Wheel-side bolt axial pre-tightening force detection method

Abstract

The invention discloses a wheel-side bolt axial pre-tightening force detection method. The method comprises the following steps that a chassis base is fixed to a button equipment base through bolts; the inner spigot of the chassis seat is matched with the spigot of the hub to be tested, so that the horizontal movement of the hub to be tested is limited; a threaded hole in the upper plane of the chassis seat is connected with a threaded hole of the detected hub through a positioning screw, so that rotation in the assembly process is prevented; mounting the truncated half shaft to be tested on the assembly surface of the hub to be tested, and connecting the half shaft to be tested through a bolt to be tested; the detected bolt is vertically screwed down with a set torque by using button equipment, and the axial pre-tightening force is detected. Only the tested bolt, the tested half shaft and the tested hub of the tested piece are adopted. Under specific button gun equipment, the tested half shaft is truncated, the connection characteristic of an assembly surface is not changed, only the assembly direction is changed, and the original horizontal assembly is changed into vertical assembly. According to the detection method, the detected piece is in a real assembly state, the detected axial pre-tightening force of the bolt is the actual pre-tightening force, and operation is convenient.

Description

Technical Field

[0001] This invention relates to the field of automotive parts testing, and in particular to a method for testing the axial preload of wheel bolts. Background Technology

[0002] In certain specific electric button gun devices, only vertical torque can be provided, and horizontal assembly torque cannot be achieved, which limits our ability to conduct certain torque studies.

[0003] The drive axle wheel hub has two main characteristics: 1. Individual parts of the wheel hub are relatively long, such as the axle housing assembly and half shaft; 2. In actual on-site assembly, all drive axle components are assembled in a horizontal position, not in a vertical direction. Ultrasonic testing of actual bolt preload has three key characteristics: 1. The preload is influenced by the friction coefficient of each connecting surface; 2. It is related to the actual assembly torque; 3. It is related to the bolt's design diameter, bolt material, and bolt mechanical strength grade.

[0004] This application provides a method for detecting the axial preload of wheel-side bolts, based on existing technical problems. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method for detecting the axial preload of wheel bolts.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for detecting the axial preload of wheel-side bolts includes the following steps: Secure the chassis to the base of the switch device using bolts; The horizontal movement of the wheel hub is restricted by the inner stop of the chassis base engaging with the stop of the wheel hub being tested. Use positioning screws to connect the threaded holes on the upper surface of the chassis base to the threaded holes on the wheel hub being tested, to prevent rotation during assembly. The shortened half-shaft to be tested is installed onto the mounting surface of the hub to be tested and connected by the bolts to be tested. Use a button device to vertically tighten the bolt under test with a set torque to detect the axial preload.

[0007] Furthermore, the half-shaft being tested needs to be shortened to a length less than the height of the wheel hub being tested, while retaining the original assembly end face structure.

[0008] Furthermore, only the tested bolts, the tested half-shaft, and the tested wheel hub are used for assembly, excluding other irrelevant parts.

[0009] Furthermore, the chassis base is configured as follows: It is disc-shaped with a hollow structure in the middle and a height greater than the height of the wheel hub being measured. The bottom is connected to the equipment base by at least four bolts. The inner wall is provided with a stop that matches the stop of the wheel hub being tested; The upper surface has two threaded holes, which are connected to the threaded holes of the wheel hub being tested by positioning screws.

[0010] Furthermore, the internal space height of the hollow structure is greater than 200mm to avoid interference with the wheel hub.

[0011] Furthermore, the length of the half-shaft being tested is shortened to 300mm-500mm to ensure that it is compatible with the vertical travel of the push-button device, which is ≤600mm.

[0012] Furthermore, the half-shaft cross-section is not involved in the assembly; only the original assembly end face is retained to ensure that the coefficient of friction remains unchanged.

[0013] Furthermore, the tested wheel hub directly reuses its original stop and threaded hole structure without any processing or modification.

[0014] Furthermore, the assembly direction is changed from horizontal to vertical, and the positioning structure of the chassis base ensures that the stress state of the assembly surface is consistent with the actual horizontal assembly.

[0015] The beneficial effects of this invention are as follows: This invention only uses the tested bolt, the tested half-shaft, and the tested hub. Using a specific ultrasonic testing device, the tested half-shaft is shortened without changing the connection characteristics of the assembly surface; only the assembly direction is changed from horizontal to vertical. Under this testing method, the tested part is in a true assembled state, and the detected axial preload of the bolt is the actual preload, making operation convenient. Simultaneously, this ultrasonic testing technology significantly improves the design reliability, safety, and process controllability of the product. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the assembly cross-section of the drive axle wheel side structure; Figure 2 This is a schematic diagram of the assembly cross-section of the test piece in the vertical direction. Figure 3 This is a schematic diagram of the chassis base. Figure 4 This is a schematic diagram of the structure of the wheel hub being tested; Figure 5 This is a schematic diagram of the structure after the half-shaft under test has been cut off. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Reference Figure 1 The existing drive axle wheel-side structure consists of: bolt 1-1 connecting half-shaft 2-2 and wheel hub 3-3, with half-shaft 2-2 typically 800mm to 900mm in length; screw 4 connecting wheel hub 3-3 and brake drum 5; brake base plate bolt 7 connecting brake 6 and axle housing assembly 8, with axle housing assembly 8 typically 1800mm to 2000mm in length; and double-row tapered bearing 9 supporting wheel hub 3-3 and axle housing assembly 8, enabling the drive axle wheel-side rotation function. As can be seen, all components of the drive axle are connected via bolts, making the reliability of these bolt connections crucial.

[0019] To ensure a reliable bolt connection, it is necessary to determine the magnitude of the bolt's axial preload. To measure the actual bolt preload, the following three issues must be addressed: 1) Under certain specific electric button gun devices, only vertical torque can be provided, and horizontal assembly torque cannot be achieved; 2) Half shaft 2-2 and axle housing assembly 8 are too long and cannot be used on a specific torque gun device to perform the set torque assembly. The vertical stroke on a specific torque gun device is only 600mm. 3) The axial preload of the bolts is related to the friction coefficient of the contact surfaces of each component and must be tested on the actual assembled parts. For example, to test the axial preload of bolt 1-1, it is necessary to assemble two parts: half-shaft 2-2 and hub 3-3.

[0020] like Figures 2 to 5 A novel method for detecting the axial preload of wheel-side bolt assembly includes a chassis base 1, a positioning screw 2, a bolt to be tested 1-1, a half-shaft to be tested 2-2, a wheel hub to be tested 3-3, and an electric button device 3.

[0021] The chassis base 1 is connected and fixed to the base of the electric button device using four bolts. The inner stop design of the chassis base 1 is designed to mate with the stop of the hub 3-3 to prevent left and right movement. The two threaded holes on the upper surface of the chassis base 1 are connected to the original two threaded holes of the hub 3-3 using positioning screws 2 to prevent the tested part from rotating during assembly. The tested half-shaft 2-2, after being shortened, is installed on the mounting surface of the tested hub 3-3 according to its original assembly, and then connected with the tested bolt 1-1. The tested bolt 1-1 is tightened using the torque set by the electric button gun. Furthermore, the base plate 1 is designed in a disc shape and is connected to the equipment base with 4 bolts. The inner stop is designed to match the stop of the hub 3-3 to prevent left and right movement. The upper surface is designed with two threaded holes, which are connected to the two threaded holes of the hub 3-3 for positioning. The hollow height in the middle is greater than the height of the hub being measured, so as not to interfere.

[0022] Furthermore, the test hub 3-3 utilizes the existing stop and positioning threaded hole to test the test threaded hole, without changing the overall state of the test hub 3-3.

[0023] Furthermore, the tested half-shaft 2-2 is cut off, with its length shorter than the height of the tested hub 3-3, while other surfaces remain unchanged, thus not altering the friction coefficient of the assembly surface.

[0024] This testing method only uses the tested bolt 1-1, the tested half-shaft 2-2, and the tested hub 3-3; other unrelated components are not used. Under a specific ultrasonic testing device, the tested half-shaft 2-2 is shortened. The connection characteristics of the assembly surface are not changed; only the assembly direction is altered from horizontal to vertical. Under this testing method, the tested parts are in a true assembled state, and the detected axial preload of the bolt is the actual preload. Simultaneously, this ultrasonic testing technology significantly improves the product's design reliability, safety, and process controllability.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the axial preload of wheel-side bolts, characterized in that, Includes the following steps: Secure the chassis to the base of the switch device using bolts; The horizontal movement of the wheel hub is restricted by the inner stop of the chassis base engaging with the stop of the wheel hub being tested. Use positioning screws to connect the threaded holes on the upper surface of the chassis base to the threaded holes on the wheel hub being tested, to prevent rotation during assembly. The shortened half-shaft to be tested is installed onto the mounting surface of the hub to be tested and connected by the bolts to be tested. Use a button device to vertically tighten the bolt under test with a set torque to detect the axial preload.

2. The detection method according to claim 1, characterized in that: The half-shaft being tested needs to be shortened to a length less than the height of the wheel hub being tested, while retaining the original assembly end face structure.

3. The detection method according to claim 1, characterized in that: Assembly is performed using only the bolts, half-shafts, and hubs being tested, excluding other irrelevant components.

4. The detection method according to claim 1, characterized in that: The chassis base is configured as follows: It is disc-shaped with a hollow structure in the middle and a height greater than the height of the wheel hub being measured. The bottom is connected to the equipment base by at least four bolts. The inner wall is provided with a stop that matches the stop of the wheel hub being tested; The upper surface has two threaded holes, which are connected to the threaded holes of the wheel hub being tested by positioning screws.

5. The detection method according to claim 4, characterized in that: The internal space height of the hollow structure is greater than 200mm to avoid interference with the wheel hub.

6. The detection method according to claim 1, characterized in that: The length of the half-shaft being tested after being shortened is 300mm-500mm to ensure that it is compatible with the vertical stroke of the push-button device ≤600mm.

7. The detection method according to claim 1, characterized in that: The half-shaft cross-section is not involved in the assembly; only the original assembly end face is retained to ensure that the coefficient of friction remains unchanged.

8. The detection method according to claim 1, characterized in that: The tested wheel hub directly reuses its original stop and threaded hole structure without any processing or modification.

9. The detection method according to claim 1, characterized in that: The assembly direction changes from horizontal to vertical, and the positioning structure of the chassis base ensures that the stress state of the assembly surface is consistent with the actual horizontal assembly.

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