the section of the construction work, the excavator must leave the railway, otherwise it will cause a train accident. Most of the existing excavators are single-power configurations. When this type of excavator is working on the railway, if its power device such as the engine, hydraulic pump, etc. fails and cannot output the pressure oil for its hydraulic system, the excavator cannot move, which may cause a train accident.

[0003] In the prior art, in order to prevent the excavator from being unable to evacuate the railway due to power failure, the common practice is to equip the excavator with a backup power system, such as a small engine and a hydraulic pump. When the power system of the excavator fails, the backup power system is activated to provide hydraulic oil for the hydraulic system of the excavator, so that the excavator can evacuate the railway. The use of a backup power system usually has the following disadvantages: the space on the excavator is limited, and there is often no extra space for installing a backup power system. The probability of a power system failure in the excavator is very low. The backup power system is not frequently operated, and it is prone to the risk of internal corrosion and aging of components, causing the backup power to fail; due to external factors, such as wading, the backup power system may fail at the same time as the power system. Summary of the invention

[0004] The technical problem to be solved by the present invention is the problem 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-failed 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 conducts one-way 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 check valve.

[0006] The first oil port and the second oil port of the first switch valve are connected to 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 connected to the working oil outlet.

[0007] 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.

[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 communicated with the second oil port of the first switch valve, and the oil outlet of the first pressure reducing valve is simultaneously communicated with the hydraulic control end and the pilot oil supply port of the second switch valve;

[0011] The external oil return port is communicated with the first oil port of the second switch 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 check 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 drive 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 opened and closed manually.

[0017] The technical solution for achieving the purpose of the present invention is: 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, 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 communicated with the working oil outlet, the oil return port of the multi-way valve is communicated with the oil return inlet, the working oil inlet is communicated with the pump port of the working pump, and the oil return outlet is communicated with the hydraulic oil tank;

[0019] The pilot switching valve is a two-position three-way valve, whose oil outlet 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 normal state is that the second oil inlet is 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 which is normally conductive, 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 of the present invention to achieve its purpose is: an excavator having the above-mentioned hydraulic system.

[0026] Compared with the prior art, when a machine or excavator with the hydraulic system of the present invention loses its mobility due to a power failure, the adjacent vehicle drive switching valve on the machine can be connected to the adjacent vehicle drive switching valve of the adjacent machine through a pipeline to obtain power input, and the mobility can be obtained with the help of the power of the adjacent vehicle. The technical solution has a simple structure and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the neighboring 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 3It is a connection diagram of an excavator with power failure taking power from an excavator with normal power.

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

[0031] Figure 5 This is a schematic diagram of the status of the adjacent vehicle drive switching valve on an excavator with 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 switch valve 301 , the second switch 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 switch valve 308 .

[0035] An excavator with normal power 101 , an excavator with faulty power 102 , a hydraulic oil pipe 103 , and a plug connector 104 . DETAILED DESCRIPTION

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

[0037] Embodiment 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 check 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 connected to the oil return inlet (H port) and the oil return 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 communicated with 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 communicated with 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 of the second switch valve 302 and the pilot oil supply port (Pp port) at the same time.

[0044] The external oil return port (port T1 ) is communicated with the first oil port of the second switch 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, and their first oil port is connected with the second oil port in the normal state.

[0046] Optionally, the first one-way guide valve 303 and the second one-way guide valve 304 can both be one-way valves, with the first oil port being the oil inlet and the second oil port being the oil outlet, and conducting when the pressure oil pressure of the first oil port is greater than the valve core opening pressure. The first one-way guide valve 303 can only conduct from the first switch valve 301 to the working oil outlet (G port), and is cut off in the reverse direction. The second one-way guide valve 304 can only conduct from the working oil inlet (D port) to the working oil outlet (G port), and is cut off in the reverse direction.

[0047] Optionally, the first one-way valve 303 and the second one-way valve 304 may also be two-position two-way sliding 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, and usually only one of the external working oil port (P1 port) and the working oil inlet (D port) has high-pressure working oil input, and the other port does not have pressure oil input. If the external working oil port (P1 port) has high-pressure working oil input, the first switch valve 301 is in the on state; if the working oil inlet (D port) has high-pressure working oil input, the first switch valve 301 is in the off state.

[0049] For the first one-way valve 303, if the first oil port has high-pressure working oil input, the oil outlet of the first pressure reducing valve has pilot control pressure oil output of a certain pressure, and the hydraulic control end of the first one-way valve 303 is affected by the pressure oil output from the first oil port or the oil outlet of the first pressure reducing valve 305, so that the valve core moves and changes direction, and the first oil port and the second oil port of the first one-way valve 303 are connected. If the first oil port of the first one-way valve 303 does not have high-pressure working oil input, the valve core of the first one-way valve 303 changes direction under the action of the spring elastic force of its spring chamber and is in a normal state, and the first oil port and the second oil port of the first one-way valve 303 are cut off in the normal state.

[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, and can also 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 guide valve 304 is connected to the first oil port of the second one-way guide valve 304, its normal state is the state where the first oil port and the second oil port are cut off (that is, the working oil inlet (D port) is connected when there is high-pressure working oil input, otherwise it is cut off). The normal state of the first one-way guide valve 303 and the second one-way guide valve 304 refers to that the force of the hydraulic control end pressure oil on the valve core is less than the force of the spring chamber spring 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 check valve 306 through the second pressure reducing valve 307 .

[0052] Optionally, both the external working oil port (P1 port) and the external oil return port (T1 port) are provided with a plug connector, or are connected with a detachable screw plug or a switch valve that is opened and closed manually. When the neighboring vehicle drive switching valve 3 is not connected to other neighboring vehicle drive switching valves 3, the external working oil port (P1 port) and the external oil return port (T1 port) of the neighboring vehicle drive switching valve 3 are closed by their plug connectors, screw plugs or switch valves.

[0053] Optionally, the neighboring vehicle drive switching valve 3 further 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 open, the first oil port and the second oil port of the third switch valve 308 are correspondingly connected to the LS inlet (F port) and the LS outlet (C port), 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. Optionally, the external LS port (LS1 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.

[0054] Embodiment 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), the first oil inlet (port Pp2) and the second oil inlet (port Pp1) are selectively 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] The external working oil port (P1 port) and the external oil return port (T1 port) are both provided with a plug connector 104. When the plug connector 104 is connected to the hydraulic pipeline 103, the plug connector 104 conducts the oil port and the hydraulic pipeline 103. After the hydraulic pipeline 103 is removed, the oil port is automatically cut off by the plug connector. The plug connector 104 can also be replaced by a detachable screw plug or a manually operated switch valve.

[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 with a removable 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 via 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 rate according to the load requirements.

[0066] The pilot switching valve 4 has no effective pressure at its hydraulic control end, so it is in a normal state, and its second oil inlet (Pp1 port) is connected to the oil outlet (A port). 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 have the hydraulic system in this embodiment. One of the two hydraulic devices is an excavator 101 with normal power, and the other is an excavator 102 with faulty power. In the excavator 102 with faulty power, the high-pressure working pressure oil required for the hydraulic system to work cannot be output due to the failure of the power unit 8 and / or the working pump 7, and the excavator 102 loses its mobility. In order to enable the excavator 102 with faulty power to have mobility, the excavator 102 with faulty power can obtain high-pressure working pressure oil from the excavator 101 with normal power, and the specific method is as follows:

[0069] like Figure 3 Figure 4 As shown, the external working oil port (P1 port), the external oil return port (T1 port), and the external LS port (LS1 port) on the adjacent vehicle drive switching valve 3 of the excavator 101 with normal power and the excavator 102 with faulty power are connected correspondingly through three hydraulic pipelines 103. If the working pump 7 is a fixed displacement pump, two hydraulic pipelines are required to connect the external working oil port (P1 port) and the external oil return port (T1 port) 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 (D port) of the neighboring vehicle drive switching valve 3 does not have high-pressure working pressure oil input, and the first switch valve 301 is in the conducting position under the elastic force of the spring in its spring chamber. The high-pressure working pressure oil from the excavator 101 with normal power acts on the first oil port of the first one-way guide valve 303 through the first switch valve 301, and the oil outlet of the first pressure reducing valve 305 outputs low-pressure pilot control pressure oil, so the first one-way guide valve 305 is turned on, and the second one-way guide valve 304 is in the cut-off state. The high-pressure working pressure oil from the excavator 101 with normal power flows to the multi-way valve 1 of the excavator 102 with faulty power through the first switch valve 301, the first one-way guide valve 303, and the working oil outlet (G port), providing high-pressure working pressure oil for each hydraulic actuator of the excavator 102 with faulty power.

[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 switch direction, 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 power failure excavator 102, the low-pressure pilot control pressure oil output by the first pressure reducing valve 305 also makes the second switch valve 302 and the third switch valve 308 in the cut-off state, and the return oil of the multi-way valve 1 in the power failure excavator 102 can only flow back to the external return oil port (T1 port) of the adjacent vehicle drive switching valve 3 in the power normal excavator 101 through the return oil inlet (H port) and the external return oil port (T1 port), and then flow back to the hydraulic oil tank 6 of the power normal excavator 101. The load feedback signal output by the multi-way valve 2 in the power failure excavator 102 can only be transmitted to the external LS port (LS1 port) of the adjacent vehicle drive switching valve 3 in the power normal excavator 101 through the LS inlet (F port) and the external LS port (LS1 port), and then transmitted to the load feedback port (PL port) of the working pump 7 of the power normal excavator 101, so that the working pump 7 of the power normal excavator 101 can adjust its displacement according to the load signal of the power failure excavator 102 and output hydraulic oil as needed.

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

[0076] In the hydraulic system or excavator of this embodiment, when a power failure occurs, it can obtain power from the neighboring vehicle by connecting the hydraulic system with a hydraulic device that is equipped with the neighboring vehicle drive switching valve 3 and has normal power through a hydraulic pipeline. When the power device of the hydraulic system is working normally, the hydraulic system can also provide power to other hydraulic devices that have power failures and are equipped with the neighboring vehicle drive switching valve 3 in the hydraulic system. The operation of obtaining hydraulic power from the neighboring vehicle or outputting hydraulic power is to use two or three hydraulic pipelines to connect the corresponding oil ports of the two devices, which is simple and convenient to operate.

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 return oil port, and includes a first one-way guide valve and a second one-way guide 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 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; The oil inlet of the first pressure reducing valve is communicated with the second oil port of the first switch valve, and the oil outlet of the first pressure reducing valve is simultaneously communicated with the hydraulic control end and the pilot oil supply port of the second switch valve; The external oil return port is communicated with the first oil port of the second switch 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 guide valve and the second one-way guide 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 communicated with the working oil outlet, the oil return port of the multi-way valve is communicated with the oil return inlet, the working oil inlet is communicated with the pump port of the working pump, and the oil return outlet is communicated with the hydraulic oil tank; The pilot switching valve is a two-position three-way valve, whose oil outlet 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 normal state is that the second oil inlet is 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 which is normally open, wherein 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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