JPH085829Y2 - Threaded structure of synthetic resin pipe body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a structure in which pipes made of synthetic resin having different hardness are screwed together. Here, a concrete example of the pipe body is a shaft body such as a writing instrument.

(Prior Art) Conventionally, a screwing structure of a synthetic resin pipe body is made up of a pipe body in which a male screw portion is formed on the outer wall of the small diameter opening and a pipe body in which a female screw portion is formed on the inner wall of the large diameter hole portion. When screwing, positioning is performed by bringing the opening end of the pipe body having the female screw portion into contact with the end of the small diameter portion of the opening of the pipe body having the male screw portion.

(Problems to be solved by the invention) The screwing loosens as something happens. A concrete explanation will be given by taking a shaft of a writing instrument as an example. FIG. 3 shows a very general structure as an oil-based ballpoint pen. They are screwed together. When the ballpoint nib 3 that holds the front shaft 1 or the rear shaft 2 and projects from the tip of the front shaft 1 is used for writing, the screwing of the front shaft 1 and the rear shaft 2 gradually becomes loose and it becomes difficult to write. . Reference numeral 4 is an ink tank body.

(Means for Solving the Problems) The present invention has a structure in which synthetic resin pipe bodies having different hardness are screwed together, and is a relatively soft pipe body (A) having a male screw portion on the outer wall of the opening small diameter portion. ) And a relatively hard pipe body (B) having a female screw portion on the inner wall of the opening large-diameter hole portion, the opening end of the pipe body (B) contacts the end portion of the opening small-diameter portion of the pipe body (A). The length of the opening small diameter portion of the pipe body (A) is set so that the opening end portion of the pipe body (A) abuts on the back end portion of the opening large diameter hole portion of the pipe body (B) while contacting. The gist is a threaded structure of a synthetic resin pipe body which is longer than the length of the opening large diameter hole portion of).

(Embodiment) Of course, the present invention can be applied as a screwing structure of a pipe body other than the shaft body of the ballpoint pen, but in comparison with the above,
An example of an oil-based ballpoint pen is shown in FIG. In the following, the same reference numerals are used for the basically same parts as described above.

In relation to the above, the front shaft 1 having a female screw portion and the rear shaft 2 having a male screw portion are screwed with each other, and the opening end portion of the front shaft 1 is attached to the end portion of the opening small diameter portion of the rear shaft 2. Are similar in that they are abutted and positioned. However, in the present example, the open end of the rear shaft 2 also comes into contact with the rear end of the large-diameter hole portion of the front shaft 1. Further, both the front shaft 1 and the rear shaft 2 are made of synthetic resin, but the rear shaft 2 is relatively softer. That is, in this example, the front shaft 1 corresponds to the pipe body (B), and the rear shaft 2 corresponds to the pipe body (A).

The front shaft 1 and the rear shaft 2 satisfy such a relationship because the length of the small opening portion of the rear shaft 2 is made longer than the length of the large opening hole portion of the front shaft 1. Even after the screwing progresses until the opening end of the rear shaft 2 contacts the rear end of the large diameter rear part of the front shaft 1, the opening end of the front shaft 1 is attached to the end part of the small opening part of the rear shaft 2. Is a relationship formed by advancing the screwing until the abut.

At this time, the opening small diameter portion of the rear shaft 2 is deformed, but in the figure, this deformation is utilized to prevent lateral shake of the ink tank main body 4.

Here, referring to the materials of the front shaft 1 and the rear shaft 2, the front shaft 1 and the rear shaft 2 are formed of a commonly used molding resin. Specifically, polyethylene,
Examples thereof include polypropylene, polyvinyl chloride, polystyrene, polycarbonate, poly (meth) acrylic acid ester, melamine resin, and urea resin. The relatively soft one is selected as the rear shaft 2 and the hard one is selected as the front shaft 1. Used in combination.

The attached FIG. 2 shows an example of a modification. In this example, the material relationship between the front shaft 1 and the rear shaft 2 in the preoperative first embodiment is reversed, and in the front shaft 1 of this example, the front shaft 1 is the pipe body (A). Further, the rear shaft 2 corresponds to the pipe body (B).

(Effect of device) It is possible to suppress loosening of the screwing relationship. Also, the pipe body (A)
Since the deformation of (1) appears on the inner surface, it does not adversely affect the appearance.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view showing a modified example, and FIG. 3 is a sectional view showing a conventional example. 1 ... Front axis, 2 ... Rear axis, 3 ... Ballpoint pen tip, 4 ...
Ink tank body.

Claims (1)

[Scope of utility model registration request] 1. A relatively soft pipe body (A) having a male screw portion on the outer wall of the opening small diameter portion and an inner wall of the opening large diameter hole portion having a structure in which synthetic resin pipe bodies having different hardness are screwed together. And a relatively hard pipe body (B) having a female screw portion at the opening end portion of the pipe body (B) abutting on the end portion of the small diameter opening portion of the pipe body (A), and the pipe body (A). The length of the opening small diameter portion of the pipe body (A) is set so that the opening end portion of the pipe body (B) contacts the rear end portion of the opening large diameter hole portion of the pipe body (B). Threaded structure of synthetic resin pipe that is longer than the length.