CN88203889U - Step type twist drill - Google Patents

Abstract

The utility model relates to a step type twist drill, the drills of the step type twist drill are made into a step type, with a same shape and different diameters. The utility model has the advantage of high precision of machined workpieces, and is widely applied for machining concentric holes with the different diameters.

Description

Step type twist drill

The utility model relates to a kind of improved spiral bit, is particularly suitable for processing with one heart and the shoulder hole of different-diameter.

Existing spiral bit, the bit body of its boring is identical with the diameter of drill bit.The hole that this drill bit processes is concentric hole with diameter.Need processing with one heart and during the shoulder hole of different-diameter, to use the bit bore of minor diameter earlier, after having bored the hole of minor diameter, boring reaming on the good aperture with large diameter drill bit again, expand to become with one heart and the shoulder hole of different-diameter, because of the head of large diameter drill bit has tapering, the ladder position of the shoulder hole that expands also has tapering, sometimes also to flatten the tapering part of ladder with forsner bit, with this spiral bit converted products:

1, operation is many, and efficient is low;

2, repeatedly processing, concentricity is poor, and precision is low, can not satisfy the needs of high accuracy product.

The purpose of this utility model is, but a kind of time processing moulding, precision height, stepped twist drill bit that efficient is high are provided.

The utility model is achieved in that

Spiral bit is made with one heart and the stepped twist drill bit of different-diameter, and greater than the diameter from one section near bit body of drill bit head, the head of drill bit is with identical from one section near diameter of drill bit head from the diameter of one section near bit body of the handle of drill bit.

Further specify technical characterictic of the present utility model below in conjunction with accompanying drawing:

Fig. 1, the stepped twist drill bit of tapering is arranged for the end difference bit strip;

Fig. 2, for the ladder position not with the stepped twist drill bit of tapering.

In Fig. 1, (1) is the handle of drill bit, (2) be the step portion of drill bit, (3) be the cutting edge of drill bit step portion (2), the angle α of the bit body (4) of cutting edge (3) and reduced diameter section is 135 °, the identical and diameter difference of the shape of the shape of step portion (2) and reduced diameter section bit body (4); The tapering of cutting edge (3) can make the end difference bit strip in the hole that processes that tapering is arranged.In Fig. 2, (5) be the handle of drill bit, (6) be the step portion of drill bit, (7) be the cutting edge of drill bit step portion (6), cutting edge (7) is 90 ° with the angle β of the bit body (8) of reduced diameter section, this kind removes the step portion of the shoulder hole that the ladder type spiral bit processes and is not with tapering, the identical and diameter difference of the shape of the shape of step portion (6) and the bit body (8) of reduced diameter section, and the bit body of reduced diameter section (4) reaches the shape that is shaped as existing spiral bit of (8).The utility model:

1, the moulding of once punching, speed is fast,

2, drilling precision height can guarantee product quality.

If need to beat the shoulder hole of multi-ladder, drill bit can be made the spiral bit of multi-step.

Claims (1)

1. A kind of stepped twist drill bit is characterized in that: the same diameter of bit body right and wrong that is used to hole stepped, the shape of this ladder be, from the diameter of one section near bit body of bit sub greater than diameter from bit sub one section bit body far away.

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