KR20040012546A - Toothed belt and method of production thereof - Google Patents

Abstract

PURPOSE: A toothed belt and a manufacturing method thereof are provided to improve jumping performance, durability, and response property, to reduce driving friction, and to prevent abnormal noise. CONSTITUTION: A toothed belt(10) with a toothed surface comprises a belt body made of thermoplastic elastomer(15); a cord(16) embedded in the belt body to function as an extension member; and a cover fabric(12) for covering the toothed surface. A method for manufacturing the toothed belt is composed of steps for forming a preform of thermoplastic elastomer; forming an assembly body by assembling the cover fabric, the cord, and the preform to a mold; pressurizing and heating the assembly body from the outside of the mold; and forming saw teeth on the surface of the assembly body by heating the assembly body from the inside of the mold for the predetermined time over the crystallization temperature and lower than the melting point of the thermoplastic elastomer.

Description

Toothed belt and its manufacturing method {TOOTHED BELT AND METHOD OF PRODUCTION THEREOF}

The present invention relates to a toothed belt made of thermoplastic elastomer, which can be used for power transmission, transportation, and the like.

Conventionally, toothed belts made of rubber (see, for example, Japanese Patent Application Laid-Open No. H11-182632 (see FIGS. 1 and 2, Fig. 1)) or thermosetting polyurethane elastomers have been used. The toothed belt has a bottom and teeth which engage the pulley.

As the functionality of devices using belt mechanisms increases, the jumping resistance, durability, drive resistance degradation, and responsiveness increase the current belt technology (especially the pitch of the teeth). Small cases) cannot be satisfied. In addition, when the resin or elastomer is exposed to the surface side of the tooth, the resin or elastomer easily peels off or falls off during use, resulting in problems such as abnormal noise, undesirable jumping performance, and deterioration in durability.

It is an object of the present invention to have superior jumping resistance, improved durability, reduced driving friction, and improved responsiveness, as compared with the prior art (rubber belt or thermosetting polyurethane elastomer belt), which can prevent abnormal noise. It is to provide a belt attached.

According to the present invention, there is provided a belt body made of thermoplastic elastomer having advantages (elasticity and strength) of both rubber and plastic, a cord acting as a tension member, and a canvas covering the tooth surface of the belt. A belt is provided. The thermoplastic elastomers having copolymers which form hard segments in the crystalline phase and soft segments in the amorphous phase, exhibit rubbery elasticity at room temperature, are made of plastic, and at high temperatures. Can be molded.

Since the toothed belt of the present invention is formed as described above, the resistance to seepage as well as reduced driving friction as well as jumping resistance, durability, responsiveness, and the like compared to conventional rubber belts great.

Here, the material of the canvas may be, for example, nylon, polyester, aramid, cotton, PBO fibers and the like. In addition, the material of the cord may be, for example, polyester, glass fiber, aramid, steel, carbon fiber, PBO fiber and the like.

In addition, the thermoplastic elastomer is preferably a thermoplastic polyether ester elastomer. The thermoplastic polyether ester may comprise a copolymer of an aromatic polyester (crystalline phase (hard segment)) and an aliphatic polyester (amorphous phase (soft segment)). The hard segment may be an aromatic polyester having a high melting point and is excellent in fast crystallization rate, high strength, heat deformation resistance, excellent moldability, chemical stability, and heat aging resistance. In addition, the soft segment may be an aliphatic polyester having a low glass transition point, and is excellent in flexibility, high impact absorption, and low temperature characteristics. In addition, the ratio of hard segments to soft segments of the elastomer can be appropriately taken to take advantage of these properties.

The toothed belt constructed in this way is characterized by quietness, impact resistance, impact resilience, low temperature flexibility, bending strength, environmental resistance (low out gas) and food hygiene. Take advantage of food sanitariness

In addition, a thermoplastic polyurethane elastomer may be used as the thermoplastic elastomer used for the toothed belt. The thermoplastic polyurethane elastomer includes a polyester type and a polyether type, and includes a soft segment and a hard segment. Soft segments include polyethylene adipate, polybutylene adipate, other adipate esters (ADP), polycaprolactone (PCL), polycarbonate (PC), or other aliphatic polyester diols diols), polytetramethylene ether glycol (PTMG), polyethylene glycol (PEG), polypropylene glycol (PPG), or other aliphatic polyether diols, or other polyols (long chain diols) Include. Hard segments include diisocyanate and short chain diols.

The soft segment includes polyester polyols such as polyethylene adipate, polybutylene adipate, other adipic acid esters (ADP), polycaprolactone (PCL), polycarbonates (PC), and other aliphatic polyester diols The lower surface is a thermoplastic polyurethane elastomer having excellent mechanical strength, heat resistance, abrasion resistance, and chemical stability. On the other hand, if the soft segment is polytetramethylene ether glycol (PTMG) or other polyether polyols, thermoplastic polyurethane elastomers having excellent water resistance and low temperature properties are obtained. In addition, in the MDI-based thermoplastic polyurethane elastomer using an aliphatic glycol chain extender for the hard segment, when the length of the chain extension is extended, the cohesive density between the chains is lowered and the physical properties are lowered.

The toothed belt constructed in this way has the advantage of excellent wear resistance, durability, and back transportability (due to the high μ value).

In addition, the hardness of the thermoplastic elastomer can be about A70 to A95 (durometer hardness of JIS-K6253). The toothed belt constructed in this way has the advantages of excellent flexibility, durability, and high load performance.

Further, in the present invention, the toothed belt is formed so that the thermoplastic elastomer prevents the surface side of the belt teeth from seeping out from the position where the weave of the canvas is unfolded. The thermoplastic elastomer exposed on the surface side of the belt can be easily peeled off and can be deposited on the bottom of the pulley during operation of the belt, which may result in poor engagement, deterioration in jumping performance, deterioration in durability, and abnormal noise.

Another object of the present invention is to provide a method for producing the toothed belt, which can prevent the resin from leaking from the toothed belt surface to prevent mold defects.

That is, according to the present invention, forming a preform of the thermoplastic elastomer, forming the assembly by forming the canvas, the cord, and the preform in a molding mold, pressurizing the assembly from the outside of the molding mold And heating the assembly from the inside of the molding mold for a predetermined time at a temperature above the crystallization temperature of the thermoplastic elastomer and below the melting point of the thermoplastic elastomer, thereby forming a saw tooth on the surface of the assembly. Provided is a manufacturing method of a toothed belt.

In the manufacturing method of the toothed belt, the assembly is pressurized and heated from the outside of the molding mold, and the fluidity of the thermoplastic elastomer is heated by heating the assembly from the inside of the molding mold for a predetermined time at a temperature above the crystallization temperature of the thermoplastic elastomer and below the melting point of the thermoplastic elastomer. Can be controlled. The temperature condition may be maintained for a predetermined time to form a tooth. That is, it is possible to spend a predetermined amount of time for forming the belt in the state in which the flowability of the thermoplastic elastomer is controlled under the specific molding temperature conditions, thereby preventing the thermoplastic elastomer from leaking from the gap of the canvas to the belt tooth surface and mold defect. In addition, tip rounding, in which the teeth cannot be formed completely, is also prevented.

In general, the molding temperature range, ie, the temperature range above the crystallization temperature of the thermoplastic elastomer and below the melting point, is in the range of 125 ° C to 190 ° C.

In addition, the molding temperature is controlled so that the flow rate of the thermoplastic elastomer is approximately 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec (load 50 kgf / cm 2, the diameter and length of the hole 1 mm × 1 mm) The teeth can be formed by heating for a while.

If the molding temperature conditions are set such that the temperature exceeds the crystallization temperature of the thermoplastic elastomer and below the melting point, and the flow rate of the thermoplastic elastomer is between 5 × 10 ⁻⁴ ml / sec and 6 × 10 ⁻³ ml / sec, The resin is prevented from leaking from the gap to the belt tooth surface, and mold defects of the belt (tip rounding where the teeth cannot be formed completely) are prevented, thereby making the mold more precise.

In order to measure the flow amount of the thermoplastic elastomer, a flow tester CFT-500 manufactured by Shimadzu Mfg. Et al. Can be used. The test conditions were 50 kgf / cm 2 of load, 100 seconds of preheating time, 1 cm 2 of cross section of a cylindrical plunger, and 1 mm × 1 mm of diameter × length of the die. Also, after reaching the set temperature (measurement temperature), after preheating for 100 seconds (keeping the same temperature for 100 seconds and keeping the whole sample at the same temperature), a plunger is used to apply a load of 50 kgf / cm2 to the sample. The flow rate of the sample per unit time flowing out of the hole in the die is measured.

Further, the ratio of the filament denier of the canvas (weft / warp) is 0.5 to 3.0, the ratio of the yarn density (weft / warp) is 0.5 to 1.0, and the elongation rate of the canvas to be subjected to mold treatment It is preferably about 50% to 150% (at 50 mm width / 2 kgf). In addition, the canvas is preferably treated with a resin or moisture-curable urethane before casting.

By constructing the canvas in this way, even if the canvas is pressed against the thermoplastic elastomer flowing during the casting, and the canvas is stretched, the filaments overlap and the opening of the gap is reduced, preventing resin from leaking from the gap of the canvas to the belt tooth surface. In addition, mold defects of the belt (tip rounding in which the teeth cannot be formed completely) are also prevented, thereby making the mold more precise. In addition, by the resin treatment or the moisture hardening type urethane treatment, the bond between the thermoplastic elastomer and the canvas becomes stronger.

Further, according to the present invention, the step of disposing a canvas having elasticity on the tooth forming surface of the mold having a sawtooth shape, laminating a resin film extending together with the canvas on the surface of the canvas adjacent to the molding mold A step of setting the melting point of the resin film higher than the thermoplastic elastomer as the material of the belt body, and molding the thermoplastic elastomer in a molding mold in a state in which it is flowable at a temperature lower than the melting point. A manufacturing method is provided.

In the manufacturing method of the toothed belt, the resin film laminated on the surface of the canvas adjacent to the molding mold extends along the canvas and has a higher melting point than the material of the belt body. If the material of the belt body is flowable at a temperature lower than the melting point temperature of the resin and passes through the gap of the canvas, the resin film having a high melting point and not in the molten state at that time prevents the material of the belt body from passing through. . Therefore, the material of the belt body is not exposed to the surface side of the belt teeth.

Further, the canvas and the resin film may be pressed against the material of the belt body flowing when forming the belt, and expand together until they are molded against the grooves of the molding mold, so that the canvas layer and the resin film layer having substantially the same thickness are formed. do. When the canvas layer forming the bottom surface has a uniform thickness, the pitch line is stabilized and the cord is protected, so that durability is improved.

The material of the belt body may be heated after placing a sheet-like material or other deformable fixed formation material on the molding mold, or converted into a flowable state (liquid resin or molten resin) and fed from the extruder to the molding mold. May be Further, the material of the flowable belt body can be passed through the gap of the canvas to fuse with the resin film.

During the formation of the belt, the resin film becomes somewhat flexible. The material of the belt body, the canvas, and the resin film can be strongly laminated with each other after cooling by passing the material of the belt body through the gap of the canvas to directly fuse with the resin film. Moreover, a polyether ester can also be used as a material of a belt main body, and a polyether ester resin film can also be used as a resin film.

As the material of the belt body, thermoplastic elastomers are preferable, and various types of thermoplastic elastomers can be used. On the other hand, various types of resins or elastomers can be used as the resin film. Of these materials, it is preferable to use polyether ester resin as both components because the polyether ester resin has the excellent high temperature properties, high strength, and rubbery elasticity from low temperature to high temperature of the thermoplastic elastomer. Therefore, its durability is good because of its wide temperature range, excellent vibration absorption, oil and water resistance, and chemical stability, low engagement noise with the pulley, and low coefficient of friction. In addition, the injection molding machine may be used to mold the resin or elastomer as the material of the belt body into the belt, or the belt may be molded by the liquid injection molding of the thermoplastic elastomer using the extruder.

Moreover, in the said method, the phenol resin layer modified by the component containing the phenol which has a side chain containing a phenol carboxylic acid and / or an unsaturated bond is formed in the outermost layer of a canvas. If comprised in this way, the binding property between the material of the belt main body containing polyether ester resin and a canvas will be excellent. Here, treatment of latex (treatment bt latex) or RFL prior to forming the phenolic resin layer on the canvas is effective in reducing friction between the yarns of the canvas and improving the wear resistance of the canvas.

Also in the above method, the cord is embedded and the outermost layer of the canvas is formed of a phenol resin layer modified by a component containing phenol having side chains containing phenolic carboxylic acid and / or unsaturated bonds. If comprised in this way, the binding property between the cord and the material of the belt body containing the polyether ester will be excellent. In order to increase the bond strength between the cord (glass fiber or aromatic polyamide fiber) and the belt body, if necessary, the cord is, for example, with a resorcinol-formaldehyde latex (RFL) layer, or an RFL layer. It may also be formed from a resorcinol-formaldehyde latex (RFL) layer further formed of a coating layer having good binding properties.

1 is a cross-sectional view of a toothed belt according to a first embodiment of the present invention;

2 is a perspective view illustrating a sleeve of the toothed belt of the present invention;

3 is a graph illustrating the relationship between resin fluidity and temperature;

4 is a graph showing the results of a grease resistance test;

5 is a graph showing the results of a drive friction test;

6 is a schematic view showing the structure of a rotational precision tester;

7 is a graph showing a result of a rotation precision test;

8 is a graph showing the results of a response test;

9 is a graph showing the results of a jumping test;

10 is a graph showing the results of an oil resistance test;

11 is a graph showing the results of a static position precision test;

12 is a graph showing the results of a durability test;

13 is a cross-sectional view of the toothed belt according to the second embodiment of the present invention;

14 is a view for explaining a manufacturing method of the toothed belt according to the second embodiment;

15 is a plan view illustrating a state of a gap of a cover fabric; And

It is a figure explaining the conventional manufacturing method of a toothed belt.

* Description of the symbols for the main parts of the drawings *

1: belt

2: toothed

3: bottom

10: belt with

12: canvas

15: Material of the belt body

16: code

17: molding mold

18: gap

20: resin film

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. A first embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]

1 is a cross-sectional view of the toothed belt 10 of the first embodiment of the present invention. The toothed belt 10 has a material 15 of a belt body forming a tooth and a canvas 12 disposed on the surface of the toothed belt 10. In addition, a cord 16 that acts as a tensioning member is embedded in the material 15 of the belt body.

Next, the manufacturing method of the toothed belt made from a thermoplastic elastomer is demonstrated. First, the thermoplastic resin is molded into a sheet-like preform (resin sheet) by an extruder.

As the thermoplastic elastomer, thermoplastic polyether ester elastomers and thermoplastic polyurethane elastomers are used. The thermoplastic polyether ester elastomer has a hard segment represented by the formula [1] and a soft segment represented by the formula [2]. For example, an elastomer having the trade name Pelprene manufactured by Toyobo CO.LTD., Or the trade name Hytrel manufactured by DUPONT-TORAY CO.LTD. Can be used. Can be.

In addition, as a thermoplastic polyurethane elastomer of a preform, Nitrac Miractran brand name Miractran or BASF Japan company brand Elastran brand name Elastran Can be used.

As a material of a cord, polyester, glass fiber, aramid, steel, carbon fiber, PBO fiber, etc. can be used, for example.

As the material of the canvas, for example, nylon, polyester, aramid, cotton, or PBO fiber can be used, and the ratio of filament denier of the canvas (weft / warp) is 0.5 to 3.0, and the yarn density ( Weft / warp) ratio is 0.5 to 1.0, the elongation of the canvas is about 50% to 150% (at 50mm width / 2kgf), and the foam is treated with resin or moisture-curable urethane before casting, The canvas is pressed against the flowing thermoplastic elastomer. Therefore, even when stretched, the filament is overlapped and the gap is prevented from opening, thereby preventing the resin from leaking from the gap of the canvas to the belt tooth surface and preventing mold defects of the belt (tip rounding where the teeth are not formed completely). . Therefore, the molding becomes more precise. In addition, the bond between the thermoplastic elastomer and the canvas becomes stronger.

The elastic canvas, cord, and preform are assembled in a metal mold with teeth and the assembly is covered with a rubber bag. The assembly is then pressurized from the outside of the rubber bag to a pressure of 500 KPa to 3000 KPa at a temperature of 70 ° C. to 200 ° C., above the crystallization temperature (depending on the grade of the resin) of the thermoplastic elastomer and to the melting point (grade of the resin). Heating from the inside of the mold for a predetermined time at a temperature of less than). Molding temperature ranges from temperatures above the crystallization temperature of the thermoplastic elastomer to temperatures below the melting point. This depends on the grade of the resin, but is generally 125 ° C to 190 ° C.

At the time of molding, the molding temperature is set to be in a temperature range above the crystallization temperature of the thermoplastic elastomer and below the melting point, so that the flow rate of the thermoplastic elastomer is approximately 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec (load 50 kgf / Cm 2, the diameter and length of the holes are 1 mm × 1 mm), and the assembly is also heated from the inside of the mold for a predetermined time.

By controlling the temperature, the flow rate of the thermoplastic elastomer is set so as to be in the range of about 5 × 10 ^-4 ml / sec to ⁶ × 10 ^-3 ml / sec, so that the resin leaks on the belt tooth surface where the teeth cannot be formed completely. The belt can be formed precisely with or without tip rounding. In the last step of the hot pressing mold, the assembly is cooled and removed from the mold to obtain a toothed belt sleeve (see FIG. 2).

The sleeve of the toothed belt 1 has a tooth 2 and a bottom 3 engaged with a pulley or the like. Thereafter, the sleeve is cut to a predetermined width to obtain a toothed belt (timing belt).

[Examples of Thermoplastic Elastomers]

Next, the example which shows the setting of the flow amount of a thermoplastic elastomer is demonstrated with reference to FIG. 3 and Table 1. FIG.

3 is a graph showing the relationship between fluidity and temperature of the resin. In the graph, TPEE-A and TPEE-B are thermoplastic polyether ester elastomers (manufactured by Toyobo Co., Ltd., Pelphrine), and TPEE-C and TPEE-D are also thermoplastic polyether ester elastomers (trade name Hytrel manufactured by DuPont-Toray Corporation). )to be. In addition, TRU-A is a thermoplastic polyurethane elastomer (trade name Elastran by BSF Japan), and TRU-B and TRU-C are also thermoplastic polyurethane elastomers (trade name Miraxtran by Nippon Miraxtran).

Table 1 shows the relationship between the form of the resin and the belt formability. (The canvas and the canvas E are described later in Table 2).

Form and Formability of Resin Suzy Molding temperature (℃) Liquidity of Resin (ml / s) leakage Tip rounding Overall rating TPEE-A 125 4.20E-04 none has exist X TPEE-A 130 5.54E-03 none none TPEE-A 135 1.03E-02 has exist none X TPEE-B 140 1.24E-03 none none TPEE-B 145 3.95E-03 none none TPEE-C 150 6.20E-04 none none TPEE-C 155 3.30E-03 none none TPEE-D 165 1.62E-03 none none TPEE-D 170 5.43E-03 none none TPU-A 180 3.53E-03 none none TPU-B 180 2.57E-03 none none TPU-C 185 1.85E-03 none none TPU-C 190 6.14E-03 has exist none X TPU-C 195 9.12E-03 has exist none X

Canvas E

First, in the case of TPEE-A, when the molding temperature is set to 130 ° C, the flow rate is 5.54 × 10 ⁻³ ml / sec (load 50kgf / cm 2, hole diameter and length 1mm × 1mm) or about 5 × 10 ⁻⁴ It became the range of ml / sec- ⁶ * 10 <^-3> ml / sec. It was possible to accurately form a belt without tip rounding, in which resin leaked out or the teeth did not form completely on the belt tooth surface.

Next, in the case of TPEE-B, when the molding temperature is 145 ° C, the flow amount is 1.24 × 10 ^-3 ml / sec, while when the molding temperature is set to 140 ° C, the flow amount is 3.95 × 10 ^-3 ml / sec or The range was about 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of TPEE-C, when the molding temperature is 155 ° C, the flow amount is 6.02 × 10 ^-4 ml / sec, while when the molding temperature is set to 150 ° C, the flow amount is 3.30 × 10 ^-3 ml / sec or The range was about 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of TPEE-D, when the molding temperature is 170 ° C., the flow amount is 1.62 × 10 ⁻³ ml / sec, while when the molding temperature is set to 165 ° C., the flow amount is 5.43 × 10 ⁻³ ml / sec or The range was about 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of TPU-A, when the molding temperature is set to 180 ° C, the flow amount is in the range of 3.53 × 10 ⁻³ ml / sec or about 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec. It became. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of TPU-B, when the molding temperature is set to 180 ° C, the flow rate is in the range of 2.57 × 10 ⁻³ ml / sec or about 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec. It became. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Finally, in the case of TPU-C, when the molding temperature is set to 185 ° C, the flow rate is in the range of 1.85 × 10 ⁻³ ml / sec or about 5 × 10 ⁻⁴ ml / sec to ⁶ × 10 ⁻³ ml / sec. It became. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

[Example of the canvas]

With reference to Table 2, the example which shows another filament denier weft / warp ratio, a yarn density weft / warp ratio, and the draw amount of a canvas is demonstrated. Table 2 shows the relationship between the morphology and formability of the canvas (as the resin, TPEE-B was used, and the molding temperature was set to 145 ° C).

Form and formability of canvas canvas Ratio of denier of filament (weft / warp) Ratio of yarn density (weft / warp) Elongation process leakage Tip rounding Overall rating A 1.00 0.59 28 Suzy has exist has exist X B 3.80 0.63 48 Suzy none has exist X C 2.67 0.63 61 Suzy none none D 3.67 0.63 58 RFL has exist none X E 0.95 0.65 63 Suzy none none F 0.95 0.65 68 urethane none none G 0.95 0.38 51 Suzy none has exist X H 0.95 0.98 131 Suzy none none I 0.95 0.97 162 urethane has exist none X J 0.95 0.98 136 RFL has exist none X K 0.46 0.98 142 Suzy has exist none X L 0.71 1.60 180 Suzy has exist none X

Resin: TPEE-B

Molding Temperature: 145 ℃

As shown in Table 2, in the example of the case of the canvas C, the ratio (weft / warp) of the weft filament denier to the warp filament denier was set to 2.67, and the ratio (weft / warp) of the yarn density (number) was Was set to 0.63. Thus, the canvas was fabricated at a stretch rate of 61% at 50 mm width / 2 kgf and then numerically processed. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of canvas E, the ratio of the filament denier (weft / warp) was set to 0.95, the ratio of the thread density (number) (weft / warp) was set to 0.65, and the elongation of the canvas was (50 mm width). At 2 kgf) and resin treatment was performed. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of the canvas F, the ratio of the filament denier (weft / warp) was set to 0.95, the ratio of the thread density (number) (the weft / warp) was set to 0.65, and the elongation of the canvas was (50 mm width). 68%) and moisture hardening urethane treatment was performed. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

Next, in the case of canvas H, the ratio of the filament denier (weft / warp) was set to 0.95, the ratio of the thread density (number) (weft / warp) was set to 0.98, and the elongation of the canvas was (50 mm width). 131%) and resin treatment was performed. It was possible to accurately form the belt without resin leakage or tip rounding on the belt tooth surface.

[Example of test result]

Next, the measurement test result of the small pitch toothed belt of this invention is demonstrated. The pitch size of the toothed belt was 2 mm.

The toothed belts of Examples 1 and 2 were manufactured using the molding conditions described above. Example 1 was made of a thermoplastic polyether ester elastomer (trade name Hytrel 3046), and Example 2 was made of a thermoplastic polyether ester elastomer (trade name Hytrel 4057 manufactured by DuPont-Toray Corporation). And, the toothed belt of Comparative Example 1 was made of castable polyurethane (thermosetting polyurethane elastomer).

The toothed belt was completely immersed in grease for grease resistance test. As shown by the graph of the results in Table 4, the belts of Examples 1 and 2 are better, characterized by a lower rate of change in numerical values (width and thickness) than in Comparative Example 1.

The toothed belts of Examples 3, 4, and 5 were manufactured using the molding conditions described above. Example 3 was made of a thermoplastic polyether ester elastomer (trade name Hytrel 4057 manufactured by DuPont-Toray Corporation), and Example 4 was made of a thermoplastic polyether ester elastomer (trade name Hytrel G3548L), and Example 5 was made of thermoplastic poly Prepared from ether ester elastomer (trade name Hytrel 3046).

The toothed belt of Comparative Example 2 was made of hard chloroprene rubber, the toothed belt of Comparative Example 3 was made of soft chloroprene rubber, and Comparative Example 4 was made of castable thermosetting polyurethane elastomer.

The drive friction test was performed using the torque difference between the drive side and the driven side as drive friction. As shown by the graph of the results of FIG. 5, the belts of Examples 3, 4, and 5 exhibit the same drive torque despite the greater hardness and thickness of the belt compared to Comparative Examples 2, 3, and 4 It was. It is also better because it has less driving friction while improving the durability of the belt.

The toothed belt of Example 6 was manufactured using the thermoplastic polyether ester elastomer (trade name Hytrel 4057 by DuPont-Toray Corporation) using the molding conditions mentioned above. The toothed belt of Comparative Example 5 was made of chloroprene rubber and subjected to rotational precision test as follows.

As shown in FIG. 6, a rotational precision tester (non-contact speed unevenness meter LV-203 manufactured by Mitsubishi Denki Corporation) was used as a measuring instrument. Belt size is 318-2GT-10, 3A for canvas, 40: 0 to 200D / 1 cord, P14 / P14 for pulley size (same as durability test), 200min ^-1 rotation speed (26666pps 1/160 drive) And the installation tension was 28.05N (standard).

As shown by the graph of the result of FIG. 7, the belt of Example 6 is better because of less variation in the rotation of the drive pulley compared to Comparative Example 5.

The toothed belt of Example 7 was manufactured using the molding conditions mentioned above. A thermoplastic polyether ester elastomer (trade name Hytrel 4057 manufactured by DuPont-Toray Corporation) was used. The toothed belt of Comparative Example 6 was made of a castable thermoset polyurethane elastomer.

In the response test, the rotating pulley was stopped and the displacement of residual vibration of the driving pulley was measured. As shown by the graph of the result of FIG. 8, the belt of Example 7 is better because of less overshoot and faster damping of vibration than the belt of Comparative Example 6.

The toothed belts of Examples 8, 9, and 10 were manufactured using the molding conditions described above. Example 8 was prepared with a thermoplastic polyether ester elastomer (trade name Hytrel 4057 manufactured by DuPont-Toray, Inc.), and Example 9 was prepared with a thermoplastic polyether ester elastomer (trade name Hytrel G3548L), and Example 10 was thermoplastic. Prepared with a polyether ester elastomer (trade name Hytrel 3046).

The toothed belt of Comparative Example 7 was made of hard chloroprene rubber, the toothed belt of Comparative Example 8 was made of soft chloroprene rubber, and the toothed belt of Comparative Example 9 was made of castable thermosetting polyurethane elastomer.

In addition, after the belt was mounted on the measuring instrument and rotated at a constant speed, a jumping test was performed by gradually increasing the torque of the hysteresis brake. As shown by the graph of the results of FIG. 9, the belts of Examples 8, 9, and 10 are better because of the higher jumping torque than Comparative Examples 7, 8, and 9.

Next, a large pitch toothed belt was manufactured to perform the following performance test. The pitch size of the toothed belt was 9.525 mm.

The toothed belt of Example 11 was manufactured with the thermoplastic polyether ester elastomer (trade name Hytrel 4057 by DuPont-Toray Corporation) under the molding conditions mentioned above. In addition, the toothed belt of Comparative Example 10 was made of chloroprene rubber.

After the belt was immersed in machine oil for one week, the oil resistance test was performed by measuring the belt size and hardness. As shown by the graph of the result of FIG. 10, the belt of this Example 11 is better because the amount of change in hardness and belt size is smaller than that of Comparative Example 10.

The toothed belt of Example 12 was manufactured using thermoplastic polyether ester elastomer (trade name Hytrel 4057 manufactured by DuPont-Toray Corporation) under the molding conditions described above. In addition, the toothed belt of Comparative Example 11 was made of chloroprene rubber.

The static position precision test was performed with a measuring instrument as shown in the upper left of FIG. As shown by the graph of the result of FIG. 11, the belt of Example 12 had a small amount of displacement. The displacement amount obtained by converting the rotational angle of the pulley to the load into an offset on the pitch line is smaller than that of Comparative Example 11, which is superior.

The toothed belt of Example 13 was manufactured with the thermoplastic polyether ester elastomer (trade name Hytrel 4057 by DuPont-Toray Corporation) under the molding conditions mentioned above. In addition, the toothed belt of Comparative Example 12 was made of chloroprene rubber.

The belt was wound around the pulley and subjected to a durability test at a given rotational speed and a predetermined load. As shown by the graph of the results in FIG. 12, the belt of Example 13 is better because it has more bending times than Comparative Example 12 under the same conditions.

In this embodiment, the molding temperature is in the range between the crystallization temperature of the thermoplastic elastomer and the melting point, thereby preventing the resin from leaking to the belt tooth surface and generating tip rounding. Therefore, the present embodiment provides a toothed belt having excellent driving resistance, durability, and responsiveness as well as a reduction in driving friction as compared with the conventional embodiment.

Second Embodiment

Hereinafter, a second embodiment of a toothed belt and a manufacturing method thereof will be described with reference to the drawings.

13 is a sectional view of the toothed belt 10 according to the second embodiment. The difference from the first embodiment is that the resin film 20 is provided on the surface of the canvas 12. The resin film 20 functions as a sealant for the mold and functions as a barrier for the toothed belt after manufacture.

Next, the manufacturing method of the toothed belt of 2nd Example is demonstrated. As shown in a, b, and c of Fig. 14, in the manufacturing method of the toothed belt, the elastic canvas 12 is disposed on the tooth forming surface of the forming mold 17 having a sawtooth shape. The resin film 20 is first laminated on the surface of the canvas 12. Next, the cord 16 is arrange | positioned at the canvas 12 near the tooth formation surface of the shaping | molding mold 17. Next, as shown in FIG. In the figure, reference numeral 19 denotes a rubber bag for molding. During molding, the resin film 20 adjacent to the molding mold 17 is stretched together with the canvas 12.

The resin film 20 is set to a higher melting point than the material 15 of the belt body. A polyether ester resin is used as the material 15 of the belt body, and a polyether ester resin film is used as the resin film 20.

In addition, when the material 15 of the belt main body becomes flowable at a temperature lower than the melting point of the resin film 20, it can be molded in the molding mold 17. If the gap 18 (see a in FIG. 15) of the canvas 12 for forming is stretched and inflated due to the pressure of the material 15 of the belt body (see b in FIG. 15), the cord 16 from the back of the belt The material 15 of the belt body passing between them leaks from the gap 18 of the canvas 12 and fuses with the resin film 20.

In the manufacturing method of the toothed belt, the resin film 20 is set to a melting point higher than the material 15 of the belt body and laminated on the toothed surface of the canvas 12 (see a in FIG. 14). Even if the material 15 of the belt body passes through the gap 18 (see b in FIG. 15) of the canvas 12 from the back during molding, the resin film 20 fuses with the material 15 of the belt body to form a tooth. Reaching the plane can be prevented (see c of FIG. 14). That is, during molding, the resin film 20 higher than the melting point and not in the molten state prevents the material 15 of the belt body from passing through.

Therefore, the leakage of the material 15 of the belt main body to the belt tooth surface (see FIG. 16 which shows that the material of the belt body leaks) is prevented, and there is an advantage that the material is not exposed to the surface side of the belt tooth. Due to this, since there is no unbalanced state between the portion where the material 15 of the belt body is exposed and the portion that is not, the occurrence of abnormal noise can be suppressed compared to the conventional belt, and the jumping performance and durability can be improved. have.

Moreover, since the surface of the canvas 12 is laminated | stacked with the layer of the resin film 20 on the toothed surface of the manufactured toothed belt, it is for oil or water to penetrate the resin film 920 side from the belt tooth side. Can be prevented. Therefore, the dimensional stability of the belt is excellent and the service life is long.

Various types of resins or elastomers may be used as the material of the belt body, but when polyether ester resin is used, the high temperature characteristics of the thermoplastic elastomer are excellent, and high strength and elasticity such as rubber are exhibited from low to high temperatures. The temperature range is wide, the vibration absorption is improved, the oil resistance and water resistance are improved, the chemical stability is excellent, the noise is reduced when engaged with the pulley, and the durability is increased due to the low coefficient of friction.

In addition, as the material 15 of the belt body, the belt may be molded with an injection molding machine using a liquid castable resin or elastomer, or the belt may be molded with an extruder using a thermoplastic elastomer.

[First Embodiment of Method for Manufacturing Attached Belt]

Next, the manufacturing method of the toothed belt of this invention is demonstrated.

The nylon canvas (toothed cloth) 12 is laminated to a resin film (hydrel film) 20 having a melting point higher than that of the material of the belt body (hytrel sheet) 15 and cut to a predetermined dimension. And combine (referred to as "cover fabric jacket").

After the canvas 12 is treated with latex and RFL, the outermost layer is formed of a phenol resin layer having a side chain having an unsaturated bond. Instead of the phenol resin layer, a phenol resin layer modified with a component containing phenol carboxylic acid may be formed.

The canvas jacket is covered on the toothed surface at the outer surface of the molding mold 17 so that the resin film (Hytriel film) 20 contacts the mold surface of the molding mold 17, and then the glass cord 16 is placed on the outer surface. Spirally wound around.

The outermost layer of cord 16 is formed of a phenol resin layer having a side chain having an unsaturated bond. Also, in order to increase the bond strength between the cord 16 and the belt body, an RFL layer is formed on the cord 16, and then a coating layer having excellent bondability with the RFL layer is formed.

The material (hydrel sheet) 15 of the belt body at room temperature is wound around the cord 16 and fixed with an adhesive tape. The release paper is wound on the belt body material (hytrel sheet) 15 and fixed with adhesive tape, then the assembly is inserted into a shell bag and placed in a vulcanization pot. Pressurized heating to form a belt slab (belt slab). The heating temperature is set to a temperature that is equal to or higher than the melting point of the material (hytriel sheet) 15 of the belt body and less than the melting point of the resin film (hytriel film) 20. Pressing and heating times are set such that the material 15 of the belt body flows to form a complete belt tooth.

That is, the material of the belt body (hydrel sheet) 15 is first placed on the molding mold 17 together with the canvas 12 laminated with the resin film 20 and the cord 16 in an unheated resin sheet state. do. Then, during molding, the material 15 of the belt body is pressurized and heated from room temperature until the melting temperature is reached. Therefore, the material 15 of the belt body is plasticized to become flowable and form belt teeth.

By doing so, the resin film (hytriel film) 20 laminated on the canvas 12 is stretched together with the elongation of the canvas 12 during molding, and the canvas 12 covered with the resin film 20 when the belt teeth are formed. Is formed on the belt tooth surface.

After the end of molding, the molding mold 17 is immediately cooled by water to bring it to room temperature. The molding mold 17 is taken out of the shell back and the molded slab is removed from the molding mold with a de-molding device. The molded slab is polished with a slab grinder to remove the release paper, adjusted to a predetermined belt thickness, and then printed and cut to obtain a toothed belt.

Therefore, the obtained toothed belt has the resin film 20 layer, the canvas 12 layer impregnated with the material 15 of the belt body, and the material 15 of the belt body in order from the surface of the belt tooth. 16). That is, the resin film 20 prevents the material 15 of the belt body from leaking to the belt tooth surface, and the canvas 12 covered with the resin film 20 is formed on the belt tooth surface.

Second Embodiment of Attached Belt Manufacturing Method

Hereinafter, another Example of the manufacturing method of a toothed belt is described.

In order to make the belt tooth side the hytrel film (referred to as "preformed canvas") 20, the nylon canvas (sticky cloth) 12 has a melting point higher than the material of the belt body (hydrel sheet) 15. The branches are laminated with a resin film (hydrel film) 20 and performed with a preforming machine (not shown).

The preformed canvas is cut and joined to match the number of teeth and the tooth width of the molding mold 17. It is arrange | positioned at the tooth formation surface of the outer periphery of the shaping | molding mold 17, and is temporarily fixed so that it may not slip on a seam. The glass cords 16 are then spirally wound around the molding mold 17.

The material (hydrel sheet) 15 of the belt body at room temperature is wound on the cord 16 and fixed with an adhesive tape. The release paper is wound on the material of the belt body (hydrel sheet) 15 and fixed with adhesive tape, then the assembly is inserted into the shell bag and heated under pressure to form a belt slab.

The heating temperature is set to a temperature that is equal to or higher than the melting point of the material (hytriel sheet) 15 of the belt body and less than the melting point of the resin film (hytriel film) 20. Pressurization and heating times are set such that resin flows to form belt teeth completely.

After the end of molding, the molding mold 17 is immediately cooled by water to bring it to room temperature. The molding mold 17 is taken out of the shell bag and the molded slab is removed from the molding mold with a demolder. The molded slab is polished with a slab grinder to remove the release paper, adjusted to a predetermined belt thickness, and then printed and cut to obtain a toothed belt.

According to this method, since the canvas 12 and the resin film (hydrel film) 20 are not extended much, the fluctuation | variation of the yarn density of the canvas 12, the thickness of the resin film 20, etc. can be reduced. In addition, productivity and durability are good.

In this embodiment, a resin film 20 having a melting point higher than that of the material 15 of the belt body is laminated on the canvas 12. The melting temperature is set between the melting point of the resin film 20 and the melting point of the material 15 of the belt body. Therefore, even if the material 15 of the belt body has fluidity, leakage of the material 15 of the belt body can be prevented by the hard resin film 20. There is no imbalance between the exposed and unexposed portions of the belt body. The occurrence of abnormal noise can be suppressed as compared with the conventional belt, and the jumping performance and durability can be improved.

Finally, various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the present invention.

According to the toothed belt according to the present invention, it has excellent jumping resistance, improved durability, reduced driving friction, and improved responsiveness as compared to conventional products (rubber belt or thermosetting polyurethane elastomer belt), and can prevent abnormal noise. Can be.

Moreover, according to the manufacturing method of the toothed belt which concerns on this invention, it can prevent that resin leaks from the toothed belt surface, and can prevent mold defect.

Claims (12)

In the toothed belt having a toothed surface, A belt body made of thermoplastic elastomer; A cord embedded in the belt body to act as a tension member; And Toothed belt comprising a canvas covering the tooth surface. 2. The toothed belt according to claim 1, wherein the thermoplastic elastomer is a thermoplastic polyether ester elastomer. 2. The toothed belt according to claim 1, wherein the thermoplastic elastomer is a thermoplastic polyurethane elastomer. 2. The toothed belt according to claim 1, wherein the thermoplastic elastomer has a hardness in the range of A70 to A95 (durometer hardness of JIS-K6253). In the manufacturing method of the toothed belt, Forming a preform of a thermoplastic elastomer; Assembling the canvas, cord, and the preform into a mold to form an assembly; Pressurizing the assembly from the outside of the molding mold; And Heating the assembly from the inside of the molding mold for a predetermined time at a molding temperature above the crystallization temperature of the thermoplastic elastomer and below the melting point of the thermoplastic elastomer, thereby forming a saw tooth on the surface of the assembly. Method for manufacturing toothed belt. 6. The toothed tooth according to claim 5, wherein the teeth have a flow rate of 5 x 10 ^-4 ml / sec to ⁶ x 10 ^-3 ml / sec (load 50 kgf / cm 2, hole diameter and length of 1 mm x 1 mm). The method of manufacturing a toothed belt, characterized in that formed by setting the molding temperature so as to be in a range and heating for a predetermined time. 6. The method of claim 5, wherein the ratio of the weft / warp filament denier of the canvas is 0.5-3.0, the ratio of the yarn density of the weft / warp is 0.5-1.0, and the canvas is treated with a resin or moisture-curable urethane before forming the granulated body. And the canvas has an elongation of 50% to 150% of its original length (at 50mm width / 2kgf). Attaching a resin film on the surface of the canvas in contact with the molding mold having the toothed surface, the resin film having a melting point higher than that of the material of the belt body, being laid together with the canvas; Arranging the canvas having elasticity on the toothed surface; Winding a cord onto the canvas; And And molding the material of the belt body using the molding mold in a state in which the material of the belt body is flowable at a temperature lower than the melting point. The method of claim 8, wherein in the forming step, the material of the flowable belt body is fused with the resin film through the weave of the canvas. The phenol resin layer according to claim 8, wherein a phenol resin layer modified by a component containing phenol having a side chain having phenolic carboxylic acid and / or unsaturated bonds is formed on the outermost layer of the canvas before the attaching step. Manufacturing method of the belt attached. The phenol resin layer according to claim 8, wherein a phenol resin layer modified by a component containing phenol having a side chain having a phenolic carboxylic acid and / or an unsaturated bond is formed on the outermost layer of the cord before the winding step. Manufacturing method of the belt attached. The method of manufacturing a toothed belt according to claim 8, wherein the material of the belt body comprises a polyether ester and the resin film comprises a polyether ester.