JPH08216296A - Method of forming paper feeding roller - Google Patents

Abstract

PURPOSE: To improve product precision and reduce costs by forming a shaft and a roller integrally by two-color molding. CONSTITUTION: A roller hold portion 31a of a shaft 31 is formed together with a shaft portion 31c in primary molding. The roller hold portion 31a has a larger diameter than the shaft portion 31c, and has a ring-like groove 31b. After the first process, a roller 32 is formed on the outer peripheral portion of the roller hold portion 31a and thus integrated with the roller hold portion 31a in secondary molding. Cavity slides 9a, 9b for the primary molding and secondary molding are provided on the fixed part of the parting face of the die, and core slides 10 for the primary molding and secondary molding are provided on the movable part, in such an arrangement than the slides for the primary molding and secondary molding are respectively point-symmetrical about the rotational axis X. By rotating the movable part, the primary product supported by the core slide 10 is transferred to the secondary die part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a paper feed roller, which is composed of a shaft made of a hard material and a roller made of a soft material, which is used in, for example, office equipment.

[0002]

2. Description of the Related Art In an office machine having a paper feeding mechanism such as a copying machine, a printing machine, a fax machine and a printer, a paper feeding roller 40 having a soft roller 42 fixed to a shaft 41 as shown in FIG. A mechanism is used to sandwich and feed the paper between the rollers 42 and 42.

Conventionally, in manufacturing such a paper feed roller 40, a shaft 41 and a roller 42 are separately molded, and the roller 42 is press-fitted into the shaft 41.

When the roller 42 is separately molded and press-fitted onto the shaft 41 as described above, a problem may occur in press-fitting accuracy, and the number of parts is large, resulting in high cost.

[0005]

SUMMARY OF THE INVENTION The present invention uses a two-color molding method to integrally form a shaft portion of a paper feed roller and a roller.
For the purpose of proposing a method for forming a paper feed roller, which is formed by a machine of a table, improves the press-fitting accuracy of the roller, prevents the roller from slipping out of the shaft, and from falling out, and reduces the number of parts. There is.

[0006]

According to the present invention, in a method for forming a paper feed roller composed of a shaft made of a hard material and a roller made of a soft material, a ring is formed with a roller hold portion of the shaft having a diameter larger than that of the shaft portion. A groove is provided in the shape of a roller to perform primary molding integrally with the shaft portion, and the roller is integrally molded to the outer peripheral portion of the primary-molded roller holding portion to perform secondary molding.

Further, in the present invention, at the time of the above-mentioned primary and secondary molding, a cavitity slide is provided on the fixed side of the parting surface which is divided into a fixed side and a movable side of the mold, and a core slide is provided on the movable side. The bisti slide has two different shapes. The primary molding product and the secondary molding product are respectively arranged at positions symmetrical with respect to the axis of rotation, and the movable side is rotated and held by the core slide. Is transferred to the secondary side for molding.

[0008]

According to the method of molding the paper feed roller constructed as described above, the soft material roller is firmly and accurately integrated by the ring-shaped groove to the hard material shaft.
Further, it can be easily manufactured by using a known two-color molding die.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

In order to explain the present invention in an easy-to-understand manner, the paper feed roller 30 molded according to the present invention will be described assuming that two rollers 32 are used as shown in FIGS. 8 and 9. As shown in FIGS. 1 and 2, the roller 32 has a shaft 31.
The roller hold portion 31a of the shaft 31 which is provided near both ends of the shaft 31 and which is primarily formed as described later has a ring-shaped concave groove 31b having a diameter larger than that of the shaft portion 31c, and has a soft outside. The roller 32 is molded by secondary molding as described later.

FIG. 3 shows an outline of a mold for carrying out the present invention. The mold is the part B on the secondary side shown at the top and bottom of FIG.
And a primary side portion A, the molding die is composed of a core slide 10 and cavitity slides 9a and 9b,
The primary molding injection port 17 is provided in the center of the mold, and the secondary molding injection port 18 is provided so as to inject from the upper surface. The core slide 10 side is movable, and the primary molded product 28 is sent to the secondary molding die by rotating 180 ° about the rotation axis X and the secondary molded product 27 is molded.

Details of the mold are shown in FIGS.

A parting surface P is provided between the fixed side mold plate 3 and the movable side mold plate 4, and is divided into a fixed side F and a movable side M. The primary molded product 28 and the secondary molded product 27 have their axes. The mold is arranged point-symmetrically with respect to the rotation axis X with the center line aligned with the parting surface P. That is, the core slide 10 that slides in the direction perpendicular to the rotation axis X is located at the center of the movable mold plate 4 side.
The cavitity slides 9a and 9b, which slide on both sides of the core slide 10 in parallel with each other and form the roller portion, are arranged on the fixed-side mold plate 3 side, and the primary molding and the secondary molding are arranged at point symmetrical positions, respectively. It is set up. The core slide 10 has the same shape in both the primary and secondary, and the cavitity slides 9a and 9b.
Has a different shape from the primary 9a (the shape of the roller hold portion 31a) and the secondary 9b (the shape of the roller 32). Then, in order to operate them separately, the angular slides 13 are obliquely passed from the fixed side F to the cavitity slides 9a and 9b, and the core slide cam 15 is slidable from the movable side M with respect to the core slide 10. Is provided.

Locking blocks 12 and 14 for locking the cavitity slides 9a and 9b are locking pins 11 for locking the core slide 10.
Are provided on the fixed side F, respectively.

The primary molding injection port 17 is provided at the center of the rotation axis X of the fixed side mounting plate 1, and passes through the fixed side mounting plate 1 and the runner stripper plate 2, the primary sprue 19, the runner stripper plate 2 and the fixed side mold. It communicates with the primary pin gate 21 through the primary runner 25 between the plate 3 and the primary sprue 20 in the stationary mold plate 3.

The secondary molding injection port 18 is provided on the upper surface of the mold, and the secondary runner 26, which is divided into two between the runner stripper plate 2 and the fixed side mold plate 3, and the secondary mold run through the fixed side mold plate 3. The sprue 22 and the secondary runner 23 on the parting surface P communicate with the secondary submarine gate 24.

Next, an example of the method of the present invention will be described. In the mold clamped state, the core slide 10 and the cavitity slides 9a and 9b are closed to form a molding die, and primary molding and secondary molding are simultaneously performed.

On the primary side, the primary molding material is injected from the primary molding injection port 17 and is injected from the primary pin gate 21 through 19 → 25 → 20 to form a primary molded product 28. Next, as shown in FIG. 7, the mold is opened, the fixed side F and the movable side M are separated on the parting surface P, and the cavitity slide 9a is opened by the angular pin 13, while
The core slide cam pin 15 does not operate, the core slide 10 does not move, and the primary molded product 28 is held.

In this way, the movable side M rotates 180 °, and the primary molded product 28 moves to the secondary molding position. When the mold is clamped, the secondary cavitity slide 9b is closed by the angular pin 13. The secondary molding material is injected from the secondary molding injection port 18, is injected from the secondary submarine gate 24 through 26 → 22 → 23, and the secondary molding is performed.

When the mold is opened, the cavitity slide 9b is opened by the angular pin 13 and the ejector plate B7 is operated to open the core slide 10 by the core slide cam pin 15. Further, the ejector plate B7 pushes the ejector plate A6, and the molded product 27 is projected by the ejector pin 16.

The present invention is not limited to the paper feed roller using two rollers as described above, but can be applied to a paper feed roller using a larger number of rollers.

It is also possible to add a gear or the like and perform the three-color molding method.

[0023]

As described above, according to the present invention, since the roller and the shaft are integrally formed by one machine, the number of parts is reduced, the roller press-fitting step is not required, and the roller mounting position is reduced. Accuracy is improved, and there is no deviation or slipping out, and quality improvement and cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a roller portion according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the shaft of FIG.

FIG. 3 is an explanatory view of a mold for carrying out the present invention.

FIG. 4 is a sectional view showing a mold for carrying out the present invention.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

6 is a sectional view taken along line CC of FIG.

FIG. 7 is a cross-sectional view showing the mold open state of FIG.

FIG. 8 is a perspective view showing a paper feed roller used in the description of the embodiment.

9 is a side view of FIG.

FIG. 10 is a perspective view showing the shape of a general paper feed roller.

[Explanation of symbols]

 1 ・ ・ ・ ・ ・ ・ Fixed side mounting plate 2 ・ ・ ・ ・ ・ ・ Ranna stripper plate 3 ・ ・ ・ ・ ・ ・ Fixed side mold plate 4 ・ ・ ・ ・ ・ ・ Movable side mold Plates 6 and 7 Ejector plates 9a and 9b Cavitity slides 10 Core slides 11 Locking pins 12 ··· Locking block A 13 ···· Angular pin 14 ···· Locking block B 15 ··· · Core slide cam pin 16 ··· Ejector Pin 17 ... Primary molding injection port 18 ... Secondary molding injection port 19, 20 Primary sprue 21 Primary pin gate 22・ ・ ・ ・ ・ ・ ・ ・ Secondary sprue 23 ・ ・ ・ ・ ・ ・ ・ ・ Secondary runner 24・ ・ ・ ・ ・ ・ ・ ・ Secondary submarine gate 25 ・ ・ ・ ・ ・ ・ Primary runner 26 ・ ・ ・ ・ ・ ・ ・ ・ Secondary runner 27 ・ ・ ・ ・ ・ ・ ・ ・ Secondary molded product 28 ・・ ・ ・ Primary molded product 30, 40 ・ ・ ・ ・ ・ Paper feed roller 31, 41 ・ ・ ・ ・ ・ Shaft 31a ・ ・ ・ ・ ・ ・ Roller hold part 31b ・ ・ ・ ・ ・Groove 31c .... Shaft 32, 42 .. Roller X ..... Rotating shaft P ..... Parting surface F ..・ ・ ・ ・ ・ Fixed side M ・ ・ ・ ・ ・ ・ ・ ・ Movable side

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // B65H 5/06 B65H 5/06 B 27/00 27/00 B

Claims (2)

[Claims] 1. A method for forming a paper feed roller comprising a shaft made of a hard material and a roller made of a soft material, wherein a roller hold portion of the shaft has a diameter larger than that of the shaft portion and a ring-shaped groove is provided to form the shaft portion. A method for forming a paper feed roller, which comprises integrally forming a primary roller, and integrally forming a roller on an outer peripheral portion of a roller holder that has been primary molded. 2. In the primary and secondary molding, a cavitity slide is provided on a fixed side of a parting surface which is divided into a fixed side and a movable side of a mold, and a core slide is provided on the movable side. There are different types of shapes.The primary molding and the secondary molding are arranged at point-symmetrical positions on the rotation axis, and the primary molding that rotates the movable side and is held by the core slide is the secondary side. The method for molding a paper feed roller according to claim 1, wherein the molding is carried out by molding.