1、 Process analysis of forging aluminum alloy wheel hub 8 E 2 y) Q, O; y- C' J
The machining accuracy of parts in Guangdong machining plant depends on the process system composed of machine tool, fixture, cutter and workpiece. In the process of machining, cutting force, clamping force, gravity, inertia force and transmission force will cause the deformation of the process system; At the same time, the change of the position of the force point of the cutting force, the change of the blank machining allowance and the change of the material hardness will cause the change of the deformation of the process system. The deformation and change of the process system will produce the workpiece error. The deformation caused by the change of cutting force and cutting force can be minimized by reasonably selecting the cutting parameters and tool geometric parameters. In order to reduce the error and deformation as much as possible, the machining allowance should be reasonably allocated, and the machining should be carried out in multiple processes to minimize the deformation of the parts. H! o6 M5 k. C4 t {* u: k!  k;  In view of these errors, effective measures should be taken. 5 D5 E.D: J% S
2、 Processing technology of aluminum alloy wheel hub
According to the process analysis of the parts, Guangdong Machinery Works has implemented the measures of how to control the deformation of the parts and ensure the accuracy requirements one by one in the process specification and actual operation. " c' u7 `3 u' e
1. The selection of processing benchmark! w;  w1 x/ ? 4 E
The selection of rough datum: firstly, the design datum is considered as the process datum to avoid the error caused by the non coincidence of datum; At the same time, try to choose smooth, flat, large area surface as the datum. The flash, burr and residual raised part of pouring riser on the datum plane should be removed to ensure accurate positioning and reliable clamping. In the process of hub, we select the largest outer edge as the rough machining benchmark. The precise datum should be consistent with the design datum, assembly datum and measurement datum as far as possible. And the stability, positioning accuracy and tightness reliability of machined parts should be fully considered. In finish machining, the inner hole and end face are selected as finish datum.
2. Rough machining 3 y m #} 2 A: F 'y
Guangdong Machinery processing factory should fully consider the above situation in the process of processing. Roughing machine tool, fixture selection requirements are not high, can meet the rough machining accuracy. In order to process aluminum alloy parts with high precision in dimension accuracy and surface roughness, the machining allowance for each machining surface should be considered first, especially for parts with complex shape, high precision and large quantity, which results in large amount of cutting during rough machining. This is 9 ~ 2 y D1 I6 D / R - M: Z caused by thermal deformation and chip accumulation
Therefore, it is necessary to increase the working procedure, reasonably select the geometric parameters of cutting tools, the number of machine revolutions and cutting parameters.
3. Semi finishing. ^ a) W "M0 w9? 3 X, _
Semi finish machining is to improve the processing efficiency, solve the problem of aluminum alloy stress deformation and cutting thermal deformation in the process of processing, and extend the cooling time. Properly increase the number of revolutions, cut in 2-3 times, reduce the repeated friction of the surface of the workpiece as far as possible, and the cooling time is 24h. In semi finish machining, because the feed rate is small, it will not produce large stress. At the same time, the ellipse produced in rough machining can be removed and a small margin is left for finish machining. 4 ~5 B* D) I6 t7 v
4. Finish machining # ^ 7 h / N # L / R + [* W1]_ 9 w
In order to ensure the finished product size and surface roughness of aluminum alloy parts, combined with the characteristics of aluminum alloy materials, in the finishing process, due to the small margin left, we adopt a higher number of revolutions and a smaller tool amount. It is very effective to use larger back angle in tool grinding/ C" X) S  j/ ]- c6 R1 s
3、 Effect
There are many factors that affect the accuracy of parts. Considering from many aspects, we should reduce the influence of many factors to the minimum and arrange the process reasonably to ensure the accuracy of parts. Through the actual processing verification, it meets the design requirements, and the quality is stable and the effect is good.