JPH0839983A - Fitting structure of shaft element - Google Patents

Abstract

PURPOSE:To provide the fitting structure of shaft elements preventing the inclination or dropping of an upper shaft element during a period from the putting-on of the upper shaft element to the pressure insertion thereof when the upper shaft element is put on a lower shaft element held to a vertical posture to be inserted in the lower shaft element by a pressure insertion machine. CONSTITUTION:An inward annular projection 11 is formed to the opening of the end part of a first shaft element l and an annular groove 21 is formed to the outer periphery in the vicinity of the end part of a second shaft element 2 and the second shaft element is inserted in the first shaft element under pressure to engage the annular projection and annular groove to fit the first and second shaft elements. In this fitting structure of the shaft elements, a taper part 22 is formed to the second shaft element from the annular groove thereof to the end part thereof and a temporary stop projection 23 is formed to the end part. When one shaft element is inserted in the other shaft element held to a vertical posture from above, the taper part and temporary stop projection of the second shaft element hold the annular projection of the first shaft element and the second and first shaft elements are temporarily connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fitting structure of a cylindrical cap body made of a synthetic resin for a writing instrument and a shaft body such as a tail plug.

[0002]

2. Description of the Related Art In writing instruments, hollow shaft bodies are often fitted and joined together, such as a shaft barrel and tail plug made of synthetic resin, a cap body and tail plug, or a front shaft and a rear shaft. However, in this case, for example, an inward annular projection is formed in the end opening of the shaft-shaped cap body, and an annular groove is formed in the outer periphery near the end of the tail plug, and the tail plug is press-fitted into the cap body. Using the elastic deformation, the annular projection and the annular groove are engaged to fit the tail plug to the cap body.

[0003]

By the way, in order to press-fit the tail plug into the cap body so as to elastically deform it so that the annular projection and the annular groove are engaged and the shaft bodies are joined together, it is quite difficult. Pressing force is required, so press-in is done by mechanical force. That is, one shaft is set in the press-fitting machine in a vertical posture, and the other shaft is manually put on the one shaft while being lightly inserted, and then the press-fitting head of the press-fitting machine is placed on the top shaft. Pressure is applied to the body and it is pressed.

Therefore, from when the upper shaft body is lightly inserted onto the lower shaft body set in the press-fitting machine until the press-fitting head of the press-fitting machine applies pressure to the upper shaft body to press-fit it. Meanwhile, the upper shaft body must be stationary with the axis line of the lower shaft body aligned. However, the stability of the upper shaft body is poor if the upper shaft body is lightly inserted into the lower shaft body, and the upper shaft body tilts before press fitting due to vibration of the press fitting machine. Or it may fall.

Therefore, according to the present invention, when the upper shaft body is placed on the shaft body in a vertical posture and press-fitted by a press-fitting machine, the upper shaft body tilts or falls between the mounting and the press-fitting. It is an object of the present invention to provide a fitting structure for a shaft body that does not have any problems.

[0006]

In order to achieve the above object, according to the present invention, an inwardly facing annular projection is formed in the end opening of the first shaft body and at the vicinity of the end portion of the second shaft body. An annular groove is formed on the outer circumference, the second shaft body is press-fitted into the first shaft body, and the annular body is engaged with the annular groove to fit the first shaft body and the second shaft body. In the structure, when a taper portion is formed from the annular groove of the second shaft body to the end portion and a temporary fixing projection is formed on the end portion, and one shaft body in a vertical posture is inserted with the other shaft body from above. In addition, the taper portion of the second shaft body and the temporary fixing projection hold the annular projection of the first shaft body, and
The shaft and the first shaft are temporarily fixed.

[0007]

In other words, when the other shaft body is inserted into one shaft body in the vertical posture from above, the taper portion and the temporary fixing projection of the second shaft body hold the annular projection of the first shaft body, Since the two shaft bodies and the first shaft body are temporarily fixed, when the upper shaft body is placed on the lower shaft body in the vertical posture and press-fitted by the press-fitting machine,
The upper shaft does not tilt or fall between the time it is put on and the time it is pressed in.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the embodiments shown in the drawings. In the present embodiment, as shown in FIG. 1, the first shaft body 1 is a cap body of a writing instrument and the second shaft body 2 is a tail plug, but the first shaft body and the second shaft body are shafts. It may be a cylinder and a tail plug, or a front shaft and a rear shaft.

As shown in FIG. 2 (A), an annular groove 21 is formed on the outer peripheral surface near the end of the second shaft body 2 made of synthetic resin.
Are formed. Then, a notch 24 is provided from the annular groove 21 to the end portion so as to be easily elastically deformed.
Further, a taper portion 22 is formed on the end side of the annular groove 21, and a temporary fixing projection 22 that is a small annular projection is formed on the end portion.
Are formed. On the other hand, the first shaft body 1 is also made of synthetic resin, and an inwardly facing annular projection 11 is formed at the end opening.

When the first shaft body 1 and the second shaft body 2 are press-fitted to each other using the press-fitting machine, the large second shaft body 1 is set in a vertical posture and set in a press-fitting machine (not shown). Then, the worker gently pushes the second shaft body 2 into the opening of the first shaft body 1.
As a result, as shown in FIG. 2 (B), the annular projection 11 of the first shaft body 1 gets over the temporary fixing projection 22, and the annular projection 11
The corners of the abutting contact the tapered portion 22. Since the temporary fixing projection 22 is a small annular projection, the annular projection 11 gets over the temporary fixing projection 22 only by lightly pushing it in. Since the annular projection 11 that has passed over the temporary fixing projection 22 is held by the temporary fixing projection 22 and the taper portion 22 and temporarily fixed, the second shaft body 2 may tilt or fall even if the operator releases his hand. There is no. Subsequently, when the press-fitting head of the press-fitting machine descends and pushes in the second shaft body 2, the end portion of the second shaft body 2 elastically deforms, and as shown in FIG.
1 and the press-fitting of the first shaft body 1 and the second shaft body 2 is completed.

[0011]

As described above, the fitting structure of the shaft body of the present invention is formed on the second shaft body when the other shaft body is vertically inserted into the one shaft body. Since the taper portion and the temporary fixing projection hold the inward annular projection of the first shaft body so that the second shaft body and the first shaft body are temporarily fixed, the upper shaft body is held in a vertical posture. When it is placed on the shaft body and press-fitted by the press-fitting machine, the upper shaft body does not tilt or drop between the time of mounting and the press-fitting.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a press-fitting process.

[Explanation of symbols]

 1 1st shaft body 11 Inward annular projection 2 2nd shaft body 2 21 Annular groove 22 Tapered part 23 Temporary fixing projection

Claims (1)

[Claims] 1. An inwardly directed annular projection is formed at an end opening of the first shaft body, and an annular groove is formed at an outer periphery of the second shaft body in the vicinity of the end portion thereof. In a fitting structure of a shaft body, which is press-fitted into a body and engages the annular projection and the annular groove to fit the first shaft body and the second shaft body, a taper from the annular groove of the second shaft body to an end portion. The second shaft when the second shaft body or the first shaft body is inserted from above into the first shaft body or the second shaft body in the vertical posture while forming the portion and the temporary fixing projection at the end. A fitting structure for a shaft body, wherein a tapered portion of the body and a temporary fixing projection hold an annular projection of the first shaft body, and the second shaft body and the first shaft body are temporarily fixed.