JP2004066475A - Method for manufacturing toothed belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a toothed belt which can improve a jumping performance and durability by suppressing occurrence of an allophone as compared with a prior art. <P>SOLUTION: The method for manufacturing the toothed belt includes the steps of arranging an extendible canvas 2 on a toothed surface of a mold 1 having a tooth shape, fixing a resin film 3 extendible in synchronism with the canvas 2 fixed to the surface side of the canvas 2 in contact with the mold 1 and set to a higher melting point than a belt body material 5, and molding the belt body material 5 of a flowable state at the melting point or lower by the mold 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a toothed belt for power transmission and conveyance.
[0002]
[Prior art]
Conventionally, as shown in FIG. 4, a toothed belt 11 has been used for power transmission, conveyance, and the like.
[0003]
As shown in FIG. 5, the toothed belt 11 has a tooth portion and a tooth bottom portion engaged with a pulley or the like, and is manufactured by supplying a raw material 13 (resin or elastomer) to a molding die 12 having a tooth shape. Is done. On the tooth profile surface of the molding die 12, a canvas 14 having elasticity is disposed in advance.
[0004]
By the way, the stretchable canvas 14 disposed on the tooth profile surface is subjected to a texture filling treatment with latex, RFL, rubber glue, or the like. In some cases, the raw material 13 partially exudes to the surface side of the belt tooth portion from a portion where the sealing was insufficient when the texture was expanded and the texture was widened. In the figure, reference numeral 15 denotes a bag rubber for molding.
[0005]
However, when the resin or the elastomer passes through the canvas 14 and is exposed on the surface side of the belt tooth portion, the difference is caused by an unbalanced state in which the exposed portion and the non-exposed portion (the canvas 14 covers the belt tooth surface) are mixed. There is a problem that sound may be generated.
[0006]
In addition, when the resin or the elastomer is exposed on the surface side of the belt tooth portion, the resin or the elastomer is easily peeled off or dropped off during traveling, so that there is a problem that the jumping performance and the durability are not good.
[0007]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a method for manufacturing a toothed belt that can suppress generation of abnormal noise and improve jumping performance and durability as compared with the related art.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following technical means.
{Circle around (1)} The method of manufacturing a toothed belt according to the present invention comprises disposing an elastic canvas on a tooth profile surface of a molding die having a tooth profile, and synchronizing with the canvas on a surface side of the canvas that contacts the molding die. The resin film that expands and contracts is fixed, and the resin film is set to have a melting point higher than that of the belt body material, and the molding die molds the belt body material in a flowable state below the melting point. It is characterized by.
[0009]
In this method for manufacturing a toothed belt, the resin film that is fixed to the surface of the canvas in contact with the molding die and expands and contracts in synchronism with the canvas is set to have a higher melting point than the raw material of the belt body. Even if the belt body raw material in a possible state passes through the eyes of the canvas, the resin film having a high melting point and not being in a molten state at the time of molding cannot be exceeded. Therefore, the raw material of the belt body does not exude to the tooth side of the belt, and is not exposed to the surface side of the tooth portion of the belt.
[0010]
In addition, the canvas and the resin film pressed by the belt body material flowing during the belt molding are extended in synchronism and extend along the grooves of the molding die, so that the canvas layer and the resin film layer having a substantially uniform thickness are formed. . When the canvas layer serving as the tooth bottom has a uniform thickness, the pitch line is stabilized, and the core wire (cord) is protected, so that the durability is improved.
[0011]
Heating may be started after a belt-shaped raw material, such as a sheet, is deformed to a certain degree and is deformable to a molding die in advance, and may be heated by an extruder or the like in a flowing state (a liquid resin or a molten state). May be supplied to a molding die.
{Circle around (2)} The fluidized belt main body material may pass through the eyes of the canvas and fuse to the resin film.
[0012]
During the belt molding, the resin film softens slightly, and the belt body material that has passed through each eye of the canvas is directly fused to the resin film, so that after cooling, the belt body material, the canvas, and the resin film are mutually strongly bonded. Can be fixed.
{Circle around (3)} A polyetherester resin may be used as the belt body material, and a polyetherester resin film may be used as the resin film.
[0013]
Various resins and elastomers can be used as the material of the belt body and the resin film.However, when the polyetherester resin is used in this way, the thermoplastic elastomer has excellent high-temperature properties and has a high temperature characteristic from a low temperature to a high temperature. Since it exhibits high strength and rubber elasticity, it has a wide operating temperature range, is excellent in vibration absorption, oil and water resistance, and chemical resistance. In addition, due to its low friction coefficient, it has low engagement noise with pulleys and has good durability.
[0014]
In addition, it can be molded by an injection molding machine using a liquid casting resin or an elastomer as a belt body raw material, or can be molded by an extruder using a thermoplastic elastomer.
{Circle around (4)} The outermost layer of the canvas is formed with a phenol resin layer modified with a component containing phenol and / or phenol carboxylic acid having a side chain having an unsaturated bond and a predetermined compound. With this configuration, the adhesiveness between the canvas and the belt body material made of polyetherester resin is excellent.
[0015]
Here, when the latex treatment or the RFL treatment is performed before forming the phenolic resin layer on the canvas, the rubbing between the yarns of the canvas is reduced, which is effective for the abrasion resistance of the canvas.
(5) The core wire is embedded, and the outermost layer of the core wire is a phenol modified with a component containing phenol and / or phenol carboxylic acid having a side chain having an unsaturated bond and a predetermined compound. With such a configuration in which the resin layer is formed, the adhesiveness between the core wire and the belt body material made of the polyetherester resin is excellent. In order to increase the adhesive strength between the core wire (glass fiber or aromatic polyamide fiber) and the belt body, a resorcinol-formaldehyde-latex (RFL) layer may be formed on the core wire as necessary, or resorcinol may be used. An overcoat layer having excellent adhesion to the RFL layer may be further formed on the formaldehyde-latex (RFL) layer.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
As shown in FIGS. 1 and 2, in the method for manufacturing a toothed belt according to this embodiment, a stretchable canvas 2 (tooth cloth) is disposed on a tooth profile surface of a molding die 1 having a tooth profile, and A resin film 3 (functioning as a seal and acting as a barrier) is fixed to the surface of the mold 2 in contact with the molding die 1 in synchronism with the canvas 2. A core wire 4 is arranged outside the canvas 2 with respect to the tooth profile surface of the molding die 1.
[0018]
Incidentally, the melting point of the resin film 3 is set higher than that of the belt body raw material 5. A polyetherester resin was used as the belt body raw material 5, and a polyetherester resin film was used as the resin film 3.
[0019]
The molding die 1 is used to mold the belt body raw material 5 in a flowable state at a temperature equal to or lower than the melting point of the resin film 3, and the texture 6 of the canvas 2 (see FIG. When expanded by the pressure of 5 (see FIG. 3B), the belt body raw material 5 that has passed through between the core wires 4 from the belt back side and oozed from the eyes of the canvas 2 is fused to the resin film 3. I do. In the figure, reference numeral 7 denotes a bag rubber for molding.
[0020]
Specifically, Hytrel (trade name, manufactured by Du Pont-Toray Co., Ltd.) was used as the polyetherester resin as follows.
[0021]
A nylon (trademark) canvas 2 (tooth cloth) having elasticity is disposed on the tooth profile surface of a molding die 1 (molding mold) having a tooth profile. A resin film 3 (Hytrel film) that expands and contracts in synchronism with the canvas 2 is fixed. A core wire 4 (glass cord, aramid cord, etc.) was arranged on the outside of the canvas 2 with respect to the tooth profile surface of the molding die 1. Then, a belt body raw material 5 (Hytrel sheet) in a flowable state at a melting point of the resin film 3 (Hytrel film) or less was heated and pressed by a molding die 1.
[0022]
Next, a method for manufacturing the toothed belt of this embodiment will be described.
[0023]
In this method of manufacturing a toothed belt, a resin film 3 having a higher melting point than the belt body raw material 5 is fixed to the tooth surface side of the canvas 2 (see FIG. 2A), and the canvas 2 is formed from the back side during molding. The belt main body material 5 that has passed through the fold 6 (see FIG. 3) is fused (see FIG. 2B) to prevent the belt main body material 5 from entering the tooth surface (see FIG. 2C).
[0024]
That is, even if the belt body raw material 5 which is in a flowable state at a temperature lower than the melting point of the resin film 3 at the time of molding passes through the weave 6 (see FIG. 3) of the canvas 2 (see FIG. 2B), the resin film 3 fixed to the canvas 2 Since the melting point is set higher than that of the belt body raw material 5, the resin film 3 has a high melting point and cannot exceed the resin film 3 which is not in a molten state during molding (see FIG. 2C).
[0025]
Therefore, since the belt body raw material 5 does not exude to the belt tooth surface side (see FIG. 1), it is not exposed to the surface side of the belt tooth portion, and a portion where the belt body raw material 5 is exposed and a portion where it is not mixed are mixed. There is an advantage that the state does not become unbalanced, the generation of abnormal noise can be suppressed more than before, and the jumping performance and durability performance can be improved.
[0026]
In addition, since a structure of the resin film 3 is laminated on the toothed surface of the fabric 2 of the toothed belt of the manufactured toothed belt, oil, water, etc. from the belt tooth surface side by the resin film 3 layer. Of the belt can be prevented, and the belt has excellent dimensional stability and a long life.
[0027]
Although various resins and elastomers can be used as the belt body material 5, the use of a polyetherester resin has excellent high-temperature characteristics among thermoplastic elastomers, and exhibits high strength from low to high temperatures and rubber elasticity. It has the advantages of a wide operating temperature range, excellent vibration absorption, oil and water resistance, and chemical resistance, as well as low engagement coefficient with the pulley due to its low friction coefficient and good durability.
[0028]
In addition, as the belt main body raw material 5, it is possible to use an injection molding machine using a liquid casting resin or an elastomer, or to use an extruder using a thermoplastic elastomer.
[0029]
【Example】
Next, the configuration of the present invention will be described more specifically.
(Example 1)
A resin film 3 (Hytrel film) having a melting point higher than that of the belt body material 5 (Hytrel sheet) was fixed (laminated) to a nylon (trademark) canvas 2 (tooth cloth) and cut and fused to predetermined dimensions ( Called canvas jacket).
[0030]
The canvas 2 was subjected to a latex treatment and an RFL treatment, and a phenol resin layer having a side chain having an unsaturated bond was formed on the outermost layer. Instead of the phenol resin layer, a phenol resin layer modified with a component containing phenol carboxylic acid and a predetermined compound may be formed.
[0031]
The canvas jacket is put on the tooth profile surface of the outer periphery of the molding die 1 (molding mold) such that the resin film 3 (Hytrel film) is in contact with the molding surface of the molding die 1, and the core wire 4 (glass Cords, aramid cords, etc.) were spirally wound.
[0032]
On the outermost layer of the core wire 4, a phenol resin layer having a side chain having an unsaturated bond was formed. Further, in order to increase the adhesive strength between the core wire and the belt main body, an RFL layer is formed, and thereafter, an overcoat layer having excellent adhesiveness with the RFL layer is formed in advance.
[0033]
A belt body raw material 5 (Hytrel sheet) at room temperature was wound from above the core wire 4 and stopped with an adhesive tape. A release paper was wound around the belt body raw material 5 (Hytrel sheet), fixed with an adhesive tape, inserted into an outer shell, placed in a vulcanizing kettle, and heated and pressed to form a belt slab. The heating temperature was set equal to or higher than the melting point of the belt body raw material 5 (Hytrel sheet) and lower than the melting point of the resin film 3 (Hytrel film). The pressing force and the heating time were set so that the resin body flowed and the belt teeth were completely formed.
[0034]
In other words, the belt body raw material 5 (Hytrel sheet) is pre-arranged in the molding die 1 in the form of an unheated resin sheet together with the canvas 2 and the core wire 4 coated and fixed with the resin film 3, and from room temperature during molding. By heating and pressurizing until the molding temperature is reached, the belt body raw material 5 is plasticized to be in a flowable state and the belt teeth are formed.
[0035]
Then, the resin film 3 (Hitrel film) fixed to the canvas 2 is stretched in synchronization with the extension of the canvas 2 at the time of molding, and when the belt teeth are formed, the canvas 2 covered with the resin film 3 covers the belt tooth surface. Began to form.
[0036]
After the completion of molding, the molding die 1 was immediately cooled with water and cooled to around room temperature. The molding die 1 was removed from the outer shell, and the molded slab was removed from the molding mold by a demolding machine. The back of the molded slab was polished with a slab grinder to remove release paper, and the belt was adjusted to a predetermined belt thickness, and then printed and cut to obtain a toothed belt.
[0037]
The resulting toothed belt has, in order from the surface side of the belt teeth, three resin films, two layers of canvas impregnated with the belt resin 5, and five layers of belt body resin (with core wire 4). That is, the resin film 3 prevents the belt main body raw material 5 from oozing out on the belt tooth surface, and the canvas 2 covered with the resin film 3 is formed on the belt tooth surface.
[0038]
This method has the advantages that it is simple, the production cost is low, and no preforming equipment is required.
(Example 2)
A resin film 3 (Hytrel film) having a melting point higher than that of the belt body raw material 5 (Hytrel sheet) is fixed (laminated) to a nylon (trademark) canvas 2 (tooth cloth), and is preformed by a preforming machine (not shown). The belt tooth surface side was preformed so as to become the Hytrel film 3 (referred to as preformed canvas).
[0039]
The preformed canvas is cut and sewn in accordance with the number of teeth and the tooth width of the molding die 1 (molding mold), and is fitted in accordance with the gear cutting surface on the outer periphery of the molding mold. A core wire 4 (glass cord, aramid cord, etc.) was spirally wound.
[0040]
A belt body raw material 5 (Hytrel sheet) at room temperature was wound from above the core wire 4 and stopped with an adhesive tape. A release paper was wound around the belt body raw material 5 (Hytrel sheet), fixed with an adhesive tape, inserted into an outer shell, placed in a vulcanizing kettle, and heated and pressed to form a belt slab.
[0041]
The heating temperature was set equal to or higher than the melting point of the belt body raw material 5 (Hytrel sheet) and lower than the melting point of the resin film 3 (Hytrel film) to be laminated. The pressing force and the heating time were set so that the resin body flowed and the belt teeth were completely formed.
[0042]
After the completion of molding, the molding die 1 was immediately cooled with water and cooled to around room temperature. The molding die 1 was removed from the outer shell, and the molded slab was removed from the molding mold by a demolding machine. The back of the molded slab was polished with a slab grinder to remove release paper, and the belt was adjusted to a predetermined belt thickness, and then printed and cut to obtain a toothed belt.
[0043]
According to this method, since the canvas 2 and the resin film 3 (Hytrel film) are hardly stretched at the time of molding, variations in the yarn density of the canvas 2, the film thickness of the resin film 3 and the like can be small, and the film thickness can be reduced. There is an advantage that the performance of the product is high and the durability is good.
[0044]
【The invention's effect】
The present invention is configured as described above and has the following effects.
[0045]
Since the raw material of the belt body is not exposed on the surface side of the belt tooth portion, it is possible to provide a method of manufacturing a toothed belt capable of suppressing generation of abnormal noise and improving jumping performance and durability performance as compared with the related art.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part illustrating a toothed belt manufactured by an embodiment of a method for manufacturing a toothed belt according to the present invention.
FIG. 2 is a view for sequentially explaining the manufacturing method of FIG. 1;
FIG. 3 is a plan view illustrating the state of the texture of the canvas.
FIG. 4 is a perspective view illustrating a toothed belt.
FIG. 5 is a view for explaining a conventional method for manufacturing a toothed belt.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Molding die 2 Canvas 3 Resin film 5 Belt body raw material

Claims (5)

A stretchable canvas is disposed on a tooth profile surface of a molding die having a tooth profile, and a resin film that expands and contracts in synchronism with the canvas is fixed to a surface of the canvas in contact with the molding die and the resin A method for producing a toothed belt, characterized in that the film has a melting point higher than that of the belt body raw material, and the molding die is used to mold the belt body raw material in a flowable state at the melting point or lower. 2. The method for manufacturing a toothed belt according to claim 1, wherein the flowed material of the belt body passes through the eyes of the canvas and is fused to the resin film. 3. The method according to claim 1, wherein a polyetherester resin is used as the belt body material, and a polyetherester resin film is used as the resin film. The tooth according to claim 3, wherein a phenol resin layer modified with a component containing phenol and / or phenol carboxylic acid having a side chain having an unsaturated bond and a predetermined compound is formed on the outermost layer of the canvas. Method of manufacturing a belt. The core wire is embedded, and the outermost layer of the core wire includes a phenol resin layer modified with a component containing phenol and / or phenol carboxylic acid having a side chain having an unsaturated bond and a predetermined compound. The method for producing a toothed belt according to claim 3, wherein the belt is formed.

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