JPH0673522U - Toothed belt pulley - Google Patents

Abstract

(57) [Abstract] [Purpose] Toothed belt pulleys that can be manufactured inexpensively and in large quantities by resin molding without using conventional machining,
Make the resin molding die as simple as possible. A toothed belt pulley comprising flanges 4 and 9 on both sides of a toothed portion 3 for meshing the toothed belt to prevent the toothed belt from coming off and to guide the toothed belt. 3 and one of the flange portions 4 and the pulley body 1 which is resin-molded so as to integrally provide the engaging hole 5, and the other of the flange portion 9 and the engaging hole 5 are engaged with each other to maintain the engaged state. And the flange body 2 which is resin-molded so as to integrally provide the engaging body 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a toothed belt pulley, which is used, for example, in a state in which the toothed belt is stretched in order to reliably transmit a predetermined rotational driving force without slipping.

[0002]

[Prior art]

 Conventionally, various toothed belts such as timing belts and micro pitch belts have been provided in an endless state in which a desired number of teeth are integrally provided. Further, as the toothed belt pulley that meshes with this toothed belt, various pulleys having a desired number of teeth are also used according to the purpose.

Among the pulleys for toothed belts used in this way, those for micro-pitch belts are very difficult to store as a standard inventory because there are many variations in the number of teeth Z and others. However, pulleys are often handled as so-called ordered products, and are generally manufactured after receiving an order. Further, the material of the pulley is often made of aluminum (A5052, etc.), and a belt guide flange provided on both sides of the tooth is often used.

As described above, the manufacturing process of the conventional pulley for the micro pitch belt will be briefly described with reference to the external perspective view of the blank of FIG. 5 and the pulley manufacturing process of FIG. When the desired number of teeth Z of the pulley is 15, prepare a blank 30 (for example, a total length of 30 cm), and cut the teeth for this number of teeth on the outer peripheral surface in advance by using a hob cutter device or the like. I'll do it. After that, the blank 30 is centered on the lathe and chucked, and then the blank 31 is cut into a desired outer shape using a drill 31, a cutting tool 32, etc., and the teeth are removed from the blank 30 as shown in FIG. A shape having only the portion 40 left is prepared. Further, the outer shape portion 39 that matches the caulking hole portion 35 of the flange body 34 prepared in advance is processed on both sides, and the boss portion 36 is processed with the screw hole 38 for fixing.

After the above-mentioned preparation, two pieces of the flange body 34 are inserted (press-fitted) into each outer shape portion 39, and then the flange body 34 is caulked by using a caulking tool to form one pulley. It is completed.

[0006]

[Problems to be solved by the device]

 As described above, since the conventional pulley is manufactured through a great number of processes, there are various problems such as being expensive and requiring a long delivery time. Therefore, the toothed belt pulley of the present invention has been made in view of the above-mentioned problems, and its purpose is for toothed belts that can be manufactured inexpensively and in large quantities by resin molding without using conventional machining. To provide a pulley.

Another object is to make the resin molding die as simple as possible.

[0008]

[Means for Solving the Problems] and

[Action]

 In order to solve the above problems and achieve the object, a pulley for a toothed belt of the present invention has the following configuration. That is, in order to prevent the toothed belt from falling off and to guide the toothed belt in a predetermined manner, a toothed belt pulley is provided with flange portions on both sides of the toothed portion that meshes with the toothed belt. A pulley main body that is resin-molded so that one side and an engagement hole are integrally provided, and an engagement body that is engaged with the other side of the flange portion with respect to the engagement hole and maintains an engaged state are integrally provided. And a flange body formed by resin molding. After the resin molding, the flange body is engaged with the engagement hole of the pulley main body and the engaged state of the engagement body is maintained to complete the toothed belt pulley.

[0009] Preferably, a plurality of engaging holes are provided at one side surface portion of the flange portion, and a plurality of engaging bodies are substantially vertically provided from the other side surface portion of the flange portion. A pulley for a toothed belt is completed by having a locking claw that locks a part of the dowel hole and holding the locking by the elastic force of the resin.

[0010] Preferably, in order to injection-mold the pulley body and the flange body, the main molding surfaces of the pulley body and the flange body are arranged on one side so that there is no under-molding surface in the mold opening direction. The shape of the cavity of the injection mold is made so that the molded product can be taken out after opening the mold.

[0011]

【Example】

 A preferred embodiment of the toothed belt pulley of the present invention will be described in detail below with reference to the drawings. First, FIG. 1 is a three-dimensional exploded view of a pulley for a toothed belt, showing how the pulley used for the above-mentioned micropitch belt is assembled.

In the figure, the pulley body 1 is formed with a predetermined number of tooth portions 3 having a tooth shape with which the micro pitch belt meshes, as shown in the figure, and one side of the tooth portion 3 is detached from the belt. A flange portion 4 for preventing the above and for guiding a predetermined amount is integrally formed, and is formed so as to also serve as a base portion of the pulley main body portion 1. A boss 6 having a center hole 8 of a predetermined inner diameter, which is the center of rotation of the pulley, is hung from the central portion of the flange 4, while the outer periphery of the boss 6 is equally spaced by 120 degrees. Thus, the reinforcing portion 7 is continuously formed so as to be continuous between the inner peripheral surfaces of the tooth portion 3. The outer peripheral surface of the boss portion 6 has a predetermined outer diameter to ensure a predetermined wall thickness around the central hole 8, and when the flange body 2 to be described later is assembled to the pulley body 1, The outer peripheral surface of the boss portion 6 is used for guiding. Further, as shown partially broken in the drawing, the flange portion 4 is provided with rectangular engaging hole portions 5 for assembling integrally with the flange body 2 at equal intervals of 120 degrees.

Next, the flange body 2 is engaged with the engagement hole portion 5 of the pulley main body portion 1 to form a flange portion on one side of the tooth portion 3. For this reason, the flange body 2 has the flange portion 9 having substantially the same outer diameter as that of the above-mentioned flange portion 4 as a base portion, and the engaging bodies 10 are provided at equal intervals of 120 degrees, and are formed in a part of the engaging hole portion 5 at the tip portion. An engagement body 10 having a locking claw portion 11 for locking is provided.

That is, as shown in the sectional view taken along the engagement hole 5 after assembly in FIG. 2, the engagement body 10 is made of resin when the engagement body 10 is locked to the engagement hole 5. Since the outwardly-held state is held by the elastic force, the state in which the locking claw portion 11 is locked to the edge of the engagement hole portion 5 with the protrusion from the engagement hole portion 5 to the outside. It can be held. Further, in FIG. 2, a screw hole 20 for fixing the pulley may be post-processed in the thick portion of the boss portion 6.

On the other hand, referring to FIG. 1 again, a guide hole 15 is provided at the center position of the flange body 2, and the guide hole 15 is formed in the arrow A direction with respect to the boss portion 6 of the pulley body 1. The engaging body 10 is automatically guided (arrow A1) to the position of the engaging hole portion 5 by inserting the engaging body 10 into the engaging hole portion 5, so that the assembling work can be simplified. As described above, the toothed belt pulley in which the engaged state of the engaging body 10 is maintained is completed.

Since the pulley thus completed is injection-molded from a predetermined resin material, one consideration is that the pulley body 1 and the flange portion 4 of the flange body 2 and the tooth portion 3 are provided. The thickness of the boss 6 and other parts does not change suddenly, but in addition to this, the pulley body 1 and the flange body 2 are simultaneously resin-molded via a gate provided from a common runner. I am trying.

FIG. 3 is an external perspective view showing a state where a pulley body and a flange body are injection-molded through a gate that branches from a common runner, and an external perspective view showing a state of a die cavity for obtaining this molded product. Is. In this figure, the pulley body 1 and the flange body 2 are provided so that the gate portion 17 communicating with the respective flange portions 4 and 9 is branched from the common runner 19, while the mold opening direction (arrow B1, B2 direction) The main molding surfaces of the pulley body and the flange body are arranged on one side so that there is no under molding surface. For this purpose, for example, an escape hole portion 12 continuous from the side surface portion 10f of the engaging body 10 is formed in the flange portion 9 of the flange body 2, and a rod hanging from the cavity C1 to the escape hole portion 12 is provided. By infiltrating the member C5, the engaging bottom surface portion of the engaging claw portion 11 can be formed so that the under molding surface can be eliminated.

In other words, when the pulley body 1 and the flange body 2 are not arranged in this way and the pulley body 1 and the flange body 2 are already integrally resin-molded at the molding stage, the under molding surface Since the number of molds increases, the mold becomes very complicated, and as a result, the original purpose of cost reduction cannot be achieved.

FIG. 4 is a three-dimensional exploded view of the pulley obtained as described above applied to a photographic paper cutting device for a photographic developing machine, when it is used in an environment where it is constantly exposed to a developing solution and a cleaning solution. Is. In this figure, as shown in the drawing, the pulley 21 is meshed with the belt 23 in a stretched state, and by transmitting the driving force of the output shaft 25 of the motor 26 to each pulley 21, the desired conveyance is achieved. It is configured to drive the rotation of the rollers.

Since the pulley used as described above is formed by using the resin material having the corrosion resistance against the developing solution and the cleaning solution, there is no problem such as erosion and it can be made extremely lightweight. Power transmission response is good.

The embodiment described above is not limited to the case where three engaging bodies are provided at equal intervals, and four or more engaging bodies are provided as necessary, or the positions where the engaging bodies are arranged are appropriately shifted. But needless to say. Needless to say, when it is not necessary to provide flanges on both sides, only the pulley body 1 may be used. Further, the present invention is not limited to the micro pitch pulley, but can be similarly applied to a normal inch type type timing belt pulley.

The fixing to the rotary shaft is not limited to the screw fixing as described above. For example, when the fixing is performed by D cut, the inner surface of the center hole 8 may be D cut shape. There is no need for post-processing.

[0023]

[Effect of device]

 As described above, according to the toothed belt pulley of the present invention, it is possible to provide a toothed belt pulley that can be manufactured inexpensively and in large quantities by resin molding without machining. Further, the resin molding die can be constructed as easily as possible.

[Brief description of drawings]

FIG. 1 is a three-dimensional exploded view of a pulley for toothed belt according to an embodiment.

FIG. 2 is a fragmentary cutaway view of the toothed belt pulley after assembly.

FIG. 3 is an appearance of a toothed belt pulley after injection molding,
It is an appearance perspective view of a metallic mold.

FIG. 4 is a three-dimensional exploded view of a usage example of a pulley.

FIG. 5 is an external perspective view of a conventional blank.

FIG. 6 is a conventional pulley manufacturing process drawing.

[Explanation of sign]

 DESCRIPTION OF SYMBOLS 1 pulley main body part, 2 flange body, 3 tooth part, 4 flange part, 5 engaging hole part, 6 boss part, 7 reinforcing part, 8 center hole, 9 flange part, 10 engaging body, 11 engaging claw part, 12 There are escape holes, 15 guide holes, 17 gate parts, and 19 runners.

Claims (3)

[Scope of utility model registration request] 1. A pulley for a toothed belt, comprising flange portions provided on both sides of a tooth portion that meshes with the toothed belt in order to prevent the toothed belt from falling off and to guide the toothed belt in a predetermined manner. And one of the flange portions and a pulley main body that is resin-molded so as to integrally provide an engagement hole, and an engagement body that is engaged with the other of the flange portions and the engagement hole to maintain an engaged state. And a flange body which is molded by resin so as to be integrally provided with a pulley for a toothed belt. 2. A plurality of the engaging holes are provided at one side surface portion of the flange portion, and a plurality of the engaging bodies are substantially vertically provided from the other side surface portion of the flange portion, The pulley for toothed belt according to claim 1, further comprising a locking claw that locks a part of the engagement hole, and holds the locking by an elastic force of the resin. 3. When the pulley body and the flange body are injection-molded, the main molding surfaces of the pulley body and the flange body are arranged on one side so that there is no under-molding surface in the mold opening direction. A pulley for a toothed belt characterized by.