Broaching Hook is the name given to the tools that process simple or complex forms into the hole or on the surface of the part by means of suitable apparatus and machine systems, by moving in a single axis serially and precisely, by removing chips with their stepped teeth.
The brooch needle is specially designed for the work piece. Dimensional details of the workpiece, material type and hardness, heat treatment conditions are taken into consideration in the design of the brooch.
A typical pull-type round brooch has an anterior retainer region, a region of the incisors, and a posterior retainer region.
The front holder part is specially designed for each brooch needle in accordance with the holder head and the holder nail mechanism for the brooch drawing stand to catch the brooch. Bedding area is located just behind the front holder part. This region undertakes the task of axising the precision turned material to the broaching claw just before the broaching pin teeth start to cut. Before broaching, it is desired that the part hole fits snugly to this front shaft. The broach needle adapts to the axis of the part hole while creating a form by removing chips, and if the part hole is wider than necessary, the axis of the form to be formed may form a little off the desired axis. For this reason, precision turning of the hole before broaching is an important process.
The design of the area where the incisors are located is very critical and the design must be made by a specialist. Fast chip removal takes place in the roughing area, depending on the material type, broaching length and the form to be created, the loads and chip chamber values that will come to the tool should be calculated properly and the design should be made in accordance with this calculation.
Design elements include many parameters, each of the dimensions used in the determination of tooth form has a critical importance. Results such as rapid blunting, short tool life, breakage of teeth, breakage of the tool, increase in machine loads, and unwanted deformations on the part surface may occur in the wrongly designed broaching awls.
Before finishing, the teeth create the desired form in the part with high surface quality by cutting with low passes. Especially in internal gear forms, it is important to create precise tooth flank forms that assume function. The tooth flank forms will determine the quality, life and efficiency of the gear.
The final form is formed in the finishing area and the calibrated teeth in the last part ensure that the brooch crochet cuts in the desired form. It ensures that the final form after periodic grinding is not affected by these operations.
The rear holder area, on the other hand, is used to automatically catch heavy brooches by the bench holder mechanism and lift them into the air. If the brooch is placed and lifted by hand, the back holder part is not needed, but if the brooch is heavy or if multiple broaches are used at the same time, the brooch awls are manufactured with the rear holder zone to be used with the bench back holder system to save time.
The advantages of forming with the broaching technique, which is a machining method;
It is very fast compared to other techniques,
Providing high precision, continuously and stably,
It can provide high surface quality,
Its application is simple, effortless and efficient,
Long tool life; With a brooch set, up to 150,000 parts can be drawn by paying attention to the correct sharpening periods.
Areas where brooch crochets are mainly used;
automotive industry
aviation industry
Manufacture of hand tools
Rack manufacture