JP5325889B2 - V belt for high load transmission - Google Patents

Description

  The present invention relates to a V-belt for high load transmission.

  Conventionally, a high load transmission V-belt is wound around a plurality of V pulleys including a variable pulley having a variable groove interval and used in a belt type continuously variable transmission such as an automobile. This high load transmission V-belt is configured to receive the side pressure from the groove surface of each pulley at each block, transfer power between each pulley and each block, and transmit power by each tension band. (For example, refer to Patent Document 1).

11, a conventional high-load drive V-belt 100 is a longitudinal sectional view schematically showing.

  As shown in FIG. 11, the high load transmission V-belt 100 has a pair of tension bands 101 formed in an annular shape so as to extend parallel to each other in the belt length direction, and has a total length with respect to the pair of tension bands 101. A plurality of blocks 102 are provided so as to be aligned with each other at a predetermined pitch.

  Each block 102 has a pair of notched groove-like fitting portions 103 opened to the outside in the belt width direction on both sides, and a tension band 101 is fitted to each fitting portion 103. Each of these blocks 102 is embedded with a metal reinforcing member 104 in the backbone so that it can withstand a relatively large lateral pressure received from the pulley, and this reinforcing member 104 is covered with a resin such as a phenol-based composite resin. The contact portion 105 that contacts the groove surface of the pulley is made of a resin having a uniform thickness.

Japanese Patent No. 3044212

Figure 12 is a longitudinal sectional view schematically showing a conventional high-load drive V-belt 100 during traveling.

  As shown in FIG. 12, the high load transmission V-belt 100 has a side pressure from the pulley 106 applied to each block 102 when the groove interval of the V-pulley is narrowed during traveling, particularly when shifting. The contact portion 105 is easily deformed so as to bend outward of the belt. Here, a two-dot chain line in FIG. 12 indicates the block 102 in a state where the contact portion 105 is not bent. Further, a curve 107 in FIG. 12 shows a distribution of the side pressure that the contact portion 105 receives from the pulley 106, and the side pressure in the portion increases as the curve 107 moves away from the groove surface of the pulley 106 in the vertical direction. It shows that. As described above, since the contact portion 105 bends to the outside of the belt, the side pressure received by the contact portion 105 from the pulley 106 increases toward the inside of the belt, so that the contact portion 105 is made of resin having a uniform thickness as described above. When configured, the side pressure received by the contact portion 105 tends to increase locally inside the belt. For this reason, there is a problem that the contact portion 105 is broken by the locally large side pressure from the pulley 106 and the block 102 is easily damaged.

  This invention is made | formed in view of such a point, The place made into the objective is to suppress the failure | damage of the contact part which contacts the V pulley in each block.

To achieve the above object, in this invention, the resin contact portion for contacting the groove surface of the V-pulley of the block, and increase the coating thickness for the reinforcing member of the block toward the belt inner side.

Specifically, the onset Ming, a tension band which is formed into an annular shape so as to extend in the longitudinal direction of the belt, and a plurality of blocks mounted so as to be aligned with each other along the longitudinal direction of the belt to the tension band Each of the blocks includes a reinforcing member that reinforces the block body, and a resin contact portion that is provided so as to cover at least a part of the side surface of the reinforcing member and contacts the groove surface of the V pulley. The following solution is taken for the load transmission V-belt .

That is, the high load transmission V-belt according to the present invention is formed so that the covering thickness of the reinforcing member in the contact portion increases toward the belt inner side, and the groove surface of the V pulley in the contact portion. The angle formed between the contact surface that contacts the surface and the side surface of the reinforcing member on which the contact portion is provided is 8 degrees or more and 20 degrees or less .

  In the high load transmission V-belt having the above-described configuration, the tension band is provided in a pair so as to extend in parallel with each other, and the reinforcing member includes a pair of beam portions provided so as to sandwich the pair of tension bands, and A pillar portion provided between a pair of tension bands and connecting the pair of beam portions to each other, and a coating thickness of the contact portion provided on at least one of the pair of beam portions is directed toward the inner side of the belt. May be larger.

In such a configuration, it is preferable that the coating thickness of the contact portion provided on both of the pair of beam portions increases toward the belt inner side.

The pair of tension bands are arranged in the belt width direction, and the pair of beam portions constituting the reinforcing member extend in the belt width direction, and are provided so as to sandwich the pair of tension bands in the belt thickness direction. May be.

In such a configuration, the surface corresponding to the tension band in each beam portion extends in parallel with the tension band in the belt width direction, and the reinforcing member has a surface located on the tension band side of each beam portion. Is provided with a uniform covering thickness so as to contact the tension band and to cover both side surfaces of each beam portion in the belt width direction. It is preferable that it is composed of portions covering both side surfaces in the belt width direction.

Furthermore, it is preferable that the coating thickness of a portion covering the surface of the resin portion located on the tension band side of the beam portion is thinner than the coating thickness that increases toward the belt inside of the contact portion.

-Action-
Next, the operation of the present invention will be described.

  According to the V-belt for high load transmission according to the present invention, the resin contact portion that is provided so as to cover at least a part of the reinforcing member that reinforces each block and contacts the groove surface of the V pulley is covered with the reinforcing member. The thickness is formed so as to increase toward the inside of the belt. As a result, the buffering performance against the side pressure from the V pulley at the contact portion itself increases toward the inside of the belt, and even if the contact portion is deformed to bend toward the outside of the belt while the belt is running, the side pressure received by the contact portion from the V pulley. Is greatly dispersed toward the inner side of the belt, so that the side pressure received by the contact portion on the inner side of the belt is suppressed from being locally increased. Therefore, the damage of the contact part in each block is suppressed.

  Furthermore, with the dispersion of the side pressure received by the contact portion from the V pulley, the shear force received by the contact portion from the V pulley is also dispersed and suppressed from increasing locally inside the belt, thereby preventing the contact portion from being inside the belt. The promotion of local wear is suppressed, and the wear life of the contact portion is improved.

  For example, a pair of tension bands are provided so as to extend in parallel with each other, and a reinforcing member is provided between a pair of beam portions provided so as to sandwich the pair of tension bands and a pair of beams. Even if the coating thickness of the contact portion provided on at least one of the pair of beam portions increases toward the inner side of the belt, the coating thickness is the inner side of the belt. The action and effect of the present invention are concretely exhibited at the contact portion that increases toward the surface.

  In particular, when the coating thickness of the contact portions provided on both of the pair of beam portions increases toward the inside of the belt, breakage of the contact portions provided on both of the pair of beam portions is suppressed. Therefore, breakage of each block is further suppressed as compared with the case where the coating thickness of only the contact portion provided on one of the pair of beam portions is increased toward the belt inner side.

  By the way, when the angle formed by the contact surface that contacts the groove surface of the V pulley in the contact portion and the side surface of the reinforcing member on which the contact portion is provided is smaller than 8 degrees, the cushioning property of the contact portion toward the belt inner side Is not easily increased, and the side pressure received by the contact portion from the V pulley is not sufficiently dispersed. For this reason, it is difficult to sufficiently increase the side pressure strength of the block. On the other hand, when the angle formed by the contact surface of the contact portion and the side surface of the reinforcing member is larger than 20 degrees, the mechanical strength of the contact portion is relatively low inside the belt, so that the belt travels under a high load condition. The durability strength of the block at this time is relatively low, and it acts on the contact surface during belt running, especially when an extremely high load is applied to the block, such as when starting belt running or running at low speed. There is a high possibility that the contact portion will break early in the belt due to the shearing force from the V pulley. That is, there is a possibility that the durability strength of the belt itself during traveling under a high load condition may be relatively reduced.

In contrast, in the high-load drive V-belt according to the present invention, since the angle and forms a side of the contact surface and the reinforcing member of the contact portion is less than and 20 degrees 8 degrees, the contact toward the belt inner side The buffering of the contact part is reliably and well enhanced, and the side pressure received by the contact part from the V pulley is sufficiently dispersed, so that the side pressure strength of the block is sufficiently increased, and the mechanical strength of the contact part is increased inside the belt. Is maintained at a relatively high level, the decrease in the durability of the block during belt running under a high load condition is relatively small. Thereby, damage of each block is suppressed favorably.

According to the present invention, the resin-made contact portion that is provided so as to cover at least a part of the side surface of the reinforcing member that reinforces each block and contacts the groove surface of the V pulley has a covering thickness of the reinforcing member. The angle formed by the contact surface that contacts the groove surface of the V pulley at the contact portion and the side surface of the reinforcing member on which the contact portion is provided is 8 degrees or more and 20 degrees or less. Since it exists , the damage of the contact part in each block can be suppressed. As a result, the life of the high load transmission V-belt can be extended.

FIG. 1 is a side view schematically showing a continuously variable transmission using the high load transmission V-belt of the first embodiment. Figure 2 is a longitudinal cross-sectional view schematically illustrating a part of a V-pulley constituting the continuously variable transmission. FIG. 3 is a perspective view schematically showing a part of the high load transmission V-belt of the first embodiment. 4 is a diagram schematically showing a cross section taken along line IV-IV in FIG. Figure 5 is a longitudinal cross-sectional view schematically showing a V-belt for high load transmission during traveling. FIG. 6 is a graph showing the relationship between the angle formed by the contact surface of the contact portion and the side surface (adhesion surface) of the reinforcing member and the side pressure strength ratio of the block. FIG. 7 is a cross-sectional view schematically showing a running test apparatus used in a high load durability test. FIG. 8 is a graph showing the relationship between the angle formed by the contact surface of the contact portion and the side surface (adhesion surface) of the reinforcing member and the high load durability strength ratio of the block. Figure 9 is a longitudinal sectional view showing a high-duty power transmission V-belt coating thickness of the contact portion is larger toward the belt inner side only by the inner beam portion in the other embodiment schematically. Figure 10 is a longitudinal cross-sectional view schematically showing a high-load drive V-belt coating thickness of the contact portion only the outer beam portion is greater toward the belt inner side in the other embodiments. Figure 11 is a longitudinal sectional view schematically showing a conventional high-load drive V-belt. 12 is a longitudinal sectional view schematically showing a conventional high-load drive V-belt during the running.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments.

Embodiment 1 of the Invention
1 to 8 show a first embodiment of a high load transmission V-belt according to the present invention.

FIG. 1 is a side view schematically showing a continuously variable transmission T in which a V belt B for high load transmission is used. Figure 2 is a longitudinal cross-sectional view schematically illustrating a part of the pulley 3 and 4 constituting the continuously variable transmission T of the state in which the high-load drive V-belt B is wound. FIG. 3 is a perspective view schematically showing a part of the high load transmission V-belt B of the first embodiment. Figure 4 is a longitudinal cross-sectional view schematically showing a high-load drive V-belt B along the line IV-IV of FIG. Figure 5 is a longitudinal sectional view schematically showing a high-load drive V-belt B in the belt run. 6-8 is a figure which shows the test apparatus and test result in the evaluation experiment of this embodiment so that it may mention later.

  A high-load transmission V-belt (hereinafter simply referred to as a V-belt) B according to this embodiment is used in a continuously variable transmission T that is a belt transmission, for example.

  As shown in FIG. 1, the continuously variable transmission T includes a drive shaft 1 and a driven shaft 2 arranged in parallel to the drive shaft 1, and a drive pulley 3 and a driven shaft are connected to the drive shaft 1 and the driven shaft 2. Each pulley 4 is attached. As shown in FIG. 2, the drive pulley 3 and the driven pulley 4 are integrally formed with the shafts 1 and 2 and fixed in the axial direction thereof, and supported so as to be slidable in the axial direction. And a movable sheave 6 that forms a belt groove with a V-shaped cross section through which the V-belt B enters and exits from the fixed sheave 5, and moves the movable sheave 6 toward or away from the fixed sheave 5. Thus, the groove interval can be changed.

  In this continuously variable transmission T, a belt V is wound around the belt groove between the sheaves 5 and 6 of the driving pulley 3 and the driven pulley 4 and the groove interval is changed to change the belt winding around the pulleys 3 and 4. The configuration is such that the hanging diameter can be adjusted, and the rotational force of the drive pulley 3 is transmitted to the driven pulley 4 via the V-belt B. The continuously variable transmission T shifts the belt winding diameters of the pulleys 3 and 4 in opposite directions, and changes the winding diameter of the driving pulley 3 to the winding diameter of the driven pulley 4 as shown in FIG. However, although it is not shown in the drawing, it is decelerated when the winding diameter of the driven pulley 4 is made larger than the winding diameter of the drive pulley 3. Between the driving pulley 3 and the driven pulley 4, a tensioner pulley 7 that is a flat pulley that presses the V belt B from the outside of the belt and applies tension to the V belt B is disposed.

  As shown in FIG. 3, the V-belt B has a pair of tension bands 10 formed in an annular shape so as to extend in parallel with each other in the belt length direction along with the belt width direction. And a plurality of blocks 20 attached to be aligned with each other.

  The pair of tension bands 10 includes a shape retaining layer 11 made of hard rubber, and a core wire 12 arranged in a spiral shape so as to extend in the belt length direction inside the shape retaining layer 11.

  The shape-retaining layer 11 is excellent in heat resistance and permanently deformed, for example, by mixing short fibers such as aramid short fibers and nylon short fibers with hydrogenated nitrile rubber (H-NBR) reinforced with zinc methacrylate. Hard rubber that is difficult is used. This hard rubber requires a rubber hardness of about 75 ° or more when measured with a JIS-C hardness meter. Canvas 13 is bonded to both sides of the shape retaining layer 11 for the purpose of improving wear resistance. Each of these canvases 13 is produced by impregnating a hydrogenated nitrile rubber (H-NBR) reinforced with zinc methacrylate into a nylon canvas, for example, and then vulcanizing the hydrogenated nitrile rubber.

  In each of these tension bands 10, a plurality of inner grooves 14 that are arranged at predetermined intervals in the belt length direction and extend in the belt width direction are formed on the inner side of the belt as inner meshed portions. A plurality of outer grooves 15 corresponding to 14 and extending in the belt width direction are formed outside the belt as outer meshed portions.

Each block 20 is formed a vertical cross-section along the belt width direction in a substantially Engineering-shape, a pair of beam portions 20a, 20b provided so as to sandwich the pair of tension bands 10 with each extending in the belt width direction, A pillar portion 20c is provided between the pair of tension bands 10 and connects the central portions in the belt width direction of the pair of beam portions 20a and 20b to each other.

  The inner beam portion 20a disposed on the inner side of the belt and the outer beam portion 20b disposed on the outer side of the belt constituting the pair of beam portions are gradually shortened in the belt width direction from the outer side of the belt toward the inner side of the belt. The angles formed by the contact surfaces 27a that contact the pulleys 3 and 4 on both sides in the belt width direction are substantially the same as the angles formed by the groove surfaces of the pulleys 3 and 4. On both sides of the pillar portion 20c in the belt width direction, a pair of notched groove-like fitting portions 21 that are opened to the outside in the belt width direction and into which the respective tension bands 10 are fitted are defined.

  Each fitting portion 21 of each block 20 is provided with an inner protrusion 22 projecting so as to be engaged with the inner groove 14 of the tension band 10 as an inner engagement portion on the inner side of the belt. An outer ridge portion 23 protruding so as to mesh with the groove 15 is provided on the belt outer side as an outer meshing portion. Since the inner ridges 22 and the outer ridges 23 are engaged with the inner grooves 14 and the outer grooves 15, the blocks 20 are respectively locked and fixed to the two tension bands 10 along the belt length direction. Thus, power is exchanged with these two tension bands 10.

  As shown in FIG. 4, each of these blocks 20 is configured such that a metal reinforcing member 25 that reinforces the block main body is embedded in the backbone portion, and this reinforcing member 25 is covered with a resin portion 26. 25 is provided so as to cover both side surfaces of the belt 25 in the belt width direction, and has resin contact portions 27 that come into contact with the groove surfaces of the pulleys 3 and 4.

  The reinforcing member 25 is formed of an aluminum alloy or the like in a substantially engineered shape having substantially the same contour shape as the block main body, and is a beam reinforcement that is a pair of beam portions that reinforce the beam portions 20a and 20b and the pillar portion 20c of the block main body. It is comprised by the part 25a, 25b and the pillar reinforcement part 25c which is a pillar part. That is, each beam part 20a, 20b is comprised by each beam reinforcement part 25a, 25b and resin part 26a, 26b which covers these each beam reinforcement part 25a, 25b, respectively, The pillar part 20c is the pillar reinforcement part 25c and its pillar reinforcement. It is comprised with the resin part 26c which covers the part 25c.

  The resin portion 26 is made of, for example, a phenol-based composite resin, and preferably has an elastic modulus at room temperature of about 9000 MPa or more from the viewpoint of efficiently receiving the rotational force from the pulleys 3 and 4. Each of these blocks 20 is formed, for example, by insert molding so that the reinforcing member 25 is embedded inside the resin portion 26 so as to be disposed at the central portion of the block 20.

  In the present embodiment, the reinforcing member 25 is covered with the resin portion 26 and each block 20 is configured. However, the reinforcing member 25 is configured so that at least the contact portion 27 and the fitting portion 21 are formed of resin. It is sufficient that the resin portion 26 is provided on the surface, and the reinforcing member 25 may be exposed on the surface of the block 20 in other portions.

  Each block 20 of the V-belt B in this embodiment is formed so that the covering thickness of the reinforcing member 25 in the contact portion 27 increases toward the belt inner side in both the pair of beam portions 20a and 20b. Yes.

  By the way, the contact surface 27a that contacts the groove surface of each pulley 3 and 4 in the contact portion 27, and the side surface of the reinforcing member 25 provided with the contact portion 27, that is, the adhesive surface 25d of the reinforcing member 25 with the contact portion 27 Is less than 8 degrees, it is difficult to satisfactorily improve the buffering property of the contact portion 27 toward the inner side of the belt, and the side pressure received by the contact portion 27 from the pulleys 3 and 4 is not easily dispersed. . For this reason, it is difficult to sufficiently increase the lateral pressure strength of the block 20. On the other hand, when the angle α formed by the contact surface 27a of the contact portion 27 and the adhesive surface 25d of the reinforcing member 25 is larger than 20 degrees, the mechanical strength of the contact portion 27 is relatively low inside the belt. The durability strength of the block 20 in the belt running under a high load condition is relatively greatly reduced, and an extremely high load is applied to the V-belt B during the belt running, particularly at the start of the belt running or during the low-speed belt running. When added, there is a high possibility that the contact portion 27 breaks inside the belt due to the shearing force from the pulleys 3 and 4 acting on the contact surface 27a. That is, there is a possibility that the durability strength of the V-belt B during traveling under a high load condition may be relatively reduced.

  From this, in each block 20 of the present embodiment, the angle α formed by the contact surface 27a of the contact portion 27 and the adhesive surface 25d of the reinforcing member 25 is 8 degrees or more and 20 degrees or less.

  Further, as shown in FIG. 3, the longitudinal section along the belt length direction is tapered so that the lower half of the belt inner side in each block 20 gradually decreases in the belt length direction toward the belt inner side. And is wound around the pulleys 3 and 4 in a positive bending state. On the other hand, the upper half of the belt outer side in each block 20 is formed with a taper in the longitudinal section along the belt length direction so that the thickness in the belt length direction gradually decreases toward the belt outer side, and the tensioner pulley 7 is configured to be able to be in a reverse bending state by abutting on the belt outer surface.

  As described above, in the continuously variable transmission T, the V-belt B receives the side pressure from the groove surface of each pulley 3, 4 at each block 20, and the power is transmitted between each pulley 3, 4 and each block 20. While performing transmission and reception, it is comprised so that power transmission may be performed by each tension belt | band | zone 10. FIG.

-Evaluation experiment-
Next, a specific evaluation experiment will be described. As an evaluation experiment, for the blocks constituting the V-belt, a side pressure strength evaluation experiment for evaluating the side pressure strength and a high load endurance strength evaluation experiment for evaluating the endurance strength in belt running under high load conditions are performed. went.

(Side pressure strength evaluation experiment)
In the side pressure strength evaluation experiment, the side pressure strength ratio of the V belt block 20 according to the present invention including the V belt B block 20 having the same configuration as that of the first embodiment is limited to that of the V belt block having the conventional configuration. It was obtained by analysis using the element method.

  In this evaluation experiment, as Examples 1 to 5, the angles α formed by the contact surface 27a of the contact portion 27 and the adhesive surface 25d of the reinforcing member 25 are 7.5 degrees, 8.4 degrees, and 15.7 degrees, respectively. Analysis was performed on five blocks 20 at 20.0 degrees and 22.1 degrees. Further, as a comparative example, the angle formed by the contact surface of the contact portion and the adhesion surface of the reinforcing member is 0.0 degrees, that is, the block having the conventional configuration in which the contact portion is formed with a uniform thickness is similarly applied. Analysis was performed. The analysis models of the blocks of Examples 1 to 5 and the comparative example are all the same except for the angle formed by the contact surface of the contact portion and the bonding surface of the reinforcing member.

  In this evaluation experiment, for each block of the example and the comparative example, a constant side pressure is applied to the contact portion, and the side pressure strength is obtained based on the maximum value of the stress generated in the contact portion due to the side pressure. The side pressure intensity ratio of each block 20 of the example with respect to the block of the comparative example was obtained using the maximum value of the stress obtained for the example block as a reference value.

  The analysis results are shown in Table 1 and FIG. FIG. 6 is a graph showing the relationship between the angle formed by the contact surface of the contact portion and the adhesion surface of the reinforcing member and the lateral pressure strength ratio.

  As shown in Table 1 and FIG. 6, each of the blocks 20 of Examples 1 to 5 has higher lateral pressure strength than the block of the comparative example, and the contact surface 27 a of the contact portion 27 and the reinforcing member 25 are bonded. It was confirmed that the lateral pressure strength was increased by forming an angle with the surface 25d. Therefore, the block 20 is formed so that the covering thickness of the reinforcing member 25 in the contact portion 27 increases toward the belt inner side, so that the contact portion has a uniform covering thickness. In comparison, it has been found that there is an advantageous effect of increasing the lateral pressure strength of the block 20.

  Further, from the analysis result shown in FIG. 6, when the angle α formed by the contact surface 27a of the contact portion 27 and the adhesive surface 25d of the reinforcing member 25 is 8 degrees or more, the lateral pressure strength is higher than the block having the conventional configuration. It was found that it was certainly increased to 1.1 times or more.

(High load durability test)
In the high load endurance strength evaluation experiment, each V belt having the blocks of Examples 1 to 5 and the comparative example used as analysis models in the side pressure strength evaluation experiment was prepared, and each V belt was used as a belt type of an automobile The high load endurance strength of each of the blocks of Examples 1 to 5 and the comparative example is obtained by performing test running under the same belt running conditions as in the mode from the start of the automobile to the low speed running when used in a continuously variable transmission. evaluated.

  As shown in FIG. 7, this high load durability test is performed by using a running test apparatus in which a driving pulley 41 having a pulley diameter of 70 mm and a driven pulley 42 having a pulley diameter of 127 mm are arranged in a box 40. Used.

  Specifically, each V-belt having the blocks of Examples 1 to 5 and the comparative example is manufactured to a circumferential length of 612 mm, each V-belt is wound around the driving pulley 41 and the driven pulley 42, and the box 40 The drive pulley 41 is driven at a torque of 53.9 N · m so that the rotational speed is 2600 rpm while maintaining the internal temperature of the cylinder at about 90 ° C. and applying a shaft load (DW) of 3285.2 N to the driven pulley 42. Thus, each V-belt was run under low-speed and high-load conditions until the block was damaged. Then, the time required until the breakage is obtained as the high load endurance strength of each block, and the high load endurance of each block 20 of the embodiment for the comparative example is based on the high load endurance strength obtained for the block of the comparative example. The intensity ratio was determined.

  The results of this evaluation experiment are shown in Table 1 and FIG. FIG. 8 is a graph showing the relationship between the angle formed by the contact surface of the contact portion and the adhesive surface of the reinforcing member and the high load durability strength ratio.

  As shown in Table 1 and FIG. 8, each block 20 of Examples 1 to 4 has a high load durability greater than 0.90 times that of the block of the comparative example, and is slightly high load durability. Although reduced in strength, it was confirmed that the high load endurance strength of the block 20 of Example 5 was reduced to nearly 0.8 times that of the block of the comparative example. From the results shown in FIG. 8, when the angle α formed by the contact surface 27 a of the contact portion 27 and the adhesive surface 25 d of the reinforcing member 25 is 20 degrees or less, the block having the conventional configuration has a high load durability. It has been found that the strength is kept larger than 0.9 times and can be suppressed to a relatively small decrease.

  From each evaluation experiment described above, the angle α formed by the contact surface 27a of the contact portion 27 and the adhesive surface 25d of the reinforcing member 25 is 8 degrees or more and 20 degrees or less. The lateral pressure strength of the block 20 is reliably increased to a relatively large value of 1.1 times or more, and the high load endurance strength of the block 20 is maintained to be larger than 0.9 times and can be suppressed to a relatively small decrease. did.

-Effect of Embodiment 1-
Therefore, according to the first embodiment, both the pair of beam portions 20a and 20b are provided so as to cover both side surfaces of the reinforcing member 25 that reinforces each block 20, and contacts the groove surfaces of the pulleys 3 and 4. The resin contact portion 27 is formed so that the covering thickness of the reinforcing member 25 increases toward the belt inner side. As a result, the buffering property of the contact portion 27 itself can be increased toward the inner side of the belt. As shown in FIG. 5, even if the contact portion 27 is deformed to bend toward the outer side of the belt while the belt is running, The side pressure received from the pulleys 3 and 4 can be greatly dispersed toward the inside of the belt. Here, a chain double-dashed line in the drawing indicates the block 20 in a state where the contact portion 27 is not bent. Further, a curve 31 in the figure shows a distribution of the side pressure received by the contact portion 27 from the pulleys 3 and 4, and the side pressure at that portion increases as the curve 31 is separated from the groove surface of the pulleys 3 and 4 in the vertical direction. Indicates that it is growing. As described above, the side pressure received by the contact portion 27 can be greatly dispersed toward the inner side of the belt, so that the side pressure received by the contact portion 27 on the inner side of the belt can be suppressed from being locally increased. Therefore, damage to the contact portion 27 in both the pair of beam portions 20a and 20b in each block 20 can be suppressed.

  In addition to this, with the dispersion of the side pressure received by the contact portion 27 from each pulley 3, 4, the shear force received by the contact portion 27 from each pulley 3, 4 is also dispersed and suppressed from locally increasing inside the belt. By being able to do, promotion of local wear inside the belt in contact part 27 can be controlled, and the wear-resistant life of contact part 27 can be improved.

  Furthermore, the angle α formed by the contact surface 27a that contacts the groove surface of each pulley 3 and 4 in the contact portion 27 and the adhesive surface (side surface) 25d provided with the contact portion 27 in the reinforcing member 25 is 8 degrees or more and 20 degrees. As described below, the above-described side pressure strength evaluation experiment shows that the side pressure received by the contact portions 27 from the pulleys 3 and 4 can be sufficiently dispersed by reliably and satisfactorily increasing the buffering properties of the contact portions 27 toward the belt inner side. As described above, the side load strength of each block 20 can be sufficiently increased, and the mechanical strength of the contact portion 27 can be kept relatively high even on the inner side of the belt. In addition, the decrease in the durability of each block 20 during belt running under a high load condition can be made relatively small. Thereby, the damage of each block 20 can be suppressed favorably. As a result, the life of the high load transmission V-belt B can be extended.

<< Other Embodiments >>
In the first embodiment, the coating thickness of the contact portion 27 is increased toward the inner side of the belt in both the pair of beam portions 20a and 20b. However, the present invention is not limited to this, and as shown in FIG. Further, the coating thickness of the contact portion 27 may be increased toward the inside of the belt only by the inner beam portion 20a, and the coating thickness of the contact portion 27 may be increased by the inner side of the belt only by the outer beam portion 20b as shown in FIG. It may be bigger toward you. Thus, if the coating thickness of the contact portion 27 increases toward the belt inner side in one of the pair of beam portions 20a and 20b, the coating thickness of the contact portion 27 increases toward the belt inner side. It becomes possible to suppress damage.

  In the first embodiment, the angle α formed by the contact surface 27a that contacts the groove surface of the pulleys 3 and 4 in the contact portion 27 and the adhesive surface (side surface) 25a provided with the contact portion 27 in the reinforcing member 25 is 8 degrees or more. However, the present invention is not limited to this, and the angle formed by the contact surface 27a of the contact portion 27 and the adhesive surface 25d of the reinforcing member 25 may be smaller than 8 degrees. It may be larger than the degree.

  In the first embodiment, the case where the V belt B is used for the continuously variable transmission T as the belt transmission device has been described. However, the present invention is not limited to this, and the V belt B can be used for other belt transmission devices. It is possible to apply.

  As described above, the present invention is useful for a high load transmission V-belt, and particularly for a high load transmission V-belt that is desired to suppress damage to a contact portion that contacts a V pulley in each block. Is suitable.

B V-belt for high load transmission 3 Drive pulley (V pulley)
4 Driven pulley (V pulley)
10 Tension band 20 Block 25 Reinforcement member 25a, 25b Beam reinforcement part (beam part)
25c Pillar reinforcement (pillar)
25d Adhesive surface of reinforcing member (side surface provided with contact portion)
27 Contact part 27a Contact surface

Claims (5)

A tension band formed in an annular shape so as to extend in the belt length direction;
A plurality of blocks attached to the tension belt so as to be aligned with each other along the belt length direction,
Each of the blocks includes a reinforcing member that reinforces the block main body, and a high load transmission that includes a resin contact portion that is provided so as to cover at least a part of the side surface of the reinforcing member and contacts the groove surface of the V pulley. V belt for
The contact portion is formed such that the covering thickness of the reinforcing member increases toward the belt inner side ,
The angle formed by the contact surface that contacts the groove surface of the V pulley in the contact portion and the side surface of the reinforcing member on which the contact portion is provided is 8 degrees or more and 20 degrees or less. V-belt for high load transmission. In the V belt for high load transmission according to claim 1,
A pair of tension bands extending in parallel to each other;
The reinforcing member is composed of a pair of beam portions provided so as to sandwich the pair of tension bands, and a pillar portion provided between the pair of tension bands and connecting the pair of beam portions to each other,
A high load transmission V-belt characterized in that a coating thickness of the contact portion provided on at least one of the pair of beam portions increases toward the inside of the belt. The high load transmission V-belt according to claim 2,
A high-load transmission V-belt characterized in that a coating thickness of the contact portion provided on both of the pair of beam portions increases toward the inside of the belt. The high load transmission V-belt according to claim 2 or 3,
The pair of tension bands are aligned in the belt width direction,
The pair of beam portions constituting the reinforcing member extend in the belt width direction, and are provided so as to sandwich the pair of tension bands in the belt thickness direction.
A surface corresponding to the tension band in each beam portion extends in parallel with the tension band in the belt width direction,
The reinforcing member includes a resin portion that covers a surface of each beam portion that is located on the tension band side with a uniform coating thickness, contacts the tension band, and covers both side surfaces of each beam portion in the belt width direction. Provided,
The contact portion is configured by a portion of the resin portion that covers both side surfaces of the beam portions in the belt width direction.
A V-belt for high load transmission characterized by the above. The high load transmission V-belt according to claim 4,
The coating thickness of the resin portion covering the surface located on the tension band side of the beam portion is thinner than the coating thickness increasing toward the belt inside of the contact portion.
A V-belt for high load transmission characterized by the above.

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