Broaching Fixtures

Broaching Fixtures

Broaching Fixtures - Introduction

As in other machining operations, fixturing of the workpiece is required in broaching too. Fixtures generally are justified for holding workpieces being broached where the production is large.

Tremendous cost saving can be obtained by using a fixture that reduces the work handling time and labor.

Functions of

Broaching fixtures perform several functions such as:

(i) They must locate the workpiece accurately and hold it securely.

(ii) As in broaching helical gears, the fixture besides positioning the part accurately and firmly, should also permit the part to rotate as required.

(iii) Fixtures may be used to carry workpieces in and out of the broaching position, or to carry them from one broaching position to another where more than one broach is required (as in broaching the propeller blade hub).

(iv)Fixtures may also be used to guide the broach when it moves over or through the workpiece.

Types of

Broaching fixtures may be manual, semiautomatic or automatic

Cost considerations and the quantity of parts to be broached will largely determine the type of fixture used. Semi automatic or automatic fixtures may be operated pneumatically, hydraulically or mechanically.

Broaching fixtures are simple in comparison with those of other processes, one may even be just a plate to bear the put and with a hole to pass the broach. Another simple fixture/known as work horn is a special type of faceplate used when broaching keyways.

A ground diameter ort the back of the horn fits snugly into the machine platen or into a reducing bushing. A round pilot on the opposite end accurately positions the work. The horn is slotted to provide a guide for the broach. AU faces of the horn are accurately produced to hold the workpiece square and parallel, to the axis of broach travel.

The force that is applied to the workpiece by the broach as it is being pulled through the cut holds the workpiece firmly in the fixture. In order to bear these large forces, the fixture must be strong.