JP2002327726A - Cap nut and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap nut capable of easily and surely positioning a head portion on the top surface of a nut portion and effectively, integrally forming, and obtaining reduction in cost and improvement of reliability. SOLUTION: In the cap nut consisting of the nut portion 1 and head portion 4, a bulged portion 6 for guiding having the outer diameter s slightly smaller than the least inner diameter t of the nut portion 1 and extended downward with a designated height h is formed in the center of the undersurface 5 of the head portion 4. A ring-shaped bulged portion 7 for welding somewhat extended downward is formed in an outer peripheral part of the bulged portion 6 for guiding. The bulged portion 6 for guiding of the head portion 4 is inserted into an opening 2 of a screw hole of the nut portion 1, and the bulged portion 7 for welding is integrally formed by means of welding with an top surface 3 of the nut portion 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a cap nut used for protecting a tip of a bolt to enhance safety.

[0002]

2. Description of the Related Art As a conventional cap nut, as shown in FIG. 5, a cylindrical nut portion a having a female screw therein and a head c having a driver groove d on the upper surface are welded. Are widely known.

As shown in FIG. 6, a lower bottom surface e of a head c constituting the cap nut is formed in a flat shape. It is welded to the upper surface b and is integrally formed.

[0004]

[Problems to be solved by the invention]

[0005] As shown in FIG. 6, the conventional cap nut is used to weld the head c to the nut portion a when the head c is welded.
Must be accurately positioned on the upper surface b of the nut portion a so that the center of the nut portion a coincides with the center of the nut portion a. However, the welding work while positioning is very troublesome, and the working efficiency is significantly deteriorated. I have. For this reason, there is a tendency that the head c and the nut portion a are displaced to increase the defective rate, which causes a problem in quality.

Therefore, an object of the present invention is to make it possible to position the head extremely easily and reliably on the upper surface of the nut portion and to efficiently form the head and the nut portion integrally, thereby reducing the cost and reducing the reliability. An object of the present invention is to provide a cap nut having improved performance and a rational manufacturing method thereof.

[0007]

According to a first aspect of the present invention, there is provided a cap nut comprising a nut portion and a head portion, wherein a lower surface of the head portion is provided. 5, a guide bulging portion 6 having a predetermined height h protruding downward with an outer dimension s slightly smaller than the minimum inner dimension t of the nut portion 1 is formed, and the guide bulging portion 6 is formed. A ring-shaped welding swelling portion 7 slightly protruding downward is formed at the outer peripheral position of the nut 6, and the guide swelling portion 6 of the head 4 is fitted into the screw hole opening 2 of the nut 1. The swelling portion 7 for welding is welded to the upper surface 3 of the nut portion 1 to be integrally formed.

According to a second aspect of the present invention, the height h of the guide bulging portion 6 of the head 4 is substantially equal to the height of the welding bulging portion 7. .

According to a third aspect of the present invention, a driver groove 9 is formed in the upper surface 8 of the head 4.

A cap nut according to a fourth aspect is characterized in that the outer periphery of the head 4 is formed in a rectangular shape.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a cap nut having the following configuration. a) First, in the center of the lower surface 5 of the head portion 4 of the cap nut formed of the nut portion 1 and the head portion 4, a cylindrical shape having an outer shape s whose overall shape is slightly smaller than the minimum inner size t of the nut portion 1. The guide bulge 6 having a predetermined height h and protruding downward is formed. b) Next, at the outer peripheral position of the guide bulging portion 6 of the head 4, a welding bulging portion 7 having an overall shape of a ring and sharply projecting slightly downward is formed. c) Therefore, after the guide bulging portion 6 of the head 4 is inserted and positioned while guiding the bulging portion 6 of the head portion 4 into the screw hole opening 2 of the nut portion 1, the bulging portion 7 for welding is attached to the upper surface portion 3 of the nut portion 1. And the cap nut is completed.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a cap nut according to the present invention;

As shown in FIG. 4, the present embodiment is embodied in a cap nut in which a nut 1 and a head 4 are integrally formed.

FIGS. 1A and 1B show the structure of the head 4. In the center of the lower surface 5 of the head 4, as shown in FIG.
, A column-shaped bulging portion 6 for guide having a predetermined height h protruding downward with an outer dimension s slightly smaller than the minimum inner dimension t. Further, at the outer peripheral position of the guide bulging portion 6, a ring-shaped welding bulging portion 7 slightly protruding downward.
Are formed (FIG. 1B).

On the other hand, as shown in FIG. 3, the nut portion 1 is formed in a cylindrical shape having an internal thread.
The guide bulging portion 6 of the head 4 is inserted into the screw hole opening 2 of the nut portion 1, and the welding bulging portion 7 is welded to the upper surface 3 of the nut portion 1 to be integrally formed. (FIG. 4).

As shown in FIG. 2, the height 4 of the guide bulge 6 of the head 4 is cut so as to be substantially the same as the height of the bulge 7 for welding. The embodiment is also suitably implemented (claim 2).

Further, in the cap nut of the present embodiment,
A driver groove 9 is formed in the upper surface 8 of the head 4 (claim 3). However, even if the driver groove 9 is not formed on the upper surface 8 of the head 4, the outer periphery of the head 4 may be formed in a square shape so that a monkey wrench can be used, for example, as in the invention of claim 4. Good (not shown).

Next, an embodiment of a method for manufacturing a cap nut according to the present invention will be described with reference to the drawings.

In the center of the lower surface 5 of the cap nut head 4, a bulging portion 6 for guiding and a bulging portion 7 for welding are integrally formed. As described above, the guide bulging portion 6 has a cylindrical shape having an outer dimension s slightly smaller than the minimum inner dimension t of the nut portion 1 and has a predetermined height h and is formed by projecting downward. . In addition, the welding bulging portion 7 is formed in a ring shape as a whole at an outer peripheral position of the guide bulging portion 6, and is formed so as to be sharply tapered downward and slightly protruded (FIGS. 1 and 1). 2).

Therefore, when welding the head 4 and the nut 1 (FIG. 3), the guide bulging portion 6 of the head 4 is fitted and inserted into the screw hole opening 2 of the nut 1 while being guided. The head 4 can be easily and accurately positioned simply and reliably, and no displacement of the head 4 occurs at the position once determined. In such a state, the welding bulging portion 7 is welded to the upper surface portion 3 of the nut portion 1 to be integrally formed, whereby a high-quality cap nut can be manufactured smoothly while preventing displacement. 4).

The shape, size, material, and the like of the cap nut head 4 and the nut portion 1 are not limited to the above-described embodiments, but can be implemented in various modes.

[0022]

The cap nut according to the first aspect of the present invention has a guide bulging portion having a predetermined height protruding downward at an outer dimension slightly smaller than the minimum inner dimension of the nut portion at the center of the lower surface of the head. A ring-shaped welding swelling part which is formed and slightly protrudes downward at the outer peripheral position of the guide swelling part is formed, and the guide swelling part of the head is inserted into the screw hole opening of the nut part. In this state, the welding swelling portion is simply and reliably welded to the upper surface of the nut portion, so that higher quality and lower cost can be achieved as compared with the conventional product, which contributes to improvement in reliability.

According to a second aspect of the present invention,
Since the height of the bulging portion for guiding the head is formed to be substantially the same as the height of the bulging portion for welding, the manufacturing cost of the head is reduced and the workability is improved.

According to a third aspect of the present invention, there is provided a cap nut,
Since the driver groove is formed on the upper surface of the head, after the head is accurately welded to the nut portion, there is no hindrance at the time of using the driver, which contributes to an improvement in working efficiency.

The cap nut according to the fourth aspect of the present invention
Since the outer periphery of the head is formed in a rectangular shape, the head is accurately welded to the nut portion, and there is no problem when using a tool such as a monkey wrench, which contributes to an improvement in working efficiency.

According to the method for manufacturing a cap nut according to the fifth aspect of the invention, when welding the head and the nut portion, the guide bulge portion of the head portion is guided smoothly to the screw hole opening of the nut portion. The head can be easily and reliably set in an appropriate position, and the swelling part for welding and the upper surface of the nut part are welded together without any deviation of the head at the determined position. By being integrally formed, a high-quality cap nut can be manufactured smoothly while preventing displacement, which greatly contributes to improvement of working efficiency, reduction of manufacturing cost, and improvement of reliability.

[Brief description of the drawings]

FIGS. 1A and 1B are a cross-sectional view and a rear view showing a head portion of a cap nut.

FIG. 2 is a cross-sectional view showing a different embodiment of a cap nut head.

FIG. 3 is a cross-sectional view showing a procedure for welding a cap nut head and a nut portion.

FIG. 4 is a sectional view showing a completed state of the cap nut.

FIGS. 5A and 5B are a plan view and a front view showing a conventional cap nut.

FIG. 6 is a front view showing a conventional procedure for welding a cap nut head and a nut portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nut part 2 Screw hole opening 3 Upper surface 4 Head 5 Lower surface 6 Projecting portion for welding 7 Spreading portion for welding 8 Top surface 9 Driver groove t Inside dimension s Outside dimension h Height

Claims (5)

[Claims] 1. A cap nut comprising a nut portion and a head, a guide expansion having a predetermined height protruding downward at an outer dimension slightly smaller than a minimum inner dimension of the nut portion at a center of a lower surface of the head. A projecting portion is formed, and a ring-shaped welding swelling portion slightly protruding downward is formed at an outer peripheral position of the guide swelling portion, and the guide swelling portion of the head is a nut portion. Wherein the swelling portion for welding is welded to the upper surface of the nut portion to be integrally formed. 2. The cap nut according to claim 1, wherein the height of the bulging portion for guiding the head is substantially the same as the height of the bulging portion for welding. 3. The cap nut according to claim 1, wherein a driver groove is formed on an upper surface of the head. 4. The cap nut according to claim 1, wherein the outer periphery of the head is formed in a square shape. 5. A cap having a nut portion and a head portion, the center portion of the lower surface of the head portion having a cylindrical shape having an outer size slightly smaller than a minimum inner size of the nut portion, and having a predetermined height. B) forming a bulging portion for a guide that protrudes downward, and b) a welding bulge that has a ring-like overall shape and is slightly protruded sharply downward at an outer circumferential position of the bulging portion for guide. C) after inserting and positioning the guide bulging portion of the head while guiding it into the screw hole opening of the nut portion, welding the bulging portion for welding to the upper surface of the nut portion. A method for producing a cap nut, characterized by being integrally formed.