JP3464922B2 - V belt for high load transmission - Google Patents

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 high load transmission V-belts.

[0002]

2. Description of the Related Art Conventionally, a block is composed of a large number of blocks and a tension band made of hard rubber, and power is transferred between the tension band and each block by engaging a convex portion of the block with a concave portion of the tension band. V-belts for high-load transmission of the type to be performed are well known and used in the field of continuously variable transmissions. In this V-belt, in order to ensure its bendability, each block is fixed to the tension band not by adhesion but by physical engagement (meshing).

By the way, in such a high-load transmission V-belt, each block is formed of a hard resin material, and a reinforcing member for reinforcement is provided inside at least the meshing portion with the tension band and the pulley groove surface. The reinforcing member is embedded so that the contact portion is a resin portion, and the reinforcing member is composed of upper and lower beam portions respectively located on the upper and lower sides of the tension band, and a pillar portion connecting the base end portions of these upper and lower beam portions. ing.

However, during high load transmission by this belt,
When stress is repeatedly applied to the base end portion (root portion) of the upper beam portion located above the tension band (outward in the radial direction of the pulley) of the reinforcing member in the block, the upper beam portion is broken from the root portion. The power transmission by the belt becomes impossible.

Therefore, conventionally, as disclosed in Japanese Utility Model Laid-Open No. 5-3692, the left and right upper beam portions extending in the belt width direction in the reinforcing member of the block are positioned at the base end portions (the central portions of the entire left and right sides). It has been proposed that the curved portion is arched so as to be higher than the tip portions (both end portions of the entire left and right sides) to reduce the stress generated at the root portion of the upper beam portion and prevent the breakage thereof.

[0006]

By the way, in the above-mentioned proposed example, although the upper beam portion of the reinforcing member in the block is prevented from being broken, high load transmission can be performed.
On the other hand, when a tension is applied to the belt, the block bites into the pulley groove, the resistance when the belt comes out of the pulley groove increases, and the tension band is cut early.

That is, when the belt is wound around a pulley and power is transmitted, the block in the pulley groove is pushed downward from the tension band (toward the pulley center) and pushed into the pulley groove. The shearing force transmitting rotation between the tension band and the pulley works, and the reinforcing member of the block is deformed in the elastic region by the pushing force and the shearing force, and the resin portion of the block is compressed. After that, when the block comes out of the pulley groove, the pushing force and the shearing force disappear, and the block separates from the pulley groove, but at that time, the block bites into the pulley groove and stays stretched. It is considered that the tension band comes to be pulled out of the pulley groove and separated from the pulley groove, and such pulling out of the block promotes fatigue fracture of the tension band, leading to early damage.

The present invention has been made in view of the above circumstances, and an object thereof is to appropriately change the characteristics of a sliding contact portion made of a resin portion in a belt block so that the belt block is pushed into the pulley groove. Prevent the tension band from prematurely cutting while securing the high load transmission of the belt while suppressing the bite into the pulley groove when it comes out and allowing the block to come out of the pulley groove without pulling out the tension band. To do so.

[0009]

In order to achieve the above object, according to the present invention, the upper beam portion of the reinforcing member of the block is formed into a curved shape or the like, thereby reducing the stress on the root portion of the belt. The high load transmission can be performed, and the coefficient of friction between the contact portion of the block and the pulley groove surface is set in association with the belt side surface angle θ.

Specifically, in the invention of claim 1, a tension band in which a large number of upper meshed portions and lower meshed portions arranged in the belt length direction are provided on the upper and lower surfaces in a vertically corresponding manner,
On the side surface in the belt width direction, the upper wall surface has an upper meshing portion that meshes with the upper meshing portion of the tension band, and the lower wall surface has a lower meshing portion that meshes with the lower meshing portion of the tension band. A groove and a number of blocks located on the upper and lower sides of the fitting groove and provided with upper and lower contact portions that come into contact with the pulley groove surface, and a tension band is fitted into the fitting groove of each block. By doing so, each block is engaged and fixed to the tension band, each block is provided with a reinforcing member embedded in the resin portion so that at least the upper and lower meshing portions and contact portions are formed of the resin portion, The target is a high-load transmission V-belt in which the reinforcing member includes upper and lower beam portions respectively positioned on the upper and lower sides of the fitting groove, and a pillar portion connecting the base end portions of the upper and lower beam portions.

The upper beam portion of the reinforcing member is
Incline downward from the base end toward the tip.
In addition, the beam angle between the vertical center line of the upper beam portion and the pulley groove surface closer to the pulley center than the contact position of the upper contact portion on the side surface of the block is 90 ° or more. I shall.

Further, the coefficient of friction μ between the contact portion of the block and the pulley groove surface is defined by the belt side surface angle θ between the left and right side surfaces of the belt and the vertical plane (the block side surface angle =
½ tan θ + 0.0 for 1/2) of the belt angle
Set to 5.

If the friction coefficient μ between the contact portion of the block and the pulley groove surface is μ> tan θ + 0.05, the effect of suppressing the bite into the pulley groove of the block is insufficient and fatigue failure of the tension band occurs. Since it cannot be prevented, the friction coefficient μ is ta
nθ + 0.05 or less.

With this configuration, the following operational effects can be obtained. That is, in a state where the belt is transmitted between the block and the tension band, a shearing force in the belt length direction is generated between the meshing part of the tension band and the meshing part of the block meshing with the tension band between the blocks and the tension band. A three-dimensional force is applied by the pressing force of the tension band pressing the lower meshing portion of the block toward the pulley center side, but the above force is not received when the belt is not wound around the pulley. The root portion of the upper beam portion of the block is subjected to tensile stress due to the repeated stress in between. Further, due to the shearing force, one side portion of the reinforcing member in the belt length direction receives tensile stress and the other side portion receives compressive stress. When the block receives a pressing force from the tension band and is pressed against the pulley groove surface, the block receives a reaction force in a direction perpendicular to the pulley groove surface at the upper contact portion in the upper portion of the tension band. Then, in the case of the conventional structure in which the beam angle formed by the vertical center line of the upper beam portion of the reinforcing member and the pulley groove surface on the pulley center side of the contact position of the upper contact portion of the block is smaller than 90 °, Due to the component force of the reaction force from the pulley groove surface, an upward bending moment is generated in the upper beam portion such that the tip portion is pushed upward and bends, and this upward bending moment causes tensile stress at the root portion of the upper beam portion. To do. As a result of these, tensile stress acts not only on the tensile stress due to the shearing force but also on the upward bending moment at the root portion of the upper beam portion, and the tensile stress increases due to the synergistic action of both,
This increased tensile stress causes fatigue fracture at the root of the upper beam.

On the other hand, in the present invention, the above-mentioned reinforcing member
Tilt downward from the base end toward the tip.
Since it is a slanted substantially straight plate and the beam angle formed by the vertical center line of the upper beam portion and the pulley groove surface on the pulley center side of the contact position of the upper contact portion of the block is 90 ° or more, Whether the above-mentioned upward bending moment does not occur (when the beam angle is 90 °), or conversely, the tip part is pushed downward by the upper beam part due to the component force of the reaction force from the pulley groove surface and bends. A downward bending moment is generated, and this downward bending moment causes a compressive stress at the root portion of the upper beam portion (when the beam angle is larger than 90 °). Therefore, only the tensile stress due to the shearing force is directly applied to the root portion of the upper beam portion, or the tensile stress reduced by the amount of the compressive stress due to the downward bending moment acts on the root portion of the upper beam portion, and the large tensile force is applied to the root portion of the upper beam portion. It is possible to prevent the tensile stress from acting and prevent the root portion of the upper beam portion from being fatigue-fractured by the tensile stress, and it is possible to further increase the transmission load of the belt without increasing the weight of the block. .

Further, the friction coefficient μ between the contact portion made of the resin portion of the block and the pulley groove surface is μ ≦ ta with respect to the belt side surface angle θ formed by the left and right side surfaces of the belt and the plane in the vertical direction.
Since nθ + 0.05, the friction coefficient μ is low. For this reason, even if the belt is wound around the pulley and the contact portion made of the resin portion of the block is compressed by the pushing force and the shearing force from the tension band, the block does not bite into the pulley groove, and then the block moves from the pulley groove. When pulling out, it does not remain stretched inside the pulley groove, and the block can be separated from the pulley groove without the need to pull out with a tension band, and fatigue failure of the tension band can be suppressed and early damage can be prevented. . As described above, while increasing the transmission load of the belt, it is possible to smoothly pull out the block from the pulley groove, prevent the tension band from being cut early, and extend the life of the belt.

According to a second aspect of the present invention, in the same high load transmission V-belt as the object of the first aspect of the invention, the upper beam portion of the reinforcing member in each block is bent at the intermediate portion.
From the base end to the middle,
It is the base end side that inclines toward the lower side, and the middle part
From the tip to the tip, it extends from the tip side, which extends in the belt width direction.
The beam angle formed by the vertical center line on the base end side of the upper beam portion of the reinforcing member and the pulley groove surface closer to the pulley center than the contact position of the upper contact portion of the block is 9
While that is 0 ° or more, bent so as to form a beam angle between the pulley center side of the pulley groove surface than the contact position of the upper contact portion of the upper and lower center line and the block side surface of the front end portion is smaller than 90 ° It is assumed that

Further, the friction coefficient μ between the contact portion of the block and the pulley groove surface is μ ≦ tan θ with respect to the belt side surface angle θ formed by the left and right side surfaces of the belt and the vertical plane.
+0.05.

In this way , the bending at the middle portion of the reinforcing member
Since the beam angle formed by the vertical center line on the tip end side of the upper beam part and the pulley groove surface on the pulley center side of the contact position of the upper contact part of the block is smaller than 90 °, the block height is Can be made smaller. That is, when the beam angle of the entire upper beam portion is 90 ° or more as in the invention of claim 1, the height of the block increases to secure the fitting groove on the side surface of the block. Since the beam angle formed by the vertical center line only on the base end side of the beam part and the pulley groove surface on the pulley center side of the contact position of the upper contact part of the block is 90 ° or more, the height of the block can be reduced. . As a result, the block can be made smaller and lighter to reduce the block vibration and the centrifugal tension of the belt when the belt is running, and prevent the tension band from being cut early due to heat generation or wear, thereby extending the service life of the belt. it can.

As in the first aspect of the present invention, since the friction coefficient μ between the contact portion made of the resin portion of the block and the pulley groove surface is low, the block is moved to the pulley groove after the belt is wound around the pulley. When the block is pulled out, the block does not bite into the pulley groove and stays stretched, and pulling out of the block by the tension band can be eliminated to prevent early breakage of the tension band .

[0021] In the invention of 請 Motomeko 3, it is positioned below the proximal end of the position of the distal end portion of the upper and lower center line of the lower beam part of the reinforcing member. By so doing, similarly to the invention of claim 1, the tensile stress on the root portion of the lower beam portion of the reinforcing member can be reduced, and the root portion of the lower beam portion can be prevented from fatigue failure, and the block weight is reduced. It is possible to further increase the transmission load of the belt without increasing.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIGS. 1 to 3 show a high load transmission V-belt B according to Embodiment 1 of the present invention.
The belt B includes a pair of left and right endless tension bands 1, 1
, And a large number of blocks 7, 7, ... Continuously engaged and fixed to the tension bands 1, 1 in the belt longitudinal direction. Each of the tension bands 1 includes a plurality of core wires 1b, 1 having high strength and high elastic modulus such as aramid fibers inside a shape-retaining layer 1a made of hard rubber.
b, ... (Core body) are spirally arranged and embedded, and the upper surface of each tension band 1 corresponds to each block 7 and is a groove as an upper meshing portion having a constant pitch and extending in the belt width direction. -Like upper recesses 2, and lower surfaces of the lower recesses 3, 3, ..., which are lower meshing portions having a constant pitch and extending in the belt width direction, corresponding to the upper recesses 2, 2, ... on the lower surface. Are formed respectively. In addition, on the upper and lower surfaces of the tension band 1,
The canvases 4, 4 are adhered for the purpose of improving their wear resistance.

The hard rubber forming the shape-retaining layer 1a is excellent in heat resistance and is permanent by reinforced, for example, H-NBR rubber reinforced with zinc methacrylate and short fibers such as aramid fiber and nylon fiber. Hard rubber that is difficult to deform is used. The hardness of this hard rubber requires a rubber hardness of 75 ° or more when measured with a JIS-C hardness meter.

On the other hand, each of the blocks 7 has notch-shaped fitting grooves 8 and 8 on which the tension bands 1 are detachably fitted from the width direction on the left and right side surfaces in the belt width direction. 8 has upper and lower contact portions 11, 11 that come into contact with the pulley groove surface P1 of the pulley P on both upper and lower sides, and the tension bands 1, 8 are respectively provided in the fitting grooves 8, 8 of each block 7. , 1 are continuously fixed to the tension bands 1, 1 in the belt longitudinal direction.

That is, on the upper wall surface of each fitting groove 8 in each block 7, an upper convex portion 9 formed of a convex strip as an upper meshing portion that meshes with each upper concave portion 2 on the upper surface of the tension band 1 is formed.
On the lower wall surface of the fitting groove 8, lower projections 10 are formed in parallel with each other, each of which is composed of a ridge as a lower meshing part that meshes with the lower recesses 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, ... It is configured to be engaged and fixed, and in this engaged state, the contact portions 11, 11 which are the left and right side surfaces of each block 7 are in contact with the pulley groove surface P1 (the outer side surface of each tension band 1 is also the pulley groove surface P1.
May be contacted with).

As shown in FIGS. 1 and 2, each of the blocks 7 has a resin portion 16 made of a hard resin material. Inside the resin portion 16, a lightweight aluminum is provided so as to be located in the approximate center of the block 7. A reinforcing member 12 made of an alloy or the like is embedded. The reinforcing member 12 is embedded in a hard resin at the upper and lower convex portions 9 and 10 (meshing portion with the tension band 1) and the contact portions 11 and 11 on the left and right side surfaces, for example, and is embedded in the block 7.
Although it does not appear on the surface (that is, these parts are
Of the hard resin material), and other portions may be exposed on the surface of the block 7. The reinforcing member 12 includes a pair of left and right upper beam portions 13 and 13 and lower beam portions 14 and 14 extending in the belt width direction (horizontal direction).
And a pillar portion 15 that integrally connects the base end portions of the left and right upper beam portions 13 and the base end portions of the lower beam portions 14 and 14 to each other in the vertical direction, and has a substantially H shape. Has been formed.

Further, as shown in FIG. 1, each of the upper beam portions 13 of the reinforcing member 12 has a substantially straight plate shape, and its base end portion (connection portion with the upper end portion of the pillar portion 15) to the tip end portion. The left and right upper beam portions 13, 13 are inclined so as to be directed downward, and when viewed as a whole, the left and right upper beam portions 13 and 13 have a mountain shape bent in a substantially dogleg shape so as to project above both end portions. I am doing it. The beam angle α formed by the vertical center line L of the upper beam portion 13 and the pulley groove surface P1 located closer to the center of the pulley P than the contact position of the upper contact portion 11 of the block 7 is 90 ° or more (α ≧ 90 °).

The left and right contact portions 1 of each of the blocks 7 are
Friction coefficient μ between each of Nos. 1 and 11 and the pulley groove surface P1
However, the right and left side surfaces of the belt B and the plane O in the vertical direction
Side surface angle θ with the plane passing through the widthwise center of
For (angle of side surface of block 7 = 1/2 of belt angle), μ ≦ tan θ + 0.05. The friction coefficient μ between the contact portion 11 of the block 7 and the pulley groove surface P1
Is μ> tan θ + 0.05, the effect of suppressing the bite into the pulley groove of the block 7 is insufficient, and fatigue failure due to pulling out of the tension band 1 cannot be prevented, so that μ ≦ tan θ
+0.05.

Therefore, in this embodiment, the reinforcing member 12 embedded in each block 7 of the belt B is formed.
Of the upper beam portions 13, each of the upper beam portions 13 is inclined downward from the base end portion (the connection portion with the upper end portion of the pillar portion 15) toward the tip end portion. Since the beam angle α formed by the vertical center line L and the pulley groove surface P1 closer to the pulley center than the contact position of the upper contact portion 11 of the block 7 is 90 ° or more, the transmission state in which the belt B is wound around the pulley P When the block 7 is pressed against the pulley groove surface P1 by receiving a pressing force from the tension band 1 and the upper contact portion 11 of the block 7 receives a reaction force from the pulley groove surface P1 in a direction perpendicular thereto, When the angle α is 90 °, the upper beam portion 13 does not generate an upward bending moment in which the tip portion is pushed upward by the upper beam portion 13 due to the reaction force from the pulley groove surface P1 to bend. From this, the belt B and the pulley P are attached to the root portion 13a of the upper beam portion 13.
In the transmission state between them, only the tensile stress due to the shear force in the belt length direction acting between each block 7 of the belt B and the tension band 1 acts as it is.

On the other hand, when the beam angle α is larger than 90 °, the tip end portion of the upper beam portion 13 is pushed downward by the upper beam portion 13 to bend due to the downward component force of the reaction force from the pulley groove surface P1. A downward bending moment is generated, and this downward bending moment causes the root portion 13 of the upper beam portion 13 to move.
A compressive stress is generated at a. Therefore, the upper beam portion 13
In addition to the tensile stress due to the shearing force in the belt length direction, the compressive stress due to the downward bending moment acts on the root portion 13a of the above, and the tensile stress due to the shearing force is reduced by canceling both stresses.

As a result of these, a large tensile stress does not act on the root portion 13a of the upper beam portion 13, and it is possible to prevent the root portion 13a of the upper beam portion 13 from fatigue breaking due to the tensile stress. That is, block 7
Therefore, the transmission load of the belt B can be increased without increasing the weight of the belt B.

The coefficient of friction μ between the left and right contact portions 11 of the block 7 and the pulley groove surface P1 is the belt side surface angle θ.
Since μ ≦ tan θ + 0.05, the friction coefficient μ can be lowered corresponding to the belt side surface angle θ. Therefore, even if the belt B is wound around the pulley P and the resin portion 16 of the block 7 is compressed at the contact portion 11 due to the pushing force and the shearing force from each tension band 1, the biting into the pulley groove of the block 7 does not occur. , When the block 7 subsequently comes out of the pulley groove, the block 7 does not remain stretched inside the pulley groove, and the block 7 can be smoothly separated from the pulley groove without pulling out by the tension band 1,
Fatigue failure of the tension band 1 can be suppressed to prevent early failure.

Therefore, while increasing the transmission load of the belt B, the blocks 7 can be smoothly pulled out from the pulley groove to prevent the tension band 1 from being cut early and the life of the belt B can be extended.

(Embodiment 2) FIGS. 4 and 5 show Embodiment 2 of the present invention (in each of the following embodiments, the same parts as those in FIGS. However, the shapes of the upper beam portions 13 and 13 are changed.

That is, in this embodiment, each upper beam portion 1 of the reinforcing member 12 embedded in each block 7 is
3 itself is bent, the base end portion and the left and right intermediate portions are inclined toward the tip end side toward the lower side, and the middle portion to the tip end portion extend in a substantially horizontal left and right direction. When viewed from the upper beam portions 13 as a whole, only the periphery of the left and right central portions has a mountain shape that is bent so as to partially project upward from both end portions.

Each of the upper beam portions 13 is located closer to the pulley center than the contact position between the upper and lower center lines L1 on the base end side, that is, the portion from the base end to the left and right intermediate portions, and the upper contact portion 11 of the block 7. The beam angle α1 formed with the pulley groove surface P1 is 90 ° or more (α1 ≧ 90 °) as in the first embodiment, but the vertical centerline L2 of the tip side, that is, the portion from the intermediate portion to the tip portion And the beam angle α2 formed by the pulley groove surface P1 closer to the pulley center than the contact position of the upper contact portion 11 of the block 7 is smaller than 90 ° (α2 <90 °).

As in the first embodiment, the coefficient of friction μ between each contact portion 11 of the block 7 and the pulley groove surface P1.
Is set to μ ≦ tan θ + 0.05 with respect to the belt side surface angle θ, and the friction coefficient μ is lowered corresponding to the belt side surface angle θ. Others are the same as those in the first embodiment.

Therefore, in this case, the vertical center line L2 on the tip end side of each upper beam portion 13 of the reinforcing member 12 and the pulley groove surface P1 closer to the pulley center than the contact position of the upper contact portion 11 of the block 7 are formed. Since the beam angle α2 is smaller than 90 °, the height of the block 7 can be reduced. That is, if the beam angle α is 90 ° or more over the entire upper beam portions 13 and 13 as in the first embodiment, in order to secure the fitting groove 8 on the side surface of the block 7,
The height of the block 7 increases. On the other hand, in the second embodiment, the vertical center line L1 only on the base end side of the upper beam portion 13 and the pulley groove surface P1 closer to the pulley center than the contact position of the upper contact portion 11 of the block 7 are formed. Since the beam angle α1 is 90 ° or more, the height of the block 7 can be reduced by the extent that the range of the beam angle is partially limited. This makes the block 7 smaller and lighter,
Vibration of block 7 and belt B when belt B is running
The centrifugal tension of the belt B can be reduced, and the tension band 1 can be prevented from being cut early due to heat generation or wear, so that the belt B can have a long life. Therefore, it is possible to balance the increase in the life of the belt B and the increase in the transmission load, and make them compatible with each other.

Further, the coefficient of friction μ between each contact portion 11 of the block 7 and the pulley groove surface P1 decreases corresponding to the belt side surface angle θ, and when each block 7 comes out of the pulley groove, the block 7 Can be separated from the pulley groove without the need for pulling out by the tension band 1, so that the belt B
It is possible to prevent the early breaking of the tension band 1 and increase the service life of the belt B while increasing the transmission load of.

(Third Embodiment) FIG. 6 shows a third embodiment,
The reinforcing member 12 in each block 7 as in the first embodiment.
In addition to the configuration in which each of the upper beam portions 13 and 13 of FIG. 2 is inclined to make the beam angle α with the pulley groove surface P1 be 90 ° or more, each of the lower beam portions 14 and 14 of the reinforcing member 12 is also inclined. The position of the tip end of the vertical center line L3 of each lower beam part 14 is located below the base end part.

As in the first embodiment, the coefficient of friction μ between each contact portion 11 of the block 7 and the pulley groove surface P1.
Is μ ≦ tan θ + 0.05 with respect to the belt side surface angle θ. Other configurations are similar to those of the first embodiment.

According to the third embodiment, the above-mentioned first embodiment
Similarly, it is possible to suppress the action of large tensile stress on the root portion 13a of each upper beam portion 13 of the reinforcing member 12 and prevent the fatigue fracture of the root portion 13a. Further, the friction coefficient μ between the contact portion 11 of the block 7 and the pulley groove surface P1 is low corresponding to the belt side surface angle θ, and when the block 7 of the belt B comes out of the pulley groove, the block 7 is tensioned. It can be separated from the pulley groove without the need to pull out by 1.

In addition to this, the tensile stress to the root portion 14a of the lower beam portion 14 of the reinforcing member 12 is also reduced for the same reason, and the fatigue fracture of the root portion 14a of the lower beam portion 14 is prevented. be able to. Therefore, the transmission load of the belt B can be further increased.

(Fourth Embodiment) FIG. 7 shows a fourth embodiment.
In the above-described first to third embodiments, the substantially H-shaped reinforcing member 12 is embedded in the block 7, but in this embodiment, the reinforcing member 12 includes one upper and lower beam portion 13, 14.
And a pillar portion 15 that connects the base end portions of the two beam portions 13 and 14 to each other, and has a substantially U shape. Further, the fitting groove 8 is formed only on one side surface of each block 7, and one tension band 1 is located in the fitting groove 8 substantially at the center portion in the belt width direction (substantially right and left central portion of the block 7). Are fitted together. There is no fitting groove 8 on the other side surface of the block 7, and the entire side surface is a contact portion 11 with the pulley groove surface P1.

The beam angle α of the upper beam portion 13 of the reinforcing member 12 (the vertical center line L of the upper beam portion 13)
And an angle formed by the pulley groove surface P1 on the pulley center side with respect to the contact position of the upper contact portion 11 of the block 7) is 90 ° or more. The other configurations are the same as those of the first embodiment, and therefore, the fourth embodiment can also achieve the same effects as the first embodiment.

The beam angles α and α1 in the first to fourth embodiments may be 90 ° or more, but the beam angle is 11
At 0 ° or more, the root portion 13a of the upper beam portion 13
Since there is no large decrease in tensile stress acting on
The maximum limit of the beam angle α is preferably 110 ° to 115 °.

Further, in the above-described first to fourth embodiments, the upper beam portion 13 of the reinforcing member 12 has a linear shape or a bent shape in combination thereof, but it may have a curved shape. In that case, the angle formed by the tangent line at each part of the vertical center line and the pulley groove surface P1 is defined as the beam angle α, and the beam angle α may be 90 ° or more.

[0048]

[0049]

In each of the above-mentioned embodiments, the upper recesses 2, 2, ... And the lower recesses 3, 3, ... Are provided on the upper and lower surfaces of the tension band 1, and the upper protrusions 9 and the lower protrusions are provided on each block 7 side. Although the portions 10 are formed respectively, the relationship between these concave portions and convex portions may be appropriately changed between the tension band 1 and each block 7, and for example, convex portions as meshed portions may be provided on the upper and lower surfaces of the tension band 1. Further, it is also possible to form a recess as an engaging portion in each block 7, respectively.

[0051]

EXAMPLE Next, a concrete example will be described. Like the structure of the fourth embodiment, a reinforcing member having an upper beam portion curved in an arch shape is held in a block, and a belt side surface angle is set. θ (angle of block side) is θ = 1
Examples 1 to 3 and Comparative Examples were manufactured by changing the friction coefficient μ between the left and right contact portions of the block and the pulley groove surface with respect to the block belt having 3 ° (tan θ = 0.23). The belt of each example was wound around a pulley to apply tension, and then the belt tension was removed to confirm whether or not the belt was bite into the pulley groove. The results are shown in Table 1. Table 1
In the evaluation of the detachability of the belt from the pulley groove, the symbol “◎” means that the belt came out of the pulley groove without resistance after the tension was removed, and “○” means that the belt was slightly removed from the pulley groove after the tension was removed. It means that the belt is pulled out only by the resistance of “1”, and “X” means that the belt bites into the pulley groove after the tension is removed.

[0052]

[Table 1]

According to the results shown in Table 1, the friction coefficient μ between the contact portion of the block and the pulley groove surface is the belt side surface angle θ.
On the other hand, in the comparative example of μ = 0.40 where μ> tan θ + 0.05, “×” indicates that the belt is not easily pulled out, whereas μ ≦.
tan θ + 0.05 (μ ≦ 0.28) μ = 0.2
In Examples 1 to 3 of 0, 0.23, and 0.25, all of the results were “⊚” or “∘”, and the belt detachability was good. From this, it was confirmed that by setting μ ≦ tan θ + 0.05, good detachability from the pulley groove of the belt can be secured.

[0054]

As described above, according to the first aspect of the present invention, the block type high-height block in which a large number of blocks are engaged with and fixed to the tension bands by fitting the tension bands into the fitting grooves on the side surfaces of each block. With respect to the load transmission V-belt, a substantially straight plate-shaped upper beam that is above the fitting groove of the reinforcing member embedded in the block and is inclined downward from the base end toward the tip. The beam angle between the vertical center line of the block and the pulley groove surface closer to the pulley center than the contact position of the upper contact portion on the upper side of the fitting groove on the block side surface is 90 ° or more, and the block contact portion and the pulley groove surface Coefficient of friction between
Was set to μ ≦ tan θ + 0.05 with respect to the belt side surface angle θ. Further, in the invention of claim 2, the upper beam portion of the reinforcing member in the block is a base end portion side that inclines downward toward the distal end side from the base end portion to the middle portion, From the end to the tip, bend it in the middle so that it is on the tip side that extends approximately in the belt width direction. Pulley on the pulley center side from the contact position between the vertical center line on the base end side and the upper contact part of the block The beam angle formed with the groove surface is 90 ° or more, and the beam angle formed with the pulley groove surface closer to the pulley center than the contact position of the vertical center line on the tip end side and the upper contact portion of the block is smaller than 90 °. The friction coefficient μ between the contact portion of the block and the pulley groove surface was set to μ ≦ tan θ + 0.05 .

Therefore, according to these inventions, the coefficient of friction μ between the contact portion of the block and the pulley groove surface is lowered so that the block remains in the pulley groove when the belt is wound around the pulley and then separated. By preventing the block from pulling out from the pulley groove without pulling it out with the tension band, fatigue failure of the tension band can be suppressed, thus premature cutting of the tension band is prevented while increasing the transmission load of the belt and the long life of the belt. Can be realized.

According to the third aspect of the present invention, since the position of the tip of the center line of the lower beam in the reinforcing member is located below the base end, the root portion of the lower beam of the reinforcing member is located. It is possible to reduce the tensile stress with respect to and prevent fatigue fracture of the root portion of the lower beam portion, and it is possible to further increase the transmission load of the belt.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a high load transmission V-belt according to a first embodiment of the present invention.

FIG. 2 is an enlarged side view of a high load transmission V-belt.

FIG. 3 is a perspective view of a V-belt for high load transmission.

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 2 showing a second embodiment.

FIG. 6 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention .

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Laid-Open No. 1-153839 (JP, A) Japanese Patent Laid-Open No. 5-196093 (JP, A) Japanese Patent Laid-Open No. 60-49151 (JP, A) 3692 (JP, U) Actual development 5-77650 (JP, U) Actual development 3-55942 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16G 1/00-17 / 00

Claims (3)

(57) [Claims] 1. A tension band in which a large number of upper meshed portions and lower meshed portions which are respectively aligned in the belt length direction are provided on the upper and lower surfaces so as to correspond to each other, and on the side surface in the belt width direction and on the upper wall surface. A fitting groove having an upper meshing portion that meshes with the upper meshing portion of the tension band, and a lower meshing portion that meshes with the lower meshing portion of the tension band on the lower wall surface, and both upper and lower sides of the mating groove. And a plurality of blocks provided with upper and lower contact portions that come into contact with the pulley groove surface and are fitted to the fitting grooves of the blocks by the tension bands. Each block includes a reinforcing member embedded in a resin portion such that at least the upper and lower meshing portions and contact portions are formed of the resin portion. Upper and lower beam portions respectively located on the side, and the upper and lower beam portions Is a V-belt for high-load transmission, comprising a pillar portion connecting the base end portions of the above, and the upper beam portion of the reinforcing member is inclined substantially downward from the base end portion toward the tip end portion. A straight plate-shaped member, and the beam angle formed by the vertical center line of the upper beam portion and the pulley groove surface closer to the pulley center than the contact position of the upper contact portion on the side surface of the block is 90 ° or more. Coefficient of friction between block contact part and pulley groove surface μ
Is a belt side surface angle θ formed by the left and right side surfaces of the belt and a plane in the vertical direction, μ ≦ tan θ + 0.05. 2. A tension band in which a large number of upper meshed portions and lower meshed portions which are respectively arranged in the belt length direction on the upper and lower surfaces are provided in a vertically corresponding manner, and a side surface in the belt width direction and an upper wall surface. A fitting groove having an upper meshing portion that meshes with the upper meshing portion of the tension band, and a lower meshing portion that meshes with the lower meshing portion of the tension band on the lower wall surface, and both upper and lower sides of the mating groove. And a plurality of blocks provided with upper and lower contact portions that come into contact with the pulley groove surface and are fitted to the fitting grooves of the blocks by the tension bands. Each block includes a reinforcing member embedded in a resin portion such that at least the upper and lower engaging portions and contact portions are formed of the resin portion. Upper and lower beam portions respectively located on the side, and the upper and lower beam portions A V-belt for high load transmission, comprising a pillar portion connecting the base end portions of the above, and the upper beam portion of the reinforcing member is bent at the middle portion, and the base end portion to the middle portion is directed toward the tip end side. And the base end portion is inclined toward the lower side, and the intermediate portion to the tip end portion is the tip end portion side extending substantially in the belt width direction. The base end portion of the upper beam portion of the reinforcing member is The beam angle between the vertical center line on the side of the block and the pulley groove surface on the pulley center side of the contact position of the upper contact portion on the side of the block is 90 ° or more, while the vertical center line on the tip side and the side of the block are The beam angle formed by the pulley groove surface on the pulley center side of the contact position of the upper contact portion is smaller than 90 °, and the friction coefficient μ between the contact portion of the block and the pulley groove surface is μ.
Is a belt side surface angle θ formed by the left and right side surfaces of the belt and a plane in the vertical direction, μ ≦ tan θ + 0.05. 3. The V-belt for high load transmission according to claim 1 or 2 , wherein the tip of the vertical center line of the lower beam portion of the reinforcing member is located below the base end. A characteristic V-belt for high load transmission.