JPS63235744A - Belt with teeth - Google Patents

Abstract

PURPOSE:To enable the service life and the core fiber size of the title belt to be extended and reduced respectively by using high strength glass fibers for a plurality of cores which are provided between a body portion and a tooth portion in the axial direction and making gaps between cores a predetermined width to strength the bonding power of the body portion and the tooth portion. CONSTITUTION:The body portion 1 of a belt made of rubber is formed in a flat plate shape and a plurality of cores 4 are provided in the longitudinal direction on one face thereof at predetermined gaps transversely. And tooth portions 2 are provided on the side surface of the arrangement side of the cores 4 of the body portion 1 at predetermined gaps in the longitudinal direction. The connection between each tooth portion 2 and the body portion 1 is made through the gaps L between the cores 4. The gap L is set to 25%-40% of the diameter R of the core 4 in order to increase bonding strength of the body portion 1 and the tooth portion 2 of a belt with teeth. And since the density of cores 4 decreases and tensile strength lowers to some extent, high strength glass fibers are used as a material instead of conventional glass fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toothed belt used, for example, for driving an overhanging camshaft of an internal combustion engine of an automobile.
In particular, the present invention relates to a toothed belt that can have a long life and a narrow width.

(Prior technology) Unlike flat belts, V-belts, etc., toothed belts have the advantage of high transmission efficiency because they do not slip, and furthermore, they have the advantage of being extremely low noise compared to transmission devices using gears and chains. have.

For this reason, the scope of use of toothed belts is being expanded, such as being used for synchronously driving overhead camshafts of internal combustion engines in automobiles, for example.

Usually, a toothed belt consists of a main body part 1 made of an elastic material such as rubber, and a toothed belt disposed on one surface of the main body part 1 with a predetermined gap in the longitudinal direction, as shown in Fig. 1. It has a tooth portion 2 extending to . A plurality of core wires 4,4. ... are arranged, and each core wire 4 is 1
It is inserted between the main body part 1 and the tooth part 2. The surface of each toothed portion 2, the surface of the main body portion 1 between adjacent belt toothed portions 2, and the surface of each core wire 4 are covered with toothed portions 3.

Each core wire 4 supports the transmitted load in the belt.

Further, each tooth portion 2 is joined to the main body portion 1 at a gap between adjacent core wires 4. Conventionally, the gap between adjacent core wires 4 is approximately 20% of the diameter of the core wires in the belt width direction. For this reason, the gap between the adjacent core wires 4 was relatively small and the bonding area between them 9 was small, so the bonding force between the main body portion 1 and the tooth portion 2 was relatively weak.

However, if the gap between adjacent core wires 4 is made thicker.

If the arrangement density of the core wires 4 is reduced and the belt width is a certain value,
The number of core wires decreases. The decrease in the number of core wires.

Reduces the tensile strength of the toothed belt itself. In addition, the gap between adjacent core wires becomes larger and the bonding area between the main body part 9 and the toothed part 2 increases, so the bonding force between the two increases. The bonding force is reduced and the rigidity of the tooth portion 2 is reduced.

As a result, the toothed portion 2 may be deformed or damaged, and furthermore, it may cause jumping when meshing with the toothed pulley, resulting in insufficient power transmission.

Furthermore, in conventional toothed belts, E glass fibers have been used as core wires. Since the E glass fiber does not have sufficient tensile strength, if the gap between the core wires 4 is widened in order to improve the bonding strength of the belt teeth 2 to the main body 1, the load applied to one core wire 4 will be increased. There is a risk that it will increase and break. If the bonding area between the main body portion 1 and the tooth portion 2 is increased by widening the gap between the core wires 4, the density of the core wires 4 will decrease, which may reduce the tensile strength of the belt.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to provide a structure in which the main body portion and the tooth portion are firmly joined, and which has excellent tensile strength. Therefore, it is an object of the present invention to provide a toothed belt that can have a long life and be made narrower.

(Means for solving the problem) As a result of experiments, the inventors of the present application used high-strength glass fiber as the core wire instead of the conventional E glass fiber.

Moreover, if the gap between the core wires is set within a predetermined range with respect to the diameter of the core wire in the belt width direction, the tensile strength and the strength of the belt teeth can be significantly improved, and a toothed belt with excellent durability can be obtained. I found out that it can be done.

The present invention has been made based on such knowledge. The present invention provides a flat main body, teeth disposed on one surface of the main body with a predetermined gap in the longitudinal direction, and a widthwise direction between the main body and the teeth. A toothed belt having core wires arranged in parallel with a predetermined gap, the core wires being made of high-strength glass fiber, and the gap between adjacent core wires being in the belt width direction of the core wires. The core wires are arranged so as to be 25 to 40% of the diameter, thereby achieving the above object.

The toothed belt of the present invention will be explained in more detail.

The toothed belt is similar to the conventional toothed belt, as shown in FIG. Teeth 2. Canvas 3. The main body part 1 having the core wires 4 and 4 is in the form of a flat plate made of an elastic material such as rubber, and has a predetermined gap in the width direction on its - face.
Multiple core wires 4, 4. ... are arranged along the longitudinal direction. Further, on the side surface of the main body part 1 on the side where the core wire 4 is arranged, there are 9 toothed parts 2, 2. ... are arranged with a predetermined gap in the longitudinal direction. Therefore, each tooth portion 2 is joined to the main body portion 1 through the gap between each core wire 4. The surface of the tooth portion 2, the surface of the main body portion 1 between adjacent tooth portions 2, and the surface of each core wire 4 are covered with canvas 3.

The gap between adjacent core wires 4 is set to 25 to 40% of the belt width direction diameter R of each core vA4.

By providing such a gap, the main body portion 1 and the belt tooth portion 2 are firmly joined in this gap.

Furthermore, there is no risk that the rigidity of the tooth portion 2 will decrease. If this gap is smaller than 25% of the diameter of the core wires in the belt width direction, the density of the core wires 4 increases and the bonding force between the main body portion 1 and the toothed portion 2 is weak, and the toothed portion 2 Shear failure occurs. On the other hand, if the gap between the core wires 4 is larger than 40% of the diameter of the core wires in the belt width direction, the core wires 4 and the main body 1 made of rubber, etc.
As the bonding force with the tooth portion 2 decreases, the rigidity of the tooth decreases, and there is a risk that the tooth portion 2 may undergo deformation and shear failure.

In conventional toothed belts, the spacing between core wires is .

In contrast, in the toothed belt of the present invention, the gap between the core wires is approximately 25% to 40% of the diameter of the core wire in the belt width direction.

It becomes slightly larger. As a result, the density of the core wire decreases.

The tensile strength of the belt itself will decrease slightly. For this reason, in the toothed belt of the present invention, high-strength glass fiber is used as the core wire in place of the conventionally used E glass fiber.

The high-strength glass fiber has a higher Sin content than the E glass fiber conventionally used for the core wire of toothed belts.

^1203 component, )'The content ratio of Igo component is increasing.

On the other hand, CaO component, B, 0. The content ratio of the ingredients is decreasing. As such a high strength glass fiber.

Examples include S glass fiber, R glass fiber, and T glass fiber.

Table 1 shows the proportions of the components contained in the high-strength glass used for the core wire of the toothed belt of the present invention and the E glass used for the core wire of the conventional toothed belt. Table 2 also shows the physical properties of the high-strength glass fiber and E glass fiber.

(Leaves below) Table 1 Table 2 As described above, by using high-strength glass fiber as the core wire 4, the tensile strength and tensile strength of the core wire 4 itself are improved, so the density of the core wire is increased. It is possible to prevent the tensile strength of the toothed belt from decreasing due to the decrease in the tensile strength of the toothed belt, and together with the improvement of the shear life of the belt teeth, the durability of the toothed belt is significantly improved. Furthermore, in order to improve the tensile strength of the belt, it is also possible to make the belt narrower.

(Example) The present invention will be described below with reference to Examples.

A cylindrical mold with 127 belt tooth grooves in the circumferential direction per run,
Endless nylon teeth were tightly wound around the outer peripheral surface of the mold. After that, while rotating the cylindrical mold on a winding device, high-strength glass fibers with a diameter of 0.
．． 95-j, oOn S glass fibers are used, and the gaps between adjacent core wires are as follows.

The nine turns were wound while continuously shifting the position so that the diameter of the core wire was 25% of the diameter in the belt width direction. Furthermore, a sheet made of hydrogenated nitrile rubber (H3N) was wrapped around the core wire and vulcanized under pressure to produce a main body and belt teeth made of H5N. After completion of vulcanization, the belt was cut into pieces having a widthwise dimension of 15 fl to obtain two toothed belts of the present invention. Similarly, the cord gap is 32% of the diameter of the cord in the belt width direction.
A toothed belt with a width of 150 and a toothed belt with a width of 15 and a width of 40% were obtained.

The obtained toothed belt was wound around a testing machine shown in FIG. 2, and the shear life of the belt teeth was measured. The test machine drives a double overhead camshaft in a four-stroke automobile engine with a displacement of 21, and has two cylinders with Rad pulleys 11 and 11,
and the drive pulley 12.

It has a tension pulley 13. Tooth grooves are formed on the two peripheral surfaces of the Rad pulleys 11 and 11 and the drive pulley 12 to the cylinder, and the toothed belt of the present invention obtained as described above is wound around these, and a flat pulley is used. A tensile pulley 13 applies tension to the toothed belt 10. Rad pulleys 11 and 11 to each cylinder
Number, the number of teeth is 40. The drive pulley 12 has 20 teeth. The mounting tension of the toothed belt IO was 5 kg-f, and the toothed bell 10 was driven at a rotational speed of 26 QOr, p, m. Table 3 shows the time for each toothed belt 10 to undergo shear failure (shear life).

In addition, each toothed belt is between the toothed parts 2.

It was cut in the width direction so that the thickness was about 2 cranes, and the cut piece was observed with an optical microscope to confirm the gap between the core wires relative to the diameter of the core wire in the belt width direction. The diameter R of the core wire in the belt width direction and the core wire gap were measured using a scale attached to a microscope.

The core wire gap between each core wire is 17 mm of the diameter of the core wire in the belt width direction.
%, 20%, 23%, 44% and 48%, but the same five toothed belts as in Example 1 were obtained.

Each toothed belt was subjected to the same test as in Example 1.

The test results are also listed in Table 3.

Upper grade I E glass fiber is used as the core wire, and the gaps between the core wires are large.

17%, 20%, 23%, 2 of the diameter of the core wire in the belt width direction
Eight toothed belts were obtained by arranging them at 5%, 32%, 40%, 44%, and 48%, respectively. The rest is the same as in Example 1. Each toothed belt was subjected to the same test as in Example 1. The test results are shown in Table 4.

In this way, the toothed belt of the present invention has a significantly improved lifespan until shear failure.

A toothed belt similar to that of Example 1 was obtained except that the belt width was 19.11+1. The toothed belt has a length of 30
It was cut into cm pieces and its tensile strength was measured using an Amsler measuring machine. The measurement results are shown in Table 5.

Five toothed belts were obtained in the same manner as in Comparative Example 1, except that the flame stop belt width was 19.1 m, and the tensile strength was measured in the same manner as in Example 2. The measurement results are also listed in Table 5.

Comparison■↓ Eight toothed belts, which were the same as those in Comparative Example 2, except that the belt width was 19.1 fl, were measured for tensile strength in the same manner as in Example 2. The measurement results are shown in Table 6.

(Margin below) Although the toothed belt of the present invention has a wide core gap.

Exhibits better tensile strength than traditional toothed belts. A toothed belt used for driving an overhead camshaft of an automobile is required to have a tensile strength of at least 1250 kg-f, and the toothed belt of the present invention satisfies this condition.

Three toothed belts were obtained in the same manner as in Example 1, except that the gap between the pointed charcoal main wires was 32% of the diameter of the core wire in the belt width direction, and the belt widths were 15 mm, 13 m, and 11 mm, respectively. Ta. The shear life of the belt teeth was measured in the same manner as in Example 1. Further, in the same manner as in Example 2, the initial tensile strength of the belt was measured. The measurement results are shown in Table 7.

Northern Comparison i Using the same three toothed belt as in Example 3 except for using E glass fiber as the core wire, the shear life of the belt teeth and the initial stage of the belt were measured in the same manner as in Example 3. Tensile strength was measured. The measurement results are also listed in Table 7.

This one toothed belt was the same as in Example 3, except that the center line gap was 20% and the belt width was 15 mm.

In the same test as in Example 3, the belt tooth shear life and the initial tensile strength of the belt were measured. The measurement results are shown in Table 8.

Comparison ■1 A toothed belt similar to Comparative Example 6 except that E glass fiber was used as the core wire was prepared in the same manner as Comparative Example 6, and the shear life of the belt teeth and the initial tensile strength of the belt were measured. was measured. The measurement results are also listed in Table 8.

(Left below) Table 7 Table 8 As the belt width becomes smaller, the belt tooth shear life and the initial tensile strength of the belt decrease. Conventional.

A toothed belt used to drive an overhead camshaft of an automobile engine (as shown in Comparative Example 7).

When the cord gap was 20%, the belt width was 15 mm, and the cord was made of E-shaped fiber), the belt tooth shear life was 129 hrs, and the initial tensile strength of the belt was 982 kg-f (see Table 8). 9 In the toothed belt of the present invention, the shear life of the belt teeth is 142 hrs even if the belt width is 13 mm.
.

The initial tensile strength of the belt is 996 kg-f (all cases where the cord gap is 40% of the diameter of the cord in the belt width direction).

(see Table 7), it is superior to conventional toothed belts.

(Effects of the Invention) As described above, the toothed belt of the present invention has a gap between adjacent core wires within a predetermined range relative to the core wire diameter, and uses high-strength glass fiber as the core wire. Therefore, durability and tensile strength are significantly improved, and a longer life and narrower width are realized.

4. Quantity ゛H Figure 1 is a perspective view of a part of a toothed belt, and Figure 2 is a schematic diagram of a toothed belt testing apparatus.

1...Main body part, 2...Belt tooth part, 3...Yamajaku,
4... Core wire.

that's all

Claims (1)

[Claims] 1. A flat main body, a tooth portion disposed on one surface of the main body with a predetermined gap in the longitudinal direction, and between the main body and the tooth portion , a toothed belt having core wires arranged in parallel with a predetermined gap in the width direction, the core wires being made of high-strength glass fiber, and the gap between adjacent core wires being equal to the distance between the core wires. A toothed belt in which each core wire is arranged to have a diameter of 25 to 40% of the belt width direction diameter.