JP2002174301A - Method of manufacturing for transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing for a transmission belt superior in durability and suppressing tension deterioration over laps of time. SOLUTION: This method of manufacturing for the transmission belt is provided with a canvass material setting a process of covering a canvass material 10 applied with adhesive treatment on a cylindrical metal mold, a core wire material setting a process of tensionally winding a core wire material on the canvass material 10 covered on the cylindrical metal mold directly or via a rubber layer, a rubber setting process of forming a layer of an unvulcanized rubber material on the core wire material wrapped on the canvass material 10, and a vulcanization forming process of heating and pressurizing the canvass material 10, the core wire material, and the unvulcanized rubber material set on the cylindrical metal mold and combining them. A canvass material pre- compressing process of pre-compressing the canvass material 10 applied with the adhesive treatment is provided before the canvass material setting process, or after the canvass material setting process and before the core wire material setting process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method of manufacturing a power transmission belt.

[0002]

2. Description of the Related Art In automobiles and other general industrial machines, power transmission belts are widely used as means for transmitting power. Such a transmission belt includes a toothed belt that transmits power by meshing between belt teeth and a pulley groove, and a V-type belt that transmits power by friction between a belt surface and a pulley surface.
Belt and V-ribbed belt.

[0003]

By the way, the failure modes of the toothed belt are roughly divided into tooth missing, cut, and rubber back crack. It is considered that one of the causes of the missing tooth is a decrease in the tension of the toothed belt over time. That is, it is ideal that the toothed belt travels with the set tension when it is wound around the pulley as the effective tension. However, even if the toothed belt is set with the ideal tension, the belt is run for a certain period of time or left unattended. When this is done, the tension is reduced, and as a result, more stress is applied to the belt teeth than designed, resulting in chipping.

[0004] When the tension of the toothed belt decreases significantly over time, poor meshing may occur and teeth may be skipped.

Further, in frictional transmission of a V-belt or the like, a decrease in tension of the belt over time causes a transmission failure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a power transmission belt which is excellent in durability by preventing a decrease in tension over time. .

[0007]

SUMMARY OF THE INVENTION A method of manufacturing a power transmission belt includes a canvas material setting step of covering a canvas material having been subjected to an adhesive treatment such as gluing on a cylindrical mold, and directly or on the canvas material. A core wire setting step of spirally winding a core wire while applying a constant tension through an unvulcanized rubber sheet, a rubber material setting step of winding an unvulcanized rubber sheet material on the core wire, and these materials Vulcanization molding step of placing a cylindrical mold in which is set in a vulcanizing can and heating and pressurizing the same.

[0008] Although the raw fabric of the canvas material used in the production of the power transmission belt has elasticity in the thickness direction, the canvas material which has been subjected to an adhesive treatment with rubber glue or the like contains an adhesive component, so that heat is generated. In addition, the elasticity is not developed until the adhesive component begins to flow. Therefore, even when the core wire is wound on the canvas material while applying tension in the core wire setting step, the canvas material is slightly compressed and deformed in the thickness direction, but the adhesive component contained in the canvas material in the vulcanization molding step is not deformed. When heated and starts flowing, the canvas material is easily compressed in its thickness direction, and the tension of the core wire wound thereon is reduced. When this is remarkable, the core wire embedded in the rubber composite molded on the cylindrical mold after the vulcanization molding step is in a completely released state. The inventor of the present invention has found that the dimensional stability of the belt is reduced by embedding the core wire in a rubber composite vulcanized and molded on a cylindrical mold in a state where the tension is weakened or in an open state, thereby reducing the dimensional stability of the belt. The inventors have found that the tension of the belt decreases over time, and have arrived at the present invention.

Specifically, the present invention provides a canvas material setting step of covering a canvas material having been subjected to an adhesive treatment on a cylindrical mold, and directly or rubberly attaching the canvas material covered on the cylindrical mold. A core wire setting step of tensioning and winding the core wire through the layer; a rubber material setting step of forming a layer of unvulcanized rubber material on the core wire wound on the canvas material; Vulcanization molding step of heating and pressurizing the canvas material, core wire and unvulcanized rubber material set in the mold, and vulcanization molding process comprising: Alternatively, after the canvas material setting step and before the core wire material setting step, a canvas material pre-compression step of pre-compressing the bonded canvas material is provided.

According to such a method of manufacturing a power transmission belt, even if the adhesive component contained in the canvas material is heated in the vulcanization forming step and starts to flow, the canvas material is pre-compressed, so that the canvas is pre-compressed. Since the compressive deformation in the thickness direction of the material becomes small, the tension of the core wire is maintained without being weakened, and the transmission belt to be manufactured has high dimensional stability. The decrease in the tension of the belt over time is suppressed, and the durability of the belt becomes excellent.

Here, the canvas material is a woven fabric composed of cotton, rayon, polyester (PET) fiber, nylon fiber, aramid fiber, a woven fabric composed of a plurality of fibers selected from these fibers, and the like. And it is not particularly limited. The fabric structure of the canvas material is plain fabric, twill fabric,
It is not particularly limited, such as satin fabric.

[0012] Adhesion treatment of the canvas material includes RFL treatment of dipping the canvas material in resorcinol-formalin latex (RFL) and heating and drying, soaking treatment of dipping the canvas material in rubber paste and heating and drying, There is no particular limitation on the coating treatment for coating the material surface, the combination thereof, and the like.

The core wire is a polyester (PET) fiber,
It is made of twisted yarn or braid made of polyvinyl alcohol (PVA) fiber, polyethylene naphthalate (PEN) fiber, aramid fiber, glass fiber, metal fiber, or the like, and is not particularly limited. Further, the core wire is usually subjected to an adhesive treatment using resorcinol / formalin / latex (RFL), rubber glue or the like.

Unvulcanized rubber materials include natural rubber (NR), styrene-butadiene rubber (SBR), and isoprene rubber (I
R), butyl rubber (IIR), nitrile rubber (NB
R), hydrogenated nitrile rubber (H-NBR), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), ethylene-propylene rubber (EPM), ethylene-propylene-diene-terpolymer rubber (EP
DM), a rubber composition obtained by adding a reinforcing agent such as carbon black or silica and other rubber chemicals to raw rubber such as fluororubber, and is not particularly limited.

[0015] The transmission belt to be subjected to the manufacturing method of the present invention includes a toothed belt for transmitting power by meshing transmission, a V-belt, V-ribbed belt for transmitting power by friction transmission, and the like. There is no particular limitation on the tension member of the high-load transmission V-belt or the like, which is locked with. However, the present invention has a particularly remarkable effect when applied to the production of a toothed belt whose belt tooth side surface is covered with canvas.

In the manufacture of the toothed belt, a cylindrical mold is generally used in which belt tooth forming grooves extending in the axial direction on the mold surface are provided at a predetermined pitch in the circumferential direction. Then, the canvas material, the core wire and the unvulcanized rubber material are set in the cylindrical mold, and by heating and pressurizing them, the unvulcanized rubber flows into the belt tooth forming groove while pressing the canvas material. To form a belt tooth, and a toothed belt whose belt tooth side surface is covered with canvas is manufactured (press-fitting molding method). Therefore, in manufacturing the toothed belt, a canvas material having elasticity in the direction corresponding to the belt longitudinal direction and having high elasticity in the thickness direction is usually used. Therefore, in a toothed belt, there is a strong tendency that the core wire is buried in a state where the tension is weakened or released in a rubber composite vulcanized and formed on a cylindrical mold, and in particular, the belt over time Tension reduction is likely to occur. And, as described above, if the tension of the toothed belt decreases over time, excessive stress acts on the belt teeth, causing chipping or tooth skipping due to poor meshing. Becomes However, according to the manufacturing method of the present invention, the decrease in tension over time is effectively suppressed, and such a failure as tooth missing or tooth skipping is suppressed.

It has also been known that wear of the canvas material on the side and bottom surfaces of teeth leads to tooth chipping. However, by pre-compressing the canvas material at the time of manufacture, the molded toothed belt is formed. The canvas covering the belt tooth surface has almost no elasticity, which results in the formation of highly rigid belt teeth, so that the canvas part on the tooth side and the tooth bottom has high wear resistance, Also from this point, chipping is suppressed.

Further, the canvas covering the tooth side surface of the toothed belt undergoes compression plastic deformation during use of the belt, which also causes one of the causes of a decrease in tension over time. Sometimes by pre-compressing the canvas material,
Such compressive plastic deformation is small, and from this point, a decrease in tension over time is suppressed.

The present invention is also effective in a case where a plurality of bonded canvas materials are put on a cylindrical mold so as to be stacked in the canvas material setting step. When a plurality of canvas materials are stacked and covered on a cylindrical mold, the thickness of the canvas material layer increases, so that the distance over which the canvas material can be compressed in the vulcanization molding process also increases. This is because the pre-compression reduces the distance, thereby preventing the tension of the core wire from weakening. In this case, in the canvas material pre-compression step, a plurality of canvas materials may be pre-compressed in a stacked manner or individually.

[0020]

As described above, according to the method for manufacturing a power transmission belt of the present invention, even when the adhesive component contained in the canvas material is heated during the vulcanization molding step and starts to flow, the canvas material is produced. Since the pre-compression reduces the compressive deformation in the thickness direction of the canvas material, the tension of the core wire is maintained without being weakened. The stability is achieved, the reduction in the tension of the belt over time is suppressed, and a transmission belt having excellent durability can be obtained.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a toothed belt according to an embodiment of the present invention will be described below in the order of steps. The toothed belt manufactured has a belt tooth pitch of 14 mm used in general industrial machines.

<Material Preparation Step> As a material for manufacturing the toothed belt, two nylon fiber canvas materials, a glass fiber core wire, and an unvulcanized rubber composition of chloroprene rubber (CR) are used. An unvulcanized rubber sheet material is prepared.

Each canvas material is a nylon twisted yarn in which a yarn corresponding to the belt longitudinal direction is crimped so as to have elasticity in a direction corresponding to the belt longitudinal direction, and a yarn corresponding to the belt width direction is a nylon twisted yarn. And a twill fabric composed of Further, this canvas material is subjected to a soaking process of dipping in dilute rubber paste and heating and drying, and a coating process of coating rubber paste on a surface corresponding to the inside of the belt.

The core wire is subjected to RFL bonding treatment in which the glass fiber bundle is immersed in RFL and dried by heating, and a plurality of ply-twisted ply-twisted yarns are collected, and then these are ply-twisted in the opposite direction to the ply-twist. Shall be done. At this time, one having an S twist and one having a Z twist are prepared.

The unvulcanized rubber sheet is kneaded by feeding chloroprene rubber (CR) as a raw rubber into a kneader such as a Banbury mixer, and kneading the mixture with carbon black as a reinforcing agent, a vulcanizing agent, and a vulcanizing agent. It is assumed that a rubber composition mass obtained by adding a rubber chemical such as an accelerator and further kneading them is processed into a long sheet shape using a calendar roll or the like.

<Pre-compressing step of canvas material> Each of the two canvas materials is sandwiched between a pair of metal flat plates, and a spacer is interposed between the metal flat plates so that the thickness of the canvas material is uniform. Pre-compression of the canvas material under pressure. At this time, if the original fabric of the canvas material remains intact, it will be elastically restored even if it is pre-compressed. However, as shown in FIG. 1, the rubber component (soaking rubber 12, coating rubber 12, By the operation of 13), the nylon fiber yarns 11, 11,... Are maintained in a compressed state, and the stretchability of the canvas material 10 is maintained.
In addition, the thickness of the canvas material in the thickness direction increases.

It is preferable that the compression of the canvas material is performed until the thickness of the canvas material becomes substantially equal to the thickness of the canvas when the toothed belt is finally completed. By doing so, even when the canvas material is heated in the subsequent vulcanization molding step, the canvas material is reliably prevented from being compressed and the tension of the core wire is reduced or the tension is released. is there.

<Process of setting canvas material> Each of the pre-compressed canvas materials is machined into a tubular shape by sewing the both ends of the canvas material together with a sewing machine. At this time, the crimped nylon twisted yarn is extended in the circumferential direction.

Then, the two canvas members are overlapped on a cylindrical mold for forming a toothed belt in which belt tooth forming grooves extending in the axial direction are provided on the surface of the mold at a predetermined pitch in the circumferential direction. Cover. At this time, the side of each canvas material coated with the glue rubber is positioned outside.

<Core Wire Setting Step> A pair of S-twisted and Z-twisted core wires are wound at a predetermined pitch from a pair of S-twisted and Z-twisted core materials on the two canvas materials covered by the cylindrical mold. At this time, the winding is performed while tension is applied to both the core wires so that the wound core wire keeps the tensioned state.

<Rubber material setting step> An unvulcanized rubber sheet material is wound several times over a core wire layer formed by winding a core wire in a double spiral.

As described above, as shown in FIG.
The double canvas material 10, 1 is sequentially placed in the cylindrical mold 1 from the mold side.
0, the core wire material 20 and the unvulcanized rubber sheet material 30 are set.

<Vulcanization molding step> A release paper is adhered to the outermost unvulcanized rubber sheet material surface, and a cylindrical mold in which the canvas material, the core wire material and the unvulcanized rubber sheet material are set is placed in a vulcanized can. Get in,
These materials are compounded at a predetermined temperature and pressure for a predetermined time. At this time, as shown in FIG. 2B, the unvulcanized rubber flows into the belt tooth forming groove 2 while pressing the canvas materials 10 and 10 to form belt teeth. Since 10 is pre-compressed, the canvas material 10, 10
Is not greatly compressed and deformed, and the tension of the core wire 20 is not weakened.
The zero portion also has a small thickness and a high tooth portion rigidity.

If the canvas is not pre-compressed, as shown in FIG. 3 (a), the cylindrical mold 1 has the thick canvas 10a, 10a, the core wire 20a and the unvulcanized rubber. The sheet material 30a is set, and when these are combined with a predetermined temperature and pressure for a predetermined time, the rubber components contained in the canvas materials 10a, 10a flow, and the canvas materials 10a, 10a are easily compressed. As shown in FIG. 3 (b), the canvas material 10a, 10a portion sandwiched between the cylindrical mold 1 and the core wire 20a undergoes a large compressive deformation, whereby the tension of the core wire 20a is reduced, and As the vulcanized rubber flows into the belt tooth forming groove 2, the core wire 20 a is buried in the rubber composite in a state of falling into the belt tooth forming groove 2 side. For this reason, the tension of the belt is greatly reduced with time, and tooth skipping due to excessive stress applied to the belt teeth or poor meshing easily occurs. Further, canvas materials 10a, 10a for covering the belt tooth side surface.
Although they are stretched and their thickness is reduced, a certain thickness is maintained, so that they have relatively high elasticity and low wear resistance. For this reason, the canvas is worn early on the side surfaces and the bottom surface of the teeth, and the chipping is likely to occur starting from that.

<Demolding and Back Polishing Step> A cylindrical mold having a cylindrical rubber composite formed on the mold is taken out of the vulcanizing can, and the rubber composite is removed from the cylindrical mold.

Then, the outer peripheral surface is polished so that the thickness of the rubber composite becomes a predetermined thickness, thereby removing release paper and excess rubber.

<Width cutting step> A toothed belt 40 having belt teeth provided at a predetermined pitch in the longitudinal direction as shown in FIG. 4 is manufactured by cutting the rubber composite whose outer peripheral surface is polished into a predetermined width. Will be done.

The toothed belt 40 has a tooth rubber portion 41 which forms the belt teeth and a back rubber portion 4 which forms the belt rear surface.
2 form a belt body. The back rubber portion 42 of the belt main body is provided with a double spiral S-twisted and Z-twisted core wire 43 so as to form a pitch in the belt width direction. Further, the belt tooth side surface of the belt body is covered with two layers of canvas 44,44.

According to the method for manufacturing a toothed belt as described above, even if the rubber component of the adhesive contained in the canvas material is heated and starts to flow during the vulcanization molding step, the canvas material is pre-compressed. By doing so, the compressive deformation in the thickness direction of the canvas material is reduced, thereby maintaining the tension state of the core wire without weakening, and the toothed belt manufactured has high dimensional stability As a result, a decrease in the tension of the belt over time is suppressed, tooth skipping due to excessive stress acting on the belt teeth or tooth skipping due to poor meshing does not easily occur, and the durability is excellent.

In the manufacture of the toothed belt according to this embodiment,
Since the canvas material has elasticity in the circumferential direction and therefore has high elasticity in the thickness direction, and since two canvases are used, the above-mentioned effect by pre-compressing the canvas is as follows. It will be very noticeable.

Also, by pre-compressing the canvas material,
Compressive plastic deformation that occurs during use of the belt is reduced, and this also suppresses a decrease in tension over time.

Furthermore, by pre-compressing the canvas material, the canvas covering the belt tooth surface of the formed toothed belt has high hardness and little elasticity, and the formed belt teeth have high rigidity. In addition, the wear resistance of the tooth side surface and the tooth bottom surface becomes high, and from this point, the tooth chipping is also suppressed.

(Other Embodiments) In the above embodiment,
A nylon fabric was used as the canvas material, but the fabric is not particularly limited to this, and a woven fabric composed of cotton, rayon, polyester (PET) fiber, aramid fiber,
A woven fabric or the like composed of a plurality of fibers selected from these fibers may be used. In the above embodiment, the fabric structure of the canvas material is a twill fabric. However, the present invention is not particularly limited to this, and a plain fabric, a satin fabric, or the like may be used.

Further, in the above-described embodiment, two canvas materials are used in piles, but the present invention is not limited to this, and one canvas material may be used.

Further, in the above embodiment, the soaking treatment with the rubber paste and the coating treatment with the rubber paste were performed as the bonding treatment of the canvas material. However, the present invention is not particularly limited thereto. Well,
Only the RFL process may be performed, or only the process using rubber glue may be performed.

Further, in the above embodiment, a glass fiber is used as the core wire. However, the present invention is not limited to this, and polyester (PET) fiber, polyvinyl alcohol (PVA) fiber, polyethylene naphthalate ( (PEN) fiber, aramid fiber, metal fiber, or the like, and may be formed of a twisted yarn or braid.

In the above embodiment, the unvulcanized rubber sheet is made of chloroprene rubber (CR). However, the present invention is not limited to this. Natural rubber (N
R), styrene-butadiene rubber (SBR), isoprene rubber (IR), butyl rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), chlorosulfonated polyethylene rubber (CSM), ethylene-propylene Rubber (EPM), ethylene-propylene-
It may be made of diene-terpolymer rubber (EPDM) or fluoro rubber.

In the above-described embodiment, the production of the toothed belt is intended. However, the present invention is not limited to this. Friction transmission belts such as V-belts and V-ribbed belts and blocks are arranged at a predetermined pitch in the longitudinal direction. It may also be used to produce a locked high-load transmission V-belt tension member.

In the above-described embodiment, the press-fit molding method of forming the belt teeth while pressing the canvas material against the unvulcanized rubber in the vulcanization molding step by using the stretchable canvas material is employed. The present invention is not limited to this, and an embossing method of preforming a non-stretchable canvas material along the surface of the mold may be employed. In this case, the pre-compression of the canvas material may be performed before or after setting the canvas material in the cylindrical mold.

Further, in the above embodiment, the pre-compression treatment of the canvas material is performed by pressing the canvas material between a pair of metal flat plates. However, the present invention is not particularly limited thereto. The pre-compression process may be performed by passing through a roll processing machine such as the one described above.

In the above embodiment, the canvas material pre-compression step is provided before the canvas material setting step. However, the present invention is not particularly limited to this, and the canvas material pre-compression step is provided after the canvas material setting step and before the core wire material setting step. It may be. That is, after the canvas material is set in the cylindrical mold, the pre-compression process may be performed on the mold.

[0052]

[Example] (Belt for test evaluation)-Example-14 m belt tooth pitch manufactured by the method of the above embodiment
m, a toothed belt having a belt width of 12 mm was used as an example. Each canvas material was 1.1 m thick instead of 1.7 mm thick.
m before use.

Comparative Example A toothed belt manufactured by the same method as the example except that the canvas was not pre-compressed was used as a comparative example.

(Test Evaluation 1) <Test Evaluation Method> As shown in FIG. 5, each of the toothed belts 40 of the embodiment and the comparative example was formed by a driving pulley 51 having 22 teeth and a driven pulley 52 having 45 teeth. , And a constant load of 1765 N is applied to the driven pulley 52 in a direction opposite to the driven pulley 52 side. m
And pull the drive pulley 51 at 1557 rpm
And the belt was run for 24 hours. Then, the change of the tension with time of each belt at that time was measured. The ambient temperature of the belt was set to 60 ° C.

<Test Evaluation Results> FIG. 6 shows the belt running time, the tension holding ratio when the set tension is 100%, and
Shows the relationship.

According to FIG. 6, in the comparative example, the tension decreases to about 70% at the beginning of traveling, and thereafter changes at that level, whereas in the example, the tension decreases at the beginning of traveling but 90% of the set tension. It can be seen that it has been held, and since then it has been at that level. This is because, in the comparative example, the tension of the core wire is weakened and the tension is released in the vulcanization molding process, and the compression plastic deformation of the canvas during belt running occurs, whereas in the example, the canvas material is pre-compressed during the belt manufacturing. This is considered to be because, by doing so, the weakening and release of the tension of the core wire and the compression plastic deformation of the canvas were suppressed.

(Test Evaluation 2) <Test Evaluation Method> As shown in FIG. 7, each of the toothed belts of the example and the comparative example was driven by a drive pulley 51 having 22 teeth.
And a driven pulley 52 having 45 teeth, a constant load of 1765 N is applied to the driven pulley 52 in the opposite direction to the driven pulley 52 side, and 147.1 N. m, and the driving pulley 51 was rotated at 1557 rpm to run the belt. Then, the running time until tooth chipping occurred in each belt at that time was measured. The same measurement was performed by applying a load of 117.7 N · m to the driven pulley 52. <Test Evaluation Results> FIG. 8 shows the relationship between the toothless life and the load applied to the driven pulley.

According to FIG. 8, in both the embodiment and the comparative example, the smaller the load on the driven pulley is common in that the toothless life is longer, but if the load applied to the driven pulley is the same, Example 2 has about 2 tooth missing life compared with Comparative Example.
It turns out that it is twice as long. This is considered to be because, as described in Test Evaluation 1, in the example, the set tension was maintained at 90%, and the application of excessive stress to the belt teeth as compared with the comparative example was suppressed. Further, in the embodiment, the canvas covering the belt tooth surface of the formed toothed belt has little elasticity by pre-compressing the canvas material at the time of manufacture, thereby forming a highly rigid belt tooth. Therefore, it is considered that the wear resistance of the tooth side surface and the tooth bottom surface is higher than that of the comparative example, and the tooth chipping is suppressed.

[Brief description of the drawings]

FIG. 1 is an illustration of a canvas material pre-compression step in a method for manufacturing a toothed belt according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a vulcanization molding step in a method for manufacturing a toothed belt according to an embodiment of the present invention.

FIG. 3 is an explanatory view of a vulcanization molding step in a method for manufacturing a toothed belt according to a conventional example.

FIG. 4 is a perspective view of a toothed belt.

FIG. 5 is a layout diagram of a traveling test machine used in test evaluation 1.

FIG. 6 is a graph showing a relationship between a belt running time and a tension holding ratio when a set tension is set to 100%.

FIG. 7 is a layout diagram of a traveling test machine used in test evaluation 2.

FIG. 8 is a graph showing a relationship between a toothless life and a load applied to a driven pulley.

[Explanation of symbols]

 Reference Signs List 1 cylindrical mold 2 belt tooth forming groove 10, 10a canvas material 11 nylon fiber thread 12 soaking rubber 13 coating rubber 20, 20a core wire material 30, 30a unvulcanized rubber sheet material 40 toothed belt 41 tooth rubber part 42 back rubber Part 43 core wire 44 canvas 51 drive pulley 52 driven pulley

Claims (3)

[Claims] 1. A canvas material setting step for covering a cylindrical mold with a bonded canvas material, and a core wire is directly or via a rubber layer on the canvas material covered on the cylindrical mold. A core wire setting step of tensioning and winding; a rubber material setting step of forming an unvulcanized rubber layer on the core wire wound on the canvas; and a canvas set in the cylindrical mold Vulcanization molding step of heating and pressing the core wire and the unvulcanized rubber material to composite them, and wherein the vulcanization molding step comprises: before the canvas material setting step, or after the canvas material setting step. The method of manufacturing a power transmission belt according to claim 1, further comprising, before the core wire setting step, a canvas material pre-compression step of pre-compressing the bonded canvas material. 2. The method according to claim 1, wherein the transmission belt is a toothed belt whose belt tooth side surface is covered with canvas. 3. In the canvas material setting step, the cylindrical mold is covered with a plurality of bonded canvas materials so as to be stacked, and in the canvas material pre-compression step, any one of the plurality of canvas materials is used. 3. The method according to claim 1, further comprising:
3. The method for manufacturing a power transmission belt according to item 1.