JP6811201B2 - Toothed belt - Google Patents

Description

The present invention relates to a toothed belt in which a back surface portion and a plurality of tooth portions are integrally molded with a thermoplastic elastomer.

The toothed belt is widely used as a power transmission belt in general industrial machinery, agricultural machinery, and the like, and in recent years, its application to heavy-weight transported objects has been promoted. For application to a heavy-weight transported object, it is effective to increase the load capacity by increasing the size of the entire toothed belt (particularly the height of the tooth portion). However, due to the space of the device, miniaturization is also required, and it is particularly desired to increase the load capacity while suppressing the belt width.

Techniques for increasing the load capacity while suppressing the belt width include a technique for arranging a plurality of core wires in the belt thickness direction (see Patent Documents 1 and 2), a technique for arranging the core wires densely in the belt width direction without gaps, and a core. Techniques for increasing the diameter of the wire are known.

JP-A-2014-142046 JP-A-2016-21734

However, Patent Documents 1 and 2 do not disclose the specific size of the belt strength, the configuration of the tooth portion (pitch, height), etc., which are preferable for application to a heavy transported object.

An object of the present invention is to provide a toothed belt which can increase the load capacity while suppressing the belt width and is preferable for application to a heavy transported object.

According to the present invention, a plurality of core wires extending in the longitudinal direction of the belt and arranged in the width direction of the belt, a back surface portion in which the plurality of core wires are embedded, and the back surface portion facing the belt thickness direction. A toothed belt comprising a belt body including a plurality of tooth portions arranged apart from each other in the longitudinal direction of the belt, and the back surface portion and the plurality of tooth portions integrally formed of a thermoplastic elastomer. The belt strength per 1 mm of the belt width is 1.85 kN or more, the pitch of the plurality of teeth is 20 mm or more, the height of each of the plurality of teeth is 5 mm or more, and the thickness of the back surface is 4 mm. A toothed belt characterized by the above is provided.

According to the present invention, as will be shown later in Examples, it is possible to provide a toothed belt which can increase the load capacity while suppressing the belt width and is preferable for application to a heavy transported object.

In the present invention, each of the plurality of core wires may consist of a steel cord, an aramid fiber, or a cord obtained by twisting carbon fibers.
Further, each of the plurality of core wires may be made of a steel cord, may have a strength of 7 to 8 kN, and may have a diameter of 2.3 to 2.6 mm. In this case, by using a steel cord having the features of low elongation and high strength as the core wire, it is possible to more preferably improve the belt strength per unit width.

The pitch of the plurality of core wires may be 3.0 to 3.7 mm, and the distance between the plurality of core wires may be 0.4 to 1.4 mm. In this case, as will be shown later in Examples, an improvement in belt strength per unit width can be more preferably realized by a suitable combination of core wire pitch and spacing.

The thermoplastic elastomer is selected from the group consisting of a polyurethane-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polystyrene-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, and a vinyl chloride-based thermoplastic elastomer. It may be at least one kind.
The thermoplastic elastomer may be a polyurethane-based thermoplastic elastomer and may have a hardness of 85 to 95 °. In this case, a toothed belt having excellent mechanical properties and durability can be obtained. Further, since the polyurethane-based thermoplastic elastomer is widely used for transmission belts and conveyor belts, it is easy to manufacture toothed belts. The type of polyurethane constituting the polyurethane-based thermoplastic elastomer may be a polyether type polyurethane, a polyester type polyurethane, or a polycarbonate type polyurethane.

According to the present invention, it is possible to provide a toothed belt which can increase the load capacity while suppressing the belt width and is preferable for application to a heavy weight conveyed object.

It is sectional drawing which shows the toothed belt which concerns on one Embodiment of this invention, along the belt width direction (along I-I line of FIG. 2). It is sectional drawing along the belt longitudinal direction (along the line II-II of FIG. 1) which shows the toothed belt which concerns on one Embodiment of this invention. It is the schematic which shows the example which used the toothed belt which concerns on one Embodiment of this invention in the elevating transfer apparatus. It is the schematic for demonstrating the manufacturing method of the toothed belt which concerns on one Embodiment of this invention. It is the schematic which shows the traveling test machine used in the traveling test.

As shown in FIGS. 1 and 2, the toothed belt 10 according to an embodiment of the present invention includes a plurality of core wires 1, a back surface portion 2 in which a plurality of core wires 1 are embedded, and a plurality of tooth portions 3. The belt body 10a including the above is provided.

The core wire 1 of the present embodiment is made of a steel cord (a cord obtained by twisting steel fibers). The plurality of core wires 1 extend in the longitudinal direction of the belt and are arranged in the width direction of the belt.

The plurality of tooth portions 3 face the back surface portion 2 in the belt thickness direction and are arranged apart from each other in the belt longitudinal direction. The back surface portion 2 and the plurality of tooth portions 3 are integrally molded with a thermoplastic elastomer. The thermoplastic elastomer constituting the back surface portion 2 and the plurality of tooth portions 3 is a polyurethane-based thermoplastic elastomer in the present embodiment, and has a hardness of 85 to 95 ° (based on JIS K6253: 2012, measured with an A-type hardness tester. ). The type of polyurethane constituting the polyurethane-based thermoplastic elastomer is a polyether type polyurethane, a polyester type polyurethane, or a polycarbonate type polyurethane.

The toothed belt 10 preferably satisfies the following requirements.
・ Belt width W = 50 to 150 mm
・ Belt total thickness H = 9 to 13 mm
・ Thickness of back surface 2 h2 = 4 to 6 mm
・ Height h3 of each tooth 3 = 5-8 mm
・ Pitch P of tooth 3 = 20 to 30 mm
-Diameter D of each core wire 1 = 2.3 to 2.6 mm
・ Strength of each core line 1 = 7-8kN
・ Pitch Pt of core wire 1 = 3.0 to 3.7 mm
-Interval d of core wire 1 = 0.4 to 1.4 mm (the total value of each interval d is 13 to 36% of the belt width W)
-Belt strength per 1 mm of belt width = 1.85 kN or more and 2.60 kN or less.

The toothed belt 10 is used, for example, in the elevating and lowering transfer device 50 as shown in FIG.

The elevating and lowering transfer device 50 has toothed pulleys 51 and 53 arranged side by side on the upper side and toothed pulleys 52 and 54 arranged side by side on the lower side. A pair of toothed pulleys, which are made by cutting an open-end toothed belt 10 to a predetermined width and length and fixing both ends in the longitudinal direction of the belt with a jig or the like to make it endless, are arranged so as to face each other vertically. It is wound around 51, 52 and a pair of toothed pulleys 53, 54, respectively. A fixture 58 for fixing the loading platform 57 is attached to each toothed belt 10. Of the four toothed pulleys 51 to 54, one toothed pulley 52 is driven, and the remaining toothed pulleys 51, 53, 54 are synchronously driven via the toothed belt 10. When the toothed pulley 52 is rotated in the forward direction or the reverse direction while the conveyed object 59 is placed on the loading platform 57, the pair of toothed belts 10 travel and the conveyed object 59 moves up and down.

The toothed belt 10 is preferable for application to a heavy transported object. For example, the transported object 59 weighs 5 to 11 tons and has a maximum tension of 0.25 to 0.25 kN / mm. Can be used in the environment.
The toothed belt according to the present invention may be either open-ended or endless. Further, the toothed belt according to the present invention is not limited to being used for an elevating and lowering transport device, and may be used for any device. Further, the toothed belt of the present invention may be provided with a reinforcing cloth on the outer peripheral surface and / or the inner peripheral surface of the belt body.

Next, an example of a method for manufacturing the toothed belt 10 will be described.

The toothed belt 10 is manufactured by, for example, a manufacturing apparatus 60 as shown in FIG. The manufacturing apparatus 60 includes a forming drum 61, pulleys 62 and 63 arranged close to each other above and below the forming drum 61, pulleys 64 arranged horizontally facing the forming drum 61, and pulleys 62 to 64. It has a pressing band 65, which is a wound endless metal band, an extrusion head 66 that extrudes a thermoplastic elastomer, and a core wire supply device (not shown).

Grooves for forming the tooth portions 3 are formed on the outer peripheral surface of the molding drum 61 at predetermined intervals in the circumferential direction. The pulley 64 is movable in the horizontal direction with respect to the forming drum 61, and applies a predetermined tension to the pressing band 65. The pressing band 65 is arranged so as to wrap around the outer peripheral surface of the molding drum 61 about half a circumference, and is pressed against the outer peripheral surface of the molding drum 61 by applying tension from the pulley 64.

The extrusion head 66 supplies the thermoplastic elastomer in a molten state by heating to the outer peripheral surface of the molding drum 61. The core wire supply device (not shown) supplies a plurality of core wires 1 arranged in the axial direction of the forming drum 61 to the outer peripheral surface of the forming drum 61.

The molten thermoplastic elastomer and the plurality of core wires 1 supplied to the outer peripheral surface of the forming drum 61 are caught between the forming drum 61 and the pressing band 65 as the forming drum 61 rotates. At this time, the pressing force of the pressing band 65 fills the groove formed on the outer peripheral surface of the molding drum 61, and the tooth portion 3 is formed in the groove. At this time, a back surface portion 2 in which a plurality of core wires 1 are embedded is formed between the outer peripheral surface of the molding drum 61 and the pressing band 65. Then, the thermoplastic elastomer is cooled and solidified while being strongly pressed against the outer peripheral surface of the molding drum 61 by the pressing force of the pressing band 65. The belt body 10a is continuously taken out at a portion where the pressing band 65 is separated from the molding drum 61.

As described above, according to the present embodiment, as will be shown later in the examples, the belt width W can be suppressed and the load capacity can be increased, which is preferable for application to a heavy-weight conveyed object. The belt 10 can be provided.

In the present embodiment, each core wire 1 is made of a steel cord, has a strength of 7 to 8 kN, and has a diameter D of 2.3 to 2.6 mm. In this case, by using the steel cord having the features of low elongation and high strength as the core wire 1, it is possible to more reliably improve the belt strength per unit width.

In the present embodiment, the pitch Pt of the core wires 1 is 3.0 to 3.7 mm, and the distance d between the core wires 1 is 0.4 to 1.4 mm. In this case, as will be shown later in Examples, an improvement in belt strength per unit width can be more reliably realized by a suitable combination of pitch and spacing of the core wires 1.

In the above-mentioned manufacturing method, the present inventor uses an AT20 tooth mold (a tooth mold having a tooth pitch of 20 mm according to ISO17396: 2014) and a polyurethane (polyester type polyurethane) -based thermoplastic elastomer in Example 1. The toothed belts according to 9 and Comparative Examples 1 to 3 were manufactured, and a tensile test and a running test were performed on these toothed belts.

The configurations of the toothed belts according to Examples 1 to 9 and Comparative Examples 1 to 3 are shown in Tables 1 to 4 below.
The belt width W of the toothed belts of Examples 1 to 9 and Comparative Examples 1 to 3 was all 135 mm.

Here, in Table 1, in order to make a comparison when the pitch P of the tooth portion 3 and the belt strength per 1 mm of the belt width are varied, the configurations of the toothed belts of Examples 1 to 3 and Comparative Examples 1 to 3 are shown. It is described. Further, in Table 2, the configurations of the toothed belts of Examples 1, 4 and 5 are described in order to compare the case where the pitch Pt of the core wire 1 is variable with respect to the toothed belt of Example 1. There is. Further, in Table 3, the configurations of the toothed belts of Examples 1 and 6 to 8 are shown in order to compare the case where the hardness is variable with respect to the toothed belt of Example 1. Further, in Table 4, the configurations of the toothed belts of Examples 1 and 9 are shown in order to compare the case where the type of polyurethane is changed with respect to the toothed belt of Example 1.

(Comparison of variable tooth pitch P and belt strength)

(Comparison of variable pitch Pt of core wire)

(Comparison of variable hardness)

(Comparison with different types of polyurethane)

In the running test, test pieces 10x having a width of 20 mm and a length of 3700 mm were collected from the toothed belts according to Examples 1 to 9 and Comparative Examples 1 to 3, and both ends of each test piece 10x were taken as shown in FIG. Was joined by a joint 20 to be endless, and was wound around a drive pulley 71 and a driven pulley 72 (the number of teeth of each pulley 71, 72 = 32) of the elevating tester 70. Then, a tension of 0.25 kN / mm was applied to each test piece 10x, and 1 million cycles (one cycle in one round trip in the forward direction and the reverse direction indicated by the arrow in FIG. 5) were repeatedly run.

Then, for each test piece 10x, the strength of the test piece 10x before and after the running test (before and after running) is measured by a tensile test, and the rate of decrease in the strength of the test piece 10x before and after the running test is calculated. did. The results are shown in Tables 1 to 4 in the items of strength before running and strength after running, and items of reduction rate of strength.

In the tensile test, a tension of 20 mm in width and 500 mm in length was obtained from the test piece 10x before running and the test piece 10x after running collected from the toothed belts according to Examples 1 to 9 and Comparative Examples 1 to 3. Each test piece was sampled, and each tensile test piece was subjected to a tensile test (tensile speed 50 mm / min) using an Amsler tensile tester to measure the strength until it broke.

In addition, observe each test piece 10x after the running test, and if there is a problem such as "tooth chipping" or "tooth wear", check the state in the item of "state after running" in Tables 1 to 4. If there is no particular change, it is described as "no problem".

Further, before and after the running test, it was determined whether or not each test piece 10x had a positioning defect with respect to the drive pulley 71 and the driven pulley 72. Specifically, as shown in FIG. 5, after the running test, the positional deviation was read by a jig connected to the joint 20. This jig moves up and down along the graduated bar in conjunction with the running (up and down of the joint 20) of the belt (both ends of each test piece 10x are joined by the joint 20 to make it endless), and the scale of the jig is used. The distance at which the reading position deviated between before and after the start of the running test was measured. Then, if the misaligned distance is less than 3 mm, there is no misalignment, and if it is 3 mm or more, there is a misalignment. Item).

Based on the results of the above running test, each of the toothed belts according to Examples 1 to 9 and Comparative Examples 1 to 3 was ranked A to D according to the criteria shown in Table 5 below, and Tables 1 to 1 It is described in the item of "judgment" of Table 4.

When the pitch P of the tooth is 20 mm or more (the pitch P of the tooth is relatively large, the scale of the tooth accompanying the pitch P of the tooth (the length of the tooth in the longitudinal direction of the belt and the tooth height of the tooth) All of the toothed belts of Examples 1 to 3 having high strength (1.85 kN / mm or more) and high h3) were ranked A.

Comparative Example 1 is a toothed belt having high strength but having a tooth pitch P of 14 mm (the tooth scale is slightly smaller). If the scale of the tooth part due to the pitch P of the tooth part is small, the resistance to the effective tension (load) applied to one tooth is less than that of the tooth part having a large scale, so that the tooth part is easily deformed. It became impractical (D rank) due to the life due to early tooth chipping.

In Comparative Example 2, the pitch P of the tooth portion is 20 mm (the scale of the tooth portion is large), but the belt strength is 1.85 kN / mm because a core wire having a smaller diameter and a smaller strength than that of Example 1 is used. It is a belt with teeth that does not meet. In this case, when a large load is applied to the toothed belt, an extremely high tension is applied to each core wire due to the small diameter of the core wire, and as a result, the toothed belt stretches and becomes poorly positioned, which is impractical. It became (D rank).

Comparative Example 3 is a toothed belt having a tooth pitch P of 14 mm (the tooth scale is slightly smaller) and a belt strength of less than 1.85 kN / mm. In this case, tooth chipping occurred at an early stage, and positioning was poor, making it impractical (D rank).

In Examples 4 and 5, the pitch P of the tooth portion has the same configuration as that of Example 1 except that the pitch Pt of the core wire is variable (enlarged) to reduce the number of core wires embedded in the toothed belt. It is a 20 mm toothed belt (large scale of teeth). Although the belt strength is lower than that of Example 1 due to the reduction in the number of core wires, the belt strength of 1.85 kN / mm or more can be maintained even after running, and "tooth chipping" and "tooth wear". It was confirmed that it was practical (B rank) without any problems such as or poor positioning.

In Examples 6 to 8, the pitch P of the tooth portion is 20 mm (the scale of the tooth portion is 20 mm), which has the same configuration as that of Example 1 except that the hardness of the material (polyurethane-based thermoplastic elastomer) constituting the toothed belt is changed. Large) toothed belt. Example 8 (95 °) having a high hardness was ranked A, but a toothed belt having a low hardness was ranked B in Example 7 (85 °) because the tooth was easily worn due to the deformation of the tooth. In Example 6 (80 °), the rank was C.

Example 9 has the same configuration as that of Example 1 except that the type of polyurethane which is a material (polyurethane-based thermoplastic elastomer) constituting the toothed belt is changed, and the tooth pitch P is 20 mm (tooth scale). Is a large) toothed belt. In this case, the rank was A, which was the same as in Example 1.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as it is described in the claims.

-The toothed belt according to the present invention may be either open-ended or endless. Further, the toothed belt according to the present invention is not limited to being used for an elevating and lowering transport device, and may be used for any device.
-The thermoplastic elastomer is not limited to the polyurethane-based thermoplastic elastomer, and includes, for example, polyester-based thermoplastic elastomer, polystyrene-based thermoplastic elastomer, polyolefin-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, and the like. It may be present, or it may be a combination of two or more of these.
-The hardness of the thermoplastic elastomer is not limited to 85 to 95 ° and may be outside these ranges.
-The core wire is not limited to the steel cord, and may be, for example, a cord obtained by twisting aramid fibers or carbon fibers.
-A reinforcing cloth may be provided on the outer peripheral surface and / or the inner peripheral surface of the belt body.

1 core wire 2 back part 3 tooth part 10 toothed belt 10a belt body d core wire spacing D core wire diameter h2 back part thickness h3 tooth height p tooth pitch Pt core wire pitch

Claims (5)

A single- layer back portion extending in the longitudinal direction of the belt and having a plurality of core wires arranged in the width direction of the belt, facing the back portion in the thickness direction of the belt, and separated from each other in the longitudinal direction of the belt. A toothed belt comprising a belt body including a plurality of the tooth portions, and the back surface portion and the plurality of tooth portions are integrally molded with a thermoplastic elastomer .
The pitch of the previous Symbol plurality of teeth is not less 20mm or more,
The height of each of the plurality of teeth is 5 mm or more.
Ri der thickness 4mm or more of the rear portion,
The strength of the core wire is 7 to 8 kN.
The pitch of the plurality of core wires is 3.0 to 3.7 mm, and the pitch is 3.0 to 3.7 mm.
The distance between the plurality of core wires is 0.4 to 1.4 mm.
The belt strength per 1 mm of belt width of the toothed belt holds 1.85 kN or more.
A toothed belt characterized in that it is used in a usage environment where a maximum tension of 0.25 to 0.25 kN / mm is applied at a load capacity level . The belt according to claim 1, wherein each of the plurality of core wires comprises a cord obtained by twisting at least one of a steel cord, an aramid fiber, and a carbon fiber. Each of the plurality of core wires
Consists of steel cord
Toothed belt according to claim 1, wherein the diameter is 2.3～2.6Mm. The thermoplastic elastomer is selected from the group consisting of a polyurethane-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polystyrene-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, and a vinyl chloride-based thermoplastic elastomer. The belt according to any one of claims 1 to 3 , wherein the belt is at least one kind. The toothed belt according to any one of claims 1 to 4 , wherein the thermoplastic elastomer is a polyurethane-based thermoplastic elastomer and has a hardness of 85 to 95 °.