JPH0994617A - Production of sprocket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sprocket production method by which the production cost is reduced and a sprocket capable of enduring transmission of a high load force is produced. SOLUTION: A sprocket 10 is produced from a metal plate 20 (steel plate) provided for a stock. The method consists of a punching process P1 to punch the part corresponding to a tooth groove 12 between each tooth of the sprocket 10 in the metal plate 20 in a hole shape, a coining process P2 to coin the part corresponding to each tooth to form a prescribed tooth width T after the punching process P1, a shaving process P3 to shave the periphery of each tooth 11 after the coining process P2 and a process P4 to cut off a tooth tip 11b of each tooth 11 from the metal plate 20 after the shaving process P3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprocket manufacturing method for manufacturing a sprocket from a metal plate.

[0002]

2. Description of the Related Art Conventionally, for example, in order to manufacture a sprocket 10 for a chain as shown in FIGS. 11, a method of forming each tooth 11 by punching from a metal plate with a press, and then forming to a predetermined tooth width T by turning, (4) a method of forming by injection molding using a resin and so on.

[0003]

However, the above (1)
The sinter molding method has a problem of high cost. (2) In the method of shaping each tooth 11 by gear cutting after shaping the outer appearance by turning, there is a problem in that manufacturing takes time and costs increase. (3) In the method of forming each tooth 11 by punching from a metal plate with a press and then forming to a predetermined tooth width T by turning, since it has turning, it takes time to manufacture and the cost is high. There is a problem of becoming. (4) In the method of molding by injection molding using a resin, a large amount can be molded in a short time and cost can be reduced.
The sprocket molded by this method has a problem that it can be used only for transmission of a low load force.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to manufacture a sprocket which can reduce the manufacturing cost and can withstand the transmission of a high load force. It is to provide a sprocket manufacturing method capable of performing the above.

[0005]

In order to achieve the above object, the present invention is a sprocket manufacturing method for manufacturing a sprocket from a metal plate provided as a material, wherein the teeth between the teeth of the sprocket in the metal plate are A punching step of punching a portion corresponding to the groove into a hole shape, a coining step of coining the portion corresponding to each tooth after the punching step to form a predetermined tooth width, and each of the above-mentioned after the coining step The method is characterized by including a shaving step of shaving the periphery of the tooth and a cutting step of cutting the tip of each tooth from the metal plate after the shaving step.

It is preferable that the metal plate is formed in a strip shape continuous from the punching process to the cutting process.

According to the present invention, in the punching step, the portion corresponding to the tooth space is punched into a hole shape by a press. Then, in the coining step, a portion corresponding to each tooth is pressed to form a predetermined tooth width. At this time, since the tooth space has already been formed, the excess metal due to coining easily protrudes toward the tooth space. That is, coining can be performed with a small force. Moreover, the work is hardened by coining, and the strength of each tooth is improved. Next, in the shaving step, the portion protruding to the tooth groove side is removed by, for example, finish punching. As a result, the protruding portion on the tooth groove side is deleted, and the periphery of each tooth is finished. Then, in the cutting step, the tip of each tooth is cut from the metal plate. As a result, a single sprocket separated from the metal plate is completed.

Therefore, since there is no need for turning,
The sprocket can be manufactured in a short time, and the manufacturing cost of the sprocket can be reduced. Moreover,
Since a series of work from the punching process to the cutting process can be performed by press working, these works can be automated, and this automation can further reduce the cost. Further, the work hardening by coining improves the strength of each tooth, so that it is possible to manufacture a sprocket that can withstand the transmission of a high-load force.

Further, if the metal plate is formed in a band shape and the metal plate is continuously supplied from the punching process to the cutting process, the position of the metal plate in each process is uniquely determined. Therefore, the manufacturing efficiency can be improved and the manufacturing time can be further shortened.

[0010]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, 20 is a strip-shaped steel plate (metal plate) from which the chain sprocket 10 shown in FIGS. 3 to 4 is manufactured. The sprocket 10 has a plurality of teeth 11 around it, and each tooth 1
A roller (not shown) of the chain is fitted in the tooth space 12 between the rollers 1. The tooth width T of each tooth 11 is formed to be a curved surface R toward the tip. Further, a spline hole 13 is formed at the center, and the screw holes 14 and 1 are formed at point symmetrical positions with respect to the spline hole 13.
4 are provided. As shown in FIG. 1, the sprocket 10 includes a punching process P1, a coining process P2,
It is manufactured by a manufacturing apparatus including a shaving process P3 and a cutting process P4. However, the punching process P1 is divided into a first process P1a and a second process P1b. And each process P1a, P1b, P2, P
The positions of 3 and P4 are arranged on a straight line.

Next, a method of manufacturing the sprocket 10 with the above manufacturing apparatus will be described.

First, the strip-shaped steel plate 20 moves to the first step P1a of the punching step P1. In this first step P1a, as shown in FIG. 1, every other tooth groove hole 22 corresponding to each tooth groove 12 of the sprocket 10 is punched by a press. At the same time, the spline pilot hole 23 and the positioning hole 25
Punch out. A sectional view of the steel plate 20 is as shown in FIG.

In this way, when the work of the first step P1a is completed, the entire steel plate 20 moves, and the part punched out of the tooth space hole 22 moves to the second step P1b. In the second step P1b, as shown in FIG. 1, the tooth slot 22 which is not punched in the first step P1a is punched. This allows
All the tooth spaces 22 corresponding to the tooth spaces 12 of the sprocket 10 are punched out, and the teeth 11 are formed between the tooth spaces 22. FIG. 2B is a sectional view of the steel plate 20.
become that way.

Here, in the punching process P1, the portion 26 between the sprocket 10 in the first process P1a and the sprocket 10 in the second process is punched. This smoothes the movement of the extra thickness 11a in the coining process P2.

In this way, when the work of the second step P1b is completed, the entire steel plate 20 moves, and the portion punched out of the tooth space hole 22 moves to the coining step P2. In this coining step P2, the teeth 11 are coined as shown in FIG. Then, as shown in FIG. 2C, as the tooth width T of the tooth 11 approaches the tip, the curved surface R
It is thinly formed. As a result, the tooth width T portion of the sprocket 10 is completed. However, as shown in FIG. 1, the metal left over by coining is in a state of protruding to the side of the tooth space 22 as the extra thickness 11a. The screw holes 14 and 14 are also formed at the same time during coining.

When the work in the coining step P2 is completed in this way, the entire steel plate 20 moves, and the portion punched out of the tooth space hole 22 moves to the shaving step P3. In the shaving process P3, as shown in FIG. 1, the surplus thickness 1 protruding to the side of each tooth space 22 by finish punching.
Delete 1a. As a result, the tooth groove 12 portion of the sprocket 10 is completed. At the same time, spline pilot hole 2
Finishing punching is performed on the portion 3 to form the spline hole 13. FIG. 2 is a sectional view of the steel plate 20.
It becomes like (d).

When the work in the shaving process P3 is completed in this way, the entire steel plate 20 moves, and the shaving processed part moves to the cutting process P4. In the separating step P4, as shown in FIG. 1, the tip 11b of each tooth 11 is separated from the steel plate 20. As a result, FIG.
As shown in (e), the sprocket 10 having the teeth 11 on the outer peripheral portion is completed.

Therefore, according to the method of manufacturing the sprocket 10 configured as described above, since the turning process is not required, the sprocket 10 can be manufactured in a short time, and the manufacturing cost of the sprocket 10 can be reduced. Can be planned. Moreover, since a series of operations from the punching process P1 to the cutting process P4 can be performed by the press,
These manufacturing steps can be automated, and the automation can further reduce the cost. Moreover, since the strength of each tooth 11 can be improved by work hardening by coining, the sprocket 10 that can withstand the transmission of a high-load force can be manufactured. Moreover, since coining is performed after the tooth space 22 is formed, excess meat can be easily protruded toward the tooth space 22 by coining. Therefore, coining can be performed with a small force.

Further, the steel plate 20 is composed of a strip,
By moving the steel plate 20 from the punching process to the cutting process, the position of the steel plate 20 in each process is uniquely determined. Therefore, it is possible to save the labor of providing the steel plate 20 in each process, and thus it is possible to improve the manufacturing efficiency, shorten the manufacturing time, and reduce the manufacturing cost.

In the above embodiment, the strip-shaped steel plate 20 is used, but it goes without saying that the strip-shaped steel plate 20 need not be used. That is, a steel plate having a square shape, a circular shape, or any other shape may be used as long as the sprocket 10 can be molded. Further, it goes without saying that the plate is not limited to the steel plate 20 as long as it can be processed by pressing, and a plate made of another metal may be used.

Further, the screw hole 14 is formed in the coining step P2.
However, the screw hole 14 may be formed in a process completely different from the processes P1, P2, P3 and P4.

[0023]

As described above, according to the present invention, since it is not necessary to perform the turning process, the sprocket manufacturing time can be shortened and the manufacturing cost can be reduced. Moreover, since a series of work from the punching process to the cutting process can be performed by press working, these works can be automated, and the cost can be further reduced by this automation. Moreover, since the strength of each tooth can be improved by work hardening by coining, it is possible to manufacture a sprocket that can withstand the transmission of a high-load force. Moreover, since excess meat can be easily protruded toward the tooth space by coining, coining can be performed with a small force.

Further, if the metal plate is formed in a strip shape and the metal plate is continuously supplied from the punching process to the cutting process, the position of the metal plate in each process is unique. Since it is determined, the manufacturing efficiency can be improved, and further the manufacturing time and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing each step in a sprocket manufacturing method shown as an embodiment of the present invention.

FIG. 2 is a view showing a cross section of the steel plate after finishing each step of the sprocket manufacturing method.

FIG. 3 is a front view of a sprocket manufactured by the same sprocket manufacturing method.

4 is a sectional view of a sprocket manufactured by the same sprocket manufacturing method, which is a sectional view taken along line IV-IV of FIG.

[Explanation of symbols]

 10 Sprocket 11 Tooth 11b Tooth Tip 12 Tooth Groove 20 Metal Plate (Steel Plate) P1 Punching Process P2 Coining Process P3 Shaving Process P4 Cutting Process

Claims (2)

[Claims] 1. A sprocket manufacturing method for manufacturing a sprocket from a metal plate provided as a material, comprising a punching step of punching a portion of the metal plate corresponding to a tooth groove between teeth of a sprocket into a hole shape, A coining step of coining a portion corresponding to each tooth after this punching step to form a predetermined tooth width, a shaving step of shaving the periphery of each tooth after this coining step, and a shaving step after this shaving step A sprocket manufacturing method comprising: a cutting step of cutting the tip of each tooth from a metal plate. 2. The sprocket manufacturing method according to claim 1, wherein the metal plate is formed of a belt-shaped member which is continuous from the punching process to the cutting process.