JPH091413A - Core drill - Google Patents

Abstract

PURPOSE: To provide a core drill for preventing the playing of the joining part between a core body and a shunk during drilling work, by giving energizing force in a shaft direction to an engaging pin for joining the core body and the shunk. CONSTITUTION: A pair of L-shaped notched engaging grooves 6 are provided on the body fitting part 3 of a core body, a pair of grooves 20 are provided along a shaft direction on the connecting shaft 10 of a shank, and engaging pins 21 with a head part to be engaged in the grooves, and a guide ring 23 with a pin hole 24, are provided, to protrude the pin 21 from a pin hole 24 from the inner side of the ring 23 also insertedly fit the ring 23 into the shaft 10, and also the head part 22 of the pin 21 is insertedly fitted to the grooves 20 with energizing force in the shaft direction given. Consequently, the pin 21 can be engaged with the groove 6 of the fitting part 3 to join the core body and the shank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core drill, and more particularly to a core drill most suitable for drilling work such as concrete.

[0002]

2. Description of the Related Art A core drill for drilling concrete or the like comprises a cylindrical body having a center drill disposed at the center thereof, and the body and the center drill being connected to a shank. A cutting blade is provided on the periphery of the tip of the body, but it is difficult to remove the scraps of concrete that has entered the body because the cutting blade has a part that protrudes toward the inner peripheral surface of the body. .

In order to remove the dregs inside the body, the body and the shank are separated, and after the dross inside the body is removed, they are joined again. For this reason, it is desired that the body and shank be joined and separated as quickly as possible.

A conventionally proposed core drill of this kind is shown in FIG. 4 of Japanese Patent Laid-Open No. 4-269109. According to this known technique, an engaging projection 8 is provided on a body mounting portion, and the engaging projection 5 is formed on the core mounting portion 3.
The engaging groove 5 has a shallow depth toward the inner part. For this reason, when the engaging projection 8 is engaged in the engaging groove 5, the projection is pressed against the groove surface so that the both are joined. However, since vibration is repeatedly transmitted to the joint portion during the concrete drilling work, there is a risk that the joint of the two will be loosened during the drilling work and the joined state cannot be maintained.

[0005]

SUMMARY OF THE INVENTION The present invention is capable of preventing rattling of the joint between the core body and the shank during drilling work by applying an axial biasing force to the fastening pin that joins the core body and the shank. The purpose is to provide a core drill that can be easily attached and detached.

[0006]

Means for Solving the Problems In the present invention, means for solving the problems are a core body having a body mounting portion at the base end portion of a cylindrical body and a cutting blade at the peripheral edge of the tip end portion, and a tool at the base end portion. A core drill comprising a shank having a mounting shaft provided with a connecting shaft at a tip end thereof, wherein a pair of L-shaped notch engaging grooves provided in the body mounting part and a pair provided along the axial direction on the connecting shaft. Groove, a fastening pin with a head that fits into the groove, and a guide ring with a pin hole that fits into the connection shaft. The head of the fastening pin is inserted from the inside of the guide ring. Projecting from the pin hole toward the peripheral portion, and fitting the guide wheel into the groove by fitting the head of the fastening pin into the groove, and inserting the guide pin by applying an axial biasing force to the fastening pin, and projecting from the connecting shaft. Engage the notch engaging groove of the body mounting part with the fastening pin. It is characterized in combining the shank and.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 1 is a cylindrical core body, in which a body mounting portion 3 is provided at the base end portion of a cylindrical body 2 and a plurality of cutting blades 4 are provided at the peripheral edge of the tip end portion. A spiral groove 5 is formed on the entire outer peripheral surface of the core body 1. Further, the body mounting portion 3 is formed with a pair of notch engaging grooves 6 which are notched in the axial direction from the edge portion, are bent in the radial direction on the way, and are L-shaped when viewed from the front.

A shank 7 is provided with a tool attachment handle 9 at one end of a collar portion 8 provided in the central portion, which is a base end portion of the shank, and a tip end portion of the shank on the opposite side of the attachment handle. A connecting shaft 10 for connecting the core body 1 is formed in the portion. Reference numeral 11 is a drill hole formed along the axis in the center of the connecting shaft 10, and the hole reaches the flange 8.

A center drill 12 is inserted into the drill hole 11 of the shank 7 and is fixed by a hexagon socket set screw 13 provided on the flange 8 at the base. Reference numeral 14 is an O-ring fitted to the portion where the set screw 13 is provided.

The core body 1 is one in which the body mounting portion 3 is inserted into the connecting shaft 10 of the shank 7 and connected to the shank 7, and the center drill 1 shown in FIGS.
2 has a length protruding from the cutting edge 4 of the core body 1. Furthermore, the diameter of the core body 1 has various sizes so that desired holes can be drilled.

The connecting shaft 10 of the shank 7 is formed with a pair of grooves 20 parallel to each other along the axis from the tip end thereof, and a fastening pin 21 is accommodated in the groove 20. Groove 20
Is formed on the surface of the shaft like a key groove, and the fastening pin 21 is provided with a head 22 having a diameter larger than that of the pin. The fastening pin 21 fits the head 22 into the groove 20,
In the embodiment, the head 22 is provided with a parallel notch 22a that matches the width of the groove 20 and is fitted therein.

Reference numeral 23 is a guide wheel for applying an axial urging force to the fastening pin 21, which has a pair of pin holes 24 in the center of the body. The pin hole 24 is formed in a size such that the fastening pin 21 can project without a gap. The guide wheel 23 is inserted into the connecting shaft 10 of the shank 7, but in order to apply an axial biasing force to the guide wheel 23, that is, the fastening pin 21, the compression coil spring 25, the ring 26,
A C-shaped retaining ring 27 is used. Further, a ring groove 28 for engaging the C-shaped retaining ring 27 is formed on the outer peripheral portion of the tip of the connecting shaft 10.

Next, the procedure for connecting the body and the shank will be described. First, from the inside of the guide ring 23, the pin hole 24
The fastening pin 21 is inserted into the guide ring 23, and the pin is projected to the outside of the guide ring 23.
The guide wheel 23 is fitted into the connecting shaft 10 while fitting into 0. Next, the compression coil spring 25 and the ring 26 are inserted into the connecting shaft 10 and the C-shaped retaining ring 27 is engaged with the ring groove 28 to assemble the shank 7.

The fastening pin 21 protruding from the shank 7 thus constructed is given an urging force in the axial direction, more specifically, toward the collar portion 8. Further, the center drill 12 is inserted into the drill hole 11 provided at the center of the connecting shaft 10 and the set screw 13
The center drill 12 is fixed by.

In the core body 1, the body mounting portion 3 is inserted into the connecting shaft 10 of the shank 7, and the notch engaging groove 6 is formed in the connecting shaft 10.
Engaging with the fastening pin 21 protruding from the
When 1 relatively moves in the notch engagement groove 6 and reaches the corner of the engagement groove, the body is rotated to accommodate the pin in the inner part.
Since the notch engagement groove 6 is L-shaped, the fastening pin 21
The pin will not come out if the groove reaches the inner part of the groove, but a bulged part 6a is formed in the inner part of the groove, and if the pin fits in this bulged part 6a, the connection between the two is held stably. it can.

The connection between the body and the shank is performed by a so-called one-touch operation. That is, it is performed by inserting the shank attachment portion 3 into the connecting shaft 10 and then rotating the same, and when separating them, the body is rotated and then withdrawn. The fastening pin 21 is biased by the compression coil spring 25 pressing the guide wheel 23 in the axial direction, so that the core body and the shank are stably coupled.

[0017]

According to the present invention, since the fastening pin for connecting the body and the shank is provided so as to be movable in the axial direction and biased in the axial direction, the connecting portion between the body and the shank is stable and stable. The connected state can be maintained, and the body and the shank can be attached and detached by a so-called one-touch operation, so that workability when exchanging the body is good.

[Brief description of the drawings]

FIG. 1 is a side view in which the whole is assembled.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a front view seen from the shank side.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a parts diagram.

[Explanation of symbols]

 1 Core Body 2 Cylindrical Body 3 Body Attachment Part 4 Cutting Edge 5 Spiral Groove 6 Spiral Engagement Groove 6a Swelling Part 7 Shank 8 Collar Part 9 Tool Attachment Handle 10 Connecting Shaft 11 Drill Hole 12 Center Drill 13 Set Screw 14 O-ring 20 Groove 21 Tightening Pin 22 Head 22a Parallel Notch 23 Guide Ring 24 Pin Hole 25 Compression Coil Spring 26 Ring 27 C-Type Retaining Ring 28 Ring Groove

Claims (6)

[Claims] 1. A body mounting portion of a core body, comprising: a core body having a body mounting portion provided at a base end portion of a cylindrical body and a cutting blade provided at a peripheral edge of a distal end portion; and a shank having a tool mounting handle provided at a base end portion thereof. Alternatively, in a core drill in which an L-shaped notch engaging groove is provided on one of the shanks, a fastening pin is provided at the other, and the fastening pin and the notch engaging groove are engaged to couple the two.
A core drill, wherein the fastening pin is movable in the axial direction and is given a biasing force in the axial direction. 2. The core drill according to claim 1, wherein the notch engaging groove is provided in a pair on the body mounting portion of the core body, and the fastening pin is provided in a pair on the shank. 3. The fastening pin has a head provided at one end, and the head is slidably fitted in a groove provided along the axial direction of the shank. The core drill according to claim 2. 4. The fastening pin is inserted from the inside of a pin hole provided in the guide wheel to project to the outer peripheral portion of the guide wheel, and the head is fitted in a groove provided in the shank to be fitted to the shank together with the guide wheel. The core drill according to claim 3, wherein the core drill is attached. 5. The core drill according to claim 4, wherein the guide wheel is axially biased by a compression coil spring. 6. A core body having a body mounting portion at the base end portion of a cylindrical body and a cutting blade at the peripheral edge of the tip end portion, and a shank having a tool mounting handle at the base end portion and a connecting shaft at the tip end portion. In the core drill, a pair of L-shaped notch engaging grooves provided in the body mounting portion, a pair of grooves provided in the connecting shaft along the axial direction, and a fastening with a head fitted in the groove It has a pin and a guide wheel with a pin hole to be fitted into the connecting shaft, the head of the fastening pin projects from the inside of the guide wheel toward the inner peripheral portion, and the guide wheel is fastened. The head portion of the pin is fitted in the groove and the compression coil spring is superposed and inserted, and the notch engaging groove of the body attaching portion is engaged with the fastening pin protruding from the outer peripheral portion of the connecting shaft to form the core body. A core drill characterized by joining shanks.