JPS59107815A - Core drill - Google Patents

Abstract

PURPOSE:To contrive an improvement in durability of the whole of a drill and saving in material by making only a tip holder exchangeable at the time of wear of a tip, by fixing the tip holder, the circumferential face of the tip of which is provided with a plurality of tips, on the tip of a drill body detachably and attachably. CONSTITUTION:A core drill is constituted by connecting a tip holder 2 with the tip of a drill body 1 detachably and attachably. In this instance, as for a drill body 1, a flat parts 11 for securing a chuck and a spiral protrusion strips are formed respectively on both sides of a base end and the external circumference of a metallic cylinder, a plurality of concave parts 12 confronted with each other on a diametral line is formed on the top of the metallic cylinder and the bottom of the recessed part 12 is provided with a screw hole 13. On the other hand, as for the tip holder 2, a plurality of tips 21 is secured on the circumferential face of the tip of the metallic cylinder at identical intervals, a protruded part 22 fitted in with the recessed part 12 of the above-mentioned body 1 is provided on a base end face in a protruded state and a shaft hole 23 is provided in a confronting state with the above-mentioned screw hole 13. Then the above- mentioned body 1 and the holder 2 are connected with each other by screwing a screw shaft 24 into the screw hole 13 and the shaft hole 23.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a core drill used for drilling into floors, walls, etc.

Conventionally, new types of core drills have been fixed by directly attaching multiple chins to the tip of the drill body. Therefore, when a tip breaks, the entire drill must be replaced with a new one, which is extremely uneconomical. be. For this reason, there has recently been a strong demand in the industry for a core drill that connects a holder with a tip and a cutting tool body in a detachable manner so that only the tip holder can be replaced when the chimp breaks. , currently no such thing exists.

The present invention provides a novel core drill that satisfies the above requirements with an extremely simple configuration and is effective in saving materials.

The core drill of the present invention, which will be described in detail below based on the embodiments shown in the drawings, has a tip holder (2) having a plurality of tips removably connected to the tip of the drill body f1+. . As is well known, the drill body (1) has flat parts for fixing the chuck on both sides of the base end of the metal cylinder.
11), a spiral protrusion (not shown) is formed on the outer periphery, and a plurality of four parts (12) are formed on the tip surface corresponding to the diameter line.
A screw hole (13)' is bored in the bottom of the fourth part (12).

The tip holder (2) is a metal cylinder with a constant thickness and length, and has concave portions at five equal intervals on the circumferential surface of the distal end to hold the tip @I (fixed on the proximal surface and fixed on the proximal surface). A coupling convex portion (2) that fits into the concave portion (12) of the main body (1) is provided protrudingly, and a screw hole (MfJ) is provided in the center of the convex portion (2).
Drill the shaft hole (4) corresponding to the hole (13), and insert the convex part (
When 22 is engaged with the recess of main body f1+, the screw hole (13) matches the shaft hole (23), and the screw shaft (24) is inserted there.
) is screwed in to integrally connect the main body (1) and the holder (2).

In the embodiment shown in FIG. 3, the diameters of the tip holder (2) and the drill body m are different in size. ), and therefore, several large and small chip holders (2) are used for the wooden drill body fl+.
Can be supplied as a set.

However, in the core drill of the present invention, the shaft is fixed to a chuck (not shown) of a rotary drive device in the same manner as in the past, and the drilling operation is performed.When the drill body i11 is rotationally driven, the tip holder (2) - Due to the connection of the recess (12), it pivots together with the main body (l) and makes a hole in the floor or wall! 7 Now, when the tip is worn out or damaged, loosen the screw shaft (24I) and remove the whole body + 1 +
It can be used in the same manner as described above by removing the tip holder (2) from the tip, fitting a new tip holder (2) there, and fixing it with screws.

°As described above, in the present invention, the tip holder (2) is completely removably attached and fixed to the tip of the drill body +1+.

When the tip wears out or breaks, only the tip holder needs to be replaced, which improves durability and efficiency compared to conventional products, and saves on materials.

In addition, the present invention has the effect of achieving the object of the invention by simplifying the structure, such as by supplying a plurality of large and small tip holders as a set to the wooden drill body.

[Brief explanation of drawings]

FIG. 1 is a perspective view, FIG. 2 is a longitudinal sectional view, and FIG. 3 is a sectional view showing another embodiment. i11 Drill body (11) Flat part (12) Four parts (2) Tip holder (21) Tip (four convex parts
(2(1) Screw shaft

Claims (1)

[Claims] A drill body (1) having a chuck fixing flat part (11)'(r) at the base end, and a drill body (1) having a flat part (11)'(r) for fixing the chuck at the base end, and a drill body (1) that is detachably attached to the tip of the drill body (=
J-cut, with multiple tips at equal intervals on the circumferential surface of the tip (2)
1) A core drill consisting of a fully deployed tip holder (2),