SU916152A1 - Broaching machine tool - Google Patents

Description

The invention relates to meta-image processing and can be used in the processing of parts by pulling.

A broaching block is known, the cutting teeth of which are divided into preliminary, rough and finishing parts and mouths — * but with a different inclination of the cutting edges of each part relative to each other [1].

However, with such a design, when machining parts with low rigidity, the cutting of a cutting vortex due to the placement of cutting blades along the machining contour of the parts does not always ensure high quality machining. ₍ $

The purpose of the invention is to improve the quality of processing.

The set chain is achieved by the fact that the teeth of the preliminary and finishing parts are made with negative rake angles, and the teeth of the rough part with positive rake angles, while the angle of inclination of the cutting edges is purely 2

Howling part exceeds the angle of inclination of the preliminary and draft parts in 2-5 times.

FIG. 1 shows a broaching unit; general form; in fig. 2 - the same, right view.

The broaching block contains a preliminary part 1, the teeth of which are made with a negative rake angle and inclination angle of the cutting edge λ _and , the teeth of the preliminary part 1 are made according to the profile cutting scheme. In the draft part 2 of the broaching block, the teeth are made with a positive rake angle and the inclination angle of the cutting edges \ ^. In the finishing part, the 3 teeth are made with negative rake angle and angle

inclination of cutting edges exceeding the angles λ _l and Ιιχ 2-5 times.

Pulling the unit works as follows.

The preliminary part 1 of the broach, intended for cutting the cortical layer of an allowance of non-constant in width and length and for cutting off non-metallic inclusions, is made with negative

3 916152 4

front corners, provides the cutting force, approaching the nominal pull force of the machine, and its uniform operation. The draft part 2, intended for cutting off the stock of a constant 5th across the width and length of the workpiece, already works with positive rake angles. The cutting force is reduced by cutting with teeth with positive rake angles, and the uniformity and approximation to the nominal pulling force of the machine is achieved by cutting off a constant allowance. The tendency to increase the cutting force when cutting an increased allowance can be changed by 15 positive front angles, which provide a reduction in the cutting point. Thus, the pulling vulture, when passing the roughing part 2 of the pulling, approaches the pulling vortex of the preliminary part 1. The cutting proceeds smoothly.

Finishing part 3, designed to cut the finishing thin metal layer, contributes to a sharp drop in cutting force. Therefore, when assigning the front corner angles and tilt angles Ι3 exceeding the slope angles <

X _and and λΐ} ⁱⁿ 2-5 times, cutting vulture increases, approaching the nominal tractive force of the machine. Thus, 30 due to the distribution of the angular parameters of the teeth over the length of the draw block, a smooth change in the cutting force over the entire length of the working stroke of the machine is ensured. The deformation of the workpiece is reduced, the quality of the surface being treated increases.

Technical and economic efficiency in the application of the invention due to the improved quality of processing.

Claims (1)

Claim A broaching unit, the cutting teeth of which are divided into preliminary, rough and finishing parts and installed with different inclination of the cutting edges of each part relative to each other, characterized in that, in order to improve the quality of processing, the teeth of the preliminary and finishing parts are made with negative front corners, and the teeth of the rough part - with positive front angles, while the angle of inclination of the cutting edges of the finishing part exceeds the angle of inclination of the preliminary and draft parts by 2-5 times,