JPH10100135A - Drilling and hole expanding tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved tool so that operation is not obstructed by a cut powder and maintenance is made easy. SOLUTION: This tool has a cylindrical body 1 having a compression spring 5 arranged therein and having two guide pins 8, 9 provided thereto in opposed relationship, a rotary receiving plate 15 attached to the under surface of the cylindrical body 1, a drill shank 20 provided to the cylindrical body 1 so as to be movable against the compression spring 5, a guide bar 30 inserted into the cylindrical body 1 and having an opened long groove 31 provided to the leading end thereof and fixed to the drill shank 20 at its rear end part, and a drilling cutter 40 having a head part 41 protruded from the leading end of the guide bar 30 and supported within the long groove 31 in a revolvable manner by a shaft. A cutting blade chip 43 is screwed in a square recessed part 48 along the warped surface 42 of the head part 41, and the drilling cutter 40 is displaced toward the cutting blade chip 43 on its rear end side. Both sides thereof are set to the cam surfaces 44, 45 coming into contact with the guide pins 8, 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing an anchor such as an anchor bolt to a base such as concrete or bedrock by forming a conical expanding portion below a straight hole previously drilled by attaching to a hammer drill or the like. The invention relates to a drilling and spreading tool to be formed.

[0002]

2. Description of the Related Art As a drilling and expanding tool for forming a conical expanding portion below a straight hole previously drilled in a base, a drilling and expanding drill disclosed in JP-B-63-34005 is known. .

[0003] The conventional drilling and expanding tool shown in FIG. 6 has a compression spring 51 provided therein and a guide hole 59 provided with two guide pins 5.
A cylindrical body 50 provided with the cylinders 2 and 53 facing each other;
0, a drill shank 55 fitted and fitted with a flange portion 58 so as to be movable in the axis line against the compression spring 51;
A guide bar 60 fitted in the cylindrical body 50 and having a rear end 61 fixed by a pin 57 in a hole 56 of the drill shank 55; and a pivot pin fitted in a long groove 62 of the guide bar 60. The cutter blade 65 is rotatably supported on the guide bar 60 by the 63.

At the tip of the cutter blade 65, a tip 66 made of cemented carbide is brazed.
The rear end of the cutter blade 65 is displaced toward the tip 66 with respect to the axis of the guide bar 60, and both sides are substantially parallel cam surfaces 67 and 68.

The cam surface 67 on the tip 66 abuts on the tip of the guide pin 52, and the cam surface 68 on the other side abuts on the tip of the guide pin 53.
At the time of operation, the guide pins 52 and 53 regulate the lateral ejection amount and the retracting amount of the cutter blade 65.

Then, when using this, the guide bar 60 is inserted into a straight hole previously drilled in the base,
The lower surface 54 of the cylinder 50 is pressed against the base surface to lower the drill shank 55 against the compression spring 51. Then, according to the amount of the guide bar 60 to be fed, the amount of the tip 66 ejected from the long groove 62 increases, and the conical expanded portion is formed below the straight hole with the expansion of the rotation path drawn by the chip 66. It is.

[0007]

The conventional drilling and expanding tool has a structure in which the cylindrical body 50 rotates while directly pressing against the base, so that the rotational friction between the base and the cylindrical body 50 is large, and It was not easy to use because it was damaged and caused vibration and noise.

Further, since the tip 66 portion of the cutter blade 65 is formed so as to be expanded and perforated while being expelled from the long groove 62 of the guide bar 60 to the side, chips are clogged in the long groove 62 near the tip 66 and the This causes a trouble that the blade 65 does not operate.

Further, since the tip 66 is brazed to the tip of the cutter blade 65, if the tip 66 is worn or damaged, the entire cutter blade 65 must be replaced. It was economic.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and makes it easy to rotate the expanding tool during the expanding operation. It is an object of the present invention to improve an easy drilling and spreading tool.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylinder having a compression spring therein and a guide hole provided with two guide pins facing each other; A rotation receiving plate rotatably mounted, a drill shank mounted on the cylinder so as to be movable in the axis line against the compression spring, and a long groove inserted into the cylinder and opened at the tip end are provided. A guide bar having a rear end portion fixed to the drill shank, a perforation projecting a head from a tip of the guide bar, being inserted into the long groove, and rotatably supported by a pivot pin. A cutting edge tip made of cemented carbide is screwed flush in a rectangular recess along a warped surface of the head, and a rear end of the drilling cutter is closer to the guide bar. To the cutting edge tip side with respect to the axis of Kuraishi, was in contact with the cam surface on both sides to the guide pin.

[0012]

1 to 5 show a preferred embodiment of the present invention. A cylindrical body having two guide pins 8 and 9 provided in a guide hole 3 so as to face each other. 1, a rotation receiving plate 15 attached to the lower surface thereof, a drill shank 20 movably mounted on the cylindrical body 1 in an axial direction, and a guide bar 3 fitted into the cylindrical body 1 and fixed to the drill shank 20.
0, the boring cutter 4 supported by the guide bar 30
0.

The cylindrical body 1 has a guide hole 3 at the center of its bottom wall 2.
And the guide bar 30 is movably inserted in the axis. A compression spring 5 supported by the bottom wall 2 is provided inside the cylindrical body 1 along the inner wall, and the flange 21 of the drill shank 20 is supported by the compression spring 5 in a biased state. A stop ring 4 is fitted in the circumferential groove 6 inside the upper end of the opened cylinder 1 to prevent the drill shank 20 from coming out of the cylinder 1.

A disk-shaped rotation receiving plate 15 is rotatably mounted on the lower surface of the cylindrical body 1 via a bearing 16.

The drill shank 20 has a flange 21 formed at the base end thereof abutting against the compression spring 5 and is mounted on the cylinder 1 so as to be movable in the axis line against the compression spring 5. The protruding portion is clamped by a drill chuck (not shown) of the concrete drill.

The guide bar 30 is provided with a guide portion G comprising a long groove 31 having an open end, and a longitudinal engagement groove is provided on both outer sides of the guide portion G located in the cylindrical body 1. 32 are provided. This guide bar 30
Is inserted into the cylindrical body 1 and its rear end is fitted into the hole 22 of the drill shank 20 and fixed by the pin 23. The guide groove 3 of the cylinder 1 is provided in the engagement groove 32.
The distal end of the engaging pin 7 penetrating into the inside engages, so that the guide bar 30 and the cylindrical body 1 cannot rotate relative to each other and can move in the axis.

The drilling cutter 40 projects from the tip of the guide bar 30 with its head 41 inserted into the long groove 31 and is rotatably supported by a pivot pin 33 at the front of the guide bar 30.

The head 41 of the perforating cutter 40 has a warped surface 42 formed toward the tip thereof, and a rectangular recess 48 is engraved at the tip of the warped surface 42. A rhombus-shaped cutting tip 43 made of cemented carbide is flushly fixed along a warped surface 42 with a screw 47 so as to be detachable. Note that the cutting edge tip 43 is not limited to a diamond-shaped one, and may be a square-shaped one that can be firmly fixed along the warped surface 42 of the head 41.

The rear end of the perforating cutter 40 is displaced toward the cutting blade tip 43 with respect to the axis of the guide bar 30, and cam surfaces 44 and 45 are substantially parallel on both sides. Then, the cam surface 44 on the side of the cutting tip 43 and the tip of the guide pin 8 come into contact with each other, so that the amount of the head 41 centered on the pivot pin 33 in the direction of the cutting edge 46 of the cutting tip 43 is regulated. In addition, the cam surface 45 on the opposite side of the cutting edge tip 43 and the tip of the guide pin 9 come into contact with each other, and the amount of the head 41 that has been expelled and returned in the axial direction of the guide bar 30 is regulated. .

In order to use the present embodiment having the above-described structure, first, as shown in FIG. 4, a straight hole 26 is previously drilled in a base 25 such as concrete or bedrock by a normal drill. The guide bar 30 is made to enter the straight hole 26 by the operation of a concrete drill (not shown), and the rotation receiving plate 15 on the lower surface of the cylindrical body 1 is brought into contact with the upper surface 27 of the base 25.

The rotation receiving plate 15 abutted on the base 25 is stationary, and the cylindrical body 1 smoothly rotates on the rotation receiving plate 15. Therefore, the rotating state of the tool is maintained without damaging the base 25 or generating frictional noise due to the cylinder 1.

Next, the drill shank 20 is lowered against the compression spring 5 to increase the feed amount of the guide bar 30 into the straight hole 26. Then, the cam surface 44 on the cutting blade tip 43 side of the perforating cutter 40 is
The head 41 of the piercing cutter 40 projecting from the tip of the guide bar 30 slides toward the tip of the guide bar 30 in the direction from the axis of the guide bar 30 to the cutting edge 46 of the cutting tip 43 around the pivot pin 33. Driven to the cutting edge chip 4
The rotation trajectory drawn by 3 is gradually expanded.

The cutting blade tip 43 that rotates clockwise sequentially cuts the inner wall of the straight hole 26 to a large diameter, and advances while cutting chips are released along the warped surface 42 of the head 41. Therefore, a conical widening portion 28 is formed whose diameter increases as it goes deeper into the straight hole 26 (see FIG. 5).

After the expanding portion 28 is formed, the drill shank 20 is pulled back by the restoring force of the compression spring 5, and in the process, the perforating cutter 40 moves the cam surface 45 on the opposite side of the cutting blade tip 43 and the tip of the guide pin 9. The head 41 is guided by sliding, and the head 41 is
It is sequentially returned in the 0 axis direction. Then, the head 41 returns coaxially with the guide bar 30 at a position where the drill shank 20 has completely returned and the flange 21 has contacted the stop ring 4.

Therefore, the guide bar 30 can be easily pulled out from the inside of the straight hole 26 after the formation of the enlarged portion 28 by the operation of the concrete drill.

If the cutting tip 43 is worn or damaged, the screw 47 is removed and only the cutting tip 43 is replaced with a new one. In the case where the cutting edge 46 is formed on a plurality of sides of the rectangular cutting edge 43, the cutting edge 43 may be replaced at a position where a new cutting edge 46 can be used.

[0027]

The drilling and expanding tool of the present invention implemented in the above-described embodiment has the following effects.

The rotation receiving plate is rotatably mounted on the lower surface of the cylinder so that the base and the cylinder do not directly rub against each other, so that the rotation of the cylinder can be performed smoothly and noise and vibration can be reduced. it can. Therefore, even if a pressing force is applied to the rotating cylindrical body by lowering the drill shank, the surface of the base is not damaged, and the work can be performed without impairing the appearance.

Further, since the head of the drilling cutter is projected from the tip of the guide bar, and the head is provided with a warped surface, and the cutting blade tip is provided along the warped surface, the flow of the chips is smooth. Thus, the long groove of the guide bar is not clogged with chips, and the operation trouble of the perforating cutter is eliminated.

Further, since the cutting tip is fixed to the recess at the tip of the head by a screw along the warp surface so as to be detachable and flush with the screw, the cutting tip is firmly fixed in the recess. Even if it is worn or damaged, it is only necessary to replace only the cutting edge tip with a new one without replacing the drilling cutter, or to replace the cutting edge tip at a position where a new cutting edge can be used. Therefore, the maintenance of the perforating cutter is easy and economical.

[Brief description of the drawings]

FIG. 1 is a front view showing a cross section of a main part of a drilling and expanding tool according to the present invention.

FIG. 2 is a rear view showing a main part of the drilling and expanding tool shown in FIG. 1 in cross section.

FIG. 3 is a right side view of the drilling and expanding tool shown in FIG. 1;

FIG. 4 is a sectional view of a straight hole.

5 is a cross-sectional view of the straight hole of FIG.

FIG. 6 is a sectional view showing a conventional example.

[Explanation of symbols]

Reference Signs List 1 cylindrical body, 3 guide holes, 5 compression springs, 8 guide pins, 9 guide pins, 15 rotation receiving plates, 20 drill shank, 30 guide bars, 31 long grooves, 33 pivot pins, 40 drilling cutters, 41 head, 42 Warpage,
43 cutting edge tip, 44 cam surface, 45 cam surface, 48
Recess,

Claims (1)

[Claims] 1. A cylindrical body in which a compression spring is provided and two guide pins are provided in a guide hole so as to face each other, a rotation receiving plate rotatably mounted on a lower surface of the cylindrical body, and the compression spring. A drill shank mounted on the cylinder so as to be able to move in the axis line against the axis, and a long groove which is inserted into the cylinder and is opened at the front end, and a rear end portion is fixed to the drill shank. A guide bar, a drilling cutter having a head protruding from the tip of the guide bar and inserted into the long groove and rotatably supported by a pivot pin; A cutting edge tip made of cemented carbide is screwed flush into the rectangular recess, and a rear end of the drilling cutter is displaced closer to the cutting edge tip side with respect to the axis of the guide bar. A cam surface that contacts the guide pin on both sides A drilling and spreading tool characterized by the following.