Device and control method for preventing steering wheel from deflecting when truck is traveling straight

Abstract

The present invention relates to the technical field of truck steering, and discloses a device for preventing the steering wheel of a truck from deflecting when the truck is traveling straight. The device comprises a steering arm arranged on a steering machine, the lower end of the steering arm is connected to a worm screw by a connecting base, the input end of the worm screw is connected to a servo motor, the other end is connected to a straight pull rod by a front ball pin, the other end of the straight pull rod is connected to a vehicle axle by a rear ball pin, a displacement sensor is installed on the side wing surface of the frame directly above the axle, an angle sensor is installed on the displacement sensor, the measuring end of the displacement sensor is fixed to the upper wing surface of the axle, and the servo motor, the angle sensor and the displacement sensor are all connected to an ECU control unit. The present invention also discloses a control method for the device for preventing the steering wheel of a truck from deflecting when the truck is traveling straight. The device for preventing the steering wheel of a truck from deflecting when the truck is traveling straight and the control method thereof are automatically adjusted according to the suspension compression amount to compensate for the interference effect on the steering system, and have high reliability and safety.

Description

Technical Field

[0001] The invention relates to the technical field of truck steering, and in particular to a device for preventing a steering wheel from deflecting when the truck is traveling straight, and a control method thereof. Background Art

[0002] When a truck is empty and driving straight, the steering wheel is in a normal centered position. However, when it is fully loaded with cargo, the steering wheel will automatically deflect and tilt. This problem is a common phenomenon in trucks.

[0003] According to actual measurements, the maximum steering wheel deflection angle of many models when fully loaded even reaches more than 20 degrees. On the one hand, the steering wheel deflection easily causes the steering wheel to block the driver's view of the instrument panel during driving, affecting driving comfort and safety; on the other hand, when the car passes through bumpy roads, due to the steering wheel deflection, the driver's hand holding the steering wheel position is unreasonable, resulting in the phenomenon of the steering wheel hitting the hand when the steering wheel swings, affecting driving safety.

[0004] There are two main factors that cause steering wheel deflection:

[0005] 1) When the vehicle is loaded with cargo from empty, the front axle load gradually increases, the front suspension leaf spring is compressed downward, and the steering gear fixed on the frame drives the ball pin connecting the drop arm and the front end of the straight tie rod to move downward, causing the angle of the straight tie rod to change, causing the X-direction distance between the steering drop arm and the steering knuckle to change, thereby pushing (pulling) the steering drop arm to swing forward and backward;

[0006] 2) When the leaf spring of the front suspension is compressed, the arc height of the leaf spring becomes smaller or even flattened. Since the front end of the leaf spring is fixed to the frame by a leaf spring pin, and the rear end is connected by a lifting ear and can swing forward and backward, when the arc height of the leaf spring becomes smaller, the center point of the leaf spring will swing upward around the center point of the front winding ear, pushing the axle away from the steering gear, increasing the X-direction distance between the steering drop arm and the steering knuckle, thereby driving the drop arm to swing backward.

[0007] Due to the limitation of the spatial arrangement of the components of the steering transmission system, the deflection caused by the swing of the straight tie rod and the deflection caused by the compression and upward swing of the leaf spring are inconsistent. The difference between the two movements is the motion interference between the steering transmission system and the front suspension system. In the process of the car from empty to full of cargo, if the interference is too large, it will inevitably cause the steering arm to swing an angle, which will be directly transmitted to the steering wheel, causing the steering wheel to deflect a certain angle. If the deflection angle exceeds the free clearance of the steering transmission mechanism, the steering wheel will deflect. Summary of the invention

[0008] The purpose of the present invention is to address the deficiencies of the above-mentioned technology and to provide a device for preventing the steering wheel from deflecting when a truck is traveling straight and a control method thereof, which automatically adjusts according to the compression amount of the suspension to compensate for the interference effect on the steering system and has high reliability and safety.

[0009] To achieve the above-mentioned purpose, the device for preventing the steering wheel from deflecting when a truck is driving straight ahead, according to the present invention, comprises a steering vertical arm arranged on a steering gear, the lower end of the steering vertical arm is connected to a turbine screw by a connecting base, the input end of the turbine screw is connected to a servo motor, the other end is connected to a straight pull rod by a front ball pin, the other end of the straight pull rod is connected to a vehicle axle by a rear ball pin, a displacement sensor is installed on the side wing surface of the frame directly above the axle, an angle sensor is installed on the displacement sensor, the measuring end of the displacement sensor is fixed to the upper wing surface of the axle in the vertical direction, and the servo motor, the angle sensor and the displacement sensor are all connected to an ECU control unit.

[0010] Preferably, the displacement sensor detects displacement data of the axle.

[0011] Preferably, the angle sensor detects a deflection angle of the displacement sensor.

[0012] Preferably, the ECU control unit receives a brake pedal switch signal as an interrupt signal.

[0013] A control method for a device for preventing steering wheel deflection when a truck is traveling straight ahead. When the vehicle is loaded, a displacement sensor and an angle sensor detect the amount and direction of compression deformation of the axle, convert the result into an electrical signal and transmit it to an ECU control unit. The ECU control unit analyzes and calculates the corresponding compensation instruction, i.e., the length compensation amount of the worm screw that needs to be adjusted, through the received signal, and then controls the rotation of the worm screw through a servo motor to adjust its length.

[0014] Preferably, a brake pedal switch signal is connected to the ECU control unit as an interrupt signal. When the driver steps on the brake pedal, the ECU control unit does not read the signals of the displacement sensor and the angle sensor, and maintains the current state of the steering system.

[0015] Preferably, the initial values ​​of L, H0, and S0 are calibrated in the no-load state, where L is the linear distance between the center points of the front ball pin and the rear ball pin of the straight tie rod in the no-load state and projected on the XZ plane, S0 is the Z-direction height difference between the center points of the front ball pin and the rear ball pin of the straight tie rod in the no-load state, and H0 is the displacement sensor reading in the no-load state, that is, the Z-direction distance from the frame to the upper surface of the axle. When the vehicle is loaded with goods or braked, the displacement sensor degree H1 and the angle sensor degree α are obtained, then the X-direction displacement of the axle relative to the steering gear △S1=H1sinα, and the X-direction displacement of the rear ball pin caused by the change in the straight tie rod angle is The length compensation amount of the worm screw that needs to be adjusted is Among them, a positive △S calculation result means that the worm screw is adjusted backward and the length increases, and a negative △S calculation result means that the length decreases.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. Monitor the suspension status in real time through the displacement and angle sensors on the suspension, and adjust the hard point position of the steering mechanism in time according to the suspension changes, so as to quickly and accurately compensate for the interference of the suspension system on the steering system;

[0018] 2. The connection length between the steering drop arm and the straight tie rod is controlled by the turbine screw, so that the interference effect on the steering system can be compensated by automatic adjustment according to the compression of the suspension;

[0019] 3. The device has a simple structure, small size and convenient layout, and the worm screw has a self-locking feature. After adjusting to the appropriate position, there is no need to add additional locking devices. It can work stably under large loads and has high reliability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The schematic diagram of the structure of the device for preventing the steering wheel from deflecting when the truck is traveling straight is provided in accordance with the present invention;

[0021] Figure 2 A schematic diagram of the structure from another angle;

[0022] Figure 3 Schematic diagram of suspension changes when loading or braking.

[0023] The components in the figure are numbered as follows:

[0024] Steering gear 1, steering drop arm 2, connecting base 3, turbine screw 4, servo motor 5, front ball pin 6, straight tie rod 7, rear ball pin 8, axle 9, displacement sensor 10, angle sensor 11. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1 and Figure 2As shown, a device for preventing the steering wheel of a truck from deflecting when it is driving straight, comprises a steering arm 2 arranged on a steering gear 1, and is characterized in that: the lower end of the steering arm 2 is connected to a turbine screw 4 through a connecting base 3, the input end of the turbine screw 4 is connected to a servo motor 5, the other end is connected to a straight pull rod 7 through a front ball pin 6, the other end of the straight pull rod 7 is connected to a vehicle axle 9 through a rear ball pin 8, a displacement sensor 10 is installed on the side wing surface of the frame directly above the axle 9, an angle sensor 11 is installed on the displacement sensor 10, the measuring end of the displacement sensor 10 is fixed to the upper wing surface of the axle 9 in the vertical direction, and the servo motor 5, the angle sensor 11 and the displacement sensor 10 are all connected to the ECU control unit.

[0027] The displacement sensor 10 detects the displacement data of the axle 9 , and the angle sensor 11 detects the deflection angle of the displacement sensor 10 .

[0028] In addition, for safety reasons, during braking conditions, the device may experience a delayed response or overshoot due to drastic changes in the suspension system's posture, affecting braking stability. The brake pedal switch signal is connected to the ECU control unit as an interrupt signal. When the driver steps on the brake pedal, the ECU control unit does not read the signals of the displacement sensor 10 and the angle sensor 11, and maintains the current state of the steering system.

[0029] When this embodiment is used, after the vehicle is loaded, the displacement sensor 10 and the angle sensor 11 detect the amount and direction of the compressive deformation of the axle 9, convert them into electrical signals and transmit them to the ECU control unit. The ECU control unit analyzes and calculates the corresponding compensation instructions based on the received signals, that is, the length compensation amount of the worm screw 4 that needs to be adjusted, and then controls the rotation of the worm screw 4 through the servo motor 5 to adjust its length.

[0030] The brake pedal switch signal is connected to the ECU control unit as an interrupt signal. When the driver steps on the brake pedal, the ECU control unit does not read the signals of the displacement sensor 10 and the angle sensor 11, and maintains the current state of the steering system.

[0031] Specifically, Figure 3 As shown, the initial values ​​of L, H0, and S0 are calibrated in the no-load state. L is the linear distance between the center points of the front ball pin 6 and the rear ball pin 8 of the straight tie rod 7 in the no-load state and projected on the XZ plane. S0 is the Z-direction height difference between the center points of the front ball pin 6 and the rear ball pin 8 of the straight tie rod 7 in the no-load state. H0 is the reading of the displacement sensor 10 in the no-load state, that is, the Z-direction distance from the frame to the upper surface of the axle 9. When the vehicle is loaded with goods or braked, the degree H1 of the displacement sensor 10 and the degree α of the angle sensor 11 are obtained. Then, the X-direction displacement of the axle 9 relative to the steering gear 1 is △S1=H1sinα, and the X-direction displacement of the rear ball pin 8 caused by the angle change of the straight tie rod 7 is The length compensation amount of the worm screw 4 to be adjusted is Wherein, a positive result of △S calculation indicates that the worm screw 4 is adjusted backward and the length increases, and a negative result indicates that the length decreases.

[0032] The device for preventing the steering wheel from deflecting when the truck is traveling straight and the control method thereof monitor the suspension state in real time through the displacement and angle sensors on the suspension, and timely adjust the hard point position of the steering mechanism according to the suspension change, so as to quickly and accurately compensate for the interference effect of the suspension system on the steering system; the connection length of the steering drop arm 2 and the straight pull rod 7 is controlled through the worm screw 4, so as to realize automatic adjustment according to the compression amount of the suspension to compensate for the interference effect on the steering system; the device has a simple structure, a small size and is easy to arrange, and the worm screw 4 has a self-locking characteristic, and no additional locking device needs to be added after being adjusted to a suitable position, and can work stably under a large load, and has high reliability and safety.

Claims

1. A device for preventing the steering wheel of a truck from deflecting when the truck is traveling straight ahead, comprising a steering drop arm (2) arranged on a steering machine (1), characterized in that: The lower end of the steering drop arm (2) is connected to a turbine screw (4) via a connecting base (3); the input end of the turbine screw (4) is connected to a servo motor (5); the other end is connected to a straight pull rod (7) via a front ball pin (6); the other end of the straight pull rod (7) is connected to a vehicle axle (9) via a rear ball pin (8); a displacement sensor (10) is installed on the side wing surface of the frame directly above the axle (9); an angle sensor (11) is installed on the displacement sensor (10); the measuring end of the displacement sensor (10) is fixed to the upper wing surface of the axle (9) in the vertical direction; the servo motor (5), the angle sensor (11) and the displacement sensor (10) are all connected to an ECU control unit; the displacement sensor (10) detects displacement data of the axle (9); the angle sensor (11) detects the deflection angle of the displacement sensor (10); and the ECU control unit receives a brake pedal switch signal as an interrupt signal; The length compensation amount of the worm screw (4) to be adjusted The calculated result of △S is positive, which means that the worm screw (4) is adjusted backward and the length increases, and negative, which means that the length decreases. In the formula, L is the linear distance of the projection of the center points of the front ball pin (6) and the rear ball pin (8) of the straight tie rod (7) on the XZ plane in the no-load state, S0 is the Z-direction height difference between the center points of the front ball pin (6) and the rear ball pin (8) of the straight tie rod (7) in the no-load state, and H0 is the reading of the displacement sensor (10) in the no-load state, that is, the Z-direction distance from the frame to the upper surface of the axle (9). When the vehicle is loaded with goods or braked, the degree H1 of the displacement sensor (10) and the degree α of the angle sensor (11) are obtained, then the X-direction displacement of the axle (9) relative to the steering gear (1) △S1=H1sinα, and the X-direction displacement of the rear ball pin (8) caused by the angle change of the straight tie rod (7) is 2. A method for controlling the device for preventing the steering wheel from deflecting when the truck is traveling straight as claimed in claim 1, characterized in that: When the vehicle is loaded, the displacement sensor (10) and the angle sensor (11) detect the amount and direction of the compression deformation of the axle (9), convert them into electrical signals and transmit them to the ECU control unit. The ECU control unit analyzes and calculates the corresponding compensation instructions based on the received signals, that is, the length compensation amount that the turbine screw (4) needs to be adjusted, and then controls the rotation of the turbine screw (4) through the servo motor (5) to adjust its length.

3. The control method of the device for preventing the steering wheel from deflecting when the truck is traveling straight as claimed in claim 2, characterized in that: A brake pedal switch signal is connected to the ECU control unit as an interrupt signal. When the driver steps on the brake pedal, the ECU control unit does not read the signals of the displacement sensor (10) and the angle sensor (11), and maintains the current state of the steering system.

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