JPH0242344B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Field of Application) The present invention relates to a method for manufacturing a ribbed V-belt in which a plurality of ribs (projections) are provided protruding from a belt base belt in the longitudinal direction of the belt. (Prior Art) Generally, a ribbed V-belt is known in which a plurality of ribs are provided protruding from a belt base belt in the longitudinal direction of the belt. Such a ribbed V-belt is
As a transmission belt, for example, a small diameter rib groove pulley and a large diameter flat pulley (drum) are used in a domestic dryer.
It is used by winding it around. The above-mentioned ribbed V-belt is usually manufactured only from rubber without covering the ribs with canvas, since it is difficult for the ribs to protrude if canvas is attached to the outer surface of the ribs. (Problem to be Solved by the Invention) Therefore, when used in a household dryer as described above, the friction coefficient of the side surface of the rib becomes large, and the friction coefficient at the time of startup and stop (overload), and when the temperature is 0°C.
There is a problem that abnormal noises are generated during the winter when the belt has been running for more than 50 hours.
In addition, a technique is known to reduce the coefficient of friction by mixing short fibers into the ribs, but this reduces flexibility, so if the small diameter ribs and groove pulleys have a small radius of curvature and are repeatedly engaged in a bent state, , another problem is premature cracking of the ribs. In addition, in Japanese Patent Publication No. 42-2066, a ribbed V-belt is proposed in which fiber waste consisting of fine, dense, and short fibers is deposited and adhered to the outer surface of the rib instead of canvas. It is difficult to uniformly attach fibers to the surface, which poses a quality problem, and requires a large number of manufacturing steps, resulting in high costs. An object of the present invention is to provide a method for manufacturing a ribbed V-belt that can prevent the generation of abnormal noise. (Means for Solving the Problems) The present invention relates to an improvement in a method for manufacturing a belt in which a plurality of ribs are provided protruding from a belt base band along the belt longitudinal direction. Therefore, the manufacturing method of the present invention includes a canvas, an unvulcanized rubber sheet, a tensile member, another unvulcanized rubber sheet, and a friction coefficient reducing agent on the outer peripheral surface of a rubber sleeve fitted onto a molding die. A cylindrical unvulcanized molded body is formed by sequentially winding a nonwoven fabric or nonwoven paper impregnated with It is characterized in that vulcanization molding is carried out by applying the nonwoven fabric or nonwoven paper to a vulcanization mold having rib grooves so that the nonwoven fabric or paper faces the rib grooves. The above-mentioned nonwoven fabric or paper may be a single synthetic fiber, an artificial fiber, or a natural fiber such as polyester, polyamide, rayon, vinylon, cellulose, or pulp, or a blend thereof. Its thickness is about 0.01 to 0.03mm, and the unit weight (fabric weight)
is 3 to 100 g/ ^m2 . As the friction coefficient lowering agent, graphite,
Molybdenum disulfide, fluororesin powder, etc. are used. When using graphite, the rubber component
It is desirable to directly impregnate a nonwoven fabric or paper with 1 to 30 parts by weight of graphite per 100 parts by weight, or to indirectly impregnate it by coating. (Function) A canvas, an unvulcanized rubber sheet, a tensile material, another unvulcanized rubber sheet, and a nonwoven fabric impregnated with a friction coefficient reducing agent or A cylindrical unvulcanized molded body is formed by sequentially winding the nonwoven paper. Thereafter, the unvulcanized molded body is removed from the mold and the rubber sleeve. Vulcanization is performed by applying the unvulcanized molded article to a vulcanization mold having rib grooves so that the nonwoven fabric or paper faces the rib grooves. (Example) Examples of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a ribbed V-belt manufactured by the manufacturing method of the present invention, in which a plurality of ribs 3 are provided protruding from a belt base band 2 along the belt longitudinal direction. 4 is an upper canvas layer, which is made of, for example, two layers of cotton canvas. 5 is a tensile material layer, in which a tensile material cord 6 (e.g., polyester cord, glass cord, aromatic polyamide cord, etc.) is coated with adhesive rubber 7 (e.g., natural rubber, chloroprene rubber, styrene-natadiene rubber, isoprene rubber, nitrile-butadiene rubber). , or their blend rubber). A rib rubber layer 8 is made of, for example, natural rubber, chloroprene rubber, styrene-natadiene rubber, isoprene rubber, nitrile-butadiene rubber, or a blend thereof, and a portion thereof forms the rib 3. Reference numeral 9 denotes a uniform density surface layer made of nonwoven fabric or nonwoven paper, and is provided on the outer surface of the rib 3. This nonwoven fabric is impregnated with graphite as a friction coefficient reducing agent. Next, a method for manufacturing the ribbed V-belt 1 will be explained. (i) Step 1 First, a cylindrical rubber sleeve 12 is fitted onto the outside of a molding die 11 in the same manner as in the conventionally known molding method of a ribbed V-belt. (ii) Step 2 Cotton canvas 4a, which will become the upper canvas layer 4, and adhesive rubber 7 are placed on the outer peripheral surface of the rubber sleeve 12 fitted in Step 1.
A relatively thin unvulcanized rubber sheet 13 that will become the tension body cord 6 and another relatively thick unvulcanized rubber sheet 14 that will become the rib rubber layer 8 are wound in order.
Thereafter, a non-woven fabric 15 containing graphite, which will become the surface layer 9, is wound thereon in the longitudinal direction (circumferential direction) of the belt to form an unvulcanized molded body 16 (see FIG. 2). (iii) Step 3 After completion of molding in Step 2, the unvulcanized molded body 16 is removed from the molding die 11 along with the rubber sleeve 12, and then the unvulcanized molded body 16 is removed from the rubber sleeve 12. (iv) Step 4 As shown in FIG. 3, for a cylindrical vulcanization mold 17 with rib grooves 17a formed on the inner peripheral surface, the nonwoven fabric 15 of the unvulcanized molded body 16 faces the rib grooves 17a. Insert the unvulcanized molded body 16 as shown in FIG.
apply. Then, heat and pressure are applied from the inside of the vulcanized sleeve 18 by heating and pressing to cause the ribs to protrude as shown in FIG. 4, thereby vulcanizing the entire belt. In this case, the nonwoven fabric 15 does not hinder the protruding deformation of the ribs, unlike a strong woven canvas. (v) Step 5 Cylindrical vulcanized body 1 vulcanized in Step 4
9 from the vulcanized sleeve 18, cut the width to the desired number of ribs, and create the desired ribbed V.
Obtain Belt 1. Next, the ribbed V-belt 1 of the present invention example (see FIG. 1) and the ribbed V-belts 21, 22, 23 of the first, second, and third comparative examples (FIGS. 5, 6, and 7) We will explain the tests conducted on (see figure). Test Belt The ribbed V-belt 21 of the first comparative example differs from the ribbed V-belt 1 of the invention example in that it does not include the surface layer 9. Ribbed V-belt 22 of second comparative example
The ribbed V-belt 1 of the example of the present invention has a surface layer 9
The difference is that polyamide fibers 25 (2 denier, 1 mm cut) are mixed in the rib rubber layer 24 at a volume content of 8%.
The ribbed V-belt 23 of the third comparative example differs from the ribbed V-belt 1 of the invention example in that the nonwoven fabric forming the surface layer 26 does not contain graphite as a friction coefficient lowering agent. The dimensions are L ₁ = 4.8 mm, L ₂ = 2.3 mm, L ₃ = 2.0 mm in Fig. 1, Fig. 5, Fig. 6, and Fig. 7.
L ₄ = 0.97mm, L ₅ = 1.6mm, θ = 40°, total belt length is
It is 2210mm and has three ribs. The nonwoven fabric used for the surface layer of the ribbed V-belts 23, 1 of the third comparative example and the present invention example was made of mixed fibers of pulp and rayon (15% by weight of pulp, 85% by weight of rayon), and had a unit weight of 14 g/ ^m2 , and the nonwoven fabric used for the surface layer of the ribbed V-belt 1 of the example of the present invention has a rubber component.
It is impregnated with 5 parts by weight of graphite per 100 parts by weight. Test method (i) Abnormal noise test A dryer having the drive system shown in Figure 8 was used. That is, drum 41 (diameter 600 mm),
Motor pulley 42 (diameter 17mm, rotation speed
1650rpm) and fan pulley 43 (diameter 10
Wrap the test belt 44 around the idler pulleys 45 and 46 (diameter 40 mm),
I ran it with a load of Kgf. However, after running for 50 hours, it was returned to a room with a room temperature of 5℃.
After leaving it for 15 hours, the occurrence of abnormal noises at startup and stop was investigated. (ii) Friction coefficient measurement test As shown in Fig. 9, the test belt 53 is wound around the drive pulley 52 (diameter 14 mm, rotation speed 72 rpm) from the load cell 51 at an angle α (rad), and dead weight DW ₁ = 1.75. Added Kgf. Thus, the measured value T of the load cell 51 was measured, and the friction coefficient μ was calculated from μ=ln(T/DW ₁ )/α. (iii) Wear test As shown in Figure 10, flat pulley 61 (diameter
40 mm) and a rib grooved pulley 62 (diameter 14 mm, rotation speed 4800 rpm), and a dead weight DW ₂ = 18 on the flat pulley 61.
After running for 24 hours with Kgf added, the amount of wear was measured. Amount of wear = {(Initial weight) - (Weight after 24 hours of running)}/(
(rib rubber specific gravity) (iv) Multi-axis bending test As shown in Figure 11, six flat pulleys 71
(diameter 76 mm), driving side rib groove pulley 72 (diameter 16.5 mm, rotation speed 1780 rpm), and six driven side rib groove pulleys 73 (diameter 16.5 mm). A dead weight DW ₃ =13.5 Kgf was added, the test piece was run in that state, and the time until cracks appeared in the ribs was measured, which was determined as the bending life. Test results The test results are shown in the table below.

[Table] However, regarding the presence or absence of abnormal noises, an x mark indicates that there is a strange noise when starting and stopping, a △ mark indicates a slight abnormal noise, and an ○ mark indicates that there is no abnormal noise. Further, the friction coefficient μ was set to 100 based on the first comparative example, and was expressed as an index. Therefore, from the above test results, the rib surface is
Nonwoven fabric (or nonwoven paper) containing graphite
By configuring the
As a result, dryers and the like can smoothly slip when starting and stopping (when overloaded), thereby eliminating abnormal noise. Furthermore, by forming the rib surface with a nonwoven fabric (or nonwoven paper) containing graphite, the wear resistance can be significantly improved. The ribbed V-belt manufactured by the manufacturing method of the present invention can be used not only for the above-mentioned dryer but also for various purposes such as driving auxiliary equipment in automobiles and washing machines. (Effects of the Invention) In the present invention, the nonwoven fabric or nonwoven paper serving as the surface layer of the rib is vulcanized and molded so as to face the rib groove. is done easily, has good formability, and has ribbed V
The belt can be manufactured easily. In addition, since the surface layer of the rib is made of nonwoven fabric or paper impregnated with a friction coefficient reducing agent, the friction coefficient is greatly reduced without impairing flexibility, and noise is prevented. , a ribbed V-belt with improved wear resistance can be easily produced.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an example of a ribbed V-belt manufactured by the manufacturing method of the present invention, and FIGS. 2 to 4 are illustrations of a method of manufacturing a ribbed V-belt according to an embodiment of the present invention. 5 is a longitudinal sectional view of a ribbed V-belt of a first comparative example, FIG. 6 is a longitudinal sectional view of a ribbed V-belt of a second comparative example, and FIG. 7 is a longitudinal sectional view of a ribbed V-belt of a third comparative example. A vertical cross-sectional view of the belt, Figure 8 is an explanatory diagram of the system used for the noise test, Figure 9 is an explanatory diagram of the system used for the friction coefficient measurement test, and Figure 10 is an explanatory diagram of the system used for the wear test. , FIG. 11 is an explanatory diagram of the system used for the multiaxial bending test. 1... Ribbed V-belt, 2... Belt base band, 3
... Rib, 4a ... Cotton canvas, 6 ... Tensile cord, 11 ... Molding mold, 12 ... Rubber sleeve,
13, 14... Unvulcanized rubber sheet, 15... Nonwoven fabric, 16... Unvulcanized molded body, 17... Vulcanized mold,
17a...Rib groove.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a belt in which a plurality of ribs are provided protruding from a belt base band along the belt longitudinal direction, comprising: on the outer circumferential surface of a rubber sleeve externally fitted in a molding die; A canvas, an unvulcanized rubber sheet, a tensile material, another unvulcanized rubber sheet, and a nonwoven fabric or paper impregnated with a friction coefficient reducing agent are wound in order to form a cylindrical unvulcanized molded body, Thereafter, the unvulcanized molded body is removed from the molding die and the rubber sleeve, and the unvulcanized molded body is placed against a vulcanization mold having rib grooves so that the nonwoven fabric or nonwoven paper faces the rib grooves. 1. A method for manufacturing a ribbed V-belt, the method comprising applying and vulcanization molding. 2. The friction coefficient lowering agent is graphite, and the nonwoven fabric or paper is impregnated with 1 to 30 parts by weight of graphite per 100 parts by weight of the rubber component, as described in claim 1. Ribbed V
Belt manufacturing method.