JPH08323636A - Box bit - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a box bit that securely fits a screw head and prevents damage to the screw head. [Structure] A fitting hole 2 into which a head of a hexagon bolt or the like fits,
In a box bit formed with a connecting portion that can be detachably connected to various screw tightening means, a notch portion 6 is formed on the end surface where the fitting hole portion 2 is provided. The notch 6 is formed to have, for example, an inclined portion 6a that is inclined with respect to the end face, and is formed into an arcuate portion 6b from the outer peripheral side to the fitting hole portion. [Effect] Since the present invention is provided with a notch at the edge of the end face,
Even if the axis of the box bit and the axis of the fastening part such as a hexagon bolt do not match, it is possible to match them to properly engage the box bit with the hexagon bolt. Since it has an arcuate portion extending from the outer periphery of the bit to the fitting hole, it is possible to prevent damage to the head when engaging the fastening component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box bit used for tightening, for example, a hexagonal bolt, and more particularly to a box bit in which a screw head is reliably inserted into a fitting hole.

[0002]

2. Description of the Related Art Conventionally, when a threaded component such as a hexagonal bolt having no driving hole formed in its head is fastened to a work, it has a fitting hole portion conforming to the head shape of the screw component. Box bits are used.

[0003]

In the above box bit, since the fitting hole portion has to be fitted in the head portion of the screw part, it is necessary to make its axis coincide with the axis of the screw part crystal. When used in an automatic machine such as an automatic screw tightener, there is a problem that screw tightening failure is likely to occur unless control is performed so as to perform accurate positioning during work.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a box bit that can be securely fitted to a screw head and can prevent damage to the screw head. To do.

[0005]

In order to achieve the above object, a box bit formed with a fitting hole into which a screw head is fitted and a connecting portion that can be detachably connected to various screw fastening means. In, the notch is formed on the end face where the fitting hole is provided. The cutout portion is formed to have, for example, an inclined portion that is inclined with respect to the end surface, and is also formed to have an arcuate portion from the outer peripheral side to the fitting hole portion. The cutout portion can be formed in a loop shape whose height increases in accordance with the rotation direction at the time of screw tightening with reference to a certain point on the outer circumference of the end face.

[0006]

In the above box bit, when the fitting hole is engaged with the head of the screw and the axis of the box bit and the axis of the screw do not match, the end surface of the box bit is screwed to the head. When a rotational force is applied in the state of being brought into contact with the upper surface and rotated in the screw tightening direction, the notch of the box bit comes into contact with the side surface of the screw head. When the box bit is further rotated, the screw head moves along the step, so the axis of the screw gradually moves to the box bit axis side, and finally the box bit fitting hole is the screw head. Engage with. Therefore, even if the axes do not match, reliable screw tightening can be performed. Also, by forming the end of the notch into an arcuate portion, damage to the side surface of the screw head can be prevented, while wear on the tool side can also be prevented and the tool life can be extended.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, reference numeral 1 is a box bit, and a screw having a polygonal head shape, for example, a fitting hole 2 that fits into a head 7 of a hexagonal bolt is formed at one end thereof. The peripheral wall surface of the fitting hole portion 2 is formed in a dodecagonal shape so that the hexagonal bolt can be easily fitted into the head portion 7. At the other end of the box bit 1, there is provided a connecting portion 3 that can be connected to an output shaft (not shown) of a driver unit which is an example of screw tightening means. In this embodiment, the connecting portion 3 is formed of a screw, and is screwed into a female screw portion (not shown) formed on the output shaft of the driver unit so that the connecting portion 3 can be connected to the driver unit. Further, the outer peripheral surface of the box bit 1 is provided with a so-called double chamfer 4 having a flat surface portion at a facing position, and a tool such as a spanner (not shown) is screwed into the output shaft of the driver unit. It is configured so that it can be mounted using.

A notch 6 is formed on one end surface of the box bit 1, that is, an edge portion 5 of the surface on which the fitting hole 2 is formed. The notch 6 has an inclined portion 6a inclined with respect to one end surface of the box bit 1 so that the height increases in the direction of rotation of the box bit 1 when tightening the screw. The stepped portion that is also formed is formed as an arcuate portion 6b that forms an arcuate portion from the outer periphery of the box bit 1 to the fitting hole portion 2. The arcuate portion 6b is configured so as to draw an arc from the outer periphery of the box bit 1 in the direction opposite to the rotation direction of the box bit 1 when tightening the screw and gradually reach the fitting hole portion 2. There is.

The box bit 1 is used for fastening a screw having no driving hole such as a hexagonal bolt, and in using the box bit 1, the female screw portion formed on the output shaft of the driver unit is connected to the connecting portion. 3 is screwed in, and a tool such as a spanner is engaged with the position of the outer peripheral surface that is chamfered, so that the driver unit can be securely attached. After mounting on the driver unit, operate the driver unit to fit the fitting hole 2 of the box bit 1 to the head 7 of the hexagon bolt that has been temporarily tightened at the tightening position, and drive the driver unit. Securely tighten the hexagon bolt. The box bit 1 not only tightens the temporarily tightened bolts, but also, for example, a catcher (not shown) arranged coaxially with the driver unit.
It is also used when tightening the bolts held on the.

When the fitting hole 2 is fitted in the head 7 of the hexagon bolt, if the axes of the two do not coincide with each other, as shown in FIG. The surface of the end face other than the fitting hole portion 2, that is, the edge 5 of the lower end face abuts on the upper surface of the head 7 of the hexagon bolt. In such a case, the box bit 1 can be fitted with the fitting hole 2 in the head 7 of the hexagon bolt by applying rotation. That is, when the edge 5 of the box bit 1 is in contact with the top surface of the head 7 of the hexagon bolt, as shown in FIG. 4B, when the box bit 1 is rotated in the same direction as when the screw is tightened, When the stepped portion of the cutout portion 6, that is, the end point of the arcuate portion 6b contacts the side surface of the head portion 7 of the hexagon bolt and the box bit 1 is further rotated, as shown in FIGS. 4 (c) and 4 (d). , The side surface of the head 7 of the hexagon bolt moves along the notch 6 while slightly rotating, and finally, as shown in FIG.
As shown in (e), the axis is aligned with the axis of the box bit 1. At this time, since the stepped portion is formed into the arc-shaped portion 6b that forms an arc in the direction opposite to the rotation direction of the box bit 1 when tightening the screw, the movement of the hexagon bolt is extremely smooth and the head portion 7 of the hexagon bolt is Does not damage the sides.

In the present embodiment, the shape of the notch 6 is configured to be a substantially right triangle when viewed from the side of the hexagon bolt, but the shape is not limited to this, and for example, the box bit 11 It may be formed in a loop shape based on a certain point of the edge portion 5 of the end face, and the effects obtained by such a configuration are the same. Further, the inclination of the notch 6 with respect to the one end surface of the box bit 1 is not limited to only the rotating direction of the box bit 1 when tightening the screw, and for example, a shape inclined to the fitting hole 2 side, an outer peripheral side It is also possible to add a sloping shape to this, and with such a configuration, the engagement with the hexagon bolt can be further ensured.

[0012]

As described above, since the box bit of the present invention has the cutout portion at the end face where the fitting hole portion is provided, the axis line of the box bit and the axis line of the fastening part such as a hexagonal bolt coincide with each other. Even in the case of not doing so, it is possible to match them and satisfactorily engage the box bit with the hexagon bolt, etc., and it is possible to reduce defective tightening of screws and perform reliable screw tightening work. In addition, since the notch has an arcuate portion that extends from the outer periphery of the box bit to the fitting hole, the head of the fastener such as a hexagon bolt moves smoothly along this arcuate portion, so that the fastener is engaged. In this case, damage to the head can be prevented, and damage to the box bit side can also be prevented, so that the tool life can be extended.

[Brief description of drawings]

FIG. 1 is a perspective view of a box bit according to the present invention.

FIG. 2 is a front view of a box bit according to the present invention.

FIG. 3 is a plan view of a box bit according to the present invention.

FIG. 4 is an explanatory diagram of the operation of the box bit according to the present invention.

[Explanation of symbols]

 1 Box Bit 2 Fitting Hole 3 Connecting Part 4 Double Chamfer 5 Edge 6 Notch 6a Slope 6b Arc Part 7 Hexagonal Bolt Head

Claims (4)

[Claims] 1. A box bit having a fitting hole into which a screw head is fitted and a connecting portion that can be detachably connected to various screw fastening means is formed on an end face provided with the fitting hole. A box bit that has a notch formed. 2. The box bit according to claim 1, wherein the cutout portion has an inclined portion inclined with respect to the end surface. 3. The cutout portion has an arcuate portion extending from the outer peripheral side to the fitting hole portion.
Box bit described in. 4. The box bit according to claim 1, wherein the notch is formed in a loop shape whose height increases in accordance with a rotation direction at the time of screw tightening with respect to a certain point on the outer circumference of the end face.