JP-7857167-B2 - Endless belt and method for manufacturing an endless belt

JP7857167B2JP 7857167 B2JP7857167 B2JP 7857167B2JP-7857167-B2

Inventors

永野広大
佐藤佑紀

Assignees

ニッタ株式会社

Dates

Publication Date: 20260512
Application Date: 20220614

Claims (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, 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.
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.
The endless belt according to claim 1 or 2, wherein the weft thread is formed of aramid fiber or glass fiber .
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.

Description

This invention relates to an endless belt and a method for manufacturing an endless belt. Endless belts used as high-speed transmission belts generally utilize a strip-shaped belt with a core layer. An endless belt has a joint where both ends of the strip-shaped belt are bonded together using adhesive or heat bonding. The ends of the strip-shaped belt have complementary shapes, such as finger shapes. Because the core layer is cut at the joint of the endless belt, its tensile strength is low. Therefore, endless belts have the problem of being prone to breakage starting at the joint. Therefore, in conventional endless belts comprising a core layer, an intermediate layer containing a thermoplastic resin, and a surface canvas layer, a technique is known in which a reinforcing sheet made of knitted fabric with voids penetrating in the thickness direction is embedded within the intermediate layer, spanning both ends of the joint (see, for example, Patent Document 1). According to the technology described in Patent Document 1, when a reinforcing sheet is embedded in the intermediate layer by heat bonding, the thermoplastic resin of the intermediate layer fills the voids. Therefore, it has the effect of firmly connecting both ends of the joint portion of the endless belt. However, the reinforcing sheet must have a certain degree of flexibility in the joint direction (belt longitudinal direction) of the joint portion; otherwise, it cannot smoothly follow the rotation of the drive pulley and drive the endless belt. Japanese Patent Publication No. 2021-102970 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 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.This is a schematic, partially enlarged cross-sectional view showing a cross-section of an endless belt according to an embodiment.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.This is a stepwise cross-sectional view showing the manufacturing method of the endless belt according to the embodiment, where Figure 5a shows the state with the reinforcing sheet installed, and Figure 5b shows the state with the separating part covered.This is a schematic diagram showing the usage state of the endless belt according to the embodiment.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 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. 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". This endless belt 10 is formed by joining the ends of a strip-shaped core layer 12 at a joint portion 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 portion 15 perpendicular to the joint direction is typically 10 mm to 5000 mm. The core layer 12 is formed from canvas using polyester fibers, nylon fibers, aramid fibers, or glass fibers as the warp and weft threads. The first intermediate layer 14 is laminated to one surface of the core layer 12, and the second intermediate layer 16 is laminated to the other surface of the core layer 12. The first intermediate layer 14 and the second intermediate layer 16 are formed from a thermoplastic resin. Specifically, examples of thermoplastic resins that can be used include polyurethane elastomer, polyamide elastomer, polyester elastomer, polyvinyl chloride elastomer, or polyolefin elastomer. The first surface layer 18 is laminated onto the surface of the first intermediate layer 14, and the second surface layer 20 is laminated onto the surface of the second intermediate layer 16. The first surface layer 18 and the second surface layer 20 function as protective materials for the core layer