JPH116511A - Insulation screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the insulation performance while securing the strength of a head part by separating a screw into the metallic head part and a metallic screw, and binding the head part with the screw by a resin part. SOLUTION: The insulation performance can be provided while securing the mechanical strength approximately similar to that of a totally metallic screw by separating a screw into a metallic header 1 and a metallic screw part, and binding a part between the header with the screw part by a resin part 3 by the injection molding method, etc. A nick R referred to as the knurling is formed between the header 1 and the screw part 2 to further improve the mechanical strength of a joined part. Easy handling and the mechanical strength similar to that of the metallic screw can be obtained while securing the insulation performance, and the screw can also be used as a thumb nut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an insulated screw having an insulating property in an electronic device or the like for preventing static electricity of a screw exposed on the surface of the device.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory diagram for explaining the effect of static electricity. As shown in the drawing, in a case where the printed board 21 is fixed by the screws 30 in a certain electronic device 20 installed on the mounting base 10, if the screws are made of metal, static electricity is generated as shown by a broken line in FIG. A strong magnetic field H is generated, which may adversely affect an electric circuit such as a printed board. Therefore,
Conventionally, it is general that the entire screw is simply made of resin so as to have insulation performance.

[0003]

However, it is difficult to adjust the tightening force of the screw if the screw is simply made of resin as in the prior art. That is, if the tightening force is too strong, the head (header) of the screw will be crushed, and if it is too weak, the screw will be loosened. Therefore, an object of the present invention is to provide insulation performance while securing the strength of the head.

[0004]

In order to solve this problem, according to the first aspect of the present invention, a screw is separated into a metal head and a metal screw portion, and these are joined by a resin portion. Like that. According to the first aspect of the invention, a spring mechanism can be provided on the resin portion (the second aspect of the invention). According to any one of the first and second aspects of the invention, a knurl can be formed on the resin portion.
Invention). Further, in any one of the first to third aspects of the present invention, the resin portion can be formed in a serrated shape (the invention of the fourth aspect).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view for explaining a first embodiment of the present invention. FIG. 1 (a) is a side view of a first screw, FIG. (C) is a side view of the second screw, and (d) is a front view thereof. FIG.
(E) is an enlarged partial sectional view of the first and second screws, and (f) is an enlarged front view thereof. Note that there is no essential difference between the first screw and the second screw only in the length of the screw portion. That is, the screw is separated into a metal header 1 and a metal screw portion 2, and these are joined together by a resin (resin portion) 3 using a technique such as an injection molding method.
By doing so, it is possible to provide insulation performance while securing mechanical strength substantially the same as that of a metal as a whole.

FIGS. 1 (g), 1 (h) and 1 (i) are partial cross-sectional views of the screw, in which the screw 2, resin 3 and header 1 are shown separately. This is header 1 and screw 2
A notch R called knurls is formed on the joint to further increase the mechanical strength of the joint. FIG.
(E) shows an example in which the header 1 on which the knurl R is formed and the screw portion 2 are joined by the resin portion 3.

FIGS. 2A and 2B are explanatory views for explaining a second embodiment of the present invention. FIG. 2A is a side view of a first screw, FIG. 2B is a front view thereof, and FIG. Side view of the second screw,
(D) is a front view thereof. FIG. 2E is a side view of the third screw, and FIG. 2F is a front view thereof. The first screw, the second screw, and the third screw are functionally the same except for the length and thickness of the screw portion. As is apparent from comparison with FIG. 1, a feature is that a spring mechanism 4 is provided on the resin portion 3. By applying a force so that the spring mechanism 4 can be pushed and spread on a surface to which a screw is attached. , With a function of preventing loosening.

FIGS. 3A and 3B are explanatory views for explaining a third embodiment of the present invention. FIG. 3A is a side view of a first screw, FIG. 3B is a front view thereof, and FIG. Is a side view of the second screw, and (d) is a front view thereof. FIG. 3E is a side view showing an example with a spring mechanism. The first screw and the second screw are essentially the same except for the length of the screw portion. This is achieved by forming serrations 5 in the resin portion 3 to form a jagged shape.
It can be used as a thumbscrew.
The serration m = 0.3 indicates a serration of 0.3 mm. It is to be noted that the spring mechanism described with reference to FIG. 2 can be provided to make the configuration as shown in FIG. 3E, and that the knurl R described with reference to FIG. 1 can be formed.

[0009]

According to the present invention, the same ease of handling and mechanical strength as a metal screw can be obtained while retaining insulation performance, and there is an advantage that the screw can be used as a thumb screw.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory view of a second embodiment of the present invention.

FIG. 3 is an explanatory view of a third embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining an effect of static electricity.

[Description of Signs] 1 ... Head (header), 2 ... Screw, 3 ... Resin, 4 ...
Spring mechanism, 5 ... serration, R ... knurl.

Claims (4)

[Claims] 1. An insulated screw wherein a screw is separated into a metal head and a metal screw part, and these parts are connected by a resin part. 2. The insulating screw according to claim 1, wherein a spring mechanism is provided on the resin portion. 3. The insulating screw according to claim 1, wherein a knurl is formed in the resin portion. 4. The insulating screw according to claim 1, wherein the resin portion has a serrated shape.