A working device adaptive positioning hydraulic system, snow thrower and engineering machinery

Abstract

The present application discloses an adaptive positioning hydraulic system for a working device, a snow thrower and engineering machinery. The hydraulic system comprises: at least two sets of hydraulic drive branches arranged in parallel, the oil inlets of the hydraulic drive branches are connected to the oil outlets of the hydraulic pumps, and the oil return ports are connected to the hydraulic oil tanks. Each set of hydraulic drive branches comprises a three-position four-way electrically controlled reversing valve, a stroke limit valve, a two-position three-way hydraulically controlled reversing valve, a one-way speed regulating valve, a hydraulic cylinder and a damper. The present application can help the working device to achieve fast and accurate positioning, reduce the frequency of repeated operations due to over-positioning or under-positioning of the working device and the problem of poor construction effect, and improve work efficiency and operation effect; in addition, the hydraulic system can also significantly reduce the impact of the working device's movement, improve the safety of the equipment and the comfort of operation; the present application has the advantages of simple structural composition, low economic cost and simple and convenient debugging method.

Description

Technical Field

[0001] The present application relates to the field of hydraulic technology, and in particular, to a working device adaptive positioning hydraulic system, a snow thrower, and engineering machinery. Background Art

[0002] Modern engineering machinery is constantly developing in the direction of intelligent control, but it also needs to cope with a variety of complex and changeable harsh working conditions. The operational convenience and reliability of its working devices are always facing severe challenges. When the working device of the equipment has a relatively high frequency of movement and requires a certain degree of control accuracy, manual operation alone will greatly increase the difficulty of control, and the work efficiency will also be greatly reduced. At this time, a simple, convenient, reliable and practical control method is needed to assist the equipment in improving work efficiency and work quality. At the same time, engineering machinery at home and abroad is also gradually developing in the direction of large-scale design. When the load of the working device increases to a certain extent, the single hydraulic cylinder action form is not enough to provide sufficient driving force. There is also the risk of overload and strain on the hydraulic cylinder during the movement of the working device. At this time, in order to ensure the driving force and safety requirements, a dual hydraulic cylinder structure is generally adopted. At this time, the working device with a dual hydraulic cylinder structure is also in urgent need of a simple and reliable control method that can ensure the synchronous action of the dual hydraulic cylinders.

[0003] For example, a snow thrower's working device includes an auger snow collection mechanism, an impeller snow throwing mechanism, a snow thrower rotating mechanism, a skid mechanism, and the entire working device lifting mechanism. For large snow throwers, the working device is characterized by heavy structural weight and asymmetrical loads on both sides. When workers use snow throwers to clear intermittently snow-covered roads, the working device must be raised and lowered frequently. If the working device continues to descend after contacting the ground, it will press too hard against the ground, causing the snow thrower's drive wheels to lift upward. This increases vehicle resistance and reduces the adhesion of the drive wheels, making the vehicle more susceptible to slipping. If the worker stops descending prematurely, the snow thrower's snow plow will be too far from the ground, resulting in incomplete removal of snow close to the ground, seriously affecting snow removal efficiency. Faced with these challenges, a reliable and practical control method is urgently needed to achieve rapid and precise positioning of the snow thrower's working device.

[0004] On the other hand, due to the heavy load and uneven load distribution on the left and right sides of the snow thrower's working mechanism, dual hydraulic cylinders are typically used in actual engineering applications to raise and lower the working mechanism. During this process, the different loads on the two hydraulic cylinders can cause speed discrepancies, significantly impacting the lifting performance and efficiency of the working mechanism. Given these issues, a simple and reliable control method is urgently needed to achieve synchronized movement of the two hydraulic cylinders on the snow thrower's working mechanism. Summary of the Invention

[0005] The present application provides a working device adaptive positioning hydraulic system to solve the technical problems of speed asynchrony and insufficient positioning accuracy during the operation of the working device of the existing snow thrower.

[0006] The technical solutions adopted in this application are as follows:

[0007] A working device adaptive positioning hydraulic system, comprising:

[0008] At least two sets of hydraulic drive branches are arranged in parallel, the oil inlets of the hydraulic drive branches are connected to the oil outlets of the hydraulic pumps, and the oil return ports are connected to the hydraulic oil tanks. Each set of hydraulic drive branches includes a three-position four-way electrically controlled reversing valve, a stroke limit valve, a two-position three-way hydraulically controlled reversing valve, two one-way speed regulating valves, a hydraulic cylinder, and a damper, wherein:

[0009] The A port of the three-position four-way electrically controlled reversing valve is connected in sequence to one of the one-way speed regulating valves and the rodless chamber of the hydraulic cylinder through a pipeline, the B port of the three-position four-way electrically controlled reversing valve is connected to the P port and the control oil port of the two-position three-way hydraulically controlled reversing valve, the P port of the two-position three-way hydraulically controlled reversing valve is cut off, the A port of the two-position three-way hydraulically controlled reversing valve is connected in sequence to another one-way speed regulating valve and the rod chamber of the hydraulic cylinder through a pipeline, and the T port of the two-position three-way hydraulically controlled reversing valve is connected to the hydraulic oil tank;

[0010] The damper is arranged between the control oil port and the T port of the two-position three-way hydraulically controlled reversing valve;

[0011] The stroke limit valve is connected and arranged on the pipeline that needs to be cut off between the three-position four-way electrically controlled reversing valve and the hydraulic cylinder. The reversing pressure rod of the stroke limit valve is arranged relative to the pressure rod mechanism corresponding to the working device. When the pressure rod mechanism moves to press the reversing pressure rod of the stroke limit valve, the stroke limit valve gradually switches the working position.

[0012] Furthermore, the stroke limit valve is connected and arranged on the pipeline between the A port of the three-position four-way electrically controlled reversing valve and the rodless chamber of the hydraulic cylinder.

[0013] Furthermore, the stroke limit valve is connected and arranged on the pipeline between the B port of the three-position four-way electrically controlled reversing valve and the rod chamber of the hydraulic cylinder.

[0014] Furthermore, the stroke limit valve is connected to the pipeline between the A port of the three-position four-way electrically controlled reversing valve and the rodless chamber of the hydraulic cylinder, and the pipeline between the B port of the three-position four-way electrically controlled reversing valve and the rod chamber of the hydraulic cylinder.

[0015] Furthermore, a balancing valve is provided between the rodless cavity of the hydraulic cylinder and the connected one-way speed regulating valve, and between the rod cavity of the hydraulic cylinder and the connected one-way speed regulating valve.

[0016] Furthermore, a hydraulic lock is provided between the rodless cavity of the hydraulic cylinder and the connected one-way speed regulating valve, and between the rod cavity of the hydraulic cylinder and the connected one-way speed regulating valve.

[0017] Furthermore, the three-position four-way electrically controlled directional valve adopts a Y-type mid-position function electromagnetic directional valve.

[0018] Furthermore, the movement direction of the working device is vertical or horizontal.

[0019] Furthermore, a safety valve is provided between the oil outlet of the hydraulic pump and the hydraulic oil tank.

[0020] On the other hand, the present application also provides an engineering machine, including the above-mentioned working device adaptive positioning hydraulic system.

[0021] On the other hand, the present application also provides a snow thrower, including the above-mentioned working device adaptive positioning hydraulic system.

[0022] Compared with the existing technology, this application has the following beneficial effects:

[0023] 1) This application installs the stroke limit valve related to the throttling effect and the reversing pressure rod stroke in the working oil circuit of the hydraulic cylinder respectively, and uses the pressure rod mechanism of the working device to press the reversing pressure rod of the stroke limit valve after reaching the specified position during the descent process, so that the working oil circuit of the working device begins to produce a throttling effect and begins to decelerate, thereby causing the reversing speed of the reversing pressure rod of the stroke limit valve to decrease accordingly, and finally forming a closed-loop control circuit in which the descent speed of the working device is adaptively reduced, and finally the stroke limit valve is completely reversed to cut off the relevant working oil circuit of the working device, thereby achieving the purpose of gradually decelerating and finally stopping smoothly and automatically after the working device reaches the specified position during the descent process. This system can help the working device achieve fast and accurate positioning, reduce the frequency of repeated operations due to over-positioning or under-positioning of the working device, and the problem of poor construction results, thereby improving work efficiency and work results. At the same time, the hydraulic system can also significantly reduce the impact of the working device's movements, improve the safety of the equipment and the comfort of operation.

[0024] 2) This application uses a one-way speed regulating valve whose flow rate is independent of the load and is installed between the rod chamber, rodless chamber and the corresponding working oil circuit of the three-position four-way electrically controlled reversing valve of the hydraulic cylinder of the working device. During the lifting process of the working device, the multiple hydraulic cylinders of the working device can be moved synchronously, and the movement speed of the multiple hydraulic cylinders or the overall movement speed of the working device can be adjusted according to the actual working conditions. That is, when the extension and retraction speeds of the multiple hydraulic cylinders of the working device are inconsistent, the lifting and retraction speeds can be adjusted by adjusting the one-way speed regulating valves corresponding to the corresponding hydraulic cylinders, thereby ensuring the synchronous extension and retraction of the multiple hydraulic cylinders. When the overall lifting and retraction movement of the working device is too slow or too fast, the lifting and retraction speeds of the various hydraulic cylinders can be adjusted synchronously by adjusting the corresponding one-way speed regulating valves at the same time, thereby achieving the purpose of speed regulation of the working device, thereby improving the accuracy of the synchronous movement of the various hydraulic cylinders of the working device and the working efficiency of the equipment.

[0025] 3) The present application adopts at least two three-position four-way electrically controlled reversing valves connected in parallel between each hydraulic cylinder and the oil pump of the working device, and can realize simultaneous or separate movement of the two hydraulic cylinders of the working device through electrical signal control. That is, when the hydraulic cylinders of the working device need to move synchronously, the three-position four-way reversing valves can be controlled by electrical signals to be energized at the same time. At this time, each hydraulic cylinder maintains synchronous extension and retraction. When one of the hydraulic cylinders of the working device needs to move alone, the corresponding three-position four-way reversing valve can be controlled by electrical signals to be energized. At this time, only one hydraulic cylinder maintains extension and retraction, thereby realizing synchronous or separate movement of each hydraulic cylinder of the working device to meet the needs of different construction conditions.

[0026] 4) The present application has the advantages of strong functionality, diversified operation, simple structure, low economic cost, and simple and convenient debugging method.

[0027] In addition to the above-described purposes, features, and advantages, this application also has other purposes, features, and advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0029] Figure 1 This is a schematic diagram of the principle of the adaptive positioning hydraulic system of the working device of the preferred embodiment of this application.

[0030] In the figure, 1. first hydraulic cylinder; 2. second hydraulic cylinder; 3. first balancing valve; 4. second balancing valve; 5. third balancing valve; 6. fourth balancing valve; 7. first one-way speed regulating valve; 8. second one-way speed regulating valve; 9. third one-way speed regulating valve; 10. fourth one-way speed regulating valve; 11. first two-position three-way hydraulically controlled reversing valve; 12. second two-position three-way hydraulically controlled reversing valve; 13. first damper; 14. second damper; 15. first stroke limit valve; 16. second stroke limit valve; 17. first three-position four-way electrically controlled reversing valve; 18. second three-position four-way electrically controlled reversing valve; 19. safety valve; 20. hydraulic pump; 21. engine; 22. hydraulic oil tank. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] like Figure 1 The preferred embodiment of the present application provides an adaptive positioning hydraulic system for a working device, which can be applied to engineering machinery such as snow throwers, including a first hydraulic cylinder 1, a second hydraulic cylinder 2, a first balancing valve 3, a second balancing valve 4, a third balancing valve 5, a fourth balancing valve 6, a first one-way speed regulating valve 7, a second one-way speed regulating valve 8, a third one-way speed regulating valve 9, a fourth one-way speed regulating valve 10, a first two-position three-way hydraulically controlled reversing valve 11, a second two-position three-way hydraulically controlled reversing valve 12, a first damper 13, a second damper 14, a first stroke limit valve 15, a second stroke limit valve 16, a first three-position four-way electrically controlled reversing valve 17, a second three-position four-way electrically controlled reversing valve 18, a safety valve 19, and a hydraulic oil tank 22, wherein:

[0033] The output end of the snow thrower's engine 21 is connected to the input end of the hydraulic pump 20 to provide driving force for the hydraulic pump 20. The oil suction port of the hydraulic pump 20 is connected to the hydraulic oil tank 22. The oil outlet of the hydraulic pump 20 is respectively connected to the oil inlet of the safety valve 19 and the P ports of the first three-position four-way electrically controlled reversing valve 17 and the second three-position four-way electrically controlled reversing valve 18.

[0034] Port A of the first three-position, four-way electrically controlled directional control valve 17 is connected to the oil inlet of the first one-way speed regulating valve 7, and port B of the first three-position, four-way electrically controlled directional control valve 17 is connected to the oil inlet of the first stroke limit valve 15. The oil outlet of the first stroke limit valve 15 is connected to port P and the control oil port of the first two-position, three-way hydraulically controlled directional control valve 11. Port P of the first two-position, three-way hydraulically controlled directional control valve 11 is blocked, and port A of the first two-position, three-way hydraulically controlled directional control valve 11 is connected to the oil inlet of the second one-way speed regulating valve 8.

[0035] Port A of the second three-position, four-way electrically controlled directional control valve 18 is connected to the oil inlet of the third one-way speed regulating valve 9, and port B of the second three-position, four-way electrically controlled directional control valve 18 is connected to the oil inlet of the second stroke limit valve 16. The oil outlet of the second stroke limit valve 16 is connected to port P and the control oil port of the second two-position, three-way hydraulically controlled directional control valve 12. Port P of the second two-position, three-way hydraulically controlled directional control valve 12 is blocked, and port A of the second two-position, three-way hydraulically controlled directional control valve 12 is connected to the oil inlet of the fourth one-way speed regulating valve 10.

[0036] The first damper 13 is connected to the control oil port and T port of the first two-position three-way hydraulically controlled reversing valve 11, and is used to unload the control oil port of the first two-position three-way hydraulically controlled reversing valve 11; the second damper 14 is connected to the control oil port and T port of the second two-position three-way hydraulically controlled reversing valve 12, and is used to unload the control oil port of the second two-position three-way hydraulically controlled reversing valve 12.

[0037] The first three-position four-way electrically controlled directional valve 17 and the second three-position four-way electrically controlled directional valve 18 adopt a Y-type neutral position function, and the first stroke limit valve 15 and the second stroke limit valve 16 adopt a stop valve whose throttling effect is related to the movement stroke of its reversing pressure rod.

[0038] The oil outlet of the first one-way speed regulating valve 7 is connected to the oil inlet of the first balancing valve 3, the oil outlet of the second one-way speed regulating valve 8 is connected to the oil inlet of the second balancing valve 4, the oil outlet of the third one-way speed regulating valve 9 is connected to the oil inlet of the third balancing valve 5, and the oil outlet of the fourth one-way speed regulating valve 10 is connected to the oil inlet of the fourth balancing valve 6.

[0039] The load port of the first balancing valve 3 is connected to the rodless chamber of the first hydraulic cylinder 1, and the load port of the second balancing valve 4 is connected to the rod chamber of the first hydraulic cylinder 1; the load port of the third balancing valve 5 is connected to the rodless chamber of the second hydraulic cylinder 2, and the load port of the fourth balancing valve 6 is connected to the rod chamber of the second hydraulic cylinder 2.

[0040] The T ports of the first three-position four-way electrically controlled directional valve 17 , the second three-position four-way electrically controlled directional valve 18 , the safety valve 19 , the first two-position three-way hydraulically controlled directional valve 11 , and the second two-position three-way hydraulically controlled directional valve 12 are connected to the hydraulic oil tank 22 .

[0041] The descending process of the snow thrower working device is that oil enters the rod cavity of the first hydraulic cylinder 1 and the second hydraulic cylinder 2, and at the same time, oil is communicated between the P port and the A port of the first two-position three-way hydraulically controlled reversing valve 11 and the second two-position three-way hydraulically controlled reversing valve 12; the ascending process of the working device is that oil enters the rodless cavity of the first hydraulic cylinder 1 and the second hydraulic cylinder 2, and at the same time, oil is communicated between the A port and the T port of the first two-position three-way hydraulically controlled reversing valve 11 and the second two-position three-way hydraulically controlled reversing valve 12.

[0042] The first balancing valve 3 and the third balancing valve 5 play a role in maintaining pressure and stabilizing flow during the descent of the working device; the second balancing valve 4 and the fourth balancing valve 6 play a role in maintaining pressure during the snow removal operation or the lifting process of the snow thrower. As an alternative, each balancing valve can be replaced by a hydraulic lock.

[0043] In some implementation cases, the first stroke limit valve 15 and the second stroke limit valve 16 are stop valves whose throttling effect is related to the stroke change of their reversing pressure rods, wherein the first stroke limit valve 15 can realize the function of the first hydraulic cylinder 1 gradually slowing down and finally stopping smoothly and automatically after reaching the specified position during the retraction process, and the second stroke limit valve 16 can realize the function of the second hydraulic cylinder 2 gradually slowing down and finally stopping smoothly and automatically after reaching the specified position during the retraction process. The first stroke limit valve 15 and the second stroke limit valve 16 are respectively installed in a staggered manner with the pressure rod mechanism corresponding to the working device. When the pressure rod mechanism of the working device moves to press the reversing pressure rod of the first stroke limit valve 15 or the second stroke limit valve 16, the first stroke limit valve 15 or the second stroke limit valve 16 gradually switches the working position to make the working device, i.e., the pressure rod mechanism, start to decelerate, thereby making the reversing speed of the reversing pressure rod of the stroke limit valve also decrease accordingly, and finally making the first hydraulic cylinder 1 or the second hydraulic cylinder 2 form a closed-loop control circuit with adaptive speed reduction, and finally the first stroke limit valve 15 or the second stroke limit valve 16 will completely reverse to cut off the working oil circuit, so as to realize the function of the first hydraulic cylinder 1 or the second hydraulic cylinder 2 gradually decelerating and finally stopping smoothly and automatically after reaching the specified position.

[0044] Taking the snow thrower working device as an example, the first and second stroke limit valves 15, 16 can be installed within the slipper mechanism, which is capable of slight vertical movement relative to the entire working device. When the working device is lowered, the slipper mechanism stops upon contact with the ground, but the remaining working device components can continue to descend a short distance. Simultaneously, the working device's pressure rod mechanism begins to contact the reversing pressure rods of the first and / or second stroke limit valves 15, 16. As the device continues to descend, the pressure rods press the reversing pressure rods, gradually reversing the valve cores of the first and / or second stroke limit valves 15, 16. At this point, the oil circuits in the rod chambers of the first and / or second hydraulic cylinders 1 and 2 begin to throttle, slowing the working device's descent. This deceleration gradually increases with the stroke of the reversing pressure rods, ultimately shutting off the oil circuits in the rod chambers of the first and / or second hydraulic cylinders 2. This ensures that the snow thrower working device gradually decelerates and then stops smoothly and automatically after reaching the designated position during descent. This feature enables rapid and accurate positioning of the snow thrower's working device, improving the efficiency and effectiveness of the snow removal work of the snow thrower, while significantly reducing the impact of the working device's movement, improving the safety of the equipment and the comfort of the operator.

[0045] In some implementation cases, the first one-way speed regulating valve 7, the second one-way speed regulating valve 8, the third one-way speed regulating valve 9, and the fourth one-way speed regulating valve 10 are one-way throttle valves with pressure compensation and adjustable valve opening size. This feature ensures that the flow rate output by the one-way speed regulating valve is independent of the load size and is only related to the size of the valve opening. That is, the flow rate output by the one-way speed regulating valve is not affected by load changes after adjustment. According to the above solution, the first one-way speed regulating valve 7 can control the extension speed of the first hydraulic cylinder 1, the second one-way speed regulating valve 8 can control the retraction speed of the first hydraulic cylinder 1, the third one-way speed regulating valve 9 can control the extension speed of the second hydraulic cylinder 2, and the fourth one-way speed regulating valve 10 can control the retraction speed of the second hydraulic cylinder 2.

[0046] According to the above embodiment, the precision of the synchronized extension and retraction motion of the first and second hydraulic cylinders 1 and 2 can be adjusted by adjusting the first, second, third, and fourth one-way speed regulating valves 7, 8, 9, and 10. For example, if the extension speeds of the first and second hydraulic cylinders 1 and 2 of the snow thrower's working device are inconsistent, the precision of their synchronized extension motion can be adjusted by manually adjusting the first or third one-way speed regulating valve 7 or 9. If the retraction speeds of the first and second hydraulic cylinders 1 and 2 of the working device are inconsistent, the precision of their synchronized retraction motion can be adjusted by manually adjusting the second or fourth one-way speed regulating valve 8 or 10. If the overall extension motion of the first and second hydraulic cylinders 1 and 2 of the working device is too slow or too fast, the extension speeds of the first and second hydraulic cylinders 1 and 2 can be synchronized by simultaneously adjusting the first and third one-way speed regulating valves 7 and 9. When the overall retraction of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 of the working device is too slow or too fast, the retraction speeds of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 can be synchronously adjusted by simultaneously adjusting the second one-way speed regulating valve 8 and the fourth one-way speed regulating valve 10. According to the above control method, the two hydraulic cylinders can be synchronized during the raising and lowering of the working device of the snow thrower. The movement speeds of the two hydraulic cylinders or the overall movement speed of the working device can be adjusted according to actual working conditions, thereby improving the accuracy of the synchronized movement of the two hydraulic cylinders of the working device of the snow thrower and the working efficiency of the equipment.

[0047] In some implementation cases, the first three-position four-way electrically controlled directional valve 17 and the second three-position four-way electrically controlled directional valve 18 are electrically controlled, and can realize simultaneous or independent movement of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 by means of electrical signal control. For example, when the first hydraulic cylinder 1 and the second hydraulic cylinder 2 need to move simultaneously, the first three-position four-way electrically controlled directional valve 17 and the second three-position four-way electrically controlled directional valve 18 can be controlled by electrical signals to be energized at the same working position at the same time, and at this time, the first hydraulic cylinder 1 and the second hydraulic cylinder 2 extend or retract simultaneously. When the first hydraulic cylinder 1 or the second hydraulic cylinder 2 needs to move individually, the corresponding first three-position four-way electrically controlled directional valve 17 or the second three-position four-way electrically controlled directional valve 18 can be controlled by electrical signals to be energized, and at this time, only one hydraulic cylinder maintains the extension or retraction action. According to the above control logic, the first hydraulic cylinder 1 and the second hydraulic cylinder 2 can be realized to move simultaneously or independently.

[0048] In summary, the adaptive positioning hydraulic system for the working device provided in the embodiment of the present application can realize the function of gradually slowing down the working device of the snow thrower and finally stopping smoothly and automatically after reaching the designated position, which can help the working device of the snow thrower to achieve fast and accurate positioning, improve the snow removal efficiency and snow removal effect of the snow thrower, and at the same time significantly reduce the movement impact of the working device, improve the safety of the equipment and the comfort of operation. In addition, the hydraulic system can also realize the synchronous action and individual action of the two hydraulic cylinders of the working device, and can adjust the speed of each hydraulic cylinder or the overall movement speed of the working device according to the actual working conditions, thereby improving the accuracy and work efficiency of the synchronous action of the two hydraulic cylinders of the working device. In general, the control scheme of the hydraulic system is highly functional and has diversified operations. At the same time, the structural composition is simple, the economic cost is low, and the debugging method is also simple and convenient. In addition, the movement direction of the working device can be vertical or horizontal, which is not limited here.

[0049] Another preferred embodiment of the present application further provides an engineering machine, comprising the aforementioned working device adaptive positioning hydraulic system.

[0050] Another preferred embodiment of the present application further provides a snow thrower, comprising the aforementioned working device adaptive positioning hydraulic system.

[0051] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0052] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A working device adaptive positioning hydraulic system, characterized in that: include: At least two sets of hydraulic drive branches are arranged in parallel, the oil inlets of the hydraulic drive branches are connected to the oil outlets of the hydraulic pumps, and the oil return ports are connected to the hydraulic oil tanks. Each set of hydraulic drive branches includes a three-position four-way electrically controlled reversing valve, a stroke limit valve, a two-position three-way hydraulically controlled reversing valve, two one-way speed regulating valves, a hydraulic cylinder, and a damper, wherein: The A port of the three-position four-way electrically controlled reversing valve is connected in sequence to one of the one-way speed regulating valves and the rodless chamber of the hydraulic cylinder through a pipeline, the B port of the three-position four-way electrically controlled reversing valve is connected to the oil inlet of the stroke limit valve, the oil outlet of the stroke limit valve is connected to the P port and the control oil port of the two-position three-way hydraulically controlled reversing valve, the A port of the two-position three-way hydraulically controlled reversing valve is connected in sequence to another one-way speed regulating valve and the rod chamber of the hydraulic cylinder through a pipeline, and the T port of the two-position three-way hydraulically controlled reversing valve is connected to the hydraulic oil tank; One end of the damper is connected to the control oil port of the two-position three-way hydraulically controlled reversing valve and the B port of the three-position four-way electrically controlled reversing valve, and the other end of the damper is connected to the T port of the two-position three-way hydraulically controlled reversing valve; When the hydraulic cylinder has a rod cavity, oil flows into the P port and the A port of the two-position three-way hydraulic control reversing valve, and the T port is cut off. When the hydraulic cylinder has no rod cavity, oil flows into the A port and the T port of the two-position three-way hydraulic control reversing valve, and the P port is cut off. The stroke limit valve is a two-position, two-way valve. The reversing pressure rod of the stroke limit valve is arranged relative to the pressure rod mechanism corresponding to the working device. When the pressure rod mechanism moves to press the reversing pressure rod of the stroke limit valve, the stroke limit valve gradually switches the working position to make the working device start to slow down, thereby making the reversing speed of the reversing pressure rod of the stroke limit valve also decrease accordingly, and finally the hydraulic cylinder forms a closed-loop control circuit with adaptive speed reduction, and finally the stroke limit valve will completely reverse to cut off the working oil circuit, so that the hydraulic cylinder will gradually slow down and finally stop smoothly and automatically after reaching the specified position.

2. The self-adaptive positioning hydraulic system for a working device according to claim 1, characterized in that: A balancing valve is provided between the rodless cavity of the hydraulic cylinder and the connected one-way speed regulating valve, and between the rod cavity of the hydraulic cylinder and the connected one-way speed regulating valve.

3. The self-adaptive positioning hydraulic system for a working device according to claim 1, characterized in that: A hydraulic lock is provided between the rodless cavity of the hydraulic cylinder and the one-way speed regulating valve connected thereto, and between the rod cavity of the hydraulic cylinder and the one-way speed regulating valve connected thereto.

4. The self-adaptive positioning hydraulic system for a working device according to claim 1, characterized in that: The three-position four-way electrically controlled directional control valve adopts a Y-type mid-position function electromagnetic directional control valve.

5. The self-adaptive positioning hydraulic system for a working device according to any one of claims 1 to 4, characterized in that: A safety valve is provided between the oil outlet of the hydraulic pump and the hydraulic oil tank.

6. An engineering machine, characterized in that: The method comprises the adaptive positioning hydraulic system for a working device according to any one of claims 1 to 4.

7. A snow thrower, characterized in that: The method comprises the adaptive positioning hydraulic system for a working device according to any one of claims 1 to 4.

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