JP2002364711A - V-belt for high load transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce heat generation of a belt and prevent breakage of a reinforcement of a block under a high speed travel condition of the belt, in a V-belt for high load transmission which comprises a left and a right tension band whose upper and lower surfaces each have recessed portions, and many blocks whose left and right sides are press-fitted with the respective tension bands, and in which the press fitting of the tension band in a fitting portion of each block fixedly engages each block with the tension band so that their sides are brought into contact with a pulley groove surface. SOLUTION: A back portion of the fitting portion 8 of each block 7 is provided with a lower back butt surface 16, and a lower back butt surface angle αmade by the lower back butt surface 16 and a vertical plane P is set in relation to a belt side angle β to satisfy β-3<α<β+3, so that a proper angle relation is established to a lower back butt portion 5 of the tension band 1. A thickness of resin over the reinforcement 12 is set at 0.3 mm or larger at least at an upper and a lower end position of the lower back butt surface 16 of the fitting portion 8, so that stress concentration is prevented on edge portions formed at the upper and lower end positions of the lower back butt surface 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a high-load transmission V-belt.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Laid-Open No. 1-55344.
No., Japanese Unexamined Utility Model Publication No. 6-69490, Japanese Unexamined Patent Publication No. 5-272595.
As shown in each of the publications, a high load transmission V-belt in which a number of blocks are locked and fixed to a tension band by using a block and an uneven engagement structure of the tension band is well known. Used in the field of transmissions. In this type of V-belt, each block is fixed to the tension band by a physical engagement state (engagement state), not by adhesion, in order to ensure the ease of bending. This belt is provided with a pair of left and right tension bands arranged in the belt width direction. On the upper and lower surfaces of each tension band, an upper concave portion and a lower concave portion as a plurality of engaged portions arranged in the belt length direction are respectively provided. It is provided corresponding to up and down. On the other hand, a pair of left and right fitting portions in the form of notches for fitting tension bands are formed on the belt width direction side portions of the respective blocks. An upper convex portion is provided, and a lower convex portion as a lower meshing portion is provided on the lower surface. Each block is engaged and fixed to both tension bands by press-fitting and fitting the tension bands to the left and right fitting portions of each block.

As shown in Japanese Patent Application Laid-Open No. 2000-120798, the lower part of the fitting part of each block is located at the lower corner of the inner part in the tension band press-fitting direction and the upper part is located at the lower part of the fitting part. A lower back abutment surface is formed to be inclined so as to face, and a lower back abutment surface angle α formed by the lower back abutment surface and the plane in the vertical direction, and a contact portion of the block on the left and right side surfaces with the pulley and the vertical The relationship with the belt side angle β formed by the plane is
When the lower back abutment surface is formed in the range from the position of the pitch line or from the position above the pitch line to the lower side, β-3 <α <β + 3, while the lower back abutment surface is the pitch line. When it is formed in a range from the lower position to the lower side, by setting α ≦ β, the angle of the lower back abutting part of the tension band end facing the inner part of the fitting part of the block and A proposal has been made in which the relationship between the angle of the lower and rear abutment surfaces of the block is made appropriate, the occurrence of uneven wear of the tension band is suppressed, the durability of the belt is increased, and noise is reduced.

[0004] In addition, each block of the belt, including the one in this proposal, is a composite of a reinforcing material and a resin portion, and the reinforcing material is made of a high-strength material such as a metal made of an aluminum alloy or a steel material. The resin portion is used to support a load applied to the block, while the resin portion is used to form a contact portion with the pulley of the block and a fitting portion with the tension band.

[0005]

However, in the case of the above proposed example, the lower back contact portion of the tension band to be fitted to the fitting portion of the block is formed in an inclined shape so that the tension band has a V-belt shape. By doing so, the uneven wear can be significantly reduced, but there is a problem that the block is damaged when the belt is run at a high speed, and there is room for further improvement.

That is, as described above, in the structure in which the load is supported by the reinforcing material of the block, a so-called edge portion (corner portion) is formed at the upper and lower end positions of the lower back contact surface of the fitting portion. Stress concentrates on this edge portion, and the reinforcing material is easily broken.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-load transmission V-belt block having a V-belt-shaped tension band, as described in the above proposed example, in which the fitting is performed. It is an object of the present invention to minimize the occurrence of block breakage when the belt runs at high speed by improving the structure of the section.

[0008]

In order to achieve the above object, according to the present invention, a belt block is composed of a reinforcing material and a resin portion, and a lower portion of a fitting portion deep portion for fitting a tension band thereof. When a lower back contact surface made of resin is formed at the corner, the resin thickness of at least the upper and lower ends of the lower back contact surface is set to a predetermined value or more.

More specifically, according to the first aspect of the invention, a number of upper meshed portions and lower meshed portions arranged in the belt length direction on the upper surface on the back side of the belt and the lower surface on the bottom surface respectively correspond to the upper and lower sides. An endless tension band provided and a fitting portion into which the tension band is press-fitted and fitted, and an upper meshing portion meshing with an upper meshed portion of the tension band on an upper surface of the fitting portion, Also, a lower meshing portion meshing with the lower meshed portion of the tension band is formed on the lower surface, and a number of blocks provided with contact portions in contact with the pulley groove surface on the side surface in the belt width direction are provided. By fitting the tension band to the fitting portion of the block, each block engages with the tension band such that both the contact portion of the block side surface on the side surface in the width direction of the belt and the tension band side surface contact the pulley groove surface. It is fixed by the meshing part of the block and the meshed part of the tension band. V-belt for high load transmission which the power transfer is performed by meshing of interest.

[0010] A lower back abutment surface that is inclined upward and toward the back of the fitting portion is formed at a lower corner of the back portion of the fitting portion of each block in the tension band press-fitting direction. It is formed in the range from the position above the line or from the position above the pitch line to the lower side (the upper end of the lower back abutting surface is located at or above the pitch line position of the belt). The lower rear contact surface angle α (unit °) between the contact surface and the vertical plane is equal to the belt side surface angle β (unit °) between the contact portions on the left and right side surfaces of the block and the vertical surface. , Β−3 <α <β + 3.

Each block is composed of at least a resin portion forming the contact portion and the fitting portion, and a reinforcing material made of a material having a higher elastic modulus than the resin portion. The thickness of the resin portion on the reinforcing material at least at the upper and lower end positions of the back abutment surface is 0.3 mm or more.

With the above arrangement, the contact surface angle α of the lower contact surface of the contact surfaces of the belts at the fitting portion of each block is within the range of α = β ± 3 with respect to the belt side surface angle β. Therefore, the relationship between the angle of the lower back abutment portion of the tension band and the angle of the lower back abutment surface of the block becomes appropriate, and the moment force acting on the tension band in the fitting portion of the block is reduced. You. As a result, uneven wear of the tension band is suppressed,
The fatigue rate of the core wire is reduced, and the durability of the belt until the core wire is cut can be improved.

Further, the fact that the moment force of the tension band in the block becomes small means that the force generated on the contact surface between the block and the tension band is also made uniform.
Heat generation during running of the belt can be reduced. That is, as the heat generation factor of the belt, there are heat generated by bending, compression, and shear deformation of rubber when the belt is repeatedly wound around the pulley, and heat generated by friction with the pulley groove surface.
When the tension band is unevenly worn, the tension band is moved in the width direction, and frictional heat is generated on the engagement surface of the tension band with the block, which also causes belt heat generation. But,
In the belt that does not cause uneven wear as in the present invention, the frictional heat generated at the engagement surface between the tension band and the block is reduced.

Further, since the thickness of the resin portion on the reinforcing material at least at the upper and lower end positions of the lower back contact surface of the fitting portion of each block is 0.3 mm or more, the upper and lower portions of the lower back contact surface can be adjusted. Even when the thickness of the resin at the end position becomes large and the belt moves at high speed, even if the upper and lower end positions of the lower back abutting surface are edge portions and stress concentration occurs, the stress acting on the reinforcing material from the edge portion Can be alleviated, and the breakage of each block can be suppressed to extend the life of the belt.

The thickness of the resin part on the reinforcing material at the upper and lower end positions of the lower back contact surface of the fitting portion of the block is 0.3 m.
If it is less than m, the effect of relaxing the stress acting on the reinforcing material cannot be obtained, so it is set to 0.3 mm or more.

If the lower rear contact surface angle α is equal to or smaller than β-3 or larger than β + 3, the lower rear contact surface angle α and the belt side surface angle β Is too large, the heat generation during running of the belt increases, and uneven wear occurs. Therefore, α is set in the range of α = β ± 3.

According to a second aspect of the present invention, in the high load transmission V-belt similar to the first aspect of the invention, the similar lower back abutment surface is shifted from a position below the belt pitch line to a position below the belt pitch line. (The upper end of the lower rear abutment surface is located below the pitch line of the belt), and the lower rear abutment formed by the lower rear abutment surface and the plane in the vertical direction. The surface angle α (unit degrees) is set to α ≦ β with respect to the belt side surface angle β (unit degrees) formed between the contact portions on the left and right side surfaces of the block and the plane in the vertical direction. Each block is composed of at least a resin part forming the contact part and the fitting part, and a reinforcing material made of a material having a higher elastic modulus than the resin part. The thickness of the resin portion on the reinforcing material at least at the upper and lower ends of the surface is 0.3 mm or more.

That is, if the lower back contact surface angle α of the lower back contact surface of the block fitting back portion is greater than or equal to the belt side surface angle β, the force cannot be balanced, and the invention of claim 1 A similar effect cannot be obtained effectively. In other words, when the lower back contact surface of the fitting portion is formed from a position below the belt pitch line position, a downward force is applied to the meshing portion of the block from the cord of the tension band, but the tension is In order to prevent the moment force from acting on the band, since the lower back abutment surface is below the position of the core line, the lower back abutment surface angle α (wedge angle) must be further reduced to reduce the force. Can not be balanced. Therefore, the relationship between the belt side surface angle β and the lower back abutment surface angle α is 0 <α ≦ β, and the lower back abutment surface angle α is the same as or slightly smaller than the belt side surface angle β and has an optimum balance. Becomes In this case, the same operation and effect as the first aspect of the invention can be obtained.

Further, since the thickness of the resin portion on the reinforcing material at least at the upper and lower end positions of the lower back abutting surface of the fitting portion of each block is 0.3 mm or more, the upper and lower portions of the lower back abutting surface can be moved upward and downward. Resin thickness at the end position can be increased, and even if stress concentration occurs when the upper and lower end positions of the lower back abutment surface become edges during high-speed running of the belt, stress acting on the reinforcing material from that edge is reduced. It is possible to suppress breakage of each block and extend the life of the belt.

According to the third aspect of the present invention, the first or second aspect is provided.
In the high load transmission V-belt, the thickness of the resin portion on the reinforcing material at least at the upper and lower end positions of the lower back contact surface of the fitting portion of the block is 0.4 mm or more. As a result, a desired value of the thickness of the resin on the reinforcing material at the upper and lower end positions of the lower back contact surface of the fitting portion is obtained, and the lower back contact at the fitting portion of each block during high-speed running of the belt. The stress acting on the reinforcing material from the upper and lower end positions (edge portions) of the surface can be further effectively reduced, and the breakage of each block can be suppressed to further extend the life of the belt.

According to the fourth aspect of the invention, similar to the first aspect,
A lower back contact surface is formed in the fitting portion of the block in the high load transmission V-belt in a range from the position of the pitch line or from the position above the pitch line to the lower side, and the lower back contact surface and the vertical The lower rear abutment surface angle α (unit: °) between the plane and the plane is β−the belt side surface angle β (unit degree) between the contact portions on the left and right side surfaces of the block and the above-described vertical plane.
3 <α <β + 3, and each block includes at least a resin portion forming the contact portion and the fitting portion, and a reinforcing material made of a material having a higher elastic modulus than the resin portion.

At the upper end of the lower rear contact surface of the fitting portion of the block, an upper step portion inclined at an angle smaller than the lower rear contact surface with respect to the vertical plane is provided. At the lower end of the surface, there is provided a lower step portion that is inclined at an angle larger than the lower rear abutment surface with respect to the vertical plane.

Thus, the thickness of the resin portion on the reinforcing material at the upper and lower end positions of the lower back contact surface of the fitting portion of each block can be kept large by the step portion. Moreover, stress concentration at the upper and lower end positions of the lower back contact surface can be reduced by the step portion, and breakage of each block during high-speed running of the belt can be suppressed, thereby extending the life of the belt.

According to the fifth aspect of the present invention, similar to the second aspect,
A lower back abutment surface is formed in the block fitting portion of the high load transmission V-belt in a range from a lower position to a lower side than the pitch line, and is formed between the lower back abutment surface and a vertical plane. The lower rear abutment surface angle α (unit °) is α ≦ β with respect to the belt side surface angle β (unit °) between the contact portions on the left and right side surfaces of the block and the vertical plane, and each block has at least It is composed of a resin part forming the contact part and the fitting part, and a reinforcing material made of a material having a higher elastic modulus than the resin part.

At the upper end of the lower rear contact surface of the fitting portion of the block, an upper step portion inclined at a smaller angle than the lower rear contact surface with respect to the vertical plane is provided. At the lower end of the surface, there is provided a lower step portion that is inclined at an angle larger than the lower rear abutment surface with respect to the vertical plane. According to this invention, the same operation and effect as those of the fourth aspect can be obtained.

According to the sixth aspect of the invention, similar to the first aspect,
A lower back contact surface is formed in the fitting portion of the block in the high load transmission V-belt in a range from the position of the pitch line or from the position above the pitch line to the lower side, and the lower back contact surface and the vertical The lower rear abutment surface angle α (unit: °) between the plane and the plane is β−the belt side surface angle β (unit degree) between the contact portions on the left and right side surfaces of the block and the above-described vertical plane.
3 <α <β + 3, and each block includes at least a resin portion forming the contact portion and the fitting portion, and a reinforcing material made of a material having a higher elastic modulus than the resin portion.

At the upper and lower ends of the lower abutment surface of the fitting portion of the block, arcuate portions bulging toward the back of the fitting portion are provided.

With this configuration, the thickness of the resin portion on the reinforcing material at the upper and lower end positions of the lower back abutting surface of the fitting portion of each block can be kept large by the arc portion, and the lower back protrusion can be maintained. Stress concentration at the upper and lower end positions of the contact surface can be alleviated by the arc portion, so that breakage of each block during high-speed running of the belt can be suppressed, and the life of the belt can be extended.

According to the seventh aspect of the invention, similar to the second aspect,
A lower back abutment surface is formed in the block fitting portion of the high load transmission V-belt in a range from a lower position to a lower side than the pitch line, and is formed between the lower back abutment surface and a vertical plane. The lower rear abutment surface angle α (unit °) is α ≦ β with respect to the belt side surface angle β (unit °) between the contact portions on the left and right side surfaces of the block and the vertical plane, and each block has at least It is composed of a resin part forming the contact part and the fitting part, and a reinforcing material made of a material having a higher elastic modulus than the resin part.

And, at the upper and lower ends of the lower rear abutting surface of the fitting portion of the block, arcuate portions bulging to the far side of the fitting portion are provided. According to this invention, the same operation and effect as those of the sixth aspect can be obtained.

[0031]

(Embodiment 1) FIG. 3 shows a high-load transmission V-belt B according to Embodiment 1 of the present invention. The belt B has a pair of left and right endless tension bands 1, 1. , Which are continuously engaged and fixed to the tension bands 1, 1 in the longitudinal direction of the belt. As shown in FIG. 4, each tension band 1 has a shape-retaining layer 1a made of hard rubber.
A plurality of high-strength and high-modulus core wires 1b, 1b,... (Core body) such as aramid fibers are spirally arranged and buried inside. 7 as grooved upper concave portions 2, 2,... As upper meshed portions having a constant pitch extending in the belt width direction, and on the lower surface, corresponding to the upper concave portions 2, 2,. The lower concave portion 3 as a lower engaged portion of a constant pitch extending to
Are formed respectively. Further, canvases 4 and 4 are adhered to the upper and lower surfaces of the tension band 1 for the purpose of improving the wear resistance and the like.

The hard rubber that forms the shape-retaining layer 1a is made of, for example, H-NBR rubber reinforced with zinc methacrylate and further reinforced with short fibers such as aramid fiber and nylon fiber, so that it has excellent heat resistance and permanent properties. Hard rubber that is hard to deform is used. The hardness of the hard rubber requires a rubber hardness of 75 ° or more as measured by a JIS-C hardness tester.

On the other hand, as shown in FIG.
Has notched groove-shaped fitting portions 8, 8 on which the tension bands 1 are detachably fitted in the width direction on the left and right sides in the belt width direction. The left and right side surfaces excluding the fitting portion 8 are configured as contact portions 11, 11 that come into contact with a pulley groove surface (not shown) of the V pulley, and a belt angle formed by the left and right contact portions 11, 11 of the block 7. Is the same as the angle of the pulley groove surface. The block 7 has a substantially H-shape including upper and lower beams 7a and 7b extending in the belt width direction (left and right direction) and pillars 7c connecting the left and right central portions of the two beams 7a and 7b up and down. Are press-fitted into fitting portions 8, 8 of each block 7, respectively, so that the blocks 7, 7,... It is fixed continuously in the direction.

That is, on the upper wall surface of each fitting portion 8 in each block 7, an upper convex portion 9 formed of a ridge as an upper meshing portion meshing with each upper concave portion 2 on the upper surface of the tension band 1.
However, on the lower wall surface of the fitting portion 8, lower convex portions 10 are formed in parallel with each other, and are formed of convex streaks as lower meshing portions meshing with the lower concave portions 3 on the lower surface of the tension band 1. By engaging the upper and lower convex portions 9 and 10 of each block 7 with the upper and lower concave portions 2 and 3 of the tension band 1, respectively, the blocks 7, 7,. In this engaged state, both the outer side surface of each tension band 1 and the contact portion 11 which is the side surface of each block 7 come into contact with the pulley groove surface, and the upper and lower convex portions 9 , 10 (meshing portion) and upper and lower recesses 2, 3 of each tension band 1
The power transmission and reception is performed by meshing with the (meshed portion).

Each of the blocks 7 is formed by embedding a reinforcing material 12 such as a lightweight aluminum alloy, which is a material having a higher elastic modulus, in a hard resin so as to be located substantially at the center of the block 7. Thus, the block 7 is constituted by the hard resin portion forming the peripheral portion of the fitting portion 8 and the contact portions 11, and the reinforcing material 12 forming the remaining portion. The reinforcing member 12 includes an upper boom portion 12a located above the fitting portion 8 of the block 7 and a lower end edge extending substantially horizontally, and an upper boom portion located below the fitting portion 8 and having an upper end edge formed on the upper beam. Part 12a
Lower beam portion 12b extending substantially horizontally in parallel with the lower edge of the lower beam
The upper and lower beam portions 12a and 12b are formed in a substantially H-shape comprising a pillar portion 12c connecting the left and right central portions of the upper and lower beam portions vertically and having left and right end edges extending substantially vertically. Between the lower edge and the left and right edges of the pillar portion 12c, and between the upper edge of the lower beam portion 12b and the pillar portion 12;
The left and right end portions c are connected to each other by upper and lower arc surfaces 12d and 12e that protrude in an arc shape on the inner side of the fitting portion 8, respectively. It is sufficient that the reinforcing material 12 does not appear on the surface of the block 7 at the peripheral portion of the fitting portion 8 and the contact portions 11 and 11 (sliding contact portions with the pulley groove surface) on the left and right side surfaces. May be exposed on the surface of the block 7.

Further, as shown in FIG. 1, each of the right and left fitting portions 8, 8 of each of the blocks 7 is fitted upwardly into a lower corner of the deep portion in the tension band press-fitting direction. A lower back abutment surface 16 is formed to be inclined toward the back (the center side in the belt width direction) of the joint 8.
Is cut off from a position above the position of the pitch line Lp of the belt B (the position of the core wire 1b of the tension band 1) (the upper end of the lower back abutting surface 16 is above the position of the pitch line Lp of the belt). Located).

The lower rear contact surface angle α between the lower rear contact surface 16 and the plane P in the vertical direction (a plane parallel to the plane passing through the center in the width direction of the belt B) is defined by the left and right side surfaces of the belt B. That is, the belt side angle β between the left and right contact portions 11 of each block 7 and the plane P is β-3 <α <β +
It is set to 3.

If the lower rear abutment surface angle α of the lower rear abutment surface 16 is α ≦ β−3 or α ≧ β + 3 with respect to the belt side surface angle β, the lower rear abutment surface angle α The difference from the belt side angle β is too large. When the difference increases, the heat generated by the belt B during traveling increases, and uneven wear of the tension band 1 occurs. Therefore, β−3 <α <β + 3 is set. In particular, it is desirable that α = β.

The end of the tension band 1 in the width direction of the belt is located below the inner end of the block 7 facing the depth of the fitting portion 8, and at the depth of the fitting portion 8 upward. A lower back abutment portion 5 that is inclined so as to face is formed. The lower back abutment angle α ′ formed between the lower back abutment portion 5 and the vertical plane P is α−1 ≦ α ′ ≦ α + 3 with respect to the lower back abutment surface angle α on the block 7 side. ing.

The relationship between the lower rear abutment angle α ′ and the lower rear abutment surface angle α of the lower rear abutment portion 5 of the tension band 1 is α ′> α +
3, the lower rear contact angle α ′ becomes too large, and the lower rear contact portion 5 of the tension band 1 does not contact the lower rear contact surface 16 of the block 7. The lower surface of the block 7 is pressed by the lower surface to form a depression, and a force imbalance is generated from the depression as a starting point, the balance between the right and left forces is lost, and heat generation of the belt B and uneven wear occur. On the other hand, if α ′ <α−1, the lower back contact angle α ′
Is too small, and when the tension band 1 is pressed into the fitting portion 8 of the block 7, the tension band 1
The upper and lower beam portions 12a, 12b are pushed up and down in a crotch-up state, and excessive stress is generated at the roots of the upper and lower beam portions 12a, 12b, so that the reinforcing member 12 is easily damaged. Therefore, the lower rear contact angle α ′ of the lower rear contact portion 5 of the tension band 1 is in the range of α−1 ≦ α ′ ≦ α + 3.

Further, an upper back abutment which is inclined downward toward the back side of the fitting portion 8 at the upper corner portion of the fitting portion 8 of each block 7 in the tension band press-fitting direction. Face 1
7 are provided.

The engagement thickness Tt between the upper and lower concave portions 2 and 3 of the tension band 1 made of the hard rubber, that is, the bottom surface of the upper concave portion 2 (specifically, the upper surface of the upper canvas 4) as shown in FIG.
The distance between the lower recess 3 corresponding to the upper recess 2 and the bottom surface of the lower recess 3 (the lower surface of the lower canvas 4) is equal to the mesh gap Tb of the block 7, that is, the upper side of each block 7 as shown in FIG. The distance between the lower end of the convex portion 9 and the upper end of the lower convex portion 10 is slightly larger by, for example, about 0.03 to 0.15 mm (Tt> T).
b) It is set, and when the blocks 7 are assembled to the tension band 1, the tension band 1 is compressed and assembled in the thickness direction by the block 7, thereby providing the interference Tt-Tb (> 0). Have been.

Also, as shown in FIG. 1, on both left and right sides of the belt B, the outer end surface of the tension band 1 is slightly (for example, 0.03 to 0.03 to 1) from the surfaces of the contact portions 11 made of resin of each block 7. 0.15 mm), so that a protrusion Δd is provided. The protrusion Δd is determined by changing the pitch width of the tension band 1 (width at the core wires 1b, 1b,...) By the insertion pitch width of the fitting portion 8 (the tension band fitted to the fitting portion 8). (The groove depth at the position of one core wire 1b) can be freely changed. Each tension band 1 is press-fitted into the fitting portion 8 of each block 7 and inserted. To complete the press-fitting, the belt B should be tensioned with a force greater than the force received from the pulley groove surface during actual use. 1 must be pressed. This margin Δd can be easily measured by scanning the left and right side surfaces of the belt B after assembly with a contracer (contour shape measuring device).

Then, as shown in FIG. 1, the upper end position A of the upper rear contact surface 17 in the fitting portion 8 of each block 7
The upper end position B (the connection part with the upper back contact surface 17) of the lower back contact surface 16 (the connection portion with the upper protrusion portion 9) and the upper end position B of the lower back contact surface 16 are
The lower end position C of the lower back abutting surface 16 (the connection portion with the lower convex portion 10) is arranged corresponding to the lower arc surface 12e of the reinforcing member 12, respectively. Are also formed at the edge portions (corner portions), and this edge structure allows the resin thicknesses a to c on the reinforcing material 12 at the positions A to C to be formed.
Is smaller than the other parts,
m (the resin thicknesses a to c are 0.4 to 0.4 m).
mm or more is preferable).

Therefore, in this embodiment, the lower rear contact surface angle α of the lower rear contact surface 16 in each fitting portion 8 of each block 7 of the belt B is smaller than the belt side angle β of the belt B by α = Β ± 3, the angle of the lower back abutment portion 5 of the tension band 1 and the lower back abutment surface 16 of the block 7
And the moment force acting on the tension band 1 in the fitting portion 8 of the block 7 is reduced. For this reason, uneven wear of the tension band 1 is suppressed, the fatigue rate of the core wire 1b is reduced, and the belt B until the core wire 1b is cut off.
Durability can be increased.

Further, since the moment force of the tension band 1 in the block 7 becomes small, the tension band 1
The force generated on the contact surface with the belt B can also be made uniform, and the heat generated during running of the belt B can be reduced. That is, this belt B
As one of the heat generating factors, the tension band 1 causes uneven wear,
The movement of the tension band 1 in the width direction occurs, and the block 7 of the tension band 1 is moved.
In the belt B which does not cause uneven wear of the tension band 1 as described above, frictional heat generation at the meshing surface between the tension band 1 and the block 7 is reduced. .

Further, in this embodiment, the angle of the lower back contact portion 5 of the tension band 1 and the lower back contact surface 16 of the block 7 are set.
And the uneven wear of the tension band 1 is suppressed, so that the temporal change between the protrusion Δd and the interference Tt−Tb becomes small, and the low noise of the belt B is reduced over a long period of time. The belt B can be maintained, and the durability of the belt B can be increased as compared with the case where there is no interference Tt-Tb or a protrusion Δd. That is, the initial belt noise is reduced by providing the allowance Δd, and the loosening of the engagement between the tension band 1 and the block 7 is suppressed by providing the interference Tt-Tb. By optimizing the back abutment shape, uneven wear of the tension band 1 is eliminated, and the interference Tt-Tb
Is maintained for a long period of time, and the decrease in the engagement thickness Tt of the tension band 1 due to uneven wear is also delayed.

Further, according to the back butting structure of this embodiment, even if the protrusion Δd and the interference Tt-Tb are considerably increased, the heat generation of the belt B can be suppressed, and the noise of the belt B can be reduced. be able to. Further, unlike the related art, it is not necessary to strictly make the dimensional accuracy of the meshing portion between the tension band 1 and the block 7, and the tolerance of the interference Tt−Tb and the protrusion Δd can be increased.

Further, since the upper abutment surface 17 is provided on the upper side of the innermost portion of the fitting portion 8 of each block 7 in the tension band press-fitting direction, stress concentration on the block 7 is prevented, and the belt B Life can be extended.

Further, the upper end position A of the upper back abutting surface 17 in the fitting portion 8 of each block 7 and the lower back abutting surface 1
6, the upper and lower end positions B and C are both edge portions, and the resin thickness a to c on the reinforcing material 12 at each of the positions A to C
Are kept large at 0.3 mm or more, even if stress concentrates at the edges A to C at the time of high-speed running of the belt B, it acts on the reinforcing material 12 from the edges. This can alleviate the stress of the belt B, thereby suppressing the breakage of each block 7 and extending the life of the belt B.

(Embodiment 2) FIGS. 5 and 6 show Embodiment 2 of the present invention (in the following embodiments, the same parts as in FIGS. In the first embodiment, the resin thicknesses of the upper end position A of the upper back contact surface 17 and the upper and lower end positions B and C of the lower back contact surface 16 in the fitting portion 8 of each block 7 are described. While a to c are set to be large, step portions for stress relaxation are provided at upper and lower end positions B and C of the lower back contact surface 16.

That is, in this embodiment, the upper end (the boundary with the upper rear abutment surface 17) of the lower rear abutment surface 16 in the fitting portion 8 of each block 7 is placed lower than the vertical plane P. Angle α1 smaller than the inclination angle α of the rear abutment surface 16
An upper step 18 inclined at (<α) is provided.
On the other hand, the lower end portion of the lower rear contact surface 16 (the boundary between the lower rear contact surface 16 and the lower convex portion 10) has an inclination angle α of the lower rear contact surface 16 with respect to the vertical plane P. Also large angle α2
A lower step portion 19 inclined at (> α) is provided, and the lower step portion 19 is formed over a range between the upper end top and the lower end base of the lower projection 10 on the lower surface of the fitting portion 8. ing. That is, the upper end of the lower step portion 19 corresponds to the top of the upper end of the lower protrusion 10, and the lower end corresponds to the lower end base of the lower protrusion 10. Other configurations are the same as those in the first embodiment.

Therefore, in the case of this embodiment, the step portions 18 and 19 are formed at the upper and lower end positions of the lower back contact surface 16 in the fitting portion 8 of each block 7, respectively.
The step portions 18 and 19 can maintain a large resin thickness on the reinforcing material 12 at the upper and lower end positions of the lower back contact surface 16 and reduce the stress concentration on the upper and lower end positions of the lower back contact surface 17. This can be alleviated by the portions 18 and 19, and therefore, the same operation and effect as in the first embodiment can be obtained.

In the second embodiment, the lower step 19
Is formed in a range between the upper end top and the lower end base of the lower convex portion 10 on the lower surface of the fitting portion 8, as shown in FIG. 7, the lower step portion 19 is formed as a lower convex portion. 10 may be formed in a range between a position above the top of the upper end of the lower part 10 and the base of the lower end (the upper end of the lower step part 19 is arranged at a position above the upper end of the lower protrusion 10). The same functions and effects as those of the second embodiment can be obtained.

(Embodiment 3) FIGS. 8 and 9 show Embodiment 3.
In the second embodiment, the fitting portion 8 of each block 7 is used.
Steps 18, 1 at the upper and lower ends of the lower back contact surface 16
9 is formed, but an arc portion is formed.

That is, in this embodiment, the upper arcuate portion 20 swelling toward the back side of the fitting portion 8 is provided at the upper end of the lower back contact surface 16 in the fitting portion 8 of each block 7. At the lower end of the abutment surface 16, there are provided lower arc portions 21, which similarly protrude to the inner side of the fitting portion 8, and the lower arc portions 21 are lower projection portions on the lower surface of the fitting portion 8. 10 is formed over a range between a position above the upper end top and a lower end base (the upper end of the lower circular arc portion 21 is at a position above the upper end top of the lower convex portion 10, and the lower end is Corresponding to the lower end bases of the lower protrusions 10). Other configurations are the same as those of the second embodiment.

In this embodiment, since the arc portions 20 and 21 are formed at the upper and lower end positions of the lower back contact surface 16 in the fitting portion 8 of each block 7, respectively, the arc portions 20 and 21 define The same operation and effect as in the second embodiment can be obtained.

(Embodiment 4) FIGS. 10 and 11 show Embodiment 4. In each of the above-described embodiments, the upper concave portion 2 as the engaged portion is provided on the upper surface of the tension band 1 and the fitting portion of each block 7 is provided. On the upper surface of the tension band 1, an upper convex portion 9 as a meshing portion that meshes with the upper concave portion 2 of the tension band 1 is formed. An upper concave portion 24 is provided on the upper surface of the fitting portion 8 of each block 7 as a meshing portion that meshes with the upper convex portion 23 on the upper surface of the tension band 1.

Then, the engagement thickness Tt of the tension band 1, that is, the top surface of the upper convex portion 23 (the upper canvas 4) as shown in FIG.
The distance between the upper surface of the block 7 and the bottom surface of the lower concave portion 3 (the lower surface of the lower canvas 4) corresponding to the upper convex portion 23 is smaller than that of the block 7.
10, that is, slightly larger than the distance between the bottom surface of the upper concave portion 24 of each block 7 and the upper end of the lower convex portion 10 (Tt> Tb) as shown in FIG. When the tension band 1 is assembled to the tension band 1, the tension band 1 is compressed in the thickness direction by the block 7 and assembled, and the interference T
t-Tb is provided. Other configurations are the same as those of the first embodiment. Therefore, in this embodiment, the same operation and effect as in the first embodiment can be obtained.

(Fifth Embodiment) FIG. 12 shows a fifth embodiment of the present invention, in which the lower back contact surface 16 of each fitting portion 8 of each block 7 is cut away from the position of the pitch line Lp of the belt B. (The upper end of the lower rear abutment surface 16 is at the same position as the pitch line Lp of the belt B). Other configurations are the same as those of the above-described first embodiment, and this embodiment can also provide the same operation and effects as those of the first embodiment.

(Sixth Embodiment) FIG. 13 shows a sixth embodiment. In this embodiment, the lower back contact surface 16 in each fitting portion 8 of each block 7 is cut out from a position below the position of the pitch line Lp of the belt B (the lower back contact surface 16). Is at a position below the pitch line Lp of the belt B).

The angle α (unit: °) between the lower rear abutment surface 16 and the vertical plane P in each fitting portion 8 of each block 7 is equal to the left and right side surfaces of the belt B. With respect to the belt side surface angle β (unit degrees) formed with the plane P,
0 <α ≦ β.

That is, when the lower rear abutment surface 16 of the fitting portion 8 is formed from a position below the pitch line Lp of the belt B, the center line 1b of the tension band 1
A downward force is applied to the meshing portion of the lower surface, but in order to prevent the moment force from acting on the tension band 1, the lower rear contact surface 16 is required.
Is located below the position of the core wire 1b, the force cannot be balanced unless the wedge angle α of the lower rear abutment surface 16 is further reduced. If the lower rear abutment surface angle α of the lower rear abutment surface 16 at the deep portion of the fitting portion 8 of the block 7 is equal to or greater than the belt side surface angle β, the balance of the forces cannot be obtained, and the effect cannot be obtained effectively. Therefore, the relationship between the belt side surface angle β and the lower back abutment surface angle α is 0 <α ≦ β, and the lower back abutment surface angle α is an optimum balance at an angle slightly smaller than the belt side surface angle β. And if β-6 <α, then
The lower back contact surface 16 of the fitting portion 8 is the belt B pitch line L
In a structure formed from a position lower than p, a more desirable relationship between the lower back contact surface angle α and the belt side surface angle β is obtained. Others are the first embodiment.
In this embodiment, the same operation and effect as in the first embodiment can be obtained.

It should be noted that, in addition to the structure of the fourth embodiment, the present invention has a lower convex portion as a meshing portion on the lower surface of the tension band 1 and a tension band on the lower surface of the fitting portion 8 of each block 7. A lower concave portion may be provided as a meshing portion that meshes with the lower convex portion of the lower surface. In short, a number of upper meshed portions and lower meshed portions arranged in the belt length direction are provided on the upper and lower surfaces of the tension band 1 corresponding to the upper and lower sides, respectively, while the tension band 1 is press-fitted into each block 7. A fitting portion to be fitted is provided, an upper meshing portion meshing with the upper meshing portion of the tension band 1 is provided on an upper surface of the fitting portion, and a lower meshing portion is meshing with a lower meshing portion of the tension band 1 on the lower surface. The meshing portions may be formed, and the block 7 and the tension band 1 may be integrated by meshing the meshing portion and the meshed portion.

[0065]

Next, a specific embodiment will be described. Basically, as a high load transmission V-belt, the belt angle is 26 ° (therefore, the belt side angle β = 13 °), the width of the block 7 at the belt line is 25 mm,
A block belt having the same structure as that of Embodiment 1 (see FIG. 1) having a pitch interval in the belt length direction of 3 mm, a thickness of the block 7 of 2.95 mm, and a belt length of 612 mm was produced. Each block 7 is made of an H-shaped reinforcing material 1 made of a lightweight high-strength aluminum alloy having a thickness of 2 mm.
2 is insert-molded in phenolic resin, and the lower back contact surface 16 of the fitting portion 8 is formed from a position above the position of the pitch line Lp (the position of the tension band core wire).

In the block belt B having this structure, the reinforcing material 12 at the upper end position B of the fitting portion 8 of each block 7 at the upper end position B (the connection portion with the upper back abutting surface 17).
The upper resin thickness b and the resin thickness c on the reinforcing material 12 at the lower end position C of the lower back abutting surface 16 (connection portion with the lower convex portion 10)
And both values b and c are both 0.3 m
m and at least one of the values b and c are equal to or less than 0.1.
Comparative Examples 1 to 3 mm, the other being 0.3 mm or more
Four belts of each type were made.

The belt B of each example was subjected to an endurance running test, and the time until breakage was measured. The durability running test conditions of the belt B are as follows. That is, as shown in FIG.
The belt B of each example is wound around a 0 mm driven pulley 28, and the driving pulley 27 is
The durability when rotating at a driving torque of 3 N · m and a high rotation speed of 6500 rpm was evaluated. The results obtained are shown in Table 1 below.

[0068]

[Table 1]

According to the results shown in Table 1, Example 1
In any of Nos. To 4, no breakage of the belt occurred until 500 hours.

On the other hand, in Comparative Examples 1 and 2, the block 7 was damaged at the upper end position B of the lower back abutting surface 16 having a resin thickness of less than 0.3 mm before 500 hours passed. Similarly, in blocks 3 and 4, early breakage of the block 7 occurred at the lower end position C of the lower back abutting surface 16 having a resin thickness of less than 0.3 mm.

As is clear from the examples and the comparative examples, the lower back contact surface 16 in the fitting portion 8 of the block 7 is formed.
Both the resin thicknesses b and c at the upper and lower end positions B and C are set to 0.
It can be seen that by setting the length to 3 mm or more, it is possible to prevent block damage during high-speed running of the belt B, and to extend the life of the belt B.

[0072]

As described above, according to the first aspect of the present invention, the endless tension band having the upper and lower meshed portions provided on the upper and lower surfaces, respectively, and the fitting portion into which the tension band is fitted. An upper meshing portion is formed on an upper surface, and a lower meshing portion is formed on a lower surface. Each of the blocks has a plurality of blocks provided with contact portions in contact with a pulley groove surface on a side surface in a belt width direction. The high tension transmission V-belt is engaged and fixed so that both the block side and the tension band side come into contact with the pulley groove surface with respect to the tension band. On the other hand, a lower back abutment surface is formed at the pitch line position or a position above the pitch line at the back of the fitting portion of each block, and a lower back abutment formed by the lower back abutment surface and a plane in the vertical direction. The contact surface angle α is the same as the contact area on the left and right Β-3 <α <β + 3 with respect to the belt side surface angle β formed by the surface, and at least a contact portion of each block to the pulley groove surface and a fitting portion are made of resin, while the remaining portion is made of a material having a higher elastic modulus than resin. The thickness of the resin on the reinforcing material at least at the upper and lower end positions of the lower back contact surface of the fitting portion of the block was 0.3 mm or more. In the invention of claim 2, the same high load transmission V
For the belt, a lower back abutment surface is formed at the back of the fitting portion of each block from a position below the pitch line position, and the lower back abutment surface angle α formed by the lower back abutment surface is set to the belt. Α ≦ β with respect to the side surface angle β, and the thickness of the resin on the reinforcing material at least at the upper and lower end positions of the lower back contact surface of the fitting portion of each block is 0.3 mm or more. Therefore, according to these inventions, the relationship between the angle of the lower back abutment portion of the tension band and the angle of the lower back abutment surface of the block is made appropriate, and the moment force acting on the tension band in the fitting portion of the block is reduced. In addition to suppressing uneven wear of the tension band, slowing the fatigue rate of the core wire, the force generated at the contact surface between the block and the tension band is also uniformed, reducing the heat generated during belt running, and consequently high load transmission. For V
The durability of the belt can be improved. In addition, by increasing the thickness of the resin at the upper and lower end positions of the lower back contact surface of the fitting portion of each block, the upper and lower end positions of the lower back contact surface become edges when the belt is running at a high speed, and the stress is increased. Even if concentration occurs,
The stress acting on the reinforcing material from the edge portion can be reduced, and the breakage of each block can be suppressed to extend the life of the belt.

According to the third aspect of the present invention, the thickness of the resin on the reinforcing material at least at the upper and lower end positions of the lower back contact surface of the fitting portion of the block is set to 0.4 mm or more.
Desired value of the thickness of the resin on the reinforcing material at the upper and lower end positions of the lower back contact surface of the fitting portion is obtained, and furthermore, the breakage of each block at the time of high-speed running of the belt is suppressed to further improve the belt. The service life can be extended.

According to a fourth aspect of the present invention, in the high load transmission V-belt similar to the first aspect of the present invention, the upper end of the lower back contact surface of the fitting portion of the block is provided with a lower surface with respect to a vertical plane. An upper step portion that is inclined at an angle smaller than the rear abutment surface is provided, while a lower step portion that is inclined at an angle larger than the lower rear abutment surface with respect to the vertical plane at the lower end of the lower rear abutment surface. Was provided. According to a fifth aspect of the present invention, in the high-load transmission V-belt similar to the second aspect of the invention, an upper step portion similar to the above is provided on an upper end portion of a lower rear contact surface of a fitting portion of the block. In addition, similar lower steps were provided at the lower ends. According to these inventions, the thickness of the resin on the reinforcing material at the upper and lower end positions of the lower back contact surface of the fitting portion of each block can be kept large by the step portion, and
The same effect as that of the invention can be obtained.

According to a sixth aspect of the present invention, in the high-load transmission V-belt similar to the first aspect of the invention, the upper and lower ends of the lower-side abutment surface of the fitting portion of the block are provided on the inner side of the fitting portion. And a bulging arc portion is provided. According to the seventh aspect of the present invention, in the same high load transmission V-belt as the second aspect of the present invention, the same arc portions as those described above are provided at the upper and lower ends of the lower back contact surface of the fitting portion of the block. Was. According to these inventions, the thickness of the resin on the reinforcing material at the upper and lower end positions of the lower back contact surface of the fitting portion of each block can be kept large by the arc portion, and the invention according to claim 1 or 2 Similar effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG.

FIG. 2 is an enlarged side view of a block.

FIG. 3 is a perspective view showing a high-load transmission V-belt according to Embodiment 1 of the present invention.

FIG. 4 is an enlarged side view of a tension band.

FIG. 5 is a diagram corresponding to FIG. 1 showing a block of a high-load transmission V-belt according to a second embodiment.

FIG. 6 is a perspective view showing a fitting portion of the block.

FIG. 7 is a diagram corresponding to FIG. 6, showing a modification of the fitting portion of the block.

FIG. 8 is a view corresponding to FIG. 1 showing a block of a high-load transmission V-belt according to a third embodiment.

FIG. 9 is a diagram corresponding to FIG. 6, showing a fitting portion of the block.

FIG. 10 is a diagram corresponding to FIG. 2 showing a block of a high-load transmission V-belt according to a fourth embodiment.

FIG. 11 is a diagram corresponding to FIG. 4, showing a tension band of a high-load transmission V-belt according to a fourth embodiment.

FIG. 12 is a view corresponding to FIG. 1 showing a block of a high-load transmission V-belt according to a fifth embodiment.

FIG. 13 is a view corresponding to FIG. 1 showing a block of a high-load transmission V-belt according to a sixth embodiment.

FIG. 14 is a schematic view of a belt durability test apparatus.

[Explanation of symbols]

 B High-load transmission V-belt 1 Tension band 2 Upper concave portion (upper meshed portion) 3 Lower concave portion (lower meshed portion) 5 Lower rear abutment portion 7 Block 8 Fitting portion 9 Upper convex portion (upper mesh portion) 10) Lower convex portion (lower meshing portion) 11 Contact portion 12 Reinforcement material 16 Lower rear abutting surface 17 Upper rear abutting surface 18 Upper stepped portion 19 Lower stepped portion 20 Upper arc portion 21 Lower arc portion 23 Upper side Convex part (upper mesh part) 24 Upper concave part (upper mesh part) α Lower back abutment surface angle β Belt side angle a to c Resin thickness Tt Mesh thickness Tb Mesh gap Tt-Tb Tightening allowance Δd Outgoing Lp Pitch Line P Vertical plane

Claims (7)

[Claims] 1. An endless tension band in which a number of upper meshed portions and lower meshed portions arranged in the belt length direction are provided on the upper surface on the back side of the belt and the lower surface on the bottom side, respectively. The tension band has a fitting portion into which the tension band is press-fitted and fitted, an upper meshing portion meshing with an upper meshing portion of the tension band is formed on an upper surface of the fitting portion, and a lower meshing portion is formed on a lower surface of the tension band. A plurality of blocks each having a lower meshing portion meshing with the portion and having a contact portion in contact with a pulley groove surface on a side surface in the belt width direction, and a tension band is fitted to a fitting portion of each of the blocks. As a result, each block is engaged and fixed to the tension band such that both the contact portion of the block side surface and the side surface of the tension band on the side surface in the width direction of the belt contact the pulley groove surface. Power is transferred by meshing with the meshed part of the belt. A high-load transmission V-belt, wherein a lower back portion is inclined upward toward an inner portion of the fitting portion at a lower corner portion in a tension band press-fitting direction inner portion of the fitting portion of each block. The abutment surface is formed in the range from the position of the pitch line or from the upper position to the lower side of the pitch line, and the lower abutment surface angle α (unit) formed by the lower abutment surface and the vertical plane. °) is β-3 <α <β + 3 with respect to the belt side surface angle β (unit °) formed between the contact portions on the left and right side surfaces of the block and the plane in the vertical direction, and each block has at least the contact portion and A resin portion forming a fitting portion, and a reinforcing material made of a material having a higher elastic modulus than the resin portion; and the reinforcing material at least at upper and lower end positions of a lower back contact surface of the fitting portion of the block. The thickness of the upper resin part is 0.3mm or more High-load drive V-belt. 2. An endless tension band in which a number of upper meshed portions and lower meshed portions arranged in the longitudinal direction of the belt are provided on the upper surface on the back side of the belt and the lower surface on the bottom surface, respectively. The tension band has a fitting portion into which the tension band is press-fitted, and an upper meshing portion meshing with an upper meshing portion of the tension band is formed on an upper surface of the fitting portion, and a lower meshing portion is formed on a lower surface of the tension band. A plurality of blocks each having a lower meshing portion meshing with the portion and having a contact portion in contact with a pulley groove surface on a side surface in the belt width direction, and a tension band is fitted to a fitting portion of each of the blocks. As a result, each block is engaged and fixed to the tension band such that both the contact portion of the block side surface and the side surface of the tension band on the side surface in the width direction of the belt contact the pulley groove surface. Power is transferred by meshing with the meshed part of the belt. A high-load transmission V-belt, wherein a lower back portion is inclined upward toward an inner portion of the fitting portion at a lower corner portion in a tension band press-fitting direction inner portion of the fitting portion of each block. The abutment surface is formed in a range from the lower position to the lower side than the pitch line position, and a lower abutment surface angle α (unit: °) formed by the lower abutment surface and a vertical plane. Is less than or equal to a belt side surface angle β (unit: °) formed between the contact portions on the left and right side surfaces of the block and the plane in the vertical direction, and each block forms at least the contact portion and the fitting portion. A resin portion and a reinforcing member made of a material having a higher elastic modulus than the resin portion, and a thickness of the resin portion on the reinforcing member at least at the upper and lower end positions of the lower back contact surface of the fitting portion of the block. A high-load transmission V-belt having a height of 0.3 mm or more. 3. The V-belt for high load transmission according to claim 1, wherein the thickness of the resin portion on the reinforcing member at least at the upper and lower end positions of the lower back contact surface of the fitting portion of the block is 0.4 mm. A high load transmission V-belt characterized by the above. 4. An endless tension band in which a number of upper meshed portions and lower meshed portions arranged in the belt length direction are provided on the upper surface on the back side of the belt and the lower surface on the bottom side, respectively. The tension band has a fitting portion into which the tension band is press-fitted and fitted, an upper meshing portion meshing with an upper meshing portion of the tension band is formed on an upper surface of the fitting portion, and a lower meshing portion is formed on a lower surface of the tension band. A plurality of blocks each having a lower meshing portion meshing with the portion and having a contact portion in contact with a pulley groove surface on a side surface in the belt width direction, and a tension band is fitted to a fitting portion of each of the blocks. As a result, each block is engaged and fixed to the tension band such that both the contact portion of the block side surface and the side surface of the tension band on the side surface in the width direction of the belt contact the pulley groove surface. Power is transferred by meshing with the meshed part of the belt. A high-load transmission V-belt, wherein a lower back portion is inclined upwardly toward a deeper portion of the fitting portion at a lower corner portion of a deeper portion in a tension band press-fitting direction in a fitting portion of each of the blocks. The abutment surface is formed in the range from the position of the pitch line or from the upper position to the lower side of the pitch line, and the lower abutment surface angle α (unit) formed by the lower abutment surface and the vertical plane. °) is β-3 <α <β + 3 with respect to the belt side surface angle β (unit °) formed between the contact portions on the left and right side surfaces of the block and the plane in the vertical direction, and each block has at least the contact portion and A resin portion forming a fitting portion, and a reinforcing material made of a material having a higher elastic modulus than the resin portion, the upper portion of the lower back contact surface of the fitting portion of the block, a flat surface in the vertical direction On the other hand, there is an upper step that is inclined at an angle smaller than the lower A high-load transmission characterized in that a lower step portion inclined at a larger angle with respect to the vertical plane than the lower rear contact surface is provided at the lower end of the lower rear contact surface. For V-belt. 5. An endless tension band in which a number of upper meshed portions and lower meshed portions arranged in the longitudinal direction of the belt are provided on the upper surface on the back side of the belt and the lower surface on the bottom side, respectively. The tension band has a fitting portion into which the tension band is press-fitted and fitted, an upper meshing portion meshing with an upper meshing portion of the tension band is formed on an upper surface of the fitting portion, and a lower meshing portion is formed on a lower surface of the tension band. A plurality of blocks each having a lower meshing portion meshing with the portion and having a contact portion in contact with a pulley groove surface on a side surface in the belt width direction, and a tension band is fitted to a fitting portion of each of the blocks. As a result, each block is engaged and fixed to the tension band such that both the contact portion of the block side surface and the side surface of the tension band on the side surface in the width direction of the belt contact the pulley groove surface. Power is transferred by meshing with the meshed part of the belt. A high-load transmission V-belt, wherein a lower back portion is inclined upward toward an inner portion of the fitting portion at a lower corner portion in a tension band press-fitting direction inner portion of the fitting portion of each block. The abutment surface is formed in a range from the lower position to the lower side than the pitch line position, and a lower abutment surface angle α (unit: °) formed by the lower abutment surface and a vertical plane. Is less than or equal to a belt side surface angle β (unit: °) formed between the contact portions on the left and right side surfaces of the block and the plane in the vertical direction, and each block forms at least the contact portion and the fitting portion. A resin portion and a reinforcing material made of a material having a higher elastic modulus than the resin portion; and a lower back contact surface with respect to a plane in the vertical direction at an upper end of the lower back contact surface of the fitting portion of the block. The upper step is inclined at a smaller angle than the lower Of the lower end, the high-load drive V-belt, characterized in that the lower step portion is provided with respect to the vertical direction of the plane inclined at an angle greater than the surface abutment lower back. 6. An endless tension band in which a number of upper meshed portions and lower meshed portions arranged in the longitudinal direction of the belt are provided on the upper surface on the back side of the belt and the lower surface on the bottom surface, respectively. The tension band has a fitting portion into which the tension band is press-fitted and fitted, an upper meshing portion meshing with an upper meshing portion of the tension band is formed on an upper surface of the fitting portion, and a lower meshing portion is formed on a lower surface of the tension band. A plurality of blocks each having a lower meshing portion meshing with the portion and having a contact portion in contact with the pulley groove surface on a side surface in the belt width direction, and a tension band is fitted to a fitting portion of each of the blocks. As a result, each block is engaged and fixed to the tension band such that both the contact portion of the block side surface and the side surface of the tension band on the side surface in the width direction of the belt contact the pulley groove surface. Power is transferred by meshing with the meshed part of the belt. A high-load transmission V-belt, wherein a lower back portion is inclined upward toward an inner portion of the fitting portion at a lower corner portion in a tension band press-fitting direction inner portion of the fitting portion of each block. The abutment surface is formed in the range from the position of the pitch line or from the upper position to the lower side of the pitch line, and the lower abutment surface angle α (unit) formed by the lower abutment surface and the vertical plane. °) is β-3 <α <β + 3 with respect to the belt side surface angle β (unit °) formed between the contact portions on the left and right side surfaces of the block and the plane in the vertical direction, and each block has at least the contact portion and A resin portion forming a fitting portion, and a reinforcing material made of a material having a higher elastic modulus than the resin portion, the upper and lower end portions of the lower back contact surface of the fitting portion of the block, High-load transmission characterized by an arcuate section bulging to the back V-belt. 7. An endless tension band in which a plurality of upper meshed portions and lower meshed portions arranged in the belt length direction are provided on the upper surface on the back side of the belt and the lower surface on the bottom side, respectively, corresponding to the up and down directions. The tension band has a fitting portion into which the tension band is press-fitted and fitted, an upper meshing portion meshing with an upper meshing portion of the tension band is formed on an upper surface of the fitting band, and a lower meshing portion is formed on a lower surface of the tension band. A plurality of blocks each having a lower meshing portion meshing with the portion and having a contact portion in contact with the pulley groove surface on a side surface in the belt width direction, and a tension band is fitted to a fitting portion of each of the blocks. As a result, each block is engaged and fixed to the tension band such that both the contact portion of the block side surface and the side surface of the tension band on the side surface in the width direction of the belt contact the pulley groove surface. Power is transferred by meshing with the meshed part of the belt. A high-load transmission V-belt, wherein a lower back portion is inclined upward toward an inner portion of the fitting portion at a lower corner portion in a tension band press-fitting direction inner portion of the fitting portion of each block. The abutment surface is formed in a range from the lower position to the lower side than the pitch line position, and a lower abutment surface angle α (unit: °) formed by the lower abutment surface and a vertical plane. Is α ≦ β with respect to the belt side surface angle β (unit degree) formed between the contact portions on the left and right side surfaces of the block and the vertical plane, and each block forms at least the contact portion and the fitting portion. It is composed of a resin part and a reinforcing material made of a material having a higher elastic modulus than the resin part, and bulges to the back side of the fitting part at the upper and lower ends of the lower back contact surface of the fitting part of the block. A high-load transmission V-belt having an arc portion.