What is the difference between a universal fixture and a combined fixture?

Posted by sere on February 21st, 2020

Universal fixture:

Fixtures can be used for different workpieces.

Combination fixture:

1.Working principle and characteristics of combined fixture

Definition: It is a new type of process equipment developed on the basis of standardization of machine tool fixture parts. It is assembled from a set of universal components and assemblies whose structure, dimensions have been standardized, serialized and standardized.

It can be seen that the combined fixture is a special fixture that can be repeatedly used for parts and components. According to production practice, compared with the single-use special fixture, it uses combination instead of design and manufacturing, so it has the following characteristics:

1. Flexible and wide adaptable, which can greatly shorten the production preparation cycle.

2. It can save a lot of manpower and material resources and reduce the consumption of metal materials.

3. It can greatly reduce the area of ​​the warehouse where special fixtures are stored, simplifying management.

Disadvantages: large dimensions, bulky, and poor rigidity. In addition, due to the large reserve of required components, one-time investment costs are high.

2. Combination fixture system

According to the shape of the connecting base surface between the components during combination, the combined fixture can be divided into two systems: slot system and hole system.

1) The slot system combined fixture uses slots (T-slots, key slots) and keys to match to achieve positioning between components. Because the position of the component can be adjusted steplessly along the longitudinal direction of the slot, it is very flexible to assemble and has a wide range of applications. It is the earliest developed combination fixture system.

2) The main component surface of the hole system combined fixture is a coordinate hole system consisting of a cylindrical hole and a threaded hole. combination and fastening between components is achieved by positioning pins and bolts.

3. combination of combined fixtures

The combination of the combined fixture is a process of selecting the relevant components and assemblies to be assembled according to the processing requirements of the workpiece and according to a certain procedure, thereby obtaining the required fixture.