Waist twisting and bowing double-joint steering device of tractor

Abstract

The utility model belongs to the technical field of mechanical equipment, and particularly relates to a tractor waist twisting and bowing double-joint steering device which comprises a waist twisting joint assembly, a bowing joint assembly, a torsion spring assembly, a hydraulic driving assembly and a cooperative control assembly. The waist twisting joint assembly comprises a waist twisting shell and a front bowing shell which are coaxially arranged, the waist twisting shell and the front bowing shell are nested and matched in a sleeving manner, and the waist twisting shell and the front bowing shell can relatively rotate around the central axis of the waist twisting shell. In the steering process of the bowing tractor, asymmetric driving force is applied to the front bowing shell through the first multi-stage hydraulic oil cylinder and the second multi-stage hydraulic oil cylinder, accurate bowing steering of a vehicle can be achieved, the phenomena of tire slipping and traction force loss are avoided, the torsion load of a vehicle body can be absorbed through the torsion spring assembly, and therefore the bowing tractor is more stable in steering. And cracking deformation caused by rigid collision between the elements is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical equipment technology, specifically relating to a tractor twisting and bending double joint steering device. Background Technology

[0002] In agricultural production, articulated tractors, as important power machinery, are widely used in field operations and transportation. The steering system is a key component of articulated tractors, and its performance directly affects the tractor's operational flexibility, driving stability, and work efficiency. Traditional articulated tractor steering systems achieve steering through a single articulated joint, which is generally sufficient for use on normal, flat roads.

[0003] However, when operating in complex and rugged terrain, the traditional articulated scissor tractor steering system reveals many technical defects. The rigid articulated structure cannot dynamically compensate for height differences caused by road undulations, leading to frequent wheel lift-offs. This not only interrupts power transmission and reduces traction, lowering work efficiency, but also significantly increases the risk of rollover during hill turns, threatening operational safety. Existing technologies, such as the articulated steering mechanism for scissor tractors disclosed in patent publication number CN213442766U, employ a rigid impact limiting structure, which is prone to shell cracking and deformation under impact loads, shortening the equipment's service life. Another example is the scissor-twisting device for hilly and mountainous scissor tractors disclosed in patent publication number CN116834545A, whose twisting function is passive, potentially causing uncontrolled swaying of the front housing during complex slope operations, severely affecting driving stability.

[0004] In summary, while current folding tractor steering systems can constrain the twisting and bending angles to some extent, the lack of effective dynamic coordination between the control system and the mechanical structure makes it impossible to simultaneously solve the problems of poor wheel contact and insufficient steering stability, thus failing to meet the operational needs in complex terrains. Based on the above problems, this application proposes a tractor twisting and bending dual-joint steering device to improve these issues. Utility Model Content

[0005] The purpose of this utility model is to provide a tractor twisting and bending double joint steering device. During the bending tractor steering process, the first multi-stage hydraulic cylinder and the second multi-stage hydraulic cylinder apply asymmetrical driving force to the front bending housing respectively, so that the vehicle can achieve precise bending steering and avoid tire slippage and loss of traction. It can also absorb the torsional load of the vehicle body through the torsion spring assembly and avoid cracking and deformation caused by rigid collision between components.

[0006] The specific technical solution adopted by this utility model is as follows:

[0007] A tractor with a twisting and bending dual-joint steering device includes: a twisting joint assembly, a bending joint assembly, a torsion spring assembly, a hydraulic drive assembly, and a cooperative control assembly;

[0008] The twisting joint assembly includes a twisting housing and a front folding housing arranged coaxially. The twisting housing and the front folding housing are nested together in a sleeve manner, and the twisting housing and the front folding housing can rotate relative to each other around the central axis of the twisting housing.

[0009] The folding joint assembly includes a T-shaped pin and a rear folding housing. The T-shaped pin is rotatably connected to the end of the front folding housing away from the twisting housing. The rear folding housing is rotatably connected to the outside of the T-shaped pin, and the rear folding housing can rotate around the central axis of the T-shaped pin.

[0010] The hydraulic drive assembly is assembled between the front folding housing and the rear folding housing, and the hydraulic drive assembly is configured to drive relative rotation between the folding joint assembly and the twisting joint assembly.

[0011] The torsion spring assembly is assembled between the torsion waist housing and the front folding waist housing. The torsion spring assembly is configured to autonomously perform compression / reset actions according to changes in ground energy, and to trigger a stiffness mutation to achieve limit when the torsion angle reaches a threshold.

[0012] The collaborative control component is connected to the hydraulic drive component, and the collaborative control component is configured to drive the hydraulic drive component to operate.

[0013] During the turning process of the tractor, the hydraulic drive assembly can apply an asymmetrical driving force to the torsion joint assembly, and the torsion spring assembly can absorb the torsional load of the vehicle body.

[0014] In a preferred embodiment, the hydraulic drive assembly includes a first multi-stage hydraulic cylinder and a second multi-stage hydraulic cylinder, both of which are rotatably connected to the outside of the rear folding housing, and the front folding housing and the output ends of the first multi-stage hydraulic cylinder, as well as the output ends of the front folding housing and the second multi-stage hydraulic cylinder, are rotatably connected.

[0015] In a preferred embodiment, the torsion spring assembly includes a first torsion spring and a second torsion spring. Both the first and second torsion springs are assembled between the torsion waist housing and the front folding waist housing and are located outside the front folding waist housing. In the initial state, both the first and second torsion springs are in a free state. The first torsion spring is configured to trigger a stiffness mutation to limit the torsion waist housing and the front folding waist housing when the torsion angle reaches an upper limit threshold and the torsion waist housing rotates in the forward direction relative to the front folding waist housing, and the second torsion spring is in a free state. The second torsion spring is configured to trigger a stiffness mutation to limit the torsion waist housing and the front folding waist housing when the torsion waist housing rotates in the reverse direction relative to the front folding waist housing and the torsion angle reaches a lower limit threshold, and the first torsion spring is in a free state.

[0016] In a preferred embodiment, the inner wall of the front folding housing is provided with multiple positioning bosses, and the positioning bosses are provided with slots. The ends of the first torsion spring and the second torsion spring that are close to each other are respectively adapted to the multiple slots on the outer side of the folding housing, and the ends of the first torsion spring and the second torsion spring that are far from each other are respectively adapted to the multiple slots on the inner wall of the front folding housing.

[0017] In a preferred embodiment, the cooperative control component includes a steering wheel and a steering gear, with the input ends of the steering wheel and the steering gear fixedly connected. A proportional valve controller is integrated on the outside of the steering gear, and the proportional valve controller has a first output end and a second output end. One second multi-stage hydraulic cylinder is connected to the first output end via a first oil pipe, and another second multi-stage hydraulic cylinder is connected to the second output end via a second oil pipe. The first output end, the first oil pipe, and the second multi-stage hydraulic cylinder connected to the first oil pipe constitute a first oil circuit, and the second output end, the second oil pipe, and the second multi-stage hydraulic cylinder connected to the second oil pipe constitute a second oil circuit. The proportional valve controller is configured to adjust the flow ratio of the first oil circuit and the second oil circuit after the steering gear obtains the rotation angle of the steering wheel.

[0018] In a preferred embodiment, a limit block is provided on the outer side of the front folding housing, and a braking block is provided on the outer side of the twisting housing, and the limit block and the braking block are adapted to each other.

[0019] In a preferred embodiment, a first stepped bushing and a second stepped bushing are fitted between the twisted waist housing and the front folding waist housing, and the first stepped bushing and the second stepped bushing are respectively located at both ends inside the front folding waist housing.

[0020] The technical effects achieved by this utility model are as follows:

[0021] In the process of turning a folding tractor, this utility model obtains the rotation angle of the steering wheel through the steering gear. The proportional valve controller adjusts the flow ratio of the first oil circuit and the second oil circuit according to the rotation angle of the steering wheel, so that the first multi-stage hydraulic cylinder and the second multi-stage hydraulic cylinder apply asymmetrical driving force to the front folding housing respectively. The vehicle can achieve precise folding steering, and at the same time, it can avoid the phenomenon of tire slippage and loss of traction during vehicle driving.

[0022] When the wheels of the folding tractor lift off the ground while traveling on rough roads or turning, the interaction between the gravitational torque and the ground reaction force drives the folding housing to rotate relative to the front folding housing. After the folding housing rotates, it causes the first or second torsion spring to contract and absorb the torsional load of the vehicle body. When the folding housing rotates relative to the front folding housing and the torsion angle reaches the upper or lower threshold, it triggers a sudden change in the stiffness of the first or second torsion spring, locking the maximum torsion angle of the folding housing relative to the front folding housing. This avoids cracking and deformation caused by rigid collisions between components, effectively improving the service life of the device. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0024] Figure 2 This is a partial top view of the structure of this utility model;

[0025] Figure 3 This is a sectional view of a partial structure of this utility model;

[0026] Figure 4 This is a schematic diagram of the structure of the twisted housing of this utility model.

[0027] The attached diagram lists the components represented by each number as follows:

[0028] 1. Twisting waist housing; 2. First step bushing; 3. Front folding waist housing; 4. First multi-stage hydraulic cylinder; 5. Second step bushing; 6. Limiting shim; 7. First shim; 8. T-pin; 9. Second shim; 10. Rear folding waist housing; 11. Steering wheel; 12. Steering gear; 13. First oil pipe; 14. Second oil pipe; 15. Second multi-stage hydraulic cylinder; 16. First torsion spring; 17. Second torsion spring; 18. Limiting block; 19. Brake block. Detailed Implementation

[0029] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0032] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0033] Please see the appendix Figures 1 to 4 As shown, this is the first embodiment of the present invention. This embodiment provides a tractor twisting and bending double joint steering device, which is suitable for bending tractor equipment and includes: a twisting joint assembly, a bending joint assembly, a torsion spring assembly, a hydraulic drive assembly, and a cooperative control assembly.

[0034] The twisting joint assembly includes a twisting housing 1 and a front folding housing 3 arranged coaxially. The twisting housing 1 is a hollow cylindrical structure with a flange, and the front folding housing 3 is also a hollow cylindrical structure. The twisting housing 1 and the front folding housing 3 are nested together in a sleeve manner, with a clearance fit between them. The twisting housing 1 and the front folding housing 3 can rotate relative to each other around the central axis of the twisting housing 1.

[0035] The waist-folding joint assembly includes a T-shaped pin 8 and a rear waist-folding housing 10. The T-shaped pin 8 is rotatably connected to the end of the front waist-folding housing 3 away from the waist-twisting housing 1, and the rear waist-folding housing 10 is rotatably connected to the outside of the T-shaped pin 8. The rear waist-folding housing 10 can rotate around the central axis of the T-shaped pin 8.

[0036] The hydraulic drive assembly is assembled between the front folding housing 3 and the rear folding housing 10. The hydraulic drive assembly is configured to drive relative rotation between the folding joint assembly and the twisting joint assembly.

[0037] The torsion spring assembly is assembled between the torsion waist housing 1 and the front folding waist housing 3. The torsion spring assembly is configured to autonomously perform compression / reset actions according to changes in ground energy, and trigger a sudden stiffness change to achieve limit when the torsion angle reaches a threshold.

[0038] The cooperative control component is installed in the cab of the articulated tractor. The cooperative control component is connected to the hydraulic drive component. The cooperative control component is configured to drive the hydraulic drive component and also to control the direction of travel of the articulated tractor.

[0039] In the process of turning the tractor, the hydraulic drive component can apply an asymmetrical driving force to the torsion joint component, and the torsion spring component can absorb the torsional load of the vehicle body.

[0040] Here, an oil supply module is used in conjunction with the collaborative control component. The collaborative control component can control the oil supply module to deliver / recover pressurized oil to the hydraulic drive component. The oil supply module is an existing mature application, and its specific structure and working process can be found in the prior art. It will not be described in detail here.

[0041] It should be noted that this device is applicable to articulated tractors (hereinafter referred to as vehicles), and the articulated housing 1 is fixedly connected to the front axle of the articulated tractor, and the rear articulated housing 10 is fixedly connected to the rear axle of the articulated tractor. Other parts and modules in the articulated tractor are not described in detail in this application. For the undescribed parts, modules and related working principles, please refer to the prior art. Further details will not be provided here.

[0042] Furthermore, the front folding housing 3 has two symmetrically arranged first hinge ears at one end near the rear folding housing 10, and the rear folding housing 10 has two symmetrically arranged second hinge ears at one end near the front folding housing 3. The first and second hinge ears correspond one-to-one, and a first washer 7 is fitted between the corresponding first and second hinge ears. The T-shaped pin 8 is rotatably connected to the inside of the corresponding first and second hinge ears, and a second washer 9 is fixed inside the second hinge ear. The second washer 9 is adapted to the T-shaped pin 8 and is used to limit the movement of the T-shaped pin 8.

[0043] In this embodiment, the driver controls and adjusts the vehicle's direction of travel through the cooperative control component. When the driver controls the vehicle to steer through the cooperative control component, the cooperative control component drives the hydraulic drive component to operate. The hydraulic drive component drives the torsion joint component to rotate relative to the rear folding shell 10, causing the vehicle to fold and steer. During the steering process, the hydraulic drive component applies an asymmetrical driving force to the torsion joint component, which can effectively prevent tire slippage and traction loss during vehicle travel. When the vehicle is traveling on rough roads or when turning, causing the wheels to lift off the ground, the interaction between the gravitational torque and the ground reaction force drives the torsion shell 1 and the front folding shell 3 to twist around the central axis of the torsion shell 1, ensuring that the lifted wheels quickly land and regain traction. During this process, the torsion spring component can absorb the torsional load of the vehicle body, thereby suppressing the risk of roll during vehicle steering.

[0044] Secondly, please refer to again Figures 1 to 2 As shown, the hydraulic drive assembly includes a first multi-stage hydraulic cylinder 4 and a second multi-stage hydraulic cylinder 15. Both the first multi-stage hydraulic cylinder 4 and the second multi-stage hydraulic cylinder 15 are rotatably connected to the outside of the rear folding housing 10, and the output ends of the front folding housing 3 and the first multi-stage hydraulic cylinder 4, as well as the output ends of the front folding housing 3 and the second multi-stage hydraulic cylinder 15, are rotatably connected.

[0045] It should be noted that the outer side of the front folding housing 3 is symmetrically provided with a first earring seat and a second earring seat, and the outer side of the rear folding housing 10 is symmetrically provided with a third earring seat and a fourth earring seat. The first earring seat and the third earring seat, as well as the second earring seat and the fourth earring seat, are all mutually compatible. Furthermore, the first earring seat and the output end (i.e., piston rod) of the first multi-stage hydraulic cylinder 4, the third earring seat and the end (i.e., base) of the first multi-stage hydraulic cylinder 4, the second earring seat and the output end of the second multi-stage hydraulic cylinder 15, and the fourth earring seat and the end of the second multi-stage hydraulic cylinder 15 are all rotatably connected.

[0046] In this embodiment, the driver controls and adjusts the vehicle's direction of travel through the collaborative control component. When the driver controls the vehicle to turn left through the collaborative control component, the component drives the oil supply module to operate, supplying pressurized oil to the first multi-stage hydraulic cylinder 4. This causes the piston rod of the first multi-stage hydraulic cylinder 4 to extend outward, pushing the front folding housing 3 to rotate around the central axis of the T-shaped pin 8. This causes the front folding housing 3 to rotate relative to the rear folding housing 10. Simultaneously, the oil supply module... The system synchronously recovers the pressure oil inside the second multi-stage hydraulic cylinder 15, causing the piston rod of the second multi-stage hydraulic cylinder 15 to retract inward. The piston rod of the second multi-stage hydraulic cylinder 15 pulls the front folding housing 3 to rotate around the central axis of the T-shaped pin shaft 8. Through the cooperation of the first multi-stage hydraulic cylinder 4 and the second multi-stage hydraulic cylinder 15, a compound stroke is formed, so that the device synchronously drives the front folding housing 3 to rotate relative to the rear folding housing 10 through asymmetrical driving force, thereby avoiding tire slippage and traction loss during vehicle operation.

[0047] Secondly, please refer to the following as well. Figure 3 and Figure 4 The torsion spring assembly includes a first torsion spring 16 and a second torsion spring 17. Both the first torsion spring 16 and the second torsion spring 17 are assembled between the torsion waist housing 1 and the front folding waist housing 3 and are located outside the front folding waist housing 3. In the initial state, both the first torsion spring 16 and the second torsion spring 17 are in a free state. The first torsion spring 16 is configured to trigger a stiffness change to limit the torsion waist housing 1 and the front folding waist housing 3 when the torsion waist housing 1 rotates in the forward direction relative to the front folding waist housing 3 and the torsion angle reaches the upper limit threshold. At this time, the second torsion spring 17 is in a free state. The second torsion spring 17 is configured to trigger a stiffness change to limit the torsion waist housing 1 and the front folding waist housing 3 when the torsion waist housing 1 rotates in the reverse direction relative to the front folding waist housing 3 and the torsion angle reaches the lower limit threshold. At this time, the first torsion spring 16 is in a free state.

[0048] Here, the inner wall of the front folding housing 3 is provided with multiple positioning bosses, and the inside of the positioning bosses is provided with slots. The ends of the first torsion spring 16 and the second torsion spring 17 that are close to each other are respectively adapted to the multiple slots on the outside of the folding housing 1, and the ends of the first torsion spring 16 and the second torsion spring 17 that are far from each other are respectively adapted to the multiple slots on the inner wall of the front folding housing 3. The cross-sectional shape of the slots on the horizontal projection plane is L-shaped, and the opening directions of the two L-shaped slots are opposite.

[0049] Furthermore, the two ends of the first torsion spring 16 and the second torsion spring 17 are respectively referred to as the fixed end and the movable end. The fixed end of the first torsion spring 16 and the torsion waist housing 1, as well as the fixed end of the second torsion spring 17 and the torsion waist housing 1, are fixedly connected. The movable end of the first torsion spring 16 and the slot, as well as the movable end of the second torsion spring 17 and the slot, are mutually adapted. When the torsion waist housing 1 rotates forward relative to the front folding waist housing 3, the slot limits the movable end of the first torsion spring 16. After the torsion waist housing 1 rotates, it drives the first torsion spring 16 to rotate. When the fixed end of spring 16 rotates, the first torsion spring 16 contracts. At this time, the slot does not limit the movable end of the second torsion spring 17, and the second torsion spring 17 is in a free state. When the waist-twisting housing 1 rotates in the opposite direction to the front waist-folding housing 3, the slot limits the movable end of the second torsion spring 17. After the waist-twisting housing 1 rotates, it drives the fixed end of the second torsion spring 17 to rotate, causing the second torsion spring 17 to contract. At this time, the slot does not limit the movable end of the first torsion spring 16, and the first torsion spring 16 is in a free state.

[0050] It should be noted that, in order for those skilled in the art to better understand the working process of this device, forward rotation is defined as clockwise rotation of the torsion waist shell 1 relative to the front folding waist shell 3, and reverse rotation is defined as counterclockwise rotation of the torsion waist shell 1 relative to the front folding waist shell 3. However, the above definitions are only for distinguishing the direction of rotation of the torsion waist shell 1 relative to the front folding waist shell 3 and do not constitute a specific limitation. The upper threshold represents the maximum angle when the torsion waist shell 1 rotates clockwise relative to the front folding waist shell 3; the lower threshold represents the maximum angle when the torsion waist shell 1 rotates counterclockwise relative to the front folding waist shell 3, and the absolute values ​​of the upper threshold and the lower threshold are equal.

[0051] In this embodiment, when the vehicle is traveling on rough roads or turning, causing the wheels to lift off the ground, the interaction between the gravitational torque and the ground reaction force drives the torsional housing 1 to rotate relative to the front folding housing 3. After the torsional housing 1 rotates, it causes the first torsion spring 16 or the second torsion spring 17 to contract. When the torsional housing 1 rotates relative to the front folding housing 3 and the torsion angle reaches the upper or lower threshold, it triggers a sudden change in the stiffness of the first torsion spring 16 or the second torsion spring 17. The first torsion spring 16 or the second torsion spring 17 limits the torsional housing 1 and the front folding housing 3, locking the maximum torsion angle of the torsional housing 1 relative to the front folding housing 3. When the vehicle returns to a level position... After the vehicle has stabilized, the first torsion spring 16 or the second torsion spring 17, which is in a contracted state, releases its elastic potential energy to drive the torsion waist housing 1 to reset, so that the torsion waist joint returns to its initial state. Through the above technical solution, when the vehicle is driving on rough roads or when the wheels are off the ground, the torsion waist housing 1 compresses the first torsion spring 16 or the second torsion spring 17, and the first torsion spring 16 or the second torsion spring 17 buffers the sudden torsion of the torsion waist housing 1, absorbs the torsional load of the vehicle body, and avoids the cracking and deformation of components caused by rigid collisions, effectively improving the service life of the device. At the same time, the synergistic effect of the hydraulic drive component and the torsion spring component suppresses the risk of roll when the vehicle is turning.

[0052] In one specific embodiment, when the vehicle is traveling on a rough road or when turning causes the right front wheel to lift off the ground, the vehicle's gravitational torque forces the torsion waist shell 1 to twist clockwise relative to the front folding waist shell 3. The first torsion spring 16 is compressed and undergoes elastic deformation, storing elastic potential energy. The second torsion spring 17 is circumferentially displaced within the front folding waist shell 3, in a free state with no torque output. When the torsion angle of the torsion waist shell 1 relative to the front folding waist shell 3 reaches the upper limit threshold, the stiffness of the first torsion spring 16 suddenly locks, locking at the maximum clockwise torsion angle. The first torsion spring 16 absorbs the torsional load of the vehicle body, and in conjunction with the hydraulic drive components, suppresses the risk of roll during vehicle turning. When the road surface is flat, the first torsion spring 16 releases potential energy to drive the torsion waist joint back to center. The first torsion spring 16 buffers the sudden torsion, avoiding rigid collisions.

[0053] Please refer to it again. Figure 1The collaborative control component includes a steering wheel 11 and a steering gear 12. The input ends of the steering wheel 11 and the steering gear 12 are fixedly connected. A proportional valve controller is integrated on the outside of the steering gear 12. The proportional valve controller has a first output end and a second output end. A second multi-stage hydraulic cylinder 15 is connected to the first output end through a first oil pipe 13. Another second multi-stage hydraulic cylinder 15 is connected to the second output end through a second oil pipe 14. The first output end, the first oil pipe 13, and the second multi-stage hydraulic cylinder 15 connected to the first oil pipe 13 constitute a first oil circuit. The second output end, the second oil pipe 14, and the second multi-stage hydraulic cylinder 15 connected to the second oil pipe 14 constitute a second oil circuit. The proportional valve controller is configured to adjust the flow ratio of the first oil circuit and the second oil circuit after the steering gear 12 obtains the rotation angle of the steering wheel 11.

[0054] Here, the input terminals of the oil supply module and the proportional valve controller are connected by pipelines.

[0055] In this embodiment, during vehicle operation, the driver adjusts and controls the vehicle's forward direction via the steering wheel 11, obtains the rotation angle of the steering wheel 11 via the steering gear 12, and the proportional valve controller adjusts the flow ratio of the first and second oil circuits according to the rotation angle of the steering wheel 11, so that the first multi-stage hydraulic cylinder 4 and the second multi-stage hydraulic cylinder 15 generate a stroke difference and form a compound stroke superposition. The stroke difference is converted into the deflection angle of the front folding housing 3 relative to the rear folding housing 10, thereby achieving precise folding steering. At the same time, since the oil supply module synchronously adjusts the pressure oil volume inside the first multi-stage hydraulic cylinder 4 and the second multi-stage hydraulic cylinder 15, the device can synchronously drive the front folding housing 3 to rotate relative to the rear folding housing 10 through asymmetrical driving force, thereby avoiding tire slippage and traction loss during vehicle operation.

[0056] Please refer to it again. Figure 1 A limit block 18 is provided on the outer side of the front folding housing 3, and a brake block 19 is provided on the outer side of the twisting housing 1, and the limit block 18 and the brake block 19 are compatible.

[0057] In this embodiment, the limiting block 18 and the braking block 19 can provide torsional overtravel redundancy protection during the relative rotation of the twisted waist housing 1 and the front folding waist housing 3, thereby further improving the safety performance of the device.

[0058] Please refer to it again. Figure 3 A first step bushing 2 and a second step bushing 5 are assembled between the twisted waist housing 1 and the front folding waist housing 3. The first step bushing 2 and the second step bushing 5 are located at the two ends inside the front folding waist housing 3, respectively. An annular groove is provided on the outer side of the twisted waist housing 1 near the rear folding waist housing 10. A limiting gasket 6 is sleeved inside the annular groove, and the limiting gasket 6 and the second step bushing 5 are compatible.

[0059] In this embodiment, the limiting gasket 6 can limit the front folding housing 3 and prevent the front folding housing 3 from detaching from the outside of the twisted housing 1.

[0060] The working principle of this utility model is as follows:

[0061] The driver adjusts and controls the direction of the folding tractor via the steering wheel 11, and obtains the rotation angle of the steering wheel 11 via the steering gear 12. The proportional valve controller adjusts the flow ratio of the first and second oil circuits according to the rotation angle of the steering wheel 11, so that the oil supply module delivers or recovers pressurized oil to the first multi-stage hydraulic cylinder 4 and the second multi-stage hydraulic cylinder 15 according to the rotation angle. This causes a stroke difference between the first multi-stage hydraulic cylinder 4 and the second multi-stage hydraulic cylinder 15, forming a compound stroke superposition. The stroke difference is converted into the deflection angle of the front folding housing 3 relative to the rear folding housing 10, thereby achieving precise folding steering. When the vehicle is driving on rough roads or turning, causing the wheels to lift off the ground, the gravitational torque reacts with the ground. The interaction of forces drives the torsional housing 1 to rotate relative to the front folding housing 3. After the torsional housing 1 rotates, it causes the first torsion spring 16 or the second torsion spring 17 to contract and absorb the torsional load of the vehicle body. When the torsional housing 1 rotates relative to the front folding housing 3 and the torsional angle reaches the upper or lower threshold, it triggers a sudden change in the stiffness of the first torsion spring 16 or the second torsion spring 17. The first torsion spring 16 or the second torsion spring 17 forms a limit on the torsional housing 1 and the front folding housing 3, locking the maximum torsional angle of the torsional housing 1 relative to the front folding housing 3. When the vehicle resumes stable driving, the first torsion spring 16 or the second torsion spring 17 in the contracted state releases elastic potential energy to drive the torsional housing 1 to reset, so that the torsional joint returns to its initial state.

[0062] The above are merely preferred embodiments of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the field.

Claims

1. A tractor with a twisting and bending double-joint steering device, characterized in that: include: Twisting joint assembly, bending joint assembly, torsion spring assembly, hydraulic drive assembly, and coordinated control assembly; The twisting joint assembly includes a twisting shell (1) and a front folding shell (3) arranged coaxially. The twisting shell (1) and the front folding shell (3) are nested together in a sleeve manner, and the twisting shell (1) and the front folding shell (3) can rotate relative to each other around the central axis of the twisting shell (1). The folding joint assembly includes a T-shaped pin (8) and a rear folding housing (10). The T-shaped pin (8) is rotatably connected to the end of the front folding housing (3) away from the twisting housing (1). The rear folding housing (10) is rotatably connected to the outside of the T-shaped pin (8), and the rear folding housing (10) can rotate around the central axis of the T-shaped pin (8). The hydraulic drive assembly is mounted between the front folding housing (3) and the rear folding housing (10), and the hydraulic drive assembly is configured to drive relative rotation between the folding joint assembly and the twisting joint assembly; The torsion spring assembly is assembled between the torsion waist housing (1) and the front folding waist housing (3). The torsion spring assembly is configured to autonomously perform compression / reset actions according to changes in ground energy, and trigger a sudden change in stiffness to achieve limit when the torsion angle reaches a threshold. The collaborative control component is connected to the hydraulic drive component, and the collaborative control component is configured to drive the hydraulic drive component to operate. During the turning process of the tractor, the hydraulic drive assembly can apply an asymmetrical driving force to the torsion joint assembly, and the torsion spring assembly can absorb the torsional load of the vehicle body.

2. The tractor twisting and bending double-joint steering device according to claim 1, characterized in that: The hydraulic drive assembly includes a first multi-stage hydraulic cylinder (4) and a second multi-stage hydraulic cylinder (15). The first multi-stage hydraulic cylinder (4) and the second multi-stage hydraulic cylinder (15) are rotatably connected to the outside of the rear folding housing (10). The output ends of the front folding housing (3) and the first multi-stage hydraulic cylinder (4) and the output ends of the front folding housing (3) and the second multi-stage hydraulic cylinder (15) are rotatably connected.

3. A tractor twisting and bending double-joint steering device according to claim 1, characterized in that: The torsion spring assembly includes a first torsion spring (16) and a second torsion spring (17). The first torsion spring (16) and the second torsion spring (17) are both assembled between the torsion waist shell (1) and the front folding waist shell (3) and are located outside the front folding waist shell (3). In the initial state, the first torsion spring (16) and the second torsion spring (17) are both in a free state. The first torsion spring (16) is configured to trigger a stiffness mutation to limit the torsion waist shell (1) and the front folding waist shell (3) when the torsion angle reaches the upper limit threshold and the torsion waist shell (1) rotates in the forward direction relative to the front folding waist shell (3), and the second torsion spring (17) is in a free state. The second torsion spring (17) is configured to trigger a stiffness mutation to limit the torsion waist shell (1) and the front folding waist shell (3) when the torsion waist shell (1) rotates in the reverse direction relative to the front folding waist shell (3) and the torsion angle reaches the lower limit threshold, and the first torsion spring (16) is in a free state.

4. A tractor twisting and bending double-joint steering device according to claim 3, characterized in that: The inner wall of the front folding housing (3) is provided with multiple positioning protrusions, and the inside of the positioning protrusions is provided with slots. The ends of the first torsion spring (16) and the second torsion spring (17) that are far apart from each other are respectively adapted to the multiple slots.

5. A tractor twisting and bending double-joint steering device according to claim 2, characterized in that: The collaborative control component includes a steering wheel (11) and a steering gear (12). The input ends of the steering wheel (11) and the steering gear (12) are fixedly connected. A proportional valve controller is integrated on the outside of the steering gear (12). The proportional valve controller has a first output end and a second output end. One second multi-stage hydraulic cylinder (15) is connected to the first output end through a first oil pipe (13). Another second multi-stage hydraulic cylinder (15) is connected to the second output end through a second oil pipe (14). The first output end, the first oil pipe (13), and the second multi-stage hydraulic cylinder (15) connected to the first oil pipe (13) constitute a first oil circuit. The second output end, the second oil pipe (14), and the second multi-stage hydraulic cylinder (15) connected to the second oil pipe (14) constitute a second oil circuit. The proportional valve controller is configured to adjust the flow ratio of the first oil circuit and the second oil circuit after the steering gear (12) obtains the rotation angle of the steering wheel (11).

6. A tractor twisting and bending double-joint steering device according to claim 1, characterized in that: A limiting block (18) is provided on the outer side of the front folding housing (3), and a braking block (19) is provided on the outer side of the twisting housing (1), and the limiting block (18) and the braking block (19) are compatible.

7. A tractor twisting and bending double-joint steering device according to claim 1, characterized in that: A first step bushing (2) and a second step bushing (5) are assembled between the twisted waist shell (1) and the front folding waist shell (3), and the first step bushing (2) and the second step bushing (5) are located at both ends inside the front folding waist shell (3).

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