WO2024113770A1

WO2024113770A1 - Hydraulic control system and operating machine

Info

Publication number: WO2024113770A1
Application number: PCT/CN2023/101080
Authority: WO
Inventors: 张宁
Original assignee: 上海三一重机股份有限公司
Priority date: 2022-11-30
Filing date: 2023-06-19
Publication date: 2024-06-06
Also published as: CN115853838A

Abstract

A hydraulic control system, comprising: a boom cylinder (100), an energy accumulator (200), an explosion-proof device (300), a main oil source (401), a control oil source, a damping control valve group (500) and an oil tank (402), wherein a rodless cavity of the boom cylinder (100) is connected to the main oil source or the oil tank (402) by means of the explosion-proof device (300); the energy accumulator (200) is connected to the rodless cavity of the boom cylinder (100) by means of the damping control valve group; the control oil source is connected to the damping control valve group (500); the damping control valve group (500) is connected to the explosion-proof device (300); and the control oil source is configured to deactivate the explosion-proof function of the explosion-proof device (300) by means of the damping control valve group (500), and to adjust the state of communication between the rodless cavity of the boom cylinder (100) and the energy accumulator (200). By means of such structural arrangements, the explosion-proof state of the explosion-proof device and the boom damping state of the boom cylinder can be flexibly adjusted by means of adjusting the operating state of the damping control valve group, so as to adapt to different operating conditions.

Description

Hydraulic control system and operating machinery

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese patent application No. 202211528563.9, filed on November 30, 2022, and entitled “Hydraulic control system and operating machinery”, which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to the technical field of hydraulic systems, and in particular to a hydraulic control system and an operating machine.

Background technique

A loader is an earth-moving construction machine widely used in the construction of roads, railways, buildings, hydropower, ports, mines, etc. It is mainly used for shoveling and transporting bulk materials such as soil, sand, lime, coal, etc., and can also be used for light excavation of ore, hard soil, etc. During the boom lifting process, in order to improve the safety of the operation, it is usually necessary to activate the boom explosion-proof function. During the material transportation process, in order to improve the transportation stability and comfort of the entire vehicle, it is usually necessary to activate the boom shock absorption function. At present, there is an urgent need to provide a boom hydraulic control system that can flexibly switch the boom explosion-proof function and boom shock absorption function under different working conditions.

Summary of the invention

The present application provides a hydraulic control system and an operating machine, which are used to provide a hydraulic control system capable of flexibly switching between boom explosion-proof functions and boom shock-absorbing functions under different working conditions.

According to a first aspect of the present application, a hydraulic control system is provided, including a boom cylinder, an accumulator, an explosion-proof device, a main oil source, a control oil source, a shock-absorbing control valve group and an oil tank.

The rodless chamber of the boom oil cylinder is connected to the main oil source or the oil tank via the explosion-proof device. The accumulator is connected to the rodless chamber of the boom oil cylinder via the shock-absorbing control valve group. The control oil source is connected to the shock-absorbing control valve group. The shock-absorbing control valve group is connected to the explosion-proof device. The control oil source is used to release the explosion-proof function of the explosion-proof device via the shock-absorbing control valve group, and to adjust the connection state between the rodless chamber of the boom oil cylinder and the accumulator.

According to a hydraulic control system provided by the present application, the hydraulic control system includes a boom state switching valve. The explosion-proof device includes a locking check valve and an explosion-proof state control valve.

The rodless chamber of the boom oil cylinder is connected to the boom state switching valve via the locking one-way valve. The rod chamber of the boom oil cylinder is connected to the boom state switching valve. The boom state switching valve is connected to the main oil source and the oil tank. The boom state switching valve is used to adjust the working state of the boom oil cylinder.

The working oil port of the explosion-proof state control valve is connected to the locking check valve. The damping control valve group is connected to the control oil port of the explosion-proof state control valve and is used to control the explosion-proof state control valve to adjust the working state of the locking check valve.

According to a hydraulic control system provided by the present application, the explosion-proof state control valve includes an explosion-proof position and an explosion-proof release position. The control oil port of the explosion-proof state control valve includes a first control oil port and a second control oil port. The control oil source includes a pilot pressure oil circuit. The first control oil port is connected to the oil tank. The pilot pressure oil circuit is connected to the second control oil port through the shock absorption control valve group.

When the pilot pressure oil circuit is connected to the second control oil port through the damping control valve group, the explosion-proof state control valve is in the explosion-proof release position, and the locking check valve is in a reverse flow state.

When the pilot pressure oil circuit is not connected to supply the second control oil port, the explosion-proof state control valve is switched to the explosion-proof position, and the locking check valve is in a reverse cut-off state.

According to a hydraulic control system provided by the present application, the control oil source further includes a boom lowering pilot oil circuit. The hydraulic control system further includes a shuttle valve. The boom lowering pilot oil circuit is connected to a first oil inlet of the shuttle valve. The pilot pressure oil circuit is connected to a second oil inlet of the shuttle valve via the damping control valve group. The oil outlet of the shuttle valve is connected to the second control oil port.

According to a hydraulic control system provided by the present application, the shock-absorbing control valve group includes a shock-absorbing pilot control valve and a shock-absorbing switching assembly. The control oil source also includes a pressure relief oil circuit. The pilot pressure oil circuit and the pressure relief oil circuit are connected to one side oil port of the shock-absorbing pilot control valve, and the other side oil port of the shock-absorbing pilot control valve is connected to the control oil port of the shock-absorbing switching assembly and the second oil inlet of the shuttle valve. The accumulator is connected to the rodless chamber of the boom cylinder through the working oil port of the shock-absorbing switching assembly. The shock-absorbing pilot control valve is used to switch the working position of the explosion-proof state control valve, and adjust the connection between the accumulator and the boom cylinder by controlling the working state of the shock-absorbing switching assembly. The communication state of the rodless chamber of the arm cylinder.

According to a hydraulic control system provided by the present application, the shock-absorbing pilot control valve is a two-position three-way electromagnetic reversing valve. The shock-absorbing pilot control valve includes a shock-absorbing position and a shock-absorbing release position. The three working oil ports of the shock-absorbing pilot control valve are respectively connected to the pressure relief oil circuit, the pilot pressure oil circuit and the control oil port of the shock-absorbing switching component. The second oil inlet of the shuttle valve is connected to the control oil port of the shock-absorbing switching component.

In the shock absorbing position, the pilot pressure oil circuit is connected with the control oil port of the shock absorbing switching assembly and the second oil inlet of the shuttle valve, so that the explosion-proof state control valve is switched to the explosion-proof release position, and the rodless chamber of the boom cylinder is connected with the accumulator.

When the shock absorber is in the release position, the pressure relief oil circuit is connected to the control oil port of the shock absorber switching assembly and the second oil inlet of the shuttle valve, so that the explosion-proof state control valve is switched to the explosion-proof position or the explosion-proof release position, and the rodless chamber of the boom cylinder is cut off from the accumulator.

According to a hydraulic control system provided by the present application, the shock absorption switching assembly includes a switching control valve, a first connecting valve and a second connecting valve.

The switching control valve includes a damping connection position and a damping cut-off position. The pilot pressure oil circuit is connected to the control oil port of the switching control valve through the working oil port of the damping pilot control valve, so that the switching control valve switches between the damping connection position and the damping cut-off position.

The first connecting valve is connected to the accumulator, the rodless chamber of the boom cylinder and the switching control valve. The first connecting valve includes a first connecting position and a first cut-off position. The second connecting valve is connected to the oil tank, the rod chamber of the boom cylinder and the switching control valve. The second connecting valve includes a second connecting position and a second cut-off position. The switching control valve is used to adjust the working positions of the first connecting valve and the second connecting valve.

In the state of the shock-absorbing connecting position, the first connecting valve is switched to the first connecting position, the second connecting valve is switched to the second connecting position, the rodless chamber of the boom cylinder is connected to the accumulator through the first connecting valve, and the rod chamber of the boom cylinder is connected to the oil tank through the second connecting valve.

In the state of the shock absorption cut-off position, the first connecting valve is switched to the first cut-off position, the second connecting valve is switched to the second cut-off position, the rodless chamber of the boom cylinder is cut off from the accumulator, and the rod chamber of the boom cylinder is cut off from the oil tank.

According to a hydraulic control system provided by the present application, the hydraulic control system also includes a pressure Balance control valve. The pressure balance control valve is arranged between the accumulator and the rodless chamber of the boom oil cylinder. The pressure balance control valve is used to balance the pressure between the rodless chamber of the boom oil cylinder and the accumulator.

According to a hydraulic control system provided by the present application, the pressure balance control valve is a three-position three-way hydraulically controlled reversing valve. The three-position three-way hydraulically controlled reversing valve includes an oil replenishing position, an oil draining position and an oil replenishing and draining cut-off position. The three-position three-way hydraulically controlled reversing valve includes a third control oil port and a fourth control oil port.

The three working oil ports of the three-position three-way hydraulically controlled reversing valve are respectively connected to the accumulator, the pilot pressure oil circuit and the oil tank. The third control oil port is connected to the accumulator. The fourth control oil port is connected to the rodless chamber of the boom cylinder.

When the pressure of the third control oil port is equal to the pressure of the fourth control oil port, the three-position three-way hydraulically controlled reversing valve is switched to the supplement and discharge cut-off position, and the accumulator, the pilot pressure oil circuit and the oil tank are all cut off.

When the pressure of the third control oil port is less than the pressure of the fourth control oil port, the three-position three-way hydraulically controlled reversing valve is switched to the oil replenishing position, and the pilot pressure oil circuit is connected to the accumulator.

When the pressure of the third control oil port is greater than the pressure of the fourth control oil port, the three-position three-way hydraulically controlled reversing valve is switched to the oil drain position, and the accumulator is connected to the oil tank.

According to a second aspect of the present application, a working machine is provided, comprising the hydraulic control system as described above.

In the hydraulic control system provided in the present application, the rodless chamber of the boom cylinder is connected to the main oil source or the oil tank through the explosion-proof device, and the rod chamber of the boom cylinder is connected to the oil tank or the main oil source. During the boom lifting process, the oil output from the main oil source flows into the rodless chamber of the boom cylinder through the explosion-proof device. The oil in the rod chamber of the boom cylinder flows back into the oil tank. At this time, the explosion-proof device is in an explosion-proof state. In other words, the oil output from the main oil source can be input into the rodless chamber of the boom cylinder through the explosion-proof device, and the explosion-proof device can lock the oil in the rodless chamber of the boom cylinder. When the rodless chamber hose of the boom cylinder ruptures, the explosion-proof device can lock the oil in the rodless chamber of the boom cylinder to prevent the boom from suddenly falling or falling, thereby realizing the explosion-proof function of the boom.

The control oil source is connected to the control oil port of the explosion-proof device through the shock-absorbing control device. The accumulator is connected to the rodless chamber of the boom cylinder through the shock-absorbing control valve group. The shock-absorbing control valve group can control the connection state of the control oil source and the control oil port of the explosion-proof device, and at the same time control the rodless chamber of the boom cylinder and the accumulator. That is to say, by adjusting the working state of the shock absorbing control valve group, the working state of the explosion-proof device can be controlled, and the connecting state between the accumulator and the rodless chamber of the boom cylinder can be adjusted.

Specifically, for example, the shock-absorbing control valve group includes a connected state and a cut-off state. When the shock-absorbing control valve group is in the connected state, the control oil source is input to the control oil port of the explosion-proof device through the shock-absorbing control valve group to release the explosion-proof function of the explosion-proof device; at the same time, the rodless chamber of the boom oil cylinder is connected to the accumulator through the shock-absorbing control valve group to start the boom shock-absorbing function. When the shock-absorbing control valve group is in the cut-off state, the control oil source cannot be input to the control oil port of the explosion-proof device, and the explosion-proof device maintains the explosion-proof function; at the same time, the rodless chamber of the boom oil cylinder cannot be connected to the accumulator, and the boom shock-absorbing function is released.

With this structural setting, the rodless chamber of the boom oil cylinder is connected to the accumulator through the shock-absorbing control valve group. The control oil source is connected to the control oil port of the explosion-proof device through the shock-absorbing control valve group. By adjusting the working state of the shock-absorbing control valve group, the explosion-proof state of the explosion-proof device and the boom shock-absorbing state of the boom oil cylinder can be flexibly adjusted to adapt to different working conditions.

Furthermore, in the working machine provided in the present application, since it includes the hydraulic control system as described above, it also has the advantages as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

FIG1 is a system schematic diagram of a hydraulic control system provided by the present application;

FIG. 2 is a partial enlarged view of point A in FIG. 1 .

Reference numerals:
100, boom cylinder; 200, accumulator; 300, explosion-proof device; 301, locking check valve;
302, explosion-proof state control valve; 303, explosion-proof position; 304, explosion-proof release position; 305, first control oil port; 306, second control oil port; 401, main oil source; 402, oil tank; 403, pilot pressure oil circuit; 404, boom lowering pilot oil circuit; 405, pressure relief oil circuit; 500, shock absorption control valve group; 510, shock absorption pilot control valve; 511, shock absorption position; 512, shock absorption release position; 520, switching control valve; 521, shock absorption connecting position; 522, shock absorption stop position; 530, first connecting valve; 531, first connecting position; 532, first stop position; 540, second connecting valve; 541, second connecting position; 542, second stop position; 600, Boom status switching valve; 700, shuttle valve; 800, pressure balance control valve; 801, oil replenishment level; 802, oil drain level; 803, replenishment and drain cut-off position; 804, third control oil port; 805, fourth control oil port.

Detailed ways

The following is a further detailed description of the implementation of the present application in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples. In addition, in the absence of contradiction, Those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples to make the purpose, technical solutions and advantages of the embodiments of this application clearer. The technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

A hydraulic control system and a working machine provided by the embodiment of the present application are described below in conjunction with Figures 1 and 2. It should be understood that the following description is only an illustrative implementation of the present application and does not constitute any particular limitation to the present application.

An embodiment of the first aspect of the present application provides a hydraulic control system, as shown in Figure 1, the hydraulic control system includes: a boom cylinder 100, an accumulator 200, an explosion-proof device 300, a main oil source 401, a control oil source, a shock absorbing control valve group 500 and an oil tank 402.

The rodless chamber of the boom cylinder 100 is connected to the main oil source 401 or the oil tank 402 via the explosion-proof device 300. The accumulator 200 is connected to the rodless chamber of the boom cylinder 100 via the shock-absorbing control valve group 500. The control oil source is connected to the shock-absorbing control valve group 500. The shock-absorbing control valve group 500 is connected to the explosion-proof device 300. The control oil source is used to release the explosion-proof function of the explosion-proof device 300 via the shock-absorbing control valve group 500, and adjust the connection state between the rodless chamber of the boom cylinder 100 and the accumulator 200.

In the hydraulic control system provided in the present application, the rodless chamber of the boom cylinder 100 is connected to the main oil source 401 or the oil tank 402 via the explosion-proof device 300, and the rod chamber of the boom cylinder 100 is connected to the oil tank 402 or the main oil source 401. During the boom lifting process, the oil output from the main oil source 401 flows into the rodless chamber of the boom cylinder 100 through the explosion-proof device 300. The oil in the rod chamber of the boom cylinder 100 flows back into the oil tank 402. At this time, the explosion-proof device 300 is in an explosion-proof state. That is to say, the oil output from the main oil source 401 can be input into the rodless chamber of the boom cylinder 100 through the explosion-proof device 300, and the explosion-proof device 300 can lock the oil in the rodless chamber of the boom cylinder 100. When the rodless chamber hose of the boom cylinder 100 ruptures, the explosion-proof device 300 can lock the oil in the rodless chamber of the boom cylinder 100 to prevent the boom from suddenly dropping or falling, thereby realizing the explosion-proof function of the boom.

The control oil source is connected to the control oil port of the explosion-proof device 300 through the shock-absorbing control device. The accumulator 200 is connected to the rodless chamber of the boom cylinder 100 through the shock-absorbing control valve group 500. The connection state between the control oil source and the control oil port of the explosion-proof device 300 can be controlled, and the connection state between the rodless chamber of the boom cylinder 100 and the accumulator 200 can be controlled at the same time. In other words, by adjusting the working state of the shock-absorbing control valve group 500, the working state of the explosion-proof device 300 can be controlled, and the connection state between the accumulator 200 and the rodless chamber of the boom cylinder 100 can be adjusted.

Specifically, for example, the shock control valve group 500 includes a connected state and a cut-off state. When the shock control valve group 500 is in the connected state, the control oil source is input to the control oil port of the explosion-proof device 300 through the shock control valve group 500 to release the explosion-proof function of the explosion-proof device 300; at the same time, the rodless chamber of the boom cylinder 100 is connected to the accumulator 200 through the shock control valve group 500 to start the boom shock absorption function.

When the shock absorption control valve group 500 is in the cut-off state, the control oil source cannot be input into the control oil port of the explosion-proof device 300, and the explosion-proof device 300 maintains the explosion-proof function; at the same time, the rodless chamber of the boom cylinder 100 cannot be connected with the accumulator 200, and the boom shock absorption function is released.

With this structural setting, the rodless chamber of the boom oil cylinder 100 is connected to the accumulator 200 through the shock-absorbing control valve group 500. The control oil source is connected to the control oil port of the explosion-proof device 300 through the shock-absorbing control valve group 500. By adjusting the working state of the shock-absorbing control valve group 500, the explosion-proof state of the explosion-proof device 300 and the boom shock-absorbing state of the boom oil cylinder 100 can be flexibly adjusted to adapt to different working conditions.

In one embodiment of the present application, the hydraulic control system includes a boom state switching valve 600. The explosion-proof device 300 includes a locking check valve 301 and an explosion-proof state control valve 302.

The rodless chamber of the boom cylinder 100 is connected to the boom state switching valve 600 via the locking check valve 301. The rod chamber of the boom cylinder 100 is connected to the boom state switching valve 600. The boom state switching valve 600 is connected to the main oil source 401 and the oil tank 402. The boom state switching valve 600 is used to adjust the working state of the boom cylinder 100.

The working oil port of the explosion-proof state control valve 302 is connected to the locking check valve 301. The damping control valve group 500 is connected to the control oil port of the explosion-proof state control valve 302 and is used to control the explosion-proof state control valve 302 to adjust the working state of the locking check valve 301.

In one embodiment of the present application, the explosion-proof state control valve 302 includes an explosion-proof position 303 and an explosion-proof release position 304. The control oil port of the explosion-proof state control valve 302 includes a first control oil port 305 and a second control oil port 306. The control oil source includes a pilot pressure oil circuit 403. The first control oil port 305 is connected to the oil tank 402. The pilot pressure oil circuit 403 is connected to the second control oil port 306 through the shock absorbing control valve group 500. 306 connected.

When the pilot pressure oil circuit 403 is connected to the second control oil port 306 through the damping control valve group 500, the explosion-proof state control valve 302 is in the explosion-proof release position 304, and the locking check valve 301 is in the reverse flow state;

When the pilot pressure oil circuit 403 is not connected to supply the second control oil port 306 , the explosion-proof state control valve 302 is switched to the explosion-proof position 303 , and the locking check valve 301 is in the reverse cut-off state.

Further, in one embodiment of the present application, the control oil source also includes a boom lowering pilot oil circuit 404. The hydraulic control system also includes a shuttle valve 700. The boom lowering pilot oil circuit 404 is connected to a first oil inlet of the shuttle valve 700. The pilot pressure oil circuit 403 is connected to a second oil inlet of the shuttle valve 700 via the damping control valve group 500. The oil outlet of the shuttle valve 700 is connected to the second control oil port 306.

As shown in FIG1 , in this embodiment, the hydraulic system includes two boom cylinders 100. The rodless chamber of each boom cylinder 100 is respectively provided with an explosion-proof device 300. The rodless chambers of the two boom cylinders 100 can be connected to the accumulator 200 through the shock-absorbing control valve group 500. The rod chambers of the two boom cylinders 100 are interconnected and connected to the oil tank 402 or the main oil source 401. Among them, the main oil source 401 includes a hydraulic pump.

Taking the explosion-proof device 300 on the left side of Figures 1 and 2 as an example, the explosion-proof device 300 includes a locking one-way valve 301 and an explosion-proof state control valve 302. In this embodiment, the explosion-proof state control valve 302 is a three-position four-way hydraulically controlled reversing valve. The locking one-way valve 301 includes a valve core and a valve body. The valve core is slidably installed in the valve body. The valve core and the valve body together constitute three cavities, which are respectively a first cavity located between one end of the valve core and the valve body, a second cavity located between the other end of the valve core and the valve body, and a third cavity located in the middle of the valve core. The third cavity is an annular cavity, a spring is installed in the second cavity, and the second cavity is connected to the third cavity through a damping hole.

The first working oil port and the second working oil port of the three-position four-way hydraulically controlled reversing valve are both connected to the first cavity. The third working oil port and the fourth working oil port of the three-position four-way hydraulically controlled reversing valve are connected to the second cavity and the third cavity respectively. The first control oil port 305 of the three-position four-way hydraulically controlled reversing valve is connected to the oil tank 402, and the second control oil port 306 is connected to the shock absorption control valve group 500 and the boom lowering pilot oil circuit 404 respectively through the shuttle valve 700. The three-position four-way hydraulically controlled reversing valve includes an explosion-proof position 303 and an explosion-proof release position 304. Among them, the explosion-proof release position 304 can also include a first explosion-proof release position 304 and a second explosion-proof release position 304. In this embodiment, the left position is the explosion-proof position 303, the middle position is the first explosion-proof release position 304, and the right position is the second explosion-proof release position 304. In the state of the explosion-proof position 303, the three-position four-way hydraulically controlled reversing valve is connected to the oil tank 402, and the second control oil port 306 is connected to the shock absorption control valve group 500 and the boom lowering pilot oil circuit 404 respectively. The third working oil port and the fourth working oil port of the valve are connected to each other, and the first working oil port and the second working oil port are cut off. In the state of the first explosion-proof release position 304, the fourth working oil port of the three-position four-way hydraulic control reversing valve is connected to the first working oil port, the second working oil port and the third working oil port are cut off, and a throttling damping is set between the fourth working oil port and the first working oil port. In the state of the second explosion-proof release position 304, the fourth working oil port of the three-position four-way hydraulic control reversing valve is connected to the first working oil port, and the second working oil port is connected to the third working oil port. In addition, a safety valve can also be set in the explosion-proof state control valve 302. A throttling damping and a one-way valve can also be set in parallel at the second control oil port 306.

The boom state switching valve 600 includes a lifting position, a shutoff position, and a lowering position. One side of the boom state switching valve 600 is connected to the main oil source 401 and the oil tank 402, and the other side of the boom state switching valve 600 is connected to the rod chamber and the rodless chamber of the boom cylinder 100. In the state of the lifting position, the oil output by the hydraulic pump enters the rodless chamber of the boom cylinder 100, and the oil in the rod chamber of the boom cylinder 100 flows back to the oil tank 402. In the state of the lowering position, the oil of the hydraulic pump enters the rod chamber of the boom cylinder 100, and the oil in the rodless chamber of the boom cylinder 100 flows back to the oil tank 402. In the state of the shutoff position, the rodless chamber and the rod chamber of the boom cylinder 100 are both shut off by the oil tank 402 and the hydraulic pump.

During operation, when the boom needs to be lifted, the boom state switching valve 600 is switched to the lifting position, and the hydraulic oil output by the main oil source 401 enters the locking check valve 301 through the boom state switching valve 600, and pushes the valve core of the locking check valve 301 to move, so that the hydraulic oil enters the rodless chamber of the boom cylinder 100 through the locking check valve 301. The oil in the rod chamber of the boom cylinder 100 flows back to the oil tank 402 through the boom state switching valve 600. The piston rod of the boom cylinder 100 extends and the boom is lifted. At this time, the locking check valve 301 is in a one-way cut-off state, and the oil in the rodless chamber of the boom cylinder 100 is locked and cannot flow out. Therefore, when the rodless chamber oil pipe of the boom cylinder 100 bursts, the boom cylinder 100 will not fall suddenly.

When the boom needs to be lowered, oil is passed through the boom lowering pilot oil circuit 404, so that the oil in the boom lowering pilot oil circuit 404 is input into the second control oil port 306 through the first oil inlet and the oil outlet of the shuttle valve 700. Under the action of the pressure oil, the explosion-proof state control valve 302 is switched to the explosion-proof release position 304. At the same time, the boom state switching valve 600 is switched to the lowering position. At this time, the oil in the rodless chamber of the boom cylinder 100 can flow back to the oil tank 402 through the locking check valve 301. The hydraulic oil output by the main oil source 401 is input into the rod chamber of the boom cylinder 100 through the boom state switching valve 600. The piston rod of the boom cylinder 100 contracts, and the boom is lowered.

During material transportation, it is usually necessary to switch the boom state switching valve 600 to the cut-off position. Specifically, when the boom shock absorption function needs to be activated, the shock absorption control valve group 500 is first adjusted to the connected state, and the control oil source is input into the second control oil port 306 of the explosion-proof control valve through the shock absorption control valve group 500 and the second oil inlet and oil outlet of the shuttle valve 700, so that the explosion-proof control valve is switched to the explosion-proof release position 304, and the explosion-proof function of the explosion-proof device 300 is released; at the same time, the rodless chamber of the boom oil cylinder 100 is connected to the accumulator 200 through the shock absorption control valve group 500 to activate the boom shock absorption function.

In one embodiment of the present application, the shock-absorbing control valve group 500 includes a shock-absorbing pilot control valve 510 and a shock-absorbing switching assembly. The control oil source also includes a pressure relief oil circuit 405. The pilot pressure oil circuit 403 and the pressure relief oil circuit 405 are connected to one side oil port of the shock-absorbing pilot control valve 510, and the other side oil port of the shock-absorbing pilot control valve 510 is connected to the control oil port of the shock-absorbing switching assembly and the second oil inlet of the shuttle valve 700. The accumulator 200 is connected to the rodless chamber of the boom cylinder 100 through the working oil port of the shock-absorbing switching assembly. The shock-absorbing pilot control valve 510 is used to switch the working position of the explosion-proof state control valve 302, and adjust the connection state of the accumulator 200 and the rodless chamber of the boom cylinder 100 by controlling the working state of the shock-absorbing switching assembly.

Further, in one embodiment of the present application, the shock-absorbing pilot control valve 510 is a two-position three-way electromagnetic reversing valve. The shock-absorbing pilot control valve 510 includes a shock-absorbing position 511 and a shock-absorbing release position 512. The three working oil ports of the shock-absorbing pilot control valve 510 are respectively connected to the pressure relief oil circuit 405, the pilot pressure oil circuit 403 and the control oil port of the shock-absorbing switching component. The second oil inlet of the shuttle valve 700 is connected to the control oil port of the shock-absorbing switching component. A pressure reducing valve can be installed between the pilot pressure oil circuit 403 and the working oil port of the shock-absorbing pilot control valve 510.

When in the shock absorbing position 511, the pilot pressure oil circuit 403 is connected with the control oil port of the shock absorbing switching assembly and the second oil inlet of the shuttle valve 700, so that the explosion-proof state control valve 302 is switched to the explosion-proof release position 304, and the rodless chamber of the boom cylinder 100 is connected with the accumulator 200.

When the shock absorber is in the release position 512, the pressure relief oil circuit 405 is connected to the control oil port of the shock absorber switching assembly and the second oil inlet of the shuttle valve 700, so that the explosion-proof state control valve 302 is switched to the explosion-proof position 303 or the explosion-proof release position 304, and the rodless chamber of the boom cylinder 100 and the accumulator 200 are cut off.

Furthermore, in one embodiment of the present application, the shock absorption switching assembly includes a switching control valve 520 , a first connecting valve 530 and a second connecting valve 540 .

The switching control valve 520 includes a damping connection position 521 and a damping cut-off position 522. The pilot pressure oil circuit 403 is connected to the control port of the switching control valve 520 through the working oil port of the damping pilot control valve 510. The oil port is connected so that the switching control valve 520 switches between the shock-absorbing connecting position 521 and the shock-absorbing cutting position 522.

The first connecting valve 530 is connected to the accumulator 200, the rodless chamber of the boom cylinder 100, and the switching control valve 520. The first connecting valve 530 includes a first connecting position 531 and a first stop position 532. The second connecting valve 540 is connected to the oil tank 402, the rod chamber of the boom cylinder 100, and the switching control valve 520. The second connecting valve 540 includes a second connecting position 541 and a second stop position 542. The switching control valve 520 is used to adjust the working positions of the first connecting valve 530 and the second connecting valve 540.

In the state of the shock-absorbing communication position 521, the first communication valve 530 is switched to the first communication position 531, and the second communication valve 540 is switched to the second communication position 541, the rodless chamber of the boom cylinder 100 is connected to the accumulator 200 through the first communication valve 530, and the rod chamber of the boom cylinder 100 is connected to the oil tank 402 through the second communication valve 540;

When the shock absorber cut-off position 522 is in the state, the first connecting valve 530 switches to the first cut-off position 532 , the second connecting valve 540 switches to the second cut-off position 542 , the rodless chamber of the boom cylinder 100 and the accumulator 200 are cut off, and the rod chamber of the boom cylinder 100 and the oil tank 402 are cut off.

Referring to FIG. 1 , the damping control valve group 500 includes a damping pilot control valve 510 and a damping switching assembly. The damping switching assembly includes a switching control valve 520, a first connecting valve 530, and a second connecting valve 540. For example, the damping pilot control valve 510 is a two-position three-way electromagnetic control valve. The switching control valve 520 is a two-position three-way hydraulically controlled reversing valve. The first connecting valve 530 and the second connecting valve 540 are both two-position two-way hydraulically controlled reversing valves.

The state shown in FIG. 1 is a state where the shock-absorbing pilot control valve 510 is not energized, that is, the shock-absorbing pilot control valve 510 is in the shock-absorbing release position 512. At this time, the pressure relief oil circuit 405 is connected with the control oil port on one side of the switching control valve 520 and the second oil inlet of the shuttle valve 700. In this state, the working position of the explosion-proof state control valve 302 depends on whether the boom lowering pilot oil circuit 404 has oil flowing to the second control oil port 306 of the explosion-proof state control valve 302. When the boom lowering pilot oil circuit 404 has oil flowing to the second control oil port 306, the explosion-proof state control valve 302 switches to the explosion-proof release position 304. When the boom lowering pilot oil circuit 404 has no oil flowing to the second control oil port 306, the explosion-proof state control valve 302 remains in the explosion-proof position 303. At the same time, the switching control valve 520 is in the shock-absorbing cut-off position 522. In this state, the accumulator 200 is connected to the control oil port on one side of the first communication valve 530 and the control oil port on one side of the second communication valve 540 through the switching control valve 520, so that the first communication valve 530 is switched to the first stop position 532 and the second communication valve 540 is switched to the second stop position 542. At this time, the boom cylinder 100 The rodless chamber of the boom cylinder 100 is cut off from the accumulator 200 , and the rod chamber of the boom cylinder 100 is cut off from the oil tank 402 .

When the shock-absorbing pilot control valve 510 is energized, the shock-absorbing pilot control valve 510 is in the shock-absorbing position 511. At this time, the pilot pressure oil circuit 403 is connected with the one-side control oil port of the switching control valve 520 and the second oil inlet of the shuttle valve 700. In this state, the oil in the pilot pressure oil circuit 403 can be input into the second control oil port 306 of the explosion-proof state control valve 302 through the second oil inlet of the shuttle valve 700, and the explosion-proof state control valve 302 is switched to the explosion-proof release position 304. At the same time, the switching control valve 520 is switched to the shock-absorbing communication position 521. In this state, the oil at the one-side control oil port of the first communication valve 530 and the oil at the one-side control oil port of the second communication valve 540 are depressurized into the oil tank 402 through the switching control valve 520, so that the first communication valve 530 is switched to the first communication position 531, and the second communication valve 540 is in the second communication position 541. At this time, the rodless chamber of the boom cylinder 100 is communicated with the accumulator 200 , and the rod chamber of the boom cylinder 100 is communicated with the oil tank 402 .

In one embodiment of the present application, the hydraulic control system further includes a pressure balance control valve 800. The pressure balance control valve 800 is disposed between the accumulator 200 and the rodless chamber of the boom cylinder 100. The pressure balance control valve 800 is used to balance the pressure between the rodless chamber of the boom cylinder 100 and the accumulator 200.

More specifically, in one embodiment of the present application, as shown in FIG1 , the pressure balance control valve 800 is a three-position three-way hydraulically controlled reversing valve. The three-position three-way hydraulically controlled reversing valve includes an oil replenishing position 801, an oil draining position 802, and an oil replenishing and draining stop position 803. The three-position three-way hydraulically controlled reversing valve includes a third control oil port 804 and a fourth control oil port 805.

Among them, the three working oil ports of the three-position three-way hydraulic control reversing valve are respectively connected to the accumulator 200, the pilot pressure oil circuit 403 and the oil tank 402. The third control oil port 804 is connected to the accumulator 200. The fourth control oil port 805 is connected to the rodless chamber of the boom cylinder 100. For example, a damper can also be set between the third control oil port 804 and the accumulator 200.

When the pressure of the third control oil port 804 is equal to the pressure of the fourth control oil port 805, the three-position three-way hydraulic control reversing valve is switched to the supplement and discharge cut-off position 803, and the accumulator 200 and the pilot pressure oil circuit 403 and the oil tank 402 are all cut off;

When the pressure of the third control oil port 804 is less than the pressure of the fourth control oil port 805, the three-position three-way hydraulically controlled reversing valve is switched to the oil replenishing position 801, and the pilot pressure oil circuit 403 is connected to the accumulator 200;

When the pressure of the third control oil port 804 is greater than the pressure of the fourth control oil port 805 , the three-position three-way hydraulically controlled reversing valve is switched to the oil drain position 802 , and the accumulator 200 is connected to the oil tank 402 .

With this structural setting, when the rodless chamber pressure of the boom cylinder 100 is lower than the pressure of the accumulator 200, the accumulator 200 releases pressure to the oil tank 402 through the pressure balance valve until the pressure of the accumulator 200 is equal to the rodless chamber pressure of the boom cylinder 100. When the rodless chamber pressure of the boom cylinder 100 is higher than the pressure of the accumulator 200, the oil in the pilot pressure oil circuit 403 can be replenished into the accumulator 200 until the pressure of the accumulator 200 is equal to the rodless chamber pressure of the boom cylinder 100. In this way, the stability and safety of the start-up of the boom shock absorption function can be improved.

In addition, in one embodiment of the present application, an electromagnetic shut-off valve may be provided on the boom lowering pilot oil circuit 404. When the electromagnetic shut-off valve is in a connected state, the boom lowering pilot oil circuit 404 is connected to the second control oil port 306 via the electromagnetic shut-off valve and the shuttle valve 700. When the electromagnetic shut-off valve is in a cut-off state, the boom lowering pilot oil circuit 404 is cut off from the second control oil port 306. In addition, a control device and a vehicle speed detection device may also be provided in the hydraulic system. The control device is electrically connected to the vehicle speed detection device, the electromagnetic shut-off valve and the shock-absorbing pilot control valve 510. The control device can adjust the working position of the electromagnetic shut-off valve and the shock-absorbing pilot control valve 510 based on the detection result of the vehicle speed detection device to meet different working conditions.

An embodiment of the second aspect of the present application provides a working machine, comprising the hydraulic control system as described above.

For example, the above-mentioned working machine includes a loader. When the loader performs loading operation and needs to lift the boom, the explosion-proof function of the explosion-proof device 300 is activated. When the boom needs to be lowered, the explosion-proof function of the explosion-proof device 300 is released. When materials need to be transported, the explosion-proof function of the explosion-proof device 300 is released and the shock-absorbing function of the boom is activated.

It should be understood that the above embodiment is only an illustrative embodiment of the present application and does not constitute any limitation to the present application. That is, the above working machine includes but is not limited to a loader. For example, in other embodiments of the present application, the above working machine may also include an excavator, etc.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

A hydraulic control system includes a boom cylinder, an accumulator, an explosion-proof device, a main oil source, a control oil source, a shock-absorbing control valve group and an oil tank.

Among them, the rodless chamber of the boom cylinder is connected to the main oil source or the oil tank through the explosion-proof device, the accumulator is connected to the rodless chamber of the boom cylinder through the shock-absorbing control valve group, the control oil source is connected to the shock-absorbing control valve group, and the shock-absorbing control valve group is connected to the explosion-proof device. The control oil source is used to release the explosion-proof function of the explosion-proof device through the shock-absorbing control valve group, and to adjust the connectivity between the rodless chamber of the boom cylinder and the accumulator.
The hydraulic control system according to claim 1, wherein the hydraulic control system comprises a boom state switching valve, the explosion-proof device comprises a locking check valve and an explosion-proof state control valve,

The rodless chamber of the boom oil cylinder is connected to the boom state switching valve via the locking one-way valve, the rod chamber of the boom oil cylinder is connected to the boom state switching valve, the boom state switching valve is connected to the main oil source and the oil tank, and the boom state switching valve is used to adjust the working state of the boom oil cylinder.

The working oil port of the explosion-proof state control valve is connected to the locking one-way valve, and the shock-absorbing control valve group is connected to the control oil port of the explosion-proof state control valve and is used to control the explosion-proof state control valve to adjust the working state of the locking one-way valve.
The hydraulic control system according to claim 2, wherein the explosion-proof state control valve comprises an explosion-proof position and an explosion-proof release position, the control oil port of the explosion-proof state control valve comprises a first control oil port and a second control oil port, the control oil source comprises a pilot pressure oil circuit, the first control oil port is connected to the oil tank, the pilot pressure oil circuit is connected to the second control oil port via the damping control valve group,

When the pilot pressure oil circuit is connected to the second control oil port through the damping control valve group, the explosion-proof state control valve is in the explosion-proof release position, and the locking check valve is in a reverse flow state;

When the pilot pressure oil circuit is not connected to supply the second control oil port, the explosion-proof state control valve is switched to the explosion-proof position, and the locking check valve is in a reverse cut-off state.
The hydraulic control system according to claim 3, wherein the control oil source further comprises a boom lowering pilot oil circuit, the hydraulic control system further comprises a shuttle valve, the boom lowering pilot oil circuit is connected to the first oil inlet of the shuttle valve, and the pilot pressure oil circuit is connected to the first oil inlet of the shuttle valve. The group is connected to the second oil inlet of the shuttle valve, and the oil outlet of the shuttle valve is connected to the second control oil port.
The hydraulic control system according to claim 4, wherein the shock absorber control valve group includes a shock absorber pilot control valve and a shock absorber switching assembly, the control oil source also includes a pressure relief oil circuit, the pilot pressure oil circuit and the pressure relief oil circuit are connected to one side oil port of the shock absorber pilot control valve, the other side oil port of the shock absorber pilot control valve is connected to the control oil port of the shock absorber switching assembly and the second oil inlet of the shuttle valve, the accumulator is connected to the rodless chamber of the boom cylinder through the working oil port of the shock absorber switching assembly, the shock absorber pilot control valve is used to switch the working position of the explosion-proof state control valve, and adjust the connection state between the accumulator and the rodless chamber of the boom cylinder by controlling the working state of the shock absorber switching assembly.
According to the hydraulic control system of claim 5, wherein the shock-absorbing pilot control valve is a two-position three-way electromagnetic reversing valve, the shock-absorbing pilot control valve includes a shock-absorbing position and a shock-absorbing release position, the three working oil ports of the shock-absorbing pilot control valve are respectively connected to the pressure relief oil circuit, the pilot pressure oil circuit and the control oil port of the shock-absorbing switching component, the second oil inlet of the shuttle valve is connected to the control oil port of the shock-absorbing switching component,

In the state of the shock absorption position, the pilot pressure oil circuit is connected with the control oil port of the shock absorption switching assembly and the second oil inlet of the shuttle valve, so that the explosion-proof state control valve is switched to the explosion-proof release position, and the rodless chamber of the boom oil cylinder is connected with the accumulator;

When the shock absorber is in the release position, the pressure relief oil circuit is connected to the control oil port of the shock absorber switching assembly and the second oil inlet of the shuttle valve, so that the explosion-proof state control valve is switched to the explosion-proof position or the explosion-proof release position, and the rodless chamber of the boom cylinder is cut off from the accumulator.
The hydraulic control system according to claim 6, wherein the damping switching assembly comprises a switching control valve, a first connecting valve and a second connecting valve,

The switching control valve includes a damping connection position and a damping cut-off position, and the pilot pressure oil circuit is connected to the control oil port of the switching control valve through the working oil port of the damping pilot control valve, so that the switching control valve switches between the damping connection position and the damping cut-off position.

The first connecting valve is connected to the accumulator, the rodless chamber of the boom cylinder and the switching control valve, the first connecting valve includes a first connecting position and a first cut-off position, the second connecting valve is connected to the oil tank, the rod chamber of the boom cylinder and the switching control valve, and the second The connecting valve includes a second connecting position and a second blocking position, and the switching control valve is used to adjust the working positions of the first connecting valve and the second connecting valve.

When in the shock-absorbing connecting position, the first connecting valve is switched to the first connecting position, the second connecting valve is switched to the second connecting position, the rodless chamber of the boom cylinder is connected to the accumulator through the first connecting valve, and the rod chamber of the boom cylinder is connected to the oil tank through the second connecting valve; when in the shock-absorbing stopping position, the first connecting valve is switched to the first stopping position, the second connecting valve is switched to the second stopping position, the rodless chamber of the boom cylinder is cut off from the accumulator, and the rod chamber of the boom cylinder is cut off from the oil tank.
The hydraulic control system according to claim 5, wherein the hydraulic control system further comprises a pressure balancing control valve, wherein the pressure balancing control valve is arranged between the accumulator and the rodless chamber of the boom cylinder, and the pressure balancing control valve is used to balance the pressure between the rodless chamber of the boom cylinder and the accumulator.
According to the hydraulic control system of claim 8, wherein the pressure balance control valve is a three-position three-way hydraulically controlled reversing valve, the three-position three-way hydraulically controlled reversing valve comprises an oil replenishing position, an oil draining position and an oil replenishing and draining cut-off position, the three-position three-way hydraulically controlled reversing valve comprises a third control oil port and a fourth control oil port,

The three working oil ports of the three-position three-way hydraulically controlled reversing valve are respectively connected to the accumulator, the pilot pressure oil circuit and the oil tank, the third control oil port is connected to the accumulator, and the fourth control oil port is connected to the rodless chamber of the boom cylinder.

When the pressure of the third control oil port is equal to the pressure of the fourth control oil port, the three-position three-way hydraulically controlled reversing valve is switched to the replenishment and drainage cut-off position, and the accumulator, the pilot pressure oil circuit and the oil tank are all cut off; when the pressure of the third control oil port is less than the pressure of the fourth control oil port, the three-position three-way hydraulically controlled reversing valve is switched to the replenishment position, and the pilot pressure oil circuit is connected to the accumulator; when the pressure of the third control oil port is greater than the pressure of the fourth control oil port, the three-position three-way hydraulically controlled reversing valve is switched to the drainage position, and the accumulator is connected to the oil tank.
A working machine comprises the hydraulic control system according to any one of claims 1 to 9.