A machining process for passenger car forged wheel hubs
By employing a step-by-step processing technique and a multi-positioning and loosening method, the problems of deformation in milled windows and out-of-tolerance assembly dimensions in forged wheel hubs were solved, achieving efficient and precise wheel hub processing, improving yield, and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CITIC DICASTAL CO LTD
- Filing Date
- 2024-07-30
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies for forging wheel hub processing, especially in the process of milling windows, suffer from severe deformation and out-of-tolerance assembly dimensions. This is particularly problematic in the new energy vehicle market, where there is a demand for complex window designs, and existing methods are insufficient to effectively address the issues of deformation and assembly accuracy.
The process involves a step-by-step machining process, including rough turning of the positioning surface, rough turning of the front of the wheel hub, rough milling and finish milling of the window, finish turning of the inner rim and center hole, finish turning of the outer rim and front of the wheel hub, drilling of bolt holes and valve holes. The machining allowance is reserved based on the window shape and deformation parameters to avoid deformation caused by milling to the finished surface in one clamping. The accuracy and balance are ensured by positioning and releasing the semi-finished wheel hub multiple times.
This effectively avoids wheel hub deformation and assembly dimensional deviations caused by milling windows, significantly improves the yield rate, reduces safety hazards, improves the balance characteristics and assembly effect of the wheel hub, increases processing efficiency, and reduces production costs.
Smart Images
Figure CN118578073B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of forged passenger car wheel hub processing, and particularly to a machining process for forged passenger car wheel hubs. Background Technology
[0002] Before milling, when the wheel hub is in a blank state or the inner rim is finished by precision machining, the window position of the forged wheel hub for passenger vehicles is generally solid and closed, and the machining amount at the window position is usually the largest. During the subsequent milling of the window, as the material is gradually removed, the stress at various positions is released, which can lead to rim deformation and runout exceeding tolerance. It can even cause important assembly dimensions such as the center hole of the wheel hub to gradually exceed tolerance as the stress is released.
[0003] Currently, in the processing of forged wheel hubs for passenger vehicles, the process involves first machining to the finished product rotation line, and then using the machined surface as a positioning reference to mill the window, which is highly efficient. However, with the rapid growth of the new energy vehicle market, the window shape of forged wheel hubs is becoming more and more complex, and the performance requirements are also becoming higher and higher, resulting in more and more severe deformation when milling the window.
[0004] The following are some common wheel hub machining methods: One method is to first machine the blank directly to the wheel hub finishing line, and then mill the window. This machining process is highly efficient, but as the material is gradually removed during the milling process, the stress on the spokes is released, which will eventually lead to rim deformation, runout exceeding tolerance, and may even affect some important assembly dimensions such as the center hole size and flange flatness, thus seriously reducing the machining yield.
[0005] Another method is to pre-drill holes in the spokes of the blank before heat treatment. Although this method improves the deformation problem during subsequent milling of the window to some extent, the effect is minimal. Due to the influence of the wheel hub window shape, the amount of milling work at the window position of the blank after pre-drilling is still very large, and the deformation problem still exists after milling. This is especially true for some wheel hubs with complex window shapes, where the improvement effect of pre-drilling is even worse.
[0006] Another less common method is to forge the wheel hub window directly without further milling. Although this method can effectively solve the deformation problem during the machining process of forged wheel hubs, it has very high technical requirements for the forging process. Especially for some wheel hubs with complex window shapes and high surface condition requirements, this method has a very low yield and may even be impossible to produce. Summary of the Invention
[0007] To address the aforementioned technical problems, this invention proposes a machining process for forged wheel hubs for passenger vehicles, comprising the following steps: 101. Rough turning of the positioning surface: The outer rim side lip end face of the wheel hub blank is brought into contact with the end face block of the fixture, and the axial positioning of the wheel hub blank is completed with the help of the pressure claw. The radial positioning of the wheel hub blank is completed by using 3 or 4 evenly arranged radial blocks to contact the rim of the blank. After positioning, the rim, the back of the spokes, and the center hole are rough turned. After rough turning, a semi-finished wheel hub is obtained.
[0008] 102. Roughing the front of the wheel hub: The inner rim side lip end face after the roughing process in step 101 is brought into contact with the end face block of the fixture. The clamping jaws are used to complete the axial positioning of the semi-finished wheel hub. The mandrel is used to complete the radial positioning of the semi-finished wheel hub by cooperating with the center hole after the roughing process in step 101. After positioning, the outer rim and the front of the wheel hub are rough-machined.
[0009] 103. Rough milling and finish milling of windows: After positioning the semi-finished wheel hub using the same positioning method as in 102, rough mill the windows. After rough milling, release the semi-finished wheel hub and then position it again. After positioning, finish mill the windows and cap grooves.
[0010] 104. Finish turning the inner rim and center hole: After the rough turning process in 102, the outer rim side lip end face is brought into contact with the fixture end face block. The clamping jaws are used to complete the axial positioning of the semi-finished wheel hub. The radial positioning of the semi-finished wheel hub is completed by the cooperation of the tapered mandrel and the precision milled cap groove. After positioning, the inner rim, the back of the spokes, and the center hole position are finished to the finished product line.
[0011] 105. Precision machining of the outer rim and front of the hub: The inner rim side lip end face after the precision machining process in step 105 is brought into contact with the end face block of the fixture. The axial positioning of the semi-finished hub is completed with the cooperation of the pressure claw. The radial positioning of the semi-finished hub is completed by the cooperation of the mandrel with the center hole after the previous precision machining. After positioning, the outer rim, front of the hub and the position of the cap groove are precision machined.
[0012] 106. Drilling bolt holes and valve holes: When axially positioning the semi-finished wheel hub, the same method as in 105 is adopted. The circumferential positioning of the semi-finished wheel hub is completed by using the positioning rod and window cooperation or by using image recognition. After positioning, the valve holes and bolt holes are machined to complete the machining of the wheel hub and obtain the finished wheel hub.
[0013] Preferably, during the rough turning processes in 101 and 102, machining allowance is reserved for the finish turning processes in 104 and 105, taking into account the window shape and deformation size parameters.
[0014] Preferably, during the rough milling process in step 103, the amount of machining allowance is reserved for the finish milling process in step 103, taking into account the deformation amount after the stress of the wheel hub is released during the rough milling process.
[0015] The beneficial effects of this invention compared with the prior art are: (1) In the processing technology provided by this invention, the processing of key assembly positions such as the center hole, cap groove, flange mounting surface, and rim of the wheel hub are all placed after milling the window, which largely avoids the problem of wheel hub size deviation caused by blank deformation after milling the window, and greatly reduces safety hazards; (2) The processing technology provided by this invention effectively improves the problems of wheel hub and rim jump failure, window deformation, and balance deviation caused by stress release during the milling of the window in the machining process of passenger car forged wheel hubs; (3) In the processing technology provided by this invention, after rough milling the window, the wheel hub semi-finished product is first released, and then the wheel hub semi-finished product is repositioned; This solves the problem in the prior art that the window shape is severely deformed after the wheel hub is released from the fixture after fine milling due to direct milling to the finished surface in one clamping, which affects the balance characteristics of the wheel hub, especially for passenger car wheel hubs with installed plugs, decorative rings, etc. (4) In the processing technology provided by the present invention, when performing the rough turning process, the processing amount is reserved for the finishing turning process in combination with the window shape and deformation size parameters; this avoids the risk that the wheel rim will deform as the milling window is gradually removed due to the small reserved processing amount in the prior art, resulting in no processing amount in the finishing turning process; at the same time, it avoids the problem that the wheel spoke thickness is too thick after rough turning due to the large reserved processing amount, which affects the subsequent milling processing efficiency and increases production costs; (5) In the processing technology provided by the present invention, the processing amount is reserved in combination with the window shape and deformation size parameters when performing the finishing milling process; this avoids the problem that the wheel hub will have serious deformation after the finishing milling is completed and released from the fixture due to the large reserved amount in the rough milling, resulting in a large difference between the final window shape and the theoretical shape; at the same time, it avoids the problem that the wheel hub will deform after the stress is released due to the small reserved amount in the rough milling, resulting in a lack of material during the finishing milling. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall process of the present invention.
[0017] Figure 2 This is a schematic diagram of the rough machining positioning surface process of the present invention.
[0018] Figure 3 This is a schematic diagram of the front process of the rough wheel hub of the present invention.
[0019] Figure 4 This is a schematic diagram of the milling process of the present invention.
[0020] Figure 5 This is a schematic diagram of the precision machining process of the inner rim of the present invention.
[0021] Figure 6 This is a schematic diagram of the precision machining process of the outer rim of the present invention.
[0022] Figure 7 This is a schematic diagram of the drilling process of the present invention. Detailed Implementation
[0023] The present invention will be further described below with reference to specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.
[0024] Example: Figures 1-7 The machining process for a forged wheel hub for passenger vehicles shown includes the following steps: 101. Rough turning of the positioning surface: The outer rim side lip end face of the wheel hub blank is brought into contact with the end face block of the fixture, and the axial positioning of the wheel hub blank is completed with the help of the pressure claw. The radial positioning of the wheel hub blank is completed by using 3 or 4 evenly arranged radial blocks to contact the rim of the blank. After positioning, the rim, the back of the spokes, and the center hole are rough turned. After rough turning, a semi-finished wheel hub is obtained.
[0025] 102. Roughing the front of the wheel hub: The inner rim side lip end face after the roughing process in step 101 is brought into contact with the end face block of the fixture. The axial positioning of the wheel hub semi-finished product is completed with the help of the pressure claw. The radial positioning of the wheel hub semi-finished product is completed by using the mandrel and the center hole after the roughing process in step 101. After positioning, the front of the outer rim and the wheel hub is rough-machined.
[0026] 103. Rough Milling and Finish Milling of the Window: After positioning the semi-finished wheel hub using the same positioning method as in 102, rough mill the window. After rough milling, release the semi-finished wheel hub and then reposition it. If the wheel hub is milled directly to the finished surface in one clamping, the window shape will be severely deformed after the finish milling is completed and the wheel hub is released from the fixture, which will affect the balance characteristics of the wheel hub. This is especially true for passenger car wheel hubs with inserts or decorative rings, which will seriously affect their assembly effect. After positioning, finish mill the window and the cap groove. After finish milling the window, the cap groove attachment position needs to be milled simultaneously. It should be noted that the cap groove position is not milled to the finished surface, but rather a reasonable allowance is left according to the actual situation to ensure sufficient machining allowance when finishing the cap groove later.
[0027] 104. Finish turning the inner rim and center hole: After rough turning in step 102, the outer rim side lip end face is brought into contact with the fixture end face block, and the clamping jaws are used to complete the axial positioning of the semi-finished wheel hub; the radial positioning of the semi-finished wheel hub is completed by the cooperation of the tapered mandrel and the precision milled cap groove, which can improve the synchronization of the relative position of the rim and the window and improve the balance characteristics of the wheel hub; after positioning, finish turning the inner rim, the back of the spokes, and the center hole position to the finished product line.
[0028] 105. Precision machining of the outer rim and front of the hub: The inner rim side lip end face after the precision machining process in step 105 is brought into contact with the end face block of the fixture. The axial positioning of the semi-finished hub is completed with the cooperation of the pressure claw. The radial positioning of the semi-finished hub is completed by the cooperation of the mandrel with the center hole after the previous precision machining. After positioning, the outer rim, front of the hub and the position of the cap groove are precision machined.
[0029] 106. When axially positioning the semi-finished wheel hub, the same method as in 105 is adopted, using the positioning rod and window cooperation or image recognition to complete the circumferential positioning of the semi-finished wheel hub; after positioning, the valve hole and bolt hole are machined to complete the machining of the wheel hub and obtain the finished wheel hub.
[0030] During the rough turning processes in steps 101 and 102, a machining allowance is reserved for the finish turning processes in steps 104 and 105, taking into account the window shape and deformation parameters. That is, when rough turning the wheel hub, a certain machining allowance must be reserved for subsequent finish turning. If the reserved machining allowance is too small, the wheel rim will deform to a certain extent as the milling of the window gradually removes material, which may result in no machining allowance for the finish turning process. If the reserved machining allowance is too large, that is, the wheel spoke thickness is too thick after rough turning, it will affect the efficiency of subsequent milling and increase production costs. Therefore, when performing the rough turning processes in steps 101 and 102 of the wheel hub design, it is necessary to reasonably design the reserved allowance by taking into account parameters such as the window shape and deformation size.
[0031] During the rough milling process in step 103, the amount of deformation after the stress release of the wheel hub is taken into account to reserve machining allowance for the finish milling process in step 103. That is, when milling the wheel hub after rough milling, rough milling is performed first. After rough milling, the wheel hub needs to be released from the fixture and then clamped again before finish milling can begin. If the rough milling allowance is too large, the wheel hub will deform severely after being released from the fixture after finish milling, resulting in a significant difference between the final window shape and the theoretical shape. If the rough milling allowance is too small, the wheel hub will deform after the stress release, resulting in insufficient material during finish milling. Therefore, during rough milling, a reasonable design allowance is crucial to the balance characteristics of the wheel hub.
Claims
1. A machining process for forged wheel hubs for passenger vehicles, characterized in that, Includes the following steps:
101. Rough turning of positioning surfaces: The outer rim side lip end face of the wheel hub blank is brought into contact with the end face block of the fixture, and the axial positioning of the wheel hub blank is completed with the help of the pressure claw. The radial positioning of the wheel hub blank is completed by using 3 or 4 evenly arranged radial blocks to contact the rim of the blank. After positioning, the rim, the back of the spokes, and the center hole are rough turned. After rough turning, a semi-finished wheel hub is obtained.
102. Roughing the front of the wheel hub: The inner rim side lip end face after the roughing process in step 101 contacts the end face block of the fixture, and the clamping jaws are used to complete the axial positioning of the wheel hub semi-finished product. The mandrel is used to complete the radial positioning of the wheel hub semi-finished product by cooperating with the center hole after the roughing process in step 101. After positioning, the outer rim and the front of the wheel hub are rough-machined.
103. Rough milling and finish milling of windows: After positioning the semi-finished wheel hub using the same positioning method as in 102, rough mill the windows. After rough milling, release the semi-finished wheel hub and then position it again. After positioning, finish mill the windows and cap grooves.
104. Finish turning the inner rim and center hole: After rough turning in step 102, the outer rim side lip end face is brought into contact with the fixture end face block. The clamping jaws are used to complete the axial positioning of the semi-finished wheel hub. The radial positioning of the semi-finished wheel hub is completed by the cooperation of the tapered mandrel and the precision milled cap groove. After positioning, the inner rim, the back of the spokes, and the center hole position are finished to the finished product line.
105. Precision machining of the outer rim and front of the hub: The inner rim side lip end face after the precision machining process in step 105 is brought into contact with the end face block of the fixture. The pressure claw is used to complete the axial positioning of the semi-finished hub. The radial positioning of the semi-finished hub is completed by the cooperation of the mandrel with the center hole after the previous precision machining. After positioning, the outer rim, front of the hub and the position of the cap groove are precision machined.
106. Drilling bolt holes and valve holes: When axially positioning the semi-finished wheel hub, the same method as in 105 is adopted. The circumferential positioning of the semi-finished wheel hub is completed by using the positioning rod and window cooperation or by using image recognition. After positioning, the valve holes and bolt holes are machined to complete the machining of the wheel hub and obtain the finished wheel hub.
2. The machining process for forged passenger vehicle wheel hubs as described in claim 1, characterized in that, During the rough turning processes in 101 and 102, machining allowance is reserved for the finish turning processes in 104 and 105, taking into account the window shape and deformation size parameters.
3. The machining process for forged passenger vehicle wheel hubs as described in claim 1, characterized in that, When performing the rough milling process in step 103, the amount of deformation after the stress of the wheel hub is released during the rough milling process is taken into account to reserve machining allowance for the finish milling process in step 103.