JPS5965644A - Toothed belt - Google Patents

Abstract

PURPOSE:To improve durability of a toothed belt, in which a wear resistant reinforcing material having high hardness or high elasticity is placed to be mixed in internal and external surfaces of a reinforced canvas layer, by improving wear resistance of the toothed belt, rigidity and strength of its tooth part. CONSTITUTION:A toothed belt consists of a tensile member 1 having a high elastic modulus such as glass fiber and steel wire, upper part rubber layer 2 and a tooth part rubber layer 3, using an elastic material such as chloroprene rubber or the like forming a belt shape. A reinforced adhesive rubber layer 4, in which a wear resistant reinforcing material 6 having high hardness or high elasticity is placed to be mixed, is arranged on internal and external surfaces of a canvas 5a of low friction coefficient of nylon or the like coating a surface of the tooth part rubber layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a toothed belt in which the tooth surfaces of the toothed portions are covered with a reinforcing canvas layer.

Conventional toothed belts, especially toothed belts with a standard trapezoidal tooth profile, lack the strength of the teeth compared to the belt strength. It is extremely rare for the tensile member, that is, the belt itself, to be damaged, and this is a cause of shortening the service life.

In view of this, the means to improve the strength of the tooth section are: 1) Improving the tooth rigidity to improve shear fatigue strength, 2) Improving the tooth wear resistance and reducing tooth wear. (2) Improving the shape of the teeth in the tooth portion to distribute and even out stress to prevent stress concentration and improve fatigue resistance.

However, regarding item (2) above, since the teeth are formed of an elastic body, even if the shape of the teeth is specified, the shape changes depending on the load, making it difficult to obtain a sufficient improvement effect.

Therefore, we focused on the above point (■) and developed a technology to improve the wear resistance of the teeth and increase the strength of the teeth.
/7 As shown in Publication Otsu, a toothed belt using a wear-resistant canvas having self-lubricating properties, that is, a rubber mixture in which a lubricant such as graphite is added to the woven grooves on the tooth side surface of the canvas. A painter's belt has been proposed using canvas filled with.

In other words, in this proposed toothed belt, when the canvas is subjected to friction due to contact with the pulley while running, a lubricant such as graphite, which is rubbed into the canvas weave grooves together with rubber, is supplied to the contact surface, and the contact surface is It prevents the canvas from wearing out by keeping the coefficient of friction at a low level.

However, although the proposed toothed belt has a structure that improves the wear resistance of the teeth in (2), it does not have any positive effect on the rigidity of the teeth in (2), and it also has a structure that improves the wear resistance of the teeth (2). When graphite is used as an agent, its high-temperature stability decreases, so the lubricating effect decreases slightly in a high-temperature atmosphere ((S>θ°C or higher), and the effect of improving wear resistance cannot be obtained sufficiently. Furthermore, since the canvas is required to have a large number of woven grooves, the weaving structure is limited and the canvas that can be used is limited.

In view of this, the present invention mixes abrasion-resistant reinforcing material with high hardness or high elasticity on the inner and outer surfaces of the reinforcing canvas layer that covers the tooth surfaces of the teeth, and furthermore, the inner surface of the reinforcing canvas layer. A reinforcing adhesive rubber layer mixed with a reinforcing material is provided to provide a toothed belt that improves the wear resistance of the teeth and also improves the rigidity of the teeth to increase the strength of the teeth. improved 5
The purpose is to improve the durability of the belt.

Hereinafter, an example of "misfire" will be described with reference to the drawings.

In the toothed belt having standard trapezoidal teeth as shown in FIG. 1, an upper rubber layer and a toothed rubber layer made of an elastic material such as chloroprene rubber, which protect the belt and form the belt shape; An adhesive rubber layer, and a canvas 5 with a low friction coefficient such as nylon to protect the tooth surface.
This is a reinforced canvas layer in which a reinforcing material 6 is mixed inside.

The reinforcing adhesive rubber layer 4 provided at the adhesive interface between the tooth rubber layer 6 and the reinforcing canvas layer 5 is for firmly adhering the tooth rubber layer 6 and the reinforcing canvas layer 5 to each other. As shown in the figure, a reinforcing material 6 is mixed in the adhesive rubber.

In addition, the reinforced canvas layer 5 includes a canvas 5a woven with mutually perpendicular weft and warp yarns, and a mixture containing a reinforcing material 6 similar to that of the reinforced adhesive rubber layer 4 is impregnated and coated on the inner and outer surfaces of the canvas 5a. has been done.

The reinforcing material 6 is made of a material that is extremely elastic, highly elastic, and has excellent abrasion resistance, such as carbon fiber, aramid, ultrahard metal, etc., and is formed into short fibers or particles. use In the case of short fibers, the filament diameter is /~/θμ, and the aspect ratio (length/
It is preferable that the particles have a diameter of 3 to /j, and in the case of particles, those with a particle diameter of 6-jθμ are preferable. Further, in any shape, the mixing ratio with the adhesive rubber is within the range of 70 to 60% by weight.

The material, shape, mixing ratio, etc. of the reinforcing material 6 may be changed between the reinforcing adhesive rubber layer 4 and the reinforcing canvas layer 5.

In addition, inclusions present on the surface of the canvas 5a in the reinforcing canvas layer 5 are made to completely cover the entire surface or partially cover the surface, but in order to improve abrasion resistance, it is necessary to cover the entire surface. is preferred. In addition, the adhesive rubber in the mixed material is slightly different in composition, viscosity, etc. for the reinforcing adhesive rubber layer 4 and the reinforcing canvas layer 5 based on the difference in the formation method, but the same material is used. Alternatively, it may be the same as the tooth rubber layer 3. Further, the canvas 5a of the reinforced canvas layer 5 is usually made of twill weave that has elasticity between one side, but it is not limited to this.
Any weave configuration may be used.

A preferred embodiment of the reinforcing material B mixed in the mixture used for the reinforcing adhesive rubber layer 4 and the reinforcing canvas layer 5 will be shown below.

Material: Carbon fiber Shape: Short fibrous Filament diameter: 3μ Aspect ratio: /θ Mixing ratio: 30% About manufacturing toothed belts like the one above.

The reinforcing adhesive rubber layer 4 and the reinforcing canvas layer 5 are preferably formed by the following processing method.

A known adhesive rubber based on mass or chloroprene is dissolved in a solvent such as toluene (/: /) to form a paste, and the reinforcing material 6 is added to the mixture at a mixing ratio of 10 to jθ%. , stir thoroughly to obtain a first mixture. This first inclusion is further diluted with a solvent to a dilution ratio of 2 to 3 to obtain a second inclusion.

Subsequently, the untreated 5d original canvas was soaked in the second mixture,
The canvas 5a is impregnated with a rubber mixture. After repeating this process several times and drying appropriately, the first inclusion is rubberized to a predetermined thickness on the adhesive surface (inner surface) side of the canvas 5a to obtain a treated canvas.

A toothed belt is manufactured using the above-mentioned treated canvas according to the following procedure.

First, the above-mentioned treated canvas is cut into a predetermined size, and this is cut into a canvas by sewing, heat welding, adhesive, etc.
Finish it into a cylindrical shape so that the elastic direction of a is the circumferential direction, and insert it into a mold with tooth profiles on the outer surface, or
The canvas 5a is wrapped around the surface of the mold, and the edges of the canvas are fixed with adhesive or the like.

Seven to two tensile members 1 made of glass fiber, steel wire, aromatic aramid, etc. are wound spirally onto the canvas 5a. For the winding, a close pitch of about /, / to 2.0 of the cord diameter is adopted. Seven or two layers of rubber sheets forming the tooth rubber layer 6 and the upper rubber layer 2 are wound on top of this, vulcanized using a known vulcanizing can under predetermined conditions, and removed from the mold. Cut into a belt shape to obtain a toothed belt.

As in the above embodiment, since the reinforcing material 6 such as carbon fiber is mixed in the reinforcing canvas layer 5 and the reinforcing adhesive rubber layer 4, the following reinforcing effect can be obtained.

Basically, the reinforcing canvas layer 5 that covers the toothed surface of the toothed belt
The canvas 5al protects the teeth from being worn out due to sliding contact with the pulley or meshing interference, and using O-Otsu nylon as the canvas material has a somewhat lubricating effect.

In addition, since the reinforcing material 6 is mixed in the reinforcing canvas layer 5, when the toothed belt is subjected to some degree of wear and tear due to contact with the pulley, the contact surface of the teeth is protected by adhesive rubber. A large number of reinforcing materials 6 appear in the vertical shape and prevent their wear.

In addition, a reinforcing material 6 is added to the reinforcing canvas layer 5 and the reinforcing adhesive rubber layer 4.
By mixing these, the rigidity of the tooth part as a composite is increased, and when the tooth part meshes with the pulley, the deformation due to bending and shearing from the pulley is reduced, improving shear fatigue strength and increasing durability. Improved.

Next, test results confirming the effects of the present invention will be explained.

FIG. 3 shows the comparison results of a tooth canvas wear test conducted on the toothed belt of the present invention and the conventional belt under the following running conditions. In addition, the canvas wear residual rate in FIG. 3 indicates the ratio of the tooth surface canvas thickness after the belt runs to the tooth surface canvas thickness before the belt travel, and the canvas thickness is measured using an industrial microscope.

Test conditions Belt tooth profile, pitch = ZA type, 6.26 w
□Belt width, number of teeth Near 2. θmm, 5i' 6
Tooth ambient temperature 2 20℃ Driven shaft load power: ), jPs drive shaft rotation speed
: Otsu, θθθrpm Belt initial tension:
, 2. fkgf As is clear from Fig. 3, the toothed belt of the present invention has better wear resistance than the conventional belt! ~3
It has improved twice as much.

Figure 7 shows the results of a comparative test regarding the shear fatigue strength of toothed belts in which a load durability test was conducted on a toothed belt under the same running conditions as the canvas abrasion test but with varying load power. . Note that the durability life in FIG. 7 is the running time until the teeth of the toothed belt are damaged by shearing.

As is clear from FIG. 7, the toothed belt of the present invention has a durable life of /6.5 to 6.5% compared to the conventional belt. This is an improvement of 2.0 times.

As explained above, according to the toothed belt of the present invention, by mixing the wear-resistant reinforcing material on the inner and outer surfaces of the canvas of the reinforcing canvas layer, the wear resistance of the tooth surface is improved, and the tooth It is possible to improve strength by reducing part wear, and
By mixing reinforcing materials in the reinforced canvas layer and the reinforced bonded rubber layer, the rigidity of the teeth can be improved, improving the strength of the overall curved tooth portion and greatly improving the durability of the belt. It is something to do.

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention, and FIG. 7 is a longitudinal sectional view of a toothed belt, FIG. 2 is an enlarged sectional view of the main part within the chain line circle in FIG. 1, and FIG. 3 is a toothed canvas. A graph showing the results of the wear test, and FIG. 7 is a graph showing the results of the tooth shear fatigue test. 1... Tensile body, 2... Upper rubber layer, 6...
・Tooth rubber layer, 4...Reinforcement adhesive rubber layer, 5...
... Reinforced canvas layer, 5a... Canvas, 6...
・Reinforcement material (11) Habit 1 Figure 2nd day [@l. ] n'! uWl&'M+IQI H*>
−[:5eI)σ4 sealed

Claims (2)

[Claims] (1) In a toothed belt that has teeth and the tooth surfaces of the teeth are covered with a reinforcing canvas layer, the reinforcing canvas layer has high hardness or high elasticity and wear resistance on the inside of the canvas and on the outer surface of the canvas. A toothed belt characterized in that a reinforcing material is mixed therein, and a reinforcing adhesive rubber layer made of a reinforcing material mixed therein is provided on the inner surface of the reinforcing canvas layer. (2) The tooth (-1 belt) according to claim 1, wherein the wear-resistant reinforcing material is short carbon fiber.