JP4634986B2 - Transmission flat belt - Google Patents

Description

  The present invention relates to a transmission flat belt, and more particularly to a transmission flat belt having a transmission surface in which at least one of an inner surface side and a rear surface side is formed by a cover rubber layer and the surface is formed flat.

A transmission flat belt widely used as a power transmission means in the industry is always used in a form that causes a micro-slip (elastic slip) because the power transmission form is a frictional transmission. Therefore, when power is transmitted, heat is generated due to friction.
In general, since the transmission flat belt is formed of a rubber material, dynamic heat is generated during operation.
Further, such a transmission flat belt is used in the vicinity of an engine or the like as described in Patent Document 1, for example, and is generally used in a high temperature environment.

In this way, the transmission flat belt is used in an environment that is susceptible to thermal degradation, while the transmission flat belt is unable to transmit power due to, for example, slipping or breaking. Has a risk of seriously damaging the equipment itself in which the transmission flat belt is used. Therefore, conventionally, a transmission flat belt that can be used for a long period of time has been demanded.
For example, in Patent Document 1 described below, it is described that uneven wear of the transmission flat belt is prevented by adjusting the positional relationship of the transmission flat belt with respect to the pulley, thereby extending the belt life.

  However, the conventional transmission flat belt has not been adequately addressed, and has a problem that it is difficult to obtain a transmission flat belt that can be used for a long time.

JP 2006-9857 A

  The subject of this invention is providing the transmission flat belt which can be used for a long term.

The present inventor has found that at least one of the inner surface side and the rear surface side is formed of a cover rubber layer and the surface is formed flat, and the flat surface is a cause of occurrence of slip in the transmission flat belt used for the friction transmission. As a result of intensive studies on the countermeasures, it was found that the rubber of the cover rubber layer deteriorates with the passage of the use period of the transmission flat belt, and the warpage occurs in the belt width direction of the transmission flat belt. .
In addition, this warp causes a deviation in contact with the pulley.For example, when a warp in the belt width direction is formed such that the transmission surface is on the inner side, both ends in the belt width direction are more than the center part. As a result, the belt is strongly brought into contact with the pulley, and as a result, slippage is easily generated in the transmission flat belt, and it is found that the warpage can be suppressed by providing the cover rubber layer with a predetermined structure. It arrived at.

  That is, in order to solve the above-mentioned problem, the present invention is formed in an endless belt shape so as to be spanned by a plurality of pulleys and used for friction transmission, and at least one of the inner surface side and the rear surface side is formed by a cover rubber layer and The surface is formed flat, and the flat surface is a transmission flat belt used for the friction transmission, and the flat surface is formed with a cut extending along the circumferential direction of the belt. In addition, the transmission flat belt is characterized in that the cut is formed in a state of being cut into the cover rubber layer from the surface of the flat surface.

  In this specification, the “cut” is not formed by grinding or cutting the surface of the transmission surface such as a groove or a notch to remove a member that forms the surface. It is intended to be a part that is formed by being cut off only by entering, and in the natural state where no tension is applied, it is not opened on the surface, and this “cut” extends. It is intended to be formed so as to be opened when tension is applied in the direction perpendicular to the direction, that is, in the belt width direction.

  According to the present invention, the surface used for friction transmission is formed with a cut extending along the belt circumferential direction of the transmission flat belt, and the cut is formed from the surface of the friction transmission surface to the cover rubber layer. Therefore, even if the rubber of the cover rubber layer deteriorates and the surface contracts, the surface contraction is propagated in the belt width direction by this incision. In addition, it is possible to suppress this contraction force and cut off the contraction force at the cut forming portion.

Therefore, it is possible to suppress the occurrence of warpage in the belt width direction of the transmission flat belt.
Even if warpage occurs, the notch is formed, so that, for example, the tension applied to the belt is slightly increased. Can be brought into contact with the pulley.
That is, the occurrence of uneven wear on the transmission flat belt can be suppressed, and the belt life can be prolonged.

  Hereinafter, preferred embodiments of the present invention will be described (based on the accompanying drawings).

The transmission flat belt according to this embodiment is formed in an endless belt shape, and FIG. 1 is a partial cross-sectional view showing a cross section when the transmission flat belt is cut so as to cross the width direction.
As shown in FIG. 1, the transmission flat belt 10 has an adhesive rubber layer 12 in which a plurality of core wires 11 are embedded along the longitudinal direction of the belt, and is formed at the center in the belt thickness direction. Further, as shown in FIG. 1, a rubber coat canvas layer 14b is formed on the outer surface side of the adhesive rubber layer 12 via an intermediate rubber layer 14a, and the adhesive rubber layer 12 is formed on the inner surface side of the adhesive rubber layer 12. The inner cover rubber layer 13 bonded along the inner side is formed, and these are laminated in layers to form the transmission flat belt 10.

In the transmission flat belt 10 according to the present embodiment, the inner peripheral surface formed by the inner cover rubber layer 13 so that both surfaces of the rubber coated canvas layer 14b and the inner cover rubber layer 13 are used as friction transmission surfaces. The (inner surface side) is also formed to be a flat flat surface in the same manner as the outer peripheral surface formed by the rubber-coated canvas layer 14b.
The inner peripheral surface is continuously provided with a cut C having a depth that is about half of the depth from the surface to the core wire 11 along the belt circumferential direction.
FIG. 2 is a plan view showing a front view from the inner surface side where the transmission flat belt 10 is cut and formed with a cut C. FIG.
As shown in FIG. 2, the cuts C formed along the belt circumferential direction are formed in a continuous state in the circumferential direction, and the individual cuts C are included in the transmission flat belt 10. It is formed in a continuous circumferential shape so as to go around the peripheral surface and return to the original position.
Further, in the transmission flat belt 10 of the present embodiment, a plurality of strips of this circumferential cut C are formed at a pitch (P) at intervals of 3 to 6 times the cut depth (D ₁ ) in the belt width direction. ing.

With respect to the notch C, the depth (D ₁ ) in the belt thickness direction is usually the depth (D ₀ ) from the surface of the transmission surface to the core wire 11, that is, the thickness of the inner cover rubber layer 13 or less. It is formed to become.
It is to be noted that the depth of the incision (in the point that the warpage in the belt width direction of the transmission flat belt 10 can be suppressed, and even if the warp occurs, the warp can be more easily corrected. D ₁ ) is preferably a depth of ¼ or more of the thickness (D ₀ ) of the inner cover rubber layer 13, and more preferably a depth of ½ or more.
Further, the pitch (P) at which the cuts C are formed in the belt width direction is not particularly limited. If the pitch (P) is too small, a transmission flat belt is used. 10 may decrease in rigidity, and if the pitch is too large, warp may occur between the cuts C no matter how much the depth (D ₁ ) of the cuts C is increased. .
In this respect, the pitch (P) forming the cut C is selected from a range that satisfies the relationship of P / D ₁ = 2.5 to 25 with respect to the depth (D ₁ ) of the cut C. It is preferable.

By providing such a cut C, as shown in FIG. 3, when the inner cover rubber layer shrinks, the cut becomes an open state on the transmission surface, and the shrinkage is reduced. Propagation in the belt width direction is suppressed.
As a result, the warpage of the transmission flat belt in the belt width direction is suppressed.

The material of the core wire 11 used for the transmission flat belt 10 as described above is not particularly limited, but polyester fiber using polyester such as polyethylene naphthalate, aramid fiber, polyamide fiber, Examples include high-strength polyvinyl alcohol fiber and polyketone fiber.
These fibers can be used alone or as a mixture for the core wire 11.
The cord 11 may be one that has been subjected to a resorcin / formalin / latex treatment (hereinafter also referred to as “RFL treatment”) or a solvent-based adhesive.

  The rubber material of the adhesive rubber layer 12 is not particularly limited, but chloroprene rubber (CR), ethylene propylene diene monomer (EPDM), hydrogenated nitrile rubber (H-NBR), alkylated chlorosulfonated polyethylene ( ACSM) and the like, and a mixture of one or more of them can be used.

  The rubber material of the inner cover rubber layer 13 and the intermediate rubber layer 14a is not particularly limited, but chloroprene rubber (CR), ethylene propylene diene monomer (EPDM), hydrogenated nitrile rubber (H-NBR), alkyl Chlorosulfonated polyethylene (ACSM) and the like can be used, and those obtained by mixing one or more of them can be used.

  The rubber-coated canvas layer 14b is made of chloroprene rubber (CR), ethylene propylene diene monomer (EPDM), hydrogen with respect to a canvas using polyester fiber, aramid fiber, polyamide fiber, high-strength polyvinyl alcohol fiber, polyketone fiber and the like. The rubber material may be supported on the canvas by coating a nitrile rubber (H-NBR), an alkylated chlorosulfonated polyethylene (ACSM), or the like.

In addition to the rubber, the rubber material of the inner cover rubber layer 13, the intermediate rubber layer 14a, and the rubber coated canvas layer 14b can appropriately contain additives such as short fibers and fillers.
Examples of short fibers include organic polymer fibers such as polyester short fibers, polyamide short fibers, aramid short fibers, and cellulose short fibers, and inorganic fibers such as silicon carbide and potassium titanate. What mixed the seed | species or more can be used.
In addition, the short fiber contained in the transmission flat belt 10 of the present invention means a fiber having a fiber diameter of 5 to 40 μm and a fiber length of 0.1 to 10 mm.

  In addition to the above components, crosslinking agents, crosslinking aids, reinforcing components such as carbon black and silica, fillers such as calcium carbonate and talc, plasticizers, stabilizers, processing aids, colorants, etc. In addition, a rubber compounding agent used also in the rubber industry can be compounded within a range not impairing the effects of the present invention.

Next, a method for manufacturing the transmission flat belt 10 as described above will be described.
First, in the manufacture of the transmission flat belt 10, an unvulcanized rubber sheet for forming the adhesive rubber layer 12, the inner cover rubber layer 13, and the intermediate rubber layer 14a, the core wire 11 subjected to RFL treatment, Use rubber-coated canvas.

  For the unvulcanized rubber sheet of the adhesive rubber layer 12, the inner cover rubber layer 13, and the intermediate rubber layer 14a, the material contained in the rubber composition is mixed with a kneading means such as a general kneading roll, kneader or mixer. After kneading and kneading, the sheet can be formed with a calender roll or the like.

The transmission flat belt 10 is manufactured using such an unvulcanized rubber sheet of the adhesive rubber layer 12, the inner cover rubber layer 13, and the intermediate rubber layer 14a, the core wire 11 subjected to the RFL treatment, and the rubber-coated canvas. In order to achieve this, it can be produced in the same manner as a conventional method.
For example, a rubber-coated canvas, an unvulcanized rubber sheet for the intermediate rubber layer 14a, and an unvulcanized rubber sheet for the adhesive rubber layer 12 are wound on one or more layers around the peripheral surface of a cylindrical molding drum having a smooth surface. A core body 11 is spun into a spiral shape, and further, an unvulcanized rubber sheet for the adhesive rubber layer 12 and an unvulcanized rubber sheet for the inner cover rubber layer 13 are wound in one layer or a plurality of layers to form an unvulcanized laminate. Is made.

The laminated body in the unvulcanized state thus produced is, for example, heated and pressed in a vulcanizing can to be integrated to form a tubular body, and then cut out from the tubular body with a predetermined width to transmit a flat belt 10 for transmission. It can be.
At this time, since the tubular body is manufactured as described above, the inner cover rubber layer 13 is exposed on the outer peripheral surface side.
Therefore, for example, the plurality of blades arranged at a predetermined interval are brought into contact with the outer peripheral surface that is moved around while the tubular body is wound around the drive roll and the driven roll, thereby being moved along the belt circumferential direction. A cut can be formed in the extended state.
Further, the cut is formed in a state of being cut into the inner cover rubber layer 13 from the outer peripheral surface of the tubular body.

  In this way, the tubular body having the cuts formed on the outer peripheral surface is rotated in the same manner as the cuts, and is turned into a circular shape with a predetermined width. The transmission flat belt 10 in the form of an endless belt can be completed.

In this embodiment, the transmission flat belt 10 whose outer peripheral surface (back surface) is a rubber-coated canvas layer will be described as an example. However, in the present invention, the outer peripheral surface is also formed of a cover rubber layer in the same manner as the inner surface side. Is also possible.
In such a case, the incision may be provided on either the inner surface side or the rear surface side. However, it is preferable that the side provided with the incision is provided on the side where the deterioration is more likely to occur when used. .

Whether or not this is a side where deterioration is likely to occur can be determined as a side where deterioration is likely to occur, for example, a side where frictional heat is likely to be generated, such as a contact area with a pulley or a more loaded side. For example, once the transmission flat belt is stretched over a pulley and trial run for several hours, the surface temperature of the front and back of the transmission flat belt is measured, and the surface temperature on the side where the cut is provided is higher than the opposite side. If the temperature is high, shift to actual use as it is, and conversely, if the side where the notch is provided is colder, hang the transmission flat belt on the pulley in the opposite direction and actually use it. It may be used for.
In this way, when used over the pulley, the life of the transmission flat belt can be further extended by selecting and using the front and back.

Further, in the present embodiment, the case where a circumferential notch continuous in the circumferential direction is formed is described as an example in terms of easy manufacture and a point that the effect of preventing the occurrence of warpage can be exhibited more remarkably. However, in the present invention, for example, incisions as illustrated in FIGS. 4a) and b) can be employed.
FIGS. 4a) and 4b show a front view from the surface on which the notch of the transmission flat belt 10 is formed. In FIG. 4a), the notch C ′ does not appear in the circumferential direction of the belt. It is extended in a continuous state.
In order to form the cuts C ′ in such a discontinuous state, for example, in the method described above, a plurality of blades arranged at a predetermined interval are continuously applied to the surface of the tubular body that has been circumferentially moved. The discontinuous cut C ′ can be formed by repeating contact and separation instead of contact.

In FIG. 4b), the cut C ″ is inclined in the circumferential direction by a predetermined angle (θ) with respect to the belt circumferential direction.
If the notch C ″ is formed in the transmission flat belt so that the angle (θ) is a predetermined value or more, there is a risk of generating noise and lowering the conduction ability during operation of the transmission flat belt. Therefore, in order to suppress the reduction in transmission capability and the generation of noise, the angle (θ) is cut into the transmission flat belt so that the angle (θ) is usually 45 degrees or less, preferably 30 degrees or less. "Is preferably formed.
In order to form the incision C ″ by providing this inclination, for example, in the method described above, the blade edge of a single blade is made to enter the surface of the tubular body, and the blade is moved while the tubular body is moved around. Is moved at a constant speed in the length direction of the tubular body to form a spiral cut on the outer peripheral surface of the tubular body, and a cut is provided by inclining the transmission flat belt from the tubular body. A transmission flat belt having C can be produced.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

(Manufacture of transmission flat belts)
(Manufacture of preforms)
A rubber-coated canvas is wound around the circumference of a cylindrical molding drum having a circumference of about 1200 mm, an unvulcanized rubber sheet for the intermediate rubber layer 14a is wound, and then the RFL-treated core wire is spirally spun. Further, the unwrapped rubber sheet for the inner cover rubber layer was wrapped and integrated to produce a tubular preform.
The rubber used in the production of the preform was a hydrogenated nitrile rubber zinc methacrylate nanocomposite product (“ZEON SUPER COMPOSITE” manufactured by Nippon Zeon Co., Ltd.) in which polyamide short fibers were dispersed.
The canvas used was a cotton / polyester blended canvas. Further, a core wire having a diameter of 0.7 mm using an aramid fiber was used.

(Incision formation, transmission flat belt cutting)
A plurality of circumferential cuts with a depth of 0.6 mm are provided at 2.5 mm pitch intervals in the length direction of the preform so as to go around the outer peripheral surface of the preform, and the preform with the cuts provided. The transmission flat belt cut out with a width of 20 mm from the above was used as the transmission flat belt of the example.
In addition, this notch was formed in a direction parallel to the belt circumferential direction without providing an inclination (θ = 0 degree).
Further, a transmission flat belt similarly cut out with a width of 20 mm from a portion of the preform that was not provided with a cut was used as the transmission flat belt of the comparative example.
The transmission flat belts of this example and comparative example are formed to have a width of 20 mm, a circumferential length of 1200 mm, and a thickness of 2.5 mm. The transmission flat belt of the example has a circumferential shape that is continuous in the belt circumferential direction. 7 cuts are formed at intervals of 2.5 mm.
The transmission flat belt of the comparative example is not provided with a cut.

(Belt running test)
As shown in FIG. 5, the belt running test was carried out by passing the transmission flat belts of the examples and comparative examples so as to be in contact with the four pulleys.
That is, using the driving pulley P1 with a diameter of 200 mm, the driven pulley P2 with a diameter of 150 mm to which a load of 30 horsepower is connected, and two unloaded pulleys P3 and P4 with a diameter of 75 mm, the transmission flat belt of the embodiment is used. The side where the cut is formed contacts the drive pulley P1 and the driven pulley P2, and the side where the rubber coat canvas layer is formed contacts the two unloaded pulleys P3 and P4, and the driven pulley P2 A belt running test was carried out by rotating the driving pulley P1 at a rotational speed of 2000 rpm while applying a force in the direction of the arrow in the figure to adjust the transmission flat belt to generate a tension of 40 kgf.
In the transmission flat belt of the comparative example, the side corresponding to the notch forming side of the transmission flat belt of the embodiment is in contact with the driving pulley P1 and the driven pulley P2, and the side on which the rubber coat canvas layer is formed is unloaded. The two pulleys P3 and P4 were placed in contact with each other to run in the same manner.
When this belt running test was carried out in an atmosphere of 75 ± 3 ° C., the transmission flat belt of the comparative example was in a state in which a large slip occurred at the time point of 110 hours and the transmission was practically impossible. The transmission flat belt was still operating normally after 400 hours.

  Also from this, a notch extending along the belt circumferential direction of the transmission flat belt is formed on the surface used for friction transmission, and this notch is formed on the cover rubber layer from the surface of the friction transmission surface. It can be seen that the belt life can be extended by being formed in a cut state.

The fragmentary sectional view which shows the flat belt for transmission of one Embodiment. The partial front view which shows the flat belt inner surface for transmission of the embodiment. The fragmentary sectional view which shows the effect | action of the notch | incision at the time of rubber | gum degradation of the flat belt for transmission. The partial front view which shows the flat belt inner surface for transmission of other embodiment. Explanatory drawing explaining the test method of a belt running test.

Explanation of symbols

  10: flat belt for transmission, 13: inner cover rubber layer, C: notch

Claims (3)

It is formed in an endless belt shape so as to be used for frictional transmission over a plurality of pulleys, at least one of the inner surface side and the rear surface side is formed by a cover rubber layer, and the surface is formed flat. Is a transmission flat belt used for the friction transmission,
The flat surface is formed with a cut extending along the belt circumferential direction, and the cut is formed in a state of being cut from the surface of the flat surface with respect to the cover rubber layer. A flat belt for power transmission characterized by being made. The thickness of the cover rubber layer and D _0, the depth of cut formed in the cover rubber layer is taken as D _1, the incision such that _{(D 0> D 1 ≧ D} 0/2) The transmission flat belt according to claim 1, which is formed. A plurality of the cuts are formed in the cover rubber layer at intervals in the belt width direction, and when the depth of the cut formed in the cover rubber layer is D ₁ and the interval is P, P / The transmission flat belt according to claim 2, wherein a plurality of cuts are formed in the cover rubber layer at intervals such that D ₁ = 2.5 to 25.

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