JPH1089418A - Toothed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of the toothed belt so as to increase the running life of a toothed belt, by enhancing the strength of the toothed area of the toothed belt. SOLUTION: At one side of tooth rubber layer 12 of a toothed belt 10 a tooth area 14 and a tooth bottom area are formed alternately, and at its contour sail cloth 20 is provide. At the other side of the tooth robber layer 12 a back rubber layer 16 is applied in an integrated way, and multiple core wire elements 18 are inserted at boundary face between the tooth rubber layer 12 and back the rubber layer 16. Over the entire tooth rubber layer 12 a lot of short fibers 2 are mixed, and the short fibers 22 are aligned in a width or length direction of the toothed belt 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt used as a timing belt or a synchronous belt, and more particularly to a motor of a vehicle such as an automobile which rotates from a crankshaft to a camshaft, a balancer shaft, a drive shaft of a fuel injection pump, and the like. The present invention relates to a toothed belt used as a power transmission belt for transmitting a driving force.

[0002]

2. Description of the Related Art Conventionally, a toothed belt generally includes a tooth rubber layer, and tooth portions and tooth bottom portions are alternately formed on one surface of the tooth rubber layer. A back rubber layer is integrally applied to the other surface of the tooth rubber layer, and a core wire is embedded at a boundary surface between the tooth rubber layer and the back rubber layer. In recent years, as the performance of motors for vehicles such as automobiles has improved, the number of revolutions of the crankshaft has increased, and a greater load has been placed on the toothed belt used to rotationally drive auxiliary shafts such as camshafts and injection pump shafts. Will hang.

[0003]

With the increase in the load, the toothed portion of the toothed belt in the toothed belt hastened. As a measure to prevent this early tooth chipping, it is conceivable to widen the belt width.However, the belt width of the toothed belt is limited by the mounting conditions of the prime mover of vehicles such as automobiles. Can not be. Therefore, the problem of early loss of the tooth portion as described above cannot be dealt with by increasing the belt width of the toothed belt.

[0004] It is an object of the present invention to provide a toothed belt of the type described above, which is designed to solve the problem of premature tooth loss without increasing the belt width. is there.

[0005]

SUMMARY OF THE INVENTION A toothed belt according to the present invention comprises a toothed rubber layer, which has alternating teeth and roots on one side thereof. A tooth cloth and a tooth bottom of the tooth rubber layer are provided so as to be covered with a canvas, and a back rubber layer is integrally applied to the other surface of the tooth rubber layer. A plurality of core elements are interposed at the boundary surface between the tooth rubber layer and the back rubber layer, and these core elements extend along the length direction of the toothed belt and are arranged along the width direction thereof. . According to the present invention, in such a toothed belt, a large number of short fibers are mixed in the tooth rubber layer over the entirety and are regularly oriented.

[0006] Preferably, the short fibers are oriented in the longitudinal direction of the toothed belt. In this case, the staple fibers are oriented along the contour surface in the region close to the alternate contour surfaces of the tooth portion and the tooth bottom of the tooth rubber layer, and in this case, the short fibers are oriented in the central region of the tooth portion of the tooth rubber layer. It can be oriented substantially perpendicular to the plane of the backing rubber layer. On the other hand, the short fibers may be oriented in the width direction of the toothed belt.

In the present invention, the short fibers are preferably aramid short fibers, and the aramid short fibers may be either meta-aramid short fibers or para-aramid short fibers. The length of the short fibers may be from about 1 to about 6 mm, preferably about 3 mm. Also, about 3 to about 30 parts by weight of short fibers may be mixed with 100 parts by weight of the raw rubber of the tooth rubber layer, but preferably about 6.5 parts by weight of short fibers are mixed.

In the present invention, a hydrogenated nitrile rubber having a hydrogenation rate of 91% or more is used as a raw rubber used for the tooth rubber layer and the back rubber layer, and the raw rubber is a peroxide-based vulcanizing agent. May be added, or a sulfur-based vulcanizing agent and a vulcanization accelerator may be added.

[0009] In the present invention, the canvas is preferably pre-formed, wherein the stretch when the canvas is stretched and broken is about 30 to about 80% of its original length. Further, the canvas can be constituted by a stretchable composite yarn extending along the longitudinal direction of the toothed belt and a non-stretchable yarn extending along the width direction of the toothed belt. Further, the canvas can be treated with a resorcinol-formaldehyde latex solution.

In the present invention, the core elements may be formed from high strength glass fibers, wherein the core elements may be arranged with a gap of about 0.17 to about 0.28 mm. The core elements may also be formed from aramid fibers, where the core elements may be arranged with a gap of about 0.25 to about 0.36. Preferably, the core element is treated with a resorcinol-formaldehyde latex solution, and an overcoat layer of a rubber paste solution is formed on the core element, and a cashew-modified phenol resin layer is preferably formed on the overcoat layer. Can be formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a toothed belt according to the present invention will be described with reference to the accompanying drawings.

Referring first to FIG. 1, a first embodiment of a toothed belt according to the present invention is indicated generally by the reference numeral 10, in which a portion cut from the toothed belt 10 is shown in perspective. This is shown as a diagram. The toothed belt 10 includes a tooth rubber layer 12, and tooth portions 14 and tooth bottom portions 15 are alternately and integrally formed on one surface of the tooth rubber layer 12. Further, the toothed belt 10 includes a back rubber layer 16 integrally applied to the other surface of the tooth rubber layer 12, and a plurality of cores embedded in a boundary surface between the tooth rubber layer 12 and the back rubber layer 16. And a line element 18. Such a large number of cord elements 18 are obtained, for example, by spirally winding a pair of cords along the length direction of the toothed belt 10. In addition,
Preferably, one of the pair of cords is an S-strand cord and the other cord is a Z-strand cord. The toothed belt 10 further includes tooth portions 14 of the tooth rubber layer 12.
And a fabric 20 applied to the face of the root 15, which is preferably formed as a woven fabric of aramid fibers and nylon fibers, as will be explained in more detail below.

As shown in FIG. 1, a large number of short fibers 22 are mixed almost uniformly throughout the tooth rubber layer 12, and the short fibers 22 are regularly distributed in the tooth rubber layer 12. That is, in the embodiment shown in FIG. 1, the short fibers 22 are oriented along the length direction of the toothed belt 10 in a region close to the surfaces of the tooth portions 14 and the tooth bottom portions 15 of the tooth rubber layer 12, In the central region of each tooth portion 14, short fibers 2
2 is oriented so as to be perpendicular to the surface of the backing rubber layer 16. In any case, in the first embodiment shown in FIG. 1, the short fibers 22 are oriented in a direction perpendicular to the generatrix forming the contour surfaces of the tooth portions 14 and the tooth bottom portions 15 of the tooth rubber layer 12.

FIG. 2 is an enlarged cross-sectional view of the tooth bottom 15 shown in FIG. As shown in FIG.
5, the core element 18 is shown in contact with the canvas 20, but in practice, the core element 18 and the canvas 2
Between 0 and 0, there is a thin rubber layer that becomes a part of the tooth rubber layer 12. As described above, the core element 18 is the tooth rubber layer 1.
2 and the back rubber layer 16, a part of each core element 18 is embedded in the tooth rubber layer side including the short fiber 22, and the other part of each core element 18 Is embedded in the back rubber layer 16 side. In the present embodiment, the embedding depth J of each core element 18 with respect to the tooth rubber layer 12 is set to approximately one third of the diameter d, and the embedding depth L of each core element 18 with respect to the back rubber layer 16 side. Is approximately two-thirds of its diameter d. In short, a part of the tooth rubber layer 12, that is, the rubber mixed with the short fibers, partially enters the gap between the adjacent core elements 18.

As shown in FIG. 2, the plurality of core elements 18 are arranged so as to have a predetermined gap g therebetween.
Can be appropriately changed according to the material of the core element 18. For example, when the core element 18 is formed from high-strength glass fiber, the gap g between the plurality of core elements 18 is about 0.
The gap g between the plurality of core elements 18 is in the range of about 0.25 to about 0.36 mm when the core elements 18 are formed from aramid fibers. .

Referring to FIG. 3, there is shown a second embodiment of a toothed belt according to the present invention, in which components corresponding to those of the toothed belt shown in FIG. 1 have the same reference numerals. It is shown using. In the second embodiment, the second embodiment is substantially the same as the first embodiment except that the short fibers 22 in the tooth rubber layer 12 are oriented in a different direction from the first embodiment. Are the same. In short, in the second embodiment, the short fibers 22 are oriented along the width direction of the toothed belt 10, so that the short fibers 22 are oriented along the tooth portions 14 and the tooth bottom portions 15 of the tooth rubber layer 12. Are parallel to the generating line that forms the contour surface of.

Here, for convenience of explanation, in the following description,
The orientation of the short fibers 22 in the tooth rubber layer 12 is
In the case where the orientation of the short fibers 22 in the tooth rubber layer 12 is along the width direction of the toothed belt 10 (the first embodiment), The second embodiment) will be referred to as the belt width direction orientation.

In either case of the first and second embodiments, the short fibers 22 are preferably made of aramid fibers, and the aramid short fibers may be either meta-aramid fibers or para-aramid fibers. Regarding the mixing amount of the short fibers 22 in the tooth rubber layer 12, 100 parts of raw rubber (phr:
parts per hundred parts rubber) and about 3 to about 30 parts (phr), preferably about 6.3 parts (phr)
And the ratio of As the raw material rubber, a hydrogenated nitrile rubber is preferably used, and the vulcanization of the hydrogenated nitrile rubber is not particularly limited, but vulcanization with an organic peroxide or vulcanization with sulfur or the like is preferable.

It is generally known that when short fibers are mixed in a hydrogenated nitrile rubber and vulcanized, its elasticity is lost and its hardness is increased. On the other hand, it is known that when carbon black is added to hydrogenated nitrile rubber and vulcanized, its elasticity is rich. Therefore, the tooth rubber layer 1
In order to obtain a desired elasticity or hardness when a predetermined amount of the short fiber 22 is mixed with the mixture 2, the amount of carbon black added may be adjusted. Since the internal heat generated during running of the toothed belt 10 is deeply related to the elastic modulus of the tooth rubber layer 12, carbon black is
Can also function as a regulator to suppress internal heat generation during traveling.

In the first and second embodiments, the canvas 20 is made from a woven cloth twilled with composite yarns along the length of the toothed belt 10 and non-stretchable yarns along the width of the toothed belt 10. It is formed, but may also be formed by other woven fabrics, such as those obtained from satin weave, plain weave or various modified weaves.

The composite yarn of the canvas 20 can be composed of, for example, a core yarn, a spun yarn wrapped around the core yarn, and a crimped yarn wrapped around the core yarn in a direction opposite to that of the spun yarn. . The core yarn is preferably a polyurethane elastic yarn, the spun yarn is a heat-resistant aramid fiber, and the crimped yarn is an abrasion-resistant aliphatic synthetic fiber nylon fiber. Can be used. On the other hand, the non-stretchable yarn of the canvas 20 preferably has excellent rigidity and heat resistance. For example, a filament yarn of nylon fiber is suitable.

As described above, in the canvas 20, the toothed belt 1
A composite yarn having elasticity along the length direction of 0 is used,
On the other hand, non-stretchable yarn is used along the width direction of the toothed belt 10. Accordingly, the canvas 20 is provided with elasticity along the length direction of the toothed belt 10.

Next, a method for manufacturing the toothed belt 10 will be described with reference to FIGS.

First, as shown in FIG. 4, a preformed toothed drum 24 is prepared, and a tooth portion 26 is provided around the drum. The preformed toothed drum 24 has a toothed roller 2
The toothed roller 28 is provided with teeth 30 which cooperate with the teeth 26 of the preformed toothed drum 24. The preformed toothed drum 24 and toothed roller 28 are rotated in the directions shown by arrows A and B, respectively.

The canvas material 20 'is supplied to the preformed drum 24 so as to surround a part of the periphery of the preformed drum 24, and is introduced into an area of engagement with the toothed roller 28, at which time the canvas material 20' is The two teeth 26 and 30 cooperate to preform in a corrugated manner. The canvas material 20 ′ has the same woven fabric structure as the above-described canvas 20, and eventually becomes the canvas 20 of the toothed belt 10. The supply of the fabric material 20 ′ to the preformed toothed drum 24 is performed such that the stretchable composite yarn is perpendicular to the rotation axis of the preformed toothed drum 24.

As shown in FIG. 5, the preformed toothed drum 2
A steel belt 32 is applied to a part of the periphery of the drum 4 with an appropriate pressing force, and the steel belt 32 is caused to run at the same speed as the peripheral speed of the preformed toothed drum 24. A compound rubber sheet 12 'is supplied between the preformed toothed drum 24 and the steel belt 32, thereby integrating the preformed canvas material 20' and the compound rubber sheet 12 '. That is, compounded rubber sheet 1
2 'is pressed by the steel belt 32 and is preformed according to the shape of the preformed canvas material 20'. In short, an intermediate product is obtained in which the preformed canvas material 20 'and the compounded rubber sheet 12' preformed according to the preforming are integrated.

Teeth 14 'and roots 15' are alternately formed on the preformed compounded rubber sheet 12 ', and the teeth 14' and the roots 15 'are formed on the teeth 14 of the belt 10 having finished teeth. And a tooth rubber layer 12 comprising a tooth bottom 15. A large number of short fibers are entirely mixed and distributed in the compound rubber sheet 12 'before preforming, and the entire short fibers are substantially oriented in one direction.

The compound rubber sheet 12 'is formed on the preformed toothed drum 24 in such a manner that the short fibers in the compounded rubber sheet 12' make an angle of substantially 90 degrees with the rotation axis of the preformed toothed drum 24. Is introduced, the intermediate product is a toothed belt 10 as shown in FIGS. 1 and 2, that is, a toothed belt 10 in which the short fibers 22 are oriented in the belt length direction (first embodiment). Used in the manufacture of

On the other hand, the compound rubber sheet 12 'is formed on the preformed toothed drum 24 in such a manner that the short fibers in the compounded rubber sheet 12' are substantially parallel to the rotation axis of the preformed toothed drum 24. When introduced, the intermediate product is a toothed belt 10 as shown in FIG. 3, that is, a toothed belt 10 in which the short fibers 22 are oriented in the belt width direction (second belt 10).
Of the present invention).

After the above-mentioned intermediate product is sequentially cut to a predetermined length, the cut intermediate product is wound around a toothed belt forming drum 34 as shown in FIG. 6, and the cut edges are brought into contact with each other. Can be Toothed belt forming drum 34 is formed with teeth 36 and tooth bottoms 38 alternately,
The profile of the teeth 36 matches the profile of the root 15 of the finished toothed belt 10, and the profile of the root 38 matches the profile of the teeth 14 of the finished toothed belt 10.

Subsequently, a pair of cords 18 'are spirally wound around the cut intermediate product wound on the toothed belt forming drum 34 as shown in FIG. 'Is an S-strand core, and the other is a Z-strand core. The pair of cords 18 'are arranged so as to have a predetermined gap, and the gap can be appropriately changed according to the material of the cord 18'. For example, when the cord 18 'is formed from high-strength glass fiber, the cord 18' is wound with a gap of about 0.17 to about 0.28 mm, and the cord 18 'is aramid fiber. From about 0.25 to about 0.36 mm.
It is wound so as to leave a gap in the range. The pair of cords 18 ′ eventually become a plurality of cord elements 18 in the finished toothed belt 10.

After winding the pair of cords 18 ', a compound rubber sheet 16' is further wound on the cords, and the compound rubber sheet 16 'is finally turned on the back of the belt 10 with finished teeth. It becomes the rubber layer 16.

Thereafter, the belt components 12 ', 16',
The toothed belt forming drum 34 having 18 'and 20' is placed in a vulcanization oven (not shown) where it undergoes a vulcanization process at a predetermined temperature and pressure. As shown in FIG.
There are numerous gaps between the belt components 12 ', 16', 18 'and 20', which are eliminated during the vulcanization process.

After the vulcanization, as shown in FIG. 7, a toothed belt slab 10 'having a cylindrical shape is vulcanized around the toothed belt forming drum. Thereafter, the toothed belt forming drum 34 is taken out of the vulcanizing oven,
The toothed belt slab 10 'is extracted therefrom. After the toothed belt slab 10 'is polished by a grinder or the like, the toothed belt 10 having a desired belt width can be obtained by cutting the belt slab 10' into an appropriate width. In FIG. 7, each component of the toothed belt slab 10 ′ is assigned the same reference number as each component of the finished toothed belt 10.

As is apparent from the above description, in the finished toothed belt 10, the elastic composite yarn of the canvas 20 extends along the length direction of the toothed belt 10, and The sex thread extends along the width direction of the toothed belt 10. In other words, FIGS.
According to the method of manufacturing the toothed belt 10 shown in FIG. 1, the canvas material 20 ′ is provided with elasticity only along the circumferential direction of the preformed toothed drum 24 so that the finished toothed belt 10
Is preformed into a shape following the tooth profile of
It is not necessary to give 0 'more elasticity than necessary. For example,
The canvas material 20 'is provided with low stretch so that the stretch when the canvas is stretched and broken is 30 to 80% of the original length. Heretofore, since the canvas material is wound around the toothed belt forming drum 34 without being preformed, the canvas material is required to have great elasticity.

The evaluation of the finished toothed belt 10 is evaluated as the formability MB, which means that the contours of the adjacent teeth 14 and the bottom 15 of the finished toothed belt 10 are adjacent to each other of the toothed belt forming drum 34. The determination is made based on whether or not the contour shapes of the tooth bottom portion 38 and the tooth portion 36 match within a predetermined allowable range. To elaborate, first,
As shown in FIG. 8, the distance BP per pitch is measured along the contours of the alternately provided teeth 36 and roots 38 of the toothed belt forming drum 34, and then FIG.
As shown in FIG. 7, the distance TP per pitch is measured along the contours of the tooth portions 14 and the tooth bottom portions 15 provided alternately on the finished toothed belt 10. Formability MB is defined as the percentage of distance TP to distance BP as shown by the following equation. MB = TP / BP × 100

If the formability MB is 93% or more, the finished toothed belt 10 is evaluated as good, and if the formability MB is less than 93%, the finished toothed belt 10 is regarded as poor. Be evaluated.

As shown in Table 1 below, five types of compounded rubber materials A to E to be used in the production of the toothed belt are shown.
Was prepared.

[Table 1]

In Table 1, * 1 to * 9 represent the following items. * 1: Hydrogenation rate is percentage (%) * 2: Iodine value is anonymous * 3: Type of compounding material and parts by weight of compounding material with respect to 100 parts by weight of rubber raw material (unit: phr) * 4: 4, 4 ' -(Α, α-dimethylbenzyl) diphenylamine (this is NAUGAR from Uniroyal Chemical)
* 5: Abbreviation of N-isopropyl-N'-phenyl-p-phenylenediamine * 6: Peroxide system composed of dicumyl peroxide and 1,3-bis (t-butylperoxy-isopropyl) benzene Vulcanizing agent (the former is a die cup 4 from Hercules)
0C, the latter being available as Peroximon F40 from Nippon Oil & Fats Co., Ltd.) * 7: Abbreviation of trimethylolpropane / trimethacrylate * 8: Tetramethyltyrium disulfide and dipentamethylenetyrium tetra Sulfur-based vulcanization accelerator consisting of sulfide and N-cyclohexyl-2-benzothiazyl sulfenamide * 9: Abbreviation of tellurium diethyldithiocarbamate In the table, "***" indicates that the compound is not blended.

As is clear from Table 1, compounded rubber material A
Is 100% of hydrogenated nitrile rubber with a hydrogenation rate of 96%, iodine value of 11 and Mooney viscosity of 120 or more as rubber raw material.
20 parts by weight of carbon black, 10 parts by weight of trimellitate isonolyl, 1.0 part by weight of stearic acid, 1.5 parts by weight of NAUGARD 445, 25 parts by weight
Parts by weight zinc methacrylate, 10 parts by weight zinc white, 18 parts by weight
It is obtained by adding parts by weight of a peroxide-based vulcanizing agent (die cup 40C + peroximon F40) and 6 parts by weight of TMP. A compound rubber sheet (A) was obtained from the compound rubber material A by extrusion molding. Next, a sample piece for a low elongation range modulus test and a sample piece for a compressive stress test were prepared from the compounded rubber sheet (A), and then the sample pieces were vulcanized.

The compounded rubber material B is obtained by further mixing 6.5 parts by weight of a meta-aramid short fiber having a fiber length of 3 mm into the compounded rubber material A. The compounded rubber sheet (B) was also obtained from the compounded rubber material B by extrusion molding. At this time, the short fibers mixed in the compounded rubber material B were oriented in the extrusion direction. Next, a sample piece for a low elongation range modulus test and a sample piece for a compressive stress test were prepared from the compounded rubber sheet (B), and then these sample pieces were vulcanized. In the case of the compounded rubber sheet (B), two types of sample pieces for the low elongation modulus test are prepared, and in one type of sample piece, the short fibers are oriented parallel to the tensile direction. In the other type of specimen, the short fibers are oriented in a direction perpendicular to the tensile direction. Also. Two types of specimens are also prepared for the compression stress test. In one type of specimen, the short fibers are oriented parallel to the compression direction, and in the other type of specimen, the short fibers are compressed. The short fibers are oriented perpendicular to the direction.

The compounded rubber material C is 60 parts by weight of carbon black and 10 parts by weight with respect to 100 parts by weight of a hydrogenated nitrile rubber having a hydrogenation rate of 92.8%, an iodine value of 21 and a Mooney viscosity of about 78 as a rubber raw material. Of trimellitate isonolyl, 1.0 part by weight of stearic acid and 1.0 part by weight of I
It is composed of PPD, 5.0 parts by weight of zinc white, 0.8 parts by weight of sulfur, 2.7 parts by weight of a sulfur-based vulcanization accelerator, and 1.0 part by weight of Te-EDC. A compound rubber sheet (C) was obtained from the compound rubber material C by extrusion molding. In addition, a sample piece for a low elongation range modulus test and a sample piece for a compressive stress test were prepared from the compounded rubber sheet (C), and then these sample pieces were vulcanized.

The compounded rubber material D was prepared by mixing 40 parts by weight of carbon black, 10 parts by weight of trimellitate isonolyl, 1.0 part by weight of stearic acid, and 1.0 part by weight based on the same rubber raw material as compounded rubber material C. Of IPPD, 5.0 parts by weight of zinc white, 0.8 parts by weight of sulfur, 2.7 parts by weight of a sulfur-based vulcanization accelerator, and 1.0 part by weight of Te-EDC,
In addition, only 6.5 parts by weight of meta-aramid short fibers having a fiber length of 3 mm are mixed. The compounded rubber sheet (D) was also obtained from the compounded rubber material D by extrusion molding. At this time, the short fibers mixed in the compounded rubber material D were oriented in the extrusion direction. After preparing a test piece for a low elongation range modulus test and a test piece for a compressive stress test from the compounded rubber sheet (D), the test pieces were vulcanized. In the case of the compound rubber sheet (D), two types of specimens are prepared for the low elongation modulus test specimen and the compressive stress test specimen, respectively, as in the case of the compound rubber sheet (B). Was.

The compounded rubber material E is a compounded rubber material A further mixed with para-aramid short fibers having a fiber length of 3 mm by 6.5 parts by weight. The compounded rubber sheet (E) was also obtained from the compounded rubber material E by extrusion molding. At this time, the short fibers mixed in the compounded rubber material E were oriented in the extrusion direction. After preparing a test piece for a low elongation range modulus test and a test piece for a compressive stress test from the compounded rubber sheet (E), these test pieces were vulcanized. In the case of the compounded rubber sheet (E), two types of specimens are prepared for the low elongation modulus test sample and the compressive stress test sample, as in the case of the compounded rubber sheet (B). Was.

Although not shown in Table 1, the compound rubber material A was mixed with a meta-aramid short fiber having a fiber length of 3 mm by 6.5 mm.
A compound rubber material in which only a part by weight is mixed in a non-oriented (random direction) is also prepared, and a compound rubber sheet obtained by extrusion molding from this compound rubber material is hereinafter referred to as (F).

Next, the compounded rubber sheet (A) described above,
Using the respective test pieces obtained from (B), (C), (D) and (E), a low-stretch area modulus test and a compressive stress test were performed. The test results of the low extension region modulus test are shown in the graphs of FIGS. 10 and 11, and the test results of the compressive stress test are shown in FIGS. 12 and 13.

In the low elongation range modulus test, a tensile stress was applied to each specimen at a rate of 200 mm / min.
The elongation between the 40 mm marks was measured.

In the graph of FIG. 10, reference numeral A indicates the tensile properties of the sample obtained from the compounded rubber sheet (A), and reference numeral B indicates the sample obtained from the compounded rubber sheet (B). Shows the tensile properties of a sample in which the orientation of the short fiber is parallel to the tensile direction, and reference numeral B 'denotes a sample obtained from the compounded rubber sheet (B), The drawing shows the tensile properties of a sample piece whose orientation is perpendicular to the tensile direction. Reference symbol E is a sample piece obtained from the compounded rubber sheet (E), and the orientation of the short fiber is in the tensile direction. The reference symbol E 'denotes a sample piece obtained from the compounded rubber sheet (E), and the orientation of the short fibers is perpendicular to the tensile direction. 4 shows the tensile properties of the test piece.

In the graph of FIG. 11, reference numeral C indicates the tensile properties of the sample obtained from the compounded rubber sheet (C), and reference numeral D indicates the sample obtained from the compounded rubber sheet (D). There, showing the tensile properties of a sample piece whose short fiber orientation is parallel to the tensile direction,
Reference numeral D 'indicates the tensile properties of a sample piece obtained from the compounded rubber sheet (D), in which the short fiber orientation is perpendicular to the tensile direction.

As is clear from the graphs of FIGS. 10 and 11, compared to the sample pieces obtained from the compounded rubber materials A and C, that is, the sample pieces containing no short fiber, B and D of the compounded rubber material were compared.
It can be seen that the sample pieces obtained from Samples E and E, that is, the sample pieces containing short fibers, exhibited a high modulus value, and the elongation percentages of these sample pieces were small. In particular, it can be seen that the sample pieces (B, D and E) containing the short fibers oriented parallel to the tensile direction show a very large modulus value.

In the compression stress test, each specimen was 25.4
Each sample piece was compressed by applying a pressing force between both end surfaces thereof, and the length at the time of compression was measured.

In the graph of FIG. 12, reference symbol A indicates the compression characteristics of a sample obtained from the compounded rubber sheet (A), and reference numeral B indicates a sample obtained from the compounded rubber sheet (B). Shows the compression characteristics of a specimen in which the orientation of the short fibers is parallel to the compression direction, and is indicated by reference numeral B '.
Is a sample piece obtained from the compounded rubber sheet (B),
Shows the compression characteristics of a sample piece in which the orientation of the short fiber is perpendicular to the compression direction. Reference symbol E is a sample piece obtained from the compounded rubber sheet (E), and the orientation of the short fiber is Shows the compression characteristics of a sample piece parallel to the compression direction, and reference numeral E ′ denotes a sample piece obtained from the compounded rubber sheet (E), in which the orientation of the short fiber is in the compression direction. 4 shows the compression characteristics of a right angled specimen.

In the graph of FIG. 13, reference numeral C indicates the compression characteristics of the sample obtained from the compounded rubber sheet (C), and reference numeral D indicates the sample obtained from the compounded rubber sheet (D). The compression property of a sample piece in which the orientation of the short fiber is parallel to the compression direction is shown. Reference symbol D ′ is a sample piece obtained from the compounded rubber sheet (D), 4 shows the compression characteristics of a specimen in which the fiber orientation is perpendicular to the tensile direction.

As is clear from the graphs of FIGS. 12 and 13, the B and D of the compounded rubber material were compared with the sample pieces obtained from the compounded rubber materials A and C, that is, the sample pieces containing no short fibers.
It can be seen that the sample pieces obtained from Samples E and E, that is, the sample pieces containing short fibers, exhibited high compressive stress values, and the compressibility of these sample pieces was small.

The above five types of compounded rubber sheets (A),
By using (B), (C), (D) and (E), five types of toothed belts are manufactured as embodiments of the toothed belt according to the present invention, and each of these five types of toothed belts is Reference is made below to example belts 1, 2, 3, 4 and 5. Also, by using the above three types of compounded rubber sheets (A), (C) and (F),
Four types of toothed belts are manufactured as comparative examples of the toothed belt according to the present invention, and these four types of toothed belts are referred to below as Comparative Example belts 1, 2, 3, and 4, respectively.

The construction of the belts 1 to 5 and the belts 1 to 4 of the comparative examples are as shown in Table 2 below.

[0057]

[Table 2]

Example belt 1: As is clear from Table 2, in Example belt 1, the compound rubber sheet (A) was used as the back rubber layer (16), and the compound rubber sheet (A) was used as the tooth rubber layer (12). B) was used. Tooth rubber layer (12)
The orientation of the meta-aramid short fibers was determined to be the belt length direction orientation.

In the belt 1 of the embodiment, the canvas (20)
The woven fabric having the above-mentioned woven fabric structure was used. Specifically, the canvas (20) is a 2/2 twill woven fabric, its elastic composite yarn is a warp yarn, and its density is
150 lines / 25mm. A urethane elastic yarn (420 d) is used as a core yarn for each composite yarn, and an aramid fiber spun yarn (200 d) is wound around the core yarn. 100 d) is wound in the opposite direction to the aramid fiber spun yarn. On the other hand, canvas (2
The density of the non-stretchable weft of 0) is 170 yarns / 25 mm. As the non-stretchable weft, nylon 66 wooly yarn (100 d) is used.

The canvas (20) is pre-treated with a resorcinol-formaldehyde latex (RFL) solution,
Thereby, the adhesiveness to the tooth rubber layer 12 is enhanced.
The RFL solution is formed by adding a carboxylated nitrile rubber as a latex component to an ammonia solution of a chlorophenol formaldehyde condensate, for example, a 2,6-bis-4-chlorophenol derivative.

As the core cord 18 ', a pair of S-strand core cord and Z-strand core cord was used. High-strength glass fiber was used for each cord. Specifically, first, a high-strength glass fiber having a diameter of 7 microns is immersed in a latex solution in which butadiene-styrene-vinylpyridine and chlorosulfonated polyethylene latex are mixed in a weight ratio of 7: 3, that is, an RFL solution, and then dried. To form an RFL layer for each high strength glass fiber. Next, three strands each of which condensed 200 high-strength glass fibers were collected and twisted to make a strand, and further 11 elbows were gathered and twisted in the opposite direction to the twist. Use a cord. The core cord is dipped in a rubber glue solution and then dried to form an overcoat layer. After the formation of the overcoat layer, it is further immersed in a 25% solution of cashew-modified phenol resin in methyl ethyl ketone and then dried to form a cashew-modified phenol resin layer as the outermost layer (see Table 2).

The pair of cords (S twisted and Z twisted) obtained in this manner are used in a toothed belt forming drum 34.
Intermediate products (20 ′ and 1) wound around (FIG. 6)
2 ') to 0.26mm gap between cords ("g" in Fig. 2)
(See Table 2).

The formability (MB) of the toothed belt obtained as Example Belt 1 was good as shown in Table 2.

Example belt 2: As shown in Table 2, in Example belt 2, the compound rubber sheet (A) was used as the backing rubber layer (16) in the same manner as in Example belt 1, and Compounded rubber sheet (B) as rubber layer (12)
Was used. Example belt 2 is substantially the same as example belt 1 except that the orientation of the meta-aramid short fibers of the tooth rubber layer (12) is the belt width direction orientation.
Similarly to the example belt 1, the example belt 2 also
The formability (MB) of the toothed belt was good as shown in Table 2.

Example belt 3: As shown in Table 2, in Example belt 3, a compound rubber sheet (C) was used as the back rubber layer (16), and a compound rubber sheet (C) was used as the tooth rubber layer (12). D) was used. For the orientation of the meta-aramid short fibers of the tooth rubber layer (12), the belt of Example 1 was used.
As in the case of the above, the belt was oriented in the longitudinal direction. The cord 18 'is also made of high-strength glass fiber as in the case of the belt 1 of the embodiment, but as shown in Table 2, in the belt 3 of the embodiment, the high-strength glass fiber itself is RF.
After being treated with the L solution, a bottom twist and a top twist were added to form a core cord, and only the overcoat layer was formed on the core cord (see Table 2). Other items are the same as those in the case of the example belt 1 as is clear from Table 2. As in the case of the example belt 1, also in the example belt 3, the formability (MB) of the toothed belt was good as shown in Table 2.

Example belt 4: As shown in Table 2, in Example belt 4, as in Example belt 3, compound rubber sheet (C) was used as backing rubber layer (16), and tooth Compounded rubber sheet (D) as rubber layer (12)
Was used. Example belt 4 is substantially the same as example belt 3 except that the meta-aramid short fibers of the tooth rubber layer (12) are oriented in the belt width direction.
As in the case of the example belt 1, also in the example belt 4, the formability (MB) of the toothed belt was good as shown in Table 2.

Example belt 5: As shown in Table 2, in the example belt 5, the compound rubber sheet (A) is used as the back rubber layer (16) as in the case of the example belt 1. A compound rubber sheet (E) was used as the tooth rubber layer (12). In the example belt 4, the para-aramid short fibers of the tooth rubber layer (12) are oriented in the belt length direction. Except for this point, other matters are substantially the same as those of the example belt 1. Also. In Example belt 5, as in Example belt 1, the formability (MB) of the toothed belt was good as shown in Table 2.

Comparative Example Belt 1: In Comparative Example Belt 1, the compounded rubber sheet (A) was used for both the back rubber layer (16) and the tooth rubber layer (12). Other items are substantially the same as those of the example belt 1. Also in the case of the comparative belt 1, as in the case of the example belt 1,
The moldability (MB) of the toothed belt was good as shown in Table 2.

Comparative Example Belt 2: In Comparative Example Belt 2, the compounded rubber sheet (C) was used for both the back rubber layer (16) and the tooth rubber layer (12). Other items are substantially the same as those of the example belt 3 as shown in Table 2. Also in the case of the comparative belt 2, the example belt 1
As in the case of the above, the moldability (MB) of the toothed belt was good as shown in Table 2.

Comparative Example Belt 3: In Comparative Example Belt 3, a compound rubber sheet (A) was used as the back rubber layer (16), and a compound rubber sheet (F) was used as the tooth rubber sheet (12).
Was used. The compounded rubber sheet (F) is obtained from the compounded rubber material obtained by mixing the meta-aramid staple fibers having a fiber length of 3 mm with the compounded rubber material A in an unoriented (random direction) by 6.5 parts by weight as described above. Things. Except for this point, the other points are the same as those of the belt 2 of the embodiment, but the manufacture of the belt 3 of the comparative example is based on the canvas material (2
0 ′) was preformed in the manner shown in FIG.
The compound rubber sheet (F) to be the tooth rubber layer (12) was not preformed, but was applied only to the preformed canvas (20 ') wound around the toothed belt forming drum.

As shown in Table 2, the moldability (MB) of Comparative Example Belt 3 was less than 93%, which was poor. The reason is that, first, the compound rubber sheet (F) to be the tooth rubber layer (12) was not preformed, and the gap between the core elements (18) was Another example is that the gap is set to 0.26 mm, which is smaller than the gap between the elements. In order to obtain good moldability (MB> 93%) without preforming a compound rubber sheet to be a tooth rubber layer, the gap between the core elements must be 0.3 mm or more. .
Further, as another reason, since the orientation of the short fibers contained in the compound rubber sheet (F) to be the tooth rubber layer (12) is random, the flowability of the compound rubber sheet during vulcanization is reduced. It is also inferior.

In short, if the number of core elements is increased by narrowing the gap between the core elements in order to give the toothed belt a large strength, the formability (MB) of the toothed belt deteriorates. However, by preforming a compound rubber sheet to be a tooth rubber layer, good moldability (MB) can be obtained even if the gap between the core elements is 0.3 mm or less.

Comparative Example Belt 4: As is apparent from Table 2, Comparative Example Belt 4 is substantially the same as Comparative Example Belt 3 except that the gap between the core elements is 0.47 mm. . In Comparative Example belt 4, the gap between the core elements was 0.3 mm.
As described above, the formability of the toothed belt (MB)
Is good.

Example belt 1 obtained as described above
5 and Comparative Example belts 1, 2 and 4 were subjected to a running test. In addition, the comparative example belt 3 had poor moldability as described above, so that the comparative example belt 3 could not even be subjected to a running test.

Referring to FIG. 14, there is shown a schematic configuration of a first traveling test apparatus, which comprises four toothed wheels 51, 52, 53 and 54, and toothed wheels 51 and 52. Idler pulley 55 provided between
And a tensioner 56 provided between the toothed wheels 53 and 54. The toothed belt 59 to be tested is shown in FIG.
The four toothed wheels 51, 52, in the manner shown in
53 and 54, idler pulley 55, tensioner 5
It is bridged with 6.

In the first running test apparatus shown in FIG. 14, a plurality of toothed belts run under the same conditions for each of the example belt 1, the example belt 2, the example belt 5, and the comparative example belt 1. The running time was measured for each toothed belt from the start of running to the lack of teeth for evaluation of the running test.

The running test results of the example belt 1, the example belt 2, the example belt 5, and the comparative example belt 1 are shown in Table 2 and the graph of FIG. The running time of each toothed belt is an average value. As is clear from Table 2 and the graph of FIG. 16, the running time of the example belt 1 was 404 hours, the running time of the example belt 2 was 400 hours, and the running time of the example belt 5 was 420 hours. there were. On the other hand, the running time of the comparative example belt 1 is only 126 hours.

Referring to FIG. 15, there is shown a schematic configuration of a second traveling test apparatus, which comprises three toothed wheels 61, 62 and 65, and a toothed wheel 65 and 61. And a tensioner 66 provided. The toothed belt 69 to be tested is wound around the three toothed wheels 61, 62 and 65 and the tensioner 66 in a manner as shown in FIG.

In the second running test apparatus shown in FIG. 15, the belts of Example belt 1, Example belt 3, Example belt 4, Example belt 5, Comparative example belt 1, Comparative example belt 2 and Comparative example belt 4 were used. In each case, a plurality of toothed belts were subjected to a running test under the same conditions, and for the evaluation of the running test, the running time from the start of running to the lack of teeth was measured for each toothed belt. .

The running test results of the example belt 1, the example belt 3, the example belt 4, the example belt 5, the comparative example belt 1, the comparative example belt 2 and the comparative example belt 4 are shown in Table 2 and the graph of FIG. Is shown in The running time of each toothed belt is an average value. As is clear from Table 2 and the graph of FIG. 17, the running time of the example belt 1 is 321 hours, and the running time of the example belt 3 is
The running time of the example belt 4 was 186 hours, and the running time of the example belt 5 was 350 hours. On the other hand, the running time of each of the comparative example belts 1, 2 and 4 is only 125 hours, 30 hours and 146 hours.

As is clear from the above running test results,
It can be seen that the durability of the toothed belt according to the present invention is significantly improved.

In the above-described embodiment, the toothed belt has tooth portions on only one side, but it is understood that the present invention can be applied to a double tooth belt having tooth portions on both surfaces. Should.

[0083]

As is apparent from the above description, in the toothed belt according to the present invention, the teeth are less likely to be chipped, and the running life can be greatly extended.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a first embodiment of a toothed belt according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing an enlarged cross-sectional view of a tooth bottom portion of the toothed belt shown in FIG.

FIG. 3 is a partial side view showing a second embodiment of the toothed belt according to the present invention.

FIG. 4 is a schematic process diagram showing a preforming process of a canvas material in a manufacturing process of the toothed belt according to the present invention.

FIG. 5 is a schematic process diagram showing a preforming process of a tooth rubber sheet in a manufacturing process of the toothed belt according to the present invention.

FIG. 6 is a schematic process diagram showing a winding process of a core cord and a winding process of a back rubber sheet in a manufacturing process of the toothed belt according to the present invention.

FIG. 7 is a schematic process diagram showing a vulcanizing process in the manufacturing process of the toothed belt according to the present invention.

FIG. 8 is a partial side view of a toothed belt forming drum, wherein the distance between one tooth portion and the tooth bottom of the toothed belt forming drum is one pitch for the evaluation of the formability of the toothed belt; FIG. 6 is a diagram showing an aspect of measuring along the line.

FIG. 9 is a partial side view of the toothed belt, which measures the distance of one pitch of an alternate tooth portion and tooth bottom portion of the toothed belt along the contour for evaluating the formability of the toothed belt. FIG.

FIG. 10 is a graph showing the results of low elongation region modulus tests performed on five types of specimens obtained from three types of vulcanized rubber sheets used in the toothed belt according to the present invention.

FIG. 11 shows three different specimens obtained from two different types of vulcanized rubber sheets used in the toothed belt according to the invention and which are different from the three shown in the graph of FIG. 6 is a graph showing the results of a low extension range modulus test.

FIG. 12 is a graph showing the results of compressive stress tests performed on five types of specimens obtained from three types of vulcanized rubber sheets used in the toothed belt according to the present invention.

FIG. 13 was carried out on three specimens obtained from two other types of vulcanized rubber sheets used in the toothed belt according to the invention and shown in the graph of FIG. It is a graph which shows the result of a compression stress test.

FIG. 14 is a schematic view of a first running test apparatus for performing a running test of the example belt and the comparative example belt according to the present invention.

FIG. 15 is a schematic view of a second running test apparatus for performing a running test on the example belt and the comparative example belt according to the present invention.

FIG. 16 is a graph showing a running test result of the toothed belt performed by the first running test device shown in FIG. 14;

FIG. 17 is a graph showing a running test result of the toothed belt performed by the second running test device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Toothed belt 12 Tooth rubber layer 14 Tooth part 15 Teeth root 16 Back rubber layer 18 Core element 20 Canvas 22 Short fiber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 21/00 C08L 21/00

Claims (24)

[Claims] 1. A toothed belt comprising a tooth rubber layer, the tooth rubber layer having tooth portions and tooth bottom portions alternately formed on one surface thereof, and further comprising a tooth rubber layer. A canvas provided so as to cover the teeth and the tooth bottom, a back rubber layer integrally applied to the other surface of the tooth rubber layer, and a boundary surface between the tooth rubber layer and the back rubber layer. A plurality of core elements arranged along the length direction of the toothed belt and arranged along the width direction of the toothed belt. A toothed belt, wherein the fibers are mixed throughout and regularly oriented. 2. The toothed belt according to claim 1, wherein the short fibers are oriented in a longitudinal direction of the toothed belt. 3. The toothed belt according to claim 2, wherein the short fibers are oriented along an alternate contour surface of a tooth portion and a tooth bottom portion of the tooth rubber layer in a region close to the alternate contour surface. A toothed belt characterized by the following. 4. The toothed belt according to claim 3, wherein the short fibers are oriented substantially at right angles to the plane of the back rubber layer in the central region of the teeth of the tooth rubber layer. Toothed belt. 5. The toothed belt according to claim 1, wherein the short fibers are oriented in a width direction of the toothed belt. 6. The toothed belt according to claim 1, wherein the short fibers are aramid short fibers. 7. The toothed belt according to claim 6, wherein the aramid short fibers are meta-based aramid short fibers. 8. The toothed belt according to claim 6, wherein the aramid short fibers are para-aramid short fibers. 9. The toothed belt according to claim 1, wherein the short fibers have a length of about 1 to about 6 mm. 10. The toothed belt according to claim 9, wherein the length of the short fibers is preferably about 3 mm. 11. The toothed belt according to any one of claims 1 to 10, wherein about 3 to about 30 parts by weight of short fibers are mixed with 100 parts by weight of the raw rubber of the tooth rubber layer. A toothed belt characterized by being made. 12. The toothed belt according to any one of claims 1 to 10, wherein preferably about 6.5 parts by weight of short fibers is mixed with 100 parts by weight of the raw material rubber of the tooth rubber layer. A toothed belt, characterized in that: 13. The toothed belt according to claim 1, wherein the raw rubber used for the tooth rubber layer and the back rubber layer has a hydrogenation rate of 91% or more. A toothed belt characterized by being rubber. 14. The toothed belt according to claim 1, wherein the tooth rubber layer and the back rubber layer are made of a compounded rubber obtained by adding a peroxide vulcanizing agent to raw rubber. A toothed belt characterized by being obtained. 15. The toothed belt according to any one of claims 1 to 13, wherein the tooth rubber layer and the back rubber layer are obtained by adding a sulfur-based vulcanizing agent and a vulcanization accelerator to raw rubber. A toothed belt obtained from compounded rubber. 16. The toothed belt according to claim 1, wherein said canvas is preformed. 17. The toothed belt according to claim 16, wherein the stretch when the canvas is stretched and broken is about 30 to about 80% of its original length. . 18. The toothed belt according to claim 16, wherein the canvas extends and contracts along a longitudinal direction of the toothed belt, and a stretchable composite yarn extends in a width direction of the toothed belt. And a non-stretchable yarn. 19. The toothed belt according to claim 1, wherein the canvas is treated with a resorcinol-formaldehyde latex solution. 20. The toothed belt according to claim 1, wherein the cord element is formed of high-strength glass fiber. 21. The toothed belt of claim 20, wherein the cord elements are arranged with a gap of about 0.17 to about 0.28 mm. 22. The toothed belt according to claim 1, wherein the cord element is formed of aramid fiber. 23. The toothed belt of claim 22, wherein the cord elements are arranged with a gap of about 0.25 to about 0.36. 24. The toothed belt according to claim 1, wherein the core element is treated with a resorcinol-formaldehyde latex solution, and a rubber glue solution is applied on the core element. A toothed belt having an overcoat layer formed thereon, and preferably a cashew-modified phenol resin layer formed on the overcoat layer.