CN2197192Y

CN2197192Y - Centering drill bit

Info

Publication number: CN2197192Y
Application number: CN 94215595
Authority: CN
Inventors: 杜伯民
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-07-05
Filing date: 1994-07-05
Publication date: 1995-05-17
Anticipated expiration: 2004-07-05

Abstract

The utility model belongs to the electric tool field and is created for overcoming the problem that a material partially returnable drill can not be automatically centered. As is disclosed by the attached figure, the drilling process on pre-trepanning of the utility model is constrained by a pilot drill body (3), resulting in accurate positions. Apparently, when used for drilling holes, the material partially returnable drill can be directly inserted into a wall along the drilled holes of the pre-trepanning. Thus, the material partially returnable drill can be automatically centered according to the drilling trace of the pre-trepanning and then successfully carry out trepanning and drilling actions.

Description

Centering drill bit

The utility model belongs to field of power tools, and it is that treapanning drill can not the self-centering innovation and creation in order to overcome in practice.

In pipeline is installed, often run into and drill the hole that wall is entered the room.Usually, run into the hole of Φ 40mm, generally all hole with treapanning drill, this be because, treapanning drill is in when boring, around the cutting hole, and the center material in hole is not cut, so center material generally all is the material core by complete taking-up.So the cover drill bit is compared with common drill bit, and is not only laborsaving, and the efficient height.But because its cutting edge all is distributed in border, tubular drill body top, so cause its boring initial, the operator is difficult to control electric tool---the self-centering boring of electric hammer or feedwater electric drill, so tend to occur treapanning drill about the surface of wall of level and smooth polishing, about rolling back and forth.This not only can scratch large-area surperficial body of wall, and makes boring be difficult to normally carry out.Obviously, this not only influences penetration rate, but also brings the rehabilitation problem after a series of borings.

The utility model solve the initial treapanning drill of jacking can not the practice of self-centering boring in innovation and creation.

Further specify concrete structure of the present utility model and enforcement below in conjunction with accompanying drawing:

2. 1. the utility model can reach the centering drill body with tubular jacking drill body by petioliform or storehouse shape drillstock and 3. constitute.See accompanying drawing:

1. drillstock is made with reference to the treapanning drill drillstock, can make an electric tool together with treapanning drill like this.

Tubular jacking drill body 2., external diameter in it, edge geometrical shape all should make with reference to the treapanning drill parameter, but its internal diameter should be smaller, external diameter should be bigger, recognizes brill when helping like this changing treapanning drill boring.The cutting edge of tubular jacking drill body, the carbide alloy of employing brazing right quantity, its cutting edge protrudes should be suitable.Tubular jacking drill body 2. with drillstock 1., both can be made into one, also can adopt to be threaded, also can be assembled into one by modes such as tapering self-lockings.But after the assembling, enough cutting depth should be arranged, thereby enough pre-jacking degree of depth are arranged, make treapanning drill along feel relieved the smoothly jacking boring of pre-jacking track.

3. the centering drill body is similar to drill hammer, both can 1. make one to it and drillstock, adds weldering carbide alloy cutting edge, also can utilize the commodity drill hammer, utilizes methods such as the jackscrew top is solid to make itself and drillstock 1. be assembled into one.But the diameter of centering drill body should be able to satisfy the requirement of centering stress, and assembling back cutting edge, should suitably be higher than tubular jacking cutting edge, thereby guarantee firmly to feel relieved performance.

The utility model is by accompanying drawing as can be known: its boring, at first be 3. in predetermined accurate bore position self-centering boring by the centering drill body, when 3. the centering drill body holes when reaching certain depth, tubular jacking drill body 2., just under the constraint of centering drill body, naturally begin the boring of pre-jacking,, can not occur about the treapanning drill for this reason, about the phenomenon of rolling back and forth.Obviously, when pre-jacking boring reaches certain depth, change treapanning drill again and carry out jacking boring, treapanning drill just can directly insert pre-jacking boring undoubtedly, and according to the accurate position of pre-jacking, along the Cutting trajectory of pre-jacking, and self-centering boring under the constraint in its pre-jacking hole.

Claims

1, a kind of jacking pilot bit that is used for, comprise it is characterized in that described jacking pilot bit have drillstock 1., tubular jacking drill body 2., centering drill body 3..

2, jacking pilot bit according to claim 1, it is characterized in that described drillstock 1. the jacking drill body drill body of 2. feeling relieved 3. be combined into one.

3, jacking pilot bit according to claim 1 and 2,1. the jacking drill body drill body of 2. feeling relieved was both coaxial to it is characterized in that described drillstock, and centering drill body cutting edge is higher than tubular jacking drill body cutting edge.