Method for producing a polyv belt

Abstract

The present application provides a kind of production method of multi-ribbed belt, first carry out the splicing of sheet cloth, make the two end portions of sheet cloth relative seamless alignment and form cylindrical, adopt adhesive tape to fix the two end portions of cloth in the inside of cylindrical cloth, form cylindrical cloth, put cylindrical cloth on forming hub, wind top rubber, string and bottom rubber on it and form rubber belt blank, rubber belt blank is demoulded from forming hub and forms cylindrical belt blank, tear off the adhesive tape inside the inside of cylindrical belt blank, put cylindrical belt blank into the cavity between outer mold and inner mold of vulcanization mold, carry out vulcanization by heating and pressurizing expansion, form vulcanization belt cylinder, take out vulcanization belt cylinder and carry out cutting forming, form multi-ribbed belt, the multi-ribbed belt produced by using the production method of multi-ribbed belt, there is no step difference on the surface of multi-ribbed belt, and simultaneously reduce the production and subsequent noise problem caused by sewing thread.

Description

Technical Field

[0001] This invention relates to a method for producing multi-wedge belts. Background Technology

[0002] Multi-ribbed belts generally consist of a top rubber, cords, and a bottom rubber. Various fabrics are typically applied to the outer side of the top rubber, i.e., the back of the belt, to meet different performance requirements, such as increasing abrasion resistance, reducing noise, or increasing load capacity. The ends of the fabric are overlapped, as described in US Patent No. 6238314B1. This results in a thicker overlap, causing periodic noise during transmission due to uneven thickness. To improve this, the fabric is typically sewn, woven, or knitted into a tubular structure. However, woven or knitted fabrics have limited structural options and may not meet all performance requirements. Tubular fabrics are usually sewn by folding and aligning the two sides. Overly tight sewing can create a bulge at the fabric joint. This bulge prevents the fabric from effectively stretching during production, resulting in a raised area at the fabric joint after vulcanization. If the stitching is too loose, gaps will appear at the seams, and after vulcanization, the multi-ribbed tape will form pits at the seams. Therefore, the stability of the sewing equipment and personnel is crucial, requiring significant effort in production control; otherwise, noise problems will arise. Furthermore, trimming is necessary after sewing, resulting in material waste. Additionally, the stitches in this structure are easily exposed during use, causing wear and breakage during contact with the pulley. To improve these stitching issues, patent CN106246802B employs a knurled structure where extrusion during vulcanization further flows the adhesive to cover the stitches, thus improving the defects at the stitching and joints to some extent.

[0003] Manufacturers have made various efforts to improve the fabric splice problem, but certain technologies are still needed to further improve or optimize the existing problems. Summary of the Invention

[0004] This invention provides a method for producing multi-wedge belts to solve the above technical problems. First, the two ends of a sheet of fabric are seamlessly aligned to form a tubular shape. Adhesive tape is used to fix the two ends of the fabric inside the tubular shape to form a tubular fabric. Second, the tubular fabric is placed on a molding hub, and top rubber, cord, and bottom rubber are wound around it to form a rubber strip blank. Next, the rubber strip blank is demolded from the molding hub to form a tubular strip blank. Then, the adhesive tape on the inside of the tubular strip blank is removed. Next, the tubular strip blank is placed in the cavity between the outer and inner molds of a vulcanizing mold, and vulcanized by heating and pressurizing to form a vulcanized strip tube. Finally, the vulcanized strip tube is removed and cut to form a multi-wedge belt.

[0005] The adhesive tape is a cloth-based tape.

[0006] The inner mold includes a mandrel and an air bladder fitted on the outer surface of the mandrel, and the inner surface of the outer mold is provided with ribs extending in the circumferential direction.

[0007] The splicing of the aforementioned sheet fabric is completed using a multi-wedge belt splicing device. This device includes a support frame, an upper suction plate, a lower support plate, a support plate, and a leveling mechanism. The two ends of the upper suction plate are rotatably mounted on the upper crossbeam at the top of the support frame. The leveling mechanism is fixedly mounted on the lower crossbeam of the support frame. The support plate is fixedly mounted on the leveling mechanism. The lower support plate is detachably mounted on the support plate. The leveling mechanism and the lower support plate are located on opposite sides of the support plate. The leveling mechanism can drive the support plate to move up and down. The upper suction plate is located above the lower support plate. The upper suction plate is a vacuum suction plate with a working surface. There are two symmetrical upper suction plates. When the two upper suction plates are flipped open to both sides, the two ends of the sheet fabric are aligned with the edges of the upper suction plates, allowing it to adhere to the upper suction plates. Then, the lower support plate with adhesive tape is placed on the support plate. Then, the upper suction plate flips inward, and the leveling mechanism lifts the lower support plate to move upward to the upper suction plate, pressing the adhesive tape to the ends of the fabric. Finally, the upper suction plate is de-aired and flipped outward to remove the tubular fabric.

[0008] The multi-wedge belt produced using this production method has good splicing position and no step difference. After vulcanization, the splicing marks are basically invisible on the surface of the multi-wedge belt. At the same time, since the tape is removed before vulcanization, there is no unevenness caused by adhesive at the seam, and the production and subsequent noise problems caused by the sewing are reduced. Attached Figure Description

[0009] Figure 1 Schematic diagram of the cross-section of the multi-wedge band.

[0010] Figure 2 A schematic diagram of the tubular fabric formed by splicing.

[0011] Figure 3 A three-dimensional schematic diagram of the fabric sleeve splicing equipment.

[0012] Figure 4 Axonometric view of a fabric splicing equipment.

[0013] Figure 5 Schematic diagram of the upper suction plate.

[0014] Figure 6 Schematic diagram of the splicing equipment operation.

[0015] Figure 7 A three-dimensional schematic diagram of a cylindrical strip billet.

[0016] Figure 8 A partial cross-sectional view of a cylindrical strip billet being loaded into a vulcanizing device.

[0017] To clearly illustrate the relationships between the parts, the parts in the attached drawings are not drawn to scale, and some parts have been enlarged in terms of area and thickness.

[0018] Explanation of reference numerals in the attached figures:

[0019] 1. Upper suction plate; 2. Bracket; 3. Lower support plate; 4. Leveling mechanism; 5. Support plate; 11. Air hole; 12. Longitudinal channel; 13. Transverse channel; 14. Fixing hole; 15. Adhesive tape; 21. Upper crossbeam of bracket; 22. Lower crossbeam of bracket; 23. Connecting seat; 31. Centerline; 41. Cylinder guide rod; 42. Guide post; 43. Fixing plate; 44. Cylinder; 45. Connecting plate; 46. Guide sleeve; 100. Fabric; 101. Flipping shaft; 111. Handle; 200. Multi-wedge belt; 201. Base rubber; 202. Rope; 203. Top rubber; 204. Back fabric; 200'. Cylindrical strip blank; 201'. Base rubber; 203'. Top rubber; 204'. Cylindrical fabric; 301. Core rod; 302. Airbag; 400. Outer mold. Detailed Implementation

[0020] like Figure 1 As shown, the multi-wedge tape 200 includes a base adhesive 201, a wedge formed on the base adhesive 201 extending in a circumferential direction, a top adhesive 203, a cord 202 located between the top adhesive 203 and the base adhesive 201, and a backing fabric 204 on the back of the top adhesive 203. Furthermore, the outer surface of the base adhesive 201 may also be covered with a wedge fabric, such as textiles or knitted fabric. The materials and processing methods of the backing fabric 204, top adhesive 203, cord 202, etc., are not limited and can be any materials disclosed in the prior art.

[0021] The following will refer to Figure 2-8 This describes a production method for multi-ribbed belts, which employs a molding process.

[0022] In this invention, the mixing and calendering of the base rubber and top rubber can be carried out using any process disclosed in the prior art, which will not be described in detail in this invention.

[0023] First, the sheet fabrics are spliced ​​together. These sheet fabrics are generally treated fabrics, including washing with hot water or chemicals, heat setting, or bonding treatments. For bonding treatments, to improve the fabric's adhesion to rubber materials or to obtain desired performance characteristics, additional treatments are usually applied to the fabric using gum arabic, adhesives such as resorcinol-formaldehyde latex (RFL), and resins (e.g., phenol or fluorinated resins). In some cases, processes such as rubbing or pasting may be performed. The treated fabric is then cut into sheet fabrics as needed; depending on the desired fabric texture, the cut may be straight or bias-cut. During splicing, the two ends of the fabric 100 are butt-jointed and seamlessly aligned to form a tubular shape; adhesive tape is used inside the tubular fabric to secure the two ends together. Figure 2 As shown, a seamless tubular fabric 204' is formed. Preferably, the splicing is performed on a multi-wedge tape splicing device, and the two ends of the fabric are bonded together using an adhesive tape to form a seamless tubular fabric, with the adhesive tape 15 located inside the tubular fabric. Since the adhesive tape mainly adheres to the surface of the fabric, a fabric-based tape with strong adhesion is preferred, and the width of the fabric-based tape is preferably less than 30 mm and the thickness is preferably less than 0.5 mm.

[0024] like Figures 3-4 As shown, the multi-wedge belt splicing equipment includes a stable support 2 assembled or welded from several crossbeams and longitudinal beams. Two upper suction plates 1 are symmetrically installed on the top of the support 2. One side of each upper suction plate 1 is a working surface, and two protruding parts are provided on the side perpendicular to the working surface. These protruding parts are preferably located near the two ends. Each of the two protruding parts has a coaxial through hole extending along the length of the upper suction plate 1. The shaft containing the through hole is a flip shaft 101. The upper suction plate 1 is fixed to a connecting seat 23 by a pin. The connecting seat 23 is installed on the upper crossbeam 21 of the support. The upper suction plate 1 can rotate around the pin or the flip shaft 101. A leveling mechanism 4 is fixedly installed at the lower part of the support. Specifically, the leveling mechanism 4 is fixedly installed on the lower crossbeam 22 of the support by a fixing plate 43. The upper crossbeam 21 and the lower crossbeam 22 are arranged vertically. To facilitate the operation of the leveling mechanism 4, the upper crossbeam 21 can be divided into two symmetrical groups. The leveling mechanism 4 includes a lifting device, a pair of guide sleeves 46 arranged on both sides of the lifting device and parallel to the lifting device, and guide columns 42 arranged inside the guide sleeves 46 and slidable up and down relative to the guide sleeves 46. The guide sleeves 46 and the lifting device are both fixedly mounted on a fixed plate 43. A connecting plate 45 is installed at the upper end of the lifting device and the guide columns. The connecting plate 45 moves up and down relative to the fixed plate 43 through the up and down movement of the lifting device and the lifting and lowering of the guide columns. A support plate 5 is fixedly mounted on the top of the lifting device, and the up and down movement of the lifting device drives the support plate 5 to move up and down.

[0025] The lifting device can be two devices installed at the front and back, or one device can be installed to ensure consistent operation, which simultaneously lifts the support plate 5.

[0026] The lifting device can be a manual device, that is, the lifting is achieved by rotating the lead screw relative to the nut. The nut is fixedly installed on the fixed plate 43, the upper end of the lead screw is rotatably installed on the connecting plate 45, and the other end of the lead screw extends downward out of the nut and is connected to the handle for easy operation.

[0027] Preferably, the lifting device is a pneumatic device. The preferred lifting device is a lifting cylinder, which includes a cylinder 44 fixed on a fixed plate 43 and a linearly moving cylinder guide rod 41. The cylinder guide rod 41 is arranged parallel to the guide posts 42 on both sides. The upper ends of the cylinder guide rod 41 and the guide posts 42 on both sides are fixed to a connecting plate 45. The cylinder 44 drives the cylinder guide rod 41 to extend or retract, causing the guide posts 42 to move up and down, thereby causing the connecting plate 45 to move up and down. A support plate 5 is fixedly installed on the connecting plate 45. The lower support plate 3 is detachably installed on the support plate 5. The leveling mechanism 4 and the lower support plate 3 are located on opposite sides of the support plate. The upper suction plate 1 is located above the lower support plate 3. The upper suction plate 1 is a vacuum suction plate with a working surface. When the upper suction plate 1 rotates inward around the rotation axis, the working surface of the upper suction plate 1 is parallel to the lower support plate 3 and close to each other. When the upper suction plate 1 rotates outward around the rotation axis, the working surface of the upper suction plate 1 and the lower support plate 3 move away from each other. In order to prevent the upper suction plate from having too large a gap with the lower support plate 3 after rotating during operation, which would prevent the fabric joint from being pressed tightly, the leveling mechanism moves upward to eliminate the gap.

[0028] The upper suction plate 1 preferably has a transverse channel 13 and longitudinal channels 12 intersecting the transverse channel 13. For ease of processing, the two are preferably perpendicularly distributed. Several longitudinal channels 12, transverse channels 13, and air holes 11 located above the channels are interconnected. To ensure uniform suction, the air holes 11 are evenly distributed on the working surface of the upper suction plate 1. At least one end of one of the transverse or longitudinal channels is provided with a fixing hole 14, into which the air pipe of the vacuum system is installed to draw air from or cut off the air supply to the upper suction plate 1. To facilitate the adsorption of the cloth 100, a felt is installed on the surface of the upper suction plate 1.

[0029] To facilitate manual assisted flipping, a handle 111 can be provided on the opposite side of the working surface of the upper suction plate 1.

[0030] The lower support plate 3 is detachably mounted on the support plate 5. Positioning holes are provided at both ends of the lower support plate 3, and corresponding positioning pins can be provided on the support plate 5. The positioning holes can be set as elongated holes along the length direction of the lower support plate 3 to accurately position the width direction of the lower support plate, which facilitates the accurate positioning of the adhesive tape. The length direction can be slightly moved to facilitate the placement of the lower support plate 3 onto the connecting plate 45.

[0031] A centerline 31 is set on the lower support plate 3 along the length direction, and two upper suction plates 1 are set on the left and right sides along the centerline 31, preferably symmetrically arranged on the left and right sides, with the centerline 31 consistent with the edges of the left and right upper suction plates 1.

[0032] like Figure 6 As shown, Figure 6 Figures 6a to 6d are schematic diagrams of the equipment operation during the splicing process of fabric 100. The splicing method or steps for tubular fabric are as follows:

[0033] First, the upper suction plate 1 is flipped open to both sides. To prevent the sheet fabric 100 from falling, the middle part of the fabric is placed on the support plate for support. The two ends of the sheet fabric 100 are aligned with the edges of the upper suction plate 1, so that it is adsorbed onto the upper suction plate 1.

[0034] Next, place the lower support plate 3 onto both ends of the support plate 5 for positioning. Before placing the lower support plate 3, fix the adhesive tape 15 at the center line position, with the adhesive tape 15 facing upwards and fixed on the lower support plate 3.

[0035] Then, the upper suction plate 1 flips inward. At this time, the upper suction plate 1, the lower support plate 3, and the support plate 5 are parallel to each other and close to each other. The leveling mechanism lifts the lower support plate 3 and moves it to the upper suction plate 1, pressing the adhesive surface of the adhesive tape 15 onto the fabric 100. The two ends of the fabric are firmly bonded by the adhesive tape. Since the adhesive tape is fixed along the centerline of the lower support plate 3, and the upper suction plate 1 is symmetrically arranged along the centerline of the lower support plate 3, the adhesive tape 15 is basically located in the middle of the end after being pasted.

[0036] Finally, the upper suction plate 1 is de-aired, flipped outward, and the lower support plate 3 is picked up or removed to take out the tubular cloth 100.

[0037] The mounting mechanism 4 returns to its original position, awaiting the next assembly.

[0038] 100 tubular fabrics Figure 2 As shown, the two end joints are secured internally with adhesive tape 15. Then, the process moves to the next station for winding the rope and adhesive.

[0039] In the winding process, the spliced ​​tubular fabric is first placed onto the forming hub, with the adhesive tape facing the surface of the forming hub and the unadhesive tape facing away from the surface of the forming hub, and then wound to form a rubber strip blank. The rubber strip blank surrounds the outer circumference of the forming hub and includes the tubular fabric 204' forming the back fabric of the multi-wedge belt, the top rubber 203' outside the tubular fabric 204', the cord 202 outside the top rubber 203', and the bottom rubber 201' outside the cord 202. For some multi-wedge belts, a wedge fabric can be provided on the bottom rubber, such as a weft-knitted fabric with good circumferential extension in the mold direction.

[0040] The rubber strip blank is demolded, and the rubber strip blank on the molding hub is separated from the molding hub to form a cylindrical strip blank 200', which is then transferred to the process of tearing the adhesive tape.

[0041] In the process of tearing off the adhesive tape, after the rubber strip blank is demolded, since the adhesive tape is located inside the cylindrical strip blank at 200°, it is easy to tear off the adhesive tape 15 at the end of the connecting fabric from the inside. Figure 7 Given that the winding process applies a certain amount of pressure, the fabric and the adhesive rubber layer will develop a certain degree of adhesion after being wound with the cord. Therefore, the fabric retains its original seamless connection after the adhesive tape is removed.

[0042] In the vulcanization process, the cylindrical strip is placed between the outer and inner molds of the vulcanization mold. There is a certain gap between the outer and inner molds, and the strip is placed into this gap. Figure 8 The inner mold includes a mandrel 301 and an air bladder 302 fitted onto the outer surface of the mandrel 301. The inner surface of the outer mold 400 has ribs extending in a circumferential direction. Under high pressure, any suitable temperature-controlled fluid medium, such as steam, is supplied, causing the air bladder 302 to expand radially outward, compressing the cylindrical strip blank to expand radially outward, forcing the base rubber into the spaces between the ribs on the inner surface of the outer mold 400. The air bladder 302 is generally a cylindrical structure formed by rubber vulcanization. During this process, the fabric, top rubber, cord, and base rubber inside the cylindrical strip blank form a single integrated structure, while wedges are formed on the base rubber in a multi-wedge strip.

[0043] Cutting and shaping: Take the vulcanized strip cylinder out of the vulcanization mold and place it on the cutting machine to cut it into the required number of wedges to form a multi-wedge strip.

[0044] Production testing confirmed that no cracks occurred during fabric splicing, and the adhesive tape ensured the continuity of the production process. The fabrics fused together well during vulcanization. After vulcanization, the splicing marks were virtually invisible on the surface of the belt, and the overlaps were smooth, meeting production requirements.

[0045] This method of processing multi-ribbed tape has fully met the performance requirements after durability testing, and the fabric splicing points did not crack after passing the durability test, thus satisfying the performance requirements of multi-ribbed tape.

[0046] Therefore, multi-wedge tape produced in this way can be mass-produced and can effectively improve the problems encountered in the current stitching overlap method, achieving the effect of optimization and improvement.

Claims

1. A method for producing multi-ribbed belts, characterized in that, First, the sheet fabric is spliced ​​using a multi-wedge tape splicing device. This device includes a support frame, an upper suction plate, a lower support plate, a support plate, and a leveling mechanism. The upper suction plate is rotatably mounted on the upper crossbeam at the top of the support frame. The leveling mechanism is fixedly mounted on the lower crossbeam of the support frame. The support plate is fixedly mounted on the leveling mechanism. The lower support plate is detachably mounted on the support plate. The leveling mechanism and the lower support plate are located on opposite sides of the support plate. The leveling mechanism can move the support plate up and down. The upper suction plate is located above the lower support plate. The upper suction plate is a vacuum suction plate with a working surface. There are two symmetrical upper suction plates. When the two upper suction plates are flipped open to both sides, the two ends of the sheet cloth are aligned with the edges of the upper suction plates, so that it is adsorbed onto the upper suction plates. The two ends of the sheet cloth are seamlessly aligned to form a tube shape. Then, the lower support plate with adhesive tape is placed on the support plate. Then the upper suction plate is flipped inward. The leveling mechanism lifts the lower support plate and moves it to the upper suction plate, pressing the adhesive tape to the end of the cloth. The two ends of the cloth are fixed inside the tube-shaped cloth with adhesive tape to form a tube-shaped cloth. The tubular cloth is placed on the forming hub, and top rubber, rope and bottom rubber are wound around it to form a rubber strip blank; The rubber strip blank is demolded from the forming hub to form a cylindrical strip blank; Remove the adhesive tape from the inside of the cylindrical strip blank; A cylindrical strip blank is placed into the cavity between the outer and inner molds of a vulcanizing mold, and then heated and pressurized to expand and vulcanize, forming a vulcanized strip cylinder. The vulcanized strip is removed and cut into shape to form a multi-wedge strip.

2. The method for producing multi-wedge belts as described in claim 1, characterized in that, The adhesive tape is a cloth-based tape.

3. The method for producing multi-wedge belts as described in claim 1, characterized in that, The inner mold includes a core rod and an air bladder sleeved on the outer surface of the core rod, and the inner surface of the outer mold is provided with ribs extending in the circumferential direction.

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