Speed-variable steering system for tractor and tractor with speed-variable steering system

Abstract

The utility model relates to a variable-rate steering system for a tractor and the tractor. The variable-rate steering system comprises an oil tank, a pump, a priority valve, a steering gear, a steering oil cylinder, a main valve and a confluence switching valve, an inlet of the pump is connected with the oil tank, an outlet of the pump is connected with an inlet of the priority valve, an oil outlet of the priority valve is connected with an oil inlet of the main valve and an oil inlet of the steering gear, and a left steering oil port of the steering gear is connected with a left cavity of the steering oil cylinder. A first oil port, a second oil port, a third oil port and a fourth oil port are formed in the main valve, the main valve is provided with an oil inlet and an oil return port, the confluence switching valve is provided with an oil port I, an oil port II, an oil port III and an oil port IV, the second oil port is communicated with the oil port I, the oil port II is connected with a left cavity of the steering oil cylinder, and the fourth oil port is connected with a right cavity of the steering oil cylinder. An oil return opening of the main valve is connected with the oil tank, and an oil return opening of the steering gear is connected with the oil tank. The method has the advantages that proper operation modes can be selected according to different operation working conditions, and the working efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of agricultural machinery equipment, in particular to a variable rate steering system for a tractor and a tractor with the same. Background Technique

[0002] Modern agricultural production is an important part of tractor mechanization. The age structure of tractor drivers has also changed. Young drivers pay more attention to driving comfort while improving work efficiency. The lightness and speed of the steering system will directly affect work efficiency and driving familiarity. In-depth research on it meets the strategic needs of national development.

[0003] At present, there are two forms of the tractor steering hydraulic system. The first is a steering system with a load feedback signal, and the second is a steering system without a load feedback signal. Neither form can meet the association between the maximum steering wheel turns and vehicle speed, that is, the maximum steering wheel turns need to be smaller at low speeds and larger at high speeds. During the tractor driving operation, regardless of the working conditions and vehicle speed, there is only one corresponding relationship between the steering angle of the steering wheel and the steering angle of the front axle. Considering driving safety, the steering wheel cannot be too sensitive when driving at high speed. That is to say, the number of turns of the steering wheel is a fixed value when the front axle of the tractor turns from the far right to the far left (generally between 2.5 and 5 turns, and usually the larger horsepower models take larger values). However, in some working conditions, the vehicle speed is very low and rapid steering is required. The number of turns is too many, which affects the driver's driving feeling, the work efficiency of the tractor is low, and the driver is prone to fatigue.

[0004] Based on this, it is necessary to develop a variable rate steering system for a tractor and a tractor with the same, which can enable the tractor to provide light and flexible steering at a slower speed and more firm steering at a higher speed. Content of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a variable rate steering system for a tractor and a tractor with the same, which effectively overcomes the defects of the prior art.

[0006] The technical solution of the utility model to solve the above technical problem is as follows:

[0007] A variable rate steering system for a tractor, comprising a fuel tank, a pump, a priority valve, a steering gear, a steering cylinder, a main valve and a confluence switching valve. The inlet of the pump is connected to the fuel tank through a pipeline, and the outlet of the pump is connected to the inlet of the priority valve through a pipeline. One oil outlet of the priority valve is connected to the oil inlet of the main valve and the oil inlet of the steering gear respectively through pipelines. The left steering oil port of the steering gear is connected to the left chamber of the steering cylinder through a pipeline, and the right steering oil port of the steering gear is connected to the right chamber of the steering cylinder through a pipeline. The main valve has a corresponding first oil port and second oil port and a corresponding third oil port and fourth oil port. The main valve has an oil inlet and an oil return port. The spool of the main valve can move to make the first oil port and the second oil port, the third oil port and the fourth oil port communicate or disconnect simultaneously, and make the oil inlet of the main valve communicate with the first oil port or the third oil port, and at the same time, the oil return port communicate with the third oil port or the first oil port. The confluence switching valve has a corresponding oil port I and oil port II and a corresponding oil port III and oil port IV. The spool of the confluence switching valve can move to make the oil port I and the oil port II, the oil port III and the oil port IV communicate or disconnect simultaneously. The second oil port is connected to the oil port I through a pipeline, the oil port II is connected to the left chamber of the steering cylinder through a pipeline, the oil port III is connected to the right chamber of the steering cylinder through a pipeline, the oil port IV is connected to the fourth oil port through a pipeline. The oil return port of the main valve is connected to the fuel tank through a pipeline, and the oil return port of the steering gear is connected to the fuel tank through a pipeline.

[0008] On the basis of the above technical solution, the present utility model can also be improved as follows.

[0009] Further, the priority valve is a two-way three-way valve.

[0010] Further, the other oil outlet of the priority valve is connected to the oil inlet of the multi-way valve through a pipeline, and the oil return port of the multi-way valve is connected to the fuel tank through a pipeline.

[0011] Further, the pump is a variable pump.

[0012] Further, the main valve is a three-position six-way solenoid valve.

[0013] Further, the main valve is electrically connected to an electro-hydraulic pilot control valve.

[0014] Further, the confluence switching valve is a solenoid valve.

[0015] Further, the confluence switching valve is electrically connected to an electro-hydraulic switching control valve.

[0016] Further, a filter is provided on the pipeline connecting the fuel tank and the pump.

[0017] The beneficial effects of the present utility model are as follows: The structure design is simple and reasonable. The driver can select a suitable operation mode according to different operation conditions, reducing the labor intensity of steering, improving work efficiency, enabling the tractor to provide a light and flexible steering at a relatively low speed and a more firm steering at a relatively high speed.

[0018] There is also provided a tractor, including a variable rate steering system for the tractor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. is a schematic structural view of the variable rate steering system for the tractor of the present utility model in the normal mode;

[0020] Figure 2 is Figure 1 an enlarged view of the structure of part A in

[0021] Figure 3 FIG. is a schematic structural view of the variable rate steering system for the tractor of the present utility model in the quick steering mode;

[0022] Figure 4 is Figure 3 an enlarged view of the structure of part B in

[0023] In the drawings, the list of components represented by each reference numeral is as follows:

[0024] 1, fuel tank; 2, pump; 3, priority valve; 4, steering gear; 5, steering cylinder; 6, main valve; 7, confluence switching valve; 8, multi-way valve; 9, electro-control pilot control valve; 10, electro-control switching control valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The principles and features of the present utility model will be described below with reference to the drawings. The examples given are only for explaining the present utility model and are not intended to limit the scope of the present utility model.

[0026] Embodiment 1

[0027] As Figure 1 , 2As shown in FIGS. 3 and 4, the variable rate steering system for a tractor in this embodiment includes an oil tank 1, a pump 2, a priority valve 3, a steering gear 4, a steering cylinder 5, a main valve 6, and a confluence switching valve 7. The inlet of the pump 2 is connected to the oil tank 1 through a pipeline, and the outlet of the pump 2 is connected to the inlet of the priority valve 3 through a pipeline. One oil outlet of the priority valve 3 is connected to the oil inlet of the main valve 6 and the oil inlet of the steering gear 4 through pipelines respectively. The left steering oil port of the steering gear 4 is connected to the left chamber of the steering cylinder 5 through a pipeline, and the right steering oil port of the steering gear 4 is connected to the right chamber of the steering cylinder 5 through a pipeline. The main valve 6 has a corresponding first oil port and second oil port, and a corresponding third oil port and fourth oil port. The main valve 6 has an oil inlet and an oil return port. The spool of the main valve 6 can move to make the first oil port and the second oil port, the third oil port and the fourth oil port communicate or disconnect simultaneously, and make the oil inlet of the main valve 6 communicate with the first oil port or the third oil port, and at the same time, the oil return port communicate with the third oil port or the first oil port. The confluence switching valve 7 has a corresponding oil port I and oil port II, and a corresponding oil port III and oil port IV. The spool of the confluence switching valve 7 can move to make the oil port I and the oil port II, the oil port III and the oil port IV communicate or disconnect simultaneously. The second oil port is connected to the oil port I through a pipeline, the oil port II is connected to the left chamber of the steering cylinder 5 through a pipeline, the oil port III is connected to the right chamber of the steering cylinder 5 through a pipeline, the oil port IV is connected to the fourth oil port through a pipeline, the oil return port of the main valve 6 is connected to the oil tank 1 through a pipeline, and the oil return port of the steering gear 4 is connected to the oil tank 1 through a pipeline.

[0028] The variable rate steering system for a tractor in this embodiment has the following two modes:

[0029] 1) Normal mode: The passage between the main valve 6 and the confluence switching valve 7 is cut off. The pump 2 pumps the oil in the oil tank 1 to the priority valve 3, and then transports it to the steering gear 4 through the priority valve 3. Just operate the steering gear 4 to turn normally. For example, when turning left, the left steering oil port of the steering gear 4 communicates with the left chamber of the steering cylinder 5, and the oil enters the left chamber of the steering cylinder 5. The oil in the right chamber of the steering cylinder 5 flows back to the oil return port of the steering gear 4 through the right steering oil port and then back to the oil tank 1. Similarly, when turning right, the right steering oil port of the steering gear 4 communicates with the right chamber of the steering cylinder 5 to supply oil, and the oil enters the right chamber of the steering cylinder 5. The oil in the left chamber of the steering cylinder 5 flows back to the oil return port of the steering gear 4 through the left steering oil port of the steering gear 4 and then back to the oil tank 1.

[0030] 2) Quick steering mode: The passage between the main valve 6 and the confluence switching valve 7 is unobstructed. The pump 2 pumps the oil in the fuel tank 1 to the priority valve 3, which delivers it to the steering gear 4. Before flowing into the steering gear 4, the oil is diverted. Part of it enters the steering gear 4, and part is output through the main valve 6 and the confluence switching valve 7, and converges with the oil coming out of the left or right steering oil port of the steering gear 4 to enter the left or right chamber of the steering cylinder 5, that is, the two parts of oil are combined to supply the action of the steering cylinder 5 to achieve quick steering.

[0031] More specifically, during left steering, the oil entering the main valve 6 passes through the first oil port - the second oil port - the oil port I - the oil port II - and combines with the oil coming out of the left steering oil port of the steering gear 4 to enter the left chamber of the steering cylinder 5 together. The right chamber of the steering cylinder 5 and the right working oil port of the steering gear 4 are combined - the oil port III - the oil port IV - the fourth oil port - the third oil port - the fuel tank 1; Similarly, during right steering, the oil entering the main valve 6 passes through the third oil port - the fourth oil port - the oil port IV - the oil port III - and combines with the oil coming out of the right steering oil port of the steering gear 4 to enter the right chamber of the steering cylinder 5 together. The left chamber of the steering cylinder 5 and the left working oil port of the steering gear 4 are combined - the oil port II - the oil port I - the second oil port - the first oil port - the fuel tank 1. Overall, the structural design is simple and reasonable. The driver can select the appropriate operating mode according to different operating conditions, reduce the labor intensity of steering, improve work efficiency, enable the tractor to provide light and flexible steering at a slower speed, and provide more firm steering at a higher speed.

[0032] In this embodiment, the above-mentioned priority valve 3 adopts a conventional existing technology product: a two-position three-way valve. The specific model is reasonably selected according to the actual working requirements and will not be elaborated here.

[0033] As a preferred implementation manner, another oil outlet of the above-mentioned priority valve 3 is connected to the oil inlet of the multi-way valve 8 through a pipeline, and the oil return port of the multi-way valve 8 is connected to the above-mentioned fuel tank 1 through a pipeline.

[0034] In the above-mentioned implementation scheme, the multi-way valve 8 or the steering gear 4 can be supplied with oil by adjusting the priority valve 3. When supplying oil to the multi-way valve 8, the working oil ports of the multi-way valve 8 are respectively connected to other hydraulic devices (or pipelines).

[0035] In this embodiment, the above-mentioned pump 2 adopts a variable pump of an adapted model in the prior art, and its specific structure and principle will not be elaborated here.

[0036] In this implementation, the above-mentioned main valve 6 adopts a three-position six-way solenoid valve of an adapted model in the prior art, and its specific structure and principle will not be elaborated here.

[0037] In this embodiment, the above-mentioned main valve 6 is electrically connected to the electro-hydraulic pilot control valve 9. The electro-hydraulic pilot control valve 9 is used to control the main valve 6 to be energized or de-energized.

[0038] In this embodiment, the above-mentioned confluence switching valve 7 adopts a solenoid valve of an adapted model in the prior art, and its specific structure and principle will not be elaborated here.

[0039] In this embodiment, the above-mentioned confluence switching valve 7 is electrically connected to the electric control switching control valve 10. The electric control pilot control valve 9 is used to control the energization or de-energization of the confluence switching valve 7.

[0040] In this embodiment, a filter is provided on the pipeline connecting the above-mentioned fuel tank 1 and the pump 2. The oil entering the pipeline is filtered to prevent impurities from entering. The above-mentioned filter can adopt existing products on the market for filtering the oil circuit in the hydraulic pipeline, and can be flexibly adapted and selected according to actual needs.

[0041] Embodiment 2

[0042] The tractor of this embodiment includes the variable rate steering system for tractors in Embodiment 1.

[0043] In the description of the present invention, it should be understood that 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. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are 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 cannot be construed as a limitation of the present invention.

[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating 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, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0045] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected", "fixed", etc. should 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 can 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.

[0046] In the present utility model, unless otherwise clearly stipulated and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the horizontal height of the first feature is less than that of the second feature.

[0047] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean 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 utility model. 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 a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0048] Although the embodiments of the present utility model 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 utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A variable speed steering system for a tractor, characterized in that: The invention comprises an oil tank (1), a pump (2), a priority valve (3), a steering gear (4), a steering oil cylinder (5), a main valve (6) and a confluence switching valve (7), wherein the inlet of the pump (2) is connected to the oil tank (1) through a pipeline, the outlet of the pump (2) is connected to the inlet of the priority valve (3) through a pipeline, an oil outlet of the priority valve (3) is respectively connected to the oil inlet of the main valve (6) and the oil inlet of the steering gear (4) through pipelines, the left steering oil port of the steering gear (4) is connected to the left chamber of the steering oil cylinder (5) through a pipeline, the right steering oil port of the steering gear (4) is connected to the right chamber of the steering oil cylinder (5) through a pipeline, the main valve (6) has a first oil port and a second oil port corresponding to each other and a third oil port and a fourth oil port corresponding to each other, the main valve (6) has an oil inlet and an oil return port, and the valve core of the main valve (6) can be moved to the first oil port and the third oil port. The second oil port, the third oil port and the fourth oil port are connected or disconnected at the same time, and the oil inlet of the main valve (6) is connected to the first oil port or the third oil port, and the oil return port is connected to the third oil port or the first oil port. The confluence switching valve (7) has oil ports I and II corresponding to each other and oil ports III and IV corresponding to each other. The valve core of the confluence switching valve (7) can be moved to the point where the oil ports I and II, and the oil ports III and IV are connected or disconnected at the same time. The second oil port is connected to the oil port I through a pipeline, the oil port II is connected to the left chamber of the steering cylinder (5) through a pipeline, the oil port III is connected to the right chamber of the steering cylinder (5) through a pipeline, the oil port IV is connected to the fourth oil port through a pipeline, the oil return port of the main valve (6) is connected to the oil tank (1) through a pipeline, and the oil return port of the steering gear (4) is connected to the oil tank (1) through a pipeline.

2. A variable speed steering system for a tractor according to claim 1, characterized in that: The priority valve (3) is a two-position three-way valve.

3. A variable speed steering system for a tractor according to claim 2, characterized in that: Another oil outlet of the priority valve (3) is connected to the oil inlet of the multi-way valve (8) through a pipeline, and the oil return port of the multi-way valve (8) is connected to the oil tank (1) through a pipeline.

4. A variable rate steering system for a tractor according to claim 1, characterized in that: The pump (2) is a variable displacement pump.

5. A variable rate steering system for a tractor according to claim 1, characterized in that: The main valve (6) is a three-position six-way solenoid valve.

6. A variable speed steering system for a tractor according to claim 5, characterized in that: The main valve (6) is electrically connected to the electric pilot control valve (9).

7. A variable rate steering system for a tractor according to claim 1, characterized in that: The confluence switching valve (7) is a solenoid valve.

8. A variable rate steering system for a tractor according to claim 7, characterized in that: The confluence switching valve (7) is electrically connected to the electrically controlled switching control valve (10).

9. A variable rate steering system for a tractor according to any one of claims 1 to 8, characterized in that: A filter is provided on the pipeline connecting the oil tank (1) and the pump (2).

10. A tractor, characterized in that: A variable rate steering system for a tractor comprising the variable rate steering system as claimed in any one of claims 1 to 9.

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