The quality and cost of machining have a great influence on the quality and cost of machine parts and even the whole machine. Therefore, in the design process, need to consider the mechanical processing technology.
Especially for some special mechanical parts, its manufacturing process is often very special, in the design should pay special attention to consider. Whether a part can be manufactured or not can be a decisive factor in the adoption of a design. Therefore, for the structural design of these machined parts, the following problems need to be paid attention to.
1, save material parts structure design
Pay attention to reduce the blank size, convex reason is directly made of round steel, such as the design of the maximum diameter of 100mm, to use 105mm or 110mm round steel processing. If the design maximum diameter 98mm, you can use 100mm steel processing, can save a lot of steel.
2, reduce the mechanical processing workload structure design
(1) The influence of casting error should be taken into account
The error of casting parts is relatively large, in the design of casting machining surface need to be fully considered. If the bearing end cover matches the boss on the box body, but the position of the boss on the box body is difficult to be very accurate. If the flange of the end cap is designed to be exactly equal to the diameter of the boss, the end cap will often protrude beyond the boss due to the influence of the casting error. So the boss diameter of the casting should be larger.
(2) Surfaces with different machining accuracy should be separated
When two surface roughness requirements are different, there should be a clear dividing line between two surfaces. This is not only convenient processing, but also beautiful shape.
3. Reduce the structural design of manual processing or supplementary processing
(1) Surface grinding instead of manual grinding guide
The guide rail of the large optical measuring instrument universal tool microscope was originally designed as a circular guide rail, which is used for manual grinding, and then modified as a flat V guide rail, which is processed by the surface grinder, and the productivity is greatly improved.
(2) Use plane grinding or fine planing instead of scraping the dividing surface of the reducer
Split type reducer box box surface, the requirement of higher flatness, the original some production units with manual scraping, workload, low productivity, later more than surface grinding machine processing fine planer.
4. Simplify the shape and requirements of the processed surface
(1) It is necessary to avoid the stop match of non-circular parts
A flange is fitted to the surface of the box part. In order to make the cover with accurate positioning, in addition to fixing with screws, the design of a stop, the matching hole should be circular, not rectangular, square, oval and other shapes.
(2) must be full of complex shape parts chamfering
The chamfering of complex shape parts is difficult to process. Such as oval and other complex shapes, it is difficult to use mechanical method chamfering, with manual method chamfering, it is difficult to ensure the quality of processing.
5, easy to clamp, measurement parts structure design
Avoid clamping parts structure, mechanical parts in processing need to be clamped on the machine tool, so mechanical parts need to be easy to clamp. In addition, the clamping part should have a large enough supporting force to ensure that under the cutting force, the part will not shake. Therefore, the parts have enough stiffness to avoid clamping deformation.
6, avoid cutting tools in unfavorable conditions
The tool is easy to enter or exit the processing surface, the tool into or out of the processing surface, are required to have a certain movement space, the design should retain enough clearance.
7. Correctly handle the structure of shaft and hole (inner and outer surface)
Complex machining surface to design the outer surface rather than the inner surface, shaft parts than hole processing is easy. So when you have two shaft, hole shaped parts together, and they have some complex structure between them, it’s often better to design the structure on the shaft than on the inside surface of the hole.