Molds for chain conveyor devices and rollers used in manufacturing chain conveyor devices

Abstract

This invention relates to a chain conveyor device and a mold for manufacturing rollers for the chain conveyor device. The roller of this invention comprises a straight cylindrical body with an outer peripheral wall and an inner peripheral wall. Multiple straight reinforcing ribs are arranged between the outer and inner peripheral walls. Both ends of each reinforcing rib are connected to the inner side of the outer peripheral wall. Each reinforcing rib is axially symmetrical with another reinforcing rib about the diameter of the circular cross-section of the body, forming an A-type load-bearing structure. The roller for the chain conveyor device according to this invention has a structure with optimized design of key parameters such as the number, angle, arrangement, and size of the reinforcing ribs. Furthermore, it utilizes a composite material containing fiber reinforcement with a "skeleton structure," significantly improving radial load-bearing capacity.

Description

Technical Field

[0001] This invention relates to a chain conveyor and a mold for manufacturing rollers for the chain conveyor. Background Technology

[0002] This section provides background information relevant to this application, which does not necessarily constitute prior art.

[0003] In industrial production processes such as beverage bottling, agricultural harvesting, cement conveying, and latex impregnation, chain conveyors are frequently used to transport products between different workstations. In these applications, chains operate at slow speeds but bear heavy loads, and the total length and number of links of the chains used are considerable, resulting in chains that typically weigh tens of tons. Excessive chain mass significantly increases the tension on the chain, thus increasing wasted power. This problem is particularly pronounced for conveyor chains with large rollers, where the rollers account for a large proportion of the chain's mass (approximately 40%). Therefore, reducing the weight of the conveyor chain itself is a crucial aspect of conveyor chain design.

[0004] To reduce the weight of conveyor chains, existing technologies utilize engineering plastics to manufacture rollers. Using engineering plastics reduces roller weight, thereby improving the motor efficiency of the conveyor chain. For example, in latex / nitrile rubber glove conveyor lines requiring repeated heating / cooling, lightweight rollers reduce additional heating energy consumption. Furthermore, engineering plastic rollers offer advantages such as reduced friction, lower noise (improving the workshop environment), and no need for grease lubrication (maintenance-free). However, conventional engineering plastic rollers have relatively low strength, limiting their use to small conveyor chains or rollers on lighter conveyor chain accessories. Furthermore, manufacturing large rollers using injection molding with engineering plastics presents the challenge of producing solid rollers, necessitating the use of a technique known in the art as "hollowing out" to create hollow sections within the roller. While this facilitates injection molding and further reduces weight, it negatively impacts the roller's strength and load-bearing capacity. Summary of the Invention

[0005] The purpose of this invention is to solve one or more of the technical problems mentioned above. In particular, the purpose of this invention is to develop an engineering plastic roller that has significantly improved strength and load-bearing capacity compared to traditional engineering plastic rollers, and whose performance is comparable to that of steel rollers.

[0006] According to one aspect of the present invention, a roller for a chain conveyor is provided. The roller includes a body in the shape of a straight cylinder, the body having an outer peripheral wall and an inner peripheral wall, and a plurality of straight reinforcing ribs are provided between the outer peripheral wall and the inner peripheral wall. Both ends of each reinforcing rib are connected to the inner side of the outer peripheral wall, and each reinforcing rib is axially symmetrical with another reinforcing rib about the diameter of the circular cross-section of the body and forms an A-type load-bearing structure.

[0007] According to one aspect of the invention, the number of reinforcing ribs is an odd prime number.

[0008] According to one aspect of the invention, the number of reinforcing ribs is 11, 17, or 19.

[0009] According to one aspect of the invention, the number of reinforcing ribs is 19.

[0010] According to one aspect of the invention, each reinforcing rib is tangent to the inner peripheral wall.

[0011] According to one aspect of the invention, a plurality of reinforcing ribs are evenly spaced between the outer peripheral wall and the inner peripheral wall.

[0012] According to one aspect of the invention, the wall thickness of the reinforcing rib is uniform.

[0013] According to one aspect of the invention, the wall thickness of the reinforcing rib is 2 mm to 4 mm.

[0014] According to one aspect of the present invention, a plurality of reinforcing ribs intersect to form a mesh structure, and a plurality of non-penetrating mesh holes of varying density are formed between each reinforcing rib, the non-penetrating mesh holes having the same depth.

[0015] According to one aspect of the invention, the roller is made of a composite material comprising fiber-reinforced material.

[0016] According to one aspect of the invention, the substrate of the composite material is polyamide.

[0017] According to one aspect of the present invention, the substrate of the composite material is an aromatic polyamide.

[0018] According to one aspect of the invention, the fiber-reinforced material comprises glass fiber or carbon fiber.

[0019] According to one aspect of the invention, the average length of the glass fiber is 6 mm to 12 mm.

[0020] According to one aspect of the invention, the average length of the glass fiber is 11 mm.

[0021] According to one aspect of the invention, the glass fiber content is greater than 50%.

[0022] According to one aspect of the invention, the glass fiber content is 60%.

[0023] According to another aspect of the present invention, a mold for manufacturing the aforementioned roller is provided, the mold comprising a moving mold and a fixed mold, having a cavity for forming the roller between the moving mold and the fixed mold, and having a gate in the middle of the cavity, the gate being disc-shaped.

[0024] In summary, the rollers for chain conveyor devices according to the present invention offer the following beneficial technical effects: weight reduction of more than 75% compared to conventional large steel rollers, reduced heating energy consumption, reduced friction, reduced noise, and no need for grease lubrication. The strength and load-bearing capacity of the rollers of the present invention are significantly improved compared to traditional engineering plastic rollers, and their performance is comparable to that of steel rollers. Attached Figure Description

[0025] The foregoing and other features and characteristics of this application will become clearer from the following detailed description with reference to the accompanying drawings, which are merely illustrative and not necessarily drawn to scale. The same reference numerals are used in the drawings to indicate the same parts, in which:

[0026] Figure 1 A top view showing the rollers operating in the straight section of the chain conveyor;

[0027] Figure 2 A side view showing the rollers operating in the curved section of the chain conveyor;

[0028] Figure 3 This is a perspective view of a roller according to an embodiment of the present invention;

[0029] Figure 4 This is a top view of a roller according to an embodiment of the present invention;

[0030] Figure 5 A cross-sectional view of a roller according to an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of a roller under pressure according to an embodiment of the present invention;

[0032] Figure 7 This is a perspective view of the moving mold portion of the mold for a roller according to an embodiment of the present invention;

[0033] Figure 8 This is a perspective view of the fixed mold portion of the mold for a roller according to an embodiment of the present invention;

[0034] Figure 9 This is a side cross-sectional view of the roller according to an embodiment of the present invention during injection molding in a mold;

[0035] Figure 10This is a side cross-sectional view of the roller according to an embodiment of the present invention after injection molding;

[0036] Figure 11 This is a side cross-sectional view of the roller according to an embodiment of the present invention after removing the sprue portion;

[0037] Figure 12 A graph showing the stress test results of ordinary short glass fiber reinforced materials;

[0038] Figure 13 The graph shows the test results of the pressure that the composite material containing fiber reinforcement used in this invention can withstand. Detailed Implementation

[0039] Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings. The following description is exemplary in nature and is not intended to limit the invention or its application or use. Rollers made of composite materials containing fiber reinforcement according to the invention can be applied to any desired conveying device.

[0040] Reference Figure 1 In the straight section of the chain conveyor 1, the chain conveyor 1 includes a chain linked together by a plurality of rollers 10. Two adjacent rollers 10 are connected by a connecting shaft 20 passing through a central hole of the roller 10 and connecting plates 22 located at both ends of the roller 10. During operation of the chain conveyor 1, the inner peripheral wall of the central hole of the roller 10 is subjected to pressure applied by the connecting shaft 20. This pressure is generally perpendicular to the direction of travel of the chain conveyor 1 and also generally perpendicular to the plane in which the roller 10 rolls. (Refer to...) Figure 2 In a turning section of a chain conveyor 1, the chain moves under the action of the drive gear 30 of the chain conveyor 1, and the outer peripheral wall of the roller 10 is subjected to pressure exerted by the tooth root of the gear tooth 301. In the above two working conditions, the design goal of the roller 10 is to expect the roller 10 to withstand pressures exceeding 30kN or even exceeding 35kN.

[0041] As mentioned above, to reduce the weight of the rollers, engineering plastics are used to manufacture them using injection molding. However, the wall thickness of products manufactured using injection molding should not be too large, otherwise defects will occur in the product. Therefore, large rollers cannot be made into solid bodies. For this reason, multiple reinforcing ribs are usually designed between the inner and outer peripheral walls of the rollers made of engineering plastics, and it is necessary to ensure that the wall thickness of the reinforcing ribs is appropriate.

[0042] See Figures 3 to 5The roller 10 of the chain conveyor 1 of the present invention includes a straight cylindrical body having an outer peripheral wall 12 and an inner peripheral wall 14. A plurality of straight reinforcing ribs 16 are provided between the outer peripheral wall 12 and the inner peripheral wall 14, thereby forming a plurality of mesh holes 17 at the two end faces between the outer peripheral wall 12 and the inner peripheral wall 14. Both ends of each reinforcing rib 16 are connected to the inner side of the outer peripheral wall 12. For example, in... Figure 4 Two reinforcing ribs 16 are shown, connecting to the inner side of the outer peripheral wall 12 at points A, B, D, and E, respectively. The middle portion of the reinforcing rib 16 is tangent to the inner peripheral wall 14. For example, as shown... Figure 4 As shown in the figure, the reinforcing ribs 16 indicated by dashed line segment AB and 16 indicated by dashed line segment DE are tangent to the dashed circle O, centered at O, between the outer circumferential surface and the cylindrical inner circumferential surface of the inner peripheral wall 14, at points C and H, respectively. As shown, both the reinforcing ribs 16 and the inner peripheral wall 14 have a certain wall thickness. Therefore, the dashed circle O is not necessarily located exactly at the midpoint between the outer and inner circumferential surfaces of the inner peripheral wall 14. The relative positional relationship between the reinforcing ribs 16 and the inner peripheral wall 14 can be adjusted as needed, as long as the reinforcing ribs 16 and the inner peripheral wall 14 overlap at the tangency points C and H, and the reinforcing ribs 16 do not affect the integrity of the cylindrical inner circumferential surface of the inner peripheral wall 14. Multiple reinforcing ribs 16 are evenly distributed between the outer peripheral wall 12 and the inner peripheral wall 14, such that the diameter of any reinforcing rib 16 (AB) and another reinforcing rib 16 (DE) about the circular cross-section of the body (e.g., in...) Figure 4 (Shown by dashed line segment EF) It is axially symmetrical and forms a series of A-type load-bearing structures.

[0043] See Figure 6 When the outer peripheral wall 12 of the roller 10 is subjected to pressure F, the pressure F is normally oriented to the surface of the outer peripheral wall 12, thus pointing towards the center O of the circular cross-section of the roller 10. As a result, the pressure F is transmitted to other parts of the roller 10 at least through the aforementioned type A load-bearing structure, thereby effectively dispersing the internal stress of the roller 10.

[0044] By combining theoretical design (e.g., finite element analysis) and experimental methods, the inventors determined that the number of reinforcing ribs 16 should be an odd prime number. In this invention, the number of reinforcing ribs 16 is 11, 17, or 19. Preferably, the number of reinforcing ribs 16 is 19. Determining the number of reinforcing ribs 16 as an odd prime number is to avoid the forces acting on the reinforcing ribs 16 canceling each other out when the number of reinforcing ribs 16 is set to an even number, making it difficult to distribute the forces throughout the roller 10.

[0045] Specifically, multiple reinforcing ribs 16 are evenly spaced between the outer peripheral wall 12 and the inner peripheral wall 14 around the axis of the roller 10, thereby achieving the purpose of evenly distributing the force. In this case, when the number of reinforcing ribs 16 is determined, the angle between each reinforcing rib 16 is also determined.

[0046] As described above, the wall thickness of the reinforcing rib 16 is uniform for injection molding process considerations. In this invention, the thickness of the reinforcing rib 16 is 2 mm to 4 mm. This wall thickness is beneficial for injection molding and avoids defects in the roller 10.

[0047] As described above, multiple reinforcing ribs 16 intersect to form a mesh-like structure. Several non-penetrating mesh holes 17 of varying density are formed between each reinforcing rib 16. See also... Figure 5 The non-penetrating mesh holes 17 have the same depth, resulting in a more uniform wall thickness in the injection-molded product. Additionally, as... Figure 5 As shown, the mesh holes are formed to taper along the depth direction, which facilitates demolding.

[0048] The advantages of the above structural design are as follows: by optimizing key parameters such as the number, angle, arrangement, and size of the reinforcing ribs 16, when the roller 10 is subjected to pressure, the pressure is distributed to the whole roller 10, thereby dispersing the large stress on the local outer surface of the roller 10 into multiple smaller stresses inside the roller 10, so that the roller 10 can withstand greater pressure or energy. This achieves improved roller strength, overall pressure resistance, reduced vibration, reduced wear, and stress dispersion. It also facilitates injection molding and further reduces weight.

[0049] In addition to the above-described structural design of the roller 10, the present invention also selects a material for the roller 10. Specifically, the roller 10 of the present invention is made of a composite material containing fiber-reinforced material. In particular, in the present invention, the fiber-reinforced material includes glass fiber. However, those skilled in the art will understand that the fiber-reinforced material is not limited to glass fiber, but may include carbon fiber or other fiber-reinforced materials.

[0050] In this invention, the base material of the composite material is polyamide. Polyamide possesses excellent comprehensive properties, including mechanical properties, heat resistance, wear resistance, chemical resistance, and self-lubricating properties. It also has a low coefficient of friction, is easy to process, and is suitable for reinforcement and modification with fiber-reinforced materials and other fillers to improve performance and expand its application range. Therefore, polyamide is widely used in industries such as machinery, chemicals, instrumentation, and automobiles to replace metals such as copper in the manufacture of bearings, gears, pump impellers, and other parts. Preferably, the base material of the composite material is aromatic polyamide. Aromatic polyamide has advantages such as high strength, good toughness, high temperature resistance, low moisture absorption, ease of processing and molding, and greater dimensional stability.

[0051] In particular, the composite material containing fiber reinforcement of the present invention has a "skeleton structure." That is, fiber reinforcement is added to the matrix of the composite material, so that the fiber reinforcement forms the "skeleton" of the matrix. The inventors conducted a 500°C ash content test on the roller 10 of the present invention, a test well known in the art. After this test, the remaining fiber reinforcement material still largely maintained the above-mentioned mesh structure of the roller 10 after calcination. This is different from ordinary short glass fiber reinforcement. Ordinary short glass fiber reinforcement is basically calcined into ash after a similar ash content test, and it is difficult to retain the "skeleton" shape. Therefore, the composite material containing fiber reinforcement of the present invention can better improve the strength of the roller 10.

[0052] Specifically, in the composite material of the present invention, the average length of the glass fibers is 6 mm to 12 mm. Preferably, the average length of the glass fibers is 11 mm.

[0053] Specifically, in the composite material of the present invention, the content of glass fiber is greater than 50%. Preferably, the content of glass fiber is 60%.

[0054] Furthermore, the inventors compared rollers made of ordinary short glass fiber reinforced materials with rollers made of composite materials containing fiber reinforcement materials used in this invention by applying pressure to the outside of the roller.

[0055] See Figure 12 Ordinary short glass fiber reinforced materials can withstand a pressure of around 20kN.

[0056] For comparison, see Table 1 below and Figure 13 The composite material containing fiber reinforcement used in this invention can withstand pressures of >30kN, or even greater than 35kN.

[0057]

[0058] Table 1

[0059] Furthermore, during the injection molding process, "notches" may form at the corners or protrusions of the mold, or during the use of the injection-molded product, "notches" may form on the product itself. These "notches" can adversely affect the product's strength and / or service life. The product's ability to withstand such adverse effects is referred to in the art as the "notch impact effect / notch sensitivity effect." The composite material containing fiber reinforcement of the present invention exhibits excellent "notch impact effect / notch sensitivity effect," thus better ensuring the strength and service life of the roller 10 during injection molding and in actual operation.

[0060] In addition to enhancing the strength and radial load-bearing capacity of the roller 10 in terms of structure and materials as mentioned above, since the roller 10 has the above-mentioned grid structure, in addition to ensuring the uniformity of wall thickness at the reinforcing ribs 16, it is also necessary to consider improving the manufacturing process to better enhance the strength of the roller 10.

[0061] Figures 7 to 11 A mold for injection molding a roller according to an embodiment of the present invention is shown, and in particular, the gate design is shown. (Refer to...) Figure 7 and Figure 8 The mold used to manufacture the roller 10 of the present invention includes a moving mold 40 and a fixed mold 50. For example... Figure 9 As shown, there is a cavity between the moving mold 40 and the fixed mold 50 for forming the roller 10 by injection molding.

[0062] Figure 10 The injection molded part after removing the moving mold 40 and the fixed mold 50 is shown. The roller 10 also has a gate portion 18 corresponding to the gate and a runner portion 19 corresponding to the runner. Figure 11 The figure further illustrates the injection-molded part after the sprue portion 19 has been removed. As shown, the gate portion 18 is disc-shaped and located in the center of the roller 10 (cavity). The gate portion 18 is connected to the inner peripheral wall 14 of the roller 10, so that the injection molding material is uniformly and gradually injected from the inner peripheral wall 14 outward along the radial direction of the roller 10 until it reaches the outer peripheral wall 12.

[0063] The above-mentioned gate design ensures the uniform filling of injection molding material, and minimizes the formation of weld lines caused by trapped air due to the encounter of injection molding materials during injection, which hinders the entanglement effect of polymer molecules, thus ensuring the overall structural uniformity and strength of roller 10.

[0064] (1) This invention optimizes the design of key parameters such as the number, angle, arrangement and size of the reinforcing ribs of the roller, and considers that the overall structure of the roller is under pressure on the inner or outer circumferential surface. The reinforcing ribs are designed as an A-type load-bearing structure, so that the roller can better bear the pressure as a whole.

[0065] (2) In addition, the size of the reinforcing rib is designed to maximize the uniformity of wall thickness, thereby avoiding defects in the roller during the injection molding process, and ensuring the consistency of the sample under stress and the accuracy of the test results data during pressure testing.

[0066] (3) Additionally, the selection of composite materials containing fiber reinforcement with a “skeleton structure” also significantly improves the radial load capacity of the roller.

[0067] (4) In the mold of the present invention, the gate is designed as a disc shape, which ensures that the injection material of the whole product flows evenly and fills in, while avoiding the formation of direct weld lines, and ensuring the uniformity of the overall structural characteristics of the product.

[0068] It should be understood that various different implementation methods can be designed by combining or modifying different implementation methods and various technical features in different ways.

[0069] The foregoing description, in conjunction with specific embodiments, describes a roller for a chain conveyor according to a preferred embodiment of the present invention, and a mold for manufacturing the roller. It is understood that the above description is merely exemplary and not restrictive, and various modifications and variations can be conceived by those skilled in the art with reference to the above description without departing from the scope of the invention. These modifications and variations are also included within the scope of protection of this application.

Claims

1. A chain conveyor device, the chain conveyor device comprising rollers, a chain linked together by a plurality of said rollers, and a drive gear, wherein, Two adjacent rollers are linked by a connecting shaft passing through a central hole in the roller and connecting plates located at both ends of the roller, and the chain moves under the action of the drive gear. The roller is characterized in that it comprises a straight cylindrical body having an outer peripheral wall and an inner peripheral wall, with a plurality of straight reinforcing ribs provided between the outer and inner peripheral walls. Both ends of each reinforcing rib are connected to the inner side of the outer peripheral wall, and each reinforcing rib is axially symmetrical with another reinforcing rib about the diameter of the circular cross-section of the body, forming an A-type load-bearing structure. The roller is made of a composite material containing fiber-reinforced material, and each of the reinforcing ribs is tangent to the inner peripheral wall.

2. The chain conveyor device according to claim 1, characterized in that, The number of the reinforcing ribs is an odd prime number.

3. The chain conveyor device according to claim 2, characterized in that, The number of reinforcing ribs is 11, 17, or 19.

4. The chain conveyor device according to claim 3, characterized in that, The number of reinforcing ribs is 19.

5. The chain conveyor device according to claim 1, characterized in that, The reinforcing ribs are evenly spaced between the outer peripheral wall and the inner peripheral wall.

6. The chain conveyor device according to claim 1, characterized in that, The wall thickness of the reinforcing rib is uniform, ranging from 2 mm to 4 mm.

7. The chain conveyor device according to claim 1, characterized in that, Multiple reinforcing ribs intersect to form a grid-like structure, and several non-penetrating grid holes of varying density are formed between each reinforcing rib, with the non-penetrating grid holes having the same depth.

8. The chain conveyor device according to claim 1, characterized in that, The base material of the composite material is polyamide.

9. The chain conveyor device according to claim 8, characterized in that, The base material of the composite material is aromatic polyamide.

10. The chain conveyor device according to claim 1, characterized in that, The fiber-reinforced material includes glass fiber or carbon fiber.

11. The chain conveyor device according to claim 10, characterized in that, The average length of the glass fiber is 6 mm to 12 mm.

12. The chain conveyor device according to claim 11, characterized in that, The average length of the glass fiber is 11 mm.

13. The chain conveyor device according to claim 10, characterized in that, The glass fiber content is greater than 50%.

14. The chain conveyor device according to claim 13, characterized in that, The glass fiber content is 60%.

15. A mold for manufacturing rollers for a chain conveyor according to any one of claims 1 to 14, characterized in that, The mold includes a moving mold and a fixed mold, with a cavity for forming the roller between the moving mold and the fixed mold, and a gate in the middle of the cavity, the gate being disc-shaped.

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