Variable height knuckle arm and control method thereof

Abstract

The present invention relates to the technical field of truck steering, and discloses a variable height steering knuckle arm, comprising a steering vertical arm arranged on a steering machine, connected to a straight tie rod through a front ball pin, the other end of the straight tie rod is connected to a rear ball pin, the rear ball pin is installed on the steering knuckle arm through a ball pin height adjustment device, the steering knuckle arm is installed on the steering knuckle, the steering knuckle is installed on the axle, a displacement & angle sensor is installed on the side wing surface of the frame directly above the axle, the measuring end of the displacement & angle sensor is fixed to the upper wing surface of the axle, and the ball pin height adjustment device and the displacement & angle sensor are connected to an ECU control unit. The present invention also discloses a control method for a variable height steering knuckle arm. The variable height steering knuckle arm and the control method thereof of the present invention control the ball pin height of the steering knuckle arm connected to the straight tie rod through a screw rod or a hydraulic cylinder device, so that the straight tie rod angle is automatically adjusted according to the suspension compression to compensate for the interference effect on the steering system.

Description

Technical Field

[0001] The invention relates to the technical field of truck steering, and in particular to a variable-height steering knuckle arm and a control method thereof. Background Art

[0002] The automobile steering system is an important system related to vehicle driving safety, and excellent steering system performance is an important guarantee for vehicle safe driving. The steering knuckle and straight tie rod are important components in the steering system. Their function is to convert the torsional motion around the Y axis output by the steering gear into the steering motion of the wheel around the kingpin. However, during the braking operation and the increase of vehicle loading mass, the front suspension of the vehicle will produce a certain compression. This compression process will interfere with the steering transmission system, and ultimately cause deviation during braking or steering wheel tilt when driving straight. This steering suspension interference phenomenon seriously affects driving safety and vehicle driving comfort.

[0003] There are two main factors that affect the interference of suspension on the steering system:

[0004] 1) When the suspension is compressed, the steering gear drives the ball pin connecting the steering drop arm and the front end of the straight tie rod to sink, 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 knuckle to rotate around the kingpin and driving the wheel to deflect to the left or right, resulting in deviation;

[0005] 2) When the suspension is compressed, the arc height of the leaf spring will become 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 and movable via a lifting lug, when the arc height of the leaf spring becomes smaller, the suspension length becomes longer, which will push the frame forward and increase the X-direction distance between the steering arm and the steering knuckle, thereby pulling the steering knuckle forward to rotate around the kingpin and driving the wheel to deflect to the left, causing deviation.

[0006] Avoiding steering suspension interference has always been a difficult point in truck development, especially when the suspension compression is large when empty and fully loaded, and it is difficult to balance the interference phenomenon under the two load conditions by optimizing the steering linkage. Summary of the invention

[0007] The purpose of the present invention is to address the deficiencies of the above-mentioned technology and provide a variable height steering knuckle arm and a control method thereof, by controlling the height of the ball pin connecting the steering knuckle arm and the straight tie rod through a screw rod or a hydraulic cylinder device, so that the straight tie rod angle is automatically adjusted according to the suspension compression amount to compensate for the interference effect on the steering system.

[0008] To achieve the above-mentioned purpose, the variable height steering knuckle arm designed in the present invention comprises a steering vertical arm arranged on a steering machine, wherein the steering vertical arm is connected to a straight pull rod through a front ball pin, and the other end of the straight pull rod is connected to a rear ball pin, and the rear ball pin is installed on the steering knuckle arm through a ball pin height adjustment device, and the steering knuckle arm is installed on the steering knuckle, and the steering knuckle is installed on the axle, and a displacement & angle sensor is installed on the side wing surface of the frame directly above the axle, and the measuring end of the displacement & angle sensor is fixed to the upper wing surface of the axle in the vertical direction, and the ball pin height adjustment device and the displacement & angle sensor are both connected to the ECU control unit.

[0009] Preferably, the ball pin height adjustment device is a screw lifting device, which is installed on the steering knuckle arm through a base flange and includes a screw, the upper end of which is connected to the rear ball pin, and the screw is connected to a servo motor that drives its movement.

[0010] Preferably, the ball pin height adjustment device is a hydraulic cylinder device, which is installed on the steering knuckle arm through a base flange, and the telescopic shaft of the hydraulic cylinder is connected to the rear ball pin.

[0011] Preferably, the displacement & angle sensor detects the displacement data and the deflection angle of the axle.

[0012] A control method for the variable height steering knuckle arm, when the vehicle is loaded, the displacement & angle sensor detects the compression deformation amount and direction of the vehicle, converts it into an electrical signal and transmits it to the ECU control unit, the ECU control unit analyzes and calculates the corresponding compensation instruction, i.e., the height compensation amount of the ball pin height adjustment device, through the received signal, and then adjusts the height of the rear ball pin.

[0013] Preferably, L and H are 0 , S 0 The initial value is calibrated, 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 the projection on the XZ plane, S 0 H 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. 0 is the displacement sensor reading in the unloaded 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 braking, the displacement reading H of the displacement & angle sensor is obtained. 1 , angle reading α, then the X-direction displacement of the axle relative to the steering gear △S 1 =H 1 sinα, displacement when the pull rod angle changes According to the steering suspension interference compensation principle: △S 1 =△S 2 , then the height compensation of the rear ball pin is

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. The suspension status is monitored in real time through the displacement & angle sensor on the suspension, and the hard point position of the steering mechanism is adjusted 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 and improve driving safety;

[0016] 2. Automatically compensate and adjust the steering knuckle pin height according to the change of the vehicle's front suspension height, so that the height difference between the front and rear ball pins of the steering straight tie rod remains stable, thereby avoiding changes in the vehicle's load mass and steering wheel skew and brake deviation caused by steering suspension interference during emergency braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a variable height steering knuckle arm of the present invention;

[0018] Figure 2 Schematic diagram of suspension changes when loading or braking.

[0019] The components in the figure are numbered as follows:

[0020] Steering gear 1, steering drop arm 2, front ball pin 3, straight tie rod 4, rear ball pin 5, ball pin height adjustment device 6, steering knuckle arm 7, steering knuckle 8, axle 9, displacement & angle sensor 10, screw rod 11, servo motor 12. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, a variable height steering knuckle arm comprises a steering vertical arm 2 arranged on a steering gear 1, the steering vertical arm 2 is connected to a straight tie rod 4 through a front ball pin 3, the other end of the straight tie rod 4 is connected to a rear ball pin 5, the rear ball pin 5 is installed on a steering knuckle arm 7 through a ball pin height adjustment device 6, the steering knuckle arm 7 is installed on a steering knuckle 8, the steering knuckle 8 is installed on an axle 9, a displacement & angle sensor 10 is installed on the side wing surface of the frame directly above the axle 9, the measuring end of the displacement & angle sensor 10 is fixed to the upper wing surface of the axle in the vertical direction, and the ball pin height adjustment device 6 and the displacement & angle sensor 10 are both connected to the ECU control unit.

[0023] In this embodiment, the ball pin height adjustment device 6 is a screw lifting device, which is installed on the steering knuckle arm 7 through a base flange, and includes a screw rod 11, the upper end of which is connected to the rear ball pin 5, and the screw rod 11 is connected to a servo motor 12 that drives its movement.

[0024] In addition, in other embodiments, the ball pin height adjustment device 6 can be a hydraulic cylinder device, which is installed on the steering knuckle arm 7 through a base flange, and the telescopic shaft of the hydraulic cylinder is connected to the rear ball pin 5.

[0025] In this embodiment, the displacement & angle sensor 10 detects the displacement data and the deflection angle of the axle 9 .

[0026] When this embodiment is used, after the vehicle is loaded, the displacement & angle sensor 10 detects the amount and direction of the compressive deformation of the axle 9, converts it into an electrical signal and transmits it to the ECU control unit. The ECU control unit analyzes and calculates the corresponding compensation instruction, that is, the height compensation amount of the ball pin height adjustment device 6, through the received signal, and then adjusts the height of the rear ball pin 5.

[0027] Specifically, Figure 2 As shown, under no-load condition, L and H 0 , S 0 The initial value is calibrated, L is the linear distance between the center points of the front ball pin 3 and the rear ball pin 5 of the straight tie rod 4 in the no-load state and projected on the XZ plane, S 0 H is the height difference in Z direction between the center points of the front ball pin 3 and the rear ball pin 5 of the straight tie rod 4 in the no-load state. 0 is the displacement reading of the displacement & angle sensor 10 in the unloaded 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 displacement reading H of the displacement & angle sensor 10 is obtained. 1 , angle reading α, then the X-direction displacement of the axle 9 relative to the steering gear 1 is △S 1 =H 1 sinα, displacement when the pull rod angle changes△ According to the steering suspension interference compensation principle: △S 1 =△S 2 , then the height compensation of the rear ball pin is

[0028] The variable height steering knuckle arm and control method thereof of the present invention monitor the suspension state in real time through the displacement & angle sensor 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 of the suspension system on the steering system and improve driving safety; the steering knuckle pin shaft height is automatically compensated and adjusted according to the change of the front suspension height of the vehicle, so as to avoid the change of the vehicle load mass and the steering wheel skew and brake deviation caused by the interference of the steering suspension during emergency braking.

Claims

1. A variable height steering knuckle arm, comprising a steering vertical arm (2) arranged on a steering machine (1), wherein the steering vertical arm (2) is connected to a straight tie rod (4) through a front ball pin (3), characterized in that: The other end of the straight tie rod (4) is connected to a rear ball pin (5), the rear ball pin (5) is mounted on a steering knuckle arm (7) through a ball pin height adjustment device (6), the steering knuckle arm (7) is mounted on a steering knuckle (8), the steering knuckle (8) is mounted on an axle (9), a displacement & angle sensor (10) is mounted on a side wing surface of the frame directly above the axle (9), the measuring end of the displacement & angle sensor (10) is fixed to an upper wing surface of the axle in a vertical direction, the ball pin height adjustment device (6) and the displacement & angle sensor (10) are both connected to an ECU control unit, the ball pin height adjustment device (6) is a screw rod lifting device, which is mounted on the steering knuckle arm (7) through a base flange, and comprises a screw rod (11), the upper end of the screw rod (11) is connected to the rear ball pin (5), the screw rod (11) is connected to a servo motor (12) for driving the screw rod to move, and the height compensation amount of the ball pin height adjustment device (6) is Wherein, H0 is the displacement reading of the displacement & angle sensor (10) in the unloaded state, L is the linear distance of the projection of the center points of the front ball pin (3) and the rear ball pin (5) of the straight tie rod (4) in the unloaded state on the XZ plane, S0 is the Z-direction height difference of the center points of the front ball pin (3) and the rear ball pin (5) of the straight tie rod (4) in the unloaded state, H1 is the displacement reading of the displacement & angle sensor (10) when the vehicle is loaded with cargo or braking, and α is the angle reading.

2. The variable height knuckle arm according to claim 1, characterized in that: The ball pin height adjustment device (6) is a hydraulic cylinder device, which is installed on the steering knuckle arm (7) through a base flange, and the telescopic shaft of the hydraulic cylinder is connected to the rear ball pin (5).

3. The variable height knuckle arm according to claim 1, characterized in that: The displacement & angle sensor (10) detects the displacement data and the deflection angle of the axle (9).

4. A control method for a variable height knuckle arm as claimed in claim 1, characterized in that: When the vehicle is loaded, the displacement & angle sensor (10) detects the amount and direction of the compression deformation of the axle (9), converts it into an electrical signal and transmits it to the ECU control unit. The ECU control unit analyzes and calculates the corresponding compensation instruction based on the received signal, that is, the height compensation amount of the ball pin height adjustment device (6), and then adjusts the height of the rear ball pin (5). The initial values ​​of L, H0, and S0 are calibrated in the unloaded state. L is the center point of the front ball pin (3) and the rear ball pin (5) of the straight tie rod (4) in the unloaded state in the XZ plane. S0 is the Z-direction height difference between the center points of the front ball pin (3) and the rear ball pin (5) of the straight tie rod (4) in the unloaded state, H0 is the displacement reading of the displacement & angle sensor (10) in the unloaded 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 displacement reading H1 of the displacement & angle sensor (10) is obtained, and the angle reading α is obtained. Then, the X-direction displacement of the axle (9) relative to the steering gear (1) is △S1=H1sinα, and the displacement when the straight tie rod angle changes is According to the steering suspension interference compensation principle: △S1 = △S2, the height compensation of the rear ball pin is

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