Definition of fixture
A mechanical machining jig is a type of technological equipment that determines the exact position of the work piece relative to the cutting tool, and maintains that position during the machining process.
Uses of machining jigs
In general, machining jigs have the following main uses:
Ensure the position accuracy of the machined surfaces. Thanks to the jigs for fixing the part, it is possible to determine the relative position of the work piece with respect to the machine and the cutter precisely, and, moreover, a relatively high accuracy of this position can be achieved within a short period of time. stable, reliable and fast way.
Improve labor productivity. After using the jig it is possible to eliminate the marking and tooling step, thus significantly reducing the auxiliary time; In addition, using jigs to place parts can easily clamp many parts at the same time, process many positions, making the basic time coincide with the dependent time; When using mechanized jigs, a high degree of automation can take another step to reduce dependency time and increase labor productivity.
Expand the use range of machine tools. On metal cutting machines using specialized jigs can expand the technological capabilities of the machine. For example, on a lathe using a special jig, it is possible to turn multi-sided shapes.
Does not require high skill of workers and reduces their labor intensity.
Classification of machining jigs on metal cutting machines
Currently, machining jigs used in mechanical production are very rich, can be classified according to different characteristics, specifically:
Based on the scope of use
1. Universal jigs: are standard jigs that can be processed into different parts without the need for special adjustments. Universal jigs are widely used in small series production – single unit.
For example: 3-spoke chuck, 4-spoke chuck, vise, universal grading head, magnetic table, etc.
2. Specialized jigs: is a type of jig designed and manufactured for a certain processing operation of a part. Therefore, when the product changes or the operation contents change, the fixture cannot be reused. Therefore, this type of fixture is used when the product and technology are relatively stable in large, mass production.
For example: piston hole machining jigs, cam profile milling jigs, etc.
3. Universal mounting jigs (combined jigs)
According to the machining requirements of a certain operation, select a set of standard parts or pre-prepared parts to assemble into jigs. This type of fixture after use can be removed, cleaned and stored in storage for continued use.
Advantages: Using this type of fixture has the advantage of reducing the design and manufacturing cycle of the fixture, reducing the production preparation time; at the same time with a set of standardized jigsaw details that can be used many times, saving jigsaw materials; reduce labor and reduce product cost.
Disadvantage: It requires a large capital investment to manufacture standard details with high precision and gloss, the materials of these details are usually alloy steel, chrome steel, nickel steel; less rigidity than common jigs; heavier and bulkier than universal jigs.
Application: This type of jigsaw is suitable for small series production, a wide range of details, especially for new products.
Based on the machine used:
Turning jigs, milling jigs, drilling jigs, grinding jigs, etc.
Based on the energy source to clamp:
Manual clamp, pneumatic clamp, press oil, combination of compressed air - press oil, electromagnetic, vacuum
Based on the number of parts at the same time processing
Clamping one or more parts at once
