JP2002168302A - Toothed belt, tooth cloth shaping method and toothed belt manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothed belt having effectively less root cracking trouble peculiar to the toothed belt, a tooth cloth shaping method and a toothed belt manufacturing method. SOLUTION: The toothed belt 1 comprises a tooth cloth 2 located at a tooth bottom portion P of the toothed belt 1, having a yarn density (represented by the density of a warp 2b) finer than the yarn density thereof located at a tooth top portion Q. The manufacturing method comprises the tooth cloth 2 by preliminarily shaping using a press forming die with first and second male molds operated in two-stage linkage and manufacturing the tooth belt 1 using the shaped tooth cloth 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt, a method for forming a toothed belt, and a method for manufacturing a toothed belt. More specifically, the present invention relates to a toothed belt in which a plurality of teeth are covered with a toothed cloth, and a tooth used therefor. The present invention relates to a method of forming a cloth and a method of manufacturing a toothed belt.

[0002]

2. Description of the Related Art Toothed belts used for power transmission belts of automobile engines and the like are constantly required to have improved durability due to their severe operating conditions, and materials and other improvements are made on a daily basis. I have. For example, a toothed belt having a plurality of teeth on one side in the longitudinal direction, a back on the other side, and a core wire arranged between the teeth and the back, for reinforcing the plurality of teeth. 1 is a toothed belt in which a tooth cloth is covered with a tooth cloth.

[0003] One of the reinforcing effects of the tooth cloth is a reinforcing effect on the wear resistance due to the high wear strength of the material itself against the contact wear with the toothed pulley, and the second is an expandable and contractible effect. This is a reinforcing effect on the bending resistance of the root portion coming from the soft structure caused by folding of the tooth cloth weft (belt longitudinal direction).

[0004] Hereinafter, a method of molding a tooth cloth for a toothed belt and a method of manufacturing the toothed belt according to the prior art will be described in detail.

[0005] First, in a first method, an unvulcanized tooth cloth with rubber having a predetermined width and a predetermined length manufactured through a predetermined canvas processing step is jointed into a cylindrical shape, and this cylindrical tooth cloth is processed. Is inserted into the outer periphery of a grooved mold having a plurality of tooth shapes in the circumferential direction, a core wire is spirally wound thereon, and an unvulcanized rubber sheet is further wound thereon to form a preform.

[0006] The preformed body obtained in this manner is inserted into a vulcanizing can, a predetermined belt sleeve is manufactured by heating and pressing, and the obtained belt sleeve is cut into a predetermined width using a belt width cutting device. This is a method of finishing a toothed belt. In this method, a step of forming a tooth cloth is performed simultaneously with a step of heating and pressing in a vulcanizing can.

A second method is to fit a cylindrical tooth cloth into the grooved mold, form an unvulcanized rubber sheet thereon, form a preform, and further form a release paper around the preform. Inserted, covered with a rubber jacket and inserted into a vulcanizing can, made into a semi-vulcanized state under predetermined heating and pressurizing conditions, molding a tooth cloth in this semi-vulcanized state, and then removing the preformed body. Take it out of the vulcanizing can, attach this preformed body to the molding machine again, and wrap the core wire around its outer periphery spirally under a constant tension,
Further, an unvulcanized rubber sheet is wound thereon to produce a preform.

Although this method complicates the molding process, it has the effect of more accurately creating the tooth shape as the final product.

[0009] A third method is that the method of molding the tooth cloth is as follows.
An unvulcanized tooth cloth with rubber manufactured through a predetermined canvas processing step is laid on a lower mold in which tooth portions and tooth groove portions are alternately engraved in the longitudinal direction, and a predetermined number of protrusions having the same plurality of protrusions from above. The upper mold is lowered, the tooth cloth is pressed, heated and pressurized under predetermined conditions, and the mold is formed into a semi-vulcanized state.

The preliminarily obtained semi-vulcanized tooth cloth is cut into a predetermined width and a predetermined length, processed into a tubular shape by heat fusion or a sewing machine joint, and fitted into a grooved mold. Alternatively, the above-described molded tooth cloth is wound around the outer periphery of the grooved mold in a cylindrical shape, and both ends of the tooth cloth are locked with a rubber tape.

The subsequent steps are the same as in the first method, and a description thereof will be omitted. This third method also complicates the molding process similarly to the second method, but has the effect of accurately creating the tooth shape of the tooth portion as the final product.

[0012]

However, the following problems are observed in the toothed belt manufactured by the conventional method for manufacturing a toothed belt, and the following problems will be described. That is, in the first method, a stretchable tubular tooth cloth is fitted into a grooved mold, a core wire is spirally wound thereon, and an unvulcanized rubber sheet is further wound thereon. In this method, a preformed body is prepared, and then the preformed body is inserted into a vulcanizing can, and a toothed belt is manufactured by heating and pressing.

According to this method, the tooth cloth is pressed and expanded into the tooth groove portion of the front grooved mold by the flow force of the unvulcanized rubber sheet wound behind the tooth cloth, and a predetermined tooth shape is formed. Since the tooth cloth is intended to be shaped into a shape, more tooth cloth is accumulated on the frontmost surface (corresponding to the crest of the tooth part when viewed from a completed toothed belt). .

This state will be described with reference to FIG. In FIG. 6, the tooth cloth 2 is made of a stretchable canvas woven by a weft 2a arranged in the longitudinal direction of the toothed belt and a warp 2b arranged in the width direction of the toothed belt.
Behind it, a core wire 4 is spirally wound. The unvulcanized rubber sheet is fluidized through the heating and pressurizing process, and finally forms the teeth 3 and the back 5.

At this time, the expandable and contractible tooth cloth 2 is accumulated more at the tooth top indicated by the reference symbol Q, and as a result, the tooth cloth 2 is accumulated relatively less at the tooth bottom indicated by the reference sign P. That is, the yarn density (the weft 2a
The yarn density at the bottom of the tooth (the yarn amount of the weft 2a) indicated by the symbol P decreases.

That is, in the toothed belt 1 manufactured by this method, the thread density of the tooth cloth 2 at the tooth bottom is relatively lower than that at the tooth top, so that the tooth belt 1 is less susceptible to tooth root cracks generated at the tooth bottom. Reducing the strength relatively. This aspect has the same result in the second method. The difference is that the generation of the tooth profile is more accurate when the second method is used than in the first method. The distribution state of the yarn density of No. 2 does not change.

A third method is to preliminarily mold only the tooth cloth 2 as shown in FIG. 4. Specifically, the tooth cloth 2 laid on the lower mold 11 is removed. Upper mold 10 from above
Is a method of forming a predetermined tooth shape by lowering, heating and pressurizing, but this method is also similar to the first and second methods, even though the tooth shape itself may be more accurate, The thread density of the tooth cloth 2 cannot be optimally changed.

The present invention is intended to solve such a problem, and focuses on the yarn density of a tooth cloth used for reinforcing a tooth portion, and optimizes this yarn density in accordance with the tooth portion. It is an object of the present invention to provide a toothed belt, a method of forming a tooth cloth, and a method of manufacturing a toothed belt, which are changed to maximize the original reinforcing effect.

[0019]

According to a first aspect of the present invention, in a toothed belt in which a plurality of teeth arranged in a longitudinal direction are covered with a tooth cloth, the belt is woven in a belt width direction of the tooth cloth. The longitudinal density of the warp yarn is a toothed belt in which the density at the tooth bottom is finer than that at the tooth top.

According to a second aspect of the present invention, the ratio of the longitudinal density of the warp at the tooth bottom to the longitudinal density of the warp at the apex is:
2. The toothed belt according to claim 1, wherein the ratio is 1.05: 1 to 1.4: 1.

According to a third aspect of the present invention, there is provided a method of molding a tooth cloth used for a toothed belt in which a plurality of teeth arranged in a longitudinal direction are covered with a tooth cloth, wherein the tooth parts and the tooth groove parts are alternately engraved. A tooth cloth is laid on the lower mold that has been set, the first upper mold is brought into contact with the laid tooth cloth, and the tooth cloth is pressed and fixed between the lower mold and the tooth bottom of the tooth cloth in a non-stretched state. After the second upper mold is moved in cooperation with the first upper mold, the second upper mold is brought into contact with the tooth cloth in a protruding state, and the tooth cloth is pressed and tightened in the tooth groove portion of the lower die. This is a method of molding a tooth cloth in which the top of the tooth cloth is molded in an extended state.

According to a fourth aspect of the present invention, the second projecting upper mold is mounted on the first upper mold, and the first upper mold is used as a guide to move toward and away from the lower mold. A method for forming a tooth cloth according to claim 3.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a toothed belt in which a plurality of teeth arranged in a longitudinal direction are covered with a tooth cloth, wherein the tooth cloth and the tooth groove are alternately engraved on the tooth cloth. After laying in the mold, the tooth cloth is pressed and fixed between the lower mold and the first upper mold, and the bottom of the tooth cloth is molded in a non-stretched state. A second upper mold that moves in a protruding state is brought into contact with the tooth cloth, and the tooth cloth is pressed and tightened in a tooth groove portion of the lower mold to form a tooth top of the tooth cloth in an extended state. The above-prepared tooth cloth was placed on the outer peripheral surface of the grooved mold, a core wire was spirally wound thereon, and an unvulcanized rubber sheet was further wound thereon to form a preform. Thereafter, the belt sleeve is vulcanized to produce a belt sleeve, and the resulting belt sleeve is manufactured into a toothed belt having a predetermined width.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a synchronous belt and a method of manufacturing the same according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the toothed belt according to the present invention, and FIG. 2 is a longitudinal sectional view showing the definition of the yarn density of the tooth cloth according to the present invention. FIG. 3 is a schematic view showing a method for forming a tooth cloth according to the present invention, and FIG. 5 is a schematic view showing a method for manufacturing a toothed belt.

First, the features of the toothed belt 1 according to the present invention will be described in detail with reference to the drawings. That is, in FIG. 1, in the toothed belt 1 of the present invention, the yarn density of the tooth cloth 2 is relatively high at the bottom of the tooth portion 3 indicated by the reference symbol P, and A toothed belt characterized in that the yarn density is relatively small.

Here, a method of measuring the yarn density of the tooth cloth 2 will be described below with reference to FIG. In FIG.
In the toothed belt 1, since the tooth cloth 2 at the bottom of the tooth indicated by the symbol P is accumulated relatively more than the other parts, the yarn density represented by the warp yarn 2b increases.

That is, in FIG. 2, lowercase letters a, b,
The distances between the warps indicated by c, d, and e are capital letters A, B,
It is smaller than the distance between the warps indicated by C, D and E.
Therefore, if this distance is measured and statistically processed, the degree of integration of the cloth 2, that is, the yarn density can be properly evaluated. Specifically, for example, the side surface of the toothed belt 1 can be scanned and imaged with a microscope, and the position of the warp can be read as data by image processing. Calculate the distance,
Statistical processing can be performed.

However, the method for evaluating the yarn density is not limited to the above-mentioned method, but any method can be used as long as the method can evaluate the degree of accumulation of the tooth cloth 2.

The rubber material for the rubber sheet forming the teeth 3 and the back 5 of the toothed belt 1 shown in FIG.
Hydrogenated nitrile rubber (H-NBR), chloroprene rubber (CR), chlorosulfonated polyethylene (CS
M), acrylonitrile butadiene copolymer (NB
R), ethylene propylene diene monomer (EPD
M), ethylene propylene copolymer (EPR), styrene butadiene copolymer (SBR) isoprene rubber (I
R), natural rubber (NR), acrylic rubber (ACM), fluorine rubber (FPM), silicon rubber (Si), urethane rubber (U), and the like.

The tooth cloth 2 is generally made of a woven cloth made of an aliphatic polyamide (nylon) fiber such as nylon 6, nylon 6, 6, or the like, which is bonded. Such a material can be applied to the invention. In order to further improve the wear resistance of the tooth cloth 2, it is preferable to use a woven cloth made of aramid fiber. As the aramid fiber, poly-paraphenylene terephthalamide, poly-metaphenylene isophthalamide, poly-paraphenylene 3,4-diphenylether-terephthalamide, or the like can be used.

The tooth cloth 2 may be made of aliphatic polyamide (nylon) fibers such as nylon 6, nylon 6,6 and the like.
Polyester, aramid fiber or the like may be used alone or in combination.

The structure of the warp 2a (belt width direction) and the weft 2b (belt length direction) of the tooth cloth 2 is also a filament yarn or a spun yarn of the above-mentioned fiber, and the woven structure is any of plain fabric, twill fabric, satin fabric and the like. May be.

The use of a stretchable urethane elastic yarn as the weft and the use of aramid fiber for the weft can reduce the friction coefficient of the tooth cloth and improve the chipping resistance. I can do it.

The core wire 4 wound around the back of the tooth portion 3 is not particularly limited. A glass core wire or an aramid core wire can be used, and polybenzoxazole, polyparaphenylene naphthalate, polyester , Acrylic, car
Twisted cords composed of two or more kinds of compositions such as Bon, Steel and the like can also be used. The composition of the glass core wire may be either E glass or S glass (high-strength glass),
The thickness of the filament and the number of converging filaments are not limited, and can be selected according to the use of the toothed belt 1.

In addition, adhesives for glass or steel-contaminated cords, sizing agents for protecting glass filaments when bent, RFL (resorcin-formalin-latex), overcoat agents, etc. Not restricted. Further, the aramid core wire is not limited by the difference in the molecular structure of the material, the core wire configuration, the size of the filament, or the adhesive treatment agent. Similarly, there is no particular limitation on the twisted cord of a core wire having another composition.

Next, a method of forming a tooth cloth used for the toothed belt 1 according to the present invention will be described in detail below. That is,
In FIG. 3, a mold for molding the tooth cloth 2 which is a feature of the present invention includes a lower mold 11, a first upper mold 20a, and a base 21.
And a second upper die 20b fixed to the press die, and shows that the die forming process proceeds in the order of FIGS. 3 (a), 3 (b) and 3 (c). .

The tooth cloth 2 is laid first on the lower mold 11, and thereafter, the first cloth is moved by the actuator (not shown).
The upper mold 20a is lowered from above, and the tooth cloth 2 is moved from FIG.
The tooth cloth 2 located at the bottom of the tooth including the K portion shown in (b) is firmly fixed. Thereafter, the second upper mold 20b operating in cooperation with the first upper mold 20a is further integrated with the base 21 and further descends from the above-mentioned position as a starting point. Then, the tooth cloth 2 is pressed into a predetermined tooth shape.

This method uses the tooth cloth 2 laid on the lower mold 11.
Is strongly restrained at the bottom of the tooth, and the remaining tooth cloth 2 is forcibly pressed and expanded by the second upper mold 20b having a protruding shape. As a result, the tooth cloth 2 is relatively positioned at the bottom of the tooth. And more at the apex.
In addition, at the time of this molding, rosin or a phenol resin is applied to the upper and lower mold surfaces, and the molding effect can be made more effective. Finally, by the molding method according to the present invention described above. A method for manufacturing the toothed belt 1 according to the present invention using the prepared tooth cloth 2 will be described in detail with reference to FIG.

That is, a tooth cloth having a predetermined width and a predetermined length formed by the above-described method of forming the tooth cloth 2 is wound around a grooved mold 30 shown in FIG. Lock. Alternatively, the molded tooth cloth 2 having a predetermined length is formed into a cylindrical shape by heat fusion or a sewing machine joint in advance, and the cylindrical tooth cloth 2 is fitted into the outer periphery of the grooved mold 30.

The tooth cloth 2 is coated on the outer periphery of the grooved mold 30 by using any of the above-mentioned methods, and the core wire 4 is spirally wound thereunder under a constant tension. The rubber sheet 6 is wound to form a preform.
This is shown in the perspective view of FIG.

The preform thus obtained is covered with release paper, covered with a rubber jacket, inserted into a vulcanizer, and heated and pressed to produce a predetermined belt sleeve.
The obtained belt sleeve is finished into a toothed belt having a predetermined width using a belt width cutting device. The above is the method of manufacturing the toothed belt 1 according to the present invention.

Embodiment 1 Hereinafter, an embodiment will be specifically described.

A rubber sheet having the composition shown in Table 1 was used as a rubber sheet constituting the preformed body according to the present invention, a double-sided twill woven cloth shown in Table 2 was used as a tooth cloth, and a core wire was used as a core wire. , Table 3
The E glass core wire shown in FIG.

The grooved mold has 100 teeth S8.
A press mold for pre-molding the tooth cloth according to the present invention using a grooved mold having an M-shaped profile formed in the circumferential direction of the outer peripheral surface thereof is provided with a S8M tooth-shaped tooth portion and a tooth groove portion alternately. An engraved lower mold and a two-stage press mold having a configuration in which a second upper mold was incorporated in a first upper mold disposed on the upper mold were used. In this press die, a second upper die is mounted on the first upper die so as to be vertically movable.

The operation of the press die is as follows. First, the first upper die abuts on the lower die, is positioned appropriately, and firmly fixes the bottom of the tooth cloth to the lower die. Thereafter, the second upper mold movably mounted on the first upper mold is integrated with the base and guided by a guide structure (not shown) provided on the first upper mold. And operates to press and expand the remaining tooth cloth 2. The above operation was controlled using a pneumatic actuator, a pressure sensor, a temperature sensor, a positioning sensor, and a sequential program (not shown).

The tooth cloth according to the present invention is preliminarily molded by the press mold under the following conditions. That is, the pressing temperature is 100 ° C., and the pressing pressure is 0.8 MPa
And the molding time was 7 minutes.

A tooth cloth having a predetermined width and a predetermined length formed by the above-described method is wrapped around a grooved mold, and both ends thereof are locked with a rubber tape, and a core shown in Table 3 is spirally wound thereon. After spinning, a rubber sheet shown in Table 1 was wound and laminated from above the core wire.

Further, a release paper is put on the preform, a jacket is put on it, and the preform is inserted into a vulcanizing can.
The mixture was vulcanized under the conditions of 0.8 ° C. and 45 ° C. for 45 minutes to obtain a predetermined belt sleeve.

After cooling, the belt sleeve is cut to a predetermined width to form a toothed belt, and the cut side surface is imaged using a Keyence microscope (VH-6300) to form a thread for the tooth cloth. The density was evaluated. Further, the durability performance of the toothed belt thus produced was evaluated using a predetermined bench running test machine.

The toothed belt used for this evaluation was 150S
8M800 (belt width: 15 mm, S8M tooth profile, belt length: 800 mm), a biaxial running tester having 24 teeth was used as a testing machine, and the running conditions were a rotation speed of 3600 rpm.
m, load horsepower was 8 kw.

Comparative Example 1 The same constituent materials (tooth cloth, tooth rubber, core wire) used for the toothed belt of Comparative Example 1 were used as in Example 1 of the present invention. The method and the method for manufacturing the toothed belt used the first method described above.

That is, the tooth cloth is not subjected to any preliminary molding, and the tooth cloth, the core wire, and the rubber sheet are sequentially coated on the grooved mold according to the conventional process, and the rubber at the time of heating and pressing is coated. A method of forming and manufacturing by flow force was used.

Comparative Example 2 The same materials (teeth cloth, tooth rubber, core wire) used for the toothed belt of Comparative Example 2 were used as in Example 1 of the present invention. The third method described above was used for the method and the method for manufacturing the toothed belt.

That is, using a conventional press die having one upper surface and one lower surface, the tooth cloth is preliminarily molded with the tooth cloth, and the toothed belt is thereafter formed using this tooth cloth in the same manner as in the embodiment. Was manufactured.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

Table 4 below shows the yarn density and running test results of the tooth cloth evaluated using the toothed belts according to the examples and comparative examples.

[0059]

[Table 4]

As shown in Table 4, the toothed belt produced by using the method for forming a tooth cloth and the method for manufacturing a toothed belt according to the present invention has a lower thread density at the tooth bottom than at the tooth top. About 25
The result is a finer percentage. On the other hand, in the toothed belt of Comparative Example 1, on the contrary, the density was reduced by about 11%. Similarly, the result of Comparative Example 2 was about 2% densified.

Further, the results of the bench running tester show that the durable life was 300 to 350 hours in the examples, 84 to 104 hours in Comparative Example 1, and 13 to 13 hours in Comparative Example 2.
The endurance time was 0 to 150 hours.

As described above, the toothed belt according to the present invention
Because the tooth cloth at the bottom of the tooth is finer than other parts and the durability is improved, the bending stress acting on the tooth bottom repeatedly received on the toothed pulley can be reduced by the flexibility (low elasticity) of the tooth cloth. Coefficient) is optimally absorbed. As a result, the toothed belt of the present invention has an excellent effect of suppressing the generation of cracks at the root of the toothed belt.

[0063]

According to the first aspect of the present invention, the occurrence of cracks at the base of the tooth is suppressed, thereby enabling the use of a toothed belt having excellent durability.

According to the second aspect of the present invention, cracks at the root of the toothed belt are suppressed at the root of the toothed belt, and at the root of the tooth, the rigidity of the tooth at the root is increased by increasing the density of the cloth. This has an excellent effect of suppressing deformation of the entire tooth portion.

According to the third aspect of the present invention, there is an effect that it is possible to manufacture a tooth cloth used for a toothed belt that suppresses the generation of a tooth root crack.

According to the fourth aspect of the present invention, there is an effect that the production of the tooth cloth used for the toothed belt which suppresses the generation of the tooth root crack can be made easy and accurate.

The fifth aspect of the present invention has the effect of enabling the manufacture of a toothed belt which suppresses the generation of cracks at the root.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a toothed belt according to the present invention.

FIG. 2 is a longitudinal sectional view showing the yarn density of the tooth cloth according to the present invention.

3A and 3B are schematic diagrams showing a method of forming a tooth cloth according to the present invention, wherein FIG. 3A shows a state in which the tooth cloth is laid, and FIG. (C) shows a state where the second upper mold expands the tooth cloth into the tooth space.

4A and 4B are schematic diagrams showing a method of forming a tooth cloth according to a conventional example, wherein FIG. 4A shows a state in which the tooth cloth is laid, and FIG. 4B shows an upper mold pressing the tooth cloth downward in a lump. (C) shows a mold completion state.

FIG. 5 is a schematic view showing a method for manufacturing a toothed belt according to the present invention.

FIG. 6 is a longitudinal sectional view of a toothed belt according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toothed belt 2 Tooth cloth 2a Warp 2b Weft 3 Teeth 4 Cord 5 Back 6 Rubber sheet 7 Preform 10 Upper mold 11 Lower mold 20 Upper mold 20a First upper mold 20b Second upper mold Mold 21 base 30 grooved mold

Claims (5)

[Claims] In a toothed belt in which a plurality of teeth arranged in a longitudinal direction are covered with a tooth cloth, a longitudinal density of a warp woven in a belt width direction of the tooth cloth is smaller than a density of a tooth crest. A toothed belt characterized in that the density of the tooth bottom is fine. 2. The ratio of the longitudinal density of the warp at the bottom of the tooth to the longitudinal density of the warp at the top of the tooth is 1.05: 1 to 1.4:
2. The toothed belt according to claim 1, wherein 3. A method for molding a tooth cloth used for a toothed belt in which a plurality of teeth arranged in a longitudinal direction is covered with a tooth cloth, wherein the teeth are formed in a lower mold in which tooth parts and tooth groove parts are alternately engraved. After laying a cloth, the first upper mold is brought into contact with the laid tooth cloth, the tooth cloth is pressed and fixed between the lower die and the tooth bottom of the tooth cloth is molded in a non-stretched state. The second upper mold that moves in coordination with the first upper mold is brought into contact with the tooth cloth in a protruding state, and the tooth cloth is pressed and tightened in the tooth groove of the lower mold, and the crest of the tooth cloth is formed. In a stretched state. 4. The tooth according to claim 3, wherein the second projecting upper mold is mounted on the first upper mold and comes into contact with and separates from the lower mold using the first upper mold as a guide. Cloth molding method. 5. A method of manufacturing a toothed belt in which a plurality of teeth arranged in a longitudinal direction are covered with a tooth cloth, the tooth cloth is laid in a lower mold in which tooth parts and tooth grooves are engraved alternately.
After the tooth cloth is pressed and fixed between the lower mold and the first upper mold to mold the bottom of the tooth cloth in a non-stretched state, the second cloth moves in cooperation with the first upper mold. The upper die is brought into contact with the tooth cloth in a protruding state, and the tooth cloth is pressed and tensioned in the tooth groove portion of the lower die to produce a tooth cloth in which the tooth crests of the tooth cloth are molded in an extended state. The molded tooth cloth is placed on the outer peripheral surface of the grooved mold, and a core wire is spirally wound thereon, and an unvulcanized rubber sheet is further wound thereon to form a preform and then vulcanized. Producing a belt sleeve from the obtained belt sleeve, and finishing the obtained belt sleeve into a toothed belt having a predetermined width.