Hydraulic control systems and operating machinery

Abstract

The present invention relates to the technical field of hydraulic systems, and proposes a hydraulic control system and an operating machine. The 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. The rodless chamber of the boom 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 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 cylinder and the accumulator. Through this structural setting, 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 cylinder can be flexibly adjusted to adapt to different working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to a hydraulic control system and an operating machine. Background Art

[0002] Loaders are a type of earthmoving machinery widely used in the construction of highways, railways, buildings, hydropower stations, ports, and mines. They are primarily used for shoveling and transporting bulk materials such as soil, sand, lime, and coal, and can also perform light excavation of ore and hard soil. During boom raising, the boom's explosion-proof function is often activated to improve operational safety. During material transportation, the boom's shock absorption function is often activated to enhance the vehicle's transport stability and comfort. Currently, there is an urgent need for a boom hydraulic control system that can flexibly switch between the boom's explosion-proof and shock absorption functions under different operating conditions. Summary of the Invention

[0003] The present invention provides a hydraulic control system and an operating machine, which are used to provide a hydraulic control system capable of flexibly switching between an explosion-proof function and a shock-absorbing function of a boom under different working conditions.

[0004] According to a first aspect of the present invention, there is provided a hydraulic control system 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.

[0005] The rodless chamber of the boom 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 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 disable the explosion-proof function of the explosion-proof device via the shock-absorbing control valve group and adjust the connection between the rodless chamber of the boom cylinder and the accumulator.

[0006] According to a hydraulic control system provided by the present invention, the hydraulic control system includes a boom state switching valve. The explosion-proof device includes a locking one-way valve and an explosion-proof state control valve.

[0007] The rodless chamber of the boom cylinder is connected to the boom state switching valve via the locking check valve. The rod chamber of the boom 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 operating state of the boom cylinder.

[0008] The working oil port of the explosion-proof state control valve is connected to the locking one-way valve. The shock absorption 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.

[0009] According to a hydraulic control system provided by the present invention, the explosion-proof state control valve includes an explosion-proof position and an explosion-proof release position. The control oil ports of the explosion-proof state control valve include 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 via the shock absorption control valve assembly.

[0010] 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 one-way valve is in a reverse flow state.

[0011] 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 one-way valve is in a reverse cut-off state.

[0012] According to a hydraulic control system provided by the present invention, 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 assembly. The shuttle valve's oil outlet is connected to the second control oil port.

[0013] According to a hydraulic control system provided by the present invention, 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 the oil port on one side of the shock-absorbing pilot control valve, and the oil port on the other side 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 to adjust the connection state between the accumulator and the rodless chamber of the boom cylinder by controlling the working state of the shock-absorbing switching assembly.

[0014] According to a hydraulic control system provided by the present invention, 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-releasing 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 assembly. The second oil inlet of the shuttle valve is connected to the control oil port of the shock-absorbing switching assembly.

[0015] When in 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 cylinder is connected with the accumulator.

[0016] 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.

[0017] According to a hydraulic control system provided by the present invention, the shock absorption switching assembly includes a switching control valve, a first connecting valve and a second connecting valve.

[0018] The switching control valve includes a damping connection position and a damping cutoff position. The pilot pressure oil circuit is connected to the control oil port of the switching control valve via 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 cutoff position.

[0019] 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 blocking 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 blocking position. The switching control valve is used to adjust the operating positions of the first and second connecting valves.

[0020] 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.

[0021] 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.

[0022] According to the present invention, a hydraulic control system further includes a pressure balancing control valve. The pressure balancing control valve is disposed between the accumulator and the rodless chamber of the boom cylinder. The pressure balancing control valve is configured to balance the pressure between the rodless chamber of the boom cylinder and the accumulator.

[0023] According to a hydraulic control system provided by the present invention, the pressure balancing control valve is a three-position, three-way hydraulically controlled directional valve. The three-position, three-way hydraulically controlled directional valve includes a replenishing oil position, a draining oil position, and a replenishing and draining cutoff position. The three-position, three-way hydraulically controlled directional valve includes a third control oil port and a fourth control oil port.

[0024] The three working oil ports of the three-position, three-way hydraulically controlled directional valve are connected to the accumulator, the pilot pressure oil circuit, and the oil tank, respectively. 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.

[0025] 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 supplemental / drainage cut-off position, and the accumulator, the pilot pressure oil circuit and the oil tank are all cut off.

[0026] When the pressure of the third control oil port is lower than the pressure of the fourth control oil port, the three-position three-way hydraulically controlled directional valve is switched to the oil replenishment position, and the pilot pressure oil circuit is connected to the accumulator.

[0027] 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.

[0028] According to a second aspect of the present invention, there is provided a working machine comprising the hydraulic control system described above.

[0029] In the hydraulic control system provided by the present invention, the rodless cavity of the boom cylinder is connected to the main oil source or the oil tank through the explosion-proof device, and the rod cavity 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 cavity of the boom cylinder through the explosion-proof device. The oil in the rod cavity of the boom cylinder flows back into the oil tank. At this time, the explosion-proof device is in an explosion-proof state. That is to say, the oil output from the main oil source can be input into the rodless cavity of the boom cylinder through the explosion-proof device, and the explosion-proof device can lock the oil in the rodless cavity of the boom cylinder. When the rodless cavity hose of the boom cylinder ruptures, the explosion-proof device can lock the oil in the rodless cavity of the boom cylinder to prevent the boom from suddenly falling or dropping, thereby realizing the explosion-proof function of the boom.

[0030] The control oil source is connected to the control oil port of the explosion-proof device via the shock-absorbing control device. The accumulator is connected to the rodless chamber of the boom cylinder via the shock-absorbing control valve group. The shock-absorbing control valve group controls the connection between the control oil source and the control oil port of the explosion-proof device, and simultaneously controls the connection between the rodless chamber of the boom cylinder and the accumulator. In other words, by adjusting the operating state of the shock-absorbing control valve group, the operating state of the explosion-proof device can be controlled, and the connection between the accumulator and the rodless chamber of the boom cylinder can be adjusted.

[0031] Specifically, for example, the shock control valve assembly has a connected state and a blocked state. When the shock control valve assembly is in the connected state, the control oil source is input through the shock control valve assembly to the control oil port of the explosion-proof device, thereby disabling the explosion-proof function of the explosion-proof device. Simultaneously, the rodless chamber of the boom cylinder is connected to the accumulator through the shock control valve assembly, activating the boom's shock absorption function. When the shock control valve assembly is in the blocked state, the control oil source cannot be input to the control oil port of the explosion-proof device, and the explosion-proof function is maintained. Simultaneously, the rodless chamber of the boom cylinder cannot communicate with the accumulator, and the boom's shock absorption function is disabling.

[0032] With this structural arrangement, the boom cylinder's rodless chamber is connected to the accumulator via the damping control valve assembly. The control oil source is connected to the explosion-proof device's control oil port via the damping control valve assembly. By adjusting the operating state of the damping control valve assembly, both the explosion-proof device's explosion-proof status and the boom cylinder's damping state can be flexibly adjusted to suit varying operating conditions.

[0033] Furthermore, in the working machine provided by the present invention, since it includes the hydraulic control system as described above, it also has the advantages as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is the system principle diagram of the hydraulic control system provided by the present invention

[0036] Figure 2 yes Figure 1 A partial enlarged view of point A in the middle;

[0037] Reference numerals:

[0038] 100, boom cylinder; 200, accumulator; 300, explosion-proof device; 301, locking check valve; 302, explosion-proof status 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 communication 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 state switching valve; 700, shuttle valve; 800, pressure balance control valve; 801, oil replenishment position; 802, oil drain position; 803, replenishment and drain stop position; 804, third control oil port; 805, fourth control oil port. DETAILED DESCRIPTION

[0039] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0040] In the description of the embodiments of the present invention, 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 invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0041] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0042] In the embodiments of the present invention, unless otherwise expressly specified or 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. Furthermore, 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 at a higher 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 at a lower level than the second feature.

[0043] 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 embodiment of the present invention. 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 can be combined in a suitable manner in any one or more embodiments or examples. In addition, in the absence of mutual 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 embodiment of the present invention clearer. The technical solutions in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] The following combination Figure 1 and Figure 2 A hydraulic control system and a working machine provided by an embodiment of the present invention are described. It should be understood that the following description is merely an illustrative embodiment of the present invention and does not constitute any particular limitation to the present invention.

[0045] An embodiment of the first aspect of the present invention provides a hydraulic control system, such as Figure 1 As shown, 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 absorption control valve group 500 and an oil tank 402 .

[0046] 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 assembly 500. The control oil source is connected to the shock-absorbing control valve assembly 500. The shock-absorbing control valve assembly 500 is connected to the explosion-proof device 300. The control oil source is used to disable the explosion-proof function of the explosion-proof device 300 via the shock-absorbing control valve assembly 500 and adjust the connection between the rodless chamber of the boom cylinder 100 and the accumulator 200.

[0047] In the hydraulic control system provided by the present invention, the rodless cavity 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 cavity 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 cavity of the boom cylinder 100 through the explosion-proof device 300. The oil in the rod cavity 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 cavity of the boom cylinder 100 through the explosion-proof device 300, and the explosion-proof device 300 can lock the oil in the rodless cavity of the boom cylinder 100. When the rodless cavity hose of the boom cylinder 100 ruptures, the explosion-proof device 300 can lock the oil in the rodless cavity of the boom cylinder 100 to prevent the boom from suddenly descending or falling, thereby realizing the explosion-proof function of the boom.

[0048] The control oil source is connected to the control oil port of the explosion-proof device 300 via the shock-absorbing control device. The accumulator 200 is connected to the rodless chamber of the boom cylinder 100 via the shock-absorbing control valve assembly 500. The shock-absorbing control valve assembly 500 controls the connection between the control oil source and the control oil port of the explosion-proof device 300, and simultaneously controls the connection between the rodless chamber of the boom cylinder 100 and the accumulator 200. In other words, by adjusting the operating state of the shock-absorbing control valve assembly 500, the operating state of the explosion-proof device 300 can be controlled, and the connection between the accumulator 200 and the rodless chamber of the boom cylinder 100 can be adjusted.

[0049] Specifically, for example, the shock control valve assembly 500 has a connected state and a blocked state. When the shock control valve assembly 500 is in the connected state, the control oil source is input through the shock control valve assembly 500 to the control oil port of the explosion-proof device 300, thereby disabling the explosion-proof function of the explosion-proof device 300. Simultaneously, the rodless chamber of the boom cylinder 100 is connected to the accumulator 200 through the shock control valve assembly 500, thereby activating the boom shock absorption function.

[0050] 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 its explosion-proof function; at the same time, the rodless chamber of the boom cylinder 100 cannot be connected to the accumulator 200, and the boom shock absorption function is released.

[0051] With this structural arrangement, the rodless chamber of the boom cylinder 100 is connected to the accumulator 200 via the damping control valve assembly 500. The control oil source is also connected to the control oil port of the explosion-proof device 300 via the damping control valve assembly 500. By adjusting the operating state of the damping control valve assembly 500, the explosion-proof state of the explosion-proof device 300 and the boom damping state of the boom cylinder 100 can be flexibly adjusted to suit different operating conditions.

[0052] In one embodiment of the present invention, 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 .

[0053] The rodless chamber of the boom cylinder 100 is connected to the boom state switching valve 600 via a 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 operating state of the boom cylinder 100.

[0054] 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.

[0055] In one embodiment of the present invention, the explosion-proof control valve 302 includes an explosion-proof position 303 and an explosion-proof release position 304. The control oil ports of the explosion-proof control valve 302 include 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 via the shock absorption control valve assembly 500.

[0056] When the pilot pressure oil circuit 403 is connected to the second control oil port 306 via the shock absorption 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;

[0057] 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 cutoff state.

[0058] Furthermore, in one embodiment of the present invention, the control oil source also includes a boom-down pilot oil circuit 404. The hydraulic control system also includes a shuttle valve 700. The boom-down pilot oil circuit 404 is connected to the first oil inlet of the shuttle valve 700. The pilot pressure oil circuit 403 is connected to the second oil inlet of the shuttle valve 700 via the shock absorption control valve assembly 500. The oil outlet of the shuttle valve 700 is connected to the second control oil port 306.

[0059] like Figure 1 As shown, in this embodiment, the hydraulic system includes two boom cylinders 100. The rodless chamber of each boom cylinder 100 is equipped with an explosion-proof device 300. The rodless chambers of both boom cylinders 100 can be connected to the accumulator 200 via a shock absorption 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. The main oil source 401 includes a hydraulic pump.

[0060] by Figure 1 and Figure 2 Taking the explosion-proof device 300 on the left side 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 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 and the third cavity are connected through a damping hole.

[0061] The first and second working oil ports of the three-position, four-way hydraulically controlled directional valve are both connected to the first chamber. The third and fourth working oil ports of the three-position, four-way hydraulically controlled directional valve are connected to the second and third chambers, respectively. The first control oil port 305 of the three-position, four-way hydraulically controlled directional 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 through the shuttle valve 700. The three-position, four-way hydraulically controlled directional valve includes an explosion-proof position 303 and an explosion-proof release position 304. 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 explosion-proof position 303, the third and fourth working oil ports of the three-position, four-way hydraulically controlled directional valve are interconnected, while the first and second working oil ports are blocked. In the first explosion-proof release position 304, the fourth working oil port of the three-position, four-way hydraulically controlled directional valve is connected to the first working oil port, while the second and third working oil ports are blocked. A throttling damper is installed between the fourth and first working oil ports. In the second explosion-proof release position 304, the fourth working oil port of the three-position, four-way hydraulically controlled directional valve is connected to the first working oil port, while the second and third working oil ports are connected. Furthermore, a safety valve may be installed within the explosion-proof control valve 302. A throttling damper and a check valve may also be installed in parallel at the second control oil port 306.

[0062] 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 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 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 shutoff position, both the rodless chamber and the rod chamber of the boom cylinder 100 are shut off by the oil tank 402 and the hydraulic pump.

[0063] 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 one-way valve 301 through the boom state switching valve 600, and pushes the valve core of the locking one-way valve 301 to move, so that the hydraulic oil enters the rodless chamber of the boom cylinder 100 through the locking one-way 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 is extended, and the boom is lifted. At this time, the locking one-way 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 oil pipe of the rodless chamber of the boom cylinder 100 bursts, the boom cylinder 100 will not suddenly fall.

[0064] When the boom needs to be lowered, oil is supplied to 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 oil outlet of the shuttle valve 700. Under the action of this pressurized 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 into the oil tank 402 through the locking one-way 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.

[0065] During material transportation, it is often necessary to switch the boom state switching valve 600 to the shutoff position, disabling the explosion-proof function and activating the boom damping function. Specifically, when the boom damping function needs to be activated, the damping control valve assembly 500 is first adjusted to the connected state. The control oil source is input into the second control oil port 306 of the explosion-proof control valve through the second oil inlet and oil outlet of the damping control valve assembly 500 and the shuttle valve 700, thereby switching the explosion-proof control valve to the explosion-proof release position 304 and disabling 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 damping control valve assembly 500 to activate the boom damping function.

[0066] In one embodiment of the present invention, the shock absorption control valve group 500 includes a shock absorption pilot control valve 510 and a shock absorption 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 absorption pilot control valve 510, and the other side oil port of the shock absorption pilot control valve 510 is connected to the control oil port of the shock absorption 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 absorption switching assembly. The shock absorption pilot control valve 510 is used to switch the working position of the explosion-proof state control valve 302, and adjust the connection state between the accumulator 200 and the rodless chamber of the boom cylinder 100 by controlling the working state of the shock absorption switching assembly.

[0067] Furthermore, in one embodiment of the present invention, the shock-absorbing pilot control valve 510 is a two-position, three-way solenoid directional control 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 assembly. The second oil inlet of the shuttle valve 700 is connected to the control oil port of the shock-absorbing switching assembly. 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.

[0068] When in the shock absorber position 511, the pilot pressure oil circuit 403 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 release position 304, and the rodless chamber of the boom cylinder 100 is connected to the accumulator 200.

[0069] 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.

[0070] Furthermore, in one embodiment of the present invention, the shock absorption switching assembly includes a switching control valve 520 , a first connecting valve 530 and a second connecting valve 540 .

[0071] The switching control valve 520 includes a damping connection position 521 and a damping cutoff position 522. The pilot pressure oil circuit 403 is connected to the control oil port of the switching control valve 520 via the working oil port of the damping pilot control valve 510, so that the switching control valve 520 switches between the damping connection position 521 and the damping cutoff position 522.

[0072] 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 blocking 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 blocking position 542. The switching control valve 520 is used to adjust the operating positions of the first connecting valve 530 and the second connecting valve 540.

[0073] 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.

[0074] 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 and 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.

[0075] refer to Figure 1 To illustrate, the shock-absorbing control valve assembly 500 includes a shock-absorbing pilot control valve 510 and a shock-absorbing switching assembly. The shock-absorbing switching assembly includes a switching control valve 520, a first connecting valve 530, and a second connecting valve 540. For example, the shock-absorbing pilot control valve 510 is a two-position, three-way solenoid-operated control valve. The switching control valve 520 is a two-position, three-way hydraulically-controlled directional control valve. The first connecting valve 530 and the second connecting valve 540 are both two-position, two-way hydraulically-controlled directional control valves.

[0076] Figure 1The illustrated state shows the shock-absorbing pilot control valve 510 de-energized, meaning it is in the shock-absorbing release position 512. At this point, the pressure relief oil circuit 405 is connected to a side control port of the switching control valve 520 and the second oil inlet of the shuttle valve 700. In this state, the operating position of the explosion-proof state control valve 302 depends on whether oil from the boom-down pilot oil circuit 404 flows to the second control port 306 of the explosion-proof state control valve 302. When oil from the boom-down pilot oil circuit 404 flows to the second control port 306, the explosion-proof state control valve 302 switches to the explosion-proof release position 304. When oil from the boom-down pilot oil circuit 404 does not flow to the second control port 306, the explosion-proof state control valve 302 remains in the explosion-proof position 303. Simultaneously, the switching control valve 520 is in the shock-absorbing cutoff position 522. In this state, the accumulator 200 is connected to one control port of the first communication valve 530 and one control port of the second communication valve 540 via the switching control valve 520, so that the first communication valve 530 is switched to the first cutoff position 532 and the second communication valve 540 is switched to the second cutoff position 542. At this time, 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.

[0077] When the shock-absorbing pilot control valve 510 is energized, it is in the shock-absorbing position 511. At this point, the pilot pressure oil circuit 403 is connected to the control port on one side of the switching control valve 520 and the second oil inlet of the shuttle valve 700. In this state, oil in the pilot pressure oil circuit 403 can be input into the second control port 306 of the explosion-proof state control valve 302 through the second oil inlet of the shuttle valve 700, causing the explosion-proof state control valve 302 to switch to the explosion-proof release position 304. Simultaneously, the switching control valve 520 is switched to the shock-absorbing communication position 521. In this state, oil at the control port on one side of the first connecting valve 530 and the control port on one side of the second connecting valve 540 are depressurized into the oil tank 402 through the switching control valve 520, causing the first connecting valve 530 to switch to the first communication position 531 and the second connecting valve 540 to switch to 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 .

[0078] In one embodiment of the present invention, the hydraulic control system further includes a pressure balancing control valve 800. The pressure balancing control valve 800 is disposed between the accumulator 200 and the rodless chamber of the boom cylinder 100. The pressure balancing control valve 800 is used to balance the pressure between the rodless chamber of the boom cylinder 100 and the accumulator 200.

[0079] More specifically, in one embodiment of the present invention, Figure 1As shown, the pressure balance control valve 800 is a three-position, three-way hydraulically controlled directional valve. The three-position, three-way hydraulically controlled directional valve includes an oil replenishment position 801, an oil drain position 802, and a replenishment and drain cutoff position 803. The three-position, three-way hydraulically controlled directional valve includes a third control oil port 804 and a fourth control oil port 805.

[0080] The three working oil ports of the three-position, three-way hydraulically controlled directional valve are connected to the accumulator 200, the pilot pressure oil circuit 403, and the oil tank 402, respectively. 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 be provided between the third control oil port 804 and the accumulator 200.

[0081] 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 hydraulically controlled reversing valve switches to the supplement-drain cutoff position 803, and the accumulator 200, the pilot pressure oil circuit 403, and the oil tank 402 are all cut off;

[0082] When the pressure of the third control oil port 804 is lower than the pressure of the fourth control oil port 805, the three-position three-way hydraulically controlled reversing valve switches to the oil replenishment position 801, and the pilot pressure oil circuit 403 is connected to the accumulator 200;

[0083] 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 switches to the oil drain position 802 , and the accumulator 200 is connected to the oil tank 402 .

[0084] With this structural arrangement, when the rodless chamber pressure of the boom cylinder 100 falls below the pressure in the accumulator 200, the accumulator 200 releases pressure into the oil tank 402 through the pressure-balancing valve until the pressure in the accumulator 200 equals the rodless chamber pressure of the boom cylinder 100. When the rodless chamber pressure of the boom cylinder 100 exceeds the pressure in the accumulator 200, oil in the pilot pressure oil circuit 403 replenishes the accumulator 200 until the pressure in the accumulator 200 equals the rodless chamber pressure of the boom cylinder 100. This improves the smoothness and safety of the activation of the boom damping function.

[0085] Furthermore, in one embodiment of the present invention, a solenoid shutoff valve may be provided on the boom-lowering pilot oil circuit 404. When the solenoid shutoff valve is in a connected state, the boom-lowering pilot oil circuit 404 is connected to the second control oil port 306 via the solenoid shutoff valve and the shuttle valve 700. When the solenoid shutoff valve is in a closed state, the boom-lowering pilot oil circuit 404 is cut off from the second control oil port 306. Furthermore, 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 solenoid shutoff valve, and the shock-absorbing pilot control valve 510. The control device can adjust the operating positions of the solenoid shutoff valve and the shock-absorbing pilot control valve 510 based on the detection results of the vehicle speed detection device to meet different operating conditions.

[0086] An embodiment of the second aspect of the present invention provides a working machine including the hydraulic control system described above.

[0087] For example, the aforementioned working machine includes a loader. When the loader is performing a loading operation and the boom needs to be raised, 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 deactivated. When materials need to be transferred, the explosion-proof function of the explosion-proof device 300 is deactivated and the boom's shock-absorbing function is activated.

[0088] It should be understood that the above embodiment is merely an illustrative embodiment of the present invention and does not constitute any limitation on the present invention. That is, the above-mentioned working machine includes, but is not limited to, a loader. For example, in other embodiments of the present invention, the above-mentioned working machine may also include an excavator, etc.

[0089] Furthermore, in the working machine provided by the present invention, since it includes the hydraulic control system as described above, it also has the advantages as described above.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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 make equivalent replacements for some of the technical features therein. 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 various embodiments of the present invention.

Claims

1. A hydraulic control system, characterized in that: Including boom cylinder, accumulator, explosion-proof device, main oil source, control oil source, shock absorption control valve group and oil tank, The rodless chamber of the boom 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 cylinder via 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 via the shock-absorbing control valve group and adjust the communication state between the rodless chamber of the boom cylinder and the accumulator; The hydraulic control system includes a boom state switching valve, and the explosion-proof device includes a locking one-way 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 absorption 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.

2. The hydraulic control system according to claim 1, characterized in that: 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 shock absorption control valve group, the explosion-proof state control valve is in the explosion-proof release position, and the locking one-way valve is in the 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 one-way valve is in a reverse cut-off state.

3. The hydraulic control system according to claim 2, characterized in that: The control oil source also includes a boom lowering pilot oil circuit, and the hydraulic control system also includes 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 second oil inlet of the shuttle valve through the shock absorption control valve group, and the oil outlet of the shuttle valve is connected to the second control oil port.

4. The hydraulic control system according to claim 3, characterized in that: The shock absorber control valve group includes a shock absorber pilot control valve and a shock absorber switching assembly, and 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, and 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 communication state between the accumulator and the rodless chamber of the boom cylinder by controlling the working state of the shock absorber switching assembly.

5. The hydraulic control system according to claim 4, characterized in that: 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 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.

6. The hydraulic control system according to claim 5, characterized in that: The damping switching assembly includes a switching control valve, a first connecting valve and a second connecting valve. The switching control valve includes a shock-absorbing connecting position and a shock-absorbing cutting 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 shock-absorbing pilot control valve, so that the switching control valve switches between the shock-absorbing connecting position and the shock-absorbing cutting position. The first connecting valve is connected to the accumulator, the rodless chamber of the boom cylinder and the switching control valve, and 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 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-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.

7. The hydraulic control system according to claim 4, characterized in that: The hydraulic control system further includes a pressure balancing control valve, which is disposed between the accumulator and the rodless chamber of the boom cylinder and is used to balance the pressure between the rodless chamber of the boom cylinder and the accumulator.

8. The hydraulic control system according to claim 7, characterized in that: The pressure balance control valve is a three-position three-way hydraulically controlled reversing valve, which includes an oil replenishment position, an oil drain position, and a replenishment and drain 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, 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 switches 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 switches 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 switches to the drain position, and the accumulator is connected to the oil tank.

9. A working machine, characterized in that: Comprising a hydraulic control system according to any one of claims 1 to 8.

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