JPH11114848A - Bit and working tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely attach a bit on a bit attaching part of a working tool. SOLUTION: This tool is provided with an attaching part 2 made of plastics and a bit main body 3 made of steel of which cross section area is 25% or less of the cross section of the attaching part 2 and its rear end side is buried in the attaching part 2. The rear end side of the attaching part 2 is formed to be a conical taper part 5. By this, the rear end side of the attaching part (the conical taper part 5) can be securely fixed by surely pressing and abutting in the bit insert hole of a working tool main body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a bit and a power tool.

[0002]

2. Description of the Related Art Conventionally, a bit of a working tool such as a hand driver or a charging driver having a detachable tip bit has a chamfered portion a at a base end as shown in FIG. 8, for example. The mounting portion b was made of metal and has a hexagonal cross section, and a bit main body c integrally formed at the tip of the mounting portion b. On the other hand, in a bit insertion hole e provided in the bit attachment portion d of the power tool, a sphere h is provided so as to be removably engaged with a circumferential groove g formed on the outer surface of the bit f, and At the back of the bit insertion hole e, an inclined surface portion i whose diameter gradually decreases toward the back is formed.

[0003]

However, in the above-described conventional bit holding structure, the chamfered portion a at the base end of the bit f is formed.
Does not firmly hit the inclined surface portion i at the back of the bit insertion hole e, so that there is a problem that the bit is shaken when the work tool is strongly pushed toward the distal end.

Accordingly, an object of the present invention is to solve the above-mentioned problem and to provide a bit which can be attached to a bit attachment portion of a power tool without shaking.
It is another object of the present invention to provide a power tool in which a bit does not fluctuate even if the bit is pushed strongly toward the distal end.

[0005]

In order to achieve the above object, a bit according to the present invention has a conical tapered portion on a base end face. The mounting portion is made of a non-ferrous material, and includes a steel bit body having a base end buried in the mounting portion and having a small cross-sectional area of less than 25% of a cross-sectional area of the mounting portion. It also comprises a plastic mounting portion having a substantially hexagonal columnar shape and having a notch ball retaining concave peripheral groove on its outer surface, and a steel bit main body having a small cross-sectional area of less than 25% of the cross-sectional area of the mounting portion.

The power tool according to the present invention also includes a mounting portion made of a non-ferrous material, a steel bit body having a small cross-sectional area less than 25% of a cross-sectional area of the mounting portion, the base end of which is buried in the mounting portion. A conical taper portion is formed on the base end surface of the bit composed of, and a plurality of types of bits formed with a notch ball locking concave peripheral groove on the outer surface of the mounting portion constitute a uniform bit set, From the bit set, the above-mentioned bit is selectively selected so that it can be attached to a power tool main body with a notch ball. Further, the power tool body has an inner cylinder body having a bit insertion hole opened on the tip side, and an outer cylinder body slidably fitted to the inner cylinder body in the axial direction and having a notch ball receiving ridge. A resilient member disposed between the inner cylinder and the outer cylinder and for urging the outer cylinder toward the proximal end side with respect to the inner cylinder, and a peripheral wall of the inner cylinder; A notch ball that is loosely fitted in the radial hole formed therethrough and that is detachably engageable with a notch ball engaging concave peripheral groove provided in the bit.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the illustrated embodiments.

FIG. 5 shows an embodiment of a power tool according to the present invention. The power tool is a rechargeable tool having a storage battery and a rotary drive mechanism.
And a work tool main body 6 to which is detachably attached. Thus, as shown in FIG. 1 and FIG.
Is detachably attached to the power tool body 6, and has a mounting portion 2 made of a non-ferrous material, a small cross-sectional area having a base end side embedded in the mounting portion 2 and less than 25% of a cross-sectional area of the mounting portion 2. And a steel bit main body 3.

The mounting portion 2 is made of plastic having a substantially hexagonal column shape and a notched ball locking concave peripheral groove 4 on its outer surface, and has a conical taper portion 5 on the base end surface. If the cross-sectional area of the bit body 3 exceeds 25% of the cross-sectional area of the mounting portion 2, the thickness of the mounting portion 2 becomes too small, and the strength of the mounting portion 2 becomes insufficient.

Thus, as shown in FIG. 3, a plurality of kinds of bits 1... With only the shape of the tip end of the bit body 3 being changed are formed to form a uniform bit set S. Specifically, the tip of the bit 1 is a plus screw fitting 7, the tip of the bit 1 is a minus screw fitting 9, and the tip of the bit 1 is a hexagon bolt Alternatively, a hexagonal hole portion 10 to be fitted to the nut is formed, and the tip of the bit 1 is formed as a needle-like tip 11 like an awl.
Is formed as a wood screw-shaped tip 12. Then, the bit 1 is selectively selected from the bit set S, and can be attached to the power tool body 6 with the notch ball 13.

As shown in FIG. 4, the bit mounting portion 8 at the distal end of the power tool body 6 has an inner cylindrical body 15 having a hexagonal cross section bit insertion hole 14 opened to the distal end side, and an inner cylindrical body 15. An outer cylinder 17 slidably fitted in the direction of the axis L and having a notch ball receiving ridge 16, and an inner cylinder 15 disposed between the inner cylinder 15 and the outer cylinder 17. A resilient member 18 for resiliently urging the outer cylinder 17 toward the base end and a radial hole 19 formed through the peripheral wall of the inner cylinder 15 are loosely fitted and provided on the bit 1. Notch balls 13 which can be detachably engaged with the notch ball engaging concave peripheral groove 4.

The notch ball is formed in the radial hole 19.
13 is fitted so as to be slightly movable in a direction parallel to the axis L. A small circumferential groove 21 is formed in the vicinity of the distal end of the outer peripheral surface of the inner cylindrical body 15, and the ring body 22 is fitted into the small groove 21 so as to protrude outward. And notch ball receiving strip
A coil-shaped resilient member 18 and a retaining ring 23 are interposed between the ring member 22 and the ring member 16. The notch ball receiving ridge 16 has a holding inner peripheral surface 26 that is parallel to the axis L in a longitudinal sectional shape, and a bit insertion guiding slope surface that extends diagonally outward from the base end of the holding inner peripheral surface 26. 27.

A contact portion 20 for receiving the base end of the mounting portion 2 of the bit 1 is provided in the inner cylindrical body 15 at the depth of the bit insertion hole 14. That is, the small diameter hole 24 is provided in the depth of the bit insertion hole 14, and the inner peripheral edge of the stepped portion between the small diameter hole 24 and the bit insertion hole 14 is the contact portion 20.

With the above-described configuration, the conical taper portion 5 of the mounting portion 2 of the bit 1 firmly contacts the contact portion 20 of the bit insertion hole 14 of the bit mounting portion 8.
Therefore, in the case of rotating a screw, etc., even if the bit 1 is rotated while pressing the power tool toward the tip side of the bit 1 with a strong force, the bit 1 does not shake and is stable around the axis L. Can be rotated.

In addition, the bit 1 having a desired tip shape can be selected from the bit set S shown in FIG. 3 and can be easily replaced. In this case, as shown by an arrow D in FIG. 4, the outer cylindrical body 17 of the bit attaching portion 8 is moved to the distal end side. As a result, the notch ball receiving ridges 16 move toward the distal end, so that the notch balls 13 can escape outward, and the bit 1 can be pulled out with a light force.

In addition, in order to attach bit 1, bit 1
May simply be inserted into the bit insertion hole 14 of the bit mounting portion 8. That way, during insertion,
When the conical tapered portion 5 at the base end of the bit 1 hits the notch ball 13, the notch ball 13 slightly moves from the holding inner peripheral surface 26 of the notch ball receiving ridge 16 toward the induction slope surface 27, and the notch ball 13 Can escape to the outside. That is, bit 1
Is exerted on the guiding gradient surface 27 via the notch ball 13 to generate a component force toward the distal end, and the outer cylindrical body 17 moves toward the distal end due to the component force. Thereafter, the notch ball 13 is automatically fitted into the notch ball retaining concave groove 4 of the bit 1.

As described above, according to the power tool, the bit 1 can be easily attached to and detached from the power tool main body 6 quickly. Then, the base end portion of the bit 1 {that is, the conical taper portion 5} of the mounting portion 2 can be securely pressed and abutted on the deep portion of the bit insertion hole 14 of the power tool body 6 to be fixed. . Therefore, even when the power tool is strongly pushed toward the distal end when the power tool is used, the bit 1 does not wobble, and can be rotated while being pressed with a strong force.

Further, since the mounting portion 2 of the bit 1 is made of plastic, the base end of the steel bit main body 3 can be easily buried, thereby facilitating the manufacture of the bit 1. Further, the bit body 3 can be made extremely thin, and is most suitable for rotating extremely small screws used in watches, glasses, and the like.

The bit 1 can correspond to a general-purpose power tool body 6 as shown in FIGS. That is,
In general, an inclined surface portion 31 whose diameter is gradually reduced toward the back is formed in the depth of the bit insertion hole 30 of the bit attachment portion 29 at the tip of the general-purpose power tool body 6. According to the bit 1, the conical taper portion 5 at the base end of the mounting portion 2 is firmly abutted and fixed to the inclined surface portion 31 of the bit insertion hole 30 of the bit mounting portion 29, so that the bit 1 is loose. There is nothing
It can be rotated while being pressed against the distal end with a strong force. In FIG. 6, reference numeral 13 denotes a notch ball, and reference numeral 33 denotes a resilient member for pressing the notch ball 13 inward. FIG.
In the figure, reference numeral 34 denotes a handle, and the power tool body 6 is a manual type.

Further, it is possible to use this bit 1 alone. In this case, the bit body 3 and the conical taper portion 5 may be supported by one hand, and the mounting portion 2 may be rotated by the other hand (see FIG. 1).

The power tool of the present invention may be an air driver that is driven to rotate by air pressure in addition to the above-mentioned electric or manual power tool. Also,
The shape and size of the tip of the bit body 3 of the bit 1 are shown in FIG.
May be added. For example, several types of bits 1 in which the size (outer diameter) of the plus screw fitting portion 7 and the minus screw fitting portion 9 are slightly different may be added. Further, the material of the mounting portion 2 of the bit 1 may be other than plastic, for example, hard rubber can be used.

[0022]

The present invention has the following remarkable effects by the above-mentioned structure.

According to the first aspect of the present invention, the base end surface (conical taper portion 5) of the mounting portion can be securely pressed and abutted on the deep portion of the bit insertion hole of the power tool body to be fixed. . Therefore, even when the work tool is used, even if it is strongly pushed to the distal end side, the bit does not fluctuate, and the work can be performed while being pressed with a strong force.

According to the bit of the second aspect, the bit body 3 can be made extremely thin, and is most suitable for rotating extremely small screws used for watches, glasses, and the like. Moreover, manufacture becomes easy. Also, when manufacturing the bit body 3
Since almost no cutting is required, material can be saved.
According to the bit of the third aspect, the bit main body 3 can be made extremely thin, and is most suitable for rotating extremely small screws used for watches, glasses, and the like. Moreover, manufacture becomes extremely easy. Further, since the bit body 3 is hardly required to be cut at the time of manufacturing, the material can be saved. Further, the notch ball of the power tool body 6 is inserted into the notch ball locking concave circumferential groove 4 of the mounting portion 2 which is sufficiently thicker than the
Since bit 13 is inserted, bit 1 is not loose.

According to the power tool of the fourth aspect, the conical taper portion 5 of the bit 1 can be securely pressed and abutted against the deep portion of the bit insertion hole of the power tool body 6 to be fixed. Even when the work tool is used, even if it is strongly pushed to the distal end side, the bit 1 does not fluctuate, and the work can be performed while being pressed with a strong force. Further, the bit 1 can be applied to the general-purpose power tool body 6.

According to the power tool of the fifth aspect, the same effects as those of the fourth aspect can be obtained, and the bit 1
Can be attached to and detached from the power tool body 6 easily and quickly.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a bit according to the present invention.

FIG. 2 is an enlarged sectional front view.

FIG. 3 is a side view of a bit set.

FIG. 4 is an enlarged sectional view of a main part of the power tool according to the present invention.

FIG. 5 is a side view of the power tool.

FIG. 6 is an enlarged sectional view of a main part in another usage method.

FIG. 7 is a side view in another usage method.

FIG. 8 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 2 Mounting part 3 Bit body 4 Notch ball retaining concave groove 5 Conical taper part 6 Work tool body 13 Notch ball 14 Bit insertion hole 15 Inner cylinder 16 Notch ball receiving ridge 17 Outer cylinder 18 Resilient member 19 Radial direction Hole S Bit set L Shaft center

Claims (5)

[Claims] 1. A bit having a conical tapered portion 5 on a base end face. 2. A mounting portion 2 made of a non-ferrous material, a base end side of which is embedded in the mounting portion 2 and a cross-sectional area of the mounting portion 2 is reduced.
A steel bit body 3 having a small cross section of less than 25%. 3. A plastic mounting portion 2 having a substantially hexagonal column shape and having a notch ball retaining concave circumferential groove 4 on its outer surface, and a steel bit having a small cross-sectional area of less than 25% of the cross-sectional area of the mounting portion 2. And a main body (3). 4. A bit comprising: a mounting portion 2 made of a non-ferrous material; and a steel bit main body 3 having a base portion buried in the mounting portion 2 and having a small cross-sectional area of less than 25% of a cross-sectional area of the mounting portion 2. A conical tapered portion 5 is formed on the base end surface of the base 1 and a plurality of types of bits 1... A power tool comprising the bit set S, wherein the bit 1 is alternatively selected and can be attached to the power tool body 6 with the notch ball 13. 5. A power tool main body 6 has an inner cylinder 15 having a bit insertion hole 14 opening on the distal end side, and the inner cylinder 15 has an axial center L.
An outer cylinder 17 having a notch ball receiving ridge 16 which is slidably fitted in the outer direction and disposed between the inner cylinder 15 and the outer cylinder 17 and the inner cylinder 15 A resilient member 18 for resiliently urging the outer cylinder 17 toward the base end and a radial hole 19 penetrating through the peripheral wall of the inner cylinder 15 are loosely fitted and provided on the bit 1. The power tool according to claim 4, further comprising a notch ball (13) removably engageable with the notch ball engaging concave circumferential groove (4).