JPH0599278A - Connecting pin for chain and chain - Google Patents

Abstract

PURPOSE:To provide a connecting pin for a chain which can facilitate a pull-out work for a connecting pin and has large shearing strength and large strength for bending moment and to provide a chain. CONSTITUTION:A circular shell 3 is projected from the front end side of a drum portion 2 toward the front side. A shoulder portion 3a increased in its diameter than the rear end portion of the circular shell is formed on the outer surface of the middle portion of the circular shell, and the outer surface of the front end portion of the circular shell is formed in a truncated cone 3b reduced in diameter toward the front end side. A slit 3c is provided on the circular shell so as to reduce the diameter of the circular shell. A projecting portion 4 is projected from the drum portion 2 inside the circular shell 3, and the front end surface of the projecting portion is formed to be flush with the front end surface of the circular shell or in such a manner as to project front ward from the front end surface of the circular shell. In a position free from the shearing surfaces P, Q, a recess groove 2c is bored in the direction opposite to the circumferential direction of the drum portion 2, and a rotation preventing means for a connecting pin 1 is provided for keeping the boring direction of the recess groove in such a manner as to intersect perpendicularly to the longitudinal directions of link plates 6, 7, 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin chain connecting pin and a synthetic resin chain connected by using the connecting pin.

[0002]

2. Description of the Related Art Conventionally, in a metal chain such as a steel chain or a casting chain, one end of a pin is a flange type as a measure for preventing a connecting pin from connecting to a link plate.
A split pin or J pin was inserted into the other end, or the other end was crimped. However, in recent years, plastic chains have come to be widely used in sewers and the like, and it is no longer possible to apply the pull-out prevention measures used for conventional metal chains to the plastic chains. As a solution to this problem, Japanese Utility Model Publication No. 61-2440 discloses a chain connecting pin suitable for a plastic chain. The outline is as follows.

A front side cavity is formed at the front end of the connecting pin, and a front side cavity is connected to form a rear side cavity having a smaller diameter.
The annular shell formed outside the anterior cavity is slit to provide a flexible tongue. When this connecting pin is inserted into the hole of the link plate, the annular shell elastically deforms to reduce its diameter, and when the annular shell penetrates the hole of the link plate, the reduced diameter of the annular shell expands elastically to form the link plate. As a result, interference can be prevented and it becomes possible to prevent disconnection.

[0004]

However, the above-mentioned conventional connecting pin has the following problems. That is, since a thin annular shell is formed at the front end of the connecting pin,
This is not a problem when inserting the pin, but when pulling out the connecting pin, it is not possible to hit with a hammer etc.,
Therefore, there is a problem that a special tool is required for extraction. Further, there is a problem that the rear side cavity is provided in the axial direction of the connecting pin, which reduces the shearing strength of the connecting pin and the strength against bending moment. SUMMARY OF THE INVENTION It is an object of the present invention to provide a chain connecting pin and a chain having a high strength by improving the above-mentioned problems and easily removing the pin.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, that is, a plurality of link plates are formed by penetrating a body portion into a hole formed in the link plate and formed in the link plate. In a chain connecting pin for flexibly connecting each other, an annular shell is provided so as to project from the front end side of the body portion toward the front end side, and a shoulder portion having a larger diameter than the rear end portion of the annular shell is formed into the annular shell. Is formed on the outer surface of the intermediate portion of the annular shell, and the outer surface of the front end portion of the annular shell is formed into a truncated cone shape that reduces its diameter toward the front end side, and the annular shell is provided with one or more slits in the radial direction so that the annular shell can be reduced in diameter. Formed, the protruding portion is provided to project from the body portion inside the annular shell, and the front end surface of the protruding portion is flush with the front end surface of the annular shell, or on the front end side of the front end surface of the annular shell. It is characterized in that it is formed to project, and the shearing surface of the connecting pin is In the evading position, one or a plurality of pairs of recessed grooves are bored from a direction opposite to the circumferential direction of the body portion by 180 degrees, and the bored direction of the recessed grooves is maintained in a direction orthogonal to the longitudinal direction of the link plate. A connecting pin for a chain, characterized in that a rotation preventing means for the connecting pin is provided, a plurality of link plates made of synthetic resin, and a body formed in a hole formed in the link plate. In a chain having a connecting pin that pierces the
An annular shell is provided so as to project from the front end side of the body portion of the connecting pin toward the front end side, and a shoulder portion having a diameter larger than that of the rear end portion of the annular shell is formed on the outer surface of the intermediate portion of the annular shell. The outer surface of the front end portion of which is formed into a truncated cone shape having a diameter reduced toward the front end side, and the annular shell is provided with one or a plurality of slits in the radial direction so as to be capable of reducing the diameter of the annular shell. A projecting portion is provided so as to project from the body portion, and a front end surface of the projecting portion is formed so as to be flush with the front end surface of the annular shell, or to project toward the front end side from the front end surface of the annular shell. In a position to avoid the above, one or a plurality of pairs of recessed grooves are bored from a direction opposite to the circumferential direction of the body portion by 180 degrees, and a flange is provided on the rear end side of the body portion of the connecting pin, and an outer peripheral surface of the flange is provided. At least a part of the groove is formed in a plane shape, and the direction of drilling of the groove is perpendicular to the longitudinal direction of the link plate. Is a chain, characterized in that the formation of the boss said flange mating to the outer surface of the insertion direction rear end of the link plate of the connection pin so as to keep the direction.

[0006]

The present invention will be described with reference to the drawings. 1 to 4
Shows an embodiment of the present invention. The body portion 2 of the connecting pin 1 is formed such that the front side (right side in the drawing) 2a has a small diameter and the rear side (left side) 2b has a large diameter, and the front end of the small diameter body portion 2a. On the side (right end side), an annular shell 3 is provided so as to project toward the front end side. The rear end portion (left end portion) of the annular shell 3 is formed to have the same diameter as the small-diameter body portion 2a, and a shoulder portion 3a having a larger diameter than the rear end portion is formed on the outer surface of the intermediate portion of the annular shell 3. The outer surface of the front end portion of the annular shell 3 is formed as a truncated conical taper surface 3b having a diameter reduced toward the front end side. The annular shell 3 is provided with six slits 3c extending in the radial direction at equal angular intervals in the circumferential direction, whereby the annular shell 3 is formed so that its diameter can be reduced. Inside the annular shell 3, a projecting portion 4 is concentric with the annular shell 3 and has a small-diameter body portion 2.
The front end surface (right end surface) of the projecting portion 4 projects further toward the front end side than the front end surface of the annular shell 3.

The body portion 2 of the connecting pin 1 is provided with four pairs of concave grooves 2c in a direction opposite to each other by 180 degrees in the circumferential direction. However, as shown in FIGS. 5 and 6, the connecting pin 1 is fitted into the holes 6a, 7a, 8a of the inlet-side outer link plate 6, the inner-link plate 7, and the outlet-side outer link plate 8,
A tensile force acts on each of the link plates 6, 7, and 8, and thus a shearing force and a bending moment act on the connecting pin 1, but a groove is formed at a position that avoids the shearing planes P and Q on which the shearing force acts. 2c is perforated. Further, a flange 5 having a diameter larger than that of the large-diameter body portion 2b is formed on the rear end side (the left end side in the drawing) of the large-diameter body portion 2b, and the flange 5 has a notched circular shape obtained by cutting the circular shape with parallel lines. Has been formed.

On the other hand, the holes 6 formed in each link plate
a, 7a, 8a are formed so as to fit the diameter of the body portion 2 of the connecting pin, that is, as shown in FIG. 6, the hole 8a of the outlet side outer link plate has a small diameter so as to fit the small diameter body portion 2a. Further, the holes 6a, 7a of the outer link plate on the inlet side and the inner link plate are formed to have a large diameter so as to fit the large diameter body portion 2b. Further, on the outer surface of the inlet-side outer link plate 6, the central portion of the truncated cone is horizontal so that the direction in which the concave groove 2c of the connecting pin is formed is orthogonal to the longitudinal direction of each link plate 6, 7, 8. Two bosses 6b, 6b obtained by cutting in the direction are formed.

This embodiment is constructed as described above,
When the connecting pin 1 is press-fitted from the inlet side outer link plate 6, the insertion of each link plate into the holes 6a, 7a, 8a is guided by the tapered surface 3b, and the annular shell 3 is bent by the presence of the slit 3c. Enters the hole of each link plate, and when the shoulder portion 3a projects outward from the outer link plate 8 on the outlet side, the annular shell 3 is released by being pressed by the hole of the link plate and returns to its original shape.
The shoulder portion 4 is locked to the outer surface of the outlet side outer link plate 8, and thus the link plates 6, 7, 8 are flexibly connected to each other by the connecting pin 1. The body 2 of the connecting pin
Can be formed to have the same diameter, but at that time, the holes 6a, 7a, 8a of the respective link plates are also formed to have the same diameter, and the connecting pin 1 is inserted through the hole 6a of the inlet-side outer link plate. Will have to. Therefore, in this embodiment, only the hole 8a of the outlet-side outer link plate is formed to have a small diameter, and only the front end portion of the body portion 2 is formed to have a small diameter so as to conform to this, so that the inlet-side outer link plate and the inner link plate are formed. The work of press-fitting the connecting pin 1 into the holes 6a and 7a is reduced or eliminated.

Next, this connecting pin 1 is connected to the link plate 6,
When removing from 7, 8 if the head of the protruding portion 4 is lightly hit with a wood hammer or the like, the shoulder portion 3a of the annular shell is forcibly reduced in diameter by the outlet side outer link plate 8 and easily removed. it can. When hitting with a wood hammer,
Due to the presence of the protruding portion 4, this portion receives a striking force, and the thin annular shell around it is less likely to be damaged.
Further, if the projecting portion 4 is projected from the annular shell, the annular shell will not be damaged. Further, it is not necessary to use a tool as disclosed in Japanese Utility Model Publication No. 61-12440, and in the work of extracting the pin at the site where the chain is stretched,
Especially, the workability becomes excellent.

Although the connecting pin 1 and the link plates 6, 7, 8 of this embodiment are formed by injection molding of glass fiber reinforced polyacetal, glass fiber-containing polyacetal, polyester or the like may be used. it can. If the thickness of the product to be injection-molded is large at the time of injection-molding the connecting pin, there is a possibility that a shrinkage cavity may occur in that part or a large dimensional change may occur. Therefore, in this embodiment, the groove 2c is provided to limit the wall thickness to about 5 to 6 mm to prevent the occurrence of sink marks. However, the groove 2c has a shear plane P,
Since it is formed only at the position where Q is avoided, it is possible to sufficiently oppose the shearing force acting on the connecting pin 1. Further, since the groove 2c is formed so as to maintain the direction orthogonal to the longitudinal direction of the link plates 6, 7, and 8, it is possible to sufficiently resist the bending moment acting on the connecting pin 1. .. Therefore, the strength of the connecting pin 1 is not impaired by the existence of the concave groove 2c, and thus the diameter of the connecting pin 1 can be reduced.

In the above embodiment, the number of slits 3c formed in the annular shell was six, but the number of slits 3c can be one or more. For example, four or eight slits can be implemented. it can. Further, in the above-described embodiment, the protruding portion 4 is formed in a columnar shape, but in order to reduce the thickness of the protruding portion 4 and suppress the occurrence of sink marks and the like, as shown in FIG.
A hole 4a is formed at the center of the groove, or one or a plurality of slits 4b is provided in the protrusion 4 as shown in FIG. 8, or the protrusion 4 is formed in a triangular shape with each side recessed as shown in FIG. It can also be formed.

[0013]

As described above, the present invention is a chain connecting pin and chain for which the connecting pin can be easily removed and which has a large strength against shearing strength and bending moment.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a connecting pin according to the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a left side view of the same.

FIG. 4 is a right side view of the same.

FIG. 5 is a perspective view showing a state in which the connecting pin and the link plate of the present invention are assembled.

FIG. 6 is a plan sectional view of a chain according to the present invention.

FIG. 7 is a right side view of another embodiment of the connecting pin.

FIG. 8 is a right side view of still another embodiment of the connecting pin.

FIG. 9 is a right side view of still another embodiment of the connecting pin.

[Explanation of symbols]

1 ... Connection pin 2 ... Body 2
a ... small-diameter body 2b ... large-diameter body 2c ... concave groove 3
... annular shell 3a ... shoulder 3b ... taper surface 3
c ... slit 4 ... protrusion 4a ... hole 4
b ... slit 5 ... flange 6 ... inlet side outer link plate 7 ... inner link plate 8 ... outlet side outer link plate 6a, 7a, 8a ... hole 6b ... boss
P, Q ... Shear surface

Claims (4)

[Claims] 1. A chain connecting pin for connecting a plurality of link plates flexibly to each other by penetrating a body portion into a hole formed in a link plate by a synthetic resin, the chain connecting pin being formed from a front end side of the body portion. An annular shell is provided so as to project toward the front end side, a shoulder portion having a diameter larger than that of the rear end portion of the annular shell is formed on the outer surface of the middle portion of the annular shell, and the outer surface of the front end portion of the annular shell is contracted toward the front end side. It is formed in a circular truncated cone shape, the annular shell is provided with one or a plurality of slits in the radial direction so that the annular shell can be reduced in diameter, and a protrusion is projected from the body portion inside the annular shell, A connecting pin for a chain, wherein a front end face of the protruding portion is formed so as to be flush with a front end face of the annular shell or to a front end side with respect to the front end face of the annular shell. 2. A chain connecting pin for connecting a plurality of link plates flexibly with each other by penetrating a body portion into a hole formed in the link plate by a synthetic resin and avoiding a shearing surface of the connecting pin. In the position, one or a plurality of pairs of recessed grooves are bored from a direction opposite to the circumferential direction of the body portion at 180 degrees, and the connecting pin is maintained so that the bored direction of the recessed grooves is maintained in the direction orthogonal to the longitudinal direction of the link plate. A connecting pin for a chain, characterized in that it is provided with a rotation preventing means. 3. A plurality of link plates made of synthetic resin, and a connecting pin made of synthetic resin and having a body portion penetrating through a hole formed in the link plate to connect the link plates flexibly. In the chain, an annular shell is provided so as to project from the front end side of the body portion of the connecting pin toward the front end side, and a shoulder portion having a diameter larger than that of the rear end portion of the annular shell is formed on the outer surface of the intermediate portion of the annular shell. The outer surface of the front end portion of the annular shell is formed into a truncated cone shape that reduces its diameter toward the front end side, and the annular shell is provided with one or more slits in the radial direction so that the annular shell can be reduced in diameter. A protrusion is provided inside the body, and a front end face of the protrusion is formed so as to be flush with the front end face of the annular shell or protruded toward the front end side from the front end face of the annular shell. Around the body at a position that avoids shear planes One or a plurality of pairs of recessed grooves are bored from the direction opposite to each other by 180 degrees, a flange is provided on the rear end side of the body portion of the connecting pin, and at least a part of the outer peripheral surface of the flange is formed into a flat shape, A boss that fits with the flange is formed on the outer surface of the link plate on the rear end side in the insertion direction of the connecting pin so that the direction in which the groove is formed is maintained in the direction orthogonal to the longitudinal direction of the link plate. Chen. 4. The link pin according to claim 3, wherein the front portion of the body portion of the connecting pin is formed to have a smaller diameter than the rear portion, and the diameter of the hole of the link plate is formed so as to match the diameter of the body portion. Chen.