Machining process of engine belt pulley

Abstract

The invention relates to the field of machining of mechanical parts, in particular to a machining process of an engine belt pulley, which comprises the following steps: S1, blanking: preparing raw materials; s2, stretching: stretching a boss on the raw material prepared in the step S1; s3, shoveling and rotating, wherein the bosses in the step S2 are gathered towards the center to preliminarily form a mandrel; s4, shaping: integrally pressing down the mandrel in the step S3 to enable the mandrel to be consistent up and down; s5, trepanning is carried out, wherein redundant materials on the top of the mandrel in the step S4 are removed, and trepanning is carried out; and S6, spinning is conducted, specifically, after the boss is stretched in the step S2, the left pull-down outer ring becomes the working face where the belt pulley makes contact with the belt. On the premise of ensuring the overall reliability of the product, the machining process is greatly simplified, the machining efficiency is greatly improved, the cost is reduced, and due to the technological characteristic that an inner support is not needed in the shoveling and rotating process, the method is particularly suitable for machining small-size mandrels with the inner diameter smaller than 20 mm.

Description

Technical Field

[0001] The present invention relates to the field of machining of mechanical parts, and particularly to a machining process for an engine pulley. Background Art

[0002] The engine pulley is connected to the main shaft by interference fit through a core shaft and is one of the key components in engine parts. Its machining process directly affects the production efficiency, cost, and the quality and reliability of the final product. Currently, the mainstream machining processes mainly include the welding type and the integral stretching and spinning type, but both of these processes have obvious defects and deficiencies.

[0003] Among them, the welding process is completed by welding the core shaft part and the pulley part into a whole through gas shielded welding. The following main problems exist in the actual application of this process: ① Risk of poor welding: Problems such as incomplete welds, slag residues, and deformation in the heat affected zone may occur during the welding process, resulting in serious failures such as the shaft neck falling off of the pulley part during use. ② Insufficient reliability: Since the welding joint is prone to becoming a stress concentration point, especially under working conditions of high strength and frequent start-stop, the welded joint is more likely to undergo fatigue failure, affecting the service life of the product. ③ Complex post-treatment: The welded parts need to be subjected to additional post-treatment, such as grinding and cleaning, to remove slag and eliminate stress, increasing the production cost and time.

[0004] The integral stretching and spinning process forms the shape of the core shaft through multiple repeated stamping and stretching in the center of a round cake steel plate material, and forms the pulley by spinning the outer edge of the round cake steel plate material. Although the overall reliability of this process is relatively high, the following significant problems still exist: ① Complex process: The forming of the core shaft shape requires more than ten stamping processes. Each process requires precise molds and equipment, and the workpiece transfer and positioning between processes increase the processing difficulty. ② Low efficiency: Multiple stamping processes not only increase the production cycle but also require more equipment and human resources, reducing the overall production efficiency. ③ High cost: Due to factors such as multiple processes, complex molds, and high equipment requirements, the production cost of this process is relatively high, making it difficult to meet the market demand for high cost-effective products.

[0005] With the rapid development of the automotive industry, the market demand for engine pulleys is increasing continuously. Consumers' requirements for products are also getting higher and higher. They not only need to ensure the reliability and service life of the products but also need to reduce the production cost to cope with market competition. The existing processes cannot effectively meet these requirements, and there is an urgent need for a new process with high efficiency, low cost, and high reliability to solve these problems.

[0006] Therefore, those skilled in the art are committed to developing a machining process for engine pulleys with high efficiency, low cost, and high reliability. Summary of the Invention

[0007] In view of the above defects of the prior art, the technical problem to be solved by the present invention is to provide a processing technology for an engine pulley.

[0008] To achieve the above object, the present invention provides a processing technology for an engine pulley, comprising the following steps:

[0009] S1. Blanking: Prepare raw materials;

[0010] S2. Stretching: Stretch out a boss on the raw materials prepared in step S1;

[0011] S3. Shoveling and spinning: Gather the bosses in step S2 towards the center to initially form a mandrel;

[0012] S4. Shaping: Press down the whole mandrel in step S3 to make it consistent up and down;

[0013] S5. Drilling: Remove the redundant materials at the top of the mandrel in step S4 and drill a hole;

[0014] S6. Spinning: Spin the lower outer ring remaining after stretching the boss in step S2 to make it the working surface where the pulley contacts the belt.

[0015] Preferably, in step S1, the raw materials are disc-shaped. The disc-shaped raw materials are convenient for subsequent processing steps.

[0016] Preferably, in step S2, the boss is stretched out by stamping. Stretching out the boss provides material preparation for subsequent shoveling and spinning.

[0017] Preferably, in step S2, the length of the boss is greater than the length of the final mandrel.

[0018] Preferably, the length of the boss is 15 - 20 mm longer than the length of the final mandrel.

[0019] Preferably, in step S3, the shoveling and spinning process is used to gather the bosses towards the center, and the diameter of the gathered bosses is 0.5 - 1 mm smaller than the diameter of the final mandrel.

[0020] Preferably, in step S3, the rotational speed of the shoveling and spinning wheel is 300 - 500 RPM, the blade angle of the shoveling and spinning wheel is 90°, and the inclination angle of the shoveling and spinning wheel is 45°.

[0021] Preferably, in step S4, when pressing down the mandrel, the outer circle of the mandrel is wrapped and its inner wall is supported.

[0022] The beneficial effects of the present invention are as follows: On the premise of ensuring the overall reliability of the product, the present invention greatly simplifies the processing flow, significantly improves the processing efficiency and reduces the cost. And due to the process characteristics that no inner support is required during the shoveling and spinning process, it is particularly suitable for processing small-sized mandrels with an inner diameter of less than 20 mm. Brief Description of the Drawings

[0023] Figure 1 is a flowchart of a specific embodiment of the present invention.

[0024] Figure 2 is a processing technology diagram of a specific embodiment of the present invention.

[0025] Figure 3 is a processing technology diagram of shovel spinning in a specific embodiment of the present invention.

[0026] 1. spinning lower die; 2. boss; 3. shovel spinning wheel. Specific Embodiment

[0027] The present invention will be further described below in conjunction with the drawings and embodiments. It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific manner, and therefore cannot be construed as a limitation of the present invention. The terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0028] As Figure 1 shown, a processing technology of an engine pulley includes the following steps:

[0029] S1. Blanking: Prepare raw materials. In this embodiment, the raw material is in the shape of a round cake, which is obtained by punching on the raw material strip using a punching machine. The round cake shape is convenient for clamping by machine equipment. In other embodiments, it can also be punched into other shapes according to processing needs.

[0030] S2. Drawing: Use a 110-ton punching press to punch a boss 2 with a length greater than the final mandrel length in the center of the raw material in step S1 to provide material preparation for the subsequent steps. In this embodiment, the length of the boss 2 is 18 mm longer than the length of the final mandrel. In other embodiments, it can also be elongated by 15 - 20 mm according to the actual processing situation.

[0031] S3. Adopt the shovel spinning process to gather the drawn boss in step S2 towards the center to initially form a mandrel. In this embodiment, the diameter of the gathered boss is 0.8 mm smaller than the diameter of the final mandrel. In other embodiments, the diameter of the gathered boss can also be 0.5 - 1 mm smaller than the diameter of the final mandrel. Specifically, as Figure 3As shown, first, the boss 2 is fixed in the spinning lower die 1. The spinning lower die 1 drives the boss 2 to rotate around the center of the main shaft (not shown in the figure). The rotational speed of the main shaft is 300 - 500 RPM. The blade angle of the skiving roller is 90°, and the inclination angle is 45°. The skiving roller 3 advances horizontally from the edge of the boss 2 to form a mandrel.

[0032] S4. Use a hydraulic press to press down the whole mandrel in step S3. During the pressing process, wrap the outer circle of the mandrel and support its inner wall, so that the material fills the root area of the mandrel, forming a complete mandrel with consistent upper and lower parts.

[0033] S5. Use a bench drill to remove the excess material at the top of the mandrel in step S4 and drill a hole.

[0034] S6. Finish machining the lower pull outer ring in step S2 to make it the working surface where the pulley contacts the belt.

[0035] The processing technology of the engine pulley described in this application greatly simplifies the processing flow, significantly improves the processing efficiency and reduces the cost on the premise of ensuring the overall reliability of the product. And due to the process characteristics that no inner support is required during the skiving process, it is especially suitable for processing small-sized mandrels with an inner diameter of less than 20 mm.

[0036] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art shall be within the protection scope determined by the claims.

Claims

1. A processing technology for an engine pulley, characterized in that: The following steps are involved: S1, Cutting: Prepare raw materials; S2, stretching: stretching a boss on the raw material prepared in step S1; S3, shoveling and rotating: gather the bosses in step S2 toward the center to preliminarily form a mandrel; S4, shaping: pressing down the mandrel in step S3 as a whole to make it consistent from top to bottom; S5, opening a hole: removing the excess material on the top of the mandrel in step S4 and opening a hole; S6, spinning: the remaining outer ring after the boss is stretched in the spinning step S2 is pulled down to make it the working surface for the pulley to contact with the belt.

2. The processing technology of the engine pulley according to claim 1, characterized in that: In step S1, the raw material is in a round cake shape.

3. The processing technology of the engine pulley according to claim 1, characterized in that: In step S2, the boss is stretched out by stamping.

4. The processing technology of the engine pulley as claimed in claim 3, characterized in that: In step S2, the length of the boss is greater than the final mandrel length.

5. The processing technology of the engine pulley according to claim 4, characterized in that: The length of the boss is 15-20 mm longer than the length of the final mandrel.

6. The processing technology of the engine pulley according to any one of claims 1, 2 or 3, characterized in that: In step S3, the bosses are gathered toward the center by a shovel-turning process, and the diameter of the gathered bosses is 0.5-1 mm smaller than the diameter of the final mandrel.

7. The processing technology of the engine pulley according to claim 6, characterized in that: In step S3, the rotation speed of the scraper wheel is 300-500 RPM, the blade angle of the scraper wheel is 90°, and the inclination angle of the scraper wheel is 45°.

8. The processing technology of the engine pulley according to claim 1, characterized in that: In step S4, the mandrel is pressed down to wrap the outer circumference of the mandrel and support its inner wall.

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