Tractor suspension bridge control hydraulic system and tractor

Abstract

The invention relates to a tractor suspension bridge control hydraulic system and a tractor, and the tractor suspension bridge control hydraulic system comprises an oil tank, a gear pump, a suspension bridge control valve, a suspension bridge left side oil cylinder and a suspension bridge right side oil cylinder, an oil outlet of the suspension bridge control valve is communicated with the suspension bridge left side oil cylinder and the suspension bridge right side oil cylinder at the same time, and an oil inlet of the prefill valve set is communicated with an oil outlet of the gear pump. The prefill valve group can be switched to be communicated with the oil inlet of the suspension bridge control valve or communicated with the oil inlet of the tractor rear output multi-way valve and the oil inlet of the lifting valve, and the oil inlet of the tractor rear output multi-way valve and the oil inlet of the lifting valve are communicated with the oil tank. By the adoption of the technical scheme, the technical problem that a gear pump of an existing suspension bridge control hydraulic system works in a high-pressure state all the time, and normal operation of the hydraulic system is affected can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of tractors, and particularly to a hydraulic control system for a tractor suspension bridge and a tractor. Background Art

[0002] Modern agricultural production is an important part of tractor mechanization, which puts forward higher requirements for the reliability, comfort, and adaptability of working conditions of tractors. The front axle hydraulic shock absorption system of a tractor has a good shock absorption system, can adapt to different working conditions, and has good stability.

[0003] In the prior art, such as Figure 9 , the hydraulic control system for a tractor suspension bridge mainly includes an oil tank 1, an oil suction filter 2, a gear pump 3, and a suspension bridge control valve 6. The oil outlet of the suspension bridge control valve 6 is simultaneously connected to the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9 through pipelines respectively. And a left accumulator 7 is connected to the pipeline where the suspension bridge control valve 6 is connected to the left suspension bridge cylinder 8, and a right accumulator 10 is connected to the pipeline where the suspension bridge control valve 6 is connected to the right suspension bridge cylinder 9.

[0004] The above-mentioned existing hydraulic control system for a tractor suspension bridge pumps oil through a gear pump and outputs it to the left and right suspension bridge cylinders through the suspension bridge control valve to achieve control. However, in the actual use process, due to the variety of working conditions, the gear pump will always work under high pressure, and the hydraulic system will heat up and even exceed the temperature requirement for the use of the oil product, affecting the normal operation of the hydraulic system. In this regard, if the suspension bridge control valve is frequently replaced or the pump is increased, it is not conducive to the unification of components and will also lead to an increase in cost. Summary of the Invention

[0005] The present invention provides a hydraulic control system for a tractor suspension bridge and a tractor, which can improve the technical problem that the gear pump of the existing hydraulic control system for a suspension bridge always works under high pressure, resulting in the hydraulic system heating up and even exceeding the temperature requirement for the use of the oil product, affecting the normal operation of the hydraulic system.

[0006] The technical solution for the present invention to solve the above technical problems is as follows: A hydraulic control system for a tractor's suspension bridge, comprising an oil tank, a gear pump, a suspension bridge control valve, a left suspension bridge cylinder and a right suspension bridge cylinder. The inlet of the gear pump is connected to the oil tank, and the outlet of the suspension bridge control valve is simultaneously connected to the left suspension bridge cylinder and the right suspension bridge cylinder. It further includes a charge valve group, a rear output multi-way valve of the tractor and a lift valve. The inlet of the charge valve group is connected to the outlet of the gear pump, and the charge valve group can be switched to connect its outlet to the inlet of the suspension bridge control valve or to the inlet of the rear output multi-way valve and the lift valve of the tractor. The inlet of the rear output multi-way valve and the lift valve of the tractor is connected to the oil tank.

[0007] The beneficial effects of the present invention are as follows: During the working state, the gear pump pumps the oil from the oil tank, and the oil is input into the suspension bridge control valve through the charge valve group, and then output to the left suspension bridge cylinder and the right suspension bridge cylinder, realizing the operation of the left suspension bridge cylinder and the right suspension bridge cylinder. During this oil supply process, when it is not necessary to continuously supply high-pressure oil to the left suspension bridge cylinder and the right suspension bridge cylinder, the oil pressure can be reduced, so that the charge valve group switches the oil port and supplies oil to the rear output multi-way valve and the lift valve of the tractor, and the oil is transported to the oil tank through the rear output multi-way valve and the lift valve of the tractor, realizing high-low pressure switching oil supply, and improving the technical problem that the gear pump of the existing suspension bridge control hydraulic system has been working under high pressure, resulting in the hydraulic system heating up and even exceeding the operating temperature requirements of the oil product, affecting the normal operation of the hydraulic system.

[0008] On the basis of the above technical solution, the present invention can be further improved as follows.

[0009] Further, the charge valve group includes a first priority valve group. The first priority valve group includes a first priority valve. The first priority valve has an inlet port a, a left outlet port b and a right outlet port c. The first priority valve can be switched to connect the inlet port a and the left outlet port b, or the inlet port a and the right outlet port c. The inlet port a is connected to the outlet of the gear pump, and the left outlet port b and the right outlet port c are respectively connected to the inlet of the suspension bridge control valve and the inlet of the rear output multi-way valve and the lift valve of the tractor.

[0010] The beneficial effect of adopting the above further solution is as follows: During the working state, the gear pump pumps the oil from the oil tank, and the first priority valve is switched to connect the inlet port a and the left outlet port b. The oil is input into the suspension bridge control valve through the first priority valve group, and then output to the left suspension bridge cylinder and the right suspension bridge cylinder, realizing the operation of the left suspension bridge cylinder and the right suspension bridge cylinder.

[0011] Further, the charging valve group includes a charging valve provided with an oil inlet P and an oil outlet F1, the oil inlet P is connected to the oil outlet of the gear pump, the oil outlet F1 is connected to the oil inlet of the suspended bridge control valve, and the oil inlet P and the oil outlet F1 are connected through an internal pipe M, the charging valve includes a second priority valve, a charging pressure control valve and a no-load starting valve, the second priority valve is provided with an upper oil inlet a and an upper oil outlet b that are connected, a lower oil inlet c and a lower oil outlet d that are disconnected, and a bottom oil inlet e, and can be switched to the upper oil inlet a and the internal pipe M to be connected, the upper oil outlet b and the oil inlet of the tractor rear output multi-way valve and the lifting valve to be connected, or switched to the lower oil inlet c and the internal pipe M to be connected, and the lower oil outlet d and the oil inlet of the tractor rear output multi-way valve and the lifting valve to be connected; the charging pressure control valve is provided with a first left oil outlet a and a second left oil outlet b that are connected The left oil outlet b, and the disconnected lower right oil outlet c and the right oil inlet d, can be switched to the first left oil outlet a to be connected to the internal pipeline M, and the second left oil outlet b to be connected to the pilot oil port of the charging pressure control valve, or switched to the lower right oil outlet c to be connected to the internal pipeline M, and the right oil inlet d to be connected to the no-load starting valve; the no-load starting valve is provided with a connected upper right oil outlet a and a first upper left oil outlet b, a disconnected lower closed oil port c and a first lower oil outlet d, and can be switched to the upper right oil outlet a to be connected to the pilot oil port of the charging pressure control valve, or to be connected to the pilot oil port of the charging pressure control valve and the right oil inlet d at the same time, and the first upper left oil outlet b to be connected to the bottom oil inlet e of the second priority valve, or switched to the lower closed oil port c to be connected to the pilot oil port of the charging pressure control valve, and the lower oil outlet d to be connected to the bottom oil inlet e of the second priority valve.

[0012] The beneficial effect of adopting the above further scheme is that when working, the gear pump inputs oil into the suspension bridge control valve through the internal pipe M to realize oil supply, and utilizes the second priority valve, the filling pressure control valve and the no-load starting valve to make the gear pump stand by at low pressure after oil supply, or output to the multi-way valve and the lifting valve behind the tractor, so as to avoid the gear pump from frequently switching between high pressure and low pressure, thereby extending the service life of the gear pump.

[0013] Furthermore, the charging valve group further includes an accumulator, and the accumulator is connected to a pipeline between the oil outlet F1 of the charging valve and the oil inlet of the suspension bridge control valve.

[0014] The beneficial effect of adopting the above further scheme is that when the engine is started and the no-load starting valve is powered off, the connected pipeline causes the second priority valve to move in the closing direction. At this time, the oil in the gear pump will give priority to filling the accumulator until the maximum set pressure value is reached.

[0015] Further, the fluid filling valve further includes a shock-proof valve with an oil inlet connected to the internal pipeline M, and an oil outlet of the shock-proof valve is connected to the fuel tank.

[0016] The beneficial effect of adopting the above further scheme is that the shock-proof valve can effectively reduce the instantaneous pressure peak caused by operations such as sudden closing or commutation of valves in the hydraulic system, and achieve the protection effect on related components.

[0017] Further, the fluid filling valve further includes a logic valve with a lower oil inlet connected to the no-load starting valve, an upper oil inlet of the logic valve is connected to the fuel tank, and an oil outlet is connected to the bottom oil inlet e of the second priority valve.

[0018] The beneficial effect of adopting the above further scheme is that the logic valve can compare the pressures at its upper and lower oil inlets, input the larger pressure value to the second priority valve, and control the commutation of the second priority valve.

[0019] Further, the internal pipeline M is configured with a check valve, and an oil outlet of the check valve is connected to the suspension bridge control valve.

[0020] The beneficial effect of adopting the above further scheme is that the check valve can prevent the reverse flow of oil.

[0021] Further, a high-pressure fine filter valve is configured on the pipeline connecting the oil outlet of the gear pump and the oil inlet of the fluid filling valve group.

[0022] The beneficial effect of adopting the above further scheme is that the high-pressure fine filter valve can remove solid particle pollutants in the hydraulic oil, prevent impurities from entering these components, avoid component jamming, wear or functional failure caused by particle contamination, thereby extending the service life of the components and improving the reliability of the system.

[0023] Further, a branch pipeline is connected to the pipeline connecting the oil outlet of the gear pump and the oil inlet of the fluid filling valve group, the branch pipeline is configured with a first safety valve, and an oil outlet of the first safety valve is connected to the fuel tank.

[0024] The beneficial effect of adopting the above further scheme is that when the pressure in the system rises sharply and exceeds the set value, the first safety valve starts, allowing some oil to flow back from the high-pressure side to the fuel tank, thereby restricting the further increase of the system pressure and preventing the components in the hydraulic system from being damaged due to excessive pressure.

[0025] The present invention also provides a tractor, including the tractor suspension bridge control hydraulic system described above. Brief Description of the Drawings

[0026] Figure 1 It is a hydraulic system diagram of Embodiment 1 of the present invention; Figure 2 ForFigure 1 Partial structure diagram; Figure 3 This is the hydraulic system diagram of the second embodiment of the present invention, shown in the state where the engine is not started and the key is not powered on; Figure 4 is Figure 3 Partial enlarged view; Figure 5 This is the first partial structure of the second embodiment of the present invention, shown in the state where the engine is not started and the key is powered on; Figure 6 This is the second partial structure of the second embodiment of the present invention, shown in the state where the engine is started and there is no other action; Figure 7 This is the third partial structure of the second embodiment of the present invention, shown in the state where the engine is started, the no-load start valve is powered off, and the liquid filling starts; Figure 8 This is the fourth partial structure of the second embodiment of the present invention; Figure 9 It is the hydraulic system diagram of the tractor suspension bridge control in the related art.

[0027] In the drawings, the list of components represented by each reference numeral is as follows: 1. Fuel tank; 2. Suction filter; 3. Gear pump; 4. First safety valve; 5. High-pressure fine filter valve; 6. Suspension bridge control valve; 7. Left accumulator; 8. Left suspension bridge cylinder; 9. Right suspension bridge cylinder; 10. Right accumulator; 11. Tractor rear output multi-way valve and lift valve; 12. First priority valve group; 121. First priority valve; 122. Second safety valve; 13. Filling valve; 131. Second priority valve; 132. Filling pressure control valve; 133. No-load start valve; 134. Anti-shock valve; 135. Logic valve; 136. Check valve; 14. Accumulator. Detailed implementation manners

[0028] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0029] Embodiment 1 As Figures 1 to 8, the present invention provides a hydraulic control system for a tractor suspension bridge, which includes an oil tank 1, a gear pump 3, a suspension bridge control valve 6, a left suspension bridge cylinder 8, and a right suspension bridge cylinder 9. The inlet of the gear pump 3 is connected to the oil tank 1, and the outlet of the suspension bridge control valve 6 is simultaneously connected to the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9. It also includes a filling valve group, a tractor rear output multi-way valve, and a lift valve 11. The inlet of the filling valve group is connected to the outlet of the gear pump 3, and the filling valve group can be switched so that its outlet is connected to the inlet of the suspension bridge control valve 6 or to the inlet of the tractor rear output multi-way valve and the lift valve 11. The inlet of the tractor rear output multi-way valve and the lift valve 11 is connected to the oil tank 1.

[0030] The beneficial effect of this embodiment is that during the working state, the oil in the oil tank 1 is pumped by the gear pump 3 and input into the suspension bridge control valve 6 through the filling valve group, and then output to the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9, realizing the operation of the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9. During this oil supply process, when it is not necessary to continuously supply high-pressure oil to the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9, the oil pressure can be reduced, so that the filling valve group switches the oil port and supplies oil to the tractor rear output multi-way valve and the lift valve 11, and transports the oil tank 1 through the tractor rear output multi-way valve and the lift valve 11, realizing high-low pressure switching oil supply, and improving the technical problem that the gear pump 3 of the existing suspension bridge control hydraulic system has been working under high pressure, resulting in the hydraulic system heating up and even exceeding the operating temperature requirements of the oil product, affecting the normal operation of the hydraulic system.

[0031] Based on the above embodiment, a left accumulator 7 is connected to the pipeline where the suspension bridge control valve 6 is connected to the left suspension bridge cylinder 8, and a right accumulator 10 is connected to the pipeline where the suspension bridge control valve 6 is connected to the right suspension bridge cylinder 9.

[0032] Among them, a high-pressure fine filter valve 5 is arranged on the pipeline connecting the outlet of the gear pump 3 and the inlet of the filling valve group. In order to remove solid particle pollutants in the hydraulic oil through the high-pressure fine filter valve 5, prevent impurities from entering these components, avoid component jamming, wear or functional failure caused by particle contamination, thereby extending the service life of the components and improving the reliability of the system.

[0033] A branch pipeline is connected to the pipeline connecting the outlet of the gear pump 3 and the inlet of the filling valve group. The branch pipeline is equipped with a first safety valve 4, and the outlet of the first safety valve 4 is connected to the oil tank 1.

[0034] When the pressure in the system rises sharply and exceeds the set value, the first safety valve 4 is activated, so that part of the oil flows back from the high-pressure side to the oil tank 1, thereby limiting the further increase of the system pressure and preventing the components in the hydraulic system from being damaged due to excessive pressure.

[0035] Such as Figure 1 AndFigure 2 , as a first solution, the liquid filling valve group includes a first priority valve group 12. The first priority valve group 12 includes a first priority valve 121. The first priority valve 121 has an oil inlet a, a left oil outlet b, and a right oil outlet c. The first priority valve 121 can be switched to connect the oil inlet a and the left oil outlet b, or connect the oil inlet a and the right oil outlet c. The oil inlet a is connected to the oil outlet of the gear pump 3, and the left oil outlet b and the right oil outlet c are respectively connected to the oil inlet of the suspension bridge control valve 6 and the oil inlet of the rear output multi-way valve and lift valve 11 of the tractor.

[0036] The beneficial effect of adopting the preferred solution in the above embodiment is that in the working state, the oil in the fuel tank 1 is pumped by the gear pump 3. The first priority valve 121 is switched to connect the oil inlet a and the left oil outlet b, and is input into the suspension bridge control valve 6 through the first priority valve group 12, and then output to the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9, so as to realize the work of the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9. During this oil supply process, when it is not necessary to continuously supply high-pressure oil to the left suspension bridge cylinder 8 and the right suspension bridge cylinder 9, the first priority valve 121 can be switched to connect the oil inlet a and the right oil outlet c, and supply oil to the rear output multi-way valve and lift valve 11 of the tractor, and transport it to the fuel tank 1 through the rear output multi-way valve and lift valve 11 of the tractor, which can reduce the oil pressure, realize high-low pressure switching oil supply, and improve the technical problem that the gear pump 3 of the existing suspension bridge control hydraulic system has been working under high pressure, resulting in the hydraulic system heating up or even exceeding the use temperature requirement of the oil product, affecting the normal operation of the hydraulic system.

[0037] The first priority valve group 12 further includes a second safety valve 122. The oil inlet of the second safety valve 122 is connected to the first priority valve 121, and the oil outlet is connected to the fuel tank, so that part of the oil flows back from the high-pressure side to the fuel tank 1, thereby restricting the further increase of the system pressure and preventing the components in the hydraulic system from being damaged due to excessive pressure.

[0038] Embodiment 2 Such as Figures 3 to 8As a second solution, the difference between the second embodiment and the first embodiment is that the filling valve group includes a filling valve 13 provided with an oil inlet P and an oil outlet F1, the oil inlet P is connected to the oil outlet of the gear pump 3, the oil outlet F1 is connected to the oil inlet of the suspension bridge control valve 6, and the oil inlet P and the oil outlet F1 are connected through an internal pipe M, the filling valve 13 includes a second priority valve 131, a filling pressure control valve 132 and a no-load starting valve 133, the second priority valve 131 is provided with an upper oil inlet a and an upper oil outlet b connected to each other, a lower oil inlet c and a lower oil outlet d and a bottom oil inlet e which are disconnected from each other, and can be switched to connect the upper oil inlet a with the internal pipeline M, connect the upper oil outlet b with the oil inlet of the rear output multi-way valve of the tractor and the lifting valve 11, or switch to connect the lower oil inlet c with the internal pipeline M, and connect the lower oil outlet d with the oil inlet of the rear output multi-way valve of the tractor and the lifting valve 11; the filling pressure control valve 132 is provided with a connected The first left oil outlet a and the second left oil outlet b are connected, and the lower right oil outlet c and the right oil inlet d are disconnected, and the first left oil outlet a can be switched to be connected to the internal pipeline M, and the second left oil outlet b is connected to the pilot oil port of the filling pressure control valve 132, or the lower right oil outlet c is connected to the internal pipeline M, and the right oil inlet d is connected to the no-load starting valve 133; the no-load starting valve 133 is provided with an upper right oil outlet a and a first upper left oil outlet b that are connected, The disconnected lower closed oil port c and the first lower oil outlet d can be switched to the upper right oil outlet a to connect with the pilot oil port of the filling pressure control valve 132, or connected with the pilot oil port and the right oil inlet d of the filling pressure control valve 132 at the same time, and the first upper left oil outlet b is connected with the bottom oil inlet e of the second priority valve 131, or switched to the lower closed oil port c to connect with the pilot oil port of the filling pressure control valve 132, and the lower oil outlet d is connected with the bottom oil inlet e of the second priority valve 131.

[0039] The beneficial effect of adopting the preferred scheme in the above embodiment is that when working, the gear pump 3 inputs oil into the suspension bridge control valve 6 through the internal pipeline M to realize oil supply, and utilizes the second priority valve 131, the filling pressure control valve 132 and the no-load starting valve 133 to make the gear pump 3 standby at low pressure after oil supply, or output to the multi-way valve and the lifting valve 11 after the tractor, so as to avoid the gear pump 3 from frequently switching between high pressure and low pressure, thereby extending the service life of the gear pump 3.

[0040] The filling pressure control valve 132 is also provided with an upper right oil outlet e connected to its right oil inlet d, and an upper left oil outlet f which is disconnected from its first left oil outlet a and second left oil outlet b. The upper right oil outlet e and the upper left oil outlet f are both connected to the oil tank 1 through pipelines, and the upper left oil outlet f is in a sealed state.

[0041] The no-load starting valve 133 is also provided with a second upper left oil outlet e that is in a disconnected state from both its upper right oil outlet a and the first upper left oil outlet b, and a second lower oil outlet f that is in a connected state with its first lower oil outlet d. Both the second upper left oil outlet e and the second lower oil outlet f are connected to the fuel tank 1 through pipelines.

[0042] Specifically, during this process, as Figure 5 , when the no-load starting valve 133 is powered on, its valve core moves, and the connected pipelines will prepare for the no-load starting of the engine. The oil outlet of the gear pump 3 is in a state of no pressure or low pressure. At this time, the lower oil inlet c of the second priority valve 131 is connected to the internal pipeline M, and the lower oil outlet d of the second priority valve 131 is connected to the oil inlet of the rear output multi-way valve and the lift valve 11 of the tractor; the first left oil outlet a of the charge pressure control valve 132 is connected to the internal pipeline M, the second left oil outlet b of the charge pressure control valve 132 is connected to its pilot oil port, and the upper left oil outlet f of the charge pressure control valve 132 is connected to the fuel tank 1 through a pipeline. At this time, the upper left oil outlet f of the charge pressure control valve 132 is in a sealed state; and the first lower oil outlet d of the no-load starting valve 133 is connected to the second lower oil outlet f, the second lower oil outlet f of the no-load starting valve 133 is connected to the fuel tank 1 through a pipeline, the first lower oil outlet d is connected to the bottom oil inlet e of the second priority valve 131, and the lower closed oil port c of the no-load starting valve 133 is switched to be connected to the pilot oil port of the charge pressure control valve 132.

[0043] As Figure 6 , during the engine starting process and the first three seconds after starting, the system pressure is maintained at the spring setting value of the second priority valve 131 (usually very small, about 5 bar or less). At this time, the upper oil inlet a of the second priority valve 131 is connected to the internal pipeline M, and the upper oil outlet b is connected to the oil inlet of the rear output multi-way valve and the lift valve 11 of the tractor; the first left oil outlet a of the charge pressure control valve 132 is connected to the internal pipeline M, the second left oil outlet b of the charge pressure control valve 132 is connected to its pilot oil port, and the upper left oil outlet f of the charge pressure control valve 132 is connected to the fuel tank 1 through a pipeline. At this time, the upper left oil outlet f of the charge pressure control valve 132 is in a sealed state; and the first lower oil outlet d of the no-load starting valve 133 is connected to the second lower oil outlet f, the second lower oil outlet f of the no-load starting valve 133 is connected to the fuel tank 1 through a pipeline, the first lower oil outlet d is connected to the bottom oil inlet e of the second priority valve 131, and the lower closed oil port c of the no-load starting valve 133 is switched to be connected to the pilot oil port of the charge pressure control valve 132.

[0044] As Figure 7Three seconds after the engine starts, the no-load starting valve 133 will be powered off, and its valve core will move. The connected pipeline will prompt the second priority valve 131 to move in the closing direction. At this time, the oil in the gear pump 3 will be filled first, so that the oil pressure in the pipeline before the oil inlet of the suspension bridge control valve 6 and the suspension bridge control valve 6 will increase. At this time, the lower oil inlet c of the second priority valve 131 is connected to the internal pipeline M, and the lower oil outlet d of the second priority valve 131 is connected to the oil inlet of the tractor rear output multi-way valve and the lifting valve 11; the first left oil outlet a of the filling pressure control valve 132 is connected to the internal pipeline M, the second left oil outlet b is connected to its pilot oil port, and the upper left oil outlet f of the filling pressure control valve 132 is connected to the oil tank 1 through a pipeline. At this time, the upper left oil outlet f of the filling pressure control valve 132 is in a sealed state; and the upper right oil outlet a of the no-load start valve 133 is connected to the pilot oil port of the filling pressure control valve 132, the second upper left oil outlet e of the no-load start valve 133 is connected to the oil tank 1 through a pipeline, and the first upper left oil outlet b of the no-load start valve 133 is connected to the bottom oil inlet e of the second priority valve 131.

[0045] At this time, if Figure 8 Under the action of high pressure, the valve core of the filling pressure control valve 132 moves, and then the valve core of the second priority valve 131 moves. At this time, the gear pump 3 will be on standby under low pressure (or the working pressure of the output multi-way valve and the lifting valve 11 at the rear of the tractor). Such control avoids the frequent switching of the gear pump 3 between high pressure and low pressure, thereby extending the service life of the gear pump 3. At this time, the upper oil inlet a of the second priority valve 131 is connected to the internal pipeline M, and the upper oil outlet b is connected to the oil inlet of the tractor rear output multi-way valve and the lifting valve 11; the lower right oil outlet c of the filling pressure control valve 132 is connected to the internal pipeline M, and the lower right oil outlet c is in a sealed state, the right oil inlet d of the filling pressure control valve 132 is connected to the upper right oil outlet e, and the upper right oil outlet e is connected to the fuel tank 1; and the second upper left oil outlet e of the no-load starting valve 133 is connected to the fuel tank 1 through a pipeline, at this time, the second upper left oil outlet e is in a sealed state, the first upper left oil outlet b of the no-load starting valve 133 is connected to the bottom oil inlet e of the second priority valve 131, and the upper right oil outlet a of the no-load starting valve 133 is simultaneously connected to the pilot oil port and the right oil inlet d of the filling pressure control valve 132.

[0046] like Figures 3 to 8 On the basis of the above embodiment, the charging valve group further includes an accumulator 14 , and the accumulator 14 is connected to a pipeline between the oil outlet F1 of the charging valve 13 and the oil inlet of the suspension bridge control valve 6 .

[0047] The beneficial effect of adopting the preferred solution in the above-mentioned embodiment is that after the engine starts and the no-load start valve 133 is powered off, the connected pipeline causes the second priority valve 131 to move in the closing direction. At this time, the oil of the gear pump 3 will preferentially fill the accumulator 14 until the highest set pressure value is reached.

[0048] As Figures 3 to 8 , the filling valve 13 further includes a shock-proof valve 134 whose oil inlet is connected to the internal pipeline M, and the oil outlet of the shock-proof valve 134 is connected to the fuel tank 1.

[0049] The beneficial effect of adopting the preferred solution in the above-mentioned embodiment is that the shock-proof valve 134 can effectively reduce the instantaneous pressure peak caused by operations such as sudden closing or commutation of valves in the hydraulic system, and achieve the protection effect on related components.

[0050] As Figures 3 to 8 , the filling valve 13 further includes a logic valve 135 whose lower oil inlet is connected to the no-load start valve 133, the upper oil inlet of the logic valve 135 is connected to the fuel tank 1, and the oil outlet is connected to the bottom oil inlet e of the second priority valve 131.

[0051] The beneficial effect of adopting the preferred solution in the above-mentioned embodiment is that the logic valve 135 compares the pressures at its upper and lower oil inlets, inputs the larger pressure value to the second priority valve 131, and controls the commutation of the second priority valve 131.

[0052] As Figures 3 to 8 , the internal pipeline M is provided with a check valve 136, and the oil outlet of the check valve 136 is connected to the suspension bridge control valve 6.

[0053] The beneficial effect of adopting the preferred solution in the above-mentioned embodiment is that the check valve 136 can prevent the oil from flowing back.

[0054] Specifically, the outlet of the check valve 136 is connected to the oil outlet F1 of the filling valve 13, and the inlet is connected to the oil inlet P of the filling valve 13.

[0055] The present invention also provides a tractor, including the tractor suspension bridge control hydraulic system described in Embodiment 1 or Embodiment 2.

[0056] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", 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 device 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 of the present invention.

[0057] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. 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.

[0058] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. 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.

[0059] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0060] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", 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.

[0061] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydraulic control system for a tractor's floating axle, comprising an oil tank (1), a gear pump (3), a floating axle control valve (6), a left floating axle cylinder (8), and a right floating axle cylinder (9). The inlet of the gear pump (3) is connected to the oil tank (1), and the outlet of the floating axle control valve (6) is connected to both the left floating axle cylinder (8) and the right floating axle cylinder (9). It is characterized in that, It further includes a liquid filling valve group, a rear output multi-way valve of the tractor and a lift valve (11). The oil inlet of the liquid filling valve group is communicated with the oil outlet of the gear pump (3), and the liquid filling valve group can be switched to communicate its oil outlet with the oil inlet of the suspension bridge control valve (6) or with the oil inlet of the rear output multi-way valve and the lift valve (11) of the tractor. The oil inlet of the rear output multi-way valve and the lift valve (11) of the tractor is communicated with the fuel tank (1).

2. The hydraulic control system for the floating axle of a tractor according to claim 1, wherein The liquid filling valve group includes a first priority valve group (12). The first priority valve group (12) includes a first priority valve (121). The first priority valve (121) has an oil inlet a, a left oil outlet b and a right oil outlet c. The first priority valve (121) can be switched to communicate the oil inlet a with the left oil outlet b or the oil inlet a with the right oil outlet c. The oil inlet a is communicated with the oil outlet of the gear pump (3). The left oil outlet b and the right oil outlet c are respectively communicated with the oil inlet of the suspension bridge control valve (6) and the oil inlet of the rear output multi-way valve and the lift valve (11) of the tractor.

3. The hydraulic control system for the floating axle of a tractor according to claim 1, wherein The liquid filling valve group includes a liquid filling valve (13) provided with an oil inlet P port and an oil outlet F1 port. The oil inlet P port is communicated with the oil outlet of the gear pump (3), and the oil outlet F1 port is communicated with the oil inlet of the suspension bridge control valve (6). Moreover, the oil inlet P port and the oil outlet F1 port are communicated through an internal pipeline M. The liquid filling valve (13) includes a second priority valve (131), a liquid filling pressure control valve (132), and a no-load start valve (133). The second priority valve (131) is provided with an upper oil inlet a and an upper oil outlet b that are communicated, a lower oil inlet c and a lower oil outlet d that are disconnected, and a bottom oil inlet e. It can be switched so that the upper oil inlet a is communicated with the internal pipeline M, and the upper oil outlet b is communicated with the oil inlet of the rear output multi-way valve and lift valve (11) of the tractor, or switched so that the lower oil inlet c is communicated with the internal pipeline M, and the lower oil outlet d is communicated with the oil inlet of the rear output multi-way valve and lift valve (11) of the tractor; The liquid filling pressure control valve (132) is provided with a first left oil outlet a and a second left oil outlet b that are communicated, a lower right oil outlet c that is disconnected, and a right oil inlet d. It can be switched so that the first left oil outlet a is communicated with the internal pipeline M, and the second left oil outlet b is communicated with the pilot oil port of the liquid filling pressure control valve (132), or switched so that the lower right oil outlet c is communicated with the internal pipeline M, and the right oil inlet d is communicated with the no-load start valve (133); The no-load start valve (133) is provided with an upper right oil outlet a and a first upper left oil outlet b that are communicated, a lower closed oil port c and a first lower oil outlet d that are disconnected, and can be switched so that the upper right oil outlet a is communicated with the pilot oil port of the liquid filling pressure control valve (132), or simultaneously communicated with the pilot oil port and the right oil inlet d of the liquid filling pressure control valve (132), and the first upper left oil outlet b is communicated with the bottom oil inlet e of the second priority valve (131), or switched so that the lower closed oil port c is communicated with the pilot oil port of the liquid filling pressure control valve (132), and the lower oil outlet d is communicated with the bottom oil inlet e of the second priority valve (131).

4. The hydraulic control system for the floating axle of a tractor according to claim 3, wherein The liquid filling valve group further includes an accumulator (14), and the accumulator (14) is communicated with the pipeline between the oil outlet F1 port of the liquid filling valve (13) and the oil inlet of the suspension bridge control valve (6).

5. The hydraulic control system for the floating axle of a tractor according to claim 3, characterized in that, The liquid filling valve (13) further includes a shock-proof valve (134) whose oil inlet is communicated with the internal pipeline M, and the oil outlet of the shock-proof valve (134) is communicated with the fuel tank (1).

6. The hydraulic control system for the floating axle of a tractor according to claim 3, characterized in that, The liquid filling valve (13) further includes a logic valve (135) whose lower oil inlet is communicated with the no-load start valve (133), the upper oil inlet of the logic valve (135) is communicated with the fuel tank (1), and the oil outlet is communicated with the bottom oil inlet e of the second priority valve (131).

7. The hydraulic control system for the floating axle of a tractor according to claim 3, wherein The internal pipeline M is configured with a check valve (136), and the oil outlet of the check valve (136) is communicated with the suspension bridge control valve (6).

8. A hydraulic control system for a floating axle of a tractor according to any one of claims 1-7, characterized in that, The pipeline where the oil outlet of the gear pump (3) is communicated with the oil inlet of the liquid filling valve group is configured with a high-pressure fine filter valve (5).

9. A hydraulic control system for a floating axle of a tractor according to any one of claims 1-7, characterized in that, A pipeline connecting branch pipe that connects the oil outlet of the gear pump (3) and the oil inlet of the liquid filling valve group is provided with a first safety valve (4), and the oil outlet of the first safety valve (4) communicates with the fuel tank (1).

10. A tractor, characterized in that, It includes a tractor suspension bridge control hydraulic system according to any one of claims 1-9.

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