Rack force testing device of steering system

By designing a rack force testing device including a test bench, wheel fixing unit, test unit, drive unit and control unit, the problem of insufficient rack force measurement accuracy in the development of new models is solved, and accurate measurement of rack force of the steering system and support for assisted driving functions are achieved.

CN120063752APending Publication Date: 2025-05-30CHONGQING LANDIAN TECHNOLOGY CO LTD
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Patent Information

Application Number
CN202311633141.2
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2023-11-30
Publication Date
2025-05-30

AI Technical Summary

Technical Problem

In the development of new models, the lack of prototype cars is used for rack force precision testing, resulting in excess or insufficient capacity of the motor selection, resulting in huge waste and risks in development costs and time cycles.

Method used

A rack force testing device for a steering system is provided, including a test bench, a wheel fixing unit, a test unit, a drive unit and a control unit. These components are used to simulate the movement of the rack during vehicle steering and measure parameters such as rack force and rack displacement.

Benefits of technology

Accurate measurement of the rack force of the steering system is achieved, reliable parameter basis is provided, and it provides support for the development of assisted driving functions of the vehicle, reducing development costs and time cycle risks.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention discloses a rack force testing device of a steering system. The rack force testing device comprises a test board; the wheel fixing unit is arranged on the test bench and is used for bearing and fixing a wheel; the testing unit is connected with a hub of the wheel, and the testing unit is used for driving the wheel to steer; the driving unit is connected with the testing unit, and the driving unit is used for providing driving force for steering of the wheels; and the control unit is connected with the wheel fixing unit and the driving unit, and the control unit is used for designing parameters of wheel steering and testing rack force of wheel steering. The wheel fixing unit is used for fixing the tested wheel, the control unit is used for setting the steering parameters of the wheel, the driving unit and the testing unit are used for driving the wheel to rotate to simulate the motion mode of a rack when the vehicle steers, and finally the control unit is used for measuring parameters such as rack force and rack displacement. And a reliable parameter basis is provided for auxiliary driving function development of the vehicle.
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Description

Technical Field

[0001] The present invention relates to the technical field of automotive performance testing devices, and particularly to a rack force testing device for a steering system. Background Art

[0002] At the beginning of the development of a new vehicle model, especially a new chassis platform, there is a lack of prototype vehicles for accurate rack force testing, thus guiding the selection of EPS motors. Currently, empirical formulas or experimental data of benchmark vehicles are widely used to roughly estimate the rack force, but their accuracy is poor, often resulting in an over - capacity or under - capacity of the selected motors. This causes a huge waste and risk in development costs and time cycles.

[0003] In the development of a steering system, the rack force is an important parameter that is difficult to linearly express. Due to the complex multi - body motion mechanism of the suspension steering system and factors such as tire specifications, air pressure, and stiffness differences, there are many variables affecting the rack force, making it difficult to establish an accurate theoretical mathematical model for verification.

[0004] In addition, although sensors can currently be used to accurately measure the axial force of the steering tie rod on the vehicle, generally there are no vehicles that can reach the design state available at the beginning of vehicle model development, and the axial force of the tie rod needs to be further converted into the axial force of the rack. Summary of the Invention

[0005] The purpose of the present invention is to provide a rack force testing device for a steering system to solve the problems in the prior art and be able to accurately measure the rack force of the steering system.

[0006] The present invention provides a rack force testing device for a steering system, including:

[0007] A test bench;

[0008] A wheel fixing unit, which is arranged on the test bench and is used to carry and fix the wheel;

[0009] A test unit, which is connected to the hub of the wheel and is used to drive the wheel to perform a steering motion;

[0010] A driving unit, which is connected to the test unit and is used to provide a driving force for the steering of the wheel;

[0011] A control unit, which is connected to the wheel fixing unit and the driving unit, and is used to design the parameters of the wheel steering and test the rack force of the wheel steering.

[0012] A rack force testing device for a steering system as described above, wherein preferably, the wheel fixing unit includes a lifting mechanism and a locking mechanism, the wheel is arranged on the locking mechanism, the lifting mechanism is fixed on the test bench, the locking mechanism is connected to the lifting mechanism, and the locking mechanism is used to fix the position of the lifting mechanism.

[0013] In the rack force testing device for a steering system as described above, preferably, the lifting mechanism is a scissor-type lifting structure.

[0014] In the rack force testing device for a steering system as described above, preferably, a first sensor is provided between the lifting mechanism and the locking mechanism.

[0015] The rack force testing device for a steering system as described above, wherein preferably, the testing unit comprises a wheel hub steering knuckle, a shock absorbing strut, a suspension swing arm, a steering tie rod, an adapter bracket and a fixed column, wherein:

[0016] The wheel hub steering knuckle comprises a wheel hub mounting plate and a connecting rod, wherein the wheel hub mounting plate is connected to the wheel hub of the wheel, the first end of the connecting rod is connected to the first end of the shock absorbing strut, the second end of the connecting rod is connected to the first end of the suspension swing arm, and the first end of the steering tie rod is connected to the rod body portion between the first end of the connecting rod and the second end of the connecting rod;

[0017] The fixed column is arranged on the test bench, the adapter bracket includes a first bracket and a second bracket, the first bracket and the second bracket are both connected to the fixed pillar, the second end of the shock-absorbing pillar is connected to the first bracket, the second end of the suspension swing arm is connected to the second bracket, and the second end of the steering rod is connected to the drive unit.

[0018] A rack force testing device for a steering system as described above, wherein preferably, the driving unit includes a driving motor, a transmission mechanism and a sliding mechanism, the first end of the sliding mechanism is connected to the second end of the steering rod, and the transmission mechanism is used to transmit the power of the driving motor to the sliding mechanism.

[0019] In the rack force testing device for a steering system as described above, preferably, the transmission mechanism is a ball screw transmission structure.

[0020] In the rack force testing device for a steering system as described above, preferably, a second sensor is provided between the first end of the sliding mechanism and the second end of the steering rod.

[0021] A rack force testing device for a steering system as described above, wherein preferably, a third sensor is provided at the second end of the sliding mechanism.

[0022] A rack force testing device for a steering system as described above, wherein preferably, the control unit includes a test controller and a computer. The test controller is connected to the computer, and the test controller is connected to the driving unit and the wheel fixing unit. The test controller can set the steering parameters of the wheel and test the rack force when the wheel steers.

[0023] Compared with the prior art, the present invention fixes the test wheel by using the wheel fixing unit, sets the parameters of the wheel steering through the control unit, then uses the driving unit and the test unit to drive the wheel to rotate to simulate the movement mode of the rack when the vehicle steers, and finally measures parameters such as the rack force and the rack displacement through the control unit, providing a reliable parameter basis for the development of the vehicle's assisted driving function. Description of the Drawings

[0024] Figure 1 is a schematic structural diagram of the present invention;

[0025] Figure 2 is a schematic working principle diagram of the present invention.

[0026] Description of the Reference Numerals:

[0027] 100 - wheel, 200 - power supply;

[0028] 10 - test bench;

[0029] 20 - wheel fixing unit, 21 - lifting mechanism, 22 - locking mechanism;

[0030] 30 - test unit, 31 - hub steering knuckle, 311 - hub mounting plate, 312 - connecting rod, 32 - shock absorber strut, 33 - suspension swing arm, 34 - steering tie rod, 35 - adapter bracket, 351 - first bracket, 352 - second bracket, 36 - fixed column;

[0031] 40 - driving unit, 41 - driving motor, 42 - transmission mechanism, 43 - sliding mechanism;

[0032] 50 - control unit, 51 - test controller, 52 - computer;

[0033] 60 - first sensor;

[0034] 70 - second sensor;

[0035] 80 - third sensor;

[0036] 90 - wire harness assembly. Detailed implementation mode

[0037] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] Refer to Figure 1 As shown, the present invention provides a rack force test device for a steering system, including a test bench 10, a wheel fixing unit 20, a test unit 30, a driving unit 40, and a control unit 50, where:

[0039] The wheel fixing unit 20, the test unit 30, the driving unit 40, and the control unit 50 are all arranged on the test bench 10, and the test bench 10 provides a support platform for the entire test device.

[0040] The wheel fixing unit 20 is arranged on the test bench 10, and the wheel fixing unit 20 is used to carry and fix the wheel 100. In the embodiments provided in the present application, the wheel fixing unit 20 includes a lifting mechanism 21 and a locking mechanism 22. The wheel 100 is arranged on the locking mechanism 22, and the locking mechanism 22 is an analog road surface, which is convenient for providing contact with the ground for the wheel 100. The lifting mechanism 21 is fixed on the test bench 10, and the lifting mechanism 21 moves from a low position to a high position along the direction of gravity, providing a vertical pressure to the tire of the wheel 100 to simulate the state of the tire on the road surface; the locking mechanism 22 is connected to the lifting mechanism 21, and the locking mechanism 22 is used to fix the position of the lifting mechanism 21. When the lifting mechanism 21 moves upward until the tire receives sufficient vertical pressure, the locking mechanism 22 is used to fix the position of the lifting mechanism 21 to ensure that the tire of the wheel 100 can always receive sufficient vertical pressure.

[0041] In order to monitor in real time whether the vertical pressure received by the tire of the wheel 100 meets the set requirements, a first sensor 60 is arranged between the lifting mechanism 21 and the locking mechanism 22. The first sensor 60 is a pressure sensor, and the pressure sensor can monitor the vertical pressure received by the tire of the wheel 100, which is convenient for adjusting the height of the lifting mechanism 21 according to the numerical requirements of the vertical pressure to meet the test requirements. A wire harness assembly 90 is also arranged on the first sensor 60, and the communication connection between the first sensor 60 and the control unit 50 is realized through the wire harness assembly 90.

[0042] In a feasible implementation mode, the lifting mechanism 21 is a scissor lift structure, and the scissor lift structure has high stability and load-bearing capacity, and can give a stable vertical pressure to the tire of the wheel 100 to ensure the smooth progress of the test.

[0043] The test unit 30 is connected to the hub of the wheel 100, and the test unit 30 is used to drive the wheel 100 to perform a steering movement. In the embodiments provided in the present application, the test unit 30 includes a hub steering knuckle 31, a shock absorber strut 32, a suspension swing arm 33, a steering tie rod 34, a transfer bracket 35, and a fixed column 36, where:

[0044] The hub steering knuckle 31 includes a hub mounting disc 311 and a connecting rod 312. The hub mounting disc 311 is connected to the hub of the wheel 100. The first end of the connecting rod 312 is connected to the first end of the shock absorber strut 32, and the second end of the connecting rod 312 is connected to the first end of the suspension swing arm 33. The first end of the steering tie rod 34 is connected to the rod body portion between the first end and the second end of the connecting rod 312;

[0045] The fixed column 36 is provided on the test bench 10. The transfer bracket 35 includes a first bracket 351 and a second bracket 352. Both the first bracket 351 and the second bracket 352 are connected to the fixed column 36. The first bracket 351 and the second bracket 352 are respectively arranged at both ends of the fixed column 36. The second end of the shock absorber strut 32 is connected to the first bracket 351, and the first bracket 351 plays a good supporting role for the shock absorber strut 32. The second end of the suspension swing arm 33 is connected to the second bracket 352, and the second bracket 352 supports the suspension swing arm 33 to ensure the stable steering of the wheel 100. The second end of the steering tie rod 34 is connected to the drive unit 40.

[0046] Under the action of the drive unit 40, the steering tie rod 34 moves to drive the connecting rod 312 to rotate, thereby realizing the steering movement of the wheel 100. During the steering process of the wheel 100, in order to maintain the stability of the wheel 100, a shock absorber strut 32 and a suspension swing arm 33 are respectively arranged at both ends of the connecting rod 312. The shock absorber strut 32 can reduce the impact of the locking mechanism 22 on the wheel 100 when the wheel 100 steers, so as to simulate the state of the wheel 100 driving smoothly. The suspension swing arm 33 plays a role of support and guidance to ensure the accurate positioning of the wheel 100, and can further improve the steering stability of the wheel 100.

[0047] The driving unit 40 is connected to the testing unit 30, and the driving unit 40 is used to provide driving force for the steering of the wheel 100. In the embodiment provided in the present application, the driving unit 40 includes a driving motor 41, a transmission mechanism 42, and a sliding mechanism 43. The first end of the sliding mechanism 43 is connected to the second end of the steering tie rod 34, and the transmission mechanism 42 is used to transmit the power of the driving motor 41 to the sliding mechanism 43; the driving motor 41 is a servo motor, and the servo motor is used to provide driving force to the transmission mechanism 42. The transmission mechanism 42 converts the rotational torque of the servo motor into the rack force and displacement of the sliding mechanism 43, and transmits the rack force and rack displacement to the wheel 100 through the sliding mechanism 43, so that the wheel 100 rotates in a state simulating driving on the road surface under the set rack force and displacement parameters.

[0048] In a feasible implementation manner, the transmission mechanism 42 is a ball screw transmission structure. The ball screw transmission mechanism 42 has the advantages of smooth movement, high transmission accuracy, long service life, etc. During the process of transmitting the driving force, it can output stably and completely, convert the rotational torque of the servo motor completely into the rack force and displacement of the sliding mechanism 43, and then transmit it to the wheel 100, so that the wheel 100 can steer under the set parameters, thereby ensuring the accuracy of the test.

[0049] In order to test, a second sensor 70 is provided between the first end of the sliding mechanism 43 and the second end of the steering tie rod 34, and a third sensor 80 is provided at the second end of the sliding mechanism 43. In the embodiment provided in the present application, the second sensor 70 is a bi-directional tension and compression force sensor, which can monitor the value of the rack force of the wheel 100 in real time during the steering process. The third sensor 80 is a linear displacement sensor, and the rack displacement value of the wheel 100 steering can be obtained through the linear displacement sensor. Both the second sensor 70 and the third sensor 80 are provided with a wire harness assembly 90, and the communication connection between the second sensor 70, the third sensor 80 and the control unit 50 is realized through the wire harness assembly 90.

[0050] The control unit 50 is connected to the wheel fixing unit 20 and the driving unit 40. The control unit 50 is used to design the parameters for the steering of the wheel 100 and test the rack force during the steering of the wheel 100. In the embodiments provided in the present application, the control unit 50 includes a test controller 51 and a computer 52. The test controller 51 is connected to the computer 52. The test controller 51 is connected to the driving unit 40 and the wheel fixing unit 20. The test controller 51 can set the steering parameters of the wheel 100 and test the rack force during the steering of the wheel 100. The control unit 50 is connected to the power supply 200. The power supply 200 provides electrical energy for the test controller 51 and the computer 52. The test controller 51 can supply power, process data, and store data for the first sensor 60, the second sensor 70, and the third sensor 80. The computer 52 is connected to the test controller 51 for communication. The computer 52 can be used as an interactive interface for parameter setting and test result display.

[0051] Referring to Figure 2 As shown in the figure, the working principle of the present invention is as follows: First, the test controller 51 sets parameters such as the rack stroke and rack displacement speed during vehicle steering to simulate the movement of the rack during vehicle steering. According to the set rack movement parameters, the servo motor is started to drive the transmission mechanism 42 to move, driving the sliding mechanism 43 to move, thereby realizing the steering movement of the wheel 100. During the steering of the wheel 100, the first sensor 60 is used to detect whether the wheel 100 is subjected to the set vertical pressure and the magnitude of the vertical pressure to ensure the smooth progress of the test. Then, the second sensor 70 and the third sensor 80 are used to monitor data such as the rack force and rack displacement to realize the test of the rack parameters.

[0052] The structure, features, and effects of the present invention have been described in detail based on the embodiments shown in the drawings. The above are only the preferred embodiments of the present invention. However, the present invention is not limited by the scope shown in the drawings. Any changes made according to the concept of the present invention, or equivalent embodiments modified into equivalent changes, still within the spirit covered by the specification and the drawings, shall be within the protection scope of the present invention.

Claims

1. A rack force test device for a steering system, It is characterized in that include: Test bench; A wheel fixing unit, the wheel fixing unit is arranged on the test bench, and the wheel fixing unit is used to carry and fix the wheel; A test unit, the test unit is connected to the wheel hub of the wheel, and the test unit is used to drive the wheel to perform steering movement; A driving unit, the driving unit is connected to the testing unit, and the driving unit is used to provide a driving force for steering the wheel; A control unit is connected to the wheel fixing unit and the driving unit, and is used to design parameters of the wheel steering and test the rack force of the wheel steering.

2. The rack force testing device for a steering system according to claim 1, It is characterized in that The wheel fixing unit comprises a lifting mechanism and a locking mechanism, the wheel is arranged on the locking mechanism, the lifting mechanism is fixed on the test bench, the locking mechanism is connected to the lifting mechanism, and the locking mechanism is used to fix the position of the lifting mechanism.

3. The rack force testing device for a steering system according to claim 2, It is characterized in that The lifting mechanism is a scissor-type lifting structure.

4. The rack force testing device for a steering system according to claim 2, It is characterized in that A first sensor is provided between the lifting mechanism and the locking mechanism.

5. The rack force testing device for a steering system according to claim 1, It is characterized in that The test unit includes a wheel hub steering knuckle, a shock absorbing strut, a suspension swing arm, a steering tie rod, an adapter bracket and a fixed column, wherein: The wheel hub steering knuckle comprises a wheel hub mounting plate and a connecting rod, wherein the wheel hub mounting plate is connected to the wheel hub of the wheel, the first end of the connecting rod is connected to the first end of the shock absorbing strut, the second end of the connecting rod is connected to the first end of the suspension swing arm, and the first end of the steering tie rod is connected to the rod body portion between the first end of the connecting rod and the second end of the connecting rod; The fixed column is arranged on the test bench, the adapter bracket includes a first bracket and a second bracket, the first bracket and the second bracket are both connected to the fixed pillar, the second end of the shock-absorbing pillar is connected to the first bracket, the second end of the suspension swing arm is connected to the second bracket, and the second end of the steering rod is connected to the drive unit.

6. The rack force testing device for a steering system according to claim 5, It is characterized in that The driving unit comprises a driving motor, a transmission mechanism and a sliding mechanism. The first end of the sliding mechanism is connected to the second end of the steering rod. The transmission mechanism is used to transmit the power of the driving motor to the sliding mechanism.

7. The rack force testing device for a steering system according to claim 6, It is characterized in that The transmission mechanism is a ball screw transmission structure.

8. The rack force testing device for a steering system according to claim 6, It is characterized in that A second sensor is provided between the first end of the sliding mechanism and the second end of the steering rod.

9. The rack force testing device for a steering system according to claim 6, It is characterized in that a third sensor is provided at the second end of the sliding mechanism.

10. The rack force testing device of the steering system according to claim 1, It is characterized in that the control unit includes a test controller and a computer, the test controller is connected to the computer, the test controller is connected to the driving unit and the wheel fixing unit, and the test controller can set the steering parameters of the wheel and test the rack force of the wheel steering.