An auxiliary mechanism for automatically reducing the turning radius

Abstract

This invention relates to the field of steering control in agricultural machinery and automobiles, specifically to an auxiliary mechanism for automatically reducing the steering radius. The mechanism includes a steering detection unit, a braking actuator, a four-wheel drive control unit, and a power operation unit. The steering detection unit is mounted on the front axle to detect the steering limit position. The braking actuator is mounted on the rear axle to perform braking actions. The four-wheel drive control unit controls the engagement and disengagement of the four-wheel drive system. The power operation unit provides power and steering. The steering detection unit and the braking actuator are connected via wiring harnesses. The braking actuator is connected to the four-wheel drive control system wiring harness, and the power operation unit is connected to the four-wheel drive control system wiring harness. This invention solves the drawbacks of current methods that rely on front-wheel steering or differential steering.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery and automobile steering control, and specifically to an auxiliary mechanism for automatically reducing the steering radius. Background Technology

[0002] As a type of power machinery, tractors must be adaptable to various plots of land and various working environments. When working on small plots of land, the tractor's turning flexibility directly affects the working efficiency. Therefore, the minimum turning radius is an important parameter for measuring the performance of a tractor.

[0003] Current tractor steering systems primarily rely on two methods: front-wheel steering or differential steering. Front-wheel steering has a simple structure, but its turning radius is large when working in small plots, often requiring multiple forward and backward maneuvers to complete a turn. This not only reduces work efficiency but also easily causes soil compaction and crop damage. Differential steering achieves steering through the difference in speed between the two drive wheels. While it can reduce the turning radius, it suffers from severe tire wear, high power loss, and poor low-speed steering stability. In addition, some high-end tractors use articulated steering, which offers better flexibility, but its complex structure, high manufacturing cost, and high driver skill requirements make it difficult to widely apply to ordinary agricultural tractors.

[0004] In summary, an auxiliary mechanism for automatically reducing the turning radius is proposed to solve the problems mentioned in the background art. Summary of the Invention

[0005] The purpose of this invention is to provide an auxiliary mechanism that automatically reduces the turning radius, enabling the switching from four-wheel drive to two-wheel drive and unilateral braking during turning, thereby reducing the overall turning radius of the machine.

[0006] An auxiliary mechanism for automatically reducing the turning radius includes a steering detection unit, a braking actuator, a four-wheel drive control unit, and a power operation unit. The steering detection unit is mounted on the front axle and detects the steering limit position. The braking actuator is mounted on the rear axle and performs braking actions. The four-wheel drive control unit controls the engagement and disengagement of the four-wheel drive system. The power operation unit provides power and steering. The steering detection unit and the braking actuator are connected by a wiring harness. The braking actuator is connected to the four-wheel drive control system wiring harness, and the power operation unit is connected to the four-wheel drive control system wiring harness.

[0007] Further specifying, the steering detection unit includes a left steering arm, a right steering arm, a first power-off switch, and a second power-off switch. The left and right steering arms are both mounted on the front axle. The first and second power-off switches are respectively mounted on the left and right sides of the front axle, and the wiring harnesses of the first and second power-off switches are connected.

[0008] Further specifying, the braking actuator includes a brake rocker arm, a left electric push rod, a right electric push rod, a handbrake switch, and a single-sided brake switch. There are two brake rockers, located on the left and right sides of the rear axle brake, respectively, to brake the left and right rear wheels. The left and right electric push rods are connected to the left and right brake rockers, respectively. The handbrake switch and the single-sided brake switch are both located in the driver's cab. The handbrake switch controls the left and right electric push rods to achieve parking brake operation. The first power-off switch is connected to the wiring harness of the left electric push rod, the second power-off switch is connected to the wiring harness of the right electric push rod, the wiring harnesses of the left and right electric push rods are connected, the handbrake switch is connected to the wiring harnesses of the left and right electric push rods, and the single-sided brake switch is connected to the wiring harnesses of the left electric push rod and the handbrake switch.

[0009] Further specifying, the four-wheel drive control unit includes an electromagnetic switch, an electromagnetic clutch, and a switching switch. The electromagnetic switch is fixedly installed in the cab. The electromagnetic clutch is located on the four-wheel drive transfer case of the rear axle and is connected to the gear of the four-wheel drive transfer case. The four-wheel drive transfer case is engaged and disengaged by energizing and de-energizing. It is engaged when energized and disengaged when de-energized. The electromagnetic switch controls the engagement and disengagement of the electromagnetic clutch by switching the current on and off. The electromagnetic switch is connected to the wiring harness of the second power-off switch, the electromagnetic clutch, and the switching switch. The switching switch is connected to the wiring harness of the left electric push rod and the single-sided brake switch.

[0010] Further specifying, the power operation unit includes a steering cylinder, a battery, and a steering wheel. The battery provides power, the steering wheel adjusts the steering, the steering cylinder provides steering power, the steering cylinder and the battery are installed in the vehicle body, and the battery is connected to the handbrake switch wiring harness.

[0011] Compared with the prior art, the advantages of this invention are as follows:

[0012] 1. When the steering wheel is fully turned, it switches from four-wheel drive to two-wheel drive, reducing the turning radius, eliminating the constraint of the rear axle drive shaft on the steering, reducing steering resistance, and, together with the single-sided braking effect, significantly reducing the actual turning radius of the vehicle.

[0013] 1. When the preset limit steering position is reached, i.e., when the steering is fully turned, the first power-off switch is triggered. This switch sends an electrical signal to the four-wheel drive control unit through the wiring harness. At the same time, the single-side brake switch is activated synchronously, transmitting a braking command to the switching switch. After receiving the signal, the switching switch immediately drives the left electric push rod to generate braking force on the left rear wheel, achieving a single-side braking effect, thereby forcing the vehicle to make small-radius steering with the left rear wheel as the fulcrum.

[0014] 3. This auxiliary mechanism achieves automatic switching between four-wheel drive and two-wheel drive when the steering wheel is fully turned, as well as the coordinated action of single-sided braking, through mechanical and electrical interlock control. No additional operation by the driver is required. It ensures the smoothness and safety of the steering process and effectively shortens the time and space required for the vehicle to turn around. It is especially suitable for working in narrow spaces or in situations requiring frequent turning. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the system structure and connection relationships of the present invention;

[0016] Figure 2 This is a schematic diagram of the right electric push rod and the brake rocker arm in the present invention, shown in direction A.

[0017] The markings in the diagram correspond to: 1-left steering arm, 2-right steering arm, 3-first power cut-off switch, 4-second power cut-off switch, 5-brake rocker arm, 6-left electric push rod, 7-right electric push rod, 8-handbrake switch, 9-single-sided brake switch, 10-electromagnetic switch, 11-electromagnetic clutch, 12-switch switch, 13-steering cylinder, 14-battery, 15-steering wheel. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] Example:

[0020] like Figure 1 and Figure 2 As shown, an auxiliary mechanism for automatically reducing the steering radius includes a steering detection unit, a braking execution unit, a four-wheel drive control unit, and a power operation unit. The steering detection unit includes a left steering arm 1, a right steering arm 2, a first power-off switch 3, and a second power-off switch 4. The left steering arm 1 and the right steering arm 2 are both mounted on the front axle. The first power-off switch 3 and the second power-off switch 4 are respectively mounted on the left and right sides of the front axle. The wiring harnesses of the first power-off switch 3 and the second power-off switch 4 are connected.

[0021] The braking actuator includes a brake rocker arm 5, a left electric push rod 6, a right electric push rod 7, a handbrake switch, and a single-sided brake switch. There are two brake rockers 5, located on the left and right sides of the rear axle brake, respectively, to brake the left and right rear wheels. The left electric push rod 6 and the right brake push rod 7 are connected to the left and right brake rockers 5, respectively. The handbrake switch 8 and the single-sided brake switch 9 are both located in the cab. The handbrake switch 8 controls the left electric push rod 6 and the right electric push rod 7 to achieve parking brake. The first power-off switch 3 is connected to the wiring harness of the left electric push rod 6, the second power-off switch 4 is connected to the wiring harness of the right electric push rod 7, the handbrake switch 8 is connected to the wiring harnesses of the left electric push rod 6 and the right electric push rod 7, and the single-sided brake switch 9 is connected to the wiring harnesses of the left electric push rod 6 and the handbrake switch 8, respectively.

[0022] The four-wheel drive control unit includes an electromagnetic switch 10, an electromagnetic clutch 11, and a switching switch 12. The electromagnetic switch 10 is fixedly installed in the cab. The electromagnetic clutch 11 is located on the four-wheel drive transfer case of the rear axle and is connected to the gear of the four-wheel drive transfer case. The four-wheel drive transfer case is disengaged and engaged by energizing and de-energizing. It is engaged when energized and disengaged when de-energized. The electromagnetic switch 10 is connected to the wiring harness of the second power-off switch 4, the electromagnetic clutch 11, and the switching switch 12. The switching switch 12 is connected to the wiring harness of the left electric push rod 6 and the single-sided brake switch 9.

[0023] The power control system includes a steering cylinder 13, a battery 14, and a steering wheel 15. The battery provides power, the steering wheel 15 adjusts the steering, and the steering cylinder 13 provides steering power. The steering cylinder 13 and the battery 14 are installed in the vehicle body, and the battery 14 is connected to the handbrake switch 8 wiring harness.

[0024] When the tractor is parking, the handbrake switch 8 can be operated to switch the handbrake switch 8 to the brake position. Current is supplied to the left electric push rod 6 and the right electric push rod 7, which pulls the brake rocker arm 5 to brake. After the whole machine is powered off, the electric push rods remain in the position before the power is cut off, thus realizing the parking brake.

[0025] When the tractor is running normally, the single-side brake switch 9 is in the off state, the left electric push rod 6 and the right electric push rod 7 are in the initial position and do not participate in the work, the brake rocker arm 5 is in the free state, and the driver can achieve the braking function by stepping on the brake pedal and pulling the brake rocker arm 5 with the lever.

[0026] When the tractor is working in the field, the single-sided brake switch can be activated to the single-sided braking state. The current flows through the single-sided brake switch 9 to the left electric push rod 6 and the right electric push rod 7, and then to the second power-off switch 4 and the first power-off switch 3. When the driver reaches the end of the field and operates the steering wheel 15 to turn left, the steering cylinder 13 pushes the left steering arm 1 to move, blocking the first power-off switch 3. The first power-off switch 3 forms a circuit, and the left electric push rod 6 starts to work, pulling the left brake rocker arm 5 to brake the left rear wheel, thus achieving a smaller turning radius. When the driver operates the steering wheel 15 to turn right, the steering cylinder 13 pushes the right steering arm 2 to move, blocking the second power-off switch 4. The second power-off switch 4 forms a circuit, and the right electric push rod 7 starts to work, pulling the right brake rocker arm 5 to brake the right rear wheel, thereby achieving a smaller turning radius.

[0027] By operating the switch 12, the tractor's four-wheel drive, automatic two-wheel drive, and two-wheel drive functions can be switched respectively. When the switch 12 is in the automatic two-wheel drive position, the current flows through the switch 12 to the electromagnetic clutch 11 and is grounded through the electromagnetic switch 10. The electromagnetic clutch 11 is engaged, and the power reaches the front axle through the electromagnetic clutch 11 and the drive shaft, realizing four-wheel drive. When the driver uses the single-sided braking function and operates the steering wheel 15 to turn left or right, the left steering arm 1 or the right steering arm 2 pushes the power-off switch to turn on. The current reaches the electromagnet in the electromagnetic switch 10, and the magnetic force disconnects the circuit of the electromagnetic clutch 11. The electromagnetic clutch 11 is de-energized and disengaged, switching to rear-wheel drive, thereby further reducing the turning radius.

[0028] During steering, the disengagement timing of the electromagnetic clutch 11 is highly synchronized with the unilateral braking action. When the left steering arm 1 or the right steering arm 2 triggers the corresponding power-off switch, the electromagnet inside the electromagnetic switch 10 responds within milliseconds, cutting off the power supply circuit of the electromagnetic clutch 11 and rapidly interrupting the front axle drive power. This design avoids the rigid constraint of the front axle drive shaft on the steering trajectory in four-wheel drive mode, eliminates tire slippage and transmission shock caused by the speed difference between the front and rear axles, and, in conjunction with the braking force of the unilateral rear wheel, enables the vehicle to complete steering with the brake wheel as the instantaneous rotation center. Theoretically, the steering radius can be reduced to 40% to 60% of the original four-wheel drive state.

[0029] The three operating modes of the switch 12 provide the driver with flexible operating options. In addition to the aforementioned automatic two-wheel drive mode, when the switch 12 is in the forced four-wheel drive position, the electromagnetic clutch 11 remains constantly engaged, and the system disables the automatic switching function, suitable for conditions requiring continuous four-wheel drive traction, such as muddy roads and slopes. When the switch 12 is in the two-wheel drive position, the electromagnetic clutch 11 remains constantly disengaged, and the vehicle travels only in two-wheel drive mode. In this case, the single-sided braking function can still be used independently, meeting general small-radius steering needs. The circuit interlock design of the three modes is achieved through the mechanical limit structure inside the switch 12, effectively preventing control malfunctions caused by mode conflicts.

[0030] As an independent power source for the system, the battery 14's capacity must meet the energy consumption under continuous steering conditions. Actual measurements show that in a typical farmland operation cycle, the duration of a single braking action is approximately three to five seconds, and the switching frequency of the electromagnetic clutch 11 is approximately twenty to forty times per hour. Therefore, the rated capacity of the battery 14 should be no less than forty-five amp-hours, and a voltage monitoring module should be installed to prevent brake failure due to low battery level. The hydraulic pressure supply to the steering cylinder 13 is matched and calibrated with the mechanical stroke of the steering arm to ensure sufficient triggering force at the steering limit position to reliably engage the power-off switch, while avoiding excessive impact that could reduce the switch's lifespan.

[0031] The connection between the brake rocker arm 5 and the electric push rod adopts an adjustable linkage structure, which allows the initial clearance to be adjusted according to the wear of the brake, ensuring the consistency of braking response and the stability of braking force. The arrangement of the handbrake switch 8 and the single-sided brake switch 9 in the cab meets the requirements of ergonomics. The operating handles of the two switches adopt a differentiated design, which makes it easy for the driver to quickly identify them by touch under bumpy conditions, reducing the risk of misoperation.

[0032] The auxiliary mechanism described in this embodiment has good adaptability to existing tractor chassis. The mounting bracket of the steering detection unit can be bolted or welded according to the front axle structure, without the need for large-scale processing of the front axle body. The connection interface between the electric push rod of the braking actuator and the brake rocker arm is compatible with conventional lever braking systems, retaining the emergency braking function of the original brake pedal. The electromagnetic clutch 11 of the four-wheel drive control unit is a standard electromagnetic gear clutch, and its mounting flange matches the output end size of mainstream four-wheel drive transfer cases.

[0033] The above provides a detailed description of an auxiliary mechanism for automatically reducing the turning radius provided by the present invention. The description of the specific embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An auxiliary mechanism for automatically reducing the turning radius, characterized in that: It includes a steering detection unit, a braking actuator, a four-wheel drive control unit, and a power operation unit. The steering detection unit is mounted on the front axle to detect the steering limit position. The braking actuator is mounted on the rear axle to perform braking actions. The four-wheel drive control unit controls the engagement and disengagement of the four-wheel drive system. The power operation unit provides power and steering. The steering detection unit and the braking actuator are connected by a wiring harness. The braking actuator is connected to the four-wheel drive control system wiring harness. The power operation unit is connected to the four-wheel drive control system wiring harness.

2. The auxiliary mechanism for automatically reducing the turning radius according to claim 1, characterized in that: The steering detection unit includes a left steering arm (1), a right steering arm (2), a first power-off switch (3), and a second power-off switch (4). The left steering arm (1) and the right steering arm (2) are both mounted on the front axle. The first power-off switch (3) and the second power-off switch (4) are respectively mounted on the left and right sides of the front axle. The wiring harnesses of the first power-off switch (3) and the second power-off switch (4) are connected.

3. The auxiliary mechanism for automatically reducing the turning radius according to claim 2, characterized in that: The braking actuator includes a brake rocker arm (5), a left electric push rod (6), a right electric push rod (7), a handbrake switch (8), and a single-sided brake switch (9). There are two brake rockers (5), located on the left and right sides of the rear axle brake, respectively, to brake the left and right rear wheels. The left electric push rod (6) and the right electric push rod (7) are connected to the left and right brake rockers (5), respectively. The handbrake switch (8) and the single-sided brake switch (9) are both located in the driver's cab. The left electric push rod (6) and the right electric push rod (7) are controlled to realize the parking brake. The first power-off switch (3) is connected to the wiring harness of the left electric push rod (6). The second power-off switch (4) is connected to the wiring harness of the right electric push rod (7). The left electric push rod (6) and the right electric push rod (7) are connected to the wiring harness. The handbrake switch (8) is connected to the wiring harness of the left electric push rod (6) and the right electric push rod (7). The single-sided brake switch (9) is connected to the wiring harness of the left electric push rod (6) and the handbrake switch (8) respectively.

4. The auxiliary mechanism for automatically reducing the turning radius according to claim 3, characterized in that: The four-wheel drive control unit includes an electromagnetic switch (10), an electromagnetic clutch (11), and a switching switch (12). The electromagnetic switch (10) is fixedly installed in the cab. The electromagnetic clutch (11) is located on the four-wheel drive transfer case of the rear axle and is connected to the gear of the four-wheel drive transfer case. The four-wheel drive transfer case is disengaged and engaged by energizing and de-energizing. The electromagnetic switch (10) controls the engagement and disengagement of the electromagnetic clutch (11) by switching the current on and off. The electromagnetic switch (10) is connected to the wiring harness of the second power-off switch (4), the electromagnetic clutch (11), and the switching switch (12). The switching switch (12) is connected to the wiring harness of the left electric push rod (6) and the single-sided brake switch (9).

5. The auxiliary mechanism for automatically reducing turning radius according to claim 4, characterized in that... The power operation unit includes a steering cylinder (13), a battery (14) and a steering wheel (15). The battery (14) provides power, the steering wheel (15) adjusts the steering, the steering cylinder (13) provides steering power, the steering cylinder (13) and the battery (14) are installed in the vehicle body, and the battery (14) is connected to the handbrake switch (8) wiring harness.

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