JP2003322217A - High-load transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-load transmission belt with largely improved bending modulus, impact resistance, abrasion resistance, etc., to be sufficiently durable to high-load applications, while achieving lightness of blocks. <P>SOLUTION: This high-load transmission belt 1 comprises a plurality of blocks 2 provided at prescribed pitch along a length direction of tension belts 3a and 3b. The block 2 comprises a synthetic resin material without including an insert. Carbon nanotubes are blended in the synthetic resin forming the block 2. The synthetic resin material is nylon 46, and blended quantity of the carbon nanotubes is 20-35 mass%. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high load transmission belt in which blocks are fixed at a predetermined pitch along the longitudinal direction of a tension band, and more specifically, it is lightweight and has a bending elastic modulus,
The present invention relates to a high load transmission belt having excellent impact resistance, abrasion resistance and dimensional accuracy.

[0002]

2. Description of the Related Art A belt used in a belt type continuously variable transmission is used by being wound around a variable speed pulley in which the effective groove diameter of the pulley is changed by changing the V groove width of the pulley to adjust the gear ratio. However, since the lateral pressure from the pulley increases, the belt must withstand the large lateral pressure. In addition to the use of continuously variable transmission, it is necessary to use a belt that can withstand a particularly high load in a high load transmission application in which a normal rubber belt has a too short life.

Among the belts used as such a belt, there is a tension transmission type high load transmission belt in which a block is fixed to a center belt to increase the strength in the belt width direction. There is a center belt in which wires are embedded in an elastomer such as rubber, and a block made of an elastomer that is relatively harder than the elastomer used for the center belt is fastened and fixed by using a fastening material such as bolts and rivets. .

As the required quality of such a block of the tension transmission type high load transmission belt, since the purpose is to transmit a high load in friction transmission as described above, bending fatigue resistance, wear resistance, heat resistance It is necessary to maintain a good balance of properties such as rigidity and impact resistance. It is also an important factor to keep the pulleys from wearing out.

As a high load transmission belt satisfying these requirements, there is, for example, one disclosed in Japanese Patent Laid-Open No. 63-34342. This belt uses a block having a double structure in which the contact portion between the block and the pulley is covered with an insert material formed of metal or the like by a resin molding material in which a rubber component is added to a phenolic resin component. Is.

In Japanese Patent Publication No. 7-110900, a phenolic resin is blended with a fibrous filler of 25 to 60 parts by weight containing two fibers of carbon fiber and aramid fiber with acrylonitrile-butadiene rubber as matrix. , Carbon fiber has an onion structure, and the crystal layer thickness is 25
A high load transmission belt using a block using a phenolic resin having a thickness of 200 μm is disclosed.

[0007]

By the way, recently, due to the diversification of needs, there is a demand for a high load transmission belt, which has a high load but a slightly lower load than the conventional one, and can be rotated at a high speed. Is becoming.

Therefore, for example, JP-A-63-34342 is used.
Since the belt disclosed in the publication uses an aluminum alloy or the like as an insert material, when it is rotated at a high speed, a large centrifugal force is applied due to its weight, and a large tension acts on the belt to The problem of premature damage began to occur.

Further, due to the high speed rotation, the amount of heat generated between the pulley and the block also increases, and therefore, Japanese Patent Publication No. 7-1
In a block containing a phenolic resin as a main component as disclosed in Japanese Patent No. 10900, the phenolic resin may have poor impact resistance, and the belt may be damaged. Without improving this, it was not possible to satisfy the requirements for the above-mentioned high load transmission belt at a high level. Further, since the phenol resin is a thermosetting resin, there are problems that the molding cycle becomes long and the recyclability is poor.

Therefore, the present invention has been made in view of the above-mentioned problems, and has sufficient strength even when the block weight is reduced and high-speed rotation is performed, and it is demanded as a high-load transmission belt. It is an object of the present invention to provide a tension transmission type high load transmission belt which can satisfy the existing conditions at a high level.

[0011]

In order to solve the above-mentioned problems, a high load transmission belt according to claim 1 of the present invention comprises a tension band,
In a high load transmission belt including a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the tension band, the blocks are made of a synthetic resin material in which an insert material is not embedded, and the blocks are composed of a synthetic resin material. A high load transmission belt characterized in that the resin is blended with carbon nanotubes.

Although it is possible to reduce the weight by using a block in which the insert material is not embedded, the performance such as the bending elastic modulus, the impact resistance and the abrasion resistance of the block may be insufficient. By doing so, it is possible to provide a high load transmission belt which can greatly improve performances such as flexural modulus, impact resistance, and wear resistance, and which can sufficiently endure even when used in high load applications. Moreover, since carbon nanotubes can be reinforced with a large number of fibers in a smaller amount than the case of blending ordinary carbon fibers, the reinforcing effect can be enhanced.

In claim 2, the synthetic resin material is nylon 4
It is a high load transmission belt made of 6 resin.

By using nylon 46 as the synthetic resin material, the toughness is higher than that of other polyamides, and the resin is less likely to be damaged or cracked, so that the life of the high load transmission belt is further improved.

According to the third aspect of the present invention, a high load transmission belt having a carbon nanotube content of 20 to 35% by mass is provided, so that a sufficient reinforcing effect can be obtained and the block can be molded without problems.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a high load transmission belt 1 according to the present invention.
It is a perspective schematic diagram showing an example. The high-load transmission belt 1 of the present invention has two tension bands 3a and 3b of the same width formed by embedding a core wire 5 in an elastomer 4 in a spiral shape, and fixed to the tension bands 3a and 3b. And a plurality of blocks 2 that are present. Both sides 2 of this block 2
a and 2b are inclined surfaces that engage with the V groove of the pulley, and receive power from the driven pulley,
The tension bands 3a and 3b that are locked and fixed are pulled to transmit the power of the driving pulley to the driven pulley.

As shown in FIG. 1, the block 2 includes an upper beam portion 11 and a lower beam portion 12, and an upper and lower beam portions 11,
It is composed of a center pillar 13 that connects the central portions of 12 to each other.
Grooves 14 and 15 into which a and 3b are fitted are formed. Further, on the groove upper surface 16 and the groove lower surface 17 in the groove 15, a groove portion 18 provided on the upper surface of the tension band 3 and a groove portion 19 provided on the lower surface thereof.
It is adapted to be engaged with the ridges 20 and 21 which are engaged with.

FIG. 2 shows another example of the belt, which is a pair of side pillars 3 extending upward from both ends of the beam portion 31.
2, 33 extend, and lock portions 34, 35 extending from the upper ends of the side pillars 32, 33 toward the center of the block 2 are provided so as to face each other. The beam portion 31, the side pillars 32 and 33, and the lock portions 34 and 35 form a fitting groove 30 into which the tension bands 3a and 3b are fitted. In this fitting groove 30,
The tension bands 3a and 3b are inserted and attached through the opening between the lock portions 34 and 35. Further, convex portions 37 are provided on the fitting groove 30 side of the lock portions 34 and 35, respectively.
The convex portions 37 fit into the concave portions 36 provided in the tension bands 3a and 3b at a predetermined pitch. As a result, the tension bands 3a and 3b are in a state in which they are hard to come off from the block 2 after mounting.

This block 2 is made only of synthetic resin material, and no insert material made of metal such as aluminum alloy is buried. However, the insert material made of metal or the like here refers to a skeleton that is almost in the shape of a block by itself, for example, a reinforcing material such as short fibers or whiskers added in a form mixed in a synthetic resin material. Addition does not depart from the scope of the invention.

Polyamide resin, polyamideimide (PAI) resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polyimide (P) can be used as the block resin.
I) Resins, polyether sulfone (PES) resins, polyether ether ketone (PEEK) resins and other synthetic resins are used.

In the case of such a block in which the insert material is not embedded, since the block is not reinforced by the insert material, the block is likely to be deformed due to the load on the belt, and when the deformation of the block becomes large, the transmission of the belt is increased. As the performance deteriorates, the deterioration of the block due to repeated deformation is severe and the life of the belt is shortened.

Therefore, in the present invention, carbon nanotubes are blended with the synthetic resin forming the block 2. A carbon nanotube has a diameter of about 0.5 to 10
It is a cylindrical material made of only carbon atoms having a wavelength of 0.5 nm and a length of 0.5 to 10 μm, and is a multilayer or a single layer. By blending such carbon nanotubes, even with a small blending amount, it is reinforced with a large number of fibers, so that a large reinforcing effect can be obtained and also the effect of lowering the friction coefficient can be obtained. Performance such as rate, impact resistance, and wear resistance can be improved.

The content of carbon nanotubes is preferably in the range of 20 to 35% by mass.
If it is less than 0% by mass, there is a problem that the reinforcing effect is small and the abrasion resistance of the block is insufficient, and if it exceeds 35% by mass, it becomes difficult to mix it with the resin or injection molding becomes difficult. It is not preferable because there is a problem of.

In the present invention, carbon nanotubes are blended in the synthetic resin forming the block as described above, but it is possible to blend a whisker-like reinforcing material in addition to this, specifically, zinc oxide. Inorganic fibers such as whiskers, potassium titanate whiskers, and aluminum borate whiskers may be added. Of these, zinc oxide whiskers are preferably used. Zinc oxide whiskers have a three-dimensional shape with hands extending in four directions in a tetrapot shape. This zinc oxide whisker alone has excellent heat resistance and abrasion resistance, but since it has a tetrapod-like three-dimensional shape as described above, when it is blended with carbon fiber, the orientation of carbon fiber Is suppressed, and the anisotropy of warpage and molding shrinkage during molding is improved. Further, since the orientation of the carbon fibers can be reduced in this way, the anisotropy of strength such as toughness and bending rigidity of the block 2 can be reduced, and the friction coefficient is stable, so that the wear resistance is improved. To do.

Further, since the zinc oxide whisker has a high specific gravity and a high rigidity, it is possible to reduce the vibration at the time of contact with the pulley and to reduce the noise generation. When the amount of this zinc oxide whisker is small, the effect of addition is not exhibited, and when it is too large, kneading cannot be performed and molding becomes difficult.

By adopting such a material constitution,
It has strength such as rigidity and toughness that can withstand the lateral pressure that it receives when it comes into contact with the pulley, and it has excellent wear resistance.
Furthermore, it becomes possible to make the block strong against heat generated during friction, and the power received from the pulley can be efficiently transmitted to the tension bands 3a and 3b as a tensile force.
A tension transmission type high load transmission belt can be configured.

In addition to these, molybdenum disulfide,
The lubricity of the block 2 can also be improved by mixing at least one selected from graphite and fluorine resin. Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), polyfluoroethylene propylene ether (PFPE), tetrafluoroethylene hexafluoropropylene copolymer (PFEP), polyfluoroalkoxyethylene (PFA), and the like. .

What is used as the elastomer 4 of the tension bands 3a, 3b is a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, or a rubber or polyurethane in which these are appropriately blended. Examples thereof include rubber. As the core wire 5, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used. Further, as the core wire 5, other than the one in which the rope is embedded in a spiral shape, a woven cloth, a knitted cloth, a metal thin plate or the like of the above fibers can be used.

[0030]

Example Next, a belt using a block made by mixing a predetermined amount of carbon nanotubes and a belt using a block made by mixing ordinary carbon fibers were run to obtain durability time and I compared the noise and the amount of block wear.

(Example 1) Nylon 46 was used as the resin constituting the block, and the diameter was 5 nm and the length was 0.7 μm.
20 mass% of carbon nanotubes of m were blended to form a block by injection molding, and the block was fitted into a tension band to produce a high load transmission belt as shown in FIG. The belt pitch width is 22 mm, the pitch circumference is 831 mm, and the block pitch is 3 mm.

This belt was run, and the durability time, noise during running, and the amount of wear on the side surface of the block 100 hours after the start of running were measured. The running conditions are high torque conditions as shown in Table 1. The results of the running test are shown in Table 2.

[0033]

[Table 1]

Example 2 A high load transmission belt was prepared under the same conditions as in Example 1 except that the blending amount of carbon nanotubes was 25% by mass. The belt was run under the running conditions shown in Table 1, and the running time, noise during running, and running start 10
The amount of wear on the side surface of the block after 0 hour was measured. The results of the running test are shown in Table 2.

Example 3 A high load transmission belt was prepared under the same conditions as in Example 1 except that the amount of carbon nanotubes blended was 30% by mass. The belt was run under the running conditions shown in Table 1, and the running time, noise during running, and running start 10
The amount of wear on the side surface of the block after 0 hour was measured. The results of the running test are shown in Table 2.

(Example 4) A high load transmission belt was prepared under the same conditions as in Example 1 except that the blending amount of carbon nanotubes was 35% by mass. The belt was run under the running conditions shown in Table 1, and the running time, noise during running, and running start 10
The amount of wear on the side surface of the block after 0 hour was measured. The results of the running test are shown in Table 2.

Example 5 A high load transmission belt was prepared under the same conditions as in Example 1 except that the blending amount of carbon nanotubes was 40% by mass. The belt was run under the running conditions shown in Table 1, and the running time, noise during running, and running start 10
The amount of wear on the side surface of the block after 0 hour was measured. The results of the running test are shown in Table 2.

Comparative Example A high load transmission belt was prepared under the same conditions as in Example 1 except that 20% by mass of nylon 46 was mixed with carbon fibers having a diameter of 7 μm and a length of 6 mm.
The belt was run under the running conditions shown in Table 1, and the durability time, the noise during running, and the wear amount of the side surface of the block 100 hours after the start of running were measured. The results of the running test are shown in Table 2.

[0039]

[Table 2]

As can be seen from the results in Table 2, Examples 1 to 5 of the present invention have a long life, low noise, and a small amount of block wear even under high torque conditions.
Among them, Examples 2 to 5 continue to run without abnormality even after 300 hours, and among them, Examples 2 to 4 are particularly preferable because they have good moldability.

On the other hand, in the comparative example in which ordinary short carbon fibers are blended, the slip is large and the blocks melt in a short time to reach the end of life and the belt is cut. This comparison confirms the effect of using carbon nanotubes rather than ordinary carbon short fibers.

[0042]

The present invention is configured as described above,
In a high load transmission belt composed of a tension band and a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the tension band, the block is made of a synthetic resin material in which an insert material is not embedded, A high-load transmission belt characterized in that carbon nanotubes are mixed in the synthetic resin forming the.

Although it is possible to reduce the weight by using a block in which the insert material is not embedded, the performance such as bending elastic modulus, impact resistance, and abrasion resistance of the block may be insufficient, but the carbon nanotube is mixed. By doing so, it is possible to provide a high load transmission belt which can greatly improve performances such as flexural modulus, impact resistance, and wear resistance, and which can sufficiently endure even when used in high load applications. Moreover, since carbon nanotubes can be reinforced with a large number of fibers in a smaller amount than the case of blending ordinary carbon fibers, the reinforcing effect can be enhanced.

In claim 2, the synthetic resin material is nylon 4
It is a high load transmission belt made of 6 resin.

By using nylon 46 as the synthetic resin material, the toughness is higher than that of other polyamides, and the damage and cracking of the resin are less likely to occur, so that the life of the high load transmission belt is further improved.

According to the third aspect of the present invention, a high load transmission belt having a carbon nanotube content of 20 to 35% by mass is provided, so that a sufficient reinforcing effect can be obtained and the block can be molded without problems.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of a high load transmission belt according to the present invention.

FIG. 2 is a schematic perspective view showing another example of the high load transmission belt according to the present invention.

[Explanation of symbols]

1 High load transmission belt 2 blocks 3a tension band 3b tension band 4 Elastomer 5 cores 11 Upper beam section 12 Lower beam part 13 center pillars 14 Mating groove 15 Fitting groove

Claims (3)

[Claims] 1. A high-load transmission belt comprising a tension band and a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the tension band, wherein the block is made of a synthetic resin material in which an insert material is not embedded. The high load transmission belt is characterized in that carbon nanotubes are mixed in the synthetic resin forming the block. 2. The high load transmission belt according to claim 1, wherein the synthetic resin material is nylon 46 resin. 3. The blending amount of carbon nanotubes is 20 to
The high load transmission belt according to claim 1 or 2, wherein the content is 35% by mass.