Adjustable fixture

Adjustable fixture can be divided into general adjustable fixture and group fixture (also known as special adjustable fixture). Their common feature is that as long as individual positioning, clamping or guiding elements are replaced or adjusted, they can be used for the processing of multiple parts, so that the single small batch production of multiple parts can be changed into the “batch production” of a group of parts on the same fixture. After product renewal, as long as the parts belong to the same type, they can still be processed on this fixture. Because adjustable fixture has strong adaptability and good inheritance, the use of adjustable fixture can greatly reduce the number of special fixture, shorten the production preparation cycle and reduce the cost.

Combined fixture

Modular fixture is also known as “modular fixture”. It consists of a series of machine tool fixture elements with standardized design, different functions and different sizes. Customers can quickly assemble various types of machine tool fixtures according to processing requirements, like “building blocks”. Because the combined fixture saves the time of designing and manufacturing special fixture, greatly shortens the production preparation time, thus effectively shortens the small batch production cycle, that is to say, improves the production efficiency. In addition, the combined fixture also has the advantages of high positioning accuracy, large clamping flexibility, recycling and reuse, energy-saving and material saving manufacturing, and low use cost. Therefore, in small batch processing, especially when the product shape is complex, the use of combined fixture can be preferred.

Precision combination flat pliers

In fact, precision combined flat pliers belong to the “assembly” in the combined fixture. Compared with other combined fixture elements, they are more universal, more standardized, easier to use and more reliable in clamping, so they are widely used in the world. Precision combination flat pliers have the advantages of fast installation (disassembly), fast clamping, etc., so it can shorten the production preparation time and improve the efficiency of small batch production. At present, the clamping range of precision combination flat pliers commonly used in the world is generally within 1000mm, and the clamping force is generally within 5000kgf.

It should be noted that the precision combined flat pliers mentioned here are not old machine vises. The old machine vises have single function, low manufacturing accuracy, can not be used in groups, short service life, and are not suitable for use on CNC machine tools and machining centers.　

It should be noted that the precision combined flat pliers mentioned here are not old machine vises. The old machine vises have single function, low manufacturing accuracy, can not be used in groups, short service life, and are not suitable for use on CNC machine tools and machining centers.　

Electric permanent magnet clamp

The electric permanent magnet clamp is a new type of clamp designed by using the modern magnetic circuit principle and taking the neodymium iron boron and other new permanent magnetic materials as the magnetic source. A large number of machining practices show that the electric permanent magnet fixture can greatly improve the comprehensive machining efficiency of CNC machine tools and machining centers.

The clamping and unclamping process of the electric permanent magnet fixture only takes about one second, so the clamping time is greatly shortened; the positioning elements and clamping elements of the conventional CNC machine tool fixture occupy a large space, while the electric permanent magnet fixture does not have these elements occupying space, so compared with the conventional CNC machine tool fixture, the clamping range of the electric permanent magnet fixture is larger, which is conducive to making full use of the work of the CNC machine tool Table and machining stroke are beneficial to improve the comprehensive machining efficiency of CNC machine tools. Generally, the suction of the electric permanent magnet clamp is 147 ~ 176.4n/cm2, so it is necessary to ensure that the suction (clamping force) is sufficient to resist the cutting force. Generally, the adsorption area shall not be less than 30cm2, that is, the clamping force shall not be less than 4.41kn.

In modern automatic production, the application of numerical control machine tool has been more and more extensive. In CNC machining, the movement of tool or worktable is controlled by program according to certain coordinate position.　

The following points should be paid attention to when designing the fixture of numerical control machine tool:

1. The origin (tool setting point) shall be set on the fixture of numerical control machine tool.

2. There is no need to set tool guide device for numerical control machine tool fixture. This is because the CNC machine tool, fixture, tool and workpiece always maintain a strict coordinate relationship, and there is no need for guiding elements to determine the position between the tool and workpiece.

3. NC machine tools often need to process workpiece in several directions, so the fixture of NC machine tools should be open type.

4. Adjustable fixture, assembly fixture and combination fixture shall be selected as much as possible on CNC machine tools. Because the workpieces processed on CNC machine tools are usually produced in small batches, it is necessary to use flexible clamps with short preparation time.

5. The clamping of numerical control machine tool fixture shall be firm and reliable, and easy to operate. The position of the clamping element shall be fixed to prevent the element from colliding with the tool during automatic machining.