JPH0825242A - Screw fastening tool - Google Patents

Abstract

PURPOSE:To provide a screw fastening tool strongly attracting and holding a screw. CONSTITUTION:A screw driver bit 1 is provided with a coupling section 4 coupled with the driving hole of a screw head section and a main body section 2 connected to it, the main body section 2 is made of a nonmagnetic substance, and the coupling section 4 is made of a magnetic substance. The main body section 2 and coupling section 4 are splittably formed, the main body section 2 is provided with a storage hole 2b located to face the coupling section 4, and a permanent magnet 3 is stored in the storage hole 2b. Accordingly, the screw driver bit 1 stores the permanent magnet 3 in the main body section 2 made of a nonmagnetic substance, and the coupling section 4 made of a magnetic substance is provided in front of it. The loss of the magnetic flux at portions other than the coupling section 4 can be suppressed to the minimum, the coupling section 4 can be strongly magnetized, and a screw can be strongly attracted and held by the coupling section 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw tightening tool such as a driver bit, the tip of which is shaped to engage with a drive hole of a screw head. Regarding tightening tools.

[0002]

2. Description of the Related Art Conventionally, a driver bit has been widely known as a screw tightening tool for tightening screws. The tip of this driver bit is shaped so as to engage with the drive hole of the head of the desired screw, and the screw is tightened by engaging it with the drive hole of the screw and rotating the driver bit. There are various kinds of such driver bits depending on the use, and various improvements have been made especially in respect of holding the screw by the driver bit itself, and many screw holding type driver bits have been put to practical use. Of these, a representative one is a magnetized engaging portion at the tip of the driver bit, and such a driver bit is an engaging portion that engages with a screw head at the tip of the driver bit 50 as shown in FIG. It is configured to magnetize 51 to hold the screw.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the driver bit 50 in which the engaging portion 51 is magnetized, the engaging portion 51 is formed of a permanent magnet material when the engaging portion 51 is magnetized. In general, by using such a permanent magnet material for the engaging portion 51 of the driver bit 50, it is possible to maintain the magnetic force of the engaging portion 51 for a long period of time, but on the other hand, if the magnetic force is increased, it becomes brittle. When the engaging portion 51 of the driver bit 50 is made of a permanent magnet material, the magnetic force becomes weak and it becomes impossible to strongly attract and hold the screw. .

The present invention has been made in view of the above problems, and an object of the present invention is to provide a screw tightening tool that strongly attracts and holds screws.

[0005]

In order to achieve the above object, there is provided a screw tightening tool having an engaging portion which engages with a drive hole of a screw head and a main body portion which is continuous with the engaging portion. Molded with a non-magnetic material, the engaging portion is molded with a magnetic material, the main body portion and the engaging portion are configured to be separable, and the main body portion is provided with a storage hole facing the engaging portion, A magnetizing member is built in here. A permanent magnet is suitable as the magnetizing member in this screw tightening tool.

[0006]

In the screw tightening tool having the above-mentioned structure, the engaging portion made of a magnetic material is applied, and by magnetizing this with a permanent magnet, it becomes possible to obtain an engaging portion having a strong magnetic force, and Can be kept for a long time. Moreover, since the periphery of the permanent magnet is covered by the main body which is a non-magnetic material, the magnetic force does not decrease due to the leakage of the magnetic flux of the permanent magnet to the main body, and the engaging portion is further strongly magnetized. be able to.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 1 denotes a screw tightening tool, which is a driver bit in which an engaging portion that engages with a driving hole of a screw head is formed at the tip of a solid rod-shaped member. In addition to such driver bits, hexagonal wrench corresponding to hexagon socket head bolt, socket tool corresponding to tightening hexagon bolt or hexagon nut are known as screw tightening tools.
In the present embodiment, a driver bit will be taken up as a typical example to describe the configuration, operation and the like. Also,
It is extremely easy to apply the configuration described below to the screw tightening tool described above and other screw tightening tools.

Driver bit 1 which is the screw tightening tool
(Hereinafter, the screw tightening tool will be described as a driver bit 1.) has a main body 2 made of a solid rod-shaped member, and the rear part thereof is formed into a hexagonal shape, in which a driver bit holding device such as a screw tightener is held. A groove into which a holding member such as a steel ball provided in a portion (not shown) is fitted is cut. A screw hole 2a is formed at the tip of the main body 2, and a bottomed storage hole 2b for storing a magnetizing member described later is provided further inside the screw hole 2a. The main body 2 is formed of stainless steel SUS304, which is a non-magnetic material, and its surface is hardened by ion nitriding to obtain hardness.

A cylindrical permanent magnet 3 as a magnetizing member is housed in the housing hole of the main body 2, and a screw hole 2a is provided in front of the housing hole 2b in which the permanent magnet 3 is housed.
The engaging portion 4 shown in FIG. The engaging portion 4 is a screw portion 4a screwed into the screw hole of the main body portion 2.
And a bit portion 4b that engages with the drive hole of the screw head. The bit portion 4b has a substantially conical shape that is gradually sharpened toward the tip, and divides the outer circumference into four equal parts along the inclined surface. The curved recessed portion is formed into a cross shape that engages with the cross shaped drive hole of the screw head.

When the threaded portion 4a of the engaging portion 4 is completely screwed into the threaded hole 2a of the body portion 2 to fix the engaging portion 4 and the body portion 2 to each other, the rear end surface of the threaded portion 4a is Abutting on the front end surface of the permanent magnet 3 housed in the housing hole 2b,
The permanent magnet 3 is configured to be securely fixed in the storage hole 2b. This engaging portion is widely used as a material for a driver bit, and is made of tool steel which is a magnetic material, and has a characteristic of being easily magnetized.

The driver bit 1 having the above-mentioned structure is provided with the engaging portion 4 made of tool steel which is a magnetic material having a high magnetic attraction force, and the permanent magnet 3 magnetizes the engaging portion 4 so that the engaging portion 4 has a strong magnetic force. Can be obtained, and the magnetic force can be maintained for a long time. Moreover, the permanent magnet 3
Around non-magnetic stainless steel (SUS304)
The permanent magnet 3 is covered by the main body 2 composed of
The magnetic flux of 1 does not cause a decrease in magnetic force caused by leakage to the main body 2, and the engaging portion 4 can be magnetized more strongly. Further, since the permanent magnet 3 is built in the main body portion 2, the impact due to the driver bit 1 dropping or colliding does not directly act on the permanent magnet 3,
It is possible to protect the permanent magnet 3 which is basically fragile and is liable to be broken such as cracked or chipped.

As for the shape of the engaging portion 4 in the driver bit 1, as shown in FIG. 3B, the tip is formed into a curved surface whose upper surface coincides with the upper surface of the screw head, and the screw is inserted from the center position thereof. There is no problem even if the shape is formed so that the tip of the bit portion 4b projects by the depth of the driving hole. As for the magnetizing member, not only a permanent magnet but also an electromagnet that uses a magnetic field generated by energizing this coil, for example, by providing a coil receiver around the outer periphery of the driver bit and winding the coil in multiple turns. Can also be considered.

[0013]

As described above in detail, the driver bit, which is the screw tightening tool of the present invention, magnetizes the driver bit by the magnetic force of the permanent magnet and attracts and holds the screw at the tip of the driver bit by the magnetic force. Since the permanent magnet is housed in the main body made of a non-magnetic material and the engaging portion made of a magnetic material is provided in front of this, it is possible to minimize the loss of magnetic flux other than the engaging portion. As a result, the engaging portion can be strongly magnetized, and the screw can be strongly attracted and held to the engaging portion.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of an embodiment of a screw tightening tool according to the present invention.

FIG. 2 is a front view of an embodiment of the screw tightening tool according to the present invention.

FIG. 3 is a perspective view of an engaging portion of the screw tightening tool according to the present invention.

FIG. 4 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1 Driver Bit 2 Main Body 2a Screw Hole 2b Storage Hole 3 Permanent Magnet 4 Engagement Part 4a Screw Part 4b Bit Part

Claims (2)

[Claims] 1. A screw tightening tool having an engaging portion that engages with a drive hole of a screw head and a main body portion that is continuous with the engaging portion, wherein the main body portion is formed of a non-magnetic material, and the engaging portion is magnetic. In addition to being formed by a body, the main body portion and the engaging portion are configured to be separable, the main body portion is provided with a storage hole facing the engaging portion, and a magnetizing member is incorporated therein. Screw tightening tool. 2. The screw tightening tool according to claim 1, wherein the magnetizing member is a permanent magnet.