Novel axle steering centering system

Abstract

The invention discloses a novel axle steering centering system which comprises a power input unit. A programmable controller or a complex sensor is not needed, control logic is constructed only through the relay, the diode, the microswitch and other basic elements, the structure is simple, and the cost is low; no electronic program dependence exists, the anti-electromagnetic interference capacity is high, the device adapts to the severe working environment of engineering / agricultural vehicles, and professional equipment is not needed for maintenance; flexible switching between normal state automatic centering and manual priority control is achieved through a normally-closed self-reset button, in the normal state, a microswitch triggers automatic centering, in the manual mode, the button directly controls steering, logic conflicts do not exist, and the requirements for automatic convenience and manual controllability are met; four isolation diodes realize one-way guiding of signals and prevent current from flowing backward; the normally-closed contacts of the relays are interlocked, simultaneous action of the double relays is avoided, the circuit and the hydraulic motor are protected, and the system reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle chassis control technology, specifically to a novel axle steering centering system. Background Technology

[0002] The rear-wheel steering system is a key functional component of the chassis system of engineering vehicles (such as loaders and excavators) and agricultural vehicles (such as tractors and combine harvesters). Its automatic return-to-center function directly determines the stability of the vehicle's straight-line driving, the convenience of the driver's operation, and the service life of chassis components such as tires, steering tie rods, and hydraulic cylinders. If the wheels cannot automatically return to center after turning, it will not only increase the burden on the driver to continuously adjust the steering wheel, but also lead to uneven tire wear, fatigue damage to the steering mechanism due to long-term biased force, and even affect the vehicle's driving safety.

[0003] Existing rear-wheel steering automatic return-to-center technologies are mainly divided into two categories: electronic and mechanical. However, both have significant drawbacks that fail to meet the core requirements of "low cost, high reliability, and easy maintenance" for engineering and agricultural vehicles. 1. Electronic automatic centering system A typical structure includes a steering angle sensor (such as a Hall sensor or potentiometer), an electronic control unit (ECU), a hydraulic / electric actuator, and a signal processing circuit. Its working principle is as follows: the sensor detects the wheel steering angle in real time and transmits it to the ECU. The ECU determines the wheel offset state through a preset program and controls the actuator to drive the wheel back to center. However, this type of system has significant limitations: High cost: The development costs of ECU, high-precision sensors and customized programs account for 30%-50% of the total cost of the steering system, making it extremely cost-effective for price-sensitive engineering and agricultural vehicles; Poor reliability: Complex electronic circuits are susceptible to electromagnetic interference during vehicle operation (such as electromagnetic pulses from the engine ignition system and voltage fluctuations when the motor starts), which can lead to sensor signal drift, ECU logic confusion, or even complete system failure. Maintenance difficulties: Troubleshooting requires specialized diagnostic equipment, and program updates require returning the vehicle to the factory or being performed by professional technicians, making it unsuitable for engineering vehicles operating in the field or agricultural vehicles operating in rural areas where maintenance resources are scarce.

[0004] 2. Mechanical automatic centering device The return to center is mainly achieved through a return spring and a mechanical transmission mechanism. For example, a flexible cable connects the steering knuckle and the slider. The slider slides along a linear guide rail and compresses the return spring. When the steering force disappears, the spring force drives the slider to return to its original position, thereby causing the wheel to return to center. However, the drawbacks of mechanical devices are also obvious: Wear and jamming: Mechanical transmission components (such as the connection between the slider and the guide rail, and the connection between the cable and the horn) are prone to wear due to long-term friction. In addition, the intrusion of impurities such as dirt and dust can cause the mechanism to jam and the return-to-center function to fail. Response lag: The inertia of the mechanical structure makes the return-to-center speed slow (usually requiring several seconds or even longer), which cannot meet the timely return-to-center requirement after the vehicle has made a rapid turn; Difficult to adjust: If the wheel centering position is off (e.g., due to spring fatigue causing a decrease in preload), the chassis needs to be disassembled to adjust the spring length or guide rail position, which is cumbersome and the accuracy is difficult to guarantee.

[0005] 3. Lack of mode switching and logic control More importantly, most existing automatic centering devices are single-mode (automatic only or manual only), lacking the flexible switching function of "normal automatic centering + manual priority control": When the vehicle needs to manually adjust the wheel position (such as when turning in a tight space or in an emergency), the automatic return-to-center function may conflict with manual operation (such as when manually steering, the automatic return-to-center mechanism still tries to drive the wheels back to center). Switching to manual mode loses the convenience of automatic centering, failing to balance the needs of "automatic convenience" and "manual control". Summary of the Invention

[0006] To solve the above-mentioned technical problems, a novel axle steering centering system is provided, which solves the problems mentioned in the background section.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A novel axle steering centering system includes: The power input unit is used to connect to the vehicle's power supply and output the device's operating voltage. The mode switching unit includes a normally closed self-resetting mode switching button, which is connected in series in the positive output circuit of the power input unit and is used to switch the device's operating mode to the normal automatic return-to-center power supply branch or the manual switching control power supply branch. The position detection unit includes a first normally open micro switch and a second normally open micro switch. The first micro switch is used to detect the leftward position of the vehicle's rear wheel, and the second micro switch is used to detect the rightward position of the vehicle's rear wheel. The manual operation unit includes a left turn button and a right turn button; The drive unit includes a first relay and a second relay. The normally open contact circuit of the first relay is used to control the hydraulic motor to turn left, and the normally open contact circuit of the second relay is used to control the hydraulic motor to turn right. The signal isolation guiding unit includes a first isolation diode, a second isolation diode, a third isolation diode, and a fourth isolation diode; The electrical interlocking unit is composed of the normally closed contacts of the first relay and the normally closed contacts of the second relay connected in series. In the normal automatic return-to-neutral mode, the normally closed contact of the mode switching button is turned on, and the output of the power input unit is divided into an automatic return-to-neutral power supply branch and a manual control power supply branch.

[0008] Preferably, the positive branch of the automatic return power supply is connected to one end of the first micro switch and one end of the second micro switch, respectively. The other end of the first micro switch is connected to the coil control terminal of the second relay through the first isolation diode, and the other end of the second micro switch is connected to the coil control terminal of the first relay through the second isolation diode.

[0009] Preferably, the positive branch of the manual control power supply is connected to one end of the left turn button and one end of the right turn button respectively; the other end of the left turn button is connected to the coil control terminal of the first relay through a third isolation diode, and the other end of the right turn button is connected to the coil control terminal of the second relay through a fourth isolation diode; the normally closed contact of the first relay is connected in series in the coil power supply circuit of the second relay, and the normally closed contact of the second relay is connected in series in the coil power supply circuit of the first relay.

[0010] Preferably, the normally open contact of the first relay is connected in series in the left-turn power supply circuit of the hydraulic motor, and the normally open contact of the second relay is connected in series in the right-turn power supply circuit of the hydraulic motor.

[0011] Preferably, the position detection unit further includes a position transmission component, which includes a flexible cable, a slider, a linear guide rail, and a return spring; one end of the flexible cable is fixedly connected to the steering knuckle of the vehicle's rear wheel, and the other end is fixedly connected to the slider; the slider is slidably engaged on the linear guide rail, and the sliding trajectory of the slider is consistent with the steering direction of the vehicle's rear wheel.

[0012] Preferably, the linear guide rail is provided with a first micro switch and a second micro switch at both ends, and the two micro switches are located on both sides of the slider sliding track; the reset spring is sleeved on the outside of the slider, with one end abutting the end of the linear guide rail and the other end abutting the slider, for driving the slider to reset to the middle position of the linear guide rail.

[0013] Preferably, the mode switching button is a dual-contact self-reset button, including a set of normally closed contacts and a set of normally open contacts; the normally closed contacts are connected in series in the positive output circuit of the power input unit to control the on / off state of the automatic return-to-neutral power branch and the manual control power branch.

[0014] Preferably, one end of the normally open contact is connected to the positive output terminal of the power input unit, and the other end is connected to the positive branch of the manual control power supply branch, so as to switch the manual control power supply branch to be powered by the normally open contact of the mode switching button when the mode switching button is pressed.

[0015] Preferably, the relay contact connection method of the execution drive unit is as follows: The normally open contact of the first relay: one end is connected to the positive terminal of the hydraulic motor's left-turn power supply, and the other end is connected to the negative terminal of the power input unit; The normally open contact of the second relay: one end is connected to the positive terminal of the right-turn power supply of the hydraulic motor, and the other end is connected to the negative terminal of the power input unit. The coil control terminals of the first and second relays are both connected to the positive branch of the automatic return power supply or the manual control power supply through corresponding isolation diodes.

[0016] Preferably, the power input unit includes a fuse connected in series in the positive input circuit of the power input unit, located upstream of the mode switching button, to limit the device's operating current for overcurrent protection.

[0017] Compared with the prior art, the present invention provides a novel axle steering centering system, which has the following beneficial effects: This invention requires no programmable controller or complex sensors, using only basic components such as relays, diodes, and microswitches to construct control logic. It boasts a simple structure and low cost; it is independent of electronic programs, has strong resistance to electromagnetic interference, and is suitable for harsh operating environments in engineering / agricultural vehicles. Maintenance requires no specialized equipment. A normally closed self-resetting button enables flexible switching between "automatic return to center" and "manual priority control"—in normal mode, the microswitch triggers automatic return to center, while in manual mode, the button directly controls steering, with no logical conflicts, balancing the needs of "automatic convenience" and "manual controllability." Four isolation diodes ensure unidirectional signal guidance, preventing backflow of current; normally closed relay contacts interlock to prevent simultaneous operation of two relays, protecting the circuit and hydraulic motor, and improving system reliability. Position detection uses a "flexible cable + slider + microswitch" structure, without precision electronic components, making it wear-resistant, resistant to dirt / dust intrusion, suitable for outdoor operating environments, and with a lifespan far exceeding that of electronic sensors. This solves the pain points of existing electronic sensors being costly and mechanical sensors being prone to jamming. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the system framework of the present invention; Figure 2 This is a schematic diagram of the control logic in this invention. Detailed Implementation

[0019] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0020] Example 1 Please refer to Figure 1 and Figure 2 As shown, a novel axle steering centering system includes: The power input unit is used to connect to the vehicle's power supply and output the device's operating voltage. The mode switching unit includes a normally closed self-resetting mode switching button. The mode switching button is connected in series in the positive output circuit of the power input unit and is used to switch the device's operating mode to the normal automatic return-to-neutral power supply branch or the manual switching control power supply branch. The position detection unit includes a first normally open micro switch and a second normally open micro switch. The first micro switch is used to detect the leftward position of the vehicle's rear wheel, and the second micro switch is used to detect the rightward position of the vehicle's rear wheel. The manual operation unit includes a left turn button and a right turn button; The drive unit includes a first relay and a second relay. The normally open contact circuit of the first relay is used to control the hydraulic motor to turn left, and the normally open contact circuit of the second relay is used to control the hydraulic motor to turn right. The signal isolation guiding unit includes a first isolation diode, a second isolation diode, a third isolation diode, and a fourth isolation diode; The electrical interlocking unit is composed of the normally closed contacts of the first relay and the normally closed contacts of the second relay connected in series. In the normal automatic return-to-neutral mode, the normally closed contact of the mode switching button is turned on, and the output of the power input unit is divided into an automatic return-to-neutral power supply branch and a manual control power supply branch.

[0021] The positive branch of the automatic return-to-neutral power supply is connected to one end of the first micro switch and one end of the second micro switch, respectively. The other end of the first micro switch is connected to the coil control terminal of the second relay through the first isolation diode, and the other end of the second micro switch is connected to the coil control terminal of the first relay through the second isolation diode.

[0022] The positive branch of the manual control power supply is connected to one end of the left turn button and one end of the right turn button respectively; the other end of the left turn button is connected to the coil control terminal of the first relay through the third isolation diode, and the other end of the right turn button is connected to the coil control terminal of the second relay through the fourth isolation diode; the normally closed contact of the first relay is connected in series in the coil power supply circuit of the second relay, and the normally closed contact of the second relay is connected in series in the coil power supply circuit of the first relay.

[0023] The normally open contact of the first relay is connected in series in the left-turn power supply circuit of the hydraulic motor, and the normally open contact of the second relay is connected in series in the right-turn power supply circuit of the hydraulic motor.

[0024] The position detection unit also includes a position transmission component, which includes a flexible cable, a slider, a linear guide rail, and a return spring. One end of the flexible cable is fixedly connected to the steering knuckle of the vehicle's rear wheel, and the other end is fixedly connected to the slider. The slider slides on the linear guide rail, and the sliding trajectory of the slider is consistent with the steering direction of the vehicle's rear wheel.

[0025] The linear guide rail is equipped with a first micro switch and a second micro switch at both ends, and the two micro switches are located on both sides of the slider's sliding trajectory. The reset spring is sleeved on the outside of the slider, with one end abutting the end of the linear guide rail and the other end abutting the slider, and is used to drive the slider to reset to the middle position of the linear guide rail.

[0026] The mode switching button is a dual-contact self-reset button, including a set of normally closed contacts and a set of normally open contacts; the normally closed contacts are connected in series in the positive output circuit of the power input unit to control the on / off state of the automatic return-to-neutral power branch and the manual control power branch.

[0027] One end of the normally open contact is connected to the positive output terminal of the power input unit, and the other end is connected to the positive branch of the manual control power supply branch. This is used to switch the manual control power supply branch to be powered by the normally open contact of the mode switching button when the mode switching button is pressed.

[0028] The relay contact connection method of the actuator is as follows: The normally open contact of the first relay: one end is connected to the positive terminal of the hydraulic motor's left-turn power supply, and the other end is connected to the negative terminal of the power input unit; The normally open contact of the second relay: one end is connected to the positive terminal of the right-turn power supply of the hydraulic motor, and the other end is connected to the negative terminal of the power input unit. The coil control terminals of both the first and second relays are connected to the positive branch of either the automatic return-to-neutral power supply or the manual control power supply via corresponding isolation diodes.

[0029] The power input unit includes a fuse connected in series in the positive input circuit of the power input unit, located upstream of the mode switching button, to limit the device's operating current for overcurrent protection.

[0030] As will be understood by those skilled in the art, the working logic of this system is as follows: Normal automatic return-to-neutral mode (mode switching button not pressed): the normally closed contact is open, and both the automatic return-to-neutral power supply branch and the manual control power supply branch are energized; When the rear wheel veers to the left, the first micro switch closes, and the current path is: automatic return to center power supply branch → first micro switch → first isolation diode → second relay coil → power supply negative terminal. The second relay is activated, and its normally open contact closes to drive the motor to turn right and return to center. When the rear wheel veers to the right, the second micro switch closes, and the current path is: automatic return to center power supply branch → second micro switch → second isolation diode → first relay coil → power supply negative terminal. The first relay is activated, and its normally open contact closes to drive the motor to rotate left and return to center. Manual steering control mode (press the mode switch button): Normally closed contact opens (automatic return power supply branch is de-energized), normally open contact closes (manual control power supply branch is energized). When the left turn button is pressed, the current path is: manual control power supply branch → left turn button → third isolation diode → first relay coil → power supply negative terminal. The first relay is activated to drive the motor to turn left. When the right turn button is pressed, the current path is: manual control power supply branch → right turn button → fourth isolation diode → second relay coil → power supply negative terminal, the second relay is activated to drive the motor to turn right; When the button is released, the relay coil is de-energized, the contacts reset, and the motor stops.

[0031] In summary, this invention eliminates the need for programmable controllers or complex sensors, constructing control logic solely through basic components such as relays, diodes, and microswitches. This results in a simple structure and low cost. It is independent of electronic programs, exhibits strong resistance to electromagnetic interference, adapts to harsh operating environments in engineering / agricultural vehicles, and requires no specialized equipment for maintenance. A normally closed self-resetting button enables flexible switching between "automatic return to center" and "manual priority control"—in normal mode, the microswitch triggers automatic return to center, while in manual mode, the button directly controls steering, ensuring no logical conflicts and balancing the needs of "automatic convenience" and "manual controllability." Four isolation diodes provide unidirectional signal guidance, preventing backflow. Interlocking of normally closed relay contacts prevents simultaneous operation of two relays, protecting the circuit and hydraulic motor and improving system reliability. Position detection employs a "flexible cable + slider + microswitch" structure, eliminating the need for precision electronic components. This design is wear-resistant, resistant to dirt / dust intrusion, suitable for outdoor operating environments, and boasts a lifespan far exceeding that of electronic sensors. Thus, it solves the pain points of high cost in existing electronic systems and susceptibility to jamming in mechanical systems.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A novel axle steering centering system, characterized in that, include: The power input unit is used to connect to the vehicle's power supply and output the device's operating voltage. The mode switching unit includes a normally closed self-resetting mode switching button, which is connected in series in the positive output circuit of the power input unit and is used to switch the device's operating mode to the normal automatic return-to-center power supply branch or the manual switching control power supply branch. The position detection unit includes a first normally open micro switch and a second normally open micro switch. The first micro switch is used to detect the leftward position of the vehicle's rear wheel, and the second micro switch is used to detect the rightward position of the vehicle's rear wheel. The manual operation unit includes a left turn button and a right turn button; The drive unit includes a first relay and a second relay. The normally open contact circuit of the first relay is used to control the hydraulic motor to turn left, and the normally open contact circuit of the second relay is used to control the hydraulic motor to turn right. The signal isolation guiding unit includes a first isolation diode, a second isolation diode, a third isolation diode, and a fourth isolation diode; The electrical interlocking unit is composed of the normally closed contacts of the first relay and the normally closed contacts of the second relay connected in series. In the normal automatic return-to-neutral mode, the normally closed contact of the mode switching button is turned on, and the output of the power input unit is divided into an automatic return-to-neutral power supply branch and a manual control power supply branch.

2. The novel axle steering centering system according to claim 1, characterized in that, The positive branch of the automatic return-to-center power supply is connected to one end of the first micro switch and one end of the second micro switch, respectively. The other end of the first micro switch is connected to the coil control terminal of the second relay through the first isolation diode, and the other end of the second micro switch is connected to the coil control terminal of the first relay through the second isolation diode.

3. The novel axle steering centering system according to claim 1, characterized in that, The positive branch of the manual control power supply circuit is connected to one end of the left turn button and one end of the right turn button, respectively; the other end of the left turn button is connected to the coil control terminal of the first relay through the third isolation diode, and the other end of the right turn button is connected to the coil control terminal of the second relay through the fourth isolation diode; the normally closed contact of the first relay is connected in series in the line power supply circuit of the second relay, and the normally closed contact of the second relay is connected in series in the coil power supply circuit of the first relay.

4. The novel axle steering centering system according to claim 1, characterized in that, The normally open contact of the first relay is connected in series in the left-turn power supply circuit of the hydraulic motor, and the normally open contact of the second relay is connected in series in the right-turn power supply circuit of the hydraulic motor.

5. A novel axle steering centering system according to claim 1, characterized in that, The position detection unit further includes a position transmission component, which includes a flexible cable, a slider, a linear guide rail, and a return spring; one end of the flexible cable is fixedly connected to the steering knuckle of the vehicle's rear wheel, and the other end is fixedly connected to the slider; the slider is slidably engaged with the linear guide rail, and the sliding trajectory of the slider is consistent with the steering direction of the vehicle's rear wheel.

6. A novel axle steering centering system according to claim 5, characterized in that, The linear guide rail is provided with a first micro switch and a second micro switch at both ends, and the two micro switches are located on both sides of the slider sliding track. The reset spring is sleeved on the outside of the slider, with one end abutting the end of the linear guide rail and the other end abutting the slider, and is used to drive the slider to reset to the middle position of the linear guide rail.

7. A novel axle steering centering system according to claim 1, characterized in that, The mode switching button is a dual-contact self-reset button, including a set of normally closed contacts and a set of normally open contacts; the normally closed contacts are connected in series in the positive output circuit of the power input unit to control the on / off state of the automatic return-to-neutral power branch and the manual control power branch.

8. A novel axle steering centering system according to claim 8, characterized in that, One end of the normally open contact is connected to the positive output terminal of the power input unit, and the other end is connected to the positive branch of the manual control power supply branch. When the mode switching button is pressed, the manual control power supply branch is switched to be powered by the normally open contact of the mode switching button.

9. A novel axle steering centering system according to claim 1, characterized in that, The relay contact connection method of the execution drive unit is as follows: The normally open contact of the first relay: one end is connected to the positive terminal of the hydraulic motor's left-turn power supply, and the other end is connected to the negative terminal of the power input unit; The normally open contact of the second relay: one end is connected to the positive terminal of the right-turn power supply of the hydraulic motor, and the other end is connected to the negative terminal of the power input unit. The coil control terminals of the first and second relays are both connected to the positive branch of the automatic return power supply or the manual control power supply through corresponding isolation diodes.

10. A novel axle steering centering system according to claim 1, characterized in that, The power input unit includes a fuse connected in series in the positive input circuit of the power input unit, located upstream of the mode switching button, to limit the device's operating current for overcurrent protection.

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