JPH0582500B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention has an upper surface that is wider than the belt height,
This invention relates to a low edge type variable speed V-belt with high lateral pressure resistance and bending resistance. (Prior art) Conventionally, V-belts transmit power through the wedge effect that occurs when driving by wrapping around V-pulleys, so they have high lateral pressure resistance, and are especially suitable for variable-speed V belts with a wide upper surface.
A high degree of lateral pressure resistance is required for belts. Therefore, as a measure to increase such lateral pressure resistance, a stay flex layer in which short fibers are oriented in the width direction of the belt is used in the compression part, but when this belt is used in a variable speed pulley, Deformation of the belt occurs, and the more frequently the upper width of the pulley is opened and closed, the greater this deformation becomes, and eventually the belt reaches the end of its life due to peeling of the tensile rope and cracking of the tension layer. Furthermore, when the pulley is opened and closed, the belt repeatedly moves in the radial direction of the pulley under a large force, which causes problems such as side wear and changes in the gear ratio. In order to deal with this problem, the present applicant has previously installed one or more layers of suda record 7 in the belt cog part b provided on the lower surface of the belt, as described in Japanese Utility Model Application Publication No. 57-150645, and also in the longitudinal direction of the belt. We have proposed a variable speed V-belt B in which short fibers are embedded in a wave shape, and short fibers are embedded in the transverse direction not only between each sudare layer but also over the entire surface of the cog part (No. 5).
figure). (Problem to be solved by the invention) However, although the variable speed V-belt with cogs of this structure has good lateral pressure resistance compared to the conventional variable-speed V-belt, it is used in applications such as large combine harvesters, rice transplanters, etc. that require higher loads. When used under such conditions, the lateral pressure resistance and bending resistance are still insufficient, and there are problems such as belt deformation, side wear, and cog valley cracks. In order to solve this kind of problem, the present invention adjusts the placement position and thickness of the lateral sudare record layer in the compression section and improves the rubber between the sudare record layers, thereby improving lateral pressure resistance under high load conditions. The object of the present invention is to obtain a variable speed V-belt with cogs that has good bending resistance, is free from belt deformation, and is free from side wear and cog valley cracks. (Means for Solving the Problems) In order to achieve the above object, the present invention is characterized by a cogged variable speed V-belt having an extension section, a tensile section, and a compression section in order from the upper side, and the extension section is The compressed section is composed of a stretchable canvas and at least one layer of lateral strap records, and the compressed section has at least one layer of lateral strap records on the lower side of the tensile body part, and further includes a section between the lowermost surface of the cog valley part of the tensile rope layer. At least one layer of horizontal sagging records is provided at a position approximately bisected into two, and these lateral star records have a rubber layer containing HPH interposed between each lateral sagging layer and are embedded in a wave shape with the same period as the cog waveform, In addition, the variable speed V-belt has a sum of the thicknesses of the transverse strut record layers in the compression part in a range of 0.20 to 0.45 times the thickness between the tensile rope layer and the lowermost surface of the cog valley part. (Example) Hereinafter, a variable speed V-belt with cogs according to the present invention will be further described in detail with reference to the drawings. FIG. 1 is a partial perspective view of a variable speed V-belt with cogs according to the present invention, and FIG. 2 is a partial side view thereof. In the figure, A is the belt body, 2 is NR,
A cushion rubber layer made of a single material such as SBR, CR, NBR, or an appropriate blend of these materials.
In the cushion rubber layer 2, low elongation and high strength tensile ropes 1 such as polyester, aliphatic polyamide, aliphatic polyamide (trade name: Kevlar), or glass fiber are embedded in parallel along the longitudinal direction of the belt. and forms the tensile body part. An extension part and a compression part are formed on the upper and lower sides of the cushion rubber layer 2, and the extension part includes a suda record 31 made of polyester, aliphatic polyamide, aromatic polyamide, glass fiber, or carbon fiber. A bias canvas made of warp and warp yarns is buried in the horizontal direction, and on the upper side cross-striped record layer 3,
Alternatively, one to a plurality of layers, usually one to three layers, of stretchable canvas 5 made of wide-angle canvas or woolly-processed crimped nylon warp and normal nylon weft are laminated and adhered. In addition, one or more layers of Suda record 4 made of the same material are embedded in the horizontal direction in the extension part, and a compressed rubber layer 6 is further provided on the lower surface as usual. A cog part b with a constant pitch is formed, and along this cog part b, two layers of fiber cord 7 made of cotton, polyester, aliphatic polyamide, aromatic polyamide, glass fiber, etc. are formed in the transverse direction and in the belt longitudinal direction. On the other hand, it is buried in a wave shape with the same period as the cog waveform. Incidentally, the horizontal sagging 7 is not limited to the two layers mentioned above, but can be used in one to multiple layers, and usually has one to three layers.
It is preferable to embed the material in layers. The buried position of the two horizontal sag layers 7 is preferably at a position that approximately bisects the space between the tensile rope layer 1 and the lowermost surface 8 of the cog valley, or at a position slightly above that position. In addition, in order to improve the adhesion with each adjacent layer, the various sagging layers 3, 4, and 7 mentioned above contain at least 1 part by weight of resorcin resin (denoted as R) and silica (denoted as H) per 100 parts by weight of rubber. A rubber layer 9 containing 10 parts by weight or more of a chemical that generates methylene groups (denoted as H), such as 1 part by weight of hexamethylenetetramine, a so-called HRH compound, is embedded. Further, among the horizontal sag layers 3, 4, 7, 4, 7 of the lateral sagging layers buried in the lower part of the tensile rope 1
It is necessary for the total thickness to satisfy the following formula. That is, the distance between the lower surface of the tensile layer and the bottom surface of the cog valley is now Wmm, and the distance between the horizontal sagging layer 4 adjacent to the lower part of the tensile layer and the tensile layer and the bottom surface of the cog valley is approximately at the center. The diameter of the lateral sag layer 7 is D ₁ mm,
D ₁ , N 1 , D 2 , N ₂ so as to satisfy _0.20W < D ₁ N ₁ + D ₂ N ₂ < 0.45W when D ₂ mm and the number of plies are N ₁ and N _{2 ,} respectively. It is necessary to make a selection (Figure 2). Note that when the total thickness of the lateral sag layers 4 and 7 is less than 0.20W, the effect of lateral pressure resistance is small, while when the total thickness of the lateral sag layers 4 and 7 is 0.45W or more, the bending resistance decreases and the durability decreases. Since there is a problem that the sexual life is shortened, it is desirable to keep it within the above range. Further, it goes without saying that short fiber groups may be embedded in other rubber layers of the compressed portion 6 in a horizontal direction, if necessary. Next, the effects of implementing the variable speed V-belt with cogs according to the present invention will be explained. Belt top V width 35mm, thickness
There is a sag diameter on the lower surface of the tensile part of a variable speed V-belt with a cog of 15mm, V angle of 28°, belt outer circumference length of 1256mm.
D ₁ = 0.40mm, D ₂ = 0.68mm horizontal suda record 4,7
The cog-equipped transmission V of the present invention in which 2 plies of each are embedded
As shown in Fig. 3, the conventional cog-equipped variable speed V-belt B, which has two plies of belt A and horizontal sag 7 with a sag diameter of 0.68 mm buried in the compression part, is connected to the drive pulley.
Wrap around D _R and driven pulley D _N with center distance x of 350 mm, run at low speed under load condition of 20 p.s. (D _R type 90φ,
A running test was conducted in which one cycle was one cycle of D _N type 240φ, rotation speed 1750 rpm) for 20 seconds, and high speed running (D _R 170φ, D _N diameter 170φ, rotation speed 1750 rpm) for 60 seconds, and the wear amount on the belt upper width and belt appearance. The results were obtained as shown in Figure 4 and Table 1.

[Table] According to this result, the belt width wear margin is 1.05 mm at 2000 cycles in the conventional variable speed V-belt B, while the belt width wear margin is 1.05 mm at 3000 cycles in the variable speed V-belt A of the present invention.
When evaluated at the same number of cycles, the belt width wear allowance of the variable speed V-belt of the present invention is less than 1/2 of that of the conventional product, and there are no cracks visible on the belt appearance. It can be seen that this has been improved. (Effects of the Invention) As described above, the variable speed V-belt with V-shaped cogs of the present invention has two positions adjacent to the tensile rope layer in the compressed portion of the variable speed V-belt with cogs and one in the intermediate portion of the compressed portion.
~Bending resistance is achieved by embedding multiple layers of side sag through a rubber layer containing HRH and adjusting the total thickness of the sag in the compressed part to a range of 0.20 to 0.45 times the thickness of the compressed layer at the cog valley. It has excellent performance, with a marked reduction in top width wear during belt running, no cracking in the cog valleys, and good side pressure resistance, for use in automobiles, agricultural machinery, and other general industries. However, it is a suitable variable speed V-belt.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of the variable speed V-belt with cogs of the present invention, FIG. 2 is a partial side view of the variable speed V-belt with cogs of the present invention, and FIG. 3 is a schematic diagram of a running test device for confirming the implementation effect. FIG. 4 is a graph showing the running test results, and FIG. 5 is a partial side view showing an example of a conventional variable speed V-belt. a... Belt body, b... Cog portion, x... Center distance, 1... Tensile rope, 2... Cushion rubber layer, 3, 4, 7... Side sagging layer, 5... Elastic canvas , 6... Compressed rubber layer, 8... Bottom surface of the cog part,
9...HRH rubber layer.

Claims (1)

[Claims] 1. A variable speed V-belt with a cog, which has an extension part, a tensile body part, and a compression part in this order from the upper side, the extension part being composed of an elastic canvas and at least one layer of horizontal strap records, and the compression part having at least one layer on the lower side of the tension body part. It has one layer of lateral strut records, and further has at least one layer of lateral strut records at a position that approximately bisects the lowermost surface of the cog valley of the tensile rope layer;
These horizontal strut records are embedded in a wave shape with the same period as the cog waveform, with a rubber layer containing HPH interposed between each horizontal strut record layer, and the sum of the thickness of the horizontal strut record layers in the compression part is the tensile rope. A variable speed V-belt characterized in that the thickness is in the range of 0.20 to 0.45 times the thickness between the layer and the bottom surface of the cog valley.