Overview of standardization of tooling fixture design
1.The basic methods and steps of tooling fixture design
Pre-design preparation of the original data for the design of tooling fixtures include the following.
a) design notice, finished part diagram, blank diagram and process route and other technical information, to understand the processing technology requirements of each process, positioning and clamping scheme, the processing content of the previous process, the blank situation, the machine tools, tools, inspection gauges used in processing, machining allowance and cutting amount, etc..
b) to understand the production batch and the need for fixtures.
c) to understand the main technical parameters, performance, specifications, accuracy of the machine tool used and the connection size of the structure of the part connected with the fixture, etc.
d) the standard material stock of jigs.
2.Problems to consider in the design of tooling fixture
Fixture design generally has a single structure, giving the impression that the structure is not very complex, especially now that the hydraulic fixture has become popular, so that its original mechanical structure is greatly simplified, but if the design process is not considered in detail, unnecessary trouble is bound to occur: a) the gross material of the machined part, the size of the jig, and the size of the connection with the machine tool; b) the size of the jig.
a) The blank allowance of the machined part. Causes the blank size is too large and produces interference. So be sure to prepare a blank drawing before designing. Leave enough space.
b) The chip evacuation smoothness of the fixture. Design due to the limited processing space of the machine tool, fixtures are often designed to be more compact space, which often ignored in the machining process generated by the chip in the fixture dead-end storage, including the chip liquid outflow is not smooth, to bring a lot of trouble later processing. So at the beginning of the actual process should consider the problems that arise in the process of processing, after all, the fixture is to improve efficiency and facilitate operation.
c) The overall openness of the fixture. Neglecting the openness will cause the operator to have difficulty in loading the card, which is time-consuming and laborious.
d) The basic theoretical principle of fixture design. Every fixture has to go through countless clamping and unclamping actions, so it may be able to meet the user’s requirements at the beginning, but the fixture should have its accuracy retention, so don’t design something that goes against the principle. Even if you can get away with it at the moment, it will not be sustainable for a long time. A good design should be able to withstand the hammering of time.
e) Replaceability of positioning elements. Positioning elements wear heavily, so quick and easy replacement should be considered. It is best not to design for larger parts.
The accumulation of experience in fixture design is very important, sometimes the design is one thing, in the actual application is another thing, so a good design is a continuous process of accumulation and summary.