A high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors

Abstract

This invention belongs to the field of tractor hydraulic technology and discloses a high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors. It includes an oil suction filter, an oil pump, a multi-way valve assembly, a return oil filter, and an oil tank. The oil suction filter is located inside the oil tank, and its outlet is connected to the oil pump's inlet. The oil pump's outlet is connected to the inlet (Pin) of the multi-way valve assembly via a pipe. The return (Tout) of the multi-way valve assembly is connected to the inlet of the return oil filter via a pipe, and the return oil filter's outlet is located inside the oil tank. This invention provides a simple, reliable, and easy-to-operate high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors. It not only meets the driver's requirement to coordinate multiple sets of hydraulic outputs with different needs but also provides the driver with adjustable hydraulic output valves.

Description

Technical Field

[0001] This invention belongs to the field of tractor hydraulic technology, specifically relating to a high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors. Background Technology

[0002] Currently, in the hydraulic lifting systems of various models of large and medium-power wheeled tractors produced domestically, the required single-piece output flow rate of the hydraulic system is increasing, which also places greater demands on the number and type of hydraulic output valves. However, existing tractor hydraulic lifting systems suffer from various defects, such as large leakage at the mid-position of high-flow mechanical lifting valves, excessive static settlement during lifting, lack of priority constant flow output, or lack of simple electronic control operation, making it difficult to meet the increasingly diverse needs of users. Summary of the Invention

[0003] To address the problems existing in the background art, the present invention provides a high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors, comprising an oil suction filter, an oil pump, a multi-way valve assembly, a return oil filter, and an oil tank. The oil suction filter is located inside the oil tank, and the oil outlet of the oil suction filter is connected to the oil inlet of the oil pump. The oil outlet of the oil pump is connected to the oil inlet (Pin) of the multi-way valve assembly via a pipeline. The return oil outlet (Tout) of the multi-way valve assembly is connected to the oil inlet of the return oil filter via a pipeline. The oil outlet of the return oil filter is located inside the oil tank.

[0005] The multi-way valve assembly includes a first section, a second section, a third section, and a fourth section; the oil pump's outlet is connected to a Pin port, which is connected to the internal pipeline of the first section via a P0' port; one end of the first section's return oil pipeline is connected to the inlet of the return oil filter via a T0' port, and the other end is connected to the return oil pipeline of the second section via a T1' port; the first section's outlet oil pipeline is connected to the inlet oil pipeline of the second section via a N1' port; another outlet oil pipeline of the first section is connected to another inlet oil pipeline of the second section via a P1' port; the first section's A1 and B1 ports are connected to external equipment; one end of the second section's return oil pipeline is connected to the inlet of the return oil filter 4 via a T1' port, and the other end is connected to... The return oil line of the third section is connected; the outlet oil line of the second section is connected to the inlet oil line of the third section through port N2'; another outlet oil line of the second section is connected to another inlet oil line of the second section through port P2'; ports A2 and B2 of the second section are connected to external equipment; one end of the return oil line of the third section is connected to the inlet of the return oil filter through port T2', and the other end is connected to the inlet of the fourth section through port T3'; another inlet oil line of the third section is connected to another inlet oil line of the fourth section through port N3'; ports A3 and B3 of the third section are connected to external equipment; ports A4 and B4 of the fourth section are connected to external equipment; ports A5 and B5 are connected to external equipment.

[0006] The first connection includes a safety valve assembly, a flow regulating valve, a variable throttle port, a main valve core, a check valve A, a check valve B, and a trip valve; the main valve core is a four-position seven-way solenoid directional valve; the N port of the main valve core is connected to the P0' port, the safety valve assembly, the flow regulating valve, the variable throttle port, and the trip valve via pipelines; the other end of the safety valve assembly is connected to the return port T0'; the other end of the flow regulating valve is connected to the outlet ports N1' and P1'; the variable throttle port... The other end of the flow port is connected to check valve B, and the other end of check valve B is connected to the P port of the main valve core and the flow regulating valve respectively; the P port of the main valve core is connected to check valve B and the flow regulating valve respectively through pipelines; the T port of the main valve core is connected to the return oil port T0' and T1' respectively through pipelines; the main valve core has three outlets, the first outlet is connected to P1' and N1'; the second outlet is connected to B1; and the third outlet is connected to A1 after passing through check valve A.

[0007] The one-way valve A is a zero-leakage one-way valve.

[0008] The fourth section includes a first reversing valve, a second reversing valve, a third reversing valve, a fourth reversing valve, and a fifth reversing valve;

[0009] The first directional valve has two oil outlets. The first oil outlet is connected to the second and fourth directional valves respectively; the second oil outlet is connected to the third and fifth directional valves respectively; the oil outlet of the second directional valve is connected to port B5; the oil outlet of the fourth directional valve is connected to port B4; the oil outlet of the third directional valve is connected to port A5; and the oil outlet of the fifth directional valve is connected to port A4.

[0010] The first directional valve is a three-position four-way solenoid directional valve, and the neutral position function of the first directional valve is H-shaped.

[0011] The second, third, fourth, and fifth directional control valves are two-position, two-way, zero-leakage solenoid directional control valves.

[0012] The beneficial effects of the present invention are as follows: The present invention provides a high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors. The present invention provides a high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors with simple structure, reliable use and easy operation. It not only meets the driver's requirements for coordinating multiple sets of hydraulic outputs with different needs, but also provides the driver with hydraulic output valves with adjustable flow. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the present invention;

[0014] Figure 2 This is a schematic diagram of the first-line midline principle of the present invention.

[0015] Figure 3 This is a schematic diagram of the first lifting principle of the present invention.

[0016] Figure 4 This is a schematic diagram of the first descent principle of the present invention.

[0017] Figure 5 This is a schematic diagram of the first floating principle of the present invention.

[0018] Figure 6 This is a schematic diagram of the neutral position principle of the electronically controlled valve of the present invention.

[0019] Figure 7 This is a schematic diagram of the lifting principle of the electronically controlled valve of the present invention.

[0020] Figure 8 This is a schematic diagram of the descent principle of the electrically controlled valve of the present invention.

[0021] Figure 9 This is a schematic diagram of the floating principle of the electronically controlled valve of the present invention.

[0022] In the diagram: 1. Suction filter, 2. Oil pump, 3. Multi-way valve assembly, 4. Return filter, 5. Oil tank, 31. First valve, 32. Second valve, 33. Third valve, 34. Fourth valve, 311. Safety valve assembly, 312. Flow control valve, 313. Variable throttle orifice, 314. Main valve core, 315. Check valve A, 316. Check valve B, 317. Trip valve, 341. First directional valve, 342. Second directional valve, 343. Third directional valve, 344. Fourth directional valve, 345. Fifth directional valve. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings: A high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors includes an oil suction filter 1, an oil pump 2, a multi-way valve assembly 3, a return oil filter 4, and an oil tank 5. The oil suction filter 1 is located inside the oil tank 5, and the oil suction port of the oil suction filter 1 is lower than the oil level in the oil tank 5. The oil outlet of the oil suction filter 1 is connected to the oil inlet of the oil pump 2. The oil outlet of the oil pump 2 is connected to the oil inlet Pin port of the multi-way valve assembly 3 through a pipeline. The return oil Tout port of the multi-way valve assembly 3 is connected to the oil inlet of the return oil filter 4 through a pipeline. The oil outlet of the return oil filter 4 is located inside the oil tank 5.

[0025] The multi-way valve assembly 3 includes a first section 31, a second section 32, a third section 33, and a fourth section 34. The oil outlet of the oil pump 2 is connected to a pin port, which is connected to the internal pipeline of the first section 31 via a P0' port. One end of the return oil pipeline of the first section 31 is connected to the inlet of the return oil filter 4 via a T0' port, and the other end is connected to the return oil pipeline of the second section 32 via a T1' port. The oil outlet pipeline of the first section 31 is connected to the inlet pipeline of the second section 32 via a N1' port. Another oil outlet pipeline of the first section 31 is connected to another inlet pipeline of the second section 32 via a P1' port. The A1 and B1 ports of the first section are connected to external equipment. One end of the return oil pipeline of the second section 32 is connected to the inlet of the return oil filter 4 via a T1' port, and the other end is connected via a T2' port. The return oil line of the third section 33 is connected; the outlet oil line of the second section 32 is connected to the inlet oil line of the third section 33 via port N2'; another outlet oil line of the second section 32 is connected to another inlet oil line of the second section 32 via port P2'; ports A2 and B2 of the second section 32 are connected to external equipment; one end of the return oil line of the third section 33 is connected to the inlet of the return oil filter 4 via port T2', and the other end is connected to the inlet of the fourth section 34 via port T3'; another inlet oil line of the third section 33 is connected to another inlet oil line of the fourth section 34 via port N3'; ports A3 and B3 of the third section 33 are connected to external equipment; ports A4 and B4 of the fourth section 34 are connected to external equipment; ports A5 and B5 are connected to external equipment.

[0026] The first valve assembly 31 includes a safety valve assembly 311, a flow regulating valve 312, a variable throttle port 313, a main valve core 314, a check valve A 315, a check valve B 316, and a trip valve 317. The main valve core 314 is a four-position seven-way solenoid directional valve. The N port of the main valve core 314 is connected to the P0' port, the safety valve assembly 311, the flow regulating valve 312, the variable throttle port 313, and the trip valve 317 via pipelines. The other end of the safety valve assembly 311 is connected to the return port T0'. The other end of the flow regulating valve 312 is connected to the outlet port N1' and P1'. The variable throttle port... The other end of port 313 is connected to check valve B316, and the other end of check valve B316 is connected to port P of main valve core 314 and flow regulating valve 312 respectively; port P of main valve core 314 is connected to check valve B316 and flow regulating valve 312 respectively through pipelines; port T of main valve core 314 is connected to return oil port T0't and T1' respectively through pipelines; main valve core 314 has three outlets, the first outlet is connected to port P1' and port N1'; the second outlet is connected to port B1; the third outlet is connected to port A1 after passing through check valve A315, and check valve A315 is a zero-leakage check valve;

[0027] One end of the return oil pipeline of the second section 32 is connected to the oil inlet of the return oil filter 4, and the other end is connected to the return oil pipeline T2' port of the third section 33; the oil outlet P1' port of the second section 32 is connected to the oil inlet P2' port of the third section 33 through a pipeline; the oil outlet N1' port of the second section 32 is connected to the oil inlet N2' port of the third section 33 through a pipeline; the A2 port and B2 port of the second section 32 are connected to external equipment.

[0028] One end of the return oil pipeline of the third section 33 is connected to the oil inlet of the return oil filter 4, and the other end of the return oil pipeline of the third section 33 is connected to the oil inlet T3' of the fourth section 34; the oil outlet N2' of the third section 33 is connected to the oil inlet N3' of the fourth section 34 through a pipeline; the A3 and B3 ports of the third section 33 are connected to external equipment.

[0029] In practical use, when the main valve core 314 is in the neutral position (such as...), Figure 2 As shown in the diagram, the oil from pump 2 enters the first coupling 31 through port P0'. Since port P of the main valve core 314 is not open, the pressure difference across the variable throttle port 313 is zero, so the flow regulating valve 312 is closed. The variable throttle port 313 pushes open the check valve B316, cutting off the oil path to port P. The oil from pump 2 directly reaches port N1' and port P1' through port N of the main valve core 314. At the same time, the hydraulic oil in the jump valve 317 reaches port N1' and port P1' through port N and the internal oil passage of the valve body. The hydraulic oil at port A1 maintains zero leakage under the action of check valve A315.

[0030] When the main valve core 314 is in the raised position (e.g.) Figure 3 As shown in the diagram, the oil from pump 2 enters the first connector 31 through port P0'. One path passes through the variable throttle port 313, pushing open check valve B316 to enter port P of the main valve core 314. The oil then passes through the internal oil passage of the main valve core 314, pushing open check valve A315 to enter port A1. Oil from port B1 flows through the internal oil passage of the main valve core 314 to port T, returning to the return oil tank 5. Since the pressure difference through the variable throttle port 313 is controlled by the flow regulating valve 312, when the pressure difference of the flow regulating valve 312 is constant, the amount of oil entering port A1 is only equal to the pressure difference of the variable throttle port 313. The opening degree of the variable throttle port 313 is related to the oil volume entering port A1. The oil entering port A1 enters the jump valve 317 through the internal oil passage P port of the main valve core 314. When the pressure of port A1 reaches the set jump pressure, the jump valve 317 opens and the main valve core 314 returns to the neutral position. After the oil from the oil pump 2 enters port P0', a portion of the constant flow passes through the variable throttle port 313 and enters port P of the main valve core 314. The excess flow passes through the flow regulating valve 312 and enters ports N1' and P1'.

[0031] When the main valve core 314 is in the lowered position (e.g.) Figure 4As shown in the diagram, after oil from pump 2 passes through port P0', it enters port P of the main valve core 314 through the variable throttle port 313, pushing open check valve B316. It then flows through the internal oil passage of the main valve core 314 into port B1. Simultaneously, due to the movement of the main valve core 314, it opens check valve A315. Oil from port A1 flows through check valve A315 and the internal oil passage of the main valve core 314 to port T0', entering the oil tank 5. Since the pressure difference through the variable throttle port 313 is controlled by the flow regulating valve 312, when the pressure difference of the flow regulating valve 312 is constant, the oil flow rate entering port B1 is only related to the variable throttle port 313. The opening size of the flow port 313 is related to the stability of the oil flow rate entering port B1. The oil from the oil pump 2 enters the jump valve 317 through the N port of the internal oil passage of the main valve core 314. Since the pressure at the N port is the same as the pressure before entering the variable throttle port 313, the jump valve 317 opens when the pressure at the N port reaches the set jump pressure, and the main valve core 314 returns to the neutral position. After the oil from the oil pump 2 enters port P0', a portion of the constant flow rate enters port P of the main valve core 314 through the variable throttle port 313, and the excess flow rate enters ports N1' and P1' through the flow regulating valve 312.

[0032] When the main valve core 314 is in the floating position (e.g.) Figure 5 As shown in the diagram, after oil from oil pump 2 passes through port P0', it pushes open check valve B316 via variable throttle port 313, cutting off the oil passage to port P of main valve core 314; oil from oil pump 2 passes through port N of main valve core 314 into ports P1' and N1'; simultaneously, oil entering jump valve 317 also passes through the internal oil passage of main valve core 314 into ports P1' and N1'; due to the movement of main valve core 314, main valve core 314 pushes open check valve A315; ports A1 and B1 are both connected to port T of main valve core 314, and then flow back to return oil tank 5, achieving a floating effect;

[0033] The second section 32 of the multi-way valve assembly 3 is mechanically operated and is a three-position six-way hydraulic output valve with single / double-acting adjustment; the third section 33 of the multi-way valve assembly 3 is mechanically operated and is a four-position six-way hydraulic output valve with a floating position; since the working principle of these two sets of mechanically operated valves is the same as that of conventional mechanically operated valves, it will not be described in detail.

[0034] The fourth valve 34 has ports A4 and B4 connected to external devices; ports A5 and B5 are also connected to external devices. The fourth valve 34 includes a first directional control valve 341, a second directional control valve 342, a third directional control valve 343, a fourth directional control valve 344, and a fifth directional control valve 345. The first directional control valve 341 is a three-position four-way solenoid directional control valve, and its neutral position function is H-shaped. The second directional control valve 342, the third directional control valve 343, the fourth directional control valve 344, and the fifth directional control valve... Valve 345 is a two-position, two-way, zero-leakage solenoid directional valve; the first directional valve 341 has two oil outlets, the first oil outlet is connected to the second directional valve 342 and the fourth directional valve 344 respectively; the second oil outlet is connected to the third directional valve 343 and the fifth directional valve 345 respectively; the oil outlet of the second directional valve 342 is connected to port B5; the oil outlet of the fourth directional valve 344 is connected to port B4; the oil outlet of the third directional valve 343 is connected to port A5; the oil outlet of the fifth directional valve 345 is connected to port A4.

[0035] In practical use, when the fourth link 34 is in the middle position (e.g.) Figure 6 As shown in the diagram, when DT2 and DT1 of the first directional valve 341 are not energized, and DT3 of the fifth directional valve 345 controlling port A4 and DT4 of the fourth directional valve 344 controlling port B4 are not energized, the oil from the third section 33 is connected to the return port T3' through the first directional valve 341 with the intermediate position function H, and flows back to the oil tank 5 through the internal oil passage. At this time, since DT3 of the fifth directional valve 345 controlling port A4 and DT4 of the fourth directional valve 344 controlling port B4 are not energized, the oil in the A4 chamber is locked by the internal bidirectional check valve of the fifth directional valve 345, and the oil in the B4 chamber is locked by the internal bidirectional check valve of the fourth directional valve 344.

[0036] When the fourth link 34 is in the raised position (e.g.) Figure 7 As shown in the diagram, when DT2, which controls the first directional valve 341, is energized, DT3, which controls the fifth directional valve 345 at port A4, and DT4, which controls the fourth directional valve 344 at port B4, are also energized. At this time, the first directional valve 341 is in the left position when DT2 is energized, and both the fifth directional valve 345 at port A4 and the fourth directional valve 344 at port B4 are in the left position. The oil from the third section 33 enters the left position oil passage of the first directional valve 341 and then enters the left position internal passage of the fifth directional valve 345, which then enters port A4. At the same time, the oil from port B4 enters the left position oil passage of the first directional valve 341 through the left position internal passage of the fourth directional valve 344 and flows back to the oil tank 5 through the internal oil passage.

[0037] When the fourth digit 34 is in a descending position (e.g.) Figure 8As shown in the diagram, when DT1 controlling the first directional valve 341 is energized, DT3 controlling the fifth directional valve 345 at port A4 and DT4 controlling the fourth directional valve 344 at port B4 are also energized. At this time, the first directional valve 341 is in the right position when DT1 is energized, and the fifth directional valve 345 controlling port A4 and the fourth directional valve 344 controlling port B4 are both in the left position. The oil from the third section 33 enters the left position internal passage of the fourth directional valve 344 through the right position oil passage of the first directional valve 341 and enters port B4. At the same time, the oil at port A4 enters the right position internal oil passage of the first directional valve 341 through the left position internal passage of the fifth directional valve 345 and flows back to the oil tank 5 through the internal oil passage.

[0038] When the fourth link 34 is in a floating position, (such as...) Figure 9 As shown in the diagram, when DT1 and DT2 of the first directional valve 341 are not energized, DT3 of the fifth directional valve 345 at port A4 and DT4 of the fourth directional valve 344 at port B4 are energized. At this time, the first directional valve 341 is in the neutral position when DT1 and DT2 are not energized and are energized, and the fifth directional valve 345 at port A4 and the fourth directional valve 344 at port B4 are both in the left position. The oil from the third link 33 flows directly back to the oil tank 5 through the internal oil passage of the first directional valve 341 in the neutral position. The oil at port A4 enters the neutral oil passage of the first directional valve 341 through the internal passage of the fifth directional valve 345 in the left position and flows back to the oil tank 5. The oil at port B4 enters the neutral oil passage of the first directional valve 341 through the internal passage of the fourth directional valve 344 in the left position and flows back to the oil tank 5.

[0039] Since the working principle of the second reversing valve 342 and the third reversing valve 343 is the same as that of the fourth reversing valve 344 and the fifth reversing valve 345, it will not be described again. It is particularly noteworthy that the first reversing valve 341 acts as a bridge in the entire multi-way valve assembly 3. When the first reversing valve 341 is in the neutral position, the oil from the oil pump 2 enters the fourth reversing valve 34 after passing through the first reversing valve 31, the second reversing valve 32 and the third reversing valve 33. After the oil passes through the first reversing valve 341 of the fourth reversing valve 34, it flows directly back to the oil tank 5.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0041] The parts of this invention not described in detail are prior art.

Claims

1. A high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors, comprising an oil suction filter (1), an oil pump (2), a multi-way valve assembly (3), a return oil filter (4), and an oil tank (5), characterized in that: The suction filter (1) is located inside the oil tank (5). The oil outlet of the suction filter (1) is connected to the oil inlet of the oil pump (2). The oil outlet of the oil pump (2) is connected to the oil inlet Pin of the multi-way valve assembly (3) through a pipeline. The return oil Tout of the multi-way valve assembly (3) is connected to the oil inlet of the return oil filter (4) through a pipeline. The oil outlet of the return oil filter (4) is located inside the oil tank (5). The multi-way valve assembly (3) includes a first section (31), a second section (32), a third section (33), and a fourth section (34); the pin port is connected to the internal pipeline of the first section (31) through the P0' port; one end of the return oil pipeline of the first section (31) is connected to the inlet of the return oil filter (4) through the T0' port, and the other end is connected to the return oil pipeline of the second section (32) through the T1' port; the oil outlet pipeline of the first section (31) is connected to the inlet pipeline of the second section (32) through the N1' port; the other oil outlet pipeline of the first section (31) is connected to the other inlet pipeline of the second section (32) through the P1' port; the A1 and B1 ports of the first section are connected to external equipment; one end of the return oil pipeline of the second section (32) is connected to the inlet of the return oil filter (4) through the T1' port, and the other end is connected to the third section (34) through the T2' port. The return oil pipeline of the second section (33) is connected; the oil outlet pipeline of the second section (32) is connected to the oil inlet pipeline of the third section (33) through the N2' port; the other oil outlet pipeline of the second section (32) is connected to the other oil inlet pipeline of the second section (32) through the P2' port; the A2 and B2 ports of the second section (32) are connected to external equipment; one end of the return oil pipeline of the third section (33) is connected to the oil inlet of the return oil filter (4) through the T2' port, and the other end is connected to the oil inlet of the fourth section (34) through the T3' port; the other oil inlet pipeline of the third section (33) is connected to the other oil inlet pipeline of the fourth section (34) through the N3' port; the A3 and B3 ports of the third section (33) are connected to external equipment; the A4 and B4 ports of the fourth section (34) are connected to external equipment; the A5 and B5 ports are connected to external equipment.

2. The high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors according to claim 1, characterized in that: The first connection (31) includes a safety valve assembly (311), a flow regulating valve (312), a variable throttle port (313), a main valve core (314), a check valve A (315), a check valve B (316), and a jump valve (317); the main valve core (314) is a four-position seven-way solenoid directional valve; the N port of the main valve core (314) is connected to the P0' port, the safety valve assembly (311), the flow regulating valve (312), the variable throttle port (313), and the jump valve (317) respectively through pipelines; the other end of the safety valve assembly (311) is connected to the return oil port T0'; the other end of the flow regulating valve (312) is connected to the outlet oil port N1' and... The variable throttle port (313) is connected to port P1'; the other end of the variable throttle port (313) is connected to check valve B (316), and the other end of check valve B (316) is connected to port P of main valve core (314) and flow regulating valve (312) respectively; port P of main valve core (314) is connected to check valve B (316) and flow regulating valve (312) respectively through pipelines; port T of main valve core (314) is connected to return oil port T0' and T1' respectively through pipelines; main valve core (314) has three outlets, the first outlet is connected to port P1' and port N1'; the second outlet is connected to port B1; the third outlet is connected to port A1 after passing through check valve A (315).

3. The high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors according to claim 2, characterized in that: The one-way valve A (315) is a zero-leakage one-way valve.

4. The high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors according to claim 1, characterized in that: The fourth section (34) includes a first directional valve (341), a second directional valve (342), a third directional valve (343), a fourth directional valve (344), and a fifth directional valve (345). The first directional valve (341) has two oil outlets. The first oil outlet is connected to the second directional valve (342) and the fourth directional valve (344) respectively. The second oil outlet is connected to the third directional valve (343) and the fifth directional valve (345) respectively. The oil outlet of the second directional valve (342) is connected to port B5. The oil outlet of the fourth directional valve (344) is connected to port B4. The oil outlet of the third directional valve (343) is connected to port A5. The oil outlet of the fifth directional valve (345) is connected to port A4.

5. The high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors according to claim 4, characterized in that: The first directional valve (341) is a three-position four-way solenoid directional valve, and the middle position function of the first directional valve (341) is H-shaped.

6. The high-flow hydraulic lifting and hydraulic output composite hydraulic system for tractors according to claim 4, characterized in that: The second reversing valve (342), the third reversing valve (343), the fourth reversing valve (344), and the fifth reversing valve (345) are two-position, two-way, zero-leakage electromagnetic reversing valves.

Images