Tractor hydraulic system and tractor

Abstract

The invention belongs to the technical field of operation machinery and provides a tractor hydraulic system and a tractor. The tractor hydraulic system comprises a hydraulic output unit, a lifting mechanism, a steering mechanism and a flow dividing unit, the lifting mechanism comprises a working pump and a lifting unit which are sequentially connected, the steering mechanism comprises a steering pump and a steering execution unit which are sequentially connected, and the flow dividing unit is used for partially dividing hydraulic oil output by the working pump and the steering pump. And the hydraulic pressure is transmitted to the hydraulic input end of the hydraulic output unit. According to the hydraulic system of the tractor, the flow dividing unit is arranged, so that the flow needed when the steering execution unit and the lifting unit work normally can be guaranteed, large-flow output of the hydraulic output unit can be achieved, and therefore the probability that one of an accessory, the steering execution unit and the lifting unit is out of control due to insufficient flow is effectively reduced; the operation stability of the tractor is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of operating machinery, and in particular relates to a tractor hydraulic system and a tractor. Background Art

[0002] With the evolution of the tractor market, in addition to the traditional farming and pulling functions, some tractors also have loading functions. Loading function refers to connecting other functional mechanisms to the hydraulic output mechanism of the tractor to achieve more functions of the tractor, such as installing a bucket on the hydraulic output mechanism of the tractor to achieve the tractor's earth-moving operation.

[0003] When the tractor is loaded with other functional mechanisms, the required flow rate will be much greater than the output flow rate during tillage. If the traditional tractor hydraulic system is used to supply oil to the tractor's steering actuator unit, lifting unit and hydraulic external transmission mechanism respectively, in some scenarios, it may cause uneven oil distribution among the hydraulic external transmission mechanism, steering actuator unit and lifting unit, causing the tractor to lose control. Summary of the invention

[0004] In view of the above-mentioned defects or shortcomings, the present invention provides a tractor hydraulic system and a tractor, aiming to solve the technical problem that the hydraulic output mechanism of the existing tractor may have uneven oil distribution in certain scenarios.

[0005] To achieve the above-mentioned purpose, the present invention provides a tractor hydraulic system, comprising a hydraulic output unit, a lifting mechanism, a steering mechanism and a diverter unit, the lifting mechanism comprising a working pump and a lifting unit connected in sequence, the steering mechanism comprising a steering pump and a steering execution unit connected in sequence, the diverter unit being used to divert part of the hydraulic oil output by the working pump and the steering pump, and output it to the hydraulic input end of the hydraulic output unit, wherein, when the lifting unit is working, the flow input to the hydraulic input end is equal to the total flow output by the working pump and the steering pump minus the flow of the working pump and the steering pump respectively diverted to the lifting unit and the steering execution unit through the diverter unit, and when the lifting unit is not working, the flow input to the hydraulic input end is equal to the total flow output by the working pump and the steering pump minus the flow of the steering pump diverted to the steering execution unit through the diverter unit.

[0006] In an embodiment of the present invention, the diverter unit includes a first diverter valve, which is provided with a first input port, a first diverter outlet and a second diverter outlet. The first input port is hydraulically connected to the pump outlet of the working pump, and the first diverter outlet and the second diverter outlet are hydraulically connected to the lifting unit and the hydraulic input end respectively.

[0007] In an embodiment of the present invention, the lifting unit includes a lifting cylinder and a lifting reversing valve. One side of the lifting reversing valve is connected to the first diversion outlet and the system oil return circuit, and the other side is connected to the lifting cylinder and the hydraulic input end. The lifting reversing valve is provided with a cylinder shut-off valve position and a cylinder working valve position. The cylinder working valve position is used to control the hydraulic oil of the first diversion outlet to flow to the lifting cylinder, and to control the cut-off between the lifting reversing valve and the hydraulic input end. The cylinder shut-off valve position is used to control the hydraulic oil of the first diversion outlet to flow to the hydraulic input end, and to control the cut-off between the lifting cylinder and the lifting reversing valve.

[0008] In an embodiment of the present invention, the lifting reversing valve is also provided with a cylinder floating valve position, which is used to control the connection between the rod chamber working oil circuit and the rodless chamber working oil circuit of the lifting cylinder, and to control the hydraulic oil of the first diversion outlet to flow to the hydraulic input end.

[0009] In an embodiment of the present invention, the cylinder working valve position includes a lifting control valve position and a lowering control valve position. The lifting control valve position is configured such that the first diversion outlet is connected to the rod chamber working oil circuit of the lifting cylinder, and the system return oil circuit is connected to the rodless chamber working oil circuit of the lifting cylinder. The lowering control valve position is configured such that the first diversion outlet is connected to the rodless chamber working oil circuit of the lifting cylinder, and the system return oil circuit is connected to the rod chamber working oil circuit of the lifting cylinder.

[0010] In an embodiment of the present invention, the diverter unit includes a second diverter valve, which is provided with a second input port, a third diverter outlet and a fourth diverter outlet. The second input port is hydraulically connected to the pump outlet of the steering pump, and the third diverter outlet and the fourth diverter outlet are hydraulically connected to the steering execution unit and the hydraulic input end respectively.

[0011] In an embodiment of the present invention, the steering execution unit includes a steering cylinder and a steering controller. The steering controller is connected between the third branch outlet and the steering cylinder and is used to control the oil inlet and outlet directions of the steering cylinder.

[0012] In an embodiment of the present invention, the hydraulic output unit includes a plurality of groups of output reversing valves arranged in parallel, and the plurality of groups of output reversing valves are configured to return oil in a neutral position.

[0013] In an embodiment of the present invention, the working pump and the steering pump are double pumps.

[0014] To achieve the above object, the present invention further provides a tractor, wherein the tractor comprises the tractor hydraulic system described above.

[0015] Through the above technical solution, the tractor hydraulic system provided by the embodiment of the present invention has the following beneficial effects:

[0016] When the hydraulic output unit outputs flow and the lifting unit is not working, the working pump and the steering pump jointly supply oil to the hydraulic output unit through the diverter unit to achieve a larger flow output of the hydraulic output unit. When the hydraulic output unit outputs flow and the lifting unit is working, the diverter unit will divert the flow output of the working pump, so that part of it is supplied to the lifting unit, and the excess part is supplied to the hydraulic output unit. Through the auxiliary oil supply of the steering pump, the hydraulic output unit and the lifting unit can be ensured to work normally, and the flow required by the hydraulic output unit and the lifting unit is prevented from exceeding the output flow of the working pump, resulting in the tractor losing control. The diversion of the steering pump by the diverter unit can ensure that the required flow of the steering execution unit is sufficient when it needs to work, and avoid the hydraulic output unit working to affect the normal steering function of the tractor. In summary, the tractor hydraulic system in the present invention is provided with a diverter unit to divert the working pump and the steering pump, which can not only ensure the flow required when the steering execution unit and the lifting unit work normally, but also achieve the normal flow output of the hydraulic output unit, thereby effectively reducing the probability of the tractor losing control due to uneven flow distribution of the hydraulic output unit, the steering execution unit, and the lifting unit, and increasing the stability of the tractor operation.

[0017] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide an understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 is a connection principle diagram of a tractor hydraulic system according to an embodiment of the present invention;

[0020] Figure 2 is a structural principle diagram of a lifting reversing valve according to an embodiment of the present invention;

[0021] Figure 3 is a diagram showing the flow of hydraulic oil to the hydraulic output unit of the tractor hydraulic system when the lifting mechanism is not working according to an embodiment of the present invention;

[0022] Figure 4 It is a flow chart of hydraulic oil flowing to the hydraulic output unit when the lifting mechanism of the tractor hydraulic system in an embodiment of the present invention is working.

[0023] Description of Reference Numerals

[0024] 1. Hydraulic output unit; 11. Output reversing valve union; 12. Hydraulic input end; 21. Working pump; 22. Lifting unit; 221. Lifting reversing valve; P. Oil inlet interface; T. Oil return interface; A1. Rodless chamber connecting oil port; A2. Rod chamber connecting oil port; A3. Converging connecting oil port; 222. Lifting cylinder; 31. Steering pump; 32. Steering execution unit; 321. Steering cylinder; 322. Steering controller; 4. Diverter unit; 41. First diverter valve; a. First input port; b. First diverter outlet; c. Second diverter outlet; 42. Second diverter valve; d. Second input port; e. Third diverter outlet; f. Fourth diverter outlet. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0026] The tractor hydraulic system and the tractor according to the present invention will be described below with reference to the accompanying drawings.

[0027] A tractor generally includes a frame assembly for traveling and an attachment suspension mechanism arranged at the rear of the frame assembly. The attachment suspension mechanism is used to tow various attachments to realize different modes of operation of the tractor. The tractor generally also includes a lifting mechanism, which is used to drive the towed attachments to rise and fall. For example, if the attachment is an agricultural implement, after the agricultural implement is installed on the attachment suspension mechanism, the agricultural implement can be towed by the tractor to realize the farming operation of the tractor, and the agricultural implement can be lifted from the soil or inserted into the soil through the lifting mechanism.

[0028] Some tractor hydraulic systems are in dual-pump working mode. The lifting mechanism, as a part of the tractor hydraulic system, is powered by the working pump 21 in the tractor hydraulic system. At the same time, when the frame assembly is turning, the steering pump 31 in the tractor hydraulic system is also required to provide driving force for the steering execution unit 32.

[0029] In order to enrich the application scenarios, some tractor hydraulic systems are also equipped with a hydraulic output unit 1. When a hydraulically driven attachment (such as a hydraulically driven branch pruners, buckets, etc.) is installed on the attachment suspension mechanism, the attachment is connected to the hydraulic output unit 1, so that the pressure oil in the tractor hydraulic system can be used to provide power for the attachment.

[0030] However, if the hydraulic output unit 1 is directly connected to the working pump 21 or the steering pump 31, the flow output of the hydraulic output unit 1 will have a great impact on the input flow of the steering actuator unit 32 or the lifting unit 22. For example, when the hydraulic output unit 1 is outputting a large flow, if the tractor is performing a steering operation or a lifting operation at the same time, the hydraulic output unit 1, the steering actuator unit 32, and the lifting unit 22 may be unevenly distributed with oil, and one of them may be insufficiently supplied with oil or supplied with oil too quickly, causing the tractor to lose control.

[0031] For this reason, the present invention designs a tractor hydraulic system, such as Figure 1 As shown, the tractor hydraulic system includes a hydraulic output unit 1 , a lifting mechanism, a steering mechanism and a diverter unit 4 .

[0032] The hydraulic output unit 1 is provided with an external interface for connecting with an external attachment.

[0033] The lifting mechanism includes a working pump 21 and a lifting unit 22 which are connected in sequence.

[0034] The steering mechanism comprises a steering pump 31 and a steering actuator unit 32 which are connected in sequence. The steering actuator unit 32 is used to provide steering assistance when the frame assembly is turned.

[0035] The flow splitter unit 4 is used to split part of the hydraulic oil outputted by the working pump 21 and the steering pump 31 and output the hydraulic oil to the hydraulic input end 12 of the hydraulic output unit 1 .

[0036] Among them, when the lifting unit 22 is working, the flow input into the hydraulic input terminal 12 is equal to the total flow output by the working pump 21 and the steering pump 31 minus the flow of the working pump 21 and the steering pump 31 respectively diverted to the lifting unit 22 and the steering execution unit 32 through the diversion unit 4; when the lifting unit 22 is not working, the flow input into the hydraulic input terminal 12 is equal to the total flow output by the working pump 21 and the steering pump 31 minus the flow of the steering pump 31 diverted to the steering execution unit 32 through the diversion unit 4.

[0037] When the hydraulic output unit 1 outputs flow and the lifting unit 22 is not working, the working pump 21 and the steering pump 31 jointly supply oil to the hydraulic output unit 1 through the diverter unit 4. At this time, the flow input to the hydraulic input end 12 is equal to the total flow output by the working pump 21 and the steering pump 31 minus the flow diverted by the steering pump 31 to the steering execution unit 32 through the diverter unit 4. Through the auxiliary oil supply of the steering pump 31 and the full oil supply of the working pump 21, a larger flow output of the hydraulic output unit 1 is achieved. When the hydraulic output unit 1 outputs flow and the lifting unit 22 is working, the diverter unit 4 will divert the output flow of the working pump 21, so that part of it is supplied to the lifting unit 22, and the remaining part is supplied to the hydraulic output unit 1. At this time, the flow input to the hydraulic input end 12 is equal to the total flow output by the working pump 21 and the steering pump 31 minus the flow of the working pump 21 and the steering pump 31 respectively diverted to the lifting unit 22 and the steering execution unit 32 through the diverter unit 4. Through the auxiliary oil supply of the steering pump 31, the normal operation of the hydraulic output unit 1 and the lifting unit 22 can be ensured, and the required flow of the hydraulic output unit 1 and the lifting unit 22 can be avoided to exceed the output flow of the working pump 21, resulting in the tractor losing control. The diversion of the steering pump 31 by the diverter unit 4 can ensure that the steering execution unit 32 has sufficient flow when it needs to work, so as to avoid the operation of the hydraulic output unit 1 affecting the normal steering function of the tractor. In summary, the tractor hydraulic system in the present invention diverts the working pump 21 and the steering pump 31 by setting the diversion unit 4, which can not only ensure the flow required for the normal operation of the steering execution unit 32 and the lifting unit 22, but also realize the normal flow output of the hydraulic output unit 1, thereby effectively reducing the probability of the tractor losing control due to uneven flow distribution of the hydraulic output unit 1, the steering execution unit 32, and the lifting unit 22, and increasing the stability of the tractor operation.

[0038] like Figure 1 , Figure 3 and Figure 4As shown, in the embodiment of the present invention, the flow diverter unit 4 includes a first flow diverter valve 41, and the first flow diverter valve 41 is provided with a first input port a, a first flow diverter outlet b and a second flow diverter outlet c. The first input port a is hydraulically connected to the pump outlet of the working pump 21, and the first flow diverter outlet b and the second flow diverter outlet c are hydraulically connected to the lifting unit 22 and the hydraulic input end 12, respectively. The first flow diverter valve 41 is a single-way stable flow diverter valve, and a throttling channel is provided between the first flow diverter outlet b and the first input port a. When the hydraulic oil output by the working pump 21 flows to the first input port a, a part of it will flow to the first flow diverter outlet b through the throttling channel, and a part of it will flow to the hydraulic output unit 1 from the second flow diverter outlet c. Affected by the load change of the hydraulic output unit 1, the speed of the tractor power element (such as the engine) will change, and the working pump takes power from the tractor power element. Taking an oil-driven tractor as an example, when the oil-driven tractor works under different working conditions, the engine speed is different, resulting in different output flow rates of the working pump 21 and the steering pump 31. By setting the throttling channel, it can be ensured that the flow rate from the first input port a to the first diversion outlet b is maintained in a certain stable value range. The flow rate in this range can ensure the normal operation of the lifting mechanism and ensure that the flow rate of the first diversion outlet b is not affected by the change in engine speed.

[0039] like Figure 1 , Figure 3 and Figure 4 As shown, in an embodiment of the present invention, the lifting unit 22 includes a lifting cylinder 222 and a lifting reversing valve 221. One side of the lifting reversing valve 221 is connected to the first diversion outlet b and the system oil return circuit, and the other side is connected to the lifting cylinder 222 and the hydraulic input end 12. The lifting reversing valve 221 is provided with a cylinder shut-off valve position and a cylinder working valve position. The cylinder working valve position is used to control the hydraulic oil of the first diversion outlet b to flow to the lifting cylinder 222, and to control the cut-off between the lifting reversing valve 221 and the hydraulic input end 12. The cylinder shut-off valve position is used to control the hydraulic oil of the first diversion outlet b to flow to the hydraulic input end 12, and to control the cut-off between the lifting cylinder 222 and the lifting reversing valve 221.

[0040] Specifically, Figure 2 and Figure 3As shown, the first reversing valve is provided with an inlet side and an outlet side, the inlet side is provided with an oil inlet interface P and an oil return interface T, the outlet side is provided with a rodless chamber connecting oil port A1, a rod chamber connecting oil port A2 and a confluence connecting oil port A3, the oil inlet interface P and the oil return interface T are respectively connected to the first diversion outlet b and the system return oil pipeline, the rodless chamber connecting oil port A1 and the rod chamber connecting oil port A2 are respectively connected to the rodless chamber and the rod chamber pipeline of the lifting cylinder 222, and the confluence connecting oil port A3 pipeline is connected to the hydraulic input end 12 of the hydraulic output unit 1. When the lifting reversing valve 221 is in the cylinder working valve position, one of the oil inlet interface P and the oil return interface T is connected to the rod chamber connecting oil port A2, and the remaining one is connected to the rodless chamber connecting oil port A1, and the confluence connecting oil port A3 is cut off, at this time, the hydraulic oil of the first diversion outlet b flows to the lifting cylinder 222 to drive the lifting cylinder 222 to work. When the lifting reversing valve 221 is in the oil cylinder cut-off valve position, the rodless chamber connecting oil port A1 and the rod chamber connecting oil port A2 are cut off, and the oil inlet interface P is connected to the confluence connecting oil port A3, and the hydraulic oil of the first branch outlet b flows to the hydraulic input end 12 of the hydraulic output unit 1. That is, when the lifting mechanism in the tractor hydraulic system is not working, by connecting the confluence connecting oil port A3 to the hydraulic input end 12, the working pump 21 can fully supply oil to the hydraulic output unit 1.

[0041] like Figure 4 As shown, in an embodiment of the present invention, the cylinder working valve position includes a lifting control valve position for controlling the extension of the lifting cylinder 222 and a lowering control valve position for controlling the retraction of the lifting cylinder 222. The lifting control valve position is configured so that the first diverting outlet b is connected to the rod chamber working oil circuit of the lifting cylinder 222, and the system return oil circuit is connected to the rodless chamber working oil circuit of the lifting cylinder 222, that is, the oil inlet interface P is connected to the rod chamber connecting oil port A2, and the oil return interface T is connected to the rodless chamber connecting oil port A1. The lowering control valve position is configured so that the first diverting outlet b is connected to the rodless chamber working oil circuit of the lifting cylinder 222, and the system return oil circuit is connected to the rod chamber connecting oil port A2 of the lifting cylinder 222. That is, the oil inlet interface P is connected to the rodless chamber connecting oil port A1, and the oil return interface T is connected to the rod chamber connecting oil port A2.

[0042] like Figure 1 and Figure 2As shown, in some usage scenarios, the lifting cylinder 222 needs to have a floating function, so in the embodiment of the present invention, the lifting reversing valve 221 is also provided with a cylinder floating valve position, which is used to control the connection between the rod chamber working oil circuit and the rodless chamber working oil circuit of the lifting cylinder 222, and control the hydraulic oil of the first diversion outlet b to flow to the hydraulic input end 12. That is, when the lifting reversing valve 221 is in the cylinder floating valve position, the rod chamber connecting oil port A2 is connected with the rodless chamber connecting oil port A1, the oil inlet interface P is connected with the confluence connecting oil port A3, and the working pump 21 supplies oil to the hydraulic output unit 1 through the first diversion outlet b, the confluence connecting oil port A3, and the second diversion outlet c.

[0043] like Figure 1 As shown, in an embodiment of the present invention, the diverter unit 4 includes a second diverter valve 42, the second diverter valve 42 is provided with a second input port d, a third diverter outlet e and a fourth diverter outlet f, the second input port d is hydraulically connected to the pump outlet of the steering pump 31, the third diverter outlet e and the fourth diverter outlet f are hydraulically connected to the steering actuator unit and the hydraulic input end 12, respectively. The second diverter valve 42 is also a single-way stable diverter valve, and a throttling channel is also provided between the third diverter outlet e and the second input port d. When the hydraulic oil output by the steering pump 31 flows to the second input port d, a part of it will flow to the third diverter outlet e through the throttling channel, and a part of it will flow to the hydraulic output unit 1 from the fourth diverter outlet f. By setting the throttling channel, it can be ensured that the flow rate from the second input port d to the third diverter outlet e is maintained within a numerical range that ensures normal steering of the steering mechanism. In other words, affected by the load change of the hydraulic output unit 1 or the change of the tractor working condition, the speed of the tractor power element (such as the engine) will change, and the steering pump takes power from the tractor power element. Therefore, the throttling channel is provided to ensure that the flow rate of the third diverter outlet e is not affected by the change of the speed of the tractor power element, thereby avoiding the situation where the load change of the hydraulic output unit 1 causes the driving speed of the steering execution unit 32 to fluctuate.

[0044] In an embodiment of the present invention, the steering execution unit includes a steering cylinder 321 and a steering controller 322. The steering controller 322 is connected between the third branch outlet e and the steering cylinder 321 and is used to control the oil inlet and outlet directions of the steering cylinder 321. The steering controller 322 is connected to the steering wheel in a transmission manner, and is used to control the oil inlet and return directions of the steering cylinder 321 according to the rotation direction of the square plate.

[0045] like Figure 1As shown, it should be particularly emphasized that when the steering controller 322 is in the state of cutting off the steering cylinder 321, the hydraulic oil of the third branch outlet e will continue to enter the steering controller 322 and then return. The purpose of this setting is to ensure that the oil pressure and flow between the steering controller 322 and the third branch outlet e remain stable, and to prevent the load change of the hydraulic output unit 1 from affecting the steering of the steering execution unit.

[0046] like Figure 1 As shown, in the embodiment of the present invention, the hydraulic output unit 1 includes a plurality of groups of output reversing valves 11 arranged in parallel, each of which is provided with an external interface, and a plurality of groups of output reversing valves 11 are configured as mid-position oil return. That is, the output reversing valves 11 are provided with a mid-position oil return channel, and when all the output reversing valves 11 are in the mid-position, the mid-position oil return channel is connected, and the hydraulic oil input from the hydraulic input end 12 will flow back to the oil tank through the mid-position oil return channel, and when a certain output reversing valve 11 is in the reversing valve position, the mid-position oil return channel is cut off, and the hydraulic oil will enter the output reversing valve 11 in the reversing valve position to drive the corresponding mechanism to act.

[0047] like Figure 1 As shown, in the embodiment of the present invention, the working pump 21 and the steering pump 31 are double pumps. When the tractor is an oil-driven tractor, the working pump 21 and the steering pump 31 are both powered by the tractor's engine, and when the tractor is an electric-driven tractor, the working pump 21 and the steering pump 31 are both powered by the motor.

[0048] The beneficial effects of the present invention are described below in conjunction with the specific working process of the tractor hydraulic system.

[0049] like Figure 3 As shown, when the hydraulic output unit 1 supplies oil to the external attachment through the external interface and the lifting mechanism is not working, the lifting reversing valve 221 is in the cylinder stop valve position. At this time, the hydraulic oil output by the working pump 21 is fully supplied to the hydraulic output unit 1 through the first diversion outlet b and the second diversion outlet c. At the same time, the steering pump 31 outputs a part of the hydraulic oil through the third diversion outlet e for oil return, and the excess part flows to the hydraulic output unit 1 through the fourth diversion outlet f. The total flow rate input to the hydraulic output unit 1 is equal to the total output flow rate of the two pumps minus the diversion flow rate of the third diversion outlet e. Through the auxiliary oil supply of the steering pump 31, a large flow output of the hydraulic output unit 1 can be achieved.

[0050] like Figure 4As shown, when the hydraulic output unit 1 supplies oil to the external attachment through the external interface and the lifting mechanism is working, the hydraulic oil output by the working pump 21 flows to the lifting cylinder 222 and the hydraulic output unit 1 through the first diversion outlet b and the second diversion outlet c respectively, and at the same time, the steering pump 31 outputs a part of the hydraulic oil through the third diversion outlet e for oil return, and the excess part flows to the hydraulic output unit 1 through the fourth diversion outlet f. At this time, the flow rate input by the hydraulic input end 12 is equal to the total flow rate output by the working pump 21 and the steering pump 31 minus the diversion flow rate of the first diversion outlet b and the third diversion outlet e. Through the auxiliary oil supply of the steering pump 31, the flow rate input to the hydraulic output unit 1 can be ensured to be sufficient, so as to avoid the working pump 21 supplying oil to the lifting mechanism and the hydraulic output unit 1 at the same time, and the insufficient oil supply may cause one of them to lose control.

[0051] Affected by changes in working conditions, when the speed of the engine power output mechanism (such as the engine, motor) changes, due to the existence of the throttling channel, the flow of the working pump 21 and the steering pump 31 flowing to the lifting unit 22 and the steering execution unit 32 respectively through the diversion unit is almost constant, thereby ensuring the stability of the tractor's steering function and suspension lifting function.

[0052] To achieve the above object, the present invention further provides a tractor, wherein the tractor comprises the tractor hydraulic system described above. Since the tractor adopts all the technical solutions of the above embodiments, it at least has the beneficial effects brought by the above embodiments, which will not be repeated here.

[0053] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0056] Although the embodiments of the present invention have been described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A tractor hydraulic system, characterized in that: The tractor hydraulic system comprises: Hydraulic output unit (1); A lifting mechanism, comprising a working pump (21) and a lifting unit (22) connected in sequence; A steering mechanism, comprising a steering pump (31) and a steering execution unit (32) connected in sequence; A flow splitting unit (4) for splitting a portion of the hydraulic oil output by the working pump (21) and the steering pump (31) and outputting the hydraulic oil to a hydraulic input end (12) of the hydraulic output unit (1); Wherein, when the lifting unit (22) is working, the flow rate input to the hydraulic input end (12) is equal to the total flow rate output by the working pump (21) and the steering pump (31) minus the flow rates diverted by the working pump (21) and the steering pump (31) to the lifting unit (22) and the steering execution unit (32) respectively through the diversion unit (4); when the lifting unit (22) is not working, the flow rate input to the hydraulic input end (12) is equal to the total flow rate output by the working pump (21) and the steering pump (31) minus the flow rate diverted by the steering pump (31) to the steering execution unit (32) through the diversion unit (4).

2. The tractor hydraulic system according to claim 1, characterized in that: The diverter unit (4) comprises a first diverter valve (41), the first diverter valve (41) being provided with a first input port (a), a first diverter outlet (b) and a second diverter outlet (c), the first input port (a) being hydraulically connected to the pump outlet of the working pump (21), the first diverter outlet (b) and the second diverter outlet (c) being hydraulically connected to the lifting unit (22) and the hydraulic input end (12) respectively, and a throttling channel being provided between the first input port (a) and the first diverter outlet (b).

3. The tractor hydraulic system according to claim 2, characterized in that: The lifting unit (22) comprises a lifting cylinder (222) and a lifting reversing valve (221); one side of the lifting reversing valve (221) is connected to the first diverting outlet (b) and the system oil return line, and the other side is connected to the lifting cylinder (222) and the hydraulic input end (12); the lifting reversing valve (221) is provided with a cylinder stop valve position and a cylinder working valve position; the cylinder working valve position is used to control the hydraulic oil of the first diverting outlet (b) to flow to the lifting cylinder (222) and to control the stop between the lifting reversing valve (221) and the hydraulic input end (12); the cylinder stop valve position is used to control the hydraulic oil of the first diverting outlet (b) to flow to the hydraulic input end (12) and to control the stop between the lifting cylinder (222) and the lifting reversing valve (221).

4. The tractor hydraulic system according to claim 3, characterized in that: The lifting reversing valve (221) is also provided with a cylinder floating valve position, and the cylinder floating valve position is used to control the connection between the rod chamber working oil circuit and the rodless chamber working oil circuit of the lifting cylinder (222), and to control the hydraulic oil of the first branch outlet (b) to flow to the hydraulic input end (12).

5. The tractor hydraulic system according to claim 3, characterized in that: The cylinder working valve position includes a lifting control valve position and a lowering control valve position, the lifting control valve position is configured so that the first diversion outlet (b) is connected to the rod chamber working oil circuit of the lifting cylinder (222), the system return oil circuit is connected to the rodless chamber working oil circuit of the lifting cylinder (222), and the lowering control valve position is configured so that the first diversion outlet (b) is connected to the rodless chamber working oil circuit of the lifting cylinder (222), and the system return oil circuit is connected to the rod chamber working oil circuit of the lifting cylinder (222).

6. The tractor hydraulic system according to any one of claims 1 to 5, characterized in that: The diverter unit (4) comprises a second diverter valve (42), the second diverter valve (42) being provided with a second input port (d), a third diverter outlet (e) and a fourth diverter outlet (f), the second input port (d) being hydraulically connected to a pump outlet of the steering pump (31), the third diverter outlet (e) and the fourth diverter outlet (f) being hydraulically connected to the steering actuator unit and the hydraulic input end (12) respectively, and a throttling channel being provided between the second input port (d) and the third diverter outlet (e).

7. The tractor hydraulic system according to claim 6, characterized in that: The steering execution unit comprises a steering cylinder (321) and a steering controller (322); the steering controller (322) is connected between the third branch outlet (e) and the steering cylinder (321) and is used to control the oil inlet and outlet directions of the steering cylinder (321).

8. The tractor hydraulic system according to any one of claims 1 to 5, characterized in that: The hydraulic output unit (1) comprises a plurality of groups of output reversing valves (11) arranged in parallel, and the plurality of groups of output reversing valves (11) are configured to return oil in a neutral position.

9. The tractor hydraulic system according to any one of claims 1 to 5, characterized in that: The working pump (21) and the steering pump (31) are double pumps.

10. A tractor, characterized in that: Comprising a tractor hydraulic system according to any one of claims 1 to 9.

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