Jigs and machining fixtures

Jigsaws and fixtures are very similar in performance, the difference between the two is in how the tool is directed towards the workpiece. In terms of components used, such as position pins and positioning components, jigs and fixtures are similar. It can be said that the main difference between the two is in their crime and volume. Due to the fact that more forces are applied to the fixtures during the production operation, it has a stronger and larger building than the similar Jig.

A jig is a special holding device in which a workpiece is held or placed to be machined. In addition to the workpiece, Jig drives machine tools accurately, quickly and safely. Jigs usually have hardened steel guide bushes and are used for drilling, brazing, bracing and similar processes.

A fixture or strap is a holding device on which only the workpiece is fastened to perform machining operations. Using the fixture, the position of the cutting tool relative to the workpiece can be adjusted using a filler or adjusting device. The fixture must be firmly attached to the production machine. Fixers are tools for positioning and storing parts when cutting on lathes, milling machines, lathes, stones and saws, and are also used during welding and assembly. There are no tool guides in the fixtures and the chip removal tool is in direct contact with the workpiece.

There are many rules to follow when designing jigsaws and fixtures:
The structure and the main frame of the restraint must be strong enough so that the forces resulting from the machining do not cause deviation and complexity in them and vibration does not occur during the chip removal.

The frame may be made of various parts, which are joined together by welding or by bolts.

When removing and closing the workpiece, all machine movements are regular and in the shortest possible time.

All clamps, position pins, and positioners are visible and available to the machinist for cleaning, positioning, or tightening.

In the design of the clamp, the exit of the chips should be considered so that the chips can be easily removed and not stored inside the clamp, because the presence of the chip is effective at the time of positioning.

Restraints have the ability to position parts within the allowable tolerance.

Replacing the workpiece inside the clamp is easy and the workpiece is in the correct position.

Observe all safety principles to protect the machinist.

Restraint points:
fixture

1- Productivity

Eliminates restraint, marking, deployment, and repeated control. This feature reduces working time and increases productivity.

2- Ability to replace and replace

The constraint creates the same quality in the product. Each of the parts is correctly in its own set and all similar parts can be replaced.

3- Cost reduction

More production, reduced waste, easier alignment and savings in labor costs will significantly reduce the cost of goods.

4- Reducing the need for worker skills

Ease of closing and closing the workpiece makes it easier. The guiding elements of our tools remind us of their proper placement relative to the workpiece. Replacing a skilled worker with an unskilled worker will save labor costs.

Types of jigs
Jigsaws are divided into two main categories:

Jigsaw piercings

Perforated jigs

Drilling rigs are used when large holes or standard diameter holes need to be machined.

Drilling jigs are used in processes such as drilling, electro-screwing, tooling, bending, and angle drilling.

Types of fixtures
The types of fixtures are determined based on the method of their construction. Common types of fixtures include: plate fixtures, angular fixtures, rotary fixtures, multi-station fixtures, and clamps.

Screen fixtures are the simplest type of fixture. The main part of this fixture is a base plate on which various parts such as mounting pins and holders are installed.

Vertical angle fixture is a modified version of the plate fixture. Using this tool, the workpiece can be machined on surfaces perpendicular to its surface. Of course, this fixture can be designed in such a way that the parts can be machined at any desired angle.

Rotary fixtures are used when machining positions need to be placed on the workpiece at regular intervals around it.

Multi-station fixtures are used when a high production number and production speed are required and the machining cycle is continuous.

Clamps are the most common type of fixture. Clamps are actually a simple fixture to hold the parts. By modifying the shape of the clamp jaws, it can be used to hold parts with different shapes.

Clamp-mountable fixtures These types of plate fixtures are usually small, simple and lightweight. Instead of being mounted directly on the machine, these fixtures are mounted on clamps or three machine systems. Small parts that require little machining are usually fastened to these fixtures. The plate fixtures and the fixtures that are mounted on the clamp are similar in appearance. It can be said that the only difference is that larger parts can be placed and machined on the plate jigs.

Source: https://farco-psr.com/what-is-a-fixture-and-what-are-its-types/

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