JP2516855B2 - Toothed belt and transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt and a transmission device provided in a drive mechanism of an internal combustion engine, for example.

[0002]

2. Description of the Related Art In a toothed belt, in order to improve durability such as chipping resistance and abrasion resistance, it is sufficient to increase the rigidity of the tooth surface. Therefore, conventionally, it has been covered with a vulcanized rubber film. A structure in which the entire tooth surface is covered with a hard canvas is known. In addition, conventionally, the cushioning effect generated by abutting the tooth groove whose tooth height is greater than the pulley groove depth and the pulley groove portion was used to suppress the generation of meshing noise between the toothed belt and the toothed pulley. The composition is known.

[0003]

Recently, there has been a strong demand for the development of a toothed belt having both durability and quietness. However, if the belt teeth of the toothed belt are covered with a hard canvas in order to cope with the durability, the belt teeth will have rigidity because the tooth rubber part and the canvas are integrated, and the tooth part will become the pulley groove part. If it is configured to abut, a collision noise is generated by the belt tooth portion and the pulley groove portion, and quietness cannot be obtained. An object of the present invention is to obtain a toothed belt satisfying both durability and quietness at the same time, and a transmission including a combination of a toothed pulley with which the performance of the toothed belt is sufficiently exhibited. It is a thing.

[0004]

The toothed belt according to the present invention is such that the vulcanized rubber at least on the tooth top of the canvas is substantially removed.
It is characterized by standing up . Further, in the transmission device according to the present invention, if the vulcanized rubber portion of at least the tooth top of the canvas impregnated with the vulcanized rubber is substantially removed.
It is characterized in that it is provided with a toothed belt having elasticity due to fluffing of the canvas at the top of the tooth and a toothed pulley having a groove with which the tooth top of the toothed belt abuts.

[0005]

The present invention will be described below with reference to the illustrated embodiments.
FIG. 1 shows a transmission device including a toothed belt 10 and a toothed pulley 20 according to an embodiment of the present invention. Endless belt 1
0 has a belt tooth 11 and a tooth bottom 12 on the inner surface side.
The pulley 20 has tooth portions 21 and groove portions 22 formed at equal intervals on the outer peripheral surface thereof, and these tooth portions 21 and groove portions 22 are formed.
Have substantially the same cross-sectional shape as the tooth bottom portion 12 and the belt tooth 11 of the belt 10. Although the pulley 20 is made of metal, the belt 10 is basically made of synthetic rubber, and the entire tooth surface thereof is covered with canvas as described later.

FIG. 2 shows a cross section of the toothed belt 10. In the belt tooth 11, the outer shapes of the side surface 13 and the surface of the tooth top portion 14 are arcuate, and the outer shape of the surface of the tooth bottom portion 12 is substantially linear. A core wire 16 is provided inside the belt main body 15 extending in the longitudinal direction of the belt 10. The entire tooth surface is covered with the canvas 30. The canvas 30 is the belt 10
A bulky processed thread portion 31 (stretchable thread) extending in the longitudinal direction of
The non-stretchable thread portion 32 extends in the width direction of the belt 10.

The surface of the canvas 30 is covered with a vulcanized rubber film (not shown in the drawing), and the belt teeth 11 and the tooth bottom portion 1 are covered.
A composite part of the canvas 30 and the rubber is formed on 2. That is, a part of the rubber forming the belt teeth 11 and the tooth bottom 12 enters into the uneven portion of the surface of the weave structure of the canvas 30 on the rubber tooth side during the pressure vulcanization and is firmly bonded to the canvas.

FIG. 3 is an enlarged view of the canvas 30 at the top 14 of the tooth, and FIG. 4 is an enlarged view of the canvas 30 at the bottom 12 of the tooth. As shown in FIG. 3, at the tooth top 14,
The thickness of the bulky processed thread portion 31 and the non-stretchable thread portion 32 in the direction perpendicular to the back surface of the belt is smaller than that of the tooth bottom portion 12 shown in FIG. On the other hand, as shown in FIG. 4, in the tooth bottom portion 12, the thickness of the bulky processed thread portion 31 and the non-stretchable thread portion 32 in the direction perpendicular to the belt back surface is smaller than that of the tooth top portion 14.

The reason for this difference in thickness will be described. In the manufacturing process of the toothed belt, a rubber sheet is wound around the canvas, and the core wire 16 is further wound on the rubber sheet. At this time, the canvas portion of the tooth top portion 14 in FIG. 3 is located on the mold groove, and the canvas can be freely deformed in the groove direction of the mold. Therefore, the pressure that the canvas receives during pressure vulcanization is only that it is pressed by the vulcanization pressure from the rubber side, which has fluidity due to heat, to the tooth profile of the mold groove, and the processed yarn that is covered with the rubber film Fully retains its bulkiness. On the other hand, in the tooth bottom portion 12 of FIG. 4, since the canvas on the convex portion of the mold is clamped as much as possible by the core wire 16, the non-stretchable thread portion is deformed into a flat elliptical shape in the tightening direction, and is bulky. In the yarn portion, the bulkiness is the minimum.

As described above, the canvas 30 is compressed by the core wire 16 at the tooth bottom portion 12, but has almost the same thickness at the tooth top portion 14 as that before being processed. Therefore, the elasticity of the canvas 30 can be restored by removing the rubber film from the canvas 30 at the tooth top 14.
The thickness of this elastic layer is the difference (AB) between the thickness A of the bulky processed thread portion 31 at the tooth top 14 and the thickness B of the bulky processed thread portion 31 at the tooth bottom 12. In this example, the rubber film of this layer is removed by polishing with, for example, a polishing machine or a paper file as described later,
Regains elasticity. Hereinafter, this difference (AB) is referred to as a canvas elastic layer, and this canvas elastic layer has a fluff of 3
3 is also included.

That is, in the tooth top 14, the rubber film of the canvas 30 is substantially removed, and the canvas 30 of the tooth top 14 is provided with a fluff 33 as shown in FIG. In this way, since the fabric is fluffy, the canvas 30 (fluff 33) of the tooth top 14 has a predetermined elasticity. On the other hand, the canvas 30 is not ground in the portion other than the tooth top portion 14, and therefore, the rigidity sufficient to maintain the durability of the belt 10 is secured.

In the present embodiment, the pitch of the belt teeth 11 of the belt 10 is 8 mm. The width of the fluff 33 (the dimension in the left-right direction in FIG. 2) is 2 mm in the front and back with respect to the center line of the belt tooth 11, and the height of the fluff 33 is 0.1 to 0.5.
mm. Needless to say, these numerical values are merely examples, and predetermined numerical values can be set according to the purpose.

FIG. 5 shows an example in which the width of the fluff 33 of the tooth top 14 is relatively small, and this width is, for example, about 1 mm. FIG. 6 shows an example in which the width of the fluff 33 is relatively large.
Has reached side 13. As another example, if attention is paid only to the purpose of preventing a collision sound with the pulley groove portion, the entire tooth surface may be raised.

FIG. 7 shows a toothed belt 10 and a toothed pulley 20.
It shows a meshed state with. The groove 22 of the pulley 20 has a cross-sectional shape that matches the cross-sectional shape of the belt teeth 11 of the belt 10. The depth of the groove portion 22 of the pulley 20 is smaller than the height of the belt teeth 11 of the belt 10 by the amount of compression of the elastic elastic layer portion of the canvas 30 at the tooth top portion 14 during meshing. That is, when the belt teeth 11 of the belt 10 are completely meshed with the groove 22 of the pulley 20, the fluff 33 of the belt 10 abuts the groove 22 so that the canvas 30 is sufficiently compressed. ing.

As described above, the transmission device including the belt 10 and the pulley 20 according to the present embodiment removes the rubber film by polishing the tooth top portion 14 of the canvas 30 that covers the entire tooth surface of the belt 10. Because of the elasticity, no collision noise is generated between the tooth crest 14 of the belt 10 and the pulley groove 22 when the belt 10 and the pulley 20 are meshed with each other. Further, since the belt 10 is covered with the vulcanized rubber film other than the tooth top portion 14, the belt 10 has sufficient rigidity, and therefore the durability of the belt 10 is secured. The portion of the belt tooth 11 that affects the durability is the side surface 13, and no large stress is generated in the belt tooth top portion 14 when the belt 10 and the pulley 20 mesh with each other. That is, the extent to which the canvas 30 functions as a strength member at the tooth crest 14 is small, and removing the rubber film from the canvas 30 at the tooth crest 14 does not impair the durability of the belt.

Next, the effect of preventing the collision noise between the belt teeth 11 and the pulley groove portion 22 according to this embodiment will be described with reference to FIG. 8A shows an example in which the entire tooth surface of the belt 10 is erected, FIG. 8B shows an example in which only the tooth bottom 12 is erected, and FIG. 8C shows only the tooth top 14 is erected. FIG. 8 (d) shows an example in which the parts other than the tooth crest 14 are erected.
Shown respectively. That is, FIG. 8C shows the effect of this embodiment, and the others show the effect of the comparative example.

As can be seen from these figures, when the entire tooth surface (a) or only the tooth crest 14 (c) is raised, the sound pressure level in the frequency range of 5 to 9 kHz is lowered. If only the bottom of the tooth (b) or the portion other than the top of the tooth (d) is raised, the sound pressure level in the frequency range of 5 to 9 kHz cannot be lowered. In FIGS. 8 (b) and 8 (d), the collision sound is generated by the tooth top and the pulley groove because the tooth top is hard, whereas in FIGS. 8 (a) and 8 (c), This is because the top portion has a cushioning property, so that the generation of a collision noise due to the tooth top portion and the pulley groove portion is prevented.

As shown in these figures, 1 to
The sound in the frequency range of 4 kHz occurs regardless of the position of the fluff 33 on the tooth portion of the belt. This sound is belt 10 and pulley 2
It is generated by the meshing of 0, is not generated by the collision between the top 14 of the belt 10 and the pulley groove 22, and cannot be prevented by the fluff 33.

Next, referring to FIG. 9, the belt 1 of the present embodiment.
The removal of the rubber film covering the canvas 30 of No. 0 will be described. In the manufacturing process of the belt 10, the canvas 30 having an unvulcanized rubber layer, the rubber sheet, and the core wire 16 are wound and placed in a vulcanizing can, and vulcanized under pressure to form a tooth profile, as shown in FIG. Then, the molded product is inverted and the belt teeth are directed outward, and the molded product is wound around a drum (not shown). Then, the outer periphery of this belt is polished by a polishing machine provided with industrial diamond, and the canvas of the tooth top 14 is fluffed. Instead of this polishing machine, the canvas of the tooth top portion 14 may be made to stand up manually by using a paper file or the like.

FIG. 10 shows a toothed belt 10 according to another embodiment of the present invention. In this toothed belt 10, the tooth top 14
The canvas 30 is not fluffy, and the rubber film is removed by utilizing a solvent, for example. Therefore, similarly to the toothed belt shown in FIG. 2, the tooth crest portion 14 has elasticity, and similarly to the effect described above, the generation of the collision noise with the pulley is prevented.

In the above embodiment, the surface of the canvas 30 is described as being covered with the vulcanized rubber film. However, instead of coating the canvas 30 with the rubber film obtained by the solvent-based treatment, a film by a water-based treatment represented by RFL or the like may be applied, or the former treatment may be overlaid on the latter. It is also possible to do so. Also in this case, the elasticity of the canvas of the tooth top 14 can be obtained by polishing with a polishing machine or the like.

Further, the present invention does not limit the shape of the belt tooth 11, and it is preferable that the tooth top 14 has a curved surface, but the side surface 13 may have any shape. The tooth top 14 does not have to have a single arc-shaped curved surface as in the illustrated embodiment, but may have a plurality of arc-shaped curved surfaces.

Further, the present invention can of course be applied to a double-toothed belt having belt teeth on both sides.

In the above embodiment, the canvas was twill weave, but the present invention is not limited to this. For example, plain weave,
A satin weave or other modified weaves may be used.
Nylon yarn may be used for the bulky textured yarn and non-stretchable yarn constituting the canvas, or other synthetic fibers may be adopted. Further, the material of the rubber film can be appropriately selected according to the purpose, such as chloroprene rubber if the weather resistance is important and hydrogenated nitrile rubber if the heat resistance is important.

[0025]

As described above, according to the present invention, both durability and quietness of the toothed belt can be satisfied at the same time, and further, the performance of the toothed belt can be sufficiently exhibited. A transmission is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a transmission device including a toothed belt and a toothed pulley according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a toothed belt according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an enlarged canvas at the tooth top.

FIG. 4 is a cross-sectional view showing an enlarged canvas at the tooth bottom.

FIG. 5 is a perspective view showing an example in which the width of the tooth top fluff is relatively small.

FIG. 6 is a perspective view showing an example in which the width of the tooth top fluff is relatively large.

FIG. 7 is a cross-sectional view showing a meshed state of a toothed belt and a toothed pulley.

FIG. 8 is a diagram showing an effect of preventing collision noise between a belt tooth and a pulley groove portion.

FIG. 9 is a perspective view showing a step of removing a rubber film of a canvas.

FIG. 10 is a sectional view showing a toothed belt according to another embodiment of the present invention.

[Explanation of symbols]

 10 Toothed belt 11 Belt teeth 14 Tooth top 20 Pulley 30 Canvas 33 Fuzz

Claims (3)

(57) [Claims] 1. A toothed belt in which the entire tooth surface is covered with a canvas impregnated with vulcanized rubber, in which at least the vulcanized rubber at the top of the tooth of the canvas is substantially removed so that it stands up.
A toothed belt, wherein the canvas on the tooth top has elasticity due to fluff . 2. By polishing the tooth top of the canvas,
The toothed belt according to claim 1, wherein the vulcanized rubber on the tooth top is removed to make it stand up . 3. The vulcanized rubber-impregnated canvas is substantially fluffed by removing the vulcanized rubber at least at the top of the tooth, and the tooth is raised.
A transmission device comprising: a toothed belt having elasticity due to fluffing of the top canvas, and a toothed pulley having a groove portion that meshes with the toothed belt and is in contact with the tooth top.