A method for manufacturing a plastic endless synchronous belt

Abstract

The application provides a method for preparing a plastic endless synchronous belt, comprising the following steps: taking a forming die of a plastic endless synchronous belt mold, sleeving a metal inner core of the synchronous belt into the forming die, and making the metal inner core of the synchronous belt and the forming die concentric, injecting plastic material into the forming die and forming after extrusion, and cooling to obtain a plastic endless synchronous belt mold body after setting; processing one or two parallel thread core grooves by using a numerical control lathe, winding a wire core in the thread core groove for fixing; placing the plastic endless synchronous belt mold body with the processed wire core into an outer mold of the synchronous belt, injecting synchronous belt material, and then performing vulcanization treatment; removing the outer mold of the synchronous belt, cooling the plastic endless synchronous belt mold and the endless synchronous belt together, fixing to a slitting machine after complete cooling, and cutting to obtain the endless synchronous belt, and the synchronous belt circumference precision is ensured by cold mold demolding.

Description

Technical Field

[0001] This invention relates to the field of mechanical transmission components, and in particular to a method for preparing a plastic annular synchronous belt. Background Technology

[0002] Currently, the production of annular synchronous belt molds widely utilizes metal materials. Metalworking synchronous belt molds require equipment such as cutting machines, CNC lathes, gear hobbing machines, internal grinding machines, external cylindrical grinding machines, and deburring machines. This involves numerous processes and multiple station transitions, resulting in repeated installation and disassembly of the product. The direct negative impact is the influencing of errors and the potential damage to the product during installation and disassembly. Furthermore, the process is complex, labor-intensive, and inefficient. Moreover, during production, such as machining on CNC lathes, coolants like cutting fluid or cutting oil are used to cool the product, or surface treatments with chemicals like nitric acid are applied, leading to resource waste, environmental pollution, and increased production costs. Additionally, current vulcanization technology requires at least one hour.

[0003] In existing technologies, to improve production efficiency and reduce the difficulty of demolding annular synchronous belts, high-temperature demolding is used during the production process. The demolding temperature can reach 80℃-150℃. This directly leads to uneven shrinkage after demolding, causing the tooth shape and length of the annular synchronous belt to fail to meet accuracy requirements. Furthermore, existing annular synchronous belt molds lack threaded core grooves, making it impossible to ensure uniform distribution of the core during winding. Even with skilled operators who can ensure uniform winding, slippage can occur during the injection of synchronous belt material, resulting in uneven core distribution and compromised quality. Moreover, the current method of producing synchronous belts involves demolding the annular synchronous belt and then cutting it to meet user standards. This double-positioning cutting introduces errors, resulting in inconsistent and significant dimensional inconsistencies in the annular synchronous belt.

[0004] In summary, the technical problem actually solved by this invention is how to ensure the circumference accuracy of the synchronous belt through cold mold demolding, ensure the width accuracy of the synchronous belt by cutting when the mold and the synchronous belt are not demolded, and ensure the uniformity of the wire core by using wire core grooves, thus ensuring the production quality of the synchronous belt. Summary of the Invention

[0005] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a method for preparing a plastic annular synchronous belt, which ensures the accuracy of the synchronous belt circumference and width, as well as the uniformity of the synchronous belt core.

[0006] This invention discloses a method for preparing a plastic annular synchronous belt, comprising the following steps:

[0007] Take the molding die of the plastic annular synchronous belt mold, and place the metal inner core of the synchronous belt inside the molding die, ensuring that the metal inner core and the molding die are concentric. Inject plastic material into the molding die and extrude it. After cooling to set, the main body of the plastic annular synchronous belt mold is obtained. Take the main body of the plastic annular synchronous belt mold and machine threaded core grooves (one or two parallel grooves) using a CNC lathe. The core of the synchronous belt is then wound and fixed within the threaded core grooves. Take the main body of the plastic annular synchronous belt mold with the machined threaded core grooves, place it in the outer mold of the synchronous belt, inject the synchronous belt material, and perform vulcanization treatment. After removing the outer mold of the synchronous belt, cool the main body of the plastic annular synchronous belt mold with the synchronous belt. After cooling, fix it to a slitting machine and cut it to obtain the annular synchronous belt. The method for machining the threaded core grooves is as follows: fix the cooled plastic annular synchronous belt mold body on a CNC lathe by internal expansion, and rotate the tool post angle of the CNC lathe to machine at least one parallel threaded core groove. After machining the threaded core groove, the tooth runout is tested and is less than 0.03mm. However, due to the different synchronous belt products to be prepared, the depth of the threaded core groove is 0.05mm-3mm and the spacing of the threaded core groove is 0.05mm-3mm.

[0008] Preferably, a winding machine with adjustable core tension is used to evenly wind the core along the threaded core groove.

[0009] Preferably, depending on the synchronous belt product to be prepared, the winding tension of the winding machine is 3N-500N, and the diameter of the winding core is 0.05mm-3mm.

[0010] Preferably, due to the different materials used to prepare the synchronous belt, some materials require the first winding of an elastic cloth before winding the core wire, and the thickness of the elastic cloth varies from 0.1mm to 2mm depending on the specifications of the synchronous belt.

[0011] Preferably, the size of the plastic annular synchronous belt mold body and the transmission belt is greater than 0.01mm-0.5mm.

[0012] Preferably, when injecting the material, the material is injected into the molding die at an injection pressure of 6MPa-12MPa and an injection temperature of 190℃-260℃, and after initial cooling for 10s-60s, it is extruded and then fully cooled a second time for no less than 24 hours.

[0013] Preferably, the injection method of the molding die for the plastic annular synchronous belt is multi-point injection.

[0014] Preferably, the vulcanization temperature during vulcanization is 50-200℃, and the vulcanization time is 0.5h-24h.

[0015] Preferably, the material of the timing belt outer mold includes: metal, rubber, plastic, etc.

[0016] Preferably, depending on the scenario, the inner wall of the synchronous belt outer mold can be a smooth inner wall, a toothed inner wall, or one or more inner walls, etc.

[0017] Compared with the prior art, the beneficial effects of this invention, achieved by adopting the above technical solution, are as follows: The synchronous belt is cut simultaneously with a plastic synchronous belt mold after complete cooling, and then the synchronous belt is generated according to the cut mold. The synchronous belt is obtained after complete cooling, ensuring the accuracy of the synchronous belt's circumference and reducing the error in the width of the annular synchronous belt caused by secondary installation and cutting. Furthermore, because it is cut simultaneously with the plastic synchronous belt mold, uneven cutting and bending of the annular synchronous belt are reduced. The cut plastic material can also be recycled and reused, thus saving costs. By setting threaded core grooves to fix the synchronous belt's core, the uniformity of the core distribution is ensured, improving the quality of the synchronous belt. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a method for preparing a plastic annular synchronous belt mold according to the present invention;

[0019] Figure 2 This is a schematic diagram of the main body of the plastic annular synchronous belt mold of the present invention (after winding the core wire);

[0020] Figure 3 This is a schematic diagram of a synchronous belt prepared using the mold of the present invention;

[0021] Figure 4 This is a schematic diagram of the outer mold with a smooth inner wall for the synchronous belt of the present invention;

[0022] Figure 5 This is a schematic diagram of the shape of the metal core in this invention. Detailed Implementation

[0023] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0025] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0026] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0027] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0029] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0030] See Figure 1 and Figure 5As shown, this embodiment provides a method for preparing a plastic annular synchronous belt mold, including the following steps: first, take the molding die of the plastic annular synchronous belt mold, then place the metal inner core of the synchronous belt inside the molding die, and make the metal inner core of the synchronous belt and the molding die concentric, that is, make the axis of the metal synchronous belt and the axis of the molding die unified, so as to ensure that the concentricity of the outer diameter and the inner diameter of the prepared plastic annular synchronous belt mold is consistent. After the metal inner core of the synchronous belt and the molding die are concentric, the material is injected into the molding die by multi-point injection method with an injection pressure of 6MPa-12MPa and an injection temperature of 190℃-260℃. After the injection, after a preliminary cooling of 10s-60s, the material is extruded and molded by applying pressure to ensure the product accuracy. After extrusion molding, the material is cooled a second time. After the second cooling, the main body of the plastic annular synchronous belt mold is obtained.

[0031] like Figure 2 As shown, after two rounds of thorough cooling, a plastic annular synchronous belt mold body is obtained. At least one parallel threaded core groove is machined into the mold body. The purpose of this threaded core groove is to allow the synchronous belt core to be wound into the groove, preventing slippage during use and ensuring even distribution of the core, which would negatively impact the quality of the synchronous belt. After machining the threaded core groove, the core is wound into it and fixed in place.

[0032] Take the plastic annular synchronous belt mold body with the threaded core groove processed and the core fixed in the threaded core groove, place it in the synchronous belt outer mold and inject synchronous belt material, and then perform vulcanization treatment. After vulcanization treatment, the plastic annular synchronous belt mold, the synchronous belt outer mold and the synchronous belt form an integral body.

[0033] The plastic synchronous belt mold, the outer mold of the synchronous belt, and the main body formed by the synchronous belt after vulcanization are taken. The outer mold of the synchronous belt is removed, and the main body of the plastic annular synchronous belt mold with the synchronous belt is cooled. After cooling, it is fixed to the slitting machine and then cut to obtain the plastic annular synchronous belt mold.

[0034] It should be noted that, depending on the material of the timing belt, the core material includes, but is not limited to, galvanized steel wire, copper-plated steel wire, aramid wire, nylon wire, stainless steel wire, carbon fiber wire, glass fiber, silk wire, etc.; the material of the timing belt outer mold includes, but is not limited to, metal outer mold, plastic outer mold, rubber ring outer mold, etc.; depending on the application scenario, the inner wall of the timing belt outer mold includes: smooth inner wall, toothed inner wall, one or more grooved inner walls, etc.; the timing belt material includes, but is not limited to, various rubbers, polyurethane, plastics, etc.

[0035] It should be noted that during the second cooling process, the cooling time is no less than 24 hours, so as to ensure that the obtained plastic annular synchronous belt mold body is completely cooled to a fixed shape, and its strength is greatly improved after the second cooling.

[0036] Based on the above steps, the method for machining threaded core grooves can be as follows: the plastic annular synchronous belt mold body prepared by the molding die is fixed on a CNC lathe by internal expansion, and then the tool post angle is rotated according to the core specifications of the corresponding synchronous belt to machine the threaded core grooves in the form of threaded grooves.

[0037] It should be noted that the specific operation involves fixing the plastic annular synchronous belt mold onto the spindle of the CNC lathe through internal expansion, and adjusting the tool post angle according to the wire core specifications to control the depth and angle of the threaded wire core groove. After adjusting the tool post angle, the CNC lathe is started, and the spindle of the CNC lathe begins to rotate, while the tool post performs the feed motion. The main motion of the spindle rotation and the feed motion of the tool post form the threaded wire core groove.

[0038] It should be noted that the wire core specification is between 0.05MM and 3MM.

[0039] According to the above steps, after machining the thread core groove on a CNC lathe, the tooth profile runout needs to be less than 0.03mm. The depth of the thread core groove is 0.05mm-3mm, and the spacing of the thread core groove is 0.05mm-3mm.

[0040] It should be noted that different thread core groove depths and spacings will be selected for the synchronous belt standard to be prepared according to the requirements. The depth range is 0.05mm-3mm and the spacing is 0.05mm-3mm. However, the synchronous belt standard will be different, but the tooth runout must be less than 0.03mm.

[0041] According to the above steps, when winding the core, the core is evenly wound along the threaded core groove by a winding machine with adjustable core tension, thereby ensuring the quality of the synchronous belt.

[0042] It should be noted that, depending on the required standard of the synchronous belt, the winding tension of the winding machine should be selected as 3N-500N, and the diameter of the winding core should be selected as 0.05mm-3mm.

[0043] According to the above steps, since the synchronous belt products are different, as mentioned above, the synchronous belt materials include, but are not limited to, various rubbers, polyurethanes, plastics, etc. Therefore, when using some materials to prepare synchronous belts, it is necessary to first wrap the elastic cloth and then wrap the wire core. The thickness of the elastic cloth is 0.1mm-2mm, and when the wire core is wrapped after the elastic cloth is wrapped, the winding tension is 3N-500N.

[0044] It should be noted that the materials of timing belts also include, but are not limited to, rubber, polyurethane, and plastic;

[0045] Based on the above steps, the size of the main body of the plastic synchronous belt pulley molding die is 0.01mm-0.5mm larger than the size of the synchronous belt.

[0046] It should be noted that during vulcanization, the vulcanization temperature ranges from 50℃ to 200℃, and the vulcanization time ranges from 0.5h to 24h, depending on the material of the synchronous belt.

[0047] In summary, before cutting, the timing belt and the plastic mold are not yet separated. Cutting is then performed directly to ensure the correct timing belt width. The old method involved demolding first, then installing the belt onto a cutting machine. However, this method had two drawbacks: 1) the secondary installation could not guarantee concentricity, and 2) the timing belt is flexible and would bend after installation, resulting in a bent belt after cutting.

[0048] Based on the above steps, it can be seen that after cutting the main body of the plastic annular timing belt mold with timing belt, the metal inner core can be removed for repeated use. Furthermore, after cutting the main body of the plastic annular timing belt mold with timing belt, the cut-off part can be crushed and recycled, thereby reducing costs.

[0049] See Figures 2-4 As shown, the method of the present invention involves concentrically setting the molding die of the plastic annular synchronous belt mold with the metal inner core, injecting plastic material into the mold, and then extruding it to obtain the desired product. Figure 2 The plastic annular timing belt mold shown is then used to make... Figure 4 The timing belt outer mold shown is placed on a plastic annular timing belt mold, then the timing belt material is injected and vulcanized to obtain the desired result. Figure 3 The synchronous belt shown.

[0050] It should be noted that the specific shape of the timing belt is determined by the plastic annular timing belt mold and the outer mold of the timing belt. Figure 3 It can be inferred that the tooth profile of the timing belt can also be on the outer ring of the timing belt, and the outer ring can also include 1 to N regular or irregular stops or protrusions (determined by the outer mold).

[0051] Referring to the above embodiments, another implementation of the method for preparing a plastic annular synchronous belt mold is as follows: The metal core of the synchronous belt is placed inside the molding die, ensuring concentricity between the metal core and the mold. Plastic powder is then injected into the mold using a multi-point injection method. The mold is then extruded using a press, and cooled for 10-60 seconds to complete the final product. The purpose of extrusion is to expel air from the injected plastic powder, resulting in a tighter contact between the powder particles and thus improving the quality of the final product.

[0052] It should be noted that during the extrusion process after injecting plastic powder, the injected plastic powder is directly pressed into shape. The difference from the above embodiment is that the extrusion method in the above embodiment involves an injection molding machine extruding a synchronous belt, while this embodiment uses a press to extrude the plastic powder into shape.

[0053] It should be noted that, in order to prevent the plastic annular synchronous belt mold body from sticking to the synchronous belt when implementing this embodiment, before the wire core is evenly wound along the threaded wire core groove by the winding machine with adjustable wire core tension, release oil and / or heat insulation material are sprayed on the plastic annular synchronous belt mold body. The release oil and heat insulation material are used to isolate the plastic annular synchronous belt mold body and the synchronous belt, so that the plastic annular synchronous belt mold body and the synchronous belt will not stick to each other due to heat conduction.

[0054] Smart terminals can be implemented in various forms. For example, the terminals described in this invention may include smart terminals such as mobile phones, smartphones, laptops, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), navigation devices, etc., as well as fixed terminals such as digital TVs, desktop computers, etc. Hereinafter, it is assumed that the terminal is a smart terminal. However, those skilled in the art will understand that, in addition to elements specifically designed for mobile purposes, the construction according to embodiments of the present invention can also be applied to fixed-type terminals.

[0055] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a plastic annular synchronous belt, characterized in that, Including the following steps: Take the molding die of the plastic annular synchronous belt mold, and place the metal inner core of the synchronous belt inside the molding die, making the metal inner core of the synchronous belt and the molding die concentric. Inject plastic material into the molding die and form it by extrusion. After cooling to set, the main body of the plastic annular synchronous belt mold is obtained. Take the main body of the plastic annular synchronous belt mold and machine one or two parallel threaded core grooves using a CNC lathe, and then fix the core of the synchronous belt by winding it into the threaded core grooves; Take the plastic annular synchronous belt mold body after the core wire has been processed, place it in the synchronous belt outer mold, and inject the synchronous belt material before vulcanization treatment; After removing the outer mold of the timing belt, the plastic annular timing belt mold body and the annular timing belt are cooled together. After complete cooling, they are fixed to the slitting machine and cut to obtain the annular timing belt.

2. The method according to claim 1, characterized in that, Use a winding machine with adjustable core tension to evenly wind the core along the threaded core groove.

3. The method according to claim 2, characterized in that, The winding tension of the winding machine is 3N-500N, and the diameter of the winding core is 0.05mm-3mm.

4. The method according to claim 2, characterized in that, Before winding the core, an elastic cloth with a thickness of 0.1mm-2mm is first wound around it.

5. The method according to claim 1, characterized in that, Material is injected into the molding die at an injection pressure of 6MPa-12MPa and an injection temperature of 190℃-260℃. After initial cooling for 10s-60s, it is extruded and then fully cooled for a second time of no less than 24 hours.

6. The method according to claim 1, characterized in that, The molding die for the plastic annular synchronous belt uses a multi-point injection method for material injection.

7. The method according to claim 1, characterized in that, The vulcanization temperature for the vulcanization treatment is 50-200℃, and the vulcanization time is 0.5h-24h.

8. The method according to claim 1, characterized in that, The materials of the outer mold of the synchronous belt include: metal, rubber, and plastic.

9. The method according to claim 1, characterized in that, Depending on the application scenario, the inner wall of the outer mold of the synchronous belt includes: a smooth inner wall, a toothed inner wall, or one or more grooved inner walls.

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