JP3307265B2 - Toothed belt canvas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a canvas for a toothed belt such as a timing belt. More specifically, the present invention relates to a toothed belt canvas having improved abrasion resistance and water resistance.

[0002]

2. Description of the Related Art As shown in FIG. 1, a toothed belt for power transmission such as a timing belt has a backing rubber 1, a core wire 2,
It is composed of tooth rubber 3 and canvas 4. The core wire supports the tension for transmitting power, the back rubber and the tooth rubber support the transmission of force between the pulley and the core wire, and the canvas protects
Functions as a reinforcement. As shown in FIG. 1, the canvas covers the toothed side of the toothed belt, and a large load is applied. Therefore, various means for improving the wear resistance of the toothed belt to prevent chipping have been proposed. For example, JP-A-61-6593
No. 7 discloses that abrasion resistance is improved by incorporating a lubricating synthetic resin into canvas.

[0003]

On the other hand, besides the problem of tooth missing, the toothed belt also has a problem of cutting.
As shown in FIG. 2, the core wire shown in FIG. 1 is obtained by combining a plurality of glass fibers with resorcinol formaldehyde (RF) as a binder.
L), and each glass fiber is coated with a surface treatment agent (silane coupling agent) in order to enhance the adhesion to RFL. However, when water invades into the canvas, the invading water significantly degrades the treatment agent for the core wire, that is, the silane coupling agent, which is a reinforcing material for the belt, and as a result, the belt is cut. .

[0004] In order to solve this problem, it is conceivable to coat with waterproof rubber, but sufficient wear resistance cannot be obtained by coating with rubber. As described above, there is a problem that the conventional method cannot improve both the wear resistance and the water resistance.

[0005]

According to the first aspect of the present invention, the surface of a toothed belt canvas is coated with a thin film of diamond-like carbon. In a second aspect, in the first aspect, the diamond-like carbon thin film has a thickness of 2 to 5 μm. According to a third aspect of the present invention, in the method for producing a toothed belt canvas, a carbon source is plasma-sprayed on the surface of the canvas by extending the woven canvas by 30 to 50% from its original size. A thin film of diamond-like carbon is formed.

Since diamond-like carbon has a high hardness, the wear resistance of a toothed belt canvas is improved by coating the surface with such a diamond-like carbon thin film. Furthermore, since diamond-like carbon has hydrophobicity, the provision of this thin film imparts hydrophobicity to the toothed belt canvas, thereby improving the water resistance.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention is characterized in that the surface of a canvas for a toothed belt as shown in FIG. 1 is coated with a thin film of diamond-like carbon. The base fabric for applying the thin film of diamond-like carbon is usually used for a toothed belt,
Synthetic fibers such as cotton, nylon, polyester, and polyamide, or those woven from a blended yarn thereof can be used.

[0008] In the present invention, the diamond-like carbon has a diamond crystal structure in which 70% or more of carbon-carbon bonds are bonds by sp ³ hybrid orbitals. This diamond-like carbon thin film can be formed by various thin film forming methods such as a chemical vapor deposition (CVD) method and a plasma CV method.
D method, vacuum evaporation method (ion beam evaporation method, laser evaporation method), electrolytic plating method and the like can be used.

That is, for example, a hydrocarbon used in conventional synthesis of diamond, such as methane, ethane, acetylene, benzene, etc., is used as a carbon source, and the carbon source is activated by plasma in hydrogen and reacted. . This plasma is excited by a DC power supply, electromagnetic waves such as radio waves and microwaves, and the like. Alternatively, a laser beam may be pulsed and irradiated to generate plasma. The carbon ions in the plasma thus generated are fixed and crystallized on the base fabric to form a diamond-like carbon thin film.

The thickness of the diamond-like carbon thin film is preferably 2 to 5 μm. If the thickness is less than 2 μm, the desired effects, that is, the improvement of abrasion resistance and water resistance, cannot be obtained, and if the thickness is more than 5 μm, no further improvement can be obtained. This is because, on the contrary, it may deteriorate.

When forming the diamond-like carbon thin film, it is preferable that the carbon source is plasma-sprayed while the base cloth is stretched by 30 to 50%. By forming the thin film in a state where the base cloth is stretched by 30% or more, a thin film of diamond-like carbon can be formed on each of the yarns constituting the base cloth, and the inside of the base cloth can be formed. This is because a diamond-like carbon thin film can be formed up to and the diamond-like carbon thin film to be formed can be made discontinuous and cracking of this thin film can be suppressed. On the other hand, if the coating is formed in a state where the base fabric is stretched by more than 50%, carbon ions that pass through without attaching to the base fabric increase, which is not efficient and is not preferable. Therefore, it is preferable that the base fabric is woven from elastic yarn such as polyamide.

[0012]

EXAMPLE A canvas coated with a diamond-like carbon thin film was manufactured as shown in FIG. That is, the wooly yarn 9 and the covering yarn 10 were wound around a core yarn 8 made of industrial polyamide to form a stretchable warp yarn 11.
The warp yarn 11 and the weft yarn 12 made of industrial polyamide were knitted to produce a canvas 13. The diameter of each filament constituting this canvas was about 40 μm (44 denier).

In a state where the canvas thus manufactured is stretched by 45%, methane is used as a carbon source in a chamber at a degree of vacuum of 1 × 10 ⁻⁴ Torr, a DC voltage of 500 V and a DC current of 2.0 A.
Plasma spraying was performed for 45 minutes under the conditions described above to form a diamond-like carbon thin film having a thickness of 5.0 μm.

With respect to the canvas of the present invention thus obtained,
The abrasion resistance was measured as shown in FIG. That is, the above-mentioned canvas 15 of the present invention coated with a diamond-like carbon thin film was placed on the pedestal 14, and the steel pins 16 were placed on this canvas. An 8N load was applied to the pin 16, and the pedestal 14 was rotated at 100 rpm. The amount (volume) scraped off from the canvas 15 by the pin 16 was measured and defined as the amount of wear. For comparison, the same measurement was performed on a canvas (base fabric) not coated with a diamond-like carbon thin film. The result is shown in FIG. As is clear from the results of FIG. 5, the wear resistance of the canvas was greatly improved by coating the diamond-like carbon thin film.

Next, the water resistance of the canvas of the present invention was measured as shown in FIG. That is, the canvas 15 (30 mm in diameter) of the present invention was fixed to the lower part of the cylindrical container 17 with a holding plate (mesh) 18, and 500 ml of water was put into the container 17 at 80 ° C. Water 19 dripping from the lower part of the container 17
Collected for 10 minutes and allowed to pass. For comparison, a canvas (base fabric) which was not coated with a diamond-like carbon thin film in the same manner as above was measured in the same manner. The result is shown in FIG. As is clear from the results of FIG. 7, the water resistance of the canvas was greatly improved by coating the diamond-like carbon thin film.

[0016]

By coating the surface of the canvas with a thin film of diamond-like carbon, the abrasion resistance is improved and the hydrophobic property is imparted. As a result, water permeates through the canvas to the inner core wire. And water resistance of the canvas is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a toothed belt.

FIG. 2 is a cross-sectional view showing a structure of a cord.

FIG. 3 is a schematic view showing a structure of a canvas.

FIG. 4 is a schematic diagram of a wear resistance test of a canvas.

FIG. 5 is a graph showing the results of a wear resistance test.

FIG. 6 is a schematic diagram of a water resistance test of a canvas.

FIG. 7 is a graph showing the results of a water resistance test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Back rubber 2 ... Core wire 3 ... Tooth rubber 4 ... Canvas 5 ... Glass fiber 6 ... Silane coupling agent 7 ... RFL 8 ... Core wire 9 ... Woolly thread 10 ... Covering thread 11 ... Warp thread 12 ... Weft thread 13 ... Canvas 14 ... pedestal 15 ... canvas 16 ... pin 17 ... container 18 ... holding plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16G 1/00-9/04 D03D 1/00-27/18 H01L 21/312-21/475

Claims (3)

(57) [Claims] 1. A toothed belt canvas having a surface coated with a diamond-like carbon thin film. 2. The toothed belt canvas according to claim 1, wherein the diamond-like carbon thin film has a thickness of 2 to 5 μm. 3. The woven canvas is reduced by 30 to 50 from its original size.
2. The method for producing a toothed belt canvas according to claim 1, wherein a diamond-like carbon thin film is formed on the surface of the canvas by plasma spraying a carbon source in a state in which the carbon fiber is stretched in a% ratio.