Tractor hydraulic lifting system capable of achieving automatic limiting and tractor

Abstract

The invention relates to the technical field of tractor hydraulic control, in particular to a tractor hydraulic lifting system capable of achieving automatic limiting and a tractor. An oil inlet of a lifting electromagnetic valve communicates with a port P of a multi-way output valve, and an oil outlet of the lifting electromagnetic valve communicates with an oil inlet of a lifting oil cylinder; an oil outlet of the lifting oil cylinder is communicated with an oil inlet of the descending electromagnetic valve, and an oil outlet of the descending electromagnetic valve is communicated with a port R of the multi-way output valve; an oil inlet of the pressurizing electromagnetic valve is communicated with a port P of the multi-way output valve, an oil outlet of the pressurizing electromagnetic valve is communicated with an oil inlet of the limiting rod oil cylinder, an oil outlet of the limiting rod oil cylinder is communicated with an oil inlet of the floating electromagnetic valve, and an oil outlet of the floating electromagnetic valve is communicated with a port P of the multi-way output valve. The hydraulic limiting three-point suspension system has the beneficial effects that the automation degree of the tractor is greatly improved, the three-point suspension stability of the tractor in the transition process, the turning-around process and the like is greatly improved, and therefore the comfort degree of the whole tractor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tractor hydraulic control, and particularly relates to a tractor hydraulic lifting system with automatic limit and a tractor. Background Art

[0002] With the development of technology, not only the requirements for tractors are getting higher and higher with the diversification of agricultural implements, but also the ergonomic requirements for tractor operations are getting higher and higher. At present, the three-point hitch of tractors at home and abroad is mechanically limited. When hooking up implements, the driver needs to get out of the vehicle to operate. Moreover, the three-point hitch in the current technical state will swing left and right during transfer or turning, which reduces the service life of the three-point hitch and seriously affects the driving experience of the driver. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a tractor hydraulic lifting system with automatic limit and a tractor to solve the deficiencies in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A tractor hydraulic lifting system with automatic limit includes a hydraulic oil tank, a lifting pump assembly, and a multi-way output valve. The inlet of the lifting pump assembly is connected to the hydraulic oil tank through a pipeline, the outlet of the lifting pump assembly is connected to the P port of the multi-way output valve through a pipeline, and the R port of the multi-way output valve is connected to the hydraulic oil tank through a pipeline; A lowering solenoid valve, a pressurizing solenoid valve, a floating solenoid valve, and a lifting solenoid valve are provided in the multi-way output valve. The inlet of the lifting solenoid valve is connected to the P port of the multi-way output valve through a lifting inlet pipeline, the outlet of the lifting solenoid valve is connected to the inlet of the lifting cylinder through a pipeline, the outlet of the lifting cylinder is connected to the inlet of the lowering solenoid valve through a pipeline, and the outlet of the lowering solenoid valve is connected to the R port of the multi-way output valve through a pipeline; The inlet of the pressurizing solenoid valve is connected to the P port of the multi-way output valve through a pipeline, the outlet of the pressurizing solenoid valve is connected to the inlet of the limit rod cylinder through a pipeline, the outlet of the limit rod cylinder is connected to the inlet of the floating solenoid valve through a pipeline, and the outlet of the floating solenoid valve is connected to the P port of the multi-way output valve through a pipeline.

[0005] The beneficial effects of the present invention are: The hydraulic limit three-point hitch system not only greatly increases the automation degree of the tractor, but also greatly increases the stability of the three-point hitch during the transfer, turning, etc. of the tractor, thereby improving the overall comfort of the tractor.

[0006] Based on the above technical solutions, the present invention can also be improved as follows.

[0007] Further, a shuttle valve and a pressure compensation valve are also provided inside the multi-way output valve. The pressure compensation valve is arranged on the lifting inlet oil pipeline. The oil outlet of the lifting solenoid valve is connected to the pressure feedback channel of the multi-way output valve through the shuttle valve. The shuttle valve conveys the selected load pressure to the spring side of the pressure compensation valve.

[0008] The beneficial effect of adopting the above further solution is that by arranging the shuttle valve and the pressure compensation valve, the pressure compensation valve can be set to meet the simultaneous operation of multiple loads, thereby achieving the balance of each load, and making the adaptability, comfort and safety of the tractor and the actuating element higher.

[0009] Further, a safety overflow valve is also provided inside the multi-way output valve. The oil outlet of the lifting solenoid valve is communicated with the oil inlet of the safety overflow valve through a pipeline. The oil outlet of the safety overflow valve is communicated with the R port of the multi-way output valve through a pipeline.

[0010] The beneficial effect of adopting the above further solution is that the setting of the safety overflow valve can perform overflow unloading when the oil pressure at the oil outlet of the lifting solenoid valve is too high, and can also relieve pressure when the suspension collides during the lifting process, avoiding damage to the hanging arm caused by continuous lifting.

[0011] Further, the lifting pump assembly includes a main pump and a booster pump. The hydraulic oil tank is communicated with the input end of the booster pump through a first pipeline. The output end of the booster pump is communicated with the input end of the main pump through a second pipeline.

[0012] The beneficial effect of adopting the above further solution is that by arranging the booster pump, enough hydraulic oil can be provided for the use of multiple actuating elements to meet the pressure requirements of the simultaneous use of multiple actuating elements.

[0013] Further, an initial oil suction filtering mechanism is provided on the first pipeline.

[0014] The beneficial effect of adopting the above further solution is that the setting of the initial oil suction filtering mechanism can initially filter the hydraulic oil to avoid the influence of impurities on the use of each valve.

[0015] Further, an oil suction fine filtering mechanism is provided on the second pipeline.

[0016] The beneficial effect of adopting the above further solution is that the setting of the oil suction fine filtering mechanism can further purify the hydraulic oil and reduce the failure rate during the use of the hydraulic system.

[0017] Further, a safety valve is provided inside the multi-way output valve. The oil inlet of the safety valve is communicated with the P port of the multi-way output valve. The oil outlet of the safety valve is communicated with the R port of the multi-way output valve.

[0018] The beneficial effects of adopting the above further solution are as follows: The setting of the safety valve can provide overload protection for the system. When the load exceeds the system set value, the safety valve opens to unload, ensuring the safe operation of the system.

[0019] Further, a pressure reducing valve is provided inside the multi-way output valve. The oil inlet of the pressure reducing valve is communicated with the P port of the multi-way output valve, and the oil outlet of the pressure reducing valve is communicated with the R port of the multi-way output valve.

[0020] The beneficial effects of adopting the above further solution are as follows: The setting of the pressure reducing valve can achieve the pressure reduction of the system as needed, further ensuring the use safety of the system.

[0021] Further, an LS interface is provided on the multi-way output valve and is communicated with the pressure feedback channel of the multi-way output valve. The LS interface is communicated with the LS control valve of the main pump through a pipeline.

[0022] The beneficial effects of adopting the above further solution are as follows: The setting of the LS interface facilitates the connection between the LS control valve of the main pump and the pressure feedback channel of the multi-way output valve.

[0023] The present invention also provides a tractor to solve the above technical problems, including the above-mentioned automatically limitable tractor hydraulic lifting system.

[0024] The beneficial effects of adopting the above solution are as follows: The hydraulic limit three-point hitch system not only greatly increases the automation degree of the tractor, but also greatly increases the three-point hitch stability of the tractor during processes such as transfer and turning, thereby improving the overall comfort of the tractor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a structural schematic diagram of the present invention;

[0026] Figure 2 is Figure 1 the internal structure schematic diagram of the multi-way output valve in

[0027] In the drawings, the list of components represented by each reference numeral is as follows:

[0028] 1, oil suction primary filter mechanism; 2, booster pump; 3, oil suction fine filter mechanism; 4, main pump; 5, safety valve; 6, lowering solenoid valve; 7, pressurizing solenoid valve; 8, floating solenoid valve; 9, limit rod oil cylinder; 10, lifting oil cylinder; 11, lifting solenoid valve; 12, hydraulic oil tank; 13, multi-way output valve; 14, shuttle valve; 15, pressure compensation valve; 16, safety overflow valve; 17, first pipeline; 18, second pipeline; 19, pressure reducing valve; 20, LS interface; 21, LS control valve; 22, pressure feedback channel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The principles and features of the present invention will be described below in conjunction with the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] Embodiment 1

[0031] As Figure 1 , Figure 2 shown, this embodiment discloses a tractor hydraulic lifting system with automatic limit function, including a hydraulic oil tank 12, a lifting pump assembly and a multi-way output valve 13. The inlet of the lifting pump assembly is connected to the hydraulic oil tank 12 through a pipeline, the outlet of the lifting pump assembly is connected to the P port of the multi-way output valve 13 through a pipeline, and the R port of the multi-way output valve 13 is connected to the hydraulic oil tank 12 through a pipeline.

[0032] In this embodiment, the lifting pump assembly includes a main pump 4 and a booster pump 2. The hydraulic oil tank 12 is connected to the input end of the booster pump 2 through a first pipeline 17, and the output end of the booster pump 2 is connected to the input end of the main pump 4 through a second pipeline 18. By setting the booster pump 2, sufficient hydraulic oil can be provided for the use of multiple actuators to meet the pressure requirements of multiple actuators for simultaneous use. An initial oil suction filtering mechanism 1 is provided on the first pipeline 17, and a fine oil suction filtering mechanism 3 is provided on the second pipeline 18. The setting of the initial oil suction filtering mechanism 1 can preliminarily filter the hydraulic oil to avoid the influence of impurities on the use of each valve, and the setting of the fine oil suction filtering mechanism 3 can further purify the hydraulic oil and reduce the failure rate during the use of the hydraulic system.

[0033] The multi-way output valve 13 is internally provided with a lowering solenoid valve 6, a pressurizing solenoid valve 7, a floating solenoid valve 8 and a lifting solenoid valve 11. The inlet of the lifting solenoid valve 11 is connected to the P port of the multi-way output valve 13 through a lifting inlet pipeline, the outlet of the lifting solenoid valve 11 is connected to the inlet of a lifting cylinder 10 through a pipeline, the outlet of the lifting cylinder 10 is connected to the inlet of the lowering solenoid valve 6 through a pipeline, and the outlet of the lowering solenoid valve 6 is connected to the R port of the multi-way output valve 13 through a pipeline; the inlet of the pressurizing solenoid valve 7 is connected to the P port of the multi-way output valve 13 through a pipeline, the outlet of the pressurizing solenoid valve 7 is connected to the inlet of a limit rod cylinder 9 through a pipeline, the outlet of the limit rod cylinder 9 is connected to the inlet of the floating solenoid valve 8 through a pipeline, and the outlet of the floating solenoid valve 8 is connected to the P port of the multi-way output valve 13 through a pipeline.

[0034] In this embodiment, a shuttle valve 14 and a pressure compensation valve 15 are further provided in the multi-way output valve 13. The pressure compensation valve 15 is arranged on the lifting inlet pipeline. The oil outlet of the lifting solenoid valve 11 is connected to the pressure feedback channel 22 of the multi-way output valve 13 through the shuttle valve 14. The shuttle valve 14 conveys the selected load pressure to the spring side of the pressure compensation valve 15. Through the settings of the shuttle valve 14 and the pressure compensation valve 15, by setting the pressure compensation valve 15, it is possible to meet the simultaneous operation of multiple loads, thereby achieving the balance of each load, and making the adaptability, comfort, and safety of the tractor and the actuating element higher.

[0035] Preferably, a safety overflow valve 16 is further provided in the multi-way output valve 13. The oil outlet of the lifting solenoid valve 11 is communicated with the oil inlet of the safety overflow valve 16 through a pipeline. The oil outlet of the safety overflow valve 16 is communicated with the R port of the multi-way output valve 13 through a pipeline. The setting of the safety overflow valve 16 can perform overflow unloading when the oil pressure at the oil outlet of the lifting solenoid valve 11 is too high, and can also relieve pressure when the suspension collides during the lifting process, avoiding damage to the hanging arm caused by continuous lifting.

[0036] In this embodiment, a safety valve 5 is provided in the multi-way output valve 13. The oil inlet of the safety valve 5 is communicated with the P port of the multi-way output valve 13, and the oil outlet of the safety valve 5 is communicated with the R port of the multi-way output valve 13. The setting of the safety valve 5 can provide overload protection for the system. When the load exceeds the system setting value, the safety valve 5 opens for unloading to ensure the safe operation of the system.

[0037] A pressure reducing valve 19 is provided in the multi-way output valve 13. The oil inlet of the pressure reducing valve 19 is communicated with the P port of the multi-way output valve 13, and the oil outlet of the pressure reducing valve 19 is communicated with the R port of the multi-way output valve 13. The setting of the pressure reducing valve 19 can achieve the pressure reduction of the system as needed, further ensuring the use safety of the system.

[0038] An LS interface 20 communicated with the pressure feedback channel 22 of the multi-way output valve 13 is provided on the multi-way output valve 13. The LS interface 20 is communicated with the LS control valve 21 of the main pump 4 through a pipeline (the setting of the LS control valve 21 on the main pump 4 is prior art in the art, and the specific structure and principle will not be described). The setting of the LS interface 20 facilitates the communication between the LS control valve 21 of the main pump 4 and the pressure feedback channel 22 of the multi-way output valve 13.

[0039] Working principle: The boost pump 2 sucks oil from the hydraulic oil tank 12 through the suction coarse filter and supplies the clean hydraulic oil to the inlet of the main pump 4 (piston pump) through the suction fine filter. The main pump 4 supplies the pressurized oil to the control valve group. The safety valve 5 provides overload protection for the system. When the load exceeds the system set value, the safety valve 5 opens for unloading to ensure the safe operation of the system. The lowering solenoid valve 6, the pressurizing solenoid valve 7, the floating solenoid valve 8, and the lifting solenoid valve 11 are all solenoid valves controlled by the tractor controller. According to the driver's working requirements, the tractor is operated to make the tractor controller control whether the solenoid valve is energized. When the lifting solenoid valve 11 is energized, the pressurized oil of the main pump 4 is supplied to the large chamber of the lifting cylinder 10 through the lifting solenoid valve 11, and the lifting cylinder 10 extends. When the lifting solenoid valve 11 is de-energized, the lifting cylinder 10 stops extending. When the lowering solenoid valve 6 is energized, the oil in the large chamber of the lifting cylinder 10 returns to the hydraulic oil tank 12 through the lowering solenoid valve 6, and the lifting cylinder 10 retracts. When the pressurizing solenoid valve 7 is energized, the pressurized oil of the main pump 4 is supplied to the large chamber of the limit rod cylinder 9 through the pressurizing solenoid valve 7, and the limit rod cylinder 9 extends. When the pressurizing solenoid valve 7 is de-energized, the limit rod cylinder 9 stops extending. When the floating solenoid valve 8 is energized, the large chamber of the limit rod cylinder 9 returns to the hydraulic oil tank 12 through the floating solenoid valve 8, and the limit rod cylinder 9 enters the floating state. The extension and retraction of the lifting cylinder 10 can control the rise and fall of the working device. The extension and floating of the limit rod cylinder 9 can control the span of the limit rod and whether it can swing (automatic attachment of the implement, implement limit).

[0040] This system is combined with an electronic control strategy. To meet the working conditions of all implements, there are two modes, side swing and no side swing, set on the cab control screen. When the tractor is transporting with the implement and the implement is raised to the transport position, to prevent pitching and yaw movements and there should be no lateral clearance. At this time, the pressurizing solenoid valve 7 is energized, and the pressurized oil enters the limit rod cylinder 9, and the limit rod cylinder 9 extends to limit the implement. When the tractor is attaching and working with the implement, the side swing and no side swing modes can be selected according to the attached implement. In the no side swing mode, the floating solenoid valve 8 is energized, and the limit rod cylinder 9 is in the floating state. At this time, the three-point hitch and the mechanical limit three-point hitch work in the same state. When the no side swing mode is selected, the tractor ECU control strategy will automatically control the switching between the side swing and no side swing states of the three-point hitch according to the lifting height of the three-point hitch (the lifting set height calibrated before leaving the factory), which will greatly improve the operation efficiency, driving experience of the tractor and the service life of the three-point hitch. When the tractor is attaching the implement, automatic attachment can be achieved by controlling the limit rod cylinder 9.

[0041] Embodiment 2

[0042] This embodiment discloses a tractor, including the above-mentioned tractor hydraulic lifting system with automatic limiting.

[0043] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "length", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "inner", "outer", "peripheral side", "circumferential direction", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0044] In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0045] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0047] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatically limitable hydraulic lifting system for a tractor, characterized in that, It includes a hydraulic oil tank (12), a lift pump assembly, and a multi-way output valve (13). The inlet of the lift pump assembly is connected to the hydraulic oil tank (12) through a pipeline. The outlet of the lift pump assembly is connected to the P port of the multi-way output valve (13) through a pipeline. The R port of the multi-way output valve (13) is connected to the hydraulic oil tank (12) through a pipeline. A lowering solenoid valve (6), a pressurizing solenoid valve (7), a floating solenoid valve (8), and a lifting solenoid valve (11) are provided inside the multi-way output valve (13). The inlet of the lifting solenoid valve (11) is connected to the P port of the multi-way output valve (13) through a lifting inlet pipeline. The outlet of the lifting solenoid valve (11) is connected to the inlet of a lift cylinder (10) through a pipeline. The outlet of the lift cylinder (10) is connected to the inlet of the lowering solenoid valve (6) through a pipeline. The outlet of the lowering solenoid valve (6) is connected to the R port of the multi-way output valve (13) through a pipeline. The inlet of the pressurizing solenoid valve (7) is connected to the P port of the multi-way output valve (13) through a pipeline. The outlet of the pressurizing solenoid valve (7) is connected to the inlet of a limit rod cylinder (9) through a pipeline. The outlet of the limit rod cylinder (9) is connected to the inlet of the floating solenoid valve (8) through a pipeline. The outlet of the floating solenoid valve (8) is connected to the P port of the multi-way output valve (13) through a pipeline.

2. The automatic limit tractor hydraulic lift system according to claim 1, wherein A shuttle valve (14) and a pressure compensating valve (15) are also provided inside the multi-way output valve (13). The pressure compensating valve (15) is arranged on the lifting inlet pipeline. The outlet of the lifting solenoid valve (11) is connected to the pressure feedback channel (22) of the multi-way output valve (13) through the shuttle valve (14). The shuttle valve (14) conveys the selected load pressure to the spring side of the pressure compensating valve (15).

3. A tractor hydraulic lifting system with automatic limit according to claim 1, characterized in that, A safety relief valve (16) is also provided inside the multi-way output valve (13). The outlet of the lifting solenoid valve (11) is connected to the inlet of the safety relief valve (16) through a pipeline. The outlet of the safety relief valve (16) is connected to the R port of the multi-way output valve (13) through a pipeline.

4. A tractor hydraulic lifting system with automatic limit according to claim 1, characterized in that, The lift pump assembly includes a main pump (4) and a booster pump (2). The hydraulic oil tank (12) is connected to the input end of the booster pump (2) through a first pipeline (17). The output end of the booster pump (2) is connected to the input end of the main pump (4) through a second pipeline (18).

5. The automatic position-limiting tractor hydraulic lifting system according to claim 4, wherein An initial oil suction filtering mechanism (1) is provided on the first pipeline (17).

6. A tractor hydraulic lifting system capable of automatic limiting according to claim 4, characterized in that, A fine oil suction filtering mechanism (3) is provided on the second pipeline (18).

7. A tractor hydraulic lift system capable of automatic limiting according to any one of claims 1 to 6, characterized in that, A safety valve (5) is provided inside the multi-way output valve (13). The inlet of the safety valve (5) is connected to the P port of the multi-way output valve (13). The outlet of the safety valve (5) is connected to the R port of the multi-way output valve (13).

8. A tractor hydraulic lifting system with automatic limit according to any one of claims 1 to 6, characterized in that, A pressure reducing valve (19) is provided inside the multi-way output valve (13). The oil inlet of the pressure reducing valve (19) is communicated with the P port of the multi-way output valve (13), and the oil outlet of the pressure reducing valve (19) is communicated with the R port of the multi-way output valve (13).

9. A tractor hydraulic lift system with automatic limit according to any one of claims 4 to 6, characterized in that, An LS interface (20) communicated with the pressure feedback channel (22) of the multi-way output valve (13) is provided on the multi-way output valve (13), and the LS interface (20) is communicated with the LS control valve (21) of the main pump (4) through a pipeline.

10. A tractor, characterized in that, It includes the automatically position-limiting tractor hydraulic lifting system according to any one of claims 1 to 9.

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