Fixture design is generally in the parts of the mechanical processing process according to the specific requirements of a process. The possibility of fixture realization should be fully considered in the process formulation, and modification Suggestions on the process can be put forward if necessary in the design of the fixture. The design quality of jigs and fixtures should be able to ensure the stability of the processing quality of the workpiece, high production efficiency, low cost, convenient chip discharge, safe operation, labor-saving and easy manufacturing, maintenance, and other indicators for its measurement.
1. Basic principles of fixture design
(1) Meet the stability and reliability of workpiece positioning during use;
(2) Enough load or clamping force to ensure that the workpiece is processed on the fixture;
(3) Simple and fast operation in the clamping process;
(4) The fragile part must be a structure that can be replaced quickly, and it is better not to use other tools when conditions are sufficient;
(5) Meet the reliability of repeated positioning of the fixture in the adjustment or replacement process;
(6) Avoid complex structure and high cost as much as possible;
(7) Choose standard parts as constituent parts as possible;
(8) To systematize and standardize the company's internal products.
2. Basic knowledge of fixture design
A good fixture must meet the following basic requirements:
(1) To ensure the processing accuracy of the workpiece, the key to ensure the processing accuracy, first of all, is to correctly select the positioning reference, positioning method and positioning element, positioning error analysis should be carried out when necessary, but also pay attention to the impact of the structure of other parts in the fixture on the processing accuracy, to ensure that the fixture can meet the machining accuracy requirements of the workpiece.
(2) The complexity of special fixtures to improve production efficiency should adapt to the capacity, should try to use a variety of fast and efficient clamping mechanisms, to ensure convenient operation, shorten the auxiliary time, improve production efficiency.
(3) The structure of the special fixture with good process performance should be simple and reasonable, easy to manufacture, assembly, adjustment, inspection, maintenance, etc.
(4) Good performance fixture should have sufficient strength and stiffness, the operation should be simple, labor-saving, safe, and reliable. Under the premise of objective conditions and economical application, pneumatic, hydraulic, and other mechanical clamping devices should be used as far as possible to reduce the labor intensity of operators. The jig should also be convenient for chip removal. If necessary, a chip removal structure can be set to prevent the chip from destroying the positioning of the workpiece and damaging the tool, and prevent chip accumulation from bringing a lot of heat and causing process system deformation.
(5) The special fixture with good economy should adopt standard components and standard structure as far as possible, and strive to be simple in structure and easy in manufacturing, so as to reduce the manufacturing cost of the fixture. Therefore, the design should be based on the order and capacity of the fixture program for necessary technical and economic analysis, in order to improve the fixture in the production of economic benefits.