JPH0929524A - Drill blade for hand drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely drill a hole of a large diameter. SOLUTION: A lead blade 5 of a smaller diameter than that of a drill blade body 1 is integrated on the tip of the drill blade body 1 to be removably fitted to a hand drill D to realize the drilling by the drill blade body 1 after a hole 14 is formed by the lead blade 1 during the drilling work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drill blade for a hand drill that facilitates large-diameter drilling.

[0002]

2. Description of the Related Art Conventionally well-known drill blades for hand drills are said to be provided with a spiral cutting edge and a conical cutting edge on the outer peripheral surface and the tip end surface. It is said that the conical cutting blade starts the perforation on the metal-made member to be perforated, and then the spiral cutting blade performs the perforation.

[0003]

However, when a large-diameter hole is drilled, the outer diameter of the drill blade naturally increases, so that the spiral cutting edge tends to slip at the start of drilling. However, it may be difficult to perforate the member to be punched.

The present invention has been made in view of the above points, and it is an object of the present invention to make it possible to easily and surely make a large-diameter hole.

[0005]

In the basic constitution of the present invention, as means for solving the above-mentioned problems, as a means for solving the above-mentioned problems, a tip of a drill blade body detachably mounted on a hand drill has a diameter smaller than that of the drill blade body. The lead blade is integrally formed so that during the drilling operation, the drill blade body can be used for drilling after the formation of the hole by the lead blade.

In the basic structure of the present invention, the drill blade main body is provided with a stopper for controlling the drilling depth by the drill blade main body so that the drilling depth by the drill blade main body can be regulated to a predetermined depth and excessive penetration can be prevented. It is preferable because it can be prevented. In that case, on the lower surface of the stopper,
It is more preferable to form a chamfering blade that chamfers the opening edge of the hole drilled by the drill blade main body in that it can also curl removal and chamfering simultaneously with the regulation of the drilling depth.
It is more preferable that the stopper is vertically adjustable with respect to the drill blade body in terms of freely adjusting the drilling depth by the drill blade body, and further, the stopper is externally inserted into the drill blade body. It is more preferable to use a cylindrical body and also serve as a mounting member for the hand drill, from the viewpoint that the structure can be simplified.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First Embodiment FIGS. 1 to 4 show a drill blade for a hand drill according to a first embodiment of the present invention.

The drill blade for a hand drill according to the present embodiment is mainly used for making a hole in a metal, and a drill blade body 1 which is detachably attached to a hand drill D. , And a stopper 2 for regulating the depth of drilling by the drill blade body 1.

The drill blade body 1 has a hole 1 having a predetermined inner diameter.
The cutting edges 3 and 4 are formed on the outer peripheral surface and the tip end surface, respectively. Further, a lead blade 5 having a smaller diameter than that of the drill blade body 1 is integrally formed at the tip of the drill blade body 1.
Cutting edges 6 and 7 are formed on the outer peripheral surface and the front end surface, respectively. The lead blade 5 forms the perforation 14 in the object W to be drilled prior to the drilling by the drill blade body 1, which may occur when the large hole 10 is drilled by the drill blade body 1. The drilling work can be performed easily and surely without causing a slip.

The stopper 2 is the drill blade body 1
A chamfering blade 8 for chamfering an opening edge 10a of a hole 10 formed by the drill blade body 1 is formed on a lower surface of the cylindrical body that is vertically slidably fitted into the cylindrical body.
Are formed. This stopper 2 is indicated by an arrow A in FIG.
Alternatively, it can be slid by a predetermined dimension in the B direction, and the drilling depth is set by the dimension of the drill blade body 1 protruding downward from the stopper 2. In other words, the stopper 2 regulates the drilling depth.
At the same time as the adjustment, curl removal and chamfering are to be performed.

Further, a plurality of slits (9, 9) extending downward from the upper end are formed in the upper portion of the stopper 2 at equal intervals in the circumferential direction, and the slits 9, 9, 9 are formed. By inserting the portion where the is formed into the drill blade chuck 12 in the hand drill D and tightening the drill blade chuck 12 with the tightening screw 13,
The drill blade body 1 is to be attached to the hand drill D integrally with the stopper 2. That is, the stopper 2 also serves as a mounting member for the hand drill D. Reference numeral 11 is the slit 9,
It is a vertical groove formed between 9, 9 and has a function of ensuring chucking by the drill blade chuck 12.

Next, a detailed description will be given of the drilling work using the above-configured drill blade for a hand drill.

First, after the position of the stopper 2 on the drill blade body 1 is determined in accordance with the drilling depth, the drill blade body 1 is mounted and fixed to the hand drill D. Under this state, the lead blade 5 is applied to a predetermined position of the member W to be punched and the hand drill D is driven. Then, the lead blade 5 first forms a small perforation 14 (see FIG. 2) in the member W to be punched, and then the drill blade main body 1 makes
0 (see FIG. 1) is formed. Then, when the depth of the hole 10 reaches a predetermined size, the stopper 2 moves the opening edge 1 of the hole 10.
0a, the further penetration of the drill blade body 1 is restricted, and the chamfering blade 8 chamfers the opening edge 10a. Therefore, it is possible to easily and surely form the hole 10 with a predetermined depth without causing the conventional problems (damage of internal wiring, parts, etc. due to penetration of the drill blade or scratches on the surface of the member to be drilled). It is possible to remove the curl or the like generated at the opening edge 10a of the hole 10 and chamfer at the same time.

The drilling depth is mainly adjusted by replacing the stopper 2, but the depth adjustment of about 10 mm is performed by sliding the stopper 2.

Second Embodiment FIG. 5 shows a drill blade for a hand drill according to a second embodiment of the present invention.

In this case, the stopper 2 is a collar-shaped member integrally formed at a predetermined position of the drill blade body 1 (that is, the upper end position of the spiral cutting blade 3). In other words, the structure is such that the position adjustment of the stopper 2 (that is, the adjustment of the drilling depth) cannot be performed. Therefore, it is necessary to prepare a number of drill blade bodies corresponding to the required drilling depth in advance and replace the drill blade bodies at the work site as needed, but the structure is robust. The other configuration and operation and effect are the same as those of the first embodiment, and the description is omitted.

[0018]

According to the present invention, a lead blade having a smaller diameter than that of the drill blade body is integrally formed at the tip of the drill blade body, and the hole is formed by the drill blade body after the formation of the hole by the lead blade during the drilling operation. Since it is possible to perform drilling, it is possible to effectively avoid the phenomenon that the drill blade body slips at the start of drilling, and it is possible to drill easily and reliably even when drilling large diameter holes. There is an effect.

[Brief description of drawings]

FIG. 1 is a side view with a part omitted showing a hand drill having a drill blade according to a first embodiment of the present invention.

FIG. 2 is a side view showing an initial state of drilling with a hand drill having a drill blade according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a drill blade for a hand drill according to the first embodiment of the present invention.

FIG. 4 is a bottom view of the drill blade for the hand drill according to the first embodiment of the present invention.

FIG. 5 is a side view with a part omitted showing a hand drill having a drill blade according to a second embodiment of the present invention.

[Explanation of symbols]

1 is a drill blade body, 2 is a stopper, 3 is a spiral cutting blade,
4 is a conical cutting edge, 5 is a lead blade, 6 is a spiral cutting edge, 7 is a conical cutting edge, 8 is a chamfering edge, 10 is a hole, 14 is a perforation, D
Is a hand drill and W is a member for drilling.

Claims (5)

[Claims] 1. A drill blade for a hand drill, characterized in that a lead blade having a diameter smaller than that of the drill blade body is integrally formed at a tip of the drill blade body detachably attached to the hand drill. . 2. The drill blade for a hand drill according to claim 1, wherein the drill blade body is provided with a stopper that regulates a drilling depth of the drill blade body. 3. The drill for a hand drill according to claim 2, wherein a chamfering blade that chamfers an opening edge of a hole formed by the drill blade body is formed on a lower surface of the stopper. blade. 4. The drill blade for a hand drill according to claim 2, wherein the stopper is vertically adjustable with respect to the drill blade main body. 5. The stopper according to claim 2, wherein the stopper is a cylindrical body that is externally inserted into the drill blade main body, and also serves as a mounting member for the hand drill. A drill blade for a hand drill according to item 1.