JPH037632Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a high-load power transmission device consisting of an endless tension band and a plurality of blocks having grooves in which the tension band is removably fitted in the width direction. This invention relates to a V-belt for use.

(Prior Technology) Currently, gear-type or hydraulic-type transmissions are used in automobiles, combine harvesters, tractors, etc., but in recent years, belt-type continuously variable transmissions have been developed for the purpose of improving operability and fuel efficiency. Development of the device is underway.

The belt used in this belt-type continuously variable transmission requires an extremely high torque transmission ability, and conventional rubber V-belts cannot withstand high lateral pressure and buckle, making them unusable.

Therefore, various high-load transmission belts have been proposed in the past (for example, JP-A-46-4861, JP-A-55-27595, JP-A-56-76745, JP-A-59). -77147 publication, JP 60-49151
(see publication).

Furthermore, as described in Japanese Patent Application Laid-Open No. 60-49151, the applicant has also proposed a V-belt constructed by locking a plurality of blocks to a pair of endless tension bands by engaging a concave portion and a convex portion. is proposed.

As is well known, the speed change pulley around which such a V-belt is wound consists of a movable sheave and a fixed sheave in the shape of a truncated cone with the same angle. When block 101, which is engaged with When S coincides with the radial direction R of the speed change pulley 102), no gap is created between the side surfaces 101a, 101b of the block 101 and the pulley groove surfaces 102a, 102b (see FIG. 3b). Note that W is the center line of the core of the tension band.

(Problem to be solved by the invention) By the way, in the V-belt as described above,
The block 101 has a shape in which the upper width is large and the lower width is small because it is necessary to engage the pulley. Therefore, if the blocks 101 are made of materials with the same specific gravity, the center of gravity of the block 101 will be at the tension band. Usually, the center of gravity is located above the center body, and if a reinforcing member or the like having a different specific gravity is buried inside, the position of the center of gravity changes depending on the reinforcing member or the like.

Therefore, when the center of gravity of the block 101 is located below the central body of the tension band, the air resistance that the block 101 receives in the straight running state before engaging the pulley causes the block 101 to move as shown in FIG. 4a. , the upper part of the block 101 is inclined toward the pulley rotation direction T, and in this state it comes to engage with the pulley groove surfaces 102a and 102b of the speed change pulley 102. In that case, the pulley groove surfaces 102a and 102b of the speed change pulley 102 have a hyperbolic shape and the pulley angle is smaller than the angle formed by both side surfaces 101a and 101b of the block 101, so that only the upper end of the block 101 has the pulley groove surface 102a. ,10
2b (see FIG. 4b).

Therefore, the block 101 is connected to the speed change pulley 102.
While engaged with the pulley groove surfaces 102a, 102b, the contact point _P1 between the block 101 and the pulley groove surfaces 102a, 102b, which is formed at the upper end of the block 101, is used as a fulcrum, and the point of effort is placed on the groove in which the tension band fits. As a result, the block 101 swings.

As shown in FIG. 5, this kind of oscillation occurs because of the groove 1 in which the tension band of the block 101 is fitted.
01c, and with the point a fixed on the pulley groove surfaces 102a and 102b, the center line of the block 101 is aligned with the speed change pulley 10.
Comparing the case where the tension band is aligned with the radial direction R of No. 2 (see the chain line in Fig. 5) and the case where it is inclined at an angle θ with respect to the radial direction R (see the solid line in Fig. 5), the block 101 to which the tension band is fitted is compared. When the block 101 is inclined at an angle θ with respect to the pulley radial direction R, the groove 101c is located further away from the pulley rotation center O as a whole, so the tension band wrapped around the speed change pulley 102 Due to the pushing force F against the pulley rotation center O, the block 10
1 will be moved to a vertical position on the speed change pulley 102.

On the other hand, if the center of gravity of the block 101 is located above the center body of the tension band, the lower part of the block 101 will be inclined toward the pulley rotation direction T when it is running in a straight line before engaging the pulley. As shown in FIG. 6a, when the block 101 engages with the pulley groove surfaces 102a and 102b of the speed change pulley 102, the cross section along the center line of the block is as shown in FIG. 6b.
has a hyperbolic shape and has a small pulley angle with respect to the block angle. Therefore, as in the case described above, when the block 101 engages with the pulley groove surfaces 102a and 102b of the speed change pulley 102,
Only the upper end of the block 101 is the speed change pulley 102.
The block 101 comes into contact with the pulley groove surfaces 102a and 102b, and the block 101 swings using the contact portion _P2 as a fulcrum and the groove in which the tension band is fitted as a point of force.

As described above, if the block 101 is inclined with respect to the radial direction of the pulley when it engages with the speed change pulley 102 due to the position of the center of gravity of the block 101, the block 101 will swing as described above. Due to the rocking, friction occurs at the fitting portion between the block 101 and the tension band, which generates heat, resulting in a local temperature rise in both the block and the tension band. This causes thermal aging of the rubber constituting the tension band, causing cracks in the tension band, and the cracks reaching the core, causing premature breakage of the tension band.

Furthermore, when the block engages with the speed change pulley, if it is inclined with respect to the radial direction of the pulley, only the upper end of the block comes into contact with the pulley groove surface of the speed change pulley, as described above, but this causes the block to The side pressure that should be applied to the entire side surface is concentrated only on the upper end of the block, making the block more likely to chip and causing early breakage of the block.

Therefore, in order to prevent the block from swinging as described above, when the block engages with the speed change pulley, it is necessary to do so in a state that coincides with the radial direction of the pulley.

The present invention has been made in view of the above, and an object of the present invention is to provide a V-belt for high-load transmission, which prevents the blocks from swinging when the speed change pulley is engaged.

(Means for Solving the Problem) In order to achieve the above object, the present invention includes an endless tension band having a center body, and a plurality of grooves in which the tension band is removably fitted in the width direction. A concave portion is formed in the upper part of the tension band, and a convex portion that engages with the concave portion is formed on the upper surface of the groove of the block. In a V-belt that is locked in the longitudinal direction, the block is
The block is composed of an upper beam part, a lower beam part, and a center pillar part connecting the central parts thereof, and the groove is formed in a space surrounded by both beam parts and the center pillar part, and the center of gravity of the block is It is characterized by being disposed in the center pillar portion and near a position approximately corresponding to the center body of the tension band.

(Function) Since the center of gravity of the block is located near the center pillar of the block and at a position approximately corresponding to the center body of the tension band, in the straight running state before engaging and wrapping around the speed change pulley, The block is held substantially perpendicular to the tension band, and the block engages the speed change pulley in alignment with the radial direction of the pulley, so that no rocking of the block on the pulley occurs.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the V-belt 1 according to the present invention includes a pair of tension bands 2 and 3, and a plurality of blocks 4 that are fixed to the tension bands 2 and 3 in their longitudinal direction. It is composed of. Block 4
Grooves 5 and 6 are formed on the side surfaces of the side surfaces 4a and 4b, respectively, and into which the tension bands 2 and 3 are removably fitted in the belt width direction, and a convex portion ( A convex portion 7 for the groove 6 is shown), and the lower surface is a curved convex surface (only a convex curved surface 8 for the groove 6 is shown).

The tension bands 2 and 3 each have a core body 10 embedded in a rubber member 9. Note that canvas is provided on the upper and lower surfaces of the rubber member 9 as necessary. In addition, tension band 2,
The upper and lower surfaces of the tension band 3 are provided with recesses (only the recesses 11 and 12 of the tension band 3 are shown) that engage with the convex portions or curved convex surfaces of the grooves 5 and 6 of the block 4. The convex portion 7 and the curved convex surface 8 are adapted to mesh with the concave portions 11 and 12. As a result, the tension bands 2, 3 and the block 4 are fixed in an uneven engagement relationship in the longitudinal direction of the belt.

The center of gravity of the block 4 is located above the center body 10 of a reinforcing member made of a material other than metal that has a higher specific gravity than the resin material constituting the main part of the block or a metal reinforcing member buried inside the block, for example. By making adjustments such as reducing the proportion of parts,
In the state of engagement with the tension bands 2, 3, the tension bands 2,
The block 4 is located near a position approximately corresponding to the center body 10 of the tension band 3 (center body 10) in the straight running state.
(centerline of) is held vertically and is configured to engage the pulley in that state. Note that the center of gravity of the block 4 is located in the vicinity of a position that substantially corresponds to the center body 10 of the tension bands 2 and 3, which means that the center pillar portion that connects the upper beam portion 4c and the lower beam 4d of the block 4 at their central portions. 4e, i.e. the line A-A and line B-B in FIG.
This means that the center of gravity of block 4 is located in the area between. From the standpoint of stability, the center of gravity of the block 4 is located at the center pillar portion 4e, and assuming the block height is 1, the center of gravity is at a position of -0.1 to +0.1 in the vertical direction from the position of the center body 10. It is desirable that the

With the above configuration, since the center of gravity of the block 4 is located at a position approximately corresponding to the center body 10 of the tension bands 2 and 3, which is the neutral line, the Even when subjected to air resistance during straight running, the block 4 has good stability and maintains a state substantially perpendicular to the tension band 3.

Therefore, while the block 4 remains substantially perpendicular to the tension band 3, the block 4 of the V-belt 1
Since the block 4 engages with the speed change pulley, the block 4 engages with the speed change pulley with its center line aligned with the radial direction of the pulley, and the block 4 does not swing on the speed change pulley.

Therefore, no heat is generated due to friction at the engagement portion between the block 4 and the tension bands 2, 3, and the tension bands 2, 3 do not generate heat due to friction.
Heat deterioration of the rubber member 9 of No. 3 is prevented, uneven contact of the block 4 with the speed change pulley is prevented, and side pressure on the block 4 is dispersed, so that the belt life is extended.

Further, as a means for adjusting the position of the center of gravity of the block, as shown in FIG.
a, center pillar part 14b and lower beam part 14c
The upper beam portion 14a of the block 14 may be provided with a recess 14d, and the volume of the recess 14d may be changed.

(Effects of the invention) As described above, in the present invention, the center of gravity of the block is located near the center pillar of the block and at a position approximately corresponding to the center body of the tension band.
Swinging of the block when engaged with the speed change pulley is prevented, thereby avoiding heat generation and concentration of side pressure at the engagement portion between the block and the tension band, resulting in an extended belt life.

[Brief explanation of the drawing]

Figures 1 and 2 illustrate an embodiment of the present invention. Figure 1 is a side view of the V-belt for high-load transmission of the present invention, and Figure 2 is a sectional view taken along the - line in Figure 1. be. Figures 3a and b are diagrams showing the relationship between the block and the speed change pulley when the block is not inclined with respect to the tension band, and Figures 4a and b are diagrams in which the upper part of the block is in the pulley rotation direction with respect to the tension band. Figures 3a and b are similar to when the block is tilted to the side, Figure 5 is an explanatory diagram of the rocking of the block, and Figures 6a and b are where the lower part of the block is in the pulley rotation direction with respect to the tension band. A similar view to Figures 3a and b in the case of tilting to the side, Figure 7
The figure is a perspective view of a modified block. 1... V belt, 2, 3... Tension band, 4, 14
...Block, 5, 6...Groove, 7...Protrusion, 10
...mind-body, 11...concavity.

Claims (1)

[Claims for Utility Model Registration] An endless tension band having a center body, and a plurality of blocks having grooves in which the tension band is removably fitted in the width direction, and a recess in the upper part of the tension band. In the V-belt, a convex portion that engages with the concave portion is formed on the upper surface of the groove of the block, and the block is engaged with the concavo-convex portion and the block is locked with respect to the tension band in the longitudinal direction of the belt. The block is composed of an upper beam part, a lower beam part, and a center pillar part connecting the central parts thereof, and the groove is formed in a space surrounded by both beam parts and the center pillar part, and the center of gravity of the block is A V-belt for high-load transmission, characterized in that the V-belt is disposed in the center pillar portion and near a position substantially corresponding to the core of the tension band.