JPH0642592A - V-ribbed belt and transmission - Google Patents

Abstract

PURPOSE:To prevent reduction of the belt tension to be generated simultaneously with the belt slip and noises and to maintain and improve the transmission capacity of the belt by securing the overall contact of a V-shaped rib with a pulley. CONSTITUTION:In a belt where a group of V-shaped ribs are integratedly formed to the underside of a flat belt body, one end of the side part 8 of the respective ribs in contact with the pulley are surcumscribed with the arc forming a R- shaped rib bottom 10 having a center point 9 outside the section of the V-shaped rib, and at the same time, the other end is formed by a large arc which is inscribed with the arc forming the tip 12 of the R-shaped rib having a center point 11 inside the section of the V-shaped rib. The center point of this large arc is located outside the section of the V-shaped rib and the rib side 8 is constituted by the curved surface which is gradually swollen outward as a whole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-ribbed belt in which a plurality of V-shaped ribs extending in the longitudinal direction of the belt are integrally formed on the lower surface of a flat belt body which is one of power transmission belts, and this belt. The present invention relates to a power transmission device.

[0002]

2. Description of the Related Art A V-ribbed belt has a larger power transmission force than a flat belt for power transmission due to the expansion of the contact surface with the pulley due to the presence of the V-shaped rib. However, the presence of the V-shaped rib group means that when the belt is wound around a pulley to run, especially when this belt is wound around a small-diameter pulley, the tip of the V-shaped rib of the belt spreads in the width direction and the rib angle is small. Also, the smaller the pulley diameter, the greater the decrease in rib angle. Along with this, the belt rib portion itself becomes slender, and due to this, the belt rib portion makes partial contact due to the relationship with the pulley, the load of the driven pulley increases, and the contact angle decreases, so that sounding due to slip easily occurs. In addition, the V-ribbed belt has a problem to be solved, such as a decrease in belt tension and a decrease in power transmission capability.

In order to solve the problems derived from these V-ribbed belts, (1) when the belt is bent with a small radius of curvature,
A V-ribbed belt in which the rib angle of the belt is set larger than the V-groove angle of the pulley in consideration of the reduction of the rib angle. (2) A radius is provided on each rib bottom portion and each rib tip portion of the belt, and the radius portions on these both portions are
A V-ribbed belt in which the side surface portion of the belt rib portion is formed by a straight line in contact with this. (3) A V-ribbed belt in which the rib tip portion and the rib side surface portion of the belt are formed by a single common arc surface having a center point inside the V-shaped rib cross section. Have been proposed.

[0004]

Even in the above-mentioned variously considered V-ribbed belts, individual problems still remain in each belt. Specifically, in the belt having the above-mentioned configuration (1), the change in the belt rib angle due to the bending diameter of the belt is still large, and when the belt is wound around various pulleys whose diameters are greatly different, The belt and the pulley cannot be fitted smoothly unless the V groove angle is changed according to the pulley diameter.

Further, in the belt having the above-mentioned constitution (2), the deformation of the rib tip portion of the belt is largely alleviated, but the deformation of the straight portion of the rib side surface portion is still large, similar to the above-mentioned (1). , The belt and pulley do not fit smoothly.

Further, in the belt having the above-mentioned structure (3), the amount of change in the V-shaped rib angle of the belt due to the bending diameter of the belt is certainly small, but the side surface of the rib portion has a radius of curvature. It is formed on a convex convex surface with a large number, and the shape is too different from the V groove side surface of the pulley.
Proper surface contact cannot be expected, which is not practical in terms of power transmission efficiency.

Further, in the invention concerning the relationship between the V-ribbed belt and the power transmission mechanism, if the rib angle of the belt is set large so as to match the pulley of small diameter, the rib angle of the belt becomes large for the pulley of large diameter. Since the belt is too large, it is difficult to accurately match the belt and the pulley. When an inertial load due to the clutch mechanism acts on such a pulley portion, a further slip noise of the belt increases. If the tension of the belt is increased in order to suppress the generation of this slip noise, the load on the pulley shaft will increase due to the increased tension, resulting in damage to the bearing and shortening the life of the belt itself. . Conversely, if the rib angle of the belt is set to be small so that it matches a pulley with a large diameter, the rib angle of the belt will be too small for a pulley with a small diameter, and only the tip of the rib of the belt will be strong on the pulley. As a result, the rib tip wears early and the belt tension decreases accordingly.

Further, if the winding angle of the belt with respect to the pulley is increased, slipping and sound generation can be prevented in the pulley portion, but since the sum of the belt winding angles of all the constituent pulleys is limited to 360 °, the other pulley portions As a result, the wrapping angle of the pulley is reduced, slip and sound are generated in the pulley portion, and the power transmission capability is locally reduced. Furthermore, in order to increase the total winding angle, if a rear pulley that bends the belt in reverse is inserted, it is necessary to add one pulley, which increases the cost, and as a result, greatly shortens the life of the belt. Will result.

The present invention is intended to improve the problems inherent in the various V-ribbed belts and the problems occurring in all power transmission devices using the V-ribbed belts.
By forming both sides of the rib portion of the belt with curved surfaces that swell gently with a particularly large radius, the rib angle of the V-shaped rib of the belt changes even when folded around pulleys of different diameters. Less depending on the groove angle of the V groove of the pulley (JASO, S
The tolerance angle of the V groove of a V-shaped pulley defined by international standards such as AE and RMA is approximately 40 ± 1 °), or a single V groove with a large difference in pulley diameter. Maintains proper surface contact over a wide range even with various angled pulleys, thereby suppressing belt squeal (slip noise) generated when driving the belt, maintaining belt tension, and efficient power transmission An object of the present invention is to provide a V-ribbed belt that can maintain performance and a power transmission device using the belt.

[0010]

In order to achieve the above object, a V-ribbed belt according to the present invention and a power transmission device using this belt have the following configurations. On the lower surface of the flat belt body, a plurality of V-shaped ribs extending in the belt longitudinal direction are integrally formed with the belt body,
In this V-shaped rib, both side surfaces of each rib in contact with the pulley have curved surfaces that bulge gently with a large radius. That is, one side surface portion of each rib contacting the pulley circumscribes an arc forming a rounded rib bottom having a center point outside the V-shaped rib section, and the other side surface portion inside the V-shaped rib section. It is characterized in that it is formed by a large arc inscribed in the arc forming the tip of the rounded rib, and the center point of this large arc is located outside the side surface of the V-shaped rib.

Further, the power transmission device using the V-ribbed belt is composed of a driving pulley having a large diameter difference of 40 mm to 180 mm and a plurality of driven pulleys respectively attached to auxiliary machines, of which A clutch mechanism is interposed between at least one auxiliary machine and a driven pulley, and the V-ribbed belt is hooked between the pulleys in a drive mechanism capable of increasing / decreasing the load during rotation of the pulleys.

[0012]

When the V-ribbed belt according to the present invention is wound around the V-groove pulley and is run, when the V-shaped rib portion of the belt is wound around the pulley, the rib angle at the tip of the rib portion is deformed to a small extent. Accordingly, the side surface of the V-shaped rib becomes thin. According to the present invention, when the side surface portion of the V-shaped rib portion of the belt, which has a gently bulging curved surface, is fitted and contacted with the V groove of the pulley,
The gently bulging curved surface of the side surface absorbs the thinning of the V-rib portion that is generated as the rib angle at the tip of the V-shaped rib is reduced, and planarizes the V-shaped rib portion of the belt. Of the belt, the local concentration of stress in the V-shaped rib portion of the belt, which is caused by the partial contact of the V-shaped rib portion, is eliminated, slipping of the belt on the pulley, and subsequent belt Surely prevent the decrease in tension.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a specific embodiment of the V-ribbed belt according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a part of a V-ribbed belt embodying the present invention, and FIG. 2 is an enlarged end view of a V-shaped rib constituting the belt. The V-ribbed belt (1) is integrally formed with the flat belt main body (2) and the lower surface thereof, and is composed of a plurality of, for example, four V-shaped ribs (3) extending in the longitudinal direction. The flat belt main body (2) has a rope-like tensile body (5) of low elongation and high strength embedded in parallel in the rubber layer (4), and at least one sheet is provided on the upper surface of the rubber layer (4). The rubber canvas (6) is laminated and attached.

A V-shaped rib (3) on the lower surface of the flat belt main body (2), which is made of the same material as the rubber layer (4) forming the belt main body (2) and in which the essential part of the present invention exists.
Is characterized in that it is formed with a large curved surface that gently bulges with a large radius on both side surfaces that contact the V groove of the pulley.

One end of each of the upper and lower sides of the side surface portion (8) of each V-shaped rib (3) has a center point (9) outside the V-shaped rib cross section, and is a rounded rib bottom located on both sides of the upper portion of the rib. (1
0) circumscribes the arc of which the other end has a center point (11) (11) inside the V-shaped rib cross section and is located at the tip of the rib.
It is formed by a large circular arc surface which is inscribed in the circular arc forming 2) and has a center point (7) on the outside of the V-shaped rib cross section and which is a gently bulging curved surface.

Disclosed here is an embodiment of the V-ribbed belt (1) embodying the present invention having four ribs in more detailed concrete numerical values. The V-ribbed belt (1) has a central point (9) forming a rib bottom (10). The earl is 0.15m
m, the radius having the center point (11) forming the rib tip (12) is 0.5 to 1.0 mm, and the center point (7) forming the side surface (8) of the rib composed of a large arc surface. The radius is 4.0 to 6.0 mm. Further, a crossing angle θ of a straight line (tangent line) on the side surface of the rib connecting the inner contact point with the circular arc as the center point (11) and the outer contact point with the circular arc as the center point (9) is 40 ± 3 °.

In the V-shaped rib (3), nylon, vinylon, polyester, aromatic polyamide, cotton,
Short fibers (13) consisting of short fiber yarns such as pulp alone or mixed yarns thereof are embedded with orientation in the belt width direction.

In the above description, the rounded rib tip is formed of a pair of left and right circular arcs, but it is also possible to form the rib tip by one large circular arc. . However, the rounded rib tips constituted by the pair of left and right arcs are more likely to be connected to the flattening of the belt both side surface portions (8), and can have a clearly superior effect in achieving the present invention.

Next, the V-ribbed belt (4
PK870) (hereinafter referred to as “Example”) and a conventional V-ribbed belt (hereinafter referred to as “Comparative Example”) having a linear shape on the (2) th side surface in the section of the above-mentioned conventional technology, Specific measurement results were obtained.

[Table 1]

The results of the measurement of the folding, in which the changes in the angle of the belt rib portion due to the static belt bending were obtained using pulleys with various diameters, are shown in the graph of FIG. According to the graph, in the belt of the example, the change of the rib angle of the V-shaped rib with respect to the increase of the bending diameter of the belt is very small, but in the belt of the comparative example, the V-shaped rib It has been demonstrated that the change in rib angle is large.

Next, a power transmission device using the V-ribbed belt (1) described in detail above will be described. This power transmission device (15) is one in which a single V-ribbed belt is mounted on a drive mechanism composed of a drive pulley and a plurality of driven pulleys whose diameters are greatly different from each other. As shown in FIG. 16) has a drive pulley (Dr) with a diameter of 120 to 160 mm, a generator (17) as an auxiliary machine has a driven pulley (Dn) with a diameter of 40 to 70 mm, and an air compressor (18) also as an auxiliary machine. Has a diameter of 9
Each driven pulley (Df) of 0 to 180 mm is laid out in a predetermined form, a clutch mechanism (19) is interposed between the air compressor (18) and the driven pulley (Df), and the load of the air compressor is the pulley. It is configured such that it can be increased or decreased during rotation of (Df).

The pulley groove angle of each of these pulleys is SA
40 ± 1 according to international standards such as E, RMA, JASO
It is set to °. The V-ribbed belt (1) is hung between the pulley groups having the above-described configuration.

In the power transmission mechanism having the structure shown in FIG. 4, the power transmission device disclosed with more specific numerical values, that is, the drive pulley (Dr) having a diameter of 120 mm and the diameter of 60 m is used.
m driven auxiliary pulley (Dn) and clutch mechanism (1
9) is attached to the auxiliary machine drive device having the same auxiliary machine pulley (Df) with a diameter of 95 mm.
And the two belts (4PK87
Drive pulley (Dr) in the state where the 0-type belt) is sequentially mounted and the clutch mechanism is operated to apply an inertial load.
The measurement result of the squeal (slip noise) test of each belt due to the change in the rotation speed of the above was obtained as a graph shown in FIG. Note that the tension at which the sound starts to be generated in relation to this graph is called the squealing limit tension.

From the graph, when the belt tension is high,
There is no sound, but sound is generated when the tension of the belt becomes low. Since the belt of the example has a small resistance at the tip of the V-shaped rib at the time of belt slip, it is proved that the belt tension at the time of sounding the belt is much smaller than that of the belt of the comparative example. , Drive pulley (D
It was confirmed that there was a difference of 7.8 kgf in the tension between both belts at the time of 5000 rpm rotation of r).

[0025]

The V-ribbed belt according to the present invention is folded around a V-groove having a small diameter, reduces the rib angle generated on the V-shaped rib of the belt, and the resulting tendency of thin rib deformation of the entire rib. In addition, the gently bulging V-shaped rib side surface absorbs and alleviates the extremely thin deformation of the rib portion, and the flattened side surface portion of the belt rib portion has a wide area over the V groove of the pulley. By maintaining proper contact and eliminating partial stress concentration on the side surface of the belt rib part, it is possible to prevent a decrease in belt tension that occurs in response to the occurrence of a belt slip noise, thereby maintaining the power transmission performance of the belt,
And this can be improved.

Further, the presence of the rounded rib tips of the belt has the effect of extending the life of the belt, and the gentle bulging curved surface of the belt rib side surface is inscribed with the arcuate surface of the rounded rib of the rib tip, thereby It greatly contributes to improving the wide area surface contact with the V groove of the pulley, and further contributes to the improvement of the efficient power transmission capability of the belt.

Further, in the power transmission device according to the present invention, one V-ribbed belt is hung on a plurality of pulleys having greatly different diameters, and the pulleys and belts are folded when the device is driven. There is little large slip phenomenon in the meantime, and there is little abnormal sound, and the various auxiliary machines that make up the apparatus can each exhibit their full performance.

[Brief description of drawings]

FIG. 1 is a perspective view of a part of a V-ribbed belt embodying the present invention.

FIG. 2 is an enlarged end view of one V-shaped rib forming the belt.

FIG. 3 is a graph showing changes in belt rib angle due to static belt bending.

FIG. 4 is a schematic diagram of a power transmission device embodying the present invention.

5 is a graph showing a situation where a belt squeal (belt slip noise) of a V-ribbed belt is generated according to a change in rotation speed of a drive pulley using the apparatus shown in FIG.

[Explanation of symbols]

 1 V-ribbed belt 2 Flat belt main body 3 V-shaped rib 7 Center point for determining side surface of rib 8 Side portion of rib 9 Center point for determining rib bottom 10 Rib bottom 11 Center point for determining rib tip 12 Rib Tip 15 Power transmission device 16 Motor 17 Generator (auxiliary machine) 18 Air compressor (auxiliary machine) 19 Clutch mechanism Dr Drive pulley Dn Driven pulley Df Driven pulley

Claims (7)

[Claims] 1. A belt in which a plurality of V-shaped ribs extending in the belt longitudinal direction are integrally formed on the lower surface of a flat belt main body, and one end of each side surface of each rib contacting the pulley is a rounded rib. It is characterized in that it is inscribed in an arc forming the tip, and the other end is inscribed in an arc forming the bottom of the rounded rib, and is constituted by a large curved surface which swells gently with a large radius. Ribbed belt. 2. A belt in which a plurality of V-shaped ribs extending in the longitudinal direction of the belt are integrally formed on the lower surface of a flat belt main body, and one end of the side surface of each rib contacting the pulley is V-shaped.
Large circular arc circumscribing an arc forming a R-shaped rib bottom having a center point on the outside of the V-shaped rib cross section and inscribed at the other end in an arc forming a R-shaped rib tip having a central point inside the V-shaped rib cross section The center point of this large arc is V
A V-ribbed belt characterized in that it is located outside of the rib section. 3. A crossing angle θ of straight lines (tangents) on both side surfaces of the rib connecting an inner contact with an arc forming the tip of the rounded rib and an outer contact with an arc forming the bottom of the rounded rib is 40 ± 3.
The V-ribbed belt according to claim 1 or 2, which is set at °. 4. A drive pulley having a diameter of 40 to 180 mm and a plurality of driven pulleys having a large difference in diameter between them, and a plurality of driven pulleys attached to each auxiliary machine, and a clutch mechanism interposed between at least one auxiliary machine and the driven pulley. 2. A power transmission device comprising a V-ribbed belt according to claim 1 mounted between pulleys in a drive mechanism capable of increasing and decreasing the load while rotating the pulleys. 5. A drive pulley having a diameter of 40 to 180 mm and a plurality of driven pulleys each having a large difference in diameter therebetween, and a plurality of driven pulleys attached to each auxiliary machine, and a clutch mechanism interposed between at least one auxiliary machine and the driven pulley. The power transmission device according to claim 2, wherein the V-ribbed belt according to claim 2 is mounted between the pulleys in a drive mechanism capable of increasing and decreasing the load while the pulleys are rotating. 6. The V-rib of the V-ribbed belt has a crossing angle θ of straight lines on both sides of the rib connecting an inner contact with an arc forming the tip of the R-shaped rib and an outer contact with an arc forming the bottom of the R-shaped rib. 6. The power transmission device according to claim 4, wherein the rib groove angle of the V groove of the pulley is set in the range of 3 ° and the rib groove angle of the V groove of the pulley is set in the range of 40 ± 1 °. 7. The power transmission device according to claim 4, wherein one of the auxiliary devices constituting the power transmission device is a generator, and the auxiliary device provided with a clutch mechanism is an air compressor.