Steering mechanism for machine with variable wheel track

Abstract

The invention discloses a steering mechanism for a variable-wheel-track machine, and belongs to the technical field of agricultural machines. The mechanism is formed by connecting a left half frame and a right half frame which are in mirror symmetry through a telescopic cross beam, the left half frame comprises a frame, a hydraulic transmission system and a left front / rear wheel mechanism connected through a damping system, and the right half frame is structurally symmetrical to the frame. The steering system is linked with a steering booster through a steering wheel, and forms a series oil way with the two-way hydraulic cylinders of the left and right half frames through a hydraulic oil tank and an oil pipe. A two-way hydraulic cylinder synchronous driving structure is innovatively adopted, two sets of hydraulic cylinders achieve four-wheel linkage control through a ball head hinged connecting rod mechanism, and front and rear wheels on the same side achieve reverse steering. According to the design, the four-wheel steering angle is precisely regulated and controlled through the hydraulic system, the advantages of being small in steering radius, high in steering synchronization precision, excellent in damping stability and the like are achieved, maintenance and overhaul are facilitated through the modular structure, and the device is particularly suitable for agricultural operation scenes of complex terrains.

Description

Technical Field

[0001] The invention belongs to the field of agricultural machinery, and in particular relates to a steering mechanism for a variable wheelbase machinery. Background Art

[0002] In the field of agricultural machinery, traditional steering mechanisms have significant defects: the mechanical trapezoidal steering mechanism is limited to a maximum steering angle of 45°, and steering in narrow plots requires multiple adjustments. The patent with application number CN202311855760.6 provides a four-wheel synchronization system, and its equal-angle steering mode still makes the turning radius large. In addition, although the existing four-cylinder independent hydraulic system can achieve an error of ±5°, it relies on a high-cost proportional valve, and the oil circuit delay causes the left and right steering angle deviation to become larger. In addition, the central telescopic mechanism needs to match a multi-stage hydraulic cylinder, which increases the failure rate. For variable wheelbase machinery, the steering drive mechanism is centrally arranged in the middle of the equipment, and the steering link needs to be adjusted synchronously when the crossbeam is extended and retracted, resulting in an increase in the number of parts, which makes it difficult to adapt to the needs of rapid adjustment of 40-120cm ridge spacing. Therefore, there is an urgent need for a steering mechanism that has a small turning radius, high synchronization accuracy, and is suitable for rapid wheelbase adjustment to break through the bottleneck of existing technologies. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a steering mechanism for a variable wheelbase machine.

[0004] A steering mechanism for a variable wheelbase machine, comprising a left half frame, a right half frame, a crossbeam, a steering wheel, a steering booster, a hydraulic oil tank, and an oil pipe that are fixedly connected. The structures of the left half frame and the right half frame are mirror-symmetrical. The crossbeam can be extended and retracted. The steering wheel is connected to the steering booster, and the steering booster can control the flow direction of hydraulic oil in the hydraulic oil tank. The left half frame comprises a frame, and a hydraulic transmission system is fixedly installed on the frame. A left front wheel mechanism and a left rear wheel mechanism are movably installed on both sides of the frame through a shock absorbing system. The first hydraulic cylinder and the second hydraulic cylinder respectively included in the left half frame and the right half frame are both bidirectional hydraulic cylinders and have the same structure. The two form a series oil circuit with the hydraulic oil tank. The connecting rods of the hydraulic transmission system are all movably connected through a ball joint. By controlling the hydraulic transmission system, four wheels can be turned synchronously, and the two wheels on the same side rotate in opposite directions. Furthermore, the shock absorbing system includes a shock absorbing spring, the upper end of which is fixedly connected to the frame, the lower end of which is fixedly mounted with a wheel vertical shaft sleeve, a wheel connecting plate is movably mounted on the side of the frame, and the other end of the wheel connecting plate is movably connected to the wheel vertical shaft sleeve; Further, the left front wheel mechanism includes a left front wheel bracket, a left front wheel is rotatably mounted below the left front wheel bracket, a left front wheel vertical shaft is fixedly mounted above the left front wheel bracket, and the left rear wheel mechanism is in a mirror image relationship with the left front wheel mechanism structure, including a left rear wheel, a left rear wheel bracket and a left rear wheel vertical shaft; Furthermore, the left rear wheel shaft is rotatably mounted in the wheel shaft sleeve, the wheel shaft sleeve axially limits the left rear wheel shaft, and the portion of the left rear wheel shaft extending out of the upper portion of the wheel shaft sleeve is fixedly mounted with a left rear steering arm; Further, a first ball joint is provided at one end of the left rear steering arm, a first connecting rod is movably connected to the first ball joint, a connecting rod steering shaft is provided on the vehicle frame, and a second connecting rod is rotatably mounted on the connecting rod steering shaft; Further, a second ball head hinge point and a third ball head hinge point are provided at both ends of the second connecting rod, one end of the second connecting rod is movably connected to the first connecting rod through the third ball head hinge point, and the other end is movably connected to the third connecting rod through the second ball head hinge point; Furthermore, a left front steering arm is fixedly installed on the upper part of the left front wheel vertical shaft, a fourth ball joint is provided at one end of the left front steering arm, and the left front steering arm is movably connected to the fourth connecting rod through the fourth ball joint; Furthermore, the hydraulic oil tank has a first oil tank oil port and a second oil tank oil port, the first hydraulic cylinder includes a hydraulic cylinder barrel, the hydraulic cylinder barrel has oil port 1 and oil port 2, and the second hydraulic cylinder has oil port 3 and oil port 4. The first oil tank oil port is connected to oil port 2, oil port 1 is connected to oil port 4, and oil port 3 is connected to the second oil tank oil port through oil pipes respectively; Furthermore, a hydraulic rod is installed through the hydraulic cylinder, and a piston is provided in the middle of the hydraulic rod, and the piston divides the hydraulic cylinder into two parts: a first hydraulic chamber and a second hydraulic chamber; Furthermore, the two ends of the hydraulic rod extending out of the hydraulic cylinder are respectively provided with a fifth ball head hinge point and a sixth ball head hinge point. One end of the hydraulic rod is movably connected to the third connecting rod through the fifth ball head hinge point, and the other end is movably connected to the fourth connecting rod through the sixth ball head hinge point.

[0005] The present invention can bring the following beneficial effects: 1. The transmission structure of the present invention can make the front and rear wheels turn in opposite directions, so that the mechanism can turn with a very small turning radius, solving the various inconveniences caused by the large turning radius of agricultural machinery; 2. The present invention uses two hydraulic cylinders connected in series to drive four wheels. Compared with agricultural machinery commonly driven by four cylinders on the market, the present invention is easy to maintain, has lower cost, and has better synchronization of four-wheel steering; 3. The hydraulic cylinder of the present invention is used as the steering drive mechanism of the wheel and is arranged on both sides of the frame. Compared with the general agricultural machinery with adjustable left and right wheel tracks, the present invention does not need to install a multi-stage telescopic rod on the steering drive mechanism when adjusting the left and right wheel tracks. It has a simple structure and a low failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 Shown is the overall structural axonometric view of the present invention Figure 2 Shown is an axonometric view of the present invention in a steering state Figure 3 Shown is the axonometric view of the left half of the structure of the present invention Figure 4 Shown is a side view of the left half of the structure of the present invention Figure 5 Shown Figure 4 A partial enlarged structural diagram of part A Figure 6 Shown Figure 4 A partial enlarged structural diagram of part B Figure 7 The cross-sectional view of the hydraulic cylinder is shown. Figure 8 Shown is a schematic diagram of the working principle of the present invention In the figure: 1-left half frame, 2-right half frame, 3-crossbeam, 4-steering wheel, 5-steering booster, 6-hydraulic oil tank, 601-first oil tank oil port, 602-second oil tank oil port, 7-oil pipe, 8-frame, 9-hydraulic transmission system, 901-first connecting rod, 902a-left rear steering arm, 902b-left front steering arm, 903-second connecting rod, 904-third connecting rod, 905-first hydraulic cylinder, 905a-hydraulic rod, 905b-oil port 1, 905c-piston, 905d-hydraulic cylinder barrel, 905e-oil port 2, 905f-first hydraulic chamber, 905g-second hydraulic chamber, 905'-second hydraulic cylinder, 905'a -Oil port three, 905'b-Oil port four, 906-fourth connecting rod, 907-first ball joint, 908-second ball joint, 909-connecting rod steering shaft, 910-third ball joint, 911-fourth ball joint, 912-fifth ball joint, 913-sixth ball joint, 10-shock absorption system, 1001-wheel connecting plate, 1002-shock absorption spring, 1003-wheel vertical shaft sleeve, 11-left front wheel mechanism, 1101-left front wheel, 1102-left front wheel bracket, 1103-left front wheel vertical shaft, 12-left rear wheel mechanism, 1201-left rear wheel, 1202-left rear wheel bracket, 1203-left rear wheel vertical shaft DETAILED DESCRIPTION

[0007] The following will be combined with the drawings in the embodiments of the patent of the present invention to clearly and completely describe the technical solutions in the embodiments of the patent of the present invention. Obviously, the described embodiments are only part of the embodiments of the patent of the present invention, not all of them. Based on the embodiments in the patent of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the patent of the present invention.

[0008] like Figure 1-Figure 3As shown, the present invention is a steering mechanism for a variable wheelbase machine, comprising a fixedly connected left half frame 1, a right half frame 2 and a cross beam 3, the cross beam 3 can be extended and retracted to adjust the distance between the left wheel and the right wheel, and the left half frame 1 and the right half frame 2 are mirror-symmetrical in structure. The present invention also includes a steering wheel 4, a steering booster 5, a hydraulic oil tank 6, and an oil pipe 7. The steering wheel 4, the steering booster 5, and the hydraulic oil tank 6 are installed on the agricultural machinery (as a general mechanism in the industry, in Figure 8 ), the two hydraulic cylinders of the left half frame 1 and the right half frame 2 are connected in series by an oil pipe 7.

[0009] The left half frame 1 comprises a frame 8 on which a hydraulic transmission system 9 is fixedly mounted, and a left front wheel mechanism 11 and a left rear wheel mechanism 12 are movably mounted on both sides of the frame 8 via a shock absorbing system 10 .

[0010] like Figure 4 and Figure 5 As shown, the shock absorbing system 10 includes a wheel connecting plate 1001, a shock absorbing spring 1002, and a wheel vertical shaft sleeve 1003. The upper end of the shock absorbing spring 1002 is fixedly mounted on the frame 8, and the lower end is fixedly connected to the wheel vertical shaft sleeve 1003. One end of the wheel connecting plate 1001 is movably mounted on the side of the frame 8, and the other end is movably connected to the wheel vertical shaft sleeve 1003.

[0011] The left rear wheel mechanism 12 comprises a left rear wheel bracket 1202 , a left rear wheel 1201 is rotatably mounted below the left rear wheel bracket 1202 , and a left rear wheel vertical shaft 1203 is fixedly mounted above the left rear wheel bracket 1202 .

[0012] The left rear wheel vertical shaft 1203 is installed in the wheel vertical shaft sleeve 1003, and the wheel vertical shaft sleeve 1003 axially limits the left rear wheel vertical shaft 1203, and the left rear wheel vertical shaft 1203 can rotate in the wheel vertical shaft sleeve 1003. The part of the left rear wheel vertical shaft 1203 extending out of the wheel vertical shaft sleeve 1003 is fixedly installed with the left rear steering arm 902a, and the steering of the left rear wheel 1201 can be controlled by controlling the rotation of the left rear steering arm 902a.

[0013] The left rear steering arm 902a is movably connected to one end of the first connecting rod 901 through the first ball joint 907, and the second connecting rod 903 is rotatably mounted on the frame 8 through the connecting rod steering shaft 909. One end of the second connecting rod 903 is movably connected to the first connecting rod 901 through the third ball joint 910, and the other end is movably connected to the third connecting rod 904 through the second ball joint 908.

[0014] like Figure 6As shown, the fourth connecting rod 906 is movably connected to the left rear steering arm 902a via the fourth ball joint 911, and the left rear steering arm 902a is fixedly connected to the left rear wheel vertical shaft 1203. By controlling the rotation of the left rear steering arm 902a, the steering of the left rear wheel 1201 can be controlled.

[0015] like Figure 7 As shown, the first hydraulic cylinder 905 includes a hydraulic cylinder barrel 905d, and the hydraulic cylinder barrel 905d has an oil port 1 905b and an oil port 2 905e; a hydraulic rod 905a is installed through the hydraulic cylinder barrel 905d, and a piston 905c is provided in the middle of the hydraulic rod 905a, and the piston 905c divides the hydraulic cylinder barrel 905d into two parts, a first hydraulic chamber 905f and a second hydraulic chamber 905g; one end of the hydraulic rod 905a extending out of the hydraulic cylinder barrel 905d is movably connected to the third connecting rod 904 through the fifth ball joint 912, and the other end is movably connected to the fourth connecting rod 906 through the sixth ball joint 913. The right half frame 2 is provided with a second hydraulic cylinder 905' with the same structure as the first hydraulic cylinder 905.

[0016] like Figure 8 As shown, the hydraulic oil tank 6 has a first oil tank oil port 601 and a second oil tank oil port 602, the first hydraulic cylinder 905 includes a hydraulic cylinder barrel 905d, the hydraulic cylinder barrel 905d has an oil port 1 905b and an oil port 2 905e, and the second hydraulic cylinder 905' has an oil port 3 905'a and an oil port 4 905'b. The first oil tank oil port 601 is connected to the oil port 2 905e, the oil port 1 905b is connected to the oil port 4 905'b, and the oil port 3 905'a is connected to the second oil tank oil port 602 through the oil pipe 7.

[0017] like Figure 8 As shown (the reversing valve, hydraulic locking device and pressure compensation device are common devices in the hydraulic industry and are not shown in the figure), when turning, a steering mechanism for a variable wheelbase machine of the present invention rotates the steering wheel 4, the steering wheel 4 controls the steering booster 5, the steering booster 5 presses the hydraulic oil in the hydraulic oil tank 6 out from the first tank oil port 601, and enters the second hydraulic chamber 905g through the oil pipe 7 and the oil port 2 905e, the hydraulic oil pushes the piston 905c, the piston 905c and the hydraulic rod 905a pull the fourth connecting rod 906, the fourth connecting rod 906 pulls the left front steering arm 902b to rotate, so that the left front wheel 1101 rotates clockwise around the left front wheel vertical shaft 1103.

[0018] At the same time, the piston 905c pushes the third connecting rod 904, the third connecting rod 904 pushes the second connecting rod 903 to rotate around the connecting rod steering shaft 909, the second connecting rod 903 pulls the first connecting rod 901, and then pulls the left rear steering arm 902a to rotate, so that the left rear wheel 1201 rotates counterclockwise around the left rear wheel vertical shaft 1203.

[0019] The piston 905c squeezes the hydraulic oil in the first hydraulic chamber 905f, and the hydraulic oil flows out from the oil port 1 905b, enters the second hydraulic cylinder 905' through the oil pipe 7 from the oil port 4 905'b, and flows out from the oil port 3 905'a, and flows back to the hydraulic oil tank 6 from the second oil tank oil port 602 through the oil pipe 7, so that the wheels of the right half frame 2 are turned in the symmetrical direction with the wheels of the left half frame 1. Since the pressure in the hydraulic circuit is equal everywhere, the four wheels can realize synchronous turning. The state of the wheels after turning is as follows: Figure 2 shown.

[0020] If the wheels need to be reset, the steering wheel 4 is reset. The steering wheel 4 controls the steering booster 5. The steering booster 5 presses the hydraulic oil out of the second oil tank oil port 602. The reverse flow of the hydraulic oil can realize the reverse action of the first hydraulic cylinder 905 and the second hydraulic cylinder 905', thereby realizing the reset of the four wheels.

[0021] Through the above operations, the mechanism can turn with an extremely small turning radius.

[0022] When large agricultural machinery changes the wheelbase to adapt to the ridge width of different crops, since the steering drive mechanism of the present invention, that is, the cylinders are arranged on both sides of the mechanism and connected in series through flexible hydraulic oil pipes, compared with the steering drive mechanism being arranged in the middle of the mechanism, the structure of the present invention is simpler and easier to maintain.

[0023] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A steering mechanism for a variable wheelbase machine, comprising a left half frame (1), a right half frame (2), a crossbeam (3), a steering wheel (4), a steering booster (5), a hydraulic oil tank (6), and an oil pipe (7) which are fixedly connected. The structures of the left half frame (1) and the right half frame (2) are mirror-symmetrical. The crossbeam (3) can be extended and retracted. The steering wheel (4) is connected to the steering booster (5). The steering booster (5) can control the flow direction of hydraulic oil in the hydraulic oil tank (6). The left half frame (1) comprises a frame (8). A hydraulic transmission system (9) is fixedly mounted on the frame (8). A left front wheel mechanism (11) and a left rear wheel mechanism (12) are movably mounted on both sides of the frame (8) through a shock absorbing system (10). The invention is characterized in that: The first hydraulic cylinder (905) and the second hydraulic cylinder (905') respectively included in the left half frame (1) and the right half frame (2) are both bidirectional hydraulic cylinders with the same structure. The two and the hydraulic oil tank (6) form a series oil circuit. The connecting rods of the hydraulic transmission system (9) are movably connected through the ball joint point. By controlling the hydraulic transmission system (9), the four wheels can be turned synchronously, and the two wheels on the same side rotate in opposite directions.

2. A steering mechanism for a variable wheelbase machine according to claim 1, characterized in that: The shock absorbing system (10) comprises a shock absorbing spring (1002), the upper end of the shock absorbing spring (1002) being fixedly connected to the vehicle frame (8), the lower end of the shock absorbing spring (1002) being fixedly mounted with a wheel vertical shaft sleeve (1003), a wheel connecting plate (1001) being movably mounted on the side of the vehicle frame (8), and the other end of the wheel connecting plate (1001) being movably connected to the wheel vertical shaft sleeve (1003).

3. A steering mechanism for a variable wheelbase machine according to claim 2, characterized in that: The left front wheel mechanism (11) comprises a left front wheel bracket (1102), a left front wheel (1101) is rotatably mounted below the left front wheel bracket (1102), a left front wheel vertical shaft (1103) is fixedly mounted above the left front wheel bracket (1102), and the left rear wheel mechanism (12) is in a mirror image relationship with the left front wheel mechanism (11) in structure, comprising a left rear wheel (1201), a left rear wheel bracket (1202) and a left rear wheel vertical shaft (1203).

4. A steering mechanism for a variable wheelbase machine according to claim 3, characterized in that: The left rear wheel vertical shaft (1203) is rotatably mounted in the wheel vertical shaft sleeve (1003), the wheel vertical shaft sleeve (1003) axially limits the left rear wheel vertical shaft (1203), and the portion of the left rear wheel vertical shaft (1203) extending out of the upper portion of the wheel vertical shaft sleeve (1003) is fixedly mounted with a left rear steering arm (902a).

5. A steering mechanism for a variable wheelbase machine according to claim 4, characterized in that: A first ball joint point (907) is provided at one end of the left rear steering arm (902a), the first ball joint point (907) is movably connected to a first connecting rod (901), a connecting rod steering shaft (909) is provided on the vehicle frame (8), and a second connecting rod (903) is rotatably mounted on the connecting rod steering shaft (909).

6. A steering mechanism for a variable wheelbase machine according to claim 5, characterized in that: A second ball head hinge point (908) and a third ball head hinge point (910) are provided at both ends of the second connecting rod (903); one end of the second connecting rod (903) is movably connected to the first connecting rod (901) via the third ball head hinge point (910), and the other end is movably connected to the third connecting rod (904) via the second ball head hinge point (908).

7. A steering mechanism for a variable wheelbase machine according to claim 6, characterized in that: A left front steering arm (902b) is fixedly mounted on the upper portion of the left front wheel vertical shaft (1103); a fourth ball joint point (911) is provided at one end of the left front steering arm (902b); and the left front steering arm (902b) is movably connected to a fourth connecting rod (906) via the fourth ball joint point (911).

8. A steering mechanism for a variable wheelbase machine according to claim 7, characterized in that: The hydraulic oil tank (6) has a first oil tank oil port (601) and a second oil tank oil port (602); the first hydraulic cylinder (905) includes a hydraulic cylinder barrel (905d); the hydraulic cylinder barrel (905d) has an oil port 1 (905b) and an oil port 2 (905e); the second hydraulic cylinder (905') has an oil port 3 (905'a) and an oil port 4 (905'b); the first oil tank oil port (601) and the oil port 2 (905e); the oil port 1 (905b) and the oil port 4 (905'b); and the oil port 3 (905'a) and the second oil tank oil port (602) are respectively connected through oil pipes (7).

9. A steering mechanism for a variable wheelbase machine according to claim 8, characterized in that: A hydraulic rod (905a) is installed through the hydraulic cylinder (905d), and a piston (905c) is provided in the middle of the hydraulic rod (905a). The piston (905c) divides the hydraulic cylinder (905d) into two parts: a first hydraulic chamber (905f) and a second hydraulic chamber (905g).

10. A steering mechanism for a variable wheelbase machine according to claim 9, characterized in that: A fifth ball head hinge point (912) and a sixth ball head hinge point (913) are respectively provided at both ends of the hydraulic rod (905a) extending out of the hydraulic cylinder (905d); one end of the hydraulic rod (905a) is movably connected to the third connecting rod (904) via the fifth ball head hinge point (912), and the other end is movably connected to the fourth connecting rod (906) via the sixth ball head hinge point (913).

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