JP2005201401A - Manufacturing method for high load transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a high load transmission belt which materializes outstanding reduction in the time required for manufacturing a belt, and obtains a belt having high strength and long service life while eliminating work for fitting each block to a tension band in a work for mounting the block to the tension band. <P>SOLUTION: In the manufacturing method for the high load transmission belt 1 in which the block 2 is mounted to the tension band 3, metal molds 30, 31 having tension band retaining parts 32 and cavities 33 for molding the block are used. The block 2 is molded and mounted to the tension band 3 at the same time by injecting a resin to the cavities 33 in the metal mold in the state that the tension band 3 equipped with a sheet-metal insert material 8 is set. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for manufacturing a high-load transmission belt in which a plurality of blocks are fixed along a longitudinal direction of a tension band, and a high-load transmission belt, which can be efficiently manufactured in a shorter time.

  The belt used in the belt-type continuously variable transmission is used by being wound around a transmission pulley that changes the effective diameter of the pulley by changing the V groove width of the pulley and adjusts the transmission ratio. Because the side pressure from the belt increases, the belt must withstand a large side pressure. In addition to continuously variable speed applications, it is necessary to use a belt that can withstand a high load, especially for high-load transmission applications where the life of conventional rubber belts is too short.

  Among those used as such belts, there is a tensile transmission type high load transmission belt in which the block is fixed to the center belt (tensile belt) and the strength in the belt width direction is increased. As a specific configuration, A block made of elastomer that is relatively harder than the elastomer used for the center belt (tension belt) is secured to the center belt with a core wire embedded in an elastomer such as rubber using a fastening material such as a bolt or rivet. There is something fixed.

  As the required quality of the block used for such a tension transmission type high load transmission belt, since it is intended for high load transmission in friction transmission as described above, bending fatigue, wear resistance, heat resistance, It is necessary to have a good balance of properties such as rigidity and impact resistance. Another important factor is not to wear the pulley.

  An example of a high load transmission belt that satisfies these requirements is disclosed in Japanese Patent Application Laid-Open No. 63-34342. This belt uses a double-structured block in which the part where the block and pulley come into contact is coated with an insert material made of metal or the like by a resin molding material in which a rubber component is added to a phenolic resin component. It is.

  In Patent Document 1, a phenolic resin is mixed with 25 to 60 parts by weight of a fiber containing two fibers of carbon fiber and aramid fiber using acrylonitrile-butadiene rubber as a matrix, and the carbon fiber has an onion structure. A high-load transmission belt using a block using a phenolic resin having a crystal layer thickness of 25 to 200 μm is disclosed.

  For this reason, for example, since the belt disclosed in Patent Document 2 uses an aluminum alloy or the like as an insert material, if it rotates at a high speed, a large centrifugal force is applied due to its weight, and a large tension acts on the belt. As a result, there has been a problem that the belt is prematurely damaged.

  In addition, the amount of heat generated between the pulley and the block increases due to the high-speed rotation. Therefore, in the block mainly composed of phenolic resin as disclosed in Patent Document 1, the phenolic resin is inferior in impact resistance. However, the belt may be damaged. Unless this was improved, the above-described demand for a high load transmission belt could not be satisfied at a high level. In addition, since the phenol resin is a thermosetting resin, there is a problem that the molding cycle becomes long and the recyclability is inferior.

  Therefore, it is conceivable to use a block made of a thermoplastic resin material without inserting an insert made of an aluminum alloy or the like embedded in the block in order to reduce the weight of the block.

Patent Document 3 discloses a belt manufacturing method in which a block is formed by injection molding in a state where a center belt (tension band) is installed in a mold.
Further, Patent Document 4 and Patent Document 5 disclose a belt using a sheet metal insert as an insert, and the use of a sheet metal insert having a U-shaped cross section can provide sufficient strength. A belt that does not impair weight reduction is described.

Japanese Examined Patent Publication No. 7-110900 Japanese Patent Laid-Open No. 63-34342 JP 2003-202054 A JP-A-61-140646 JP-A-61-144451

  However, the production of a belt equipped with such a block requires an operation of fitting the blocks one by one in a tension band, which is very laborious to produce. This is disadvantageous in terms of manufacturing cost, and there is a problem that the belt becomes expensive.

  Moreover, in patent document 3, the process of mounting a block separately formed on the center belt (tension band) can be omitted by injecting resin into a mold having a center belt (tension band) and molding the block. Therefore, the manufacturing cost can be greatly reduced. However, since the block is a molded body made only of a resin, there is a problem that the block has a problem of strength and is difficult to use in applications in which a large torque is transmitted.

  Patent Documents 4 and 5 disclose a belt using a sheet metal core material coated with an elastic body as a block.

  In manufacturing a belt of the type in which such a block is mounted on a tension band, the present invention is very simple and can perform a high load transmission belt in a short time by simultaneously forming the block and mounting the block on the tension band. It is an object of the present invention to provide a method for producing a high-load transmission belt that can be manufactured, and that has high block strength and excellent durability.

  In order to solve the above-mentioned problems, claim 1 of the present invention provides a high-load transmission belt provided with a tension band and a plurality of blocks in which an insert material is arranged in a resin material along the longitudinal direction of the tension band. In the method, the mold has a tension band holding part and a cavity for molding a block arranged so that the molded block is fitted in a predetermined position of the tension band held by the tension band holding part. The tension band is set in the tension band holding section and the resin is injected into the cavity in the mold with the sheet metal insert material attached to the tension band, so that the block is simultaneously molded into the tension band. The process of attaching is included.

  In claim 2, the insert material includes a reinforcing portion for reinforcing the strength of the block and a mounting portion for fixing to the tension band, and the reinforcing portion is subjected to sheet metal processing, and the mounting portion is subjected to sheet metal processing. This is a manufacturing method of a high load transmission belt that is not performed.

  The belt can be manufactured because the block can be molded and the block can be attached to the tension band at the same time, and the work of attaching the block to the tension band is not required to fit each block into the tension band. The time required for the process can be greatly shortened, and because the resin is injection molded with a sheet metal insert in the tension band, the strength can be improved without hindering the weight reduction of the block. And a high load transmission belt having excellent durability can be obtained.

  In addition, by using a sheet metal insert material that has been deep-drawn with a lower beam, the strength of the insert material can be further improved, and it can be used sufficiently even in applications that transmit high torque. It can be a transmission belt.

  FIG. 1 is a perspective view showing an example of a mold used in the method for manufacturing a high load transmission belt according to the present invention, FIG. 2 is a front view of the mold when opened, and FIG. 3 is a state where the mold is closed. FIG. 4 is a side sectional view showing another example of FIG. 3. FIG. 5 is a perspective view showing an example of a high load transmission belt manufactured by the manufacturing method of the present invention, and FIG. 6 is a side sectional view of the high load transmission belt.

  The high load transmission belt manufactured by the manufacturing method of the present invention is, for example, as shown in FIGS. 5 and 6. The high load transmission belt 1 has a core wire 5 embedded in an elastomer 4 in a spiral shape. And a plurality of blocks 2 that are fitted in recesses 6 formed at a predetermined pitch on the upper surface of the tension band 3 and are locked and fixed. Both side surfaces 2a and 2b of the block 2 are inclined surfaces that engage with the V-grooves of the pulley, and receive power from the driven pulley to pull the tension band 3 that is locked and fixed. The power of the driving pulley is transmitted to the driven pulley.

  In the block 2, as shown in FIG. 5, the upper beam portion 11 and the lower beam portion 12, and both side portions 13 and 14 are integrally formed around the tension band 3. The center of the block 2 has an opening 15 into which the tension band 3 is fitted. The upper surface and the lower surface in the opening 15 have a groove 6 provided on the upper surface of the tension band 3 and a groove 7 provided on the lower surface. Convex ridges 16 and 17 are formed to be engaged with each other. Further, an insert material 8 made of sheet metal is embedded inside, and the strength of the block 2 is considerably high. Further, since it is made of sheet metal, its weight is small relative to its strength and does not hinder the weight reduction of the belt.

  Examples of the material that can be used for the sheet metal insert 8 include a steel plate (stainless steel plate, spring steel plate, etc.), an aluminum alloy plate, a magnesium alloy plate, and the like, and the thickness is 0.1 mm to 0.5 mm. Ranges are used. A portion of the metal plate that needs to have strength is subjected to sheet metal processing such as drawing or bending. By performing the sheet metal processing, the strength is greatly improved and it can be sufficiently used for applications that transmit high torque. In the manufacturing method of the present invention, since the insert material 8 is previously attached to the tension band 3 and the resin is injection-molded, the insert material 8 is easily attached to the tension band 3 to some extent. It is preferable that a portion not subjected to sheet metal processing as described above can be provided so that the metal plate can be easily mounted using the spring property.

  The insert material 8 subjected to sheet metal processing is, for example, as shown in FIG. 7 and includes a lateral reinforcing portion 8a subjected to sheet metal processing and a mounting portion 8b not subjected to sheet metal processing. Then, as shown in FIG. 8, the tension band 3 is mounted so as to sandwich the tension band 3 using the spring property of the mounting portion 8 b. By using such an insert material 8, the strength of the block 2 can be greatly improved in the reinforcing portion 8a, and in the mounting portion 8b, the insert material 8 is attached to the tension band 3 by utilizing the spring property. It can be done easily.

  The shape of the insert material 8 is not limited to that shown in FIGS. 7 and 8 and can take various shapes. In FIG. 7, the reinforcing portion 8a is located on the lower side of the block 2. However, for example, the reinforcing portion 8a is located only on the upper side. It may be something like

  In manufacturing a high-load transmission belt in which a tension band is fitted into a block as described above, a pair of molds 30 and 31 are used as shown in FIGS. 1, 2, and 3. , 31 has a tension band holding portion 32, and a cavity 33 for forming the block 2 is formed in a state where the pair of molds 30, 31 are joined together. Resin is injected into the cavities 33 in the molds 30 and 31 while being set in the holding part 32. The tension band 3 has recesses 9 and 10 to be fitted to the tension band holding part 32 of the mold between the recesses 6 and 7 to be fitted to the block 2 on the upper and lower surfaces, and the block 2 is injection molded. The tension band 3 is positioned at the time of molding.

  The cavity 33 is arranged so as to surround the tension band 3 with the tension band 3 fitted in the tension band holding part 32. When the block 2 is formed by the cavity 33, the block 2 is formed in the tension band 3 with the concave strip portion 6, 7 is formed in a state of being fitted.

  Through the steps as described above, the block 2 can be attached to the tension band 3 at the same time as the block 2 is molded.

  Conventionally, in the manufacture of such a high load transmission belt, the tension band 3 is manufactured, and the block 2 is manufactured separately, and then the block 2 is fitted into the tension band 3 one by one. Although much time has been taken for the work of fitting the block 2 into the tension band 3, since the block 2 is formed at a predetermined position of the tension band 3 by adopting the above manufacturing method, When the block 2 is completely formed, the block 2 is fitted into the tension band 3, so that the work of fitting the block 2 into the tension band 3 is not required, so that the time required for manufacturing is greatly reduced. Is something that can be done.

  Further, as shown in FIG. 3, the mold 30 and the mold 31 have a dividing surface 36 positioned so that a parting line is formed at the center of the upper beam portion 11 and the lower beam portion 12 of the block. By doing so, the side surfaces 2a and 2b of the block that come into contact with the pulley when the belt travels can be finished to a smooth surface, so that the problem of noise and wear in the initial belt travel can be solved.

  The position of the dividing surface 36 is located near the center of the tension band 3 in FIG. 3. However, if the side surfaces 2a and 2b of the block are finished smoothly, as shown in FIG. It is also possible to position it. By doing so, the amount of protrusion from the mold 31 of the tension band 3 is reduced with the tension band 3 inserted into the mold 31, and the protruding tension band 3 when the mold 30 is aligned is bent or caught by the mold. It can be said that this is a preferable form in which damage or the like is prevented.

  In the example shown in FIG. 2, the cavities 33 provided in the molds 30 and 31 are five, and the number of blocks that can be molded at one time is five. Therefore, after forming five blocks, the belt is once removed from the mold, and the five blocks are rotated in the direction of the arrow in FIG. And 5 blocks 2 are formed at the next position. By repeating such an operation, the entire block 2 around the belt is molded to complete the belt.

  The tension band does not need to be fixed at a place other than the cavity 33 for molding the block 2, and a passage 34 that is slightly wider than the general shape of the belt is formed as a belt escape location when the mold is closed.

  In each cavity 33, an injection molding gate 35 is arranged near the upper center of the block, and the block 2 is formed by injecting molten resin. The position of the gate 35 is provided in the vicinity of the upper center, but is not limited to this position, and can be arranged at an arbitrary position.

  When the molding of the block is completed, the molds 30 and 31 are opened, and the block 2 is removed from the mold. For removal, it is convenient to use an eject pin protruding from the mold. For example, as shown in the block of FIG. 9, the vertical surface portion 2c is formed at the vertical positions of the inclined side surfaces 2a and 2b of the block 2. It is good also as a location where an eject pin contacts.

  In such a high load transmission belt 1 in which the block 2 is attached to the tension band 3, the pitch of the block 2 (interval between the blocks 2 attached to the tension band 3) is related to noise problems and the pitch is too large. And noise will increase. However, on the other hand, if the thickness of the molds existing between the blocks when the blocks 2 are formed becomes too thin, the molds are deformed by the injection pressure, leading to deformation of the blocks 2, which is not preferable. Therefore, the thickness of the mold between the block 2 and the block 2 is set to 1/6 to 3/2 of the thickness of the block 2. However, as shown in FIG. 2, in some cases, such as the number of blocks formed at one time out of all the blocks of the high load transmission belt 1, it is more preferably 1/2 to 3/2.

  If the thickness of the mold between the block 2 and the block 2 exceeds 3/2 of the block thickness, the pitch of the block becomes too large, causing problems of belt strength and noise. Mold deformation will occur.

  In the above description, the block 2 is formed five at a time, and all of the blocks 2 are formed in order to complete the high load transmission belt 1, but a mold having the same number of cavities as the total number of the blocks 2 is used. You may mold all at once.

  When the mold is provided with the same number of cavities 33 as the total number of blocks, and all the blocks 2 are molded at once, the cavities 33 are all located next to each other, and the pressure in the cavities 33 is substantially constant. Therefore, even if the thickness of the mold between the blocks 2 is small, the mold is hardly deformed. Therefore, the block can be sufficiently formed in the range of 1/6 to 1/2 of the block thickness.

  The high load transmission belt applicable to the present invention is not limited to the example shown in FIG. 5, and can take various forms. The belt shown in FIG. 10 has substantially the same shape as the belt shown in FIG. 5, but has through holes 18 at the same pitch as the block attached to the center in the width direction of the tension band 3. The resin is connected 19 through the through hole 18 when the resin is molded.

  Thus, the resin 19 that forms the block is connected through the through-holes 18 provided in the tension band 3 so that the fixing force between the block 2 and the tension band 3 becomes stronger. If the belt 1 continues to run for a long period of time, the block 2 and the tension band 3 will rattle, causing the noise of the belt 1 to increase, the block 2 to be damaged, and the tension band 3 to be cut off. Although it may lead to failure, the life of the belt 1 can be extended by increasing the fixing force of the block 2 and the tension band 3.

  In the example of FIG. 10, the number of the through holes 18 provided in the tension band 3 per block 2 is one, but the number is not limited to one, and a plurality of holes such as two or three are provided. It is also possible to provide.

  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 polyamide resin, especially nylon 46 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 toughness and bending rigidity of the block 2 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. The power received from the pulley can be efficiently transmitted to the tension band 3 as a tensile force, and a tensile transmission type high load transmission belt can be configured.

  In addition to these, the lubricity of the block 2 can be improved by mixing at least one selected from molybdenum disulfide, graphite, and fluorine-based resin. 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 4 used for the tension band 3 include a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, or a rubber or polyurethane rubber obtained by appropriately blending them. . As the core 5, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used. The core wire 5 may be made of a woven fabric, knitted fabric, metal thin plate, or the like of the above-mentioned fiber other than a rope embedded in a spiral shape.

  The present invention can be applied to the manufacture of belts that change the effective diameter of pulleys and transmit large torque, such as continuously variable transmissions for automobiles, motorcycles, and agricultural machines.

It is a general | schematic perspective view of the manufacturing apparatus used with the manufacturing method of this invention. It is the front view seen from the place which opened the metal mold | die. It is the sectional side view seen in the state where a metal mold was closed. It is a sectional side view which shows another example in FIG. It is a perspective view of the high load power transmission belt manufactured by the manufacturing method of this invention. It is a sectional side view of a high load power transmission belt. It is a perspective view which shows an example of insert material. It is sectional drawing of the place which mounted | wore the tension material with the insert material. It is a front view which shows another example of a block. It is a perspective view which shows another example of a high load power transmission belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High load power transmission belt 2 Block 3 Tension band 4 Elastomer 5 Core wire 6 Concave part 7 Concave part 8 Insert material 8a Reinforcement part 8b Mounting part 9 Concave part 10 Concave part 11 Upper beam part 12 Lower beam part 30 Mold 31 Mold 32 Tension band holding part 33 Cavity 34 Passage 35 Gate 36 Dividing surface

Claims (2)

  In a manufacturing method of a high load transmission belt provided with a tension band and a plurality of blocks in which an insert material is arranged in a resin material along a longitudinal direction of the tension band, the mold is attached to the tension band holding part and the tension band holding part. It has a cavity for molding a block arranged so that the molded block is fitted in a predetermined position of the held tension band, and the tension band is set in the tension band holding part and the tension band A method of manufacturing a high-load transmission belt, comprising a step of molding a block and simultaneously attaching the block to a tension band by injecting resin into a cavity in a mold with a sheet metal insert attached. The insert material consists of a reinforcing part for reinforcing the strength of the block and a mounting part for fixing to the tension band, the reinforcing part is subjected to sheet metal processing, and the mounting part is not subjected to sheet metal processing Item 2. A method for manufacturing a high-load transmission belt according to Item 1.

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