What are the types of fixtures in CNC fixture machining?
by：QY Precision 2020-04-13
In CNC fixture machining, the fixture is a process device used to quickly tighten the workpiece during machining to keep the machine tool, tool and workpiece in the correct relative position.
That is to say, the working fixture is an indispensable part of machining, driven by the development of machine tool technology in the direction of high speed, high efficiency, precision, compounding, intelligence and environmental protection, fixture technology is developing towards high precision, high efficiency, module, combination, general purpose and economy. Fixture is also called fixture.
Broadly speaking, any device used to install workpieces quickly, conveniently and safely in any process in the process can be called a fixture.
For example, welding fixtures, inspection fixtures, assembly fixtures, machine tool fixtures, etc.
Among them, machine tool fixtures are the most common, often referred to as fixtures.
So what are the types of fixtures we use for CNC machining?
The following is a detailed classification of fixtures by Shenzhen hardware processing manufacturers.
The first type: General CNC machining fixture general CNC machining fixture refers to a fixture that has been standardized and can be used to process different workpieces within a certain range.
For example, a three-jaw chuck and a four-jaw chuck, a tip and a chicken chuck on a lathe;
Flat pliers, indexing heads and rotary worktables on milling machines.
They have great versatility and can be used to clamp different workpieces without adjustment or slight adjustment. This type of fixture has generally been standardized.
It is produced by a professional factory and supplied to users as machine tool accessories.
The second type: special CNC machining fixture refers to a fixture specially designed for the machining of a certain process of a certain work piece, with compact structure, quick and convenient operation.
Special fixtures are usually designed and manufactured by the user according to the requirements, and are suitable for production with fixed products and large batches.
The third type: combined CNC machining fixture is based on the standardization of machine tool fixture parts, and is pre-manufactured by a set of pre-manufactured, standard components and components with various shapes and sizes are assembled into various special fixtures according to the principle of combination according to the processing requirements of workpieces.
After the fixture is used, it can be disassembled and left for use when assembling a new fixture.
The application range of combined CNC machining fixture is very wide.
It is most suitable for many varieties, fast product changes, new product trial production and single-piece small batch production. In mass production, combined fixtures can also be used instead of temporary shortage of special fixtures to meet production requirements.
The combined fixture components can be assembled into various machine tool fixtures.
The emergence of CNC machine tools and flexible manufacturing units has further promoted the advancement of combined fixture technology and expanded the application range of combined fixtures.
The combined CNC machining fixture has the following characteristics: the combined CNC machining fixture component can be used multiple times, but once it is assembled into a fixture, the fixture structure is still specific and can only be used once.
When changing the processing object, it is generally necessary to disassemble it and reassemble it into a new fixture structure to meet the processing requirements of the new workpiece.
Unlike the special CNC machining fixture, the final accuracy of the combined CNC machining fixture is guaranteed by the accuracy of each component and direct combination, and no supplementary machining is allowed, otherwise, the interchangeability of components cannot be guaranteed.
Since the combination fixture is combined by various standard components, the rigidity is poor, especially the contact stiffness of the joint surface of the component connection, which has a great influence on the machining accuracy.
Generally, the overall size of the combined fixture is larger and less compact than that of the special fixture.
This fixture is not limited by the type of production and can be assembled at any time in response to the urgency of production.
The fourth type: assembled CNC machining fixture assembling CNC machining fixture refers to the standardized and serialized fixture components according to the processing requirements of a certain process of a certain work piece, directly according to the assembly method of special CNC machining fixture (Pin positioning, Bolt fastening)Special CNC machining fixture assembled.
The assembly fixture greatly shortens the design and manufacturing cycle of the special fixture, and most of the components of the original fixture can still be removed and reused when the product is modified, which is suitable for multi-variety and small-batch production.
The fifth type: Universal adjustable CNC machining fixture universal adjustable CNC machining fixture refers to a special fixture formed by adjusting or replacing individual positioning elements or clamping elements according to different sizes or types of workpieces.
The processing object is not very certain, the general scope is large, and it is suitable for multi-variety and small batch production.
The sixth type: group CNC machining fixture refers to an adjustable fixture designed for machining a group of parts in the group process.
The processing object is clear and can be used only by adjusting or replacing individual positioning elements or clamping elements. The adjustment range is limited to the workpiece of this part Group and is suitable for group processing.