JP2005214230A - High load transmission belt and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress noise of frequency resulted from a block pitch in noise generated by contact of a pulley with a block. <P>SOLUTION: A high load transmission belt 1 is formed by fixing a plurality of blocks 20 along a longitudinal direction of a tension band 10 so that the predetermined numbers of blocks 20 constitute a group of blocks. In the group of the blocks, each of the blocks 20 is arranged so that all of block pitches as intervals between neighboring blocks 20 are equal. Each group end block pitch as an interval between end blocks 20 each of neighboring groups in a neighboring direction is larger than the block pitch, and has a value smaller than twice the value of the block pitch. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high-load transmission belt in which a plurality of blocks are fixed along the longitudinal direction of a tension band and a method for manufacturing the same.

A high load transmission belt used in a belt type continuously variable transmission provided in a vehicle such as an automobile is
By changing the width of the V groove formed between the fixed pulley fixed on the shaft and the movable pulley movable along the shaft with respect to the fixed pulley, the effective diameter wound is changed to adjust the transmission ratio. Since the side pressure from the pulley increases, the belt must be able to withstand the large side pressure. In addition to continuously variable speed applications, it is necessary to use a belt that can withstand a particularly high load for high load transmission applications where the life of conventional rubber belts is too short.

  Among those used as such a high load transmission belt, for example, as disclosed in Patent Document 1, a tension band in which a core wire is embedded in an elastomer such as rubber, and an equal pitch with respect to this tension band Some of them have a plurality of blocks fixed by the Specifically, the upper and lower surfaces of the tension band are provided with concave grooves formed along the width direction at equal pitches in the longitudinal direction. On the other hand, an opening for fitting a tension band is formed at the center of the block, and convex portions are provided on the upper surface and the lower surface of the opening, respectively. The block is fixed at an equal pitch along the longitudinal direction of the tension band by fitting the convex part into the groove of the tension band. Note that both side surfaces of this block are inclined surfaces that engage with the V-grooves of the pulley.

The above-described high load transmission belt is manufactured by injection molding a block using a pair of molds at a predetermined position of a tension band. Specifically, this mold has a tension band holding part and a tension band in which a plurality of blocks formed at an equal pitch are held by the tension band holding part in a state where a pair of molds are combined. A plurality of block forming cavities arranged so as to be fitted to each other are formed. By using such a mold, the block can be attached to the tension band at the same time as the block is molded. Therefore, the time required for manufacturing the belt can be greatly reduced as compared with the case where the belt is manufactured by creating the block separately from the tension band and fitting the blocks one by one in the tension band.
JP 2003-202054 A

  When the both side surfaces of each block of the high load electric belt are operated in contact with the surface of the V groove of the pulley, noise is generated due to the contact between the block and the pulley. In particular, since the pitch of each block is equal, there is a problem that noise at a frequency due to the block pitch becomes significant. Therefore, it is conceivable to reduce the noise by making the block pitch random and dispersing the noise frequency. However, since the manufacturing process of a belt having a random block pitch is complicated, there arises a problem that the manufacturing cost of the belt increases.

  Accordingly, an object of the present invention is to provide a high-load transmission belt that can be manufactured by a simple method while suppressing noise at a frequency caused by a block pitch.

Means and effects for solving the problems

  The high load transmission belt according to the present invention comprises a predetermined number of the blocks arranged at a predetermined pitch in a high load transmission belt having a tension band and a plurality of blocks provided along the longitudinal direction of the tension band. A plurality of groups are formed, and a pitch between the blocks arranged at adjacent end portions of the adjacent groups has a value different from a multiple of the predetermined pitch.

  According to this configuration, the pitch between groups has a value different from a multiple of the predetermined pitch. Therefore, the frequency of noise generated by contact between a plurality of blocks included in one group and the pulley is different from the frequency of noise generated by contact between the plurality of blocks included in another group and the pulley. Become. Therefore, the noise frequency is preferably dispersed. As a result, frequency noise caused by the block pitch frequency can be suppressed.

  In the high load transmission belt of the present invention, it is preferable that the pitch between the blocks arranged at the end portions in the adjacent direction of the group is smaller than twice the predetermined pitch. According to this configuration, it is possible to suppress a decrease in belt strength due to an excessively wide pitch between blocks arranged at the adjacent end portions of the group.

  In the method for manufacturing a high load transmission belt according to the present invention, in the method for manufacturing a high load transmission belt having a tension band and a plurality of blocks provided along the longitudinal direction of the tension band, Using a mold having a plurality of cavities for block molding arranged so that a predetermined number of blocks molded at a pitch are fitted to the tension band held by the tension band holding part By injecting resin into the cavity in the mold with the tension band set in the tension band holding portion, a group consisting of a predetermined number of the blocks is formed, and at the same time, the group of the group with respect to the tension band. A step of attaching each of the blocks, and by repeating the step a plurality of times, the blocks disposed at the adjacent end portions of the adjacent groups. Tsu pitch between click to form a plurality of groups so as to have a value different from a multiple of the predetermined pitch.

  According to this, the molding of the block and the attaching operation to the tension band of the block can be performed simultaneously. Accordingly, the work of fitting the blocks one by one in the tension band is not necessary, and the time required for manufacturing the belt can be greatly reduced. Further, according to this method, since the blocks are formed for each group, it is easy to change the pitch between the blocks arranged at the adjacent end portions of the adjacent groups without preparing a new mold. be able to.

  In the manufacturing method of the high load transmission belt of the present invention, it is preferable that the dividing surface of the mold is provided so as to pass through the center position in the width direction of the high load transmission belt. Thereby, when the block travels as a belt, the side surface that comes into contact with the pulley becomes a smooth surface without a parting line. Therefore, problems such as noise and initial friction at the initial stage of belt running can be suppressed.

  In the method for manufacturing a high-load transmission belt according to the present invention, it is preferable that the dividing surface of the mold is provided along the end in the width direction of the tension band. According to this, when the tension band is set to one of the pair of molds, the tension band does not protrude from the split surface, so the tension band may be bent when the pair of molds are combined. It is possible to suppress the tension band from being damaged by being caught on the mold.

  In the high load transmission belt manufacturing method according to the present invention, it is preferable that the tension band holding portion of the mold is configured to be able to change an interval in the thickness direction of the tension band. According to this, the distance in the thickness direction of the tension band of the tension band holding part can be widened when the tension band is set in the tension band holding part, and then narrowed. Therefore, the injected resin in the cavity can be prevented from leaking from the gap between the cavity and the tension band.

  In the high load transmission belt manufacturing method of the present invention, it is preferable that the pitch between the blocks arranged at adjacent end portions of the group is larger than the predetermined pitch. According to this, the dimension along the longitudinal direction of the belt of the tension band holding portion can be increased as compared with the case where the pitch between the blocks arranged at the end portions in the adjacent direction of the group is smaller than the predetermined pitch. Therefore, the strength of the mold can be increased.

  In the high load transmission belt manufacturing method of the present invention, it is preferable that the pitch between the blocks arranged at the adjacent end portions of the group is smaller than twice the predetermined pitch. According to this, it is possible to suppress a decrease in belt strength due to an excessively wide pitch between blocks arranged at adjacent end portions of the group.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a high load transmission belt according to a first embodiment of the present invention. 2 is a cross-sectional view of the high load transmission belt of FIG. 1 taken along the line II-II. As shown in FIGS. 1 and 2, the high load transmission belt 1 includes a tension band 10 and a plurality of blocks 20 fixed along the longitudinal direction of the tension band 10. 1 and 2, arrows x, y, and z that are orthogonal to each other indicate the longitudinal direction, the width direction, and the vertical direction of the high-load transmission belt 1 according to the first embodiment of the present invention.

  The tension band 10 has a plurality of core wires 12 embedded in the elastomer 11 along the longitudinal direction. Then, on the upper surface of the tension band 10, block fixing grooves 13a and mold fitting grooves 14a formed in the width direction are alternately provided in the longitudinal direction. On the other hand, on the lower surface, a block fixing groove 13b is provided at a position facing the block fixing groove 13a, and a mold fitting groove 14b is provided at a position facing the mold fitting groove 14a. Here, the block fixing grooves 13a and 13b are respectively fitted to convex portions 20a and 20b described later of the block 20. The mold fitting grooves 14a and 14b are fitted into a tension band holding portion 32 of the mold 30 described later.

  Both side surfaces 23 of the block 20 are inclined surfaces that engage with V grooves 43a and 53a of a drive pulley 43 and a driven pulley 53, which will be described later. An opening 24 into which the tension band 10 is fitted is formed at the center of the block 20. And the convex part 20a, 20b which each fits into the block fixing groove 13a, 13b of the above-mentioned tension belt | band | zone 10 is formed in the upper surface and lower surface in the opening part 24 (refer FIG. 2). Therefore, the plurality of blocks 20 are fixed to the tension band 10 by fitting the block fixing grooves 13a and 13b and the convex portions 20a and 20b.

Here, the pitch of each block 20 (interval between adjacent blocks 20) will be described with reference to FIG. In the high load transmission belt 1, a plurality of groups are formed by a predetermined number of blocks 20. In FIG. 2, one group is formed by a plurality of blocks 20 included in a portion surrounded by a dotted line. In each group, the blocks 20 are fixed to the tension band 10 so that the intervals between the adjacent blocks 20 (hereinafter referred to as “block pitch”) are equal. In FIG. 2, the block pitch is a. Further, in FIG. 2, an interval between the blocks 20 in the adjacent direction end portions of adjacent groups (hereinafter referred to as “group end block pitch”) is b. The relationship between a and b is expressed by the following (Formula 1).
a <b <2a (Formula 1)

That is, the group end block pitch has a value different from an integer multiple of the block pitch. In FIG. 2, the interval between the groups (hereinafter referred to as “group pitch”) is c. That is, when the number of blocks 20 constituting the group is N, c is expressed by the following (formula 2).
c = a × (N−1) + b (Formula 2)

Here, from (Expression 1) and (Expression 2), the following (Expression 3) is established.
a × N <c <a × (N + 1) (Formula 3)

  That is, from (Equation 3), when the group end block pitch has a value different from an integer multiple of the block pitch, the group pitch also has a value different from the integer multiple of the block pitch.

  The block fixing grooves 13a and 13b formed on the upper surface and the lower surface of the tension band 10 are provided so as to correspond to the pitch of the block 20 described above. The mold fitting groove 14a is formed in the middle between adjacent block fixing grooves 13a. Similarly, the mold fitting groove 14b is formed in the middle between the adjacent block fixing grooves 13b.

  Next, a usage state of the high load transmission belt 1 in the continuously variable transmission will be described with reference to FIGS. 3 and 4. FIG. 3 is a top view showing a state in which the high load transmission belt is wound around the pulley. 4 is a cross-sectional view of the drive pulley of FIG. 3 taken along the line IV-IV. As shown in FIGS. 3 and 4, the high load transmission belt 1 is used by being wound around a drive pulley 43 provided on a drive shaft 40 of a continuously variable transmission and a driven pulley 53 provided on a driven shaft 50. Is. Since the drive pulley 43 and the driven pulley 53 have substantially the same configuration, only the drive pulley 43 will be described here.

  The drive pulley 43 includes a fixed pulley 41 fixed to the drive shaft 40 and a movable pulley 42 that can move along the drive shaft 40 with respect to the fixed pulley 41. Here, the opposing surfaces of the fixed pulley 41 and the movable pulley 42 are referred to as sliding contact surfaces 41a and 42a, respectively. The sliding contact surfaces 41a and 42a are both bulged at the center and inclined toward the peripheral portion. That is, the thicknesses of the fixed pulley 41 and the movable pulley 42 are both thinner at the center portion and closer to the peripheral portion. Thereby, a V-groove 43 a is formed between the fixed pulley 41 and the movable pulley 42. In the continuously variable transmission, the width of the V groove 43a is changed by moving the movable pulley 42, and the gear ratio is adjusted by changing the effective diameter of the drive pulley 43 around which the high load transmission belt 1 is wound. Yes.

  With the above-described configuration, both side surfaces 23 of the block 20 of the high load transmission belt 1 wound around the drive pulley 43 and the driven pulley 53 are slidable contact surfaces 41a and 51a of the fixed pulleys 41 and 51, and the movable pulley 42, 52 abuts against the sliding contact surfaces 42a and 52a. The block 20 receives the driving force from the driving pulley 43 and pulls the tension band 10 that is locked and fixed, thereby transmitting the driving force on the driving shaft 40 side to the driven shaft 50 side.

  Next, a method for manufacturing the high load transmission belt 1 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a schematic perspective view of a mold used in the manufacturing method according to the first embodiment of the present invention. FIG. 6 is a front view of a dividing surface of the mold of FIG. 7 is a VII-VII cross-sectional view of the mold of FIG.

  The above-described high-load transmission belt 1 is manufactured by repeating a plurality of operations in which a group of N blocks 20 are injection molded at the same time and attached to the tension band 10 at the same time using a pair of molds 30 and 31. Is done. The molds 30 and 31 shown in FIGS. 5 and 6 are for molding the five blocks 20 at a time. In the following description, the high number of blocks 20 included in one group is five. A method for manufacturing the load transmission belt 1 will be described.

  The molds 30 and 31 have tension band holding portions 32 that are fitted into the mold fitting grooves 14 a and 14 b of the tension band 10. Specifically, the tension band holding portion 32 includes six mold fitting grooves 14a adjacent to the block fixing grooves 13a and 13b of the tension band 10 into which the convex portions 20a and 20b of the five blocks 20 to be molded are fitted, respectively. 14b.

  Further, five cavities 33 for molding the block 20 are formed in a state where the pair of molds 30 and 31 are combined. The cavity 33 is arranged so as to surround the tension band 10 with the tension band 10 set in the tension band holding part 32. When the block 20 is formed by the cavity 33, the block 20 is formed in a state in which the convex portions 20a and 20b of the block 20 are fitted in the block fixing grooves 13a and 13b of the tension band 10. Further, each cavity 33 is provided with a gate 35 connected to the outside of the mold. The block 20 is formed by injecting the dissolved resin from the gate 35 into the cavity 33.

  It is not necessary to fix the tension band 10 in places other than the cavity 33 for molding the block 20, and as a relief area for the tension band 10 and the block 20 when the molds 30 and 31 are closed, the approximate shape of the block 20 is used. A slightly wider passage 34 is formed.

  Further, in the present embodiment, as shown in FIG. 7, the split surfaces 36 of the molds 30 and 31 pass through the center position in the width direction of the high load transmission belt 1. Accordingly, no parting line is formed on both side surfaces 23 of the block 20 formed using the molds 30 and 31.

  The blocks 20 are formed one group at a time using the molds 30 and 31 as described above. Specifically, after forming the five blocks 20 for one group by one injection molding operation, the tension band 10 and the blocks 20 are removed from the molds 30 and 31. Then, the tension band 10 is rotated in the direction of the arrow A (see FIG. 6) by the group pitch so that the block 20 can be formed at the next position, and the tension band 10 is set again on the molds 30 and 31, 5 blocks for one group are formed at the position of. By repeating such operations, the block 20 is formed over the entire circumference of the tension band 10 to complete the high load transmission belt 1.

  As described above, in the high load transmission belt 1 of the present embodiment, the block pitch is constant and the group end block pitch is a multiple of the block pitch in one group composed of the plurality of blocks 20. The block 20 is fixed to the tension band 10 so as to have a value other than. That is, the group pitch has a value other than a multiple of the block pitch. Therefore, the frequency of noise generated by the contact between the plurality of blocks 20 included in one group and the drive pulley 43 or the driven pulley 53 is different between the block 20 included in the other group and the drive pulley 43 or the driven pulley 53. This is different from the frequency of noise generated by the contact. Therefore, the noise frequency is preferably dispersed. As a result, frequency noise caused by the block pitch frequency can be suppressed.

  The group end block pitch is a value smaller than twice the block pitch. Therefore, it is possible to suppress a decrease in belt strength due to the group end block pitch being too wide. Further, the group end block pitch is larger than the block pitch. Therefore, the dimension along the belt longitudinal direction of the tension band holding portion 32 of the molds 30 and 31 can be increased as compared with the case where the group end block pitch is smaller than the block pitch. Therefore, the strength of the molds 30 and 31 can be increased.

  Moreover, in the manufacturing method of the high load power transmission belt of the present embodiment, the work of using the molds 30 and 31 to injection-mold the block 20 for one group at a time and attach it to the tension band 10 is repeated a plurality of times. Thus, the high load transmission belt 1 is manufactured. Therefore, the operation of fitting the blocks 20 into the tension band 10 one by one is not necessary, and the time required for manufacturing the belt can be greatly shortened. Moreover, according to this method, since the block 20 is shape | molded for every group, the change of a group end block pitch can be easily performed, without preparing the metal mold | dies 30 and 31 newly.

  The dividing surfaces 36 of the molds 30 and 31 pass through the center position in the width direction of the high load transmission belt 1. Therefore, the side surfaces 23 of the block 20 are smooth without forming parting lines. As a result, problems such as noise and initial friction at the initial stage of belt running can be suppressed.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view in the width direction of a mold used in the manufacturing method according to the second embodiment of the present invention.

  The main difference between the manufacturing method of the second embodiment of the present invention and the manufacturing method of the first embodiment is that the divided surfaces of the molds 30, 31 used in the manufacturing method of the first embodiment. 36 passes through the center position in the width direction of the high load transmission belt 1, but the dividing surfaces 136 of the molds 130 and 131 used in the manufacturing method of the second embodiment are Along the end in the width direction. The configuration of the high load transmission belt manufactured by the other manufacturing method and the manufacturing method of the second embodiment is substantially the same as that of the first embodiment, and thus detailed description thereof is omitted.

  As shown in FIG. 8, in the second embodiment of the present invention, injection molding of the block 120 is performed using the molds 130 and 131. The width of the mold 131 is wider than the width of the mold 130, and when the tension band 110 is set in a tension band holding portion (not shown) provided in the mold 131, the end in the width direction of the tension band 110 is divided. It coincides with the surface 36. That is, the tension band 110 does not protrude from the dividing surface 136.

  As described above, in the method for manufacturing a high-load transmission belt according to the present embodiment, the split surfaces 136 of the molds 130 and 131 are along the widthwise ends of the tension band 110, and With the tension band 110 set, the tension band 110 does not protrude from the dividing surface 136. Therefore, when the molds 130 and 131 are put together, the tension band 110 protruding from the dividing surface 136 is not bent or caught by the mold 130 and damaged.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a front view of a dividing surface of a mold used in the manufacturing method according to the third embodiment of the present invention.

  The manufacturing method of the third embodiment of the present invention is mainly different from the manufacturing method of the first embodiment in that the tension bands of the molds 30 and 31 used in the manufacturing method of the first embodiment. Although the interval in the thickness direction of the tension band 10 of the holding part 32 is constant, in the molds 230 and 231 used in the manufacturing method of the second embodiment, the thickness direction of the tension band 210 of the tension band holding part 232 is used. The interval of is variable. The configuration of the high load transmission belt 201 manufactured by the other manufacturing method and the manufacturing method of the third embodiment is substantially the same as that of the first embodiment, and thus detailed description thereof is omitted.

  As shown in FIG. 9, the part forming the cavity 233 in the mold 230 used in the third embodiment of the present invention includes a movable part 230 a that can move in the thickness direction of the tension band 210. It has become. Then, when setting the tension band 210 to the tension band holding part 232, the interval in the thickness direction of the tension band 210 of the tension band holding part 232 is wider than the thickness of the tension band 210, and the tension band holding part 232 has a tension band. After fitting 210 and closing the mold, the movable band 230a is moved in the direction of arrow B by a mechanism including hydraulic pressure, electric power, air pressure, etc. (not shown) to press the tension band holding section 232 and the tension band 210.

  As described above, in the mold 230 used in the method for manufacturing a high load transmission belt according to the present embodiment, the distance in the thickness direction of the tension band 210 of the tension band holding part 232 is variable. Therefore, the distance in the thickness direction of the tension band 210 of the tension band holding part 232 can be widened when the tension band 210 is set in the tension band holding part 232 and can be narrowed thereafter. Therefore, the injected resin in the cavity 233 can be prevented from leaking from the gap between the cavity 233 and the tension band 210.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. Is.

  For example, in the first embodiment described above, the high load transmission belt 1 shown in FIG. 1 is described, but the configuration of the high load transmission belt is not limited to this, and the high load transmission belt 1 shown in FIG. Even with the load transmission belt 301, the same effect as in the present embodiment can be obtained. The high load transmission belt 301 has substantially the same shape as the high load transmission belt 1, but a through hole 313c is formed at the center in the width direction of the block fixing grooves 313a and 313b of the tension band 310. Then, when the block 320 is formed, the resin is also injected into the through hole 313c. Accordingly, two openings 324 and 325 are formed in the block 320. In such a high-load transmission belt 301, the fixing force between the tension band 310 and the block 320 becomes stronger. As a result, in the high-load transmission belt 301, rattling between the tension band 310 and the block 320 that occurs when traveling for a long period of time can be suppressed, and the life can be prolonged.

  In addition, the high load transmission belt 301 in FIG. 10A has one through-hole 313c provided in the tension band 310 per block 320, but is not limited thereto, and a plurality of through-holes 313c are provided. It may be done.

  Furthermore, a high load transmission belt 401 as shown in FIG. In the high load transmission belt 401, a pair of tension bands 410a and 410b are fitted in fitting grooves 425a and 425b formed on both side surfaces 423 of the block 420, respectively.

  In the first to third embodiments described above, the case where the group end block pitch is larger than the block pitch and smaller than twice the block pitch is described, but the present invention is not limited thereto. The group end block pitch may be any value other than a multiple of the block pitch.

  Further, in the first and third embodiments described above, the case where the dividing surface of the mold passes through the center position in the width direction of the high load transmission belt, and in the second embodiment, Although the case where the dividing surface of the mold is adapted to be along the end in the width direction of the tension band has been described, it is not limited thereto. For example, the dividing surface of the mold may be arranged along the width direction of the high load transmission belt.

  The block is made only of a synthetic resin material, and no insert material made of a metal such as an aluminum alloy is embedded therein. However, the insert material made of metal or the like here refers to a skeleton-like material that has almost the shape of a block.For example, a reinforcing material such as a short fiber or whisker that is added in a synthetic resin material is added. The addition does not depart from the scope of the present invention.

  As the block resin, polyamide resin, polyamideimide (PAI) resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polyimide (PI) resin, polyethersulfone (PES) resin, Synthetic resins such as polyetheretherketone (PEEK) resin are used, but among them, they have low friction coefficient, excellent wear resistance, rigidity and elasticity against bending, and can be easily damaged. Resin which does not end up is good, and it can be said that a polyamide resin is preferable.

  In the present invention, it is possible to mix a fibrous reinforcing material and a whisker-shaped reinforcing material in the synthetic resin forming the block as described above, and the fibrous reinforcing material is blended in the range of 15 to 40% by weight. To do. If it is less than 15% by weight, there is a problem that the reinforcing effect is small and the wear resistance of the block is not sufficient, and if it exceeds 40% by weight, it becomes difficult to add to the resin or injection molding becomes difficult. This is not preferable.

  Examples of the fibrous reinforcing material to be blended with the synthetic resin include aramid fibers, carbon fibers, glass fibers, polyamide fibers, and polyester fibers. Among them, by using a combination of nylon 46 and carbon fiber, which is a preferable example of the resin constituting the block, the carbon fiber can improve the water absorption defect of nylon 46 and greatly improve the rigidity. In addition, the wear resistance, impact resistance, and fatigue resistance of nylon 46 can be utilized. Of the carbon fibers, PAN-based carbon fibers are preferably used. Moreover, the toughness of a block improves by mix | blending an aramid fiber in combination with a carbon fiber, and abrasion resistance and impact resistance can be improved further.

  Here, the PAN-based carbon fiber used has good compatibility with the thermoplastic resin, and the carbon fiber used preferably has a length of 1 to 5 mm. If it is less than 1 mm, the block is not sufficiently reinforced, and if it exceeds 5 mm, kneading with the resin becomes difficult, and it is not preferable because it breaks and shortens during kneading.

  Moreover, you may mix | blend inorganic fibers, such as a zinc oxide whisker, a potassium titanate whisker, an aluminum borate whisker other than said organic fiber as said fibrous reinforcement. By blending these whiskers, warpage during molding and anisotropy of molding shrinkage are improved. Further, the anisotropy of strength such as block toughness and bending rigidity can be reduced and the friction coefficient is stabilized, so that the wear resistance is improved.

  Moreover, since the zinc oxide whisker has a high specific gravity and high rigidity, it is possible to reduce vibration during contact with the pulley and to reduce noise generation. In addition, when there are few compounding quantities of this zinc oxide whisker, the added effect does not express, and when too large, it cannot knead | mix and it becomes difficult to shape | mold.

  By adopting such a material structure, it has strength such as rigidity and toughness that can sufficiently withstand the side pressure received when it comes into contact with the pulley, has excellent wear resistance, and further, with respect to heat generated during friction. Therefore, the power received from the pulley can be efficiently transmitted to the tension belt as a tensile force, and a tension transmission type high load transmission belt can be configured.

  In addition to these, the lubricity of the block can also be improved by mixing at least one selected from molybdenum disulfide, graphite, and fluororesin. Examples of the fluororesin include polytetrafluoroethylene (PTFE), polyfluorinated ethylene propylene ether (PFPE), tetrafluoroethylene hexafluoropropylene copolymer (PFEP), polyfluorinated alkoxyethylene (PFA), and the like. .

  Examples of the elastomer used in the tension band include a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, rubber obtained by appropriately blending these, polyurethane rubber, and the like. As the core wire, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used. In addition to the core wire having a rope embedded in a spiral shape, a woven fabric, a knitted fabric, a metal thin plate, or the like of the above-mentioned fibers can also be used.

  The block used in the high load transmission belt according to the present invention is not limited to the form shown in the present embodiment.

(Embodiment 1) As Embodiment 1, a high load transmission belt having a structure as shown in FIG. 5 is used. Regarding the arrangement of the blocks, the number of blocks constituting one group is 17, the thickness of the blocks is 3 mm, the block pitch is 4 mm, and the group end block pitch is 5 mm. Therefore, the group pitch is 69 mm. The block is injection-molded so as to be fixed to the tension band at such a pitch, and a high-load transmission belt having a circumference of 690 mm is produced. In other words, ten groups composed of 17 blocks are formed in the tension band. Here, nylon 46 containing 30% by mass of carbon fiber is used as a block material.

  The above-described high-load transmission belt was wound around a drive pulley (effective diameter 46.3 mm) and a driven pulley (effective diameter 46.3 mm), and a running test was performed at a rotation speed of the drive pulley of 1000 to 5000 rpm. The result of the noise analysis is shown in FIG.

(Comparative Example 1) As Comparative Example 1, a high load transmission belt having the structure shown in FIG. 5 is used as in Example 1, but the blocks are arranged at an equal pitch over the entire circumference of the belt. Specifically, a high load transmission belt having a block thickness of 3 mm, a block pitch of 6 mm, and a peripheral length of 690 mm is produced. That is, the injection molding is performed so that 115 blocks are fixed to the tension band. And the driving | running | working test was done on the conditions similar to Example 1. FIG. The result of the noise analysis is shown in FIG.

(Comparative Example 2) As Comparative Example 2, a high-load transmission belt manufactured in the same manner as in Comparative Example 1 is used except that the block pitch is 3 mm. That is, the injection molding is performed so that 230 blocks are fixed to the tension band. And the driving | running | working test was done on the conditions similar to Example 1. FIG. The result of the noise analysis is shown in FIG.

Here, when the effective diameter of the pulley is D and the rotation speed is R, the block pitch frequency Fa of the high load transmission belt having a block pitch a can be expressed by the following (formula 4).
Fa = D × π × (R / 60) × (1 / a) (Formula 4)

  FIGS. 11A to 11C are graphs showing the magnitude of noise. The vertical axis represents the rotational speed R of the drive shaft, and the horizontal axis represents the frequency F. FIG. In FIG. 11B, three straight lines G, H, and I are observed. The straight line G corresponds to the block pitch frequency Fa calculated by (Equation 4) described above, the straight line H corresponds to twice that, and the straight line I corresponds to three times that. Similarly, the straight lines J and K observed in FIG. 11C respectively correspond to the block pitch frequency Fa calculated by the above-described (Expression 4) and twice the same. From the above, it can be seen that in Comparative Examples 1 and 2, a large noise is generated at the frequency resulting from the block pitch frequency.

  On the other hand, in FIG. 11A, a large number of straight lines are observed. Among these many straight lines, the straight line C is a straight line corresponding to the block pitch frequency Fa calculated by the above (formula 4), and the straight line E is a straight line corresponding to twice that, but FIG. , (C) are not observed as clear straight lines like the straight lines G, H, I, J, and K. Thus, in Example 1, it turns out that the frequency of noise is distributed suitably. As a result, the noise of the frequency resulting from the block pitch frequency is not noticeable.

It is a perspective view of the high load power transmission belt concerning a 1st embodiment of the present invention. It is II-II sectional drawing of the high load power transmission belt of FIG. It is a top view which shows the state by which the high load transmission belt was wound around the drive and the driven pulley. FIG. 4 is a cross-sectional view of the drive pulley of FIG. 3 taken along the line IV-IV. It is a schematic perspective view of the metal mold | die used with the manufacturing method concerning the 1st Embodiment of this invention. It is a front view of the division surface of the metal mold | die of FIG. It is VII-VII sectional drawing of the metal mold | die of FIG. It is width direction sectional drawing of the metal mold | die used with the manufacturing method concerning the 2nd Embodiment of this invention. It is a front view of the division surface of the metal mold | die used with the manufacturing method concerning the 3rd Embodiment of this invention. (A) is a perspective view of a modified example of the high load transmission belt shown in FIG. 1. (B) is a perspective view of another modified example of the high load transmission belt shown in FIG. 1. (A) is a graph which shows the result of the noise analysis of Example 1. FIG. (B) is a graph which shows the result of the noise analysis of the comparative example 1. FIG. (C) is a graph which shows the result of the noise analysis of the comparative example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High load transmission belt 10 Tension | tensile_strength 11 Elastomer 12 Core wire 13a, 13b Block fixing groove 14a, 14b Mold fitting groove 20 Block 20a, 20b Convex part 23 Side surface 30, 31 Mold 31 Tension band holding part 33 Cavity 34 Passage 35 Gate 36 Split surface

Claims (8)

In a high load transmission belt having a tension band and a plurality of blocks provided along the longitudinal direction of the tension band,
A plurality of groups including a predetermined number of the blocks arranged at a predetermined pitch are formed, and a pitch between the blocks arranged at adjacent end portions of the adjacent groups is different from a multiple of the predetermined pitch. A high load transmission belt characterized by having a value.   2. The high load transmission belt according to claim 1, wherein a pitch between the blocks arranged at adjacent end portions of the group is a value smaller than twice the predetermined pitch. In a method of manufacturing a high load transmission belt having a tension band and a plurality of blocks provided along the longitudinal direction of the tension band,
A tension band holding portion, and a plurality of the block forming cavities arranged so that a predetermined number of the blocks formed at a predetermined pitch are fitted to the tension band held by the tension band holding portion; Using a mold with
By injecting resin into the cavity in the mold in a state where the tension band is set in the tension band holding portion, a group consisting of a predetermined number of the blocks is formed and at the same time the group of the group Including attaching each block,
By repeating the step a plurality of times, the plurality of groups are formed such that a pitch between the blocks arranged at adjacent end portions of the adjacent groups has a value different from a multiple of the predetermined pitch. A method for producing a high-load transmission belt, which is characterized.   4. The method for manufacturing a high load transmission belt according to claim 3, wherein the dividing surface of the mold is provided so as to pass through a center position in the width direction of the high load transmission belt.   4. The method for manufacturing a high load transmission belt according to claim 3, wherein a dividing surface of the mold is provided along an end in a width direction of the tension band.   The high load transmission according to any one of claims 3 to 5, wherein the tension band holding portion of the mold is configured to be able to change an interval in a thickness direction of the tension band. A method for manufacturing a belt.   The method for manufacturing a high-load transmission belt according to any one of claims 3 to 6, wherein a pitch between the blocks arranged at adjacent end portions of the group is larger than the predetermined pitch. .   The high load transmission according to any one of claims 3 to 7, wherein a pitch between the blocks arranged at adjacent end portions of the group is smaller than twice the predetermined pitch. A method for manufacturing a belt.

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