Endless belt and method for manufacturing an endless belt

Abstract

To provide an endless belt which can further improve the strength of a joint part in a width direction without impairing the bending performance of the joint part of the endless belt in a joint direction, and a manufacturing method of the endless belt.SOLUTION: An endless belt comprises a band-shaped core body layer 12, a thermoplastic resin-made intermediate layer 14 laminated on at least one face of the core body layer 12, a surface layer 18 laminated on a surface of the intermediate layer 14, and a joint part at which a first end part and a second end part having complementary shapes are joined to each other. A reinforcing sheet 26 is embedded into the intermediate layer 14 over the joint part, the reinforcing sheet 26 has an air gap 28 penetrating in a thickness direction, and is composed of a woven fabric which is woven by wefts 262 whose tensile strength is higher than those of warps, and the tensile strength of the reinforcing sheet 26 is set so as to be higher in a width direction of the joint part than that in a joint direction of the joint part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an endless belt and a method for manufacturing the endless belt.

Background Art

[0002] As an endless belt for high-speed transmission, a belt-shaped belt having a core layer is generally used. The endless belt has a joint portion in which both ends of the belt-shaped belt are integrally adhered using an adhesive or heat adhesion. Both ends of the belt-shaped belt have complementary shapes to each other, for example, finger shapes. Since the joint portion of the endless belt is in a state where the core layer is cut, the tensile strength is small. Therefore, the endless belt has a problem that it is likely to break starting from the joint portion.

[0003] For this reason, conventionally, in an endless belt in which a core layer, an intermediate layer containing a thermoplastic resin, and a surface canvas layer are laminated, a reinforcing sheet made of a knitted fabric having voids penetrating in the thickness direction is embedded in the intermediate layer across both ends of the joint portion (see, for example, Patent Document 1).

[0004] According to the technique described in Patent Document 1, when the reinforcing sheet is embedded in the intermediate layer by performing heat adhesion, the void portion is filled with the thermoplastic resin of the intermediate layer. Therefore, there is an effect that both ends of the joint portion of the endless belt can be firmly connected. Here, if the reinforcing sheet does not have a certain degree of flexibility in the joint direction (belt longitudinal direction) of the joint portion, the endless belt cannot be driven while smoothly following the rotation of the driving pulley.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if the flexibility of the reinforcing sheet in the joint direction is prioritized, there is a problem in that it is not possible to sufficiently secure the strength in the width direction (belt width direction) perpendicular to the joint direction at the joint.

[0007] The present invention aims to provide an endless belt and a method for manufacturing an endless belt that can further improve the strength in the width direction of the joint portion without impairing the flexibility of the joint portion in the joint direction. [Means for solving the problem]

[0008] The endless belt according to the present invention comprises a strip-shaped core layer, an intermediate layer made of thermoplastic resin laminated on at least one surface of the core layer, a surface layer laminated on the surface of the intermediate layer, and a joint portion to which a first end and a second end having complementary shapes are joined, wherein a reinforcing sheet is embedded in the intermediate layer, spanning the joint portion, and the reinforcing sheet has voids penetrating in the thickness direction and is made of a woven fabric woven with a plurality of threads including a plurality of warp threads and a plurality of weft threads spanning the plurality of warp threads, and the reinforcing sheet is arranged such that the tensile strength of the reinforcing sheet is greater in the width direction of the joint portion spanning the joint direction than in the joint direction of the joint portion, and the reinforcing sheet is arranged such that the tensile strength of the reinforcing sheet is greater in the width direction of the joint portion spanning the joint direction than in the joint direction of the joint portion.

[0009] The present invention relates to a method for manufacturing an endless belt comprising a strip-shaped core layer, an intermediate layer made of thermoplastic resin laminated on at least one surface of the core layer, a surface layer laminated on the surface of the intermediate layer, and a joint portion to which a first end and a second end having complementary shapes are joined, wherein the method for manufacturing an endless belt comprises the steps of: making cuts in the intermediate layer at both ends of the strip-shaped core layer to separate the intermediate layer into a core layer side intermediate portion and a surface layer side intermediate portion; processing both ends of the endless belt into complementary shapes to form the first end and the second end; and having voids penetrating in the thickness direction, and a plurality of warp threads The method includes the steps of: placing a reinforcing sheet made of a woven fabric woven with multiple weft threads on the surface of the core layer side intermediate portion so as to span the first end and the second end; covering the reinforcing sheet with the surface layer side intermediate portion and the surface layer; heat bonding the surface layer side intermediate portion and the core layer side intermediate portion; filling the voids in the reinforcing sheet with thermoplastic resin; and embedding the reinforcing sheet in the intermediate layer, wherein the step of placing the reinforcing sheet is to place the reinforcing sheet such that the tensile strength of the reinforcing sheet is greater in the width direction of the joint portion that spans the joint direction than in the joint direction of the joint portion. [Effects of the Invention]

[0010] According to the present invention, by arranging the direction in which the tensile strength of the reinforcing sheet is greater in the width direction of the joint, the strength in the width direction of the joint can be further improved without impairing the flexibility of the joint in the joint direction. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1a is a plan view of the endless belt according to the embodiment, and Figure 1b is a cross-sectional view of the endless belt according to the embodiment along the line 1b-1b shown in Figure 1a. [Figure 2] Figure 2a is a plan view of the reinforcing sheet according to the embodiment, and Figure 2b is a cross-sectional view of the reinforcing sheet according to the embodiment. [Figure 3] This is a schematic, partially enlarged cross-sectional view showing a cross-section of an endless belt according to an embodiment. [Figure 4]This is a stepwise cross-sectional view showing the manufacturing method of the endless belt according to the embodiment, with Figure 4a showing the belt before the cut and Figure 4b showing the belt after the cut. [Figure 5] This is a stepwise cross-sectional view showing the manufacturing method of the endless belt according to the embodiment, with Figure 5a showing the state with the reinforcing sheet installed and Figure 5b showing the state with the separation part covered. [Figure 6] This is a schematic diagram showing the usage state of the endless belt according to the embodiment. [Figure 7] Figure 7a is a plan view of a modified reinforcing sheet of the embodiment, and Figure 7b is a cross-sectional view of the reinforcing sheet. [Figure 8] Figure 8a is a plan view of a modified reinforcing sheet of the embodiment, and Figure 8b is a cross-sectional view of the reinforcing sheet. [Modes for carrying out the invention]

[0012] The embodiments of the present invention will be described in detail below with reference to the drawings. (Overall structure) Figure 1 shows an endless belt 10 according to this embodiment, where Figure 1a is a plan view of the endless belt and Figure 1b is a cross-sectional view of the endless belt 10 in the thickness direction. In the following description, as shown in Figures 1a and 1b, the longitudinal direction of the belt will be referred to as the x-direction and called the "joint direction", the belt width direction perpendicular to the longitudinal direction will be referred to as the y-direction and called the "width direction", and the z-direction will be referred to as the "thickness direction".

[0013] This endless belt 10 is formed by joining the ends of a strip-shaped core layer 12 at a joint 15, and comprises a core layer 12, a first intermediate layer 14, a second intermediate layer 16, a first surface layer 18, and a second surface layer 20. The thickness of the endless belt 10 is typically 0.5 mm to 10.0 mm, and the width of the joint 15 perpendicular to the joint direction is typically 10 mm to 5000 mm.

[0014] The core layer 12 is formed from canvas using polyester fibers, nylon fibers, aramid fibers, or glass fibers as raw materials for the warp and weft threads.

[0015] The first intermediate layer 14 is laminated on one surface of the core layer 12, and the second intermediate layer 16 is laminated on the other surface of the core layer 12. The first intermediate layer 14 and the second intermediate layer 16 are formed of a thermoplastic resin. Specifically, as the thermoplastic resin, for example, polyurethane elastomer, polyamide elastomer, polyester elastomer, polyvinyl chloride-based elastomer, or polyolefin-based elastomer can be used.

[0016] The first surface layer 18 is laminated on the surface of the first intermediate layer 14, and the second surface layer 20 is laminated on the surface of the second intermediate layer 16. The first surface layer 18 and the second surface layer 20 function as protective materials for protecting the core layer 12, and are formed of rubber, resin, canvas, or synthetic leather.

[0017] Specifically, as the rubber constituting the first surface layer 18 and the second surface layer 20, for example, mirable urethane, nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), or chlorosulfonated polyethylene can be used. As the resin, polyurethane elastomer, polyamide elastomer, polyester elastomer, polyvinyl chloride-based elastomer, or polyolefin-based elastomer can be used. As the canvas, for example, canvas using fibers such as polyester fiber or nylon fiber can be used. Note that the second surface layer 20 may be the same as or different from the material of the first surface layer 18.

[0018] The endless belt 10 has a joint portion 15. The joint portion 15 is a finger joint. The joint portion 15 has a first end portion 22 and a second end portion 24 in a joined state. The first end portion 22 includes the tip in the joint direction of a belt-like belt (not shown). The second end portion 24 includes the base end in the joint direction of a belt-like belt (not shown). The endless belt 10 joins the first end portion 22 and the second end portion 24 to form an endless shape.

[0019] The first end portion 22 and the second end portion 24 each have a plurality of complementary concave portions 19 and convex portions 21. The concave portions 19 are isosceles triangles and right triangles recessed inward in the joint direction of the endless belt 10. The convex portions 21 are isosceles triangles protruding outward in the joint direction. The first end portion 22 and the second end portion 24 have a saw blade shape in which a plurality of concave portions 19 and convex portions 21 are formed. The length in the width direction of the concave portions 19 and the convex portions 21 is 5 mm to 30 mm, and the length in the joint direction of the concave portions 19 and the convex portions 21 is 5 mm to 250 mm.

[0020] The first intermediate layer 14 of the endless belt 10 has a reinforcing sheet 26 at a position straddling the boundary between the first end portion 22 and the second end portion 24. The reinforcing sheet 26 is disposed in a region wider than the range from the proximal end 23 of the concave portion 19 of the first end portion 22 to the proximal end 25 of the concave portion 19 of the second end portion 24. The length in the width direction of the reinforcing sheet 26 is set to about +0 mm to -1 mm with respect to the length in the width direction of the endless belt 10. The length in the joint direction of the reinforcing sheet 26 is about 20 mm larger than the length in the joint direction of the concave portion 19 or the convex portion 21, and about 30 mm larger than the length of the joint portion 15.

[0021] As shown in FIGS. 2a and 2b, the reinforcing sheet 26 is composed of a plain woven fabric in which warp threads 261 and weft threads 262 are alternately woven vertically in the thickness direction. A plurality of voids 28 penetrating in the thickness direction (z direction) of the reinforcing sheet 26 are formed in the region surrounded by the warp threads 261 and the weft threads 262. The warp threads 261 are arranged to extend along the joint direction (x direction) of the joint portion 15. The weft threads 262 are arranged to extend along the width direction (y direction) of the joint portion 15 straddling the joint direction of the joint portion 15. The voids 28 are formed in each rectangular region surrounded between parallel warp threads 261 and between parallel weft threads 262, respectively. In the present embodiment, a square region with the same density of the warp threads 261 and the weft threads 262 is defined as the void 28, and the void 28 is formed at the position where the warp threads 261 and the weft threads 262 intersect.

[0022] For the warp threads 261, polyester fibers, nylon fibers, cotton, etc., which have good flexibility are used. For the weft threads 262, the diameter may be the same as the warp threads 261 or may be different, but for example, aramid fibers, glass fibers, etc., which have high tensile strength are used and are formed to have a higher tensile strength than the warp threads 261. For this reason, the reinforcing sheet 26 is embedded in the first intermediate layer 14 with the direction in which the warp threads 261 stretch in the joint direction and the direction in which the weft threads 262, which have a higher tensile strength than the warp threads 261, stretch in the width direction, so that the tensile strength in the width direction (y direction) is greater than the tensile strength in the joint direction (x direction) of the joint portion 15. Note that the warp threads 261 and weft threads 262 may be single threads or may be composed of multiple threads such as double threads.

[0023] As shown in Figure 3, the first intermediate layer 14 comprises a surface layer-side intermediate portion 27 positioned on the first surface layer 18 side of the reinforcing sheet 26, and a core layer-side intermediate portion 29 positioned on the core layer 12 side of the reinforcing sheet 26. The surface layer-side intermediate portion 27 and the core layer-side intermediate portion 29 are connected by the thermoplastic resin constituting the first intermediate layer 14 in the voids 28 of the reinforcing sheet 26. In other words, the thermoplastic resin of the first intermediate layer 14 fills the voids 28 of the reinforcing sheet 26, and the reinforcing sheet 26 is integrated with the first intermediate layer 14.

[0024] The reinforcing sheet 26 has a void ratio 28 per unit area of ​​35% or more and 70% or less when viewed in the thickness direction. If the void ratio 28 is 70% or less, the reinforcing sheet 26 has sufficient strength. If the void ratio 28 is 35% or more, the intermediate portion 27 on the surface layer side and the intermediate portion 29 on the core layer side are sufficiently integrated, and delamination between the first intermediate layer 14 and the reinforcing sheet 26 can be suppressed.

[0025] Furthermore, the reinforcing sheet 26, when embedded in the first intermediate layer 14, is approximately 50% of the thickness of the first intermediate layer 14. If the thickness of the reinforcing sheet 26 significantly exceeds 50% of the thickness of the first intermediate layer 14, the flexibility of the reinforcing sheet 26 will be impaired, and there is a possibility that the reinforcing sheet 26 may fall out of the first intermediate layer 14 while the endless belt 10 is being driven. If the thickness of the reinforcing sheet 26 significantly falls below 50% of the thickness of the first intermediate layer 14, its effectiveness as a reinforcing material will be impaired, and the strength of the endless belt 10 cannot be sufficiently improved.

[0026] (Manufacturing method) Next, the manufacturing method of the endless belt 10 described above will be explained. As shown in Figure 4a, a notch is made in the first intermediate layer 14 of the first end 22 and the second end 24 before joining, in the direction of the joint from the tip, to form a notched portion 32. Figure 4a shows the first end 22 as a representative example. The notched portion 32 is formed parallel to the joint direction of the joint portion 15. The length of the notched portion 32 in the joint direction is longer than the length in the longitudinal direction of the recess 19 and protrusion 21 that will be formed later. It is preferable to form the notched portion 32 at the center position in the thickness direction of the first intermediate layer 14. After the notched portion 32 is formed, the first intermediate layer 14 is separated into a surface layer side intermediate portion 27 that is integrated with the first surface layer 18 and a core layer side intermediate portion 29 that is integrated with the core layer 12.

[0027] As shown in Figure 4b, a separation portion 33 is formed at the first end portion 22 after the notch portion 32 has been formed, consisting of a first surface layer 18 and a surface layer-side intermediate portion 27. The separation portion 33 can be folded back in a direction that separates the surface layer-side intermediate portion 27 and the core layer-side intermediate portion 29. The direction in which the surface layer-side intermediate portion 27 and the core layer-side intermediate portion 29 separate is the direction in which the tip of the separation portion 33 is bent toward the surface of the first surface layer 18. Although not shown, a separation portion 33 is similarly formed at the second end portion 24 after the notch portion 32 has been formed.

[0028] Using known tools, the first end 22 and the second end 24 are machined to form a plurality of recesses 19 and protrusions 21, respectively. The range in the joint direction in which the recesses 19 and protrusions 21 are formed is narrower than the area in which the notches 32 are formed. With the first surface layer 18 facing upward, the first end 22 and the second end 24 are butted together, combining their respective recesses 19 and protrusions 21.

[0029] As shown in Figure 5a, with the separation portion 33 folded back, the reinforcing sheet 26 is placed on the core layer-side intermediate portion 29 so as to straddle the boundary between the first end portion 22 and the second end portion 24. The reinforcing sheet 26 is placed beyond the area where the recess 19 and convex portion 21 are formed, and within the area where the cut portion 32 is formed. Furthermore, the reinforcing sheet 26 is positioned such that the direction in which the warp threads 261 extend is the joint direction of the joint portion 15, and the direction in which the weft threads 262, which have a greater tensile strength than the warp threads 261 and are arranged perpendicular to the warp threads 261, extend is the width direction of the joint portion 15.

[0030] As shown in Figure 5b, the reinforcing sheet 26 is covered with the separation portion 33, and the intermediate portion 27 on the surface layer side is brought into contact with the surface of the reinforcing sheet 26. The recesses 19 and protrusions 21 of the separation portions 33 are brought together and butted. In this state, the region in which at least the notches 32 are formed, centered on the first end portion 22 and the second end portion 24, is heat-bonded while applying pressure in the thickness direction. By heating, the thermoplastic resins of the first intermediate layer 14 and the second intermediate layer 16 melt, and the tips of the first end portion 22 and the second end portion 24 fuse together.

[0031] In the first intermediate layer 14, the molten thermoplastic resin in the intermediate portion 27 on the surface layer side and the intermediate portion 29 on the core layer side flows through the voids 28 of the reinforcing sheet 26 and fuses with each other through the voids 28. As the thermoplastic resin cools and solidifies, the first intermediate layer 14 and the second intermediate layer 16 become one unit between the first end 22 and the second end 24.

[0032] The surface layer-side intermediate portion 27 and the core layer-side intermediate portion 29 are integrated via the gap 28 in the reinforcing sheet 26. As a result, the first intermediate layer 14 holds the reinforcing sheet 26 at a position that straddles the boundary between the first end portion 22 and the second end portion 24. In this way, an endless belt 10 can be obtained in which the reinforcing sheet 26 is embedded in the first intermediate layer 14.

[0033] (Mechanism of Action and Effects) As shown in Figure 6, the endless belt 10 is wound around the drive pulley 30 such that the second surface layer 20 and the surface of the drive pulley 30 are in contact, and can be used as a transmission belt or a conveyor belt. The surface layer side intermediate portion 27 and the core layer side intermediate portion 29 of the first intermediate layer 14 are integrally connected through the voids 28 of the reinforcing sheet 26, so that the first intermediate layer 14 is more firmly bonded to the reinforcing sheet 26. Therefore, the endless belt 10 can suppress delamination between the reinforcing sheet 26 and the first intermediate layer 14 and further improve the strength of the joint portion 15. The strength of the joint portion 15 can be more reliably improved by having a ratio of voids 28 per unit area, viewed from the thickness direction, of 35% to 70%.

[0034] In addition, the reinforcing sheet 26 according to this embodiment is composed of a plain weave fabric woven with a plurality of warp threads 261 and a plurality of weft threads 262 that have a greater tensile strength than the warp threads 261 and span across the warp threads 261. This makes it possible to have different tensile strengths of the reinforcing sheet 26 in the direction in which the warp threads 261 stretch and in the direction in which the weft threads 262 stretch. Therefore, in the endless belt 10, by arranging the direction in which the reinforcing sheet 26 has a greater tensile strength in the width direction of the joint portion 15, the tensile strength in the width direction of the joint portion 15 can be further improved without impairing the flexibility of the joint portion 15 in the joint direction. In particular, by using polyester fibers, nylon fibers, cotton, etc. for the warp threads 261, the flexibility of the joint portion 15 of the endless belt 10 in the joint direction is not impaired.

[0035] (Variations of the embodiment) It should be noted that the present invention is not limited to the embodiments described above, but also includes the following modifications. In the embodiments described above, the first intermediate layer 14 and the first surface layer 18 shown in Figure 1b were applied as an intermediate layer in which a reinforcing sheet is embedded across the joint and as a surface layer laminated on the surface of the intermediate layer. However, the present invention is not limited to this, and the second intermediate layer 16 and the second surface layer 20 shown in Figure 1b may also be applied.

[0036] Furthermore, in the embodiments described above, a reinforcing sheet was applied in which a plurality of weft threads having greater tensile strength than the warp threads are arranged in a direction that straddles the joint direction of the joint portion, and the tensile strength in the width direction is greater than the tensile strength in the joint direction. In contrast, a reinforcing sheet 26 was applied in which a plurality of weft threads having greater tensile strength than the warp threads 261 are arranged along the width direction (y direction) that straddles the joint direction (x direction) of the joint portion 15 perpendicularly, and the tensile strength in the width direction is greater than the tensile strength in the joint direction. However, the present invention is not limited to these embodiments. As another embodiment, for example, a reinforcing sheet may be applied in which a plurality of weft threads having greater tensile strength than the warp threads 261 are arranged in a direction (y direction) that straddles the joint direction (x direction) of the joint portion 15 at an acute or obtuse angle, and the tensile strength in the width direction is greater than the tensile strength in the joint direction. Furthermore, as an alternative reinforcing sheet, the warp threads 261 do not necessarily have to be arranged along the joint direction of the joint portion 15. Instead, a reinforcing sheet may be applied in which the warp threads are arranged at an acute angle from the joint direction, and the tensile strength in the width direction is greater than the tensile strength in the joint direction.

[0037] Furthermore, in the above-described embodiment, a reinforcing sheet 26 was applied as a reinforcing sheet composed of a plain weave fabric woven with a plurality of warp threads 261 and a plurality of weft threads 262, which includes at least a plurality of warp threads and a plurality of weft threads that cross over the warp threads. However, the present invention is not limited to this, and a reinforcing sheet composed of a fabric woven with a plurality of threads including a plurality of warp threads and a plurality of weft threads using various knitting methods may also be applied. For example, as shown in Figures 7a and 7b, the reinforcing sheet 40 may be composed of a twill weave fabric. The warp threads 401 of the reinforcing sheet 40 are passed so as to cross over two weft threads 402 on the lower surface and then cross over two weft threads 402 on the upper surface, and this is repeated for a plurality of weft threads 402 perpendicular to the warp threads 401. Also, a twill weave reinforcing sheet 40 can be obtained by weaving the weft threads 402 in the same way as the warp threads 401.

[0038] Furthermore, as shown in Figures 8a and 8b, the reinforcing sheet 42 may be made of a satin weave fabric. The warp threads 421 of the reinforcing sheet 42 are passed over four weft threads 422 on the upper surface and then over one weft thread 422 on the lower surface, and this is repeated for multiple weft threads 422 perpendicular to the warp threads 421. Also, by weaving the weft threads 422 in the same way as the warp threads 421, a satin weave reinforcing sheet 42 can be obtained.

[0039] Even with such reinforcing sheets 40 and 42, similar to the embodiments described above, it is possible to create reinforcing sheets 40 and 42 in which the tensile strength in the width direction is greater than the tensile strength in the joint direction by using multiple weft threads 402 and 422, which have greater tensile strength than the warp threads 401 and 421, thereby achieving the same effects as the embodiments described above.

[0040] In the embodiments described above, the density (number) of the warp threads 261 and weft threads 262 of the reinforcing sheet 26 was formed to be the same in the joint direction and the width direction, but the present invention is not limited thereto. For example, the density of the weft threads may be made greater than the density of the warp threads to further improve the tensile strength in the width direction of the joint and further improve the flexibility in the joint direction. In such a configuration, even if the tensile strength of the warp threads 261 and weft threads 262 is the same, by making the density of the weft threads greater than the density of the warp threads, a reinforcing sheet can be realized in which the tensile strength in the width direction is greater than the tensile strength in the joint direction, and the same effects as in the embodiments described above can be achieved.

[0041] In the above-described embodiment, the warp threads 261 and weft threads 262 of the reinforcing sheet 26 had the same diameter, but the present invention is not limited to this. For example, a woven fabric in which the diameter of the weft threads 262 is larger than the diameter of the warp threads 261 may be used as the reinforcing sheet. In such a configuration, even if the warp threads 261 and weft threads 262 are made of the same material, by making the diameter of the weft threads larger than the diameter of the warp threads, it is possible to realize a reinforcing sheet in which the tensile strength in the width direction is greater than the tensile strength in the joint direction, and the same effects as in the above-described embodiment can be achieved.

[0042] In the embodiments described above, the reinforcing sheet 26 was woven with warp threads 261 and weft threads 262 perpendicular to each other, but the present invention is not limited thereto. For example, a reinforcing sheet may be used in which the weft threads intersect the warp threads diagonally. Furthermore, the specific structure and shape of the present invention may be other structures, etc., as long as the objectives of the present invention can be achieved. [Explanation of Symbols]

[0043] 10 Endless belt 12 Cardiac layer 14. First Meso-Marginal Layer (Meso-Marginal Layer) 15 Joint section 18 1st surface layer (surface layer) 19 Recess 20 2nd surface layer 21 Convex part 26, 40, 42 Reinforcement sheets 27 Intermediate part on the surface layer side 28 void 29. Intermediate part of the cardio-body layer 32 Cut section 261, 401, 421 warp threads 262, 402, 422 weft threads

Claims

1. A band-like layer of the heart and body, An intermediate layer made of thermoplastic resin is laminated on at least one surface of the core layer, A surface layer laminated on the surface of the intermediate layer, An endless belt comprising a joint portion to which a first end and a second end having complementary shapes are joined, In the aforementioned intermediate layer, a reinforcing sheet is embedded across the joint portion. The reinforcing sheet has voids penetrating in the thickness direction and is made of a woven fabric woven with at least a plurality of threads including a plurality of warp threads arranged in the joint direction of the joint portion and a plurality of weft threads arranged in the width direction of the joint portion and spanning the plurality of warp threads, wherein the density of the plurality of weft threads is greater than the density of the plurality of warp threads. An endless belt in which the reinforcing sheet is arranged such that the tensile strength of the reinforcing sheet is greater in the width direction of the joint portion, which spans the joint direction, than in the joint direction of the joint portion.

2. The endless belt according to claim 1, wherein the reinforcing sheet has weft threads with greater tensile strength than the warp threads, arranged in a direction that spans the joint direction of the joint portion.

3. The endless belt according to claim 1 or 2, wherein the weft is made of aramid fiber or glass fiber.

4. A band-like layer of the heart and body, An intermediate layer made of thermoplastic resin is laminated on at least one surface of the core layer, A surface layer laminated on the surface of the intermediate layer, A method for manufacturing an endless belt, comprising a joint portion to which a first end and a second end having complementary shapes are joined, The process involves making cuts in the intermediate layer at both ends of the band-shaped core layer to separate the intermediate layer into a core layer-side intermediate portion and a surface layer-side intermediate portion, The process of forming the first end and the second end of the endless belt by processing both ends of the endless belt into complementary shapes, A step of placing a reinforcing sheet, which has voids penetrating in the thickness direction and is made of a woven fabric woven with a plurality of warp threads arranged in the joint direction of the joint and a plurality of weft threads arranged in the width direction of the joint, wherein the density of the plurality of weft threads is greater than the density of the plurality of warp threads, on the surface of the intermediate portion on the core layer side so as to span the first end and the second end, The process includes covering the reinforcing sheet with the intermediate portion on the surface layer side and the surface layer, heat-bonding the intermediate portion on the surface layer side and the intermediate portion on the core layer side, filling the voids in the reinforcing sheet with thermoplastic resin, and embedding the reinforcing sheet in the intermediate layer. A method for manufacturing an endless belt, comprising the step of arranging the reinforcing sheet, wherein the reinforcing sheet is arranged such that the tensile strength of the reinforcing sheet is greater in the width direction of the joint portion, which spans the joint direction, than in the joint direction of the joint portion.

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