Novel commercial vehicle electric power steering gear test bench

Abstract

The utility model discloses a novel commercial vehicle electric power steering gear test bench, which is characterized in that the novel commercial vehicle electric power steering gear test bench comprises a servo motor assembly, a torque transmission assembly and a mechanical support assembly, the servo motor assembly comprises a servo motor and a multi-stage speed reducer, and an output shaft of the servo motor is connected with an input end of the multi-stage speed reducer through a coupler; the torque transmission assembly comprises a tested electric power steering gear mounting bracket and an output shaft connecting flange, and the output end of the multi-stage speed reducer is connected with an output shaft of the tested electric power steering gear through the output shaft connecting flange; the mechanical supporting assembly comprises a base frame, a damping device and an adjustable steering wheel support, the servo motor assembly, the tested electric power steering gear installation support and the adjustable steering wheel support are fixed to the base frame, and the damping device is arranged at the bottom of the base frame.

Description

Technical Field

[0001] This utility model relates to the field of steering technology, and in particular to a novel test bench for electric power steering systems in commercial vehicles. Background Technology

[0002] Electric power steering (EPS) systems in commercial vehicles typically undergo road and bench tests after vehicle assembly to verify their functionality and reliability. Real-vehicle testing provides data on steering torque, steering angle, and response time under actual road conditions, but it is time-consuming, costly, and difficult to perform and repeat under extreme or hazardous conditions. Existing commercial vehicle steering benches primarily target hydraulic or electro-hydraulic power steering systems, using hydraulic motors or electric motors with dampers to simulate ground resistance and test the steering system's durability and reliability. Some early EPS benches focused solely on durability testing, using high-power motors and simple friction load devices, which could not accurately control or measure instantaneous torque, resulting in average or extreme durability data. While a few EPS functional benches exist for passenger vehicles, most have limited output torque ranges, failing to cover the high torque conditions required for commercial vehicles. The power assist and self-centering characteristics of commercial vehicle EPS under high load and high torque conditions have not yet been quantitatively calibrated using a dedicated high-precision bench.

[0003] Therefore, it is necessary to provide a new type of test bench for electric power steering systems in commercial vehicles to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0005] In view of the aforementioned existing problems, this utility model is proposed.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a novel test bench for electric power steering (EPS) systems in commercial vehicles, characterized in that it includes a servo motor assembly, a torque transmission assembly, and a mechanical support assembly. The servo motor assembly includes a servo motor and a multi-stage reducer, and the output shaft of the servo motor is connected to the input end of the multi-stage reducer via a rigid coupling. The torque transmission assembly includes a mounting bracket for the EPS system under test and an output shaft connecting flange, and the output end of the multi-stage reducer is rigidly connected to the output shaft under test via the output shaft connecting flange. The mechanical support assembly includes a base frame, a vibration damping device, and an adjustable steering wheel bracket. The servo motor assembly, the EPS mounting bracket, and the adjustable steering wheel bracket are fixed on the base frame, and the vibration damping device is disposed at the bottom of the base frame.

[0007] As a preferred embodiment of the new commercial vehicle electric power steering test bench of this utility model, the multi-stage reducer is fixedly mounted on the base frame by bolts.

[0008] As a preferred embodiment of the new commercial vehicle electric power steering test bench of this utility model, the rigid coupling is a diaphragm coupling, and its two ends are rigidly connected to the output shaft of the servo motor and the input shaft of the multi-stage reducer through flanges respectively.

[0009] As a preferred embodiment of the new commercial vehicle electric power steering test bench of this utility model, the EPS mounting bracket under test includes a U-shaped clamp and a quick locking mechanism, and the inner side of the U-shaped clamp is provided with a rubber buffer pad.

[0010] As a preferred embodiment of the novel commercial vehicle electric power steering test bench of this utility model, the adjustable steering wheel bracket includes a slide rail, a height adjustment rod, and a clamp. The slide rail is arranged horizontally along the base frame, and the clamp is slidably connected to the slide rail through the height adjustment rod for fixing steering wheels of different diameters.

[0011] As a preferred embodiment of the novel commercial vehicle electric power steering test bench of this utility model, the vibration damping device is a rubber damping pad, which is evenly distributed at the four corners of the base frame.

[0012] As a preferred embodiment of the new commercial vehicle electric power steering test bench of this utility model, the output shaft connecting flange is a split flange, including a fixed flange and a movable flange. The movable flange is connected to the output shaft, and an anti-loosening pin is provided between the two.

[0013] As a preferred embodiment of the new commercial vehicle electric power steering test bench of this utility model, the base frame is welded from rectangular steel pipes.

[0014] As a preferred embodiment of the test bench for the new commercial vehicle electric power steering system described in this utility model, the output end of the multi-stage reducer is provided with a torque sensor mounting interface, which is used to fix an external torque sensor.

[0015] As a preferred embodiment of the new commercial vehicle electric power steering test bench of this utility model, the servo motor housing is provided with heat dissipation fins on both sides and is isolated from the base frame by heat insulation pads.

[0016] The beneficial effects of this invention are as follows: The test bench can simulate various typical working conditions under both manual and automatic driving steering modes, including basic power assist function testing, return-to-center function testing, and safety redundancy function testing, meeting the verification needs of EPS performance and reliability in different application scenarios. Through a servo system, the ground resistance changes during steering are accurately simulated, and signals such as steering angle, angular velocity, torque, and vehicle speed can be precisely controlled and collected, making the test environment standardized and repeatable, providing reliable support for the development, verification, and performance comparison of EPS systems. The test bench supports rapid switching of test conditions and fault simulation, independent of the vehicle or actual road conditions, and reserves multiple signal interfaces and functional expansion modules, flexibly adapting to EPS systems of different specifications and control logics, resulting in strong system scalability. The diaphragm coupling, split flange, and reinforced base frame ensure lag-free torque transmission, improving the accuracy of test data. The adjustable steering wheel bracket and EPS mounting bracket support rapid installation of multiple equipment models. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0018] Figure 1 A schematic diagram of a novel commercial vehicle electric power steering test bench according to one embodiment of this utility model. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0020] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] Example 1

[0023] Reference Figure 1According to an embodiment of this utility model, a novel test bench for electric power steering (EPS) in commercial vehicles is characterized by comprising a servo motor assembly, a torque transmission assembly, and a mechanical support assembly. The servo motor assembly includes a servo motor and a multi-stage reducer, with the output shaft of the servo motor connected to the input end of the multi-stage reducer via a rigid coupling. The torque transmission assembly includes a mounting bracket for the EPS under test and an output shaft connecting flange, with the output end of the multi-stage reducer rigidly connected to the output shaft of the EPS under test via the output shaft connecting flange. The mechanical support assembly includes a base frame, a vibration damping device, and an adjustable steering wheel bracket. The servo motor assembly, the EPS mounting bracket, and the adjustable steering wheel bracket are fixed on the base frame, and the vibration damping device is located at the bottom of the base frame. Specifically, the multi-stage reducer is bolted to the base frame. The multi-stage reducer is fixed to the base frame with high-strength bolts, and the machining accuracy of the contact surface between its outer shell and the base frame is ≤0.05mm, ensuring that the coaxiality error between the reducer input end and the servo motor is ≤0.03mm, thereby reducing vibration and energy loss during torque transmission. The rigid coupling is a diaphragm coupling, with its two ends rigidly connected to the output shaft of the servo motor and the input shaft of the multi-stage reducer via flanges. The diaphragm coupling is made of stainless steel, and its flexible diaphragm structure can compensate for axial ±0.2mm and radial ±0.1mm installation deviations, while suppressing high-frequency vibration transmission to the EPS under test (electric power steering), thus avoiding mechanical interference with the test data. The EPS mounting bracket includes a U-shaped clamp and a quick-locking mechanism. The U-shaped clamp has a rubber buffer pad on its inner side. The rubber buffer pad on the inner side of the U-shaped clamp has a Shore A hardness of 60A, which can evenly distribute the clamping force during locking, preventing deformation of the EPS housing. The quick-locking mechanism uses a ratchet handle, allowing for single-operation fixing, and is suitable for EPS housings with diameters ranging from 200 to 400mm, reducing installation time to less than 30 seconds. The adjustable steering wheel bracket includes a slide rail, a height adjustment rod, and a clamp. The slide rail is horizontally arranged along the base frame, and the clamp is slidably connected to the slide rail (801) via the height adjustment rod (802) for fixing steering wheels of different diameters. The slide rail (801) is chrome-plated with a friction coefficient ≤0.1. The height adjustment rod adopts a trapezoidal thread structure with an adjustment accuracy of 2mm per turn. The clamp has embedded silicone anti-slip pads and can fix steering wheels with diameters of 300-600mm, covering the needs of mainstream commercial vehicle models and improving test preparation efficiency by 50%. The vibration damping device is a rubber damping pad, evenly distributed at the four corners of the base frame. The rubber damping pads are evenly distributed at the four corners of the base, with a single damping pad compression deformation ≤2mm and a hardness of 70A, which can reduce the vibration amplitude of the test bench, effectively isolate the vibration of the servo motor and reducer during operation, and ensure that the measurement accuracy of the torque sensor is not interfered with.The output shaft connection flange is a split flange, including a fixed flange and a movable flange. The movable flange is connected to the output shaft, and an anti-loosening pin is provided between the two. The movable flange of the split flange is connected to the output shaft of the EPS under test via a spline, with a spline tooth clearance ≤0.05mm. The anti-loosening pin is made of spring steel and, after insertion, has an interference fit with the flange hole to prevent the flange from detaching due to sudden torque changes during testing, ensuring test safety. The base frame is welded from Q235 carbon steel rectangular tubing with a wall thickness of 5mm. The top is welded with reinforcing ribs at a density of 4 per square meter, significantly improving overall rigidity compared to traditional frames. The maximum load capacity reaches 20 tons, meeting the high-strength testing requirements of commercial vehicle EPS. The top is equipped with reinforcing ribs, with a distribution density of ≥3 per square meter. The output end of the multi-stage reducer is equipped with a torque sensor mounting interface for fixing an external torque sensor. The surface of the torque sensor mounting interface is nickel-plated for rust prevention, ensuring coaxiality between the sensor and the reducer output end, while also improving data acquisition accuracy. The servo motor has heat dissipation fins on both sides of its housing, and these fins are isolated from the base frame by thermal insulation pads. The heat dissipation fins of the servo motor are spaced 5mm apart, and the thermal insulation pads are made of ceramic fiber to prevent heat from the motor from being conducted to the base frame, thus avoiding structural deformation due to thermal expansion that could affect test accuracy.

[0024] Servo Motor Assembly: The servo motor is connected to a multi-stage reducer via a diaphragm coupling. The motor's output torque is amplified by the reducer and transmitted to the EPS under test. The reducer housing is fixed to the base frame with high-strength bolts to ensure rigid power transmission. Torque Transmission Assembly: The EPS under test is fixed to the mounting bracket with U-shaped clamps and a quick-locking mechanism. The output shaft is rigidly connected to the reducer output end via a split flange, and anti-loosening pins prevent the flange from detaching during testing. Mechanical Support Assembly: The rectangular steel tube welded structure and reinforcing ribs of the base frame provide rigid support. Rubber shock-absorbing pads are evenly distributed at the four corners of the base to suppress vibrations during the operation of the servo motor and reducer. The adjustable steering wheel bracket adjusts the steering wheel position via slide rails and a height adjustment rod to adapt to the testing needs of different vehicle models.

[0025] Test procedure: (1) Install the EPS under test: Place the EPS housing into the U-shaped clamp and fix it by the quick locking mechanism. Connect the output shaft to the movable flange. (2) Adjust the steering wheel bracket: Slide the clamp to the target position and adjust the height adjustment rod to align the steering wheel with the EPS input shaft. (3) Start the servo motor: Drive the servo motor through the external control signal to simulate different steering loads. The torque sensor collects the output data in real time. (4) Data analysis: Combine the feedback from the angle sensor (encoder) and the torque sensor to evaluate the power assist performance, self-centering characteristics and redundancy function of the EPS.

[0026] First, the power supply subsystem provides a stable operating voltage to all modules inside the test bench and the EPS device under test, ensuring normal system operation. After system startup, the control subsystem loads the preset test program and sends control commands to the servo simulation subsystem according to the set operating parameters.

[0027] The servo simulation subsystem generates a simulated steering load of a certain magnitude and direction through a servo motor. After passing through a reduction mechanism, this load is applied to the output shaft of the EPS under test, thus creating a load environment similar to the steering resistance of an actual road. Based on signals from the steering sensor, vehicle control commands, and other sources, the EPS under test outputs corresponding assist torque to drive the steering wheel to rotate.

[0028] Throughout the process, the measurement subsystem collects key parameters in real time, such as steering wheel angle, power steering motor output torque, servo motor load torque, and system response time. This data is processed by the signal conditioning module and then transmitted to the control subsystem for real-time monitoring, data recording, and comprehensive evaluation of EPS control performance.

[0029] Meanwhile, the test bench system is equipped with a fault protection mechanism. When abnormal power supply, overload, or abnormal signal is detected, it can quickly perform an emergency shutdown operation to ensure the safety of personnel and equipment.

[0030] Through the above workflow, the test bench can comprehensively and systematically test the power assist characteristics, self-centering performance, and redundant control response of EPS under different steering conditions, providing a reliable test platform for EPS product development and performance verification.

[0031] In summary, this invention can accurately simulate ground resistance and form closed-loop torque feedback within the output torque range of 0 to 10,000 N·m, supporting high-precision and repeatable calibration and verification of the "basic assist-return-safety redundancy" function in both manual and automatic driving modes, thereby significantly shortening the development cycle and improving test safety and data reliability.

[0032] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of this utility model. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structural equivalents but also equivalent structures. Without departing from the scope of this invention, other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments. Therefore, this invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0033] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the present invention as currently considered, or those features that are not relevant to the implementation of the present invention) may be omitted.

[0034] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0035] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A novel test bench for electric power steering systems in commercial vehicles, characterized in that, The system includes a servo motor assembly, a torque transmission assembly, and a mechanical support assembly. The servo motor assembly includes a servo motor and a multi-stage reducer, with the output shaft of the servo motor connected to the input end of the multi-stage reducer via a coupling. The torque transmission assembly includes a mounting bracket for the tested electric power steering system and an output shaft connecting flange, with the output end of the multi-stage reducer connected to the output shaft of the tested electric power steering system via the output shaft connecting flange. The mechanical support assembly includes a base frame, a vibration damping device, and an adjustable steering wheel bracket. The servo motor assembly, the mounting bracket for the tested electric power steering system, and the adjustable steering wheel bracket are fixed on the base frame, and the vibration damping device is located at the bottom of the base frame.

2. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The multi-stage reducer is fixedly mounted on the base frame by bolts.

3. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The coupling is a diaphragm coupling, with its two ends rigidly connected to the output shaft of the servo motor and the input shaft of the multi-stage reducer via flanges.

4. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The mounting bracket for the tested electric power steering system includes a U-shaped clamp and a quick-locking mechanism, with a rubber buffer pad on the inner side of the U-shaped clamp.

5. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The adjustable steering wheel bracket includes a slide rail, a height adjustment rod, and a clamp. The slide rail is arranged horizontally along the base frame, and the clamp is slidably connected to the slide rail via the height adjustment rod to fix steering wheels of different diameters.

6. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The vibration damping device is a rubber damping pad, which is evenly distributed at the four corners of the base frame.

7. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The output shaft connecting flange is a split flange, including a fixed flange and a movable flange. The movable flange is connected to the output shaft, and an anti-loosening pin is provided between the two.

8. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The base frame is welded from rectangular steel pipes.

9. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The output end of the multi-stage reducer is provided with a torque sensor mounting interface, which is used to fix an external torque sensor.

10. The novel commercial vehicle electric power steering test bench according to claim 1, characterized in that, The servo motor has heat dissipation fins on both sides of its housing, and is isolated from the base frame by heat insulation pads.

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