An electric proportional load-sensing multi-way valve for industrial vehicles

Abstract

The present invention relates to the field of electromagnetic valve technology, and specifically to an electric proportional load-sensitive multi-way valve used in industrial vehicles, comprising a lifting link, a reversing link and a tail link, wherein a reversing link is installed on one side of the lifting link, and the lifting link and the reversing link are internally connected, and a tail link is installed on the other side of the lifting link, and the tail link and the lifting link are internally connected, and the lifting and lowering of the load are controlled by electric proportional precise adjustment, and the flow accuracy is high. An electric proportional control module is configured, and the valve has fast response, small hysteresis, and is green and energy-saving. At the same time, a filtering structure is installed on the traditional valve, which can automatically filter, adsorb and remove impurities from the hydraulic oil returning to the oil tank, thereby ensuring the cleanliness of the hydraulic oil and avoiding the problem that the oil in the oil tank enters the valve again through the oil pump, causing the valve to be severely worn and unable to work normally.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic valves, in particular to an electric proportional load-sensitive multi-way valve used in industrial vehicles. Background Art

[0002] In the field of industrial vehicles, especially the forklift industry, which is mainly engaged in logistics and handling, the trend of intelligentization, unmanned operation and electrification is becoming increasingly obvious. The forklift industry is undergoing technological innovation and market changes. On the one hand, the development trend of the industry is developing towards intelligence and unmanned operation. Among them, the technology of forklift mobile robots has gradually matured and has begun to be used in warehousing, logistics and other industries. At the same time, as an important equipment in the industrial field, the improvement and optimization of the performance of forklifts are of great significance to improving work efficiency and reducing costs. With the help of emerging technologies such as 5G and the Internet of Things, the functions of forklift mobile robots in safety identification and intelligent decision-making will be more perfect, and the handling efficiency will also be improved. With more and more attention paid to environmental protection, the trend of replacing new energy products will continue, and the proportion of electric forklifts is expected to remain at a high level. The hydraulic system of the forklift is its core component, which is responsible for realizing the key operating functions such as the lifting and lowering of the fork arm and the lifting and lowering of the goods. This system works through hydraulic transmission to ensure that the forklift can complete various work tasks efficiently and safely. Therefore, the intelligence, electrification and unmanned operation of the forklift require a more intelligent electronic control hydraulic system. The application of electric proportional load valve is an important symbol of the advancement of forklift technology. It not only improves the performance of forklifts, but also makes them more adaptable to the needs of modern logistics.

[0003] However, during the long-term use of the existing electric proportional load valve, its internal parts will naturally wear and produce wear particles to form debris. Most of these debris contain iron components, which will drive the iron chips into the oil tank when the oil flows back. The traditional valve lacks a filtration system, which causes the oil in the oil tank to enter the valve again through the oil pump, which will not only aggravate the wear of its internal parts and reduce the tightness of its parts matching, thereby affecting its response accuracy and response efficiency; in addition, it will also cause the internal parts of the valve to get stuck, resulting in the valve being unable to be used normally, thereby affecting the control performance of the forklift. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an electric proportional load-sensitive multi-way valve for industrial vehicles, which controls the lifting and lowering of the load through electric proportional precise adjustment, has high flow accuracy, is equipped with an electric proportional control module, has fast response, small hysteresis, and is green and energy-saving. At the same time, a filtering structure is installed on the traditional valve, which can automatically filter, adsorb and remove impurities from the hydraulic oil returning to the oil tank, thereby ensuring the cleanliness of the hydraulic oil and avoiding the problem that the oil in the oil tank enters the inside of the valve again through the oil pump, causing severe wear and tear of the valve and inability to work normally.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: an electric proportional load-sensitive multi-way valve applied to industrial vehicles, comprising a lifting link, a reversing link and a tail link, wherein a reversing link is installed on one side of the lifting link, and the lifting link and the reversing link are internally connected, and a tail link is installed on the other side of the lifting link, and the tail link and the lifting link are internally connected;

[0006] An oil inlet is provided on the end surface of the lifting joint, a load oil port 1 is provided on the side of the oil inlet, and an oil return port is provided on one side of the oil inlet and the load oil port;

[0007] The tail joint includes a filter cartridge, a filter cartridge is installed on the side of the lifting joint away from the reversing joint, a return oil pipe is sealed and connected to the return oil port, the end of the return oil pipe is connected to the inside of the filter cartridge, a filter assembly is arranged inside the filter cartridge, an oil outlet pipe is installed on the side wall of the filter cartridge away from the return oil pipe, and the end of the oil outlet pipe away from the filter cartridge is connected to the inside of the oil tank.

[0008] Preferably, the lifting link includes a lifting valve body, the lifting valve body is fixedly connected to the side of the reversing link, a lifting proportional solenoid valve is installed on one side of the lower end of the lifting valve body, a load holding valve is installed on the symmetrical side of the lifting proportional solenoid valve, an LS pressure limiting protection valve is installed on one side of the load holding valve, a descent proportional solenoid valve is installed on the other side of the load holding valve, and an emergency descent stop valve is installed on the side wall of the lifting valve body away from the LS pressure limiting protection valve.

[0009] Preferably, an oil passage 1 is provided inside the lifting valve body, and the oil passage 1 is connected to the oil inlet; an oil passage 2 is provided on one side of the oil passage, and the oil passage 2 is connected to the load oil port 1; an oil passage 3 is provided on the side of the oil passage 2, and the oil passage 3 is connected to the oil return port; the lower end of the oil passage 3 is forked; the lower ends of one side of the oil passage 3 are respectively provided with oil passage 4, oil passage 5 and oil passage 6 which are interconnected; an oil passage 7 is provided on the side of the lower end of the other side of the oil passage 3, and the side of the oil passage 7 is connected to the oil passage 8; the lifting valve body corresponding to the LS pressure limiting protection valve is also provided with oil passage 9, oil passage 1 and oil passage 11 which are interconnected.

[0010] Preferably, a pressure-regulating nut is fixedly installed at the end of oil passage five, a No. 1 pressure-regulating spring is arranged on the side of the pressure-regulating nut, a first two-way pressure compensator is slidably arranged in oil passage three and oil passage four, the first two-way pressure compensator extends into oil passage six and a screw plug is fixedly arranged at the end of oil passage six, a three-way pressure compensator is arranged in oil passage seven, a buffer check valve is arranged inside the three-way pressure compensator, the end of the buffer check valve extends into oil passage eight, a screw plug is fixedly arranged at the end of oil passage eight, the end of the three-way pressure compensator extends into oil passage three and abuts against a No. 2 pressure-regulating spring, the end of the No. 2 pressure-regulating spring away from the three-way pressure compensator abuts against the pressure-regulating nut, and the pressure-regulating nut is fixedly installed at the end of oil passage three.

[0011] Preferably, the reversing link includes a reversing link valve body, a reversing link valve body is installed on the side of the lifting link, a load oil port is arranged on the upper end of the reversing link valve body, a balancing valve block is installed on the side of the reversing link valve body away from the lifting link, a balancing valve is arranged below the reversing link valve body, and a reversing valve is installed below the balancing valve.

[0012] Preferably, an oil passage 12 and an oil passage 13 are provided inside the upper side of the reversing valve body, an oil passage 13 is connected to an oil passage 14 below the oil passage 13, an oil passage 15 is connected to an oil passage 14 below the oil passage 14, a support spring is provided in the oil passage 15, and a second two-way pressure compensator is provided above the support spring.

[0013] Preferably, oil passage 16 and oil passage 17 are symmetrically opened in the middle of the connection between the reversing valve body and the reversing valve, oil passage 16 is connected below oil passage 18, oil passage 17 is connected below oil passage 19, and oil passage 18 and oil passage 19 are connected to form oil passage 20.

[0014] Preferably, the filter assembly includes a rubber ring, which is fixedly installed on the inner wall of the filter cartridge near the oil return pipe, a filter dish is clamped in the middle of the rubber ring, the side wall of the filter dish is porous, the bottom is solid and a circular through groove is opened in the middle, a spherical shell is fixedly connected to the circular through groove, an oil leakage pipe is fixedly installed at the connection between the oil return pipe and the filter cartridge, the end of the oil leakage pipe extends to a position close to the inner wall of the spherical shell, the side wall of the oil leakage pipe located in the circular through groove is an arc-shaped structure, an annular magnet is fixedly installed on the bottom of the filter dish, an enclosure is provided on the inner side of the annular magnet near the edge of the circular through groove, and an oil guide platform is fixedly installed on the oil leakage pipe inside the enclosure.

[0015] Preferably, the side wall of the oil guide platform away from the oil leakage pipe is in an arc-shaped structure and its concave arc surface faces the inner wall of the filter dish.

[0016] Preferably, the cross-section of the enclosure is triangular and its height is greater than the height of the annular magnet.

[0017] Beneficial effects of the present invention:

[0018] 1. The present invention provides an electric proportional load-sensitive multi-way valve for industrial vehicles, which can realize a load-independent flow distribution system and has a lower control pressure difference, thereby realizing green and environmentally friendly operation of the system, fast response, and small hysteresis. In addition, it also has a load compensation function, which can realize flow resistance to load fluctuations.

[0019] 2. The present invention provides an electric proportional load-sensitive multi-way valve for industrial vehicles. The filter assembly can utilize the impact force of the hydraulic oil to drive the filter dish to vibrate continuously, thereby accelerating the filtering efficiency. A spherical shell, an oil guide platform and a baffle are arranged at the bottom of the filter dish, which can not only guide the hydraulic oil to a certain extent, but also prevent debris from flowing back and clogging the return oil pipe. As a result, after the oil in the oil tank enters the valve again through the oil pump, the wear of its internal components will not be aggravated, thereby ensuring the tight performance of the valve components, thereby improving its response accuracy and response efficiency, and further ensuring the control performance of the forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 is a top view of the present invention;

[0022] Figure 2 It is a schematic diagram of the top view of the lifting joint in the present invention;

[0023] Figure 3 It is a schematic diagram of the top view of the structure of the poppet valve body after being cut away in the present invention;

[0024] Figure 4 It is a schematic diagram of the structure of oil passage 9, oil passage 1 and oil passage 11 in the present invention inside the lift valve body;

[0025] Figure 5 It is a front view of the reversing link in the present invention;

[0026] Figure 6 The present invention Figure 5 A schematic cross-sectional structure diagram of ;

[0027] Figure 7 It is a front view structural schematic diagram of the cross-section of the reversing joint valve body in the present invention;

[0028] Figure 8 It is a schematic diagram of the three-dimensional structure of the tail link in the present invention;

[0029] Fig. 9 The present invention Figure 8 A schematic diagram of a cross-sectional three-dimensional structure;

[0030] Fig.10 It is the hydraulic principle diagram of the present invention.

[0031] In the figure:

[0032] 1. Enhance the alliance;

[0033] 11. Lifting valve body; 111. Pressure regulating nut; 112. No. 1 pressure regulating spring; 113. No. 1 two-way pressure compensator; 114. Screw plug; 115. Three-way pressure compensator; 116. Buffer check valve; 117. No. 2 pressure regulating spring;

[0034] 12. Lifting proportional solenoid valve; 13. Emergency lowering stop valve; 14. Lowering proportional solenoid valve; 15. LS pressure limiting protection valve; 16. Load holding valve;

[0035] 2. Reversing joint;

[0036] 21. reversing valve body; 211. supporting spring; 212. second two-way pressure compensator; 22. reversing valve; 23. balancing valve; 24. balancing valve block;

[0037] 3. The last link;

[0038] 31. Filter cartridge; 32. Oil return pipe;

[0039] 33. Filter assembly; 331. Rubber ring; 332. Filter dish; 333. Spherical shell; 334. Oil leakage pipe; 335. Oil guide platform; 336. Ring magnet; 337. Enclosure;

[0040] 34. Oil outlet pipe;

[0041] 4. Oil inlet; 5. Load oil port 1; 6. Oil return port; 7. Load oil port 2;

[0042] 81, oil channel one; 82, oil channel two; 83, oil channel three; 84, oil channel four; 85, oil channel five; 86, oil channel six; 87, oil channel seven; 88, oil channel eight; 89, oil channel nine; 810, oil channel ten; 811, oil channel eleven; 812, oil channel twelve; 813, oil channel thirteen; 814, oil channel fourteen; 815, oil channel fifteen; 816, oil channel sixteen; 817, oil channel seventeen; 818, oil channel eighteen; 819, oil channel nineteen; 820, oil channel twenty. DETAILED DESCRIPTION

[0043] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0044] Embodiment 1:

[0045] See also Figures 1 to 7 as well as Fig.10An electric proportional load-sensitive multi-way valve used in industrial vehicles comprises a lifting link 1 and a reversing link 2. The reversing link 2 is installed on one side of the lifting link 1. The lifting link 1 and the reversing link 2 are internally connected. An oil inlet 4 is provided on the end surface of the lifting link 1. A load oil port 5 is provided on the side of the oil inlet 4. An oil return port 6 is provided on the sides of the oil inlet 4 and the load oil port 5.

[0046] The lifting link 1 includes a lifting valve body 11, and the lifting valve body 11 is fixedly connected to the side of the reversing link 2, a lifting proportional solenoid valve 12 is installed on one side of the lower end of the lifting valve body 11, a load holding valve 16 is installed on the symmetrical side of the lifting proportional solenoid valve 12, an LS pressure limiting protection valve 15 is installed on one side of the load holding valve 16, and a descending proportional solenoid valve 14 is installed on the other side of the load holding valve 16, and an emergency descending stop valve 13 is installed on the side wall of the lifting valve body 11 away from the LS pressure limiting protection valve 15.

[0047] An oil passage 81 is provided inside the lifting valve body 11, and the oil passage 81 is connected to the oil inlet 4. An oil passage 2 82 is provided on the side of the oil passage 81, and the oil passage 2 82 is connected to the load oil port 1 5. An oil passage 3 83 is provided on the side of the oil passage 2 82, and the oil passage 3 83 is connected to the oil return port 6. The lower end of the oil passage 3 83 is forked. The lower ends of one side of the oil passage 3 83 are respectively provided with oil passage 4 84, oil passage 5 85 and oil passage 6 86 that are interconnected. An oil passage 7 87 is provided on the side of the lower end of the other side of the oil passage 3 83, and the side of the oil passage 7 87 is connected to the oil passage 8 88. The lifting valve body 11 corresponding to the LS pressure limiting protection valve 15 is also provided with oil passage 9 89, oil passage 10 810 and oil passage 11 811 that are interconnected.

[0048] A pressure regulating nut 111 is fixedly installed at the end of the oil passage five 85, and a No. 1 pressure regulating spring 112 is arranged on the side of the pressure regulating nut 111. A first two-way pressure compensator 113 is slidably arranged in the oil passage three 83 and the oil passage four 84, the first two-way pressure compensator 113 extends into the oil passage six 86 and a screw plug 114 is fixedly arranged at the end of the oil passage six 86, a three-way pressure compensator 115 is arranged in the oil passage seven 87, a buffer check valve 116 is arranged inside the three-way pressure compensator 115, the end of the buffer check valve 116 extends into the oil passage eight 88, and a screw plug 114 is fixedly arranged at the end of the oil passage eight 88, the end of the three-way pressure compensator 115 extends into the oil passage three 83 and abuts against a No. 2 pressure regulating spring 117, the end of the No. 2 pressure regulating spring 117 away from the three-way pressure compensator 115 abuts against the pressure regulating nut 111, and the pressure regulating nut 111 is fixedly installed at the end of the oil passage three 83.

[0049] The reversing link 2 includes a reversing link valve body 21, which is installed on the side of the lifting link 1. A load oil port 27 is arranged on the upper end of the reversing link valve body 21. A balancing valve block 24 is installed on the side of the reversing link valve body 21 away from the lifting link 1. A balancing valve 23 is arranged below the reversing link valve body 21, and a reversing valve 22 is installed below the balancing valve 23.

[0050] An oil passage 12 812 and an oil passage 13 813 are provided inside the upper side of the reversing valve body 21. The oil passage 13 813 is connected to the oil passage 14 814 below. The oil passage 14 814 is connected to the oil passage 15 815 below. A support spring 211 is provided in the oil passage 15 815. A second two-way pressure compensator 212 is provided above the support spring 211.

[0051] The oil passage 16 816 and the oil passage 17 817 are symmetrically opened in the middle of the connection between the reversing valve body 21 and the reversing valve 22. The oil passage 16 816 is connected to the oil passage 18 818 below, and the oil passage 17 817 is connected to the oil passage 19 819 below. The oil passage 18 818 and the oil passage 19 819 are connected to form the oil passage 20 820.

[0052] During specific operation, when the load oil port 15 is not working, the hydraulic oil enters the oil passage 181 through the oil inlet 4, and then enters the right side of the three-way pressure compensator 115 through the oil passage 88, so that the three-way pressure compensator 115 overcomes the second pressure regulating spring 117 and moves to the left, and then the oil in the oil inlet 4 returns to the oil return port 6 through the oil passage 383. At this time, a pressure difference is formed in the chambers on both sides of the three-way pressure compensator 115, so that the oil inlet 4 can be unloaded at a lower pressure. The buffer check valve 116 arranged inside the three-way pressure compensator 115 can ensure the smooth movement of the three-way pressure compensator 115, thereby accurately adjusting the flow rate and working in an energy-saving and efficient manner;

[0053] When the load oil port 15 is lifted, a part of the hydraulic oil enters the lifting proportional solenoid valve 12 through the oil inlet 4, and then enters the load oil port 15 through the oil channel 1 81, the load holding valve 16 and the oil channel 2 82. At the same time, another part of the hydraulic oil from the oil inlet 4 enters the oil channel 88 through the oil channel 1 81 and the buffer check valve 116, and establishes pressure on the right side of the three-way pressure compensator 115. In addition, the hydraulic oil pressure of the load oil port 15 is fed back to the left side of the three-way pressure compensator 115 to establish a load feedback pressure. At this time, a pressure balance is formed on the left and right sides of the three-way pressure compensator 115. No matter how the pressure at the load oil port 15 changes, under the regulation of the three-way pressure compensator 115, the pressure difference at both ends of the lifting proportional solenoid valve 12 always remains balanced. As the flow changes, the valve core of the lifting proportional solenoid valve 12 begins to change linearly and continuously, and the flow and the current acting on the coil form a proportional relationship. The excess hydraulic oil is unloaded through the lifting proportional solenoid valve 12. Due to the negative feedback regulation of the three-way pressure compensator 115, the change in pressure at the load oil port 15 will not affect the flow regulation control, so that the lifting of the load oil port 15 can move continuously and smoothly. In addition to being fed back to the three-way pressure compensator 115, the load pressure at the load oil port 15 can also be fed back to the LS pressure limiting protection valve 15 through the oil passage 989 and the oil passage 11811, thereby avoiding the phenomenon of overload operation and ensuring the safe operation of the system. When the lifting of the load oil port 15 stops, due to the existence of the load holding valve 16, the pressure at the load oil port 15 remains constant, and the load can be locked for a long time to ensure the stability and safety of the vehicle;

[0054] When the load oil port 15 is working downward, the oil at the oil inlet 4 is unloaded to the return oil port 6 through the oil channel 3 83. At this time, the descending proportional solenoid valve 14 is energized, so that the hydraulic oil of the load oil port 15 passes through the oil channel 2 82, the descending proportional solenoid valve 14 and the oil channel 4 84 to enter the oil channel 5 85, that is, the spring side of the first two-way pressure compensator 113. Since a No. 1 pressure regulating spring 112 is installed in the cavity on this side, part of the hydraulic oil of the load oil port 15 will enter the non-spring side of the first two-way pressure compensator 113 through the oil channel 6 86, so that a control pressure difference is formed on both sides of the first two-way pressure compensator 113. Without considering the hydraulic force, the pressure difference will only be determined by the reaction force of the No. 1 pressure regulating spring 112. As the coil current of the descending proportional solenoid valve 14 changes, the flow through the descending proportional solenoid valve 14 will also change linearly and stably. Under the pressure feedback regulation of the first two-way pressure compensator 113, the flow of the corresponding current is constant and will not change with the change of the load pressure of the load oil port 15. Therefore, when the load is reduced, it is stable and shock-free. The emergency descending stop valve 13 is normally closed when not working. When the descending proportional solenoid valve 14 cannot work, the opening of the emergency descending stop valve 13 can be adjusted to allow the load to return oil through the bypass oil circuit to unload;

[0055] When the direction needs to be changed, the hydraulic oil at the oil inlet 4 passes through the oil passage 12 812, the second two-way pressure compensator 212 and the oil passage 14 814 and enters the valve stem. At this time, the coil of the reversing valve 22 is energized and drives its valve core to move. At this time, the hydraulic oil at the oil inlet 4 enters the oil passage 16 816 through the oil passage 14 814 and then enters the load oil port 27. At the same time, the pressure of the load oil port 27 is fed back to the spring chamber of the second two-way pressure compensator 212 through the oil passage 20 820 and the oil passage 15 815. The pressure difference between the upper and lower ends of the second two-way pressure compensator 212 is the pressure difference between the inlet and outlet oil ends of its valve stem. When the valve stem of the reversing valve 22 moves to the position under the corresponding current, the flow through its valve stem is fixed, and the flow will not change with the change of load.

[0056] Embodiment 2:

[0057] The technical solution is basically the same as that of the first embodiment, see Figure 1 , Figure 8 and Fig. 9 The difference is that: the electric proportional load-sensitive multi-way valve used for industrial vehicles also includes a tail link 3, and the tail link 3 is installed on the side of the lifting link 1 away from the reversing link 2, and the tail link 3 is internally connected to the lifting link 1.

[0058] The tail link 3 includes a filter cartridge 31, the filter cartridge 31 is installed on the side of the lifting link 1 away from the reversing link 2, a return oil pipe 32 is sealed and connected to the oil return port 6, the end of the return oil pipe 32 is connected to the inside of the filter cartridge 31, a filter assembly 33 is arranged inside the filter cartridge 31, an oil outlet pipe 34 is installed on the side wall of the filter cartridge 31 away from the return oil pipe 32, and the end of the oil outlet pipe 34 away from the filter cartridge 31 is connected to the inside of the oil tank.

[0059] The filter assembly 33 includes a rubber ring 331, and the rubber ring 331 is fixedly installed at the position of the inner wall of the filter cartridge 31 near the oil return pipe 32. A filter dish 332 is clamped in the middle of the rubber ring 331. The filter dish 332 has a porous side wall and a solid bottom with a circular through groove in the middle. A spherical shell 333 is fixedly connected to the circular through groove. An oil leakage pipe 334 is fixedly installed at the connection between the oil return pipe 32 and the filter cartridge 31. The end of the oil leakage pipe 334 extends to a position close to the inner wall of the spherical shell 333. The side wall of the oil leakage pipe 334 located in the circular groove has an arc-shaped structure, and an annular magnet 336 is fixedly installed at the bottom of the filter dish 332. A baffle 337 is arranged on the inner side of the annular magnet 336 near the edge of the circular groove, and an oil guide platform 335 is fixedly installed on the oil leakage pipe 334 inside the baffle 337. The side wall of the oil guide platform 335 away from the oil leakage pipe 334 has an arc-shaped structure and its concave arc surface faces the inner wall of the filter dish 332. The cross-section of the baffle 337 is triangular and its height is greater than the height of the annular magnet 336.

[0060] During specific operation, the hydraulic oil flowing out through the oil return port 6 will enter the spherical shell 333 through the oil return pipe 32 and the oil leakage pipe 334. At this time, the hydraulic oil can bring out the debris of natural wear inside the electric proportional load-sensitive multi-way valve and impact the spherical shell 333 with the oil. The impact force can drive the filter dish 332 to vibrate continuously to ensure the filtering efficiency. At the same time, the debris will be discharged through the circular groove and the arc of the side wall of the oil leakage pipe 334 under the action of the impact oil, and flow to the inner wall of the filter dish 332 under the guidance of the arc side wall of the oil guide platform 335. At this time, the hydraulic oil can smoothly enter the bottom of the filter dish 332 and enter the oil outlet pipe The hydraulic oil will flow back to the oil tank under the action of 34, while the debris in the hydraulic oil will be blocked by the filter dish 332 and slide down along its inner wall, and finally be absorbed on the outside of the annular magnet 336. When the flow of hydraulic oil sliding down the filter dish 332 is large, the hydraulic oil will inevitably drive some debris to move to the inside of the annular magnet 336. At this time, the enclosure 337 can block it and make the part of the hydraulic oil flow to the inside of the annular magnet 336, and the debris in the hydraulic oil will be absorbed on the inner wall of the annular magnet 336. In this way, the cleanliness of the hydraulic oil flowing back to the oil tank can be guaranteed, and the normal use of the electric proportional load-sensitive multi-way valve can be guaranteed in the future.

[0061] The working principle of the present invention when in use:

[0062] 1: The electric proportional load-sensitive multi-way valve used for industrial vehicles is installed normally by manual operation to ensure that it can be used normally. During use, when the load oil port 15 is not working, the hydraulic oil enters the oil channel 181 through the oil inlet 4, and then enters the right side of the three-way pressure compensator 115 through the oil channel 88, so that the three-way pressure compensator 115 overcomes the second pressure regulating spring 117 and moves to the left. Then the oil in the oil inlet 4 returns to the oil return port 6 through the oil channel 383. At this time, a pressure difference is formed in the chambers on both sides of the three-way pressure compensator 115, so that the oil inlet 4 can be unloaded at a lower pressure. The buffer check valve 116 arranged inside the three-way pressure compensator 115 can ensure the smooth movement of the three-way pressure compensator 115, thereby accurately adjusting the flow rate and energy-saving and efficient operation.

[0063] 2: When the load oil port 15 is lifted, a part of the hydraulic oil enters the lifting proportional solenoid valve 12 through the oil inlet 4, and then enters the load oil port 15 through the oil channel 1 81, the load holding valve 16 and the oil channel 2 82. At the same time, another part of the hydraulic oil from the oil inlet 4 enters the oil channel 88 through the oil channel 1 81 and the buffer check valve 116, and establishes pressure on the right side of the three-way pressure compensator 115. In addition, the hydraulic oil pressure of the load oil port 15 is fed back to the left side of the three-way pressure compensator 115 to establish a load feedback pressure. At this time, a pressure balance is formed on the left and right sides of the three-way pressure compensator 115. No matter how the pressure at the load oil port 15 changes, under the regulation of the three-way pressure compensator 115, the pressure difference at both ends of the lifting proportional solenoid valve 12 always remains balanced. As the flow changes, the valve core of the lifting proportional solenoid valve 12 begins to change linearly and continuously, and the flow and the current acting on the coil form a proportional relationship. The excess hydraulic oil is unloaded through the lifting proportional solenoid valve 12. Due to the negative feedback regulation of the three-way pressure compensator 115, the change in pressure at the load oil port 15 will not affect the flow regulation control, so that the lifting of the load oil port 15 can move continuously and smoothly. In addition to being fed back to the three-way pressure compensator 115, the load pressure at the load oil port 15 can also be fed back to the LS pressure limiting protection valve 15 through the oil passage 989 and the oil passage 11811, thereby avoiding the phenomenon of overload operation and ensuring the safe operation of the system. When the lifting of the load oil port 15 stops, due to the existence of the load holding valve 16, the pressure at the load oil port 15 remains constant, and the load can be locked for a long time to ensure the stability and safety of the vehicle;

[0064] 3: When the load oil port 15 is working downward, the oil at the oil inlet 4 is unloaded to the return oil port 6 through the oil channel 3 83. At this time, the descending proportional solenoid valve 14 is energized, so that the hydraulic oil of the load oil port 15 passes through the oil channel 2 82, the descending proportional solenoid valve 14 and the oil channel 4 84 to enter the oil channel 5 85, that is, the spring side of the first two-way pressure compensator 113. Since a No. 1 pressure regulating spring 112 is installed in the cavity on this side, part of the hydraulic oil of the load oil port 15 will enter the non-spring side of the first two-way pressure compensator 113 through the oil channel 6 86, so that a control pressure difference is formed on both sides of the first two-way pressure compensator 113. Without considering the hydraulic force, the pressure difference will only be determined by the reaction force of the No. 1 pressure regulating spring 112. As the coil current of the descending proportional solenoid valve 14 changes, the flow through the descending proportional solenoid valve 14 will also change linearly and stably. Under the pressure feedback regulation of the first two-way pressure compensator 113, the flow of the corresponding current is constant and will not change with the change of the load pressure of the load oil port 15. Therefore, when the load is reduced, it is stable and shock-free. The emergency descending stop valve 13 is normally closed when not working. When the descending proportional solenoid valve 14 cannot work, the opening of the emergency descending stop valve 13 can be adjusted to allow the load to return oil through the bypass oil circuit to unload;

[0065] Four: When the direction needs to be changed, the hydraulic oil at the oil inlet 4 passes through the oil passage 12 812, the second two-way pressure compensator 212 and the oil passage 14 814 and enters the valve stem. At this time, the coil of the reversing valve 22 is energized and drives its valve core to move. At this time, the hydraulic oil at the oil inlet 4 passes through the oil passage 14 814 and enters the oil passage 16 816, and then enters the load oil port 27. At the same time, the pressure of the load oil port 27 is fed back to the spring chamber of the second two-way pressure compensator 212 through the oil passage 20 820 and the oil passage 15 815. The pressure difference between the upper and lower ends of the second two-way pressure compensator 212 is the pressure difference between the inlet and outlet oil ends of its valve stem. When the valve stem of the reversing valve 22 moves to the position under the corresponding current, the flow through its valve stem is fixed, and the flow will not change with the change of load;

[0066] Five: During any of the above steps, the hydraulic oil flowing out through the oil return port 6 will enter the spherical shell 333 through the oil return pipe 32 and the oil leakage pipe 334. At this time, the hydraulic oil can bring out the debris of natural wear inside the electric proportional load-sensitive multi-way valve and impact the spherical shell 333 with the oil. The impact force can drive the filter dish 332 to vibrate continuously to ensure the filtering efficiency. At the same time, the debris will be discharged through the circular groove and the arc of the side wall of the oil leakage pipe 334 under the action of the impact oil, and flow to the inner wall of the filter dish 332 under the guidance of the arc side wall of the oil guide platform 335. At this time, the hydraulic oil can smoothly enter the bottom of the filter dish 332 and Under the action of the oil outlet pipe 34, it flows back to the oil tank, and the debris in the hydraulic oil will be blocked by the filter dish 332 and slide down along its inner wall, and finally be adsorbed on the outside of the annular magnet 336. When the flow of hydraulic oil sliding down the filter dish 332 is large, the hydraulic oil will inevitably drive some debris to move to the inside of the annular magnet 336. At this time, the enclosure 337 can block it and make this part of the hydraulic oil flow to the inside of the annular magnet 336, and the debris in the hydraulic oil will be adsorbed on the inner wall of the annular magnet 336. In this way, the cleanliness of the hydraulic oil flowing back to the oil tank can be guaranteed, and the electric proportional load-sensitive multi-way valve can still be used normally in the future.

[0067] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. An electric proportional load-sensitive multi-way valve for industrial vehicles, comprising a lifting link (1), a reversing link (2) and a tail link (3), characterized in that: A reversing link (2) is installed on one side of the lifting link (1), and the lifting link (1) and the reversing link (2) are internally connected. A tail link (3) is installed on the other side of the lifting link (1), and the tail link (3) and the lifting link (1) are internally connected. An oil inlet (4) is provided on the end surface of the lifting link (1), a load oil port 1 (5) is provided on the side of the oil inlet (4), and an oil return port (6) is provided on the side of the oil inlet (4) and the load oil port 1 (5); The tail link (3) comprises: A filter cartridge (31), the filter cartridge (31) being installed on the side of the lifting link (1) away from the reversing link (2); An oil return pipe (32), the oil return port (6) is sealedly connected with the oil return pipe (32), and the end of the oil return pipe (32) is connected to the interior of the filter cartridge (31); A filter assembly (33), wherein the filter cartridge (31) is provided with a filter assembly (33); An oil outlet pipe (34), the oil outlet pipe (34) is installed on the side wall of the filter cartridge (31) away from the oil return pipe (32), and the end of the oil outlet pipe (34) away from the filter cartridge (31) is connected to the inside of the oil tank; The filter assembly (33) comprises a rubber ring (331), the rubber ring (331) being fixedly mounted at a position of the inner wall of the filter cartridge (31) close to the oil return pipe (32), a filter dish (332) being clamped in the middle of the rubber ring (331), the filter dish (332) having a porous side wall and a solid bottom and a circular through groove in the middle, a spherical shell (333) being fixedly connected to the circular through groove, and a connection between the oil return pipe (32) and the filter cartridge (31) being fixedly connected to the spherical shell (333). An oil leakage pipe (334) is fixedly installed, the end of the oil leakage pipe (334) extends to a position close to the inner wall of the spherical shell (333), the side wall of the oil leakage pipe (334) located in the circular through groove is in an arc-shaped structure, an annular magnet (336) is fixedly arranged at the bottom of the filter dish (332), a baffle (337) is arranged on the inner side of the annular magnet (336) near the edge of the circular through groove, and an oil guide platform (335) is fixedly installed on the oil leakage pipe (334) inside the baffle (337); The side wall of the oil guide platform (335) away from the oil leakage pipe (334) is in an arc-shaped structure, and its concave arc surface faces the inner wall of the filter dish (332); The enclosure (337) has a triangular cross-section and a height greater than a height of the annular magnet (336).

2. The electric proportional load-sensing multi-way valve for industrial vehicles according to claim 1, characterized in that: The lifting link (1) comprises a lifting valve body (11), the lifting valve body (11) is fixedly connected to the side of the reversing link (2), a lifting proportional solenoid valve (12) is installed on one side of the lower end of the lifting valve body (11), a load holding valve (16) is installed on the symmetrical side of the lifting proportional solenoid valve (12), an LS pressure limiting protection valve (15) is installed on one side of the load holding valve (16), a descent proportional solenoid valve (14) is installed on the other side of the load holding valve (16), and an emergency descent stop valve (13) is installed on the side wall of the lifting valve body (11) away from the LS pressure limiting protection valve (15).

3. The electric proportional load-sensing multi-way valve for industrial vehicles according to claim 2, characterized in that: The lifting valve body (11) is provided with an oil passage (81) inside, the oil passage (81) being connected to the oil inlet (4), an oil passage (82) being provided on the side of the oil passage (81), the oil passage (82) being connected to the load oil port (5), an oil passage (83) being provided on the side of the oil passage (82), the oil passage (83) being connected to the oil return port (6), the lower end of the oil passage (83) being forked, one of the oil passages (83) Oil passage 4 (84), oil passage 5 (85) and oil passage 6 (86) which are interconnected are respectively arranged on both sides of the lower end of the side, oil passage 7 (87) is arranged on the lower end side of the other side of oil passage 3 (83), and the side of oil passage 7 (87) is connected to oil passage 8 (88), and the inside of the lifting valve body (11) corresponding to the LS pressure limiting protection valve (15) is also provided with oil passage 9 (89), oil passage 10 (810) and oil passage 11 (811) which are interconnected.

4. The electric proportional load-sensing multi-way valve for industrial vehicles according to claim 3, characterized in that: The end of the oil passage 5 (85) is fixedly mounted with a pressure regulating nut (111), and a first pressure regulating spring (112) is arranged on the side of the pressure regulating nut (111). A first two-way pressure compensator (113) is slidably arranged in the oil passage 3 (83) and the oil passage 4 (84). The first two-way pressure compensator (113) extends into the oil passage 6 (86) and a screw plug (114) is fixedly arranged at the end of the oil passage 6 (86). A three-way pressure compensator (115) is arranged in the oil passage 7 (87). The three-way pressure compensator (11 5) A buffer check valve (116) is provided inside, the end of the buffer check valve (116) extends into the oil passage eight (88), the end of the oil passage eight (88) is fixedly provided with a screw plug (114), the end of the three-way pressure compensator (115) extends into the oil passage three (83) and abuts against a second pressure regulating spring (117), the end of the second pressure regulating spring (117) away from the three-way pressure compensator (115) abuts against a pressure regulating nut (111), and the pressure regulating nut (111) is fixedly installed at the end of the oil passage three (83).

5. The electric proportional load-sensing multi-way valve for industrial vehicles according to claim 1, characterized in that: The reversing link (2) comprises a reversing link valve body (21), the reversing link valve body (21) is installed on the side of the lifting link (1), a load oil port 2 (7) is arranged on the upper end of the reversing link valve body (21), a balancing valve block (24) is installed on the side of the reversing link valve body (21) away from the lifting link (1), a balancing valve (23) is arranged below the reversing link valve body (21), and a reversing valve (22) is installed below the balancing valve (23).

6. The electric proportional load-sensing multi-way valve for industrial vehicles according to claim 5, characterized in that: An oil passage 12 (812) and an oil passage 13 (813) are provided inside the upper side of the reversing joint valve body (21); an oil passage 14 (814) is connected below the oil passage 13 (813); an oil passage 15 (815) is connected below the oil passage 14 (814); a support spring (211) is provided inside the oil passage 15 (815); and a second two-way pressure compensator (212) is provided above the support spring (211).

7. The electric proportional load-sensing multi-way valve for industrial vehicles according to claim 6, characterized in that: An oil passage 16 (816) and an oil passage 17 (817) are symmetrically provided in the middle of the connection between the reversing valve body (21) and the reversing valve (22); an oil passage 18 (818) is connected below the oil passage 16 (816); an oil passage 19 (819) is connected below the oil passage 17 (817); and the oil passages 18 (818) and 19 (819) are connected to form an oil passage 20 (820).

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