CN113446279B - High-pressure oil circuit switching device and hydraulic system - Google Patents

Abstract

The application provides a high-pressure oil way switching device and a hydraulic system, wherein the high-pressure oil way switching device comprises a first oil inlet and outlet, a second oil inlet and outlet, a first oil way channel, a second oil way channel, a third oil way channel, a first one-way valve, a second one-way valve and an on-off valve; the first channel port of the first oil channel is connected with the first oil inlet and outlet, the second channel port is connected with the first one-way valve, and the third channel port is connected with the on-off valve; the first channel port of the second oil channel is connected with the second oil inlet and outlet, the second channel port is connected with the first one-way valve, and the third channel port is connected with the second one-way valve; the first channel opening of the third oil channel is connected with the second one-way valve, and the second channel opening is connected with the on-off valve. By implementing the technical scheme of the application, the switching operation is more convenient and faster when the hydraulic motor and the hydraulic pump are used in a reciprocal switching manner, and the control efficiency of switching the high-pressure oil way is improved.

Description

High-pressure oil circuit switching device and hydraulic system

Technical Field

The present disclosure relates to the field of hydraulics, and in particular to a high-pressure oil circuit switching device and a hydraulic system.

Background technique

With the development of industrial automation, intelligence and integration, more and more customers who use hydraulic products have put forward higher requirements for the reliability and safety of hydraulic systems. Hydraulic motors and hydraulic pumps are the core components of hydraulic systems. In actual use, hydraulic source integrated products need to use hydraulic motors and hydraulic pumps in reverse, that is, when used in the forward direction, as a hydraulic pump, the high-pressure oil circuit outputs high-pressure oil, and when used in the reverse direction, as a hydraulic motor, the high-pressure oil circuit inputs high-pressure oil. In the prior art, when the hydraulic motor is switched to the hydraulic pump or the hydraulic pump is switched to the hydraulic motor, the technicians have to manually adjust the oil circuit channel again, which makes the operation very inconvenient when the hydraulic motor and the hydraulic pump are switched in reverse.

Summary of the invention

In order to solve at least one of the above technical problems, the present disclosure provides a high-pressure oil circuit switching device and a hydraulic system.

In a first aspect of an embodiment of the present application, a high-pressure oil circuit switching device includes a first oil inlet and outlet, a second oil inlet and outlet, a first oil channel, a second oil channel, a third oil channel, a first one-way valve, a second one-way valve and an on-off valve;

The first channel port of the first oil channel is connected to the first oil inlet and outlet, the second channel port of the first oil channel is connected to the first one-way valve, and the third channel port of the first oil channel is connected to the on-off valve;

The first channel port of the second oil passage is connected to the second oil inlet and outlet, the second channel port of the second oil passage is connected to the first one-way valve, and the third channel port of the second oil passage is connected to the second one-way valve, wherein the first one-way valve is configured to allow the second oil passage to unidirectionally conduct to the first oil passage;

The first channel port of the third oil channel is connected to the second one-way valve, and the second channel port of the third oil channel is connected to the on-off valve, wherein the second one-way valve is configured to allow the third oil channel to unidirectionally conduct to the second oil channel, and the channel valve is used to control the on-off of the first oil channel and the third oil channel.

Optionally, the high-pressure oil circuit switching device further includes a fourth oil inlet and outlet and a fourth oil circuit channel communicating with the second oil circuit channel;

The first channel opening of the fourth oil passage is connected to the fourth oil inlet and outlet, and the second channel opening of the fourth oil passage is connected to the second one-way valve, so that the third oil passage is unidirectionally conductive to the fourth oil passage.

In a third aspect of the present application, the high-pressure oil circuit switching device further includes a third oil inlet and outlet, and the third oil circuit channel has a third channel port.

The third channel opening of the third oil passage is connected to the third oil inlet and outlet.

Optionally, the first one-way valve includes a first oil inlet, a first oil outlet, a first valve body, a first spring and a first valve core;

The first valve body is provided with a first valve core cavity opening toward the first oil inlet, and the first valve core cavity is communicated with the first oil outlet and the first oil inlet respectively;

The first valve core is arranged in the first valve core cavity;

The first spring is arranged between the first valve core and the cavity wall of the first valve core cavity, and is used for driving the first valve core to be close to and seal the first oil inlet.

Optionally, the second one-way valve includes a second oil inlet, a second oil outlet, a second valve body, a second spring and a second valve core;

The second valve body is provided with a second valve core cavity with an opening facing the second oil inlet, and the second valve core cavity is communicated with the second oil outlet and the second oil inlet respectively;

The second valve core is arranged in the second valve core cavity;

The second spring is arranged between the second valve core and the cavity wall of the second valve core cavity, and is used for driving the second valve core to be close to and seal the second oil inlet.

Optionally, the first valve core cavity, the first valve core, the second valve core cavity and the second valve core are all elliptical, the outer diameter of the first valve core is the same as the diameter of the first valve core cavity, and the outer diameter of the second valve core is the same as the diameter of the second valve core cavity.

Optionally, the on-off valve includes a valve seat, a return spring, a third valve core and an electromagnetic coil;

The valve seat is provided with a first hole and a second hole;

The electromagnetic coil surrounds the outer side of the third valve core and is used to control the third valve core to move to the first position;

The return spring is connected to the third valve core and is used to control the third valve core to return to the second position;

When the third valve core is in the first position, the third valve core puts the valve seat in a first state; when the third valve core is in the second position, the third valve core puts the valve seat in a second state; the first state is that the first hole and the second hole are connected to or disconnected from each other; the second state is that the first hole and the second hole are connected to or disconnected from each other; the first state is different from the second state.

Optionally, a cavity is provided on the valve seat;

The third valve core is at least partially slidably disposed in the cavity;

An oil guide channel is provided in the third valve core, so that when the third valve core is in the first position, the oil guide channel cooperates with the first hole and the second hole to form an oil passage, and when the third valve core is in the second position, the valve core seals the first hole or the second hole.

Optionally, the cavity and the third valve core are both cylindrical, and the outer diameter of the third valve core is the same as the diameter of the cavity.

A second aspect of an embodiment of the present application is a hydraulic system, comprising a hydraulic device and a high-pressure oil circuit switching device as described in any one of the first aspects of the embodiment of the present application, wherein the hydraulic device comprises a hydraulic pump or a hydraulic motor, and the high-pressure oil circuit switching device is connected to the hydraulic device.

By implementing the technical solution of the present application, the following beneficial technical effects can be achieved: by adopting the high-pressure oil circuit switching device of the present application, the oil circuit channel when the hydraulic motor and the hydraulic pump are switched in reverse can be controlled by the on-off valve, so that the switching operation when the hydraulic motor and the hydraulic pump are switched in reverse is more convenient, and the control efficiency of the high-pressure oil circuit switching is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

FIG1 is a schematic structural diagram of a high-pressure oil circuit switching device in an embodiment of the present application;

FIG. 2 is a schematic diagram of oil circuit control of a high-pressure oil circuit switching device in an embodiment of the present application.

Detailed ways

The present disclosure is further described in detail below in conjunction with the accompanying drawings and implementations. It is understood that the specific implementations described herein are only used to explain the relevant content, rather than to limit the present disclosure. It should also be noted that, for ease of description, only the parts related to the present disclosure are shown in the accompanying drawings.

It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

Referring to FIG. 1 and FIG. 2 , a high-pressure oil circuit switching device includes a first oil inlet and outlet 1, a second oil inlet and outlet 2, a first oil circuit channel 3, a second oil circuit channel 4, a third oil circuit channel 5, a first one-way valve 6, a second one-way valve 7 and an on-off valve 8;

The first channel opening of the first oil channel 3 is connected to the first oil inlet and outlet 1, the second channel opening of the first oil channel 3 is connected to the first one-way valve 6, and the third channel opening of the first oil channel 3 is connected to the on-off valve 8;

The first channel opening of the second oil passage 4 is connected to the second oil inlet and outlet port 2, the second channel opening of the second oil passage 4 is connected to the first one-way valve 6, and the third channel opening of the second oil passage 4 is connected to the second one-way valve 7, wherein the first one-way valve 6 is configured to allow the second oil passage 4 to unidirectionally conduct to the first oil passage 3;

The first channel port of the third oil channel 5 is connected to the second one-way valve 7, and the second channel port of the third oil channel 5 is connected to the on-off valve 8, wherein the second one-way valve 7 is constructed to unidirectionally conduct the third oil channel 5 to the second oil channel 4, and the channel valve is used to control the on-off of the first oil channel 3 and the third oil channel 5.

It can be known that the first oil passage is an oil passage having at least three passage openings, the second oil passage is an oil passage having at least three passage openings, and the third oil passage is an oil passage having at least two passage openings, wherein the passage openings of the same oil passage are interconnected;

When the high-pressure oil circuit switching device in the embodiment of the present application is applied to a hydraulic pump or a hydraulic motor, the first oil inlet and outlet 1 is connected to the system high-pressure oil circuit, and the second oil inlet and outlet 2 is connected to the high-pressure oil circuit of the hydraulic pump or the hydraulic motor.

When the hydraulic pump or hydraulic motor is to be used as a hydraulic pump, it is only necessary to control the on-off valve 8 to be disconnected so that the first oil passage 3 and the third oil passage 5 are not connected. At the same time, since the second one-way valve 7 is constructed so that the third oil passage 5 is unidirectionally connected to the second oil passage 4, and since there is no high-pressure oil in the third oil passage 5 at this time, the second oil passage 4 and the third oil passage 5 are also not connected at this time; in this way, the high-pressure oil output by the hydraulic pump exerts a force on the second one-way valve 7. When the force exceeds a certain value, the second one-way valve 7 is opened, so that the high-pressure oil circuit of the hydraulic pump flows to the high-pressure oil circuit of the system;

When the hydraulic pump or hydraulic motor is to be used as a hydraulic motor, it is only necessary to control the on-off valve 8 to open so that the first oil circuit 3 is connected to the third oil circuit 5. At the same time, since the second one-way valve 7 is constructed so that the third oil circuit 5 is unidirectionally connected to the second oil circuit 4, and because there is high-pressure oil in the third oil circuit 5 at this time, the high-pressure oil will prompt the second one-way valve 7 to open, so the second oil circuit 4 is also connected to the third oil circuit 5 at this time; and since the first one-way valve 6 is constructed so that the second oil circuit 4 is unidirectionally connected to the first oil circuit 3, the high-pressure oil in the system high-pressure oil circuit is blocked by the first one-way valve 6 at this time, so that the high-pressure oil in the system high-pressure oil circuit enters the hydraulic motor from the first high-pressure oil circuit through the third high-pressure oil circuit and the second high-pressure oil circuit in sequence.

From the above, it can be seen that when implementing the high-pressure oil circuit switching device of this embodiment, it is only necessary to control the on-off of the on-off valve 8 in the high-pressure oil circuit switching device to realize the corresponding oil circuit channel switching control and isolate the oil circuit when the hydraulic motor and the hydraulic pump are switched between each other.

From the above, it can be seen that the first one-way valve 6 is used for oil discharge relative to the hydraulic pump, so the first one-way valve 6 can be called an oil discharge one-way valve, and the second one-way valve 7 is used for oil intake relative to the hydraulic motor, so the second one-way valve 7 can be called an oil intake one-way valve.

In one embodiment, referring to FIG. 1 and FIG. 2 , the high-pressure oil circuit switching device further includes a fourth oil inlet and outlet 9 and a fourth oil circuit channel 10 communicating with the second oil circuit channel 4 ;

The first channel opening of the fourth oil channel 10 is connected to the fourth oil inlet and outlet 9 , and the second channel opening of the fourth oil channel 10 is connected to the second one-way valve 7 , so that the third oil channel 5 is unidirectionally conductive to the fourth oil channel 10 .

It can be known that the fourth oil passage in this embodiment is an oil passage having at least two passage openings, wherein the passage openings of the same oil passage are interconnected.

The high-pressure oil circuit switching device further includes a third oil inlet and outlet 11 . The third oil circuit channel 5 has a third channel opening. The third channel opening of the third oil circuit channel 5 is connected to the third oil inlet and outlet 11 .

It can be known that the second oil channel in this embodiment is an oil channel having at least three channel openings, wherein the channel openings of the same oil channel are interconnected.

This embodiment is aimed at the case where a hydraulic pump or a hydraulic motor has a swash plate variable displacement mechanism.

When the hydraulic pump or hydraulic motor is used as a hydraulic pump, if there is a swash plate variable mechanism, the fourth oil inlet and outlet 9 is connected to the inlet oil circuit of the pressure control valve of the swash plate variable mechanism, and at this time, the third oil channel 5 and the second oil channel 4, as well as the third oil channel 5 and the first oil channel 3 are not connected, and the third oil channel 5 is in an isolated state. When the hydraulic pump outlet pressure does not reach the set variable pressure of the pressure control valve, the pressure control valve is closed, and the angle of the swash plate is large under the elastic force of the return spring, and it is in a large displacement state; when the pressure rises to the set variable pressure of the pressure control valve, the pressure control valve opens, and the high-pressure oil enters the follower piston chamber of the swash plate variable mechanism. Under the action of the follower piston chamber pressure, the swash plate overcomes the elastic force of the return spring, and the angle of the swash plate decreases to zero angle, and it is in a small displacement state to zero displacement state, and finally meets the constant pressure variable requirement of the hydraulic system.

When the hydraulic pump or hydraulic motor is used as hydraulic motor oil, if there is a swash plate variable mechanism, the fourth inlet and outlet oil holes are connected to the inlet oil circuit of the pressure control valve of the swash plate variable mechanism, and the third inlet and outlet oil ports 11 are connected to the oil circuit of the small end piston chamber of the swash plate variable mechanism under low load. When the motor is under low load, its inlet pressure does not reach the set variable pressure of the pressure control valve, so the pressure control valve is closed, and the swash plate angle is reduced under the action of the small end piston chamber pressure, and it is in a small displacement state; when the pressure rises to the set pressure of the pressure control valve, the pressure control valve opens, and the high-pressure oil enters the swash plate variable mechanism to interrupt the piston chamber. Since there is an area difference between the large end piston and the small end piston at this time, the swash plate angle increases under the action of the pressure difference of the pressure difference, and it is in a large displacement state, and finally meets the constant pressure variable requirement of the hydraulic motor.

In one embodiment, referring to FIG. 1 , the first one-way valve 6 includes a first valve body 61 , a first spring 62 , a first valve core 63 , a first oil inlet 64 and a first oil outlet 65 ;

The first valve body 61 is provided with a first valve core cavity 611 opening toward the first oil inlet 64, and the first valve core cavity 611 is communicated with the first oil outlet 65 and the first oil inlet 64 respectively;

The first spring 62 and the first valve core 63 are arranged in the first valve core chamber 611;

The first spring 62 is disposed between the first valve core 63 and the cavity wall of the first valve core cavity 611 , and the first spring 62 drives the first valve core 63 to be close to and seal the first oil inlet 64 .

The first valve core 63 may include a truncated cone portion, the diameter of the upper bottom surface of the truncated cone portion is smaller than the diameter of the first oil inlet 64, and the diameter of the lower bottom surface of the truncated cone portion is greater than the diameter of the first oil inlet 64. A flexible rubber layer may be provided on the outer surface of the truncated cone portion, and the first valve core 63 includes a cylindrical portion, which is combined with the lower bottom surface of the truncated cone portion, and the diameter of the cylindrical portion is the same as the diameter of the lower bottom surface of the truncated cone portion.

The first valve core cavity 611 may be a cylindrical structure having the same diameter as the cylindrical body, so that the first valve core 63 can slide smoothly in the first valve core cavity 611. It is known that when the fluid oil pressure of the first oil outlet 65 pushes the first valve core cavity 611, so that the first spring 62 is compressed, the first valve core 63 is separated from the first oil inlet 64, so that the first oil inlet 64 is connected to the first oil outlet 65.

Specifically, during use, when the thrust of the fluid in the second oil circuit channel 4 on the first valve core 63 is greater than the thrust of the elastic force of the first spring 62 on the first valve core 63, the first valve is separated from the first oil inlet 64, so that the first oil inlet 64 is connected to the first oil outlet 65; when the thrust of the fluid in the second oil circuit channel 4 on the first valve core 63 is less than the thrust of the elastic force of the first spring 62 on the first valve core 63, the first valve is tightly attached to the first oil inlet 64, so that the first oil inlet 64 is connected to the first oil outlet 65.

The high-pressure oil circuit switching device includes a valve block 12, and the first one-way valve 6 can be fixedly arranged on the valve block 12. The valve block can be the body of the high-pressure oil circuit switching device, and the corresponding first oil circuit channel, second oil circuit channel, third oil circuit channel, fourth oil circuit channel, first one-way valve, second one-way valve, etc. are arranged.

In one embodiment, referring to FIG. 1 , the second one-way valve 7 includes a second valve body 71 , a second spring 72 , a second valve core 73 , a second oil outlet 74 and a second oil inlet 75 ;

The second valve body 71 is provided with a second valve core cavity 711 opening toward the second oil inlet 75, and the second valve core cavity 711 is communicated with the second oil outlet 74 and the second oil inlet 75 respectively;

The second spring 72 and the second valve core 73 are arranged in the second valve core chamber 711;

The second spring 72 is disposed between the second valve core 73 and the cavity wall of the second valve core cavity 711 , and the second spring 72 drives the second valve core 73 to be close to and seal the second oil inlet 75 .

The structure of the second one-way valve 7 may be the same as that of the first one-way valve 6 .

In one embodiment, in order to facilitate the control of the on-off valve 8, the on-off valve 8 is an electromagnetic on-off valve 8, and the on-off of the battery on-off valve 8 is controlled by turning the power on and off.

Specifically, referring to FIG. 1 , the on-off valve 8 may include an electromagnetic coil 81 , a valve seat 82 , a third valve core 83 and a return spring 84 ;

The valve seat 82 is provided with a first hole 821 and a second hole 822;

The electromagnetic coil 81 surrounds the outer side of the third valve core 83 and is used to control the third valve core 83 to move to the first position;

The return spring 84 is connected to the third valve core 83 and is used to control the third valve core 83 to return to the second position;

Among them, when the third valve core 83 is in the first position, the third valve core 83 puts the valve seat 82 in the first state, and when the third valve core 83 is in the second position, the third valve core 83 puts the valve seat 82 in the second state. The first state is that the first hole 821 and the second hole 822 are connected to or disconnected from each other, and the second state is that the first hole 821 and the second hole 822 are connected to or disconnected from each other, and the first state is different from the second state.

The electromagnetic coil 81 surrounds the outside of the third valve core 83, so that the electromagnetic coil 81 ring can control the movement of the third valve core 83 after being energized, wherein the third valve core 83 is made of metal material, such as copper or iron; taking the first state in which the first hole 821 and the second hole 822 are interconnected, and the second state in which the first hole 821 and the second hole 822 are disconnected from each other as an example, when the electromagnetic coil 81 ring is energized, the electromagnetic coil 81 ring controls the third valve core 83 to move to the first position, at which time the third valve core 83 closes the on-off valve 8; when the electromagnetic coil 81 ring is de-energized, the spring controls the third valve core 83 to move to the second position, at which time the third valve core 83 opens the on-off valve 8.

Specifically, the valve seat 82 is provided with a cavity 823;

The third valve core 83 is at least partially slidably disposed in the cavity 823;

An oil guide channel 831 is provided in the third valve core 83, so that when the third valve core 83 is in the first position, the oil guide channel 831 cooperates with the first hole 821 and the second hole 822 to form an oil passage; when the third valve core 83 is in the second position, the third valve core 83 seals the first hole 821 or the second hole 822.

Among them, the cavity 823 can be elliptical, the third valve core 83 can be elliptical, and the outer diameter of the third valve body is the same as the diameter of the cavity 823, so that the third valve body can move along the cavity 823, referring to Figure 1. The position of the third valve core 83 in Figure 1 is the second position, and the third valve core 83 seals the second hole 822.

The oil guide channel may be formed by the cooperation of an annular groove arranged on the outer wall of the third valve core and the cavity wall of the cavity 823 .

In one embodiment, the valve seat 82 , the first valve body 61 and the second valve body 71 are integrally mounted on the valve block 12 via threaded connection.

In one embodiment, the present application discloses a hydraulic system, which includes a hydraulic device and any of the above-mentioned high-pressure oil circuit switching devices, the hydraulic device includes a hydraulic pump or a hydraulic motor, and the high-pressure oil circuit switching device is connected to the hydraulic device. How the hydraulic device is connected to the high-pressure oil circuit switching device can refer to the above content, and will not be repeated here.

In the description of this specification, the description with reference to the terms "one embodiment/method", "some embodiments/methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment/method or example are included in at least one embodiment/method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment/method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments/methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments/methods or examples described in this specification and the features of the different embodiments/methods or examples, unless they are contradictory.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims (7)

1. The high-pressure oil way switching device is characterized by comprising a first oil inlet and outlet, a second oil inlet and outlet, a first oil way channel, a second oil way channel, a third oil way channel, a first one-way valve, a second one-way valve and an on-off valve;

The first channel port of the first oil channel is connected with the first oil inlet and outlet, the second channel port of the first oil channel is connected with the first one-way valve, and the third channel port of the first oil channel is connected with the on-off valve;

the first passage port of the second oil passage is connected with the second oil inlet and outlet, the second passage port of the second oil passage is connected with the first one-way valve, and the third passage port of the second oil passage is connected with the second one-way valve, wherein the first one-way valve is configured to be in one-way conduction with the second oil passage to the first oil passage;

The first passage opening of the third oil passage is connected with the second one-way valve, the second passage opening of the third oil passage is connected with the on-off valve, the second one-way valve is configured to conduct the third oil passage to the second oil passage in a one-way manner, and the on-off valve is used for controlling the on-off of the first oil passage and the third oil passage; the high-pressure oil way switching device further comprises a fourth oil inlet and outlet and a fourth oil way channel communicated with the second oil way channel;

The first passage opening of the fourth oil passage is connected with the fourth oil inlet and outlet, and the second passage opening of the fourth oil passage is connected with the second one-way valve, so that the third oil passage is conducted unidirectionally to the fourth oil passage;

the high-pressure oil way switching device further comprises a third oil inlet and outlet, the third oil way channel is provided with a third pipeline port, and the third pipeline port of the third oil way channel is connected with the third oil inlet and outlet;

The on-off valve comprises a valve seat, a reset spring, a third valve core and an electromagnetic coil;

The valve seat is provided with a first hole and a second hole;

the electromagnetic coil surrounds the outer side of the third valve core and is used for controlling the third valve core to move to a first position;

The return spring is connected with the third valve core and is used for controlling the third valve core to return to the second position;

When the third valve core is in a first position, the third valve core enables the valve seat to be in a first state, when the third valve core is in a second position, the third valve core enables the valve seat to be in a second state, the first state is that the first hole and the second hole are mutually communicated or mutually disconnected, the second state is that the first hole and the second hole are mutually communicated or mutually disconnected, and the first state and the second state are different.

2. The high pressure oil circuit switching device of claim 1, wherein the first check valve comprises a first oil inlet, a first oil outlet, a first valve body, a first spring, and a first valve spool;

The first valve body is provided with a first valve core cavity with an opening facing the first oil inlet, and the first valve core cavity is respectively communicated with the first oil outlet and the first oil inlet;

the first valve core is arranged in the first valve core cavity;

the first spring is arranged between the first valve core and the cavity wall of the first valve core cavity and is used for driving the first valve core to be tightly attached to and seal the first oil inlet.

3. The high pressure oil circuit switching device according to claim 2, wherein the second check valve includes a second oil inlet, a second oil outlet, a second valve body, a second spring, and a second valve spool;

The second valve body is provided with a second valve core cavity with an opening facing the second oil inlet, and the second valve core cavity is respectively communicated with the second oil outlet and the second oil inlet;

The second valve core is arranged in the second valve core cavity;

The second spring is arranged between the second valve core and the cavity wall of the second valve core cavity and is used for driving the second valve core to be tightly attached to and seal the second oil inlet.

4. The high-pressure oil circuit switching device according to claim 3, wherein the first spool chamber, the first spool, the second spool chamber, and the second spool are each elliptical, an outer diameter of the first spool is the same as a diameter of the first spool chamber, and an outer diameter of the second spool is the same as a diameter of the second spool chamber.

5. The high-pressure oil path switching device according to claim 4, wherein a cavity is provided on the valve seat;

The third valve core is at least partially arranged in the cavity in a sliding way;

An oil guide channel is arranged in the third valve core, so that when the third valve core is positioned at a first position, the oil guide channel is matched with the first hole and the second hole to form an oil path channel, and when the third valve core is positioned at a second position, the valve core seals the first hole or the second hole.

6. The high pressure oil circuit switching device of claim 5, wherein the cavity and the third spool are both cylindrical, and the third spool has an outer diameter that is the same as the cavity diameter.

7. A hydraulic system, comprising a hydraulic device and the high-pressure oil path switching device according to any one of claims 1 to 6, wherein the hydraulic device comprises a hydraulic pump or a hydraulic motor, and the high-pressure oil path switching device is connected with the hydraulic device.