JP2001090787A - V belt for high load transmission - Google Patents

Abstract

(57) [Problem] To provide a high-load transmission V-belt which realizes high dimensional accuracy, has low running noise, and is excellent in durability. A high-load transmission V-belt is provided with an endless tension band, and an upper beam fixed to the tension band at a predetermined pitch along the belt length direction and extending on the upper surface of the tension band in the belt width direction. Are provided on the lower surface side with lower beams 7b extending in the belt width direction, respectively, and the upper and lower beams 7a,
A plurality of blocks of the same shape are provided as contact portions 11a and 11b whose side surfaces in the belt width direction of the belt 7b are in contact with the pulley grooves. One of the thickness centers of the upper beam 7a and the lower beam 7b of each block 7 is shifted in the belt length direction with respect to the other.

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 For example, as disclosed in Japanese Utility Model Laid-Open No. 1-55344, Japanese Utility Model Laid-Open No. 6-69490 and Japanese Patent Laid-Open No. 5-272595, a large number of resin blocks are connected to a rubber tension band. A high-load transmission V-belt locked and fixed using an uneven meshing structure of a block and a tension band has been developed for many years. For example, two V-belts including a fixed sheave and a movable sheave, a driving side and a driven side, are provided. It is used in the field of a continuously variable transmission wound around a speed change pulley.
With this type of V-belt,
The fixing of each block to the tension band is performed not by bonding but by a physical locking state (meshing state).
Specifically, this V-belt is provided with a pair of left and right tension bands a, a arranged in the belt width direction, as shown in the cross section of the belt in FIG. As shown in the figure, upper and lower concave portions e, e,... And lower concave portions f, f,. It is provided. On the other hand, as shown in FIG. 6 (c), a pair of left and right fitting portions h, notched grooves for locking the tension bands a, a on the belt width direction side of each block g, respectively. h is formed, and an upper convex portion i as an upper meshing portion is formed on the upper surface of each fitting portion h.
In addition, lower projections j are provided on the lower surface as lower engagement portions, respectively. Then, the tension bands a, a are press-fitted into the right and left fitting portions h, h of the blocks 7, respectively, and the blocks g are locked and fixed to the tension bands a, a.

In the V-belt, the mesh thickness (t ₂ ) of the tension band a is set to be larger than the mesh gap (t ₁ ) of the block g, and the tension band a is compressed in the thickness direction. An interference is provided so as to be inserted and fitted into the fitting portion h of g. The play between the tension band a and the block g is maintained at a necessary level by an initial interference (s = t ₁ -t ₂ ) provided at the time of assembling the belt. Try to suppress fatigue. Further, as shown in FIG. 6 (a), there is provided a protrusion k in which the tension band a protrudes from the side surface of each block g by about 100 μm, whereby the impact of the block g entering the pulley is reduced, and the belt g Noise can be reduced.

[0004] In order to maintain the effect of noise reduction due to the extra k, even after the belt has been running for a long time, the protrusion amount of the extra k is disclosed in Japanese Utility Model Laid-Open No. 17517/1993. And increase the elastic modulus of rubber,
As proposed in Japanese Patent Application No. 10-290829,
Back striking angle (α) of tension band a fitted to block g
And the buffing of the pulley contact surface of the tension band a to suppress the heat generation of the belt, and to minimize the dimensional change over time of the run-out k. These improvements were effective in suppressing the temporal change of noise in the initial stage of belt running. That is, if the rise k was maintained, the noise could be reduced accordingly.

However, in the process of running the belt, the resin of the block g and the protrusion k of the tension band a are competitively worn, the protrusion amount of the protrusion k gradually decreases, and the noise increases. The belt of the shape and the material will emit a certain level of noise soon. The noise in the latter half of the belt running is caused by the pitch sound when the block g enters the pulley or comes off the pulley due to the limit of the buffering effect of the block k on the pulley entry due to the rise k.

In order to solve the problem of the pitch sound, as described in Japanese Utility Model Laid-Open Publication No. Sho 62-96146 and Japanese Patent Laid-Open Publication No. Hei 7-305745, the pitch at which the blocks are attached to the tension band is fixed. Randomly mixed blocks with chamfered edges at the entrance of the pulley,
An attempt was made to randomize the pitch at which the block enters the pulley.

[0007]

However, since the resin surface on which the block receives the surface pressure of the pulley is located at the position where the reinforcing member exists, the pitch sound of the block is not largely dispersed and the contact area of the block with the pulley is reduced. For this reason, there has been a problem that the resin constituting the block is worn and the resin is chipped. Furthermore, it is necessary to manufacture blocks of different shapes with different molds. If the meshing gap of the blocks, the block pitch width, or the block angle varies, the above-described interference and allowance vary within one belt. As a result, it is conceivable that the surface pressure from the pulley applied to the block becomes non-uniform and the durability reliability of the belt is hindered.

In addition, a block of a single shape is randomly attached to a tension band, that is, a block having a small pitch (for example, 3.0 mm) and a large pitch (for example, 3.3 m).
m), it is conceivable to reduce noise by attaching it to a tension band. However, when used under high load, the force applied to one block increases where many large pitches exist, There is a problem that the polygonal bending of the cord is increased to promote fatigue. Furthermore, in order to randomly attach the blocks to the tension band, it is expected that there will be difficulties in production techniques such as manufacturing a mold for the tension band and how to attach the block to the tension band to assemble the belt.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and it is an object of the present invention to realize a high dimensional accuracy by attaching a block of a single shape to a tension band at an equal pitch, and achieve low noise and durability. An object of the present invention is to obtain a high-load transmission V-belt having excellent reliability.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to a high load transmission V-belt in which a single-shaped block having an upper beam and a lower beam in an endless tension band is attached at a predetermined pitch in the belt length direction. , One of the center of thickness of the upper beam and the center of thickness of the lower beam is shifted from the other in the belt length direction.

Specifically, the invention of the present application provides an endless tension band and an upper beam fixed to the tension band at a predetermined pitch along the belt length direction and extending on the tension band upper surface side in the belt width direction. A plurality of blocks of the same shape each having a lower beam extending in the belt width direction on the lower surface side and having a contact portion in which a side surface in the belt width direction of the upper and lower beams is in contact with a pulley groove. A transmission V-belt, wherein one of the thickness center of the upper beam and the thickness center of the lower beam of each of the blocks is shifted in the belt length direction with respect to the other.

[0012] According to the above configuration, the belt is formed of a single-shaped block and is attached to the tension band at a predetermined pitch. , The dimensional accuracy of the belt is good, and the surface pressure from the pulley on the block is made uniform, so that the durability durability of the belt is also excellent. In addition, as in the case of multiple types of block mounting pitch,
There is no problem that an excessive force is applied to a specific block or the core wire is excessively bent at a large pitch.
Furthermore, since only one type of block needs to be created, the productivity of the belt is good.

Also, since either the center of the thickness of the upper beam or the center of the thickness of the lower beam is displaced from the other in the belt length direction, the contact surface of the upper beam with the pulley and the lower beam When the belt enters the pulley with a timing shifted from the contact surface with the pulley or separates from the pulley, the frequency of the pitch sound generated at that time is dispersed, and the noise during belt running can be reduced.

Thus, the high-load transmission V of the present invention
In the belt, high dimensional accuracy is realized by an easy production method of attaching one type of block to the tension band at a predetermined pitch without using complicated means such as attaching blocks to the tension band at a plurality of types of pitches, This makes it possible to reduce noise during belt running without sacrificing the strength of the block, the wear of the block, the durability of the block, and the durability of the core wire at all.

Here, the upper beam and the lower beam may be configured to have portions overlapping each other when viewed from above. In this case, the block continuously enters the pulley without interruption, the pitch sound of the block is dispersed over a wider range of frequencies, and further noise reduction during belt running can be achieved.

Further, the block is formed by connecting the upper beam and the lower beam by a center pillar, and the center of thickness is the same as the direction of displacement of the beam shifted from the center of the block thickness of the center pillar. Or a reinforcing member embedded so that the center of thickness is located between the center of thickness of the upper beam and the center of thickness of the lower beam. Configuration.

Incidentally, the conventional block is formed of a resin in which a reinforcing member having a high elastic modulus is embedded at a substantially central position in the thickness direction of the block in order to increase the strength. And
For example, as shown in a side view showing the arrangement relationship of the blocks in FIG. 7, an engagement protrusion 1 is provided at a substantially pitch line position on a center pillar of a surface on a belt traveling direction side in each block g.
Engagement holes m are provided on the opposite surfaces, respectively. When the blocks g are mounted on the tension band at an equal pitch, the engagement thereof restricts the displacement of the blocks g in the vertical and horizontal directions. Become. The engagement projections 1 and the engagement holes m are formed of resin. As described in Japanese Patent Application Laid-Open No. 10-73149, the engagement projections 1 have a sufficient shear strength and a reinforcing member. n so that the strength of n is not reduced by drilling or the like for providing the engagement hole m.
Its shape is a truncated cone or hemisphere. And
In such a conventional block g, even if an improvement is made in which one of the upper and lower beams is shifted in the belt length direction from the other, as shown in FIG. 7, the reinforcing member n is located at the center of the block g in the thickness direction. Therefore, the thickness that can be shifted is limited.

However, by arranging the thickness center of the reinforcing member at an appropriate position as described above, even if the reinforcing member is embedded in the block, the beam is displaced in the belt length direction. A large amount can be secured, and noise during belt running can be more effectively reduced.

The portions on the belt inner peripheral side of the belt pitch lines on both surfaces of the block are formed as inclined surfaces inclined toward the center of the block thickness toward the inside of the belt. The inclination angle of the inclined surface on the thickness center side of the lower beam may be larger than that of the inclined surface. Such an inclined surface is provided in order to avoid contact between the blocks when the belt is wound around the pulley, but due to the restriction by the embedding position of the reinforcing member in the block, the inclination of the upper beam in the thickness center side is restricted. The inclination angle of the surface must be small. Therefore, by providing the inclined surface on the center side of the thickness of the lower beam larger than that on the center side of the thickness of the upper beam as in the above configuration, it is possible to avoid contact between adjacent blocks when the belt is wound around the pulley. be able to.

In this case, the block has a fitting portion into which the tension band is press-fitted and fitted, and an upper meshing portion is provided on an upper surface of the fitting portion, and a lower surface thereof is opposed to the upper meshing portion. Lower cross-sections in the block thickness direction are each formed with a symmetrical ridge, and the lower meshing portions are formed such that the height from both ends of the block thickness direction both ends in the lower meshing portion is substantially the same. Is also good. In such a configuration, since there is a difference in height between the lower end of the block in the thickness direction of the block and the lower end of the meshing portion formed of the ridge, the imbalance occurs in the fitting state of the block and the tension band or the bending state of the belt. Is avoided.

The high load transmission V-belt is provided with a number of upper meshed portions and lower meshed portions arranged vertically in the belt length direction on the upper surface on the back side of the belt and the lower surface on the bottom side. A pair of endless tension bands, an upper beam and a lower beam extending in the belt width direction, and a center pillar connecting the upper and lower beams, and a side surface of the upper and lower beams in the belt width direction is a pulley. A pair of fitting portions that are opened at both side surfaces in the width direction of the belt and are press-fitted with the respective tension bands, and are provided on the upper surface of the fitting portions; The upper meshing portion meshing with the upper meshing portion of the upper portion, and a plurality of blocks of the same shape each having a lower meshing portion meshing with the lower meshing portion of the tension band on the lower surface, and a plurality of blocks of the same shape. Tension bands on both mating parts In this configuration, each block is locked and fixed to the tension band at a predetermined pitch in the belt length direction, and power is transmitted and received by the engagement between the engagement portion of the block and the engaged portion of the tension band. Is also good.

[0022]

As described above, in the present invention, the belt is formed of a single-shaped block and is attached to the tension band at a predetermined pitch. The belt can be stopped, the dimensional accuracy of the belt becomes good, and the surface pressure from the pulley applied to the block is made uniform, so that the durability durability of the belt becomes excellent. In addition, as in the case of multiple types of block mounting pitch,
There is no problem that excessive force is applied to a specific block or the core wire is excessively bent at a large pitch,
The durability of the belt is maintained. Furthermore, since only one type of block needs to be created, the productivity of the belt is good.

Since either the center of the thickness of the upper beam or the center of the thickness of the lower beam is shifted in the belt length direction with respect to the other, the contact surface of the upper beam with the pulley and the lower beam are When the belt enters the pulley with a timing shifted from the contact surface with the pulley or separates from the pulley, the frequency of the pitch sound generated at that time is dispersed, and the noise during belt running can be reduced.

Thus, the high-load transmission V of the present invention
In the belt, high dimensional accuracy is realized by an easy production method of attaching one type of block to the tension band at a predetermined pitch without using complicated means such as attaching blocks to the tension band at a plurality of types of pitches, This improves the durability of the belt without sacrificing the strength of the block, the abrasion of the block, the durability of the block and the durability of the core wire at all, and further reduces noise when the belt runs. Become.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a high-load transmission V-belt B according to an embodiment of the present invention. The V-belt B has a pair of left and right endless tension bands 1, 1 and belts 1 A large number of blocks 7, which are continuously locked and fixed in the longitudinal direction,
7, ... Each tension band 1 has a plurality of core wires 1b, 1b,... (Core body) of high strength and high elastic modulus, such as aramid fibers, arranged in a spiral shape and embedded in a shape-retaining layer 1a made of hard rubber. The upper surface of each tension band 1 is provided with groove-shaped upper concave portions 2, 2,... As upper meshed portions having a constant pitch and extending in the belt width direction corresponding to the respective blocks 7, and the lower surface is provided with the upper The lower concave portions 3, 3,... Are respectively formed as lower engaged portions extending at a constant pitch in the belt width direction corresponding to the concave portions 2, 2,. 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 forming the shape-retaining la is excellent in heat resistance by being reinforced by mixing short fibers such as aramid fibers and nylon fibers with H-NBR rubber reinforced with, for example, zinc methacrylate. And it is hard to be permanently deformed. 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.
Is composed of upper and lower beams 7a and 7b extending in the belt width direction (left and right direction), and a center pillar 7c for connecting the left and right central portions of both beams 7a and 7b up and down, and is substantially H-shaped. Is formed. Notched groove-shaped fitting portions 8, 8 opened on the left and right sides in the belt width direction are formed so as to be surrounded by the upper and lower beams 7a, 7b and the center pillar 7c. Then, the tension bands 1 are detachably fitted to the fitting portions 8 in the width direction. Also, the surfaces forming the side surfaces of the block 7 of the upper beam 7a and the lower beam 7b are respectively formed by the upper contact portions 1 that contact the pulley groove surfaces (not shown) of the V pulley.
1a, the lower contact portion 11b. The center of the thickness of the upper beam 7a is closer to the belt traveling direction than the center of the thickness of the lower beam 7b (the front side in FIG.
To the left). Such a shape can be easily manufactured as long as the mold of the block 7 is formed. Further, in a top view of the V-belt B, the upper beam 7a and the beam 7b have portions overlapping each other. In addition,
The positional relationship between the upper and lower beams 7a and 7b may be reversed (the center of the thickness of the lower beam 7b is shifted toward the belt traveling direction with respect to the center of the thickness of the upper beam 7a).

Further, the belt angle formed by the left and right side surfaces of the block 7 is the same as the angle of the pulley groove surface.
Then, the tension bands 1, 1 are press-fitted into the fitting portions 8, 8 of the respective blocks 7 so as to be fitted, so that the blocks 7, 7,.
Are continuously locked and fixed to the tension bands 1 and 1 in the belt length 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.
On the lower wall surface of the fitting portion 8, lower projections 10 each formed of a ridge as a lower engagement portion meshing with each lower recess 3 on the lower surface of the tension band 1 are formed in parallel with each other. ing. Here, the height of both ends in the block thickness direction of the lower protrusion 10 from the block lower end is substantially the same.
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 are connected to the tension bands 1 and 1 in the belt length direction. The engagement is fixed by press-fitting.
Of the block 7 and the contact portion 11 as the side surface of each block 7 contact the pulley groove surface, and the upper and lower convex portions 9 and 10 (meshing portions) of the block 7 and the upper and lower concave portions 2 of each tension band 1. , 3 (engaged part), power is transmitted and received.

Each of the blocks 7 is made of a hard resin material, and has a reinforcing member 12 made of a lightweight aluminum alloy or the like embedded therein. The reinforcing member 12 includes, for example, upper and lower protrusions 9 and 10 (meshed portions with the tension band 1) and left and right side contact portions 11 and 11 (sliding contact portions with the pulley groove surface).
In this case, it is embedded in the hard resin and does not appear on the surface of the block 7 (that is, these portions are made of the hard resin), but other portions may be exposed on the surface of the block 7.

The reinforcing member 12 has its center at the center of the block thickness of the center pillar 7c (here, the block thickness means the thickness excluding the engaging projections and the engaging holes. The same applies hereinafter). Are located on the side of the engagement projection 13 (the center side of the thickness of the upper beam 7a). In other words, the reinforcing member 12 is embedded in the block such that the thickness center of the reinforcing member 12 is located between the thickness center of the upper beam 7a and the thickness center of the lower beam 7b.

Further, a truncated cone-shaped engaging projection 13 is provided on the center pillar 7c on the surface of the block 7 on the belt running direction side (front side in FIG. 1, left side in FIG. 2), and the other surface is provided. Is provided with an engagement hole 14 that engages with the engagement protrusion 13. And block 7
When is attached to the tension band 1, the engagement of the engagement projections 13 and the engagement holes 14 restricts the displacement of the block in the vertical and horizontal directions, and suppresses the swing of the block. The lower portion of the top surface of the engagement protrusion 13 is formed as an inclined surface extending downward and inward from the pitch line in consideration of the bending of the belt.

The lower part (the inside of the belt) of the surface of the block 7 on the side of the engagement projection 13 and the side of the engagement hole 14 is bent to a certain curvature when the belt is wound around the pulley, and the blocks 7, Since it is necessary to avoid contact between the belts 7, they are formed on an inclined surface directed toward the center of the block thickness toward the inside of the belt. Block 7 of V belt B
Then, as shown in FIG. 2, the center of the thickness of the reinforcing member 12 is larger than the center of the block thickness of the center pillar 7c.
Side (the thickness center side of the upper beam 7a), the inclination angles on both sides are not equal,
The surface on the side of the engagement protrusion 13 (on the center side of the thickness of the upper beam 7a) has a small angle, and the surface on the side of the engagement hole 11b (the center on the thickness side of the lower beam 7b) has a large angle.

As a feature of the present invention, the belt is formed of a single-shaped block 7 and is attached to the tension bands 1 and 1 at a predetermined pitch. Is minimized, and the V-belt B has good dimensional accuracy,
Since the surface pressure from the pulley applied to the block is made uniform, the durability and reliability are also excellent. In addition, there is no problem that an excessive force is applied to a specific block or that a core wire is excessively bent in a portion having a large pitch, as in a case where a plurality of types of mounting pitches of the block 7 are used. Furthermore, since only one type of block 7 needs to be created, the productivity of the belt is good.

Since the center of the thickness of the upper beam 7a is shifted from the center of the thickness of the lower beam 7b in the belt advancing direction, the contact surface 11a of the upper beam 7a with the pulley and the pulley of the lower beam 7b are And enters the pulley at a different timing from the contact surface 11b or separates from the pulley. Further, since the upper beam 7a and the lower beam 7b have an overlapping portion in a top view, the block 7 continuously enters the pulley without interruption. From the above, the pitch sound of the block 7 is dispersed over a wide range of frequencies, and the noise of the V-belt B during traveling of the belt is significantly reduced as compared with the related art.

As shown in FIG. 2, the embedding position of the reinforcing member 12 in the block 7 is such that the center of thickness of the reinforcing member 12 is closer to the engaging projection 13 than the center of the block thickness of the center pillar 7c (the upper beam). In other words, since the thickness center of the reinforcing member 12 is located between the thickness center of the upper beam 7a and the thickness center of the lower beam 7b, FIG. As shown (the same parts are denoted by the same reference numerals as in FIG. 2), the belt of the upper beam 7a is compared with the case where the thickness center of the reinforcing member 12 is aligned with the block thickness center of the center pillar 7c. A large amount of deviation in the traveling direction is ensured, and the effect of reducing noise during belt running can be more appropriately performed.

The portion of the belt 7 on both sides of the belt pitch line on the inner peripheral side of the belt 7 is formed as an inclined surface which is inclined toward the center of the thickness of the block 7 toward the inside of the belt. The inclination angle of the inclined surface on the engagement hole 14 side (the thickness center side of the lower beam) is larger than that on the 13 side (the center of the upper beam thickness). Such an inclined surface is provided in order to avoid contact between the blocks 7 when the V belt B is wound around the pulley, and the reinforcing member 1 embedded in the block 7 is provided.
2 is located closer to the engagement protrusion 13 than the center of the thickness of the block 7 of the center pillar 7c (toward the center of the thickness of the upper beam). The angle must be small.
However, by providing the inclined surface on the side of the engagement hole 14 larger than that on the side of the engagement protrusion 13, the contact between the adjacent blocks 7, 7 is avoided.

Further, since the height of both ends in the thickness direction of the block 7 in the lower convex portion 10 from the lower end of the block 7 is substantially the same, the blocks 7 in both ends in the thickness direction of the lower convex block 7 are provided. As in the case where there is a difference in height from the lower end, imbalance does not occur in the fitted state of the block and the tension band or the bent state of the V-belt B.

Thus, the high-load transmission V of the present invention
In the belt, high dimensional accuracy is realized by an easy production method of attaching one type of block to the tension band at a predetermined pitch without using complicated means such as attaching blocks to the tension band at a plurality of types of pitches, This improves the durability of the belt without sacrificing the strength of the block, the abrasion of the block, the durability of the block and the durability of the core wire at all, and further reduces noise when the belt runs. Become.

[0041]

Next, a specific embodiment will be described. <Preparation of Evaluation Belt> For test evaluation, a high load transmission V-belt having the following components was prepared. Table 1 shows the configuration of each belt. -Example 1-The belt length is 612 mm, the width of the block at the belt line is 25 mm, the belt angle is 26 °, and the inclination angle of the inclined surface below the block is 3.2 on both the engaging protrusion side and the engaging hole side.
°, the block thickness is 2.9 mm, the pitch of the blocks in the belt length direction is a constant pitch of 3.0 mm, the number of blocks is 204, and as shown in FIG. 7, the center of the thickness of the upper beam and the center pillar Each block has a center of thickness at the center pillar of the block (an engagement protrusion and an engagement). Example 1 was a high-load transmission V-belt that was insert-molded in a phenolic resin so that the thickness of the reinforcing member coincided with the thickness center of the reinforcing member. —Example 2— As shown in FIG. 3, the belt has the same configuration as that of Example 1 except that the upper beam is shifted to the engagement protrusion side by 0.2 mm with respect to the lower beam in the belt length direction. Example 2 was a V-belt. -Example 3-The inclination angle of the inclined surface below the block is 2.0 on the engagement protrusion side.
°, and the engagement hole side was 4.5 °, and as shown in FIG.
The point shifted in the belt length direction and the center of the reinforcing member are 0.25 mm from the center of the thickness at the center pillar portion of the block.
Example 3 was a V-belt having the same configuration as Example 1 except that the V-belt was shifted to the engagement protrusion side.

[0042]

[Table 1] <Test evaluation method> A durability running test was performed on the belts of each example, and the belt noise was measured both at the initial stage of the running and at the running time after a lapse of a predetermined time. The belt durability running test conditions are as follows. That is, as shown in FIG. 4, a driving pulley 21 having a diameter of 126 mm and a diameter of 70.8 m
m is wound around the driven pulley 22, and a load is applied to the driven pulley 22 so that the axial load becomes 1764 N, and the driving pulley 21 is set to 63.4 N · at an ambient temperature of 100 ° C. m drive torque and 5285 rpm
And the belt 23 was run. In addition,
At this time, a torque of 113.2 N · m was generated in the driven pulley 22, and the driven pulley 22 was rotated at a rotation speed of 9435 rpm.

On the other hand, the noise test of the belt 23 of each example was performed using the noise level meter by removing the belt 23 from the running test device at each evaluation time. That is, as shown in FIG. 5, the belt 23 of each example is wound around the drive pulley 21 having a diameter of 64 mm and the driven pulley 22 having a diameter of 128 mm, and a load is applied to the driven pulley 22 so that the axial load becomes 1960N. ,
At room temperature, the driven pulley 22 is set to no load,
Is rotated at a rotation speed of 2500 rpm, and the microphone is located at a position 50 mm closer to the driven pulley 22 from the driving pulley 21 and 100 mm away from the driving pulley 21 on a plane passing through the rotation axis of the driving and driven pulleys 21 and 22. Was installed and the noise was measured. <Test Evaluation Results> Table 2 shows the test evaluation results of the V belts according to the respective examples. According to the table, Example 2 is 1 to 1 compared to Example 1.
The noise is reduced by 2 dB. This is because the timing of the upper beam and the lower beam entering the pulley or coming off the pulley is shifted, and the frequency of the pitch sound of the block is dispersed.

In the meantime, in the V belt of Example 2, the center of thickness of the reinforcing member coincides with the center of the block thickness of the center pillar portion. However, in order to secure the block strength, the thickness of the reinforcing member is designed to be large. Therefore, the amount of deviation of the upper beam from the lower beam is only 0.2 mm. In Example 3, since the thickness center of the reinforcing member is shifted by 0.25 mm from the center of the block of the center pillar toward the engagement protrusion, the thickness center of the upper beam is shifted in the belt length direction from the thickness center of the lower beam. The deviation was as large as 0.5 mm. As a result, the upper beam and the lower beam have an overlapping portion in a top view, and the frequency of the pitch sound when the block enters the pulley is more widely dispersed, so that the noise during belt running can be reduced. This can be more effectively achieved. The effect can be confirmed also in the above-described embodiment, and the noise of Example 3 can be reduced by 4 to 5 dB as compared with Example 2.

[0045]

[Table 2]

[Brief description of the drawings]

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

FIG. 2 is a side view showing an arrangement state of blocks in a high-load transmission V-belt according to Embodiment 1 of the present invention (a V-belt according to Example 3).

FIG. 3 is a side view showing an arrangement state of blocks in a high-load transmission V-belt according to another embodiment of the present invention (V-belt according to Example 2).

FIG. 4 is a schematic view showing a layout of a belt durability test apparatus.

FIG. 5 is a schematic diagram showing a layout of a belt noise test device.

6A is a sectional view of a high-load transmission V-belt according to a conventional example, FIG. 6B is a side view of a tension band, and FIG. 6C is a side view of a block.

FIG. 7 is a side view showing an arrangement state of blocks in a high-load transmission V-belt according to a conventional example (V-belt according to Example 1).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tension band 1a Core wire 1b Shape-retaining rubber 2 Upper concave part 3 Lower concave part 4 Canvas 7 Block 7a Upper beam 7b Lower beam 7c Center pillar 8 Fitting part 9 Upper convex part 10 Lower convex part 11a Upper contact part 11b Lower Side contact part 12 Reinforcement member 13 Engagement projection 14 Engagement hole 21 Drive pulley 22 Follower pulley 23 Belt a Tension band e Upper concave part f Lower concave part g Block h Fitting part i Upper convex part j Lower convex part k t ₁ back abutting angle of the engagement gap t ₂ meshing thickness α tension band

Claims (8)

[Claims] 1. An endless tension band, an upper beam which is fixed to the tension band at a predetermined pitch side by side in the belt length direction and extends in the belt width direction on the tension band upper surface side and extends in the belt width direction on the lower surface side. A high-load transmission V-belt having a plurality of blocks of the same shape each having a lower beam and having a contact portion in which a side surface in a belt width direction of the upper and lower beams is in contact with a pulley groove, A high load transmission V-belt, wherein one of the thickness center of the upper beam and the thickness center of the lower beam of each block is shifted from the other in the belt length direction. 2. The high-load transmission V-belt according to claim 1, wherein the upper beam and the lower beam have portions overlapping each other when viewed from above. 3. The V-belt for high load transmission according to claim 1, wherein the block is formed by connecting an upper beam and a lower beam by a center pillar, and has a thickness center. A V-belt for high-load transmission, comprising a reinforcing member buried in a direction shifted from the center of the block thickness of the center pillar in the same direction as the direction of the shifted beam. 4. The high-load transmission V-belt according to claim 1, wherein the block has a thickness center located between the thickness center of the upper beam and the thickness center of the lower beam. A high-load transmission V characterized by comprising a reinforcing member buried so as to
belt. 5. The high-load transmission V-belt according to claim 3, wherein a portion on the belt inner peripheral side of the belt pitch lines on both surfaces of the block is in the direction of the block thickness center toward the inside of the belt. Characterized in that the inclination angle at the center of the lower beam at the center of the thickness of the lower beam is greater than that at the center of the thickness of the upper beam at the inclination angle of the upper beam. Transmission V-belt. 6. The high-load transmission V-belt according to claim 5, wherein the block has a fitting portion into which the tension band is press-fitted and fitted, and an upper meshing portion is provided on an upper surface of the fitting portion. A lower meshing portion is formed on the lower surface, the lower meshing portion opposing the upper meshing portion and having a symmetrical cross section in the block thickness direction, and a lower end of the block at the both ends in the block thickness direction at the lower meshing portion. A high-load transmission V-belt, the heights of which are substantially the same. 7. A pair of endless tension bands provided with a plurality 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 side, respectively. And a contact portion formed of an upper beam and a lower beam extending in a belt width direction and a center pillar connecting the upper and lower beams, and a side surface of the upper and lower beams in a belt width direction serving as a pulley groove. The tension band has a pair of fitting portions which are opened on both side surfaces in the width direction of the belt, and each of the tension bands is press-fitted and fitted, and meshes with the upper meshing portion of the tension band on the upper surface of the fitting portion. The upper meshing portion includes a plurality of blocks of the same shape each having a lower meshing portion meshed with the lower meshed portion of the tension band on the lower surface, and a tension band is formed on both fitting portions of the blocks. By mating each, each block A high-load transmission V-belt, which is locked and fixed to the tension band at a predetermined pitch in the belt length direction, and power is transmitted and received by meshing between a meshing portion of the block and a meshed portion of the tension band. The thickness center of the upper beam or the thickness center of the lower beam is shifted in the belt length direction with respect to the other, and the thickness center of the block is shifted from the block thickness center of the center pillar. A high-load transmission V-belt, comprising a reinforcing member buried in the same direction as the direction of the shifted beam. 8. The high-load transmission V-belt according to claim 7, wherein the upper beam and the lower beam have portions overlapping each other when viewed from above.