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CN-117600466-B - Manufacturing process of encapsulated sprocket

CN117600466BCN 117600466 BCN117600466 BCN 117600466BCN-117600466-B

Abstract

The application relates to the technical field of powder metallurgy, in particular to a manufacturing process of an encapsulated sprocket, which comprises the following steps of S1 mixing materials according to mass percent, obtaining a mixture, S2 forming, namely molding the mixture into a sprocket green body under 600-800MPa, S3 sintering, namely sintering the sprocket green body for 30-45min under the condition of 1200-1280 ℃ and nitrogen, S4 shaping, namely pressurizing the sprocket green body again, correcting the sprocket green body to the required size to obtain a shaping piece, S5 steaming, namely steaming the shaping piece to form a compact oxide layer on the surface of the shaping piece, wherein a solution used for steaming consists of rust-proof oil and/or water, S6 performing surface treatment, namely sand blasting on the surface to be encapsulated, S7 performing encapsulation treatment, namely firstly applying an adhesive on the surface after sand blasting, then filling the sprocket into a mold, performing injection molding, and then vulcanizing to obtain the encapsulated sprocket. According to the application, through the process and the conditions, the encapsulated sprocket with extremely excellent encapsulation effect is obtained, and the peel strength of the adhesive tape is as high as 7.18-8.12 kN/m.

Inventors

  • ZHAO YUANJIN

Assignees

  • 迈格发(上海)科技股份有限公司

Dates

Publication Date
20260512
Application Date
20231113

Claims (7)

  1. 1. A manufacturing process of an encapsulated sprocket comprises the following steps: s1, mixing the raw materials uniformly according to the mass percentage to obtain a mixture; The raw materials in S1 comprise, by weight, 0.8-1.0wt.% of C, 2.0-3.2wt.% of Cu, 1.0-1.6wt.% of Mg, and Fe and unavoidable impurities as the rest; S2, forming, namely molding the mixture into a chain wheel green body at 600-800 MPa; The density of the molded sprocket green body in the step S2 is controlled to be 7.4-7.6g/cm 3 ; s3, sintering, namely sintering the green body of the chain wheel for 30-45min under the condition of 1200-1280 ℃ and nitrogen; s4, shaping, namely pressurizing the chain wheel green body again, and correcting the chain wheel green body to the required size to obtain a shaping piece; S5, steam treatment, namely performing steam treatment on the shaping piece to form a compact oxide layer on the surface of the shaping piece; The method is characterized in that a solution used for steam treatment consists of rust-preventive oil and/or water; S5, steam treatment is carried out in a multi-stage mode, and the specific steps are as follows: One-stage treatment, namely, treating at 300-450 ℃ for 5-10min by using rust-preventive oil as a solution; The second stage treatment, wherein the temperature is 500-550 ℃, the solution is prepared by mixing rust-proof oil and water, and the treatment time is 10-20min; three-stage treatment, namely, the temperature is 550-570 ℃, the solution is water, and the treatment time is 30-45min; S6, surface treatment, namely sand blasting the surface to be encapsulated; S7, coating an adhesive on the surface after sand blasting, filling the sprocket into a mold, performing injection molding, and vulcanizing to obtain the encapsulated sprocket.
  2. 2. The process for manufacturing the encapsulated sprocket as set forth in claim 1, wherein the rust preventive oil is one of R5133 and R5133A.
  3. 3. The process for manufacturing the encapsulated sprocket as set forth in claim 2, wherein said rust preventive oil and water are mixed in a weight ratio of 1 (5-10).
  4. 4. The process for manufacturing an encapsulated sprocket according to claim 1, wherein the surface to be encapsulated after sandblasting in S6 has a roughness less than or equal to Rz6.
  5. 5. The process for manufacturing an encapsulated sprocket as set forth in claim 1, wherein in S7 The adhesive consists of JL-499 and JL-480 in the weight ratio of 1 (1.2-1.5).
  6. 6. The process for manufacturing an encapsulated sprocket according to claim 1, wherein the material used for the injection in S7 is nitrile rubber and/or hydrogenated nitrile rubber.
  7. 7. The process for manufacturing the encapsulated sprocket as set forth in claim 1, wherein the vulcanization in S7 is carried out at a temperature of 175-180 ℃ for 15-20 minutes.

Description

Manufacturing process of encapsulated sprocket Technical Field The application relates to the technical field of powder metallurgy, in particular to a manufacturing process of an encapsulated sprocket. Background The sprocket wheel is a wheel with cog type sprocket teeth, which is used for meshing with blocks with accurate pitches on chain links or cables, and is widely applied to the field of transmission equipment due to good mechanical transmission performance, but the sprocket wheel is encapsulated due to the fact that the sprocket wheel is generally easy to wear. The rubber-coated sprocket is a special sprocket which can prevent metal from directly contacting metal by firmly bonding the metal and rubber through an adhesive, and can prevent the thin wall of the sprocket from directly contacting a chain through coated rubber in the use process, thereby playing a role in damping and noise reduction. In addition, the powder metallurgy is well known in the art and is characterized by being porous, so that residues are easily generated by capillary action of the surface of the liquid component, and the combination of the chain wheel framework and the rubber is greatly influenced; Therefore, the encapsulation technology in the related art often adopts surface densification to prevent impurities from entering gaps of a product, and adopts an oil baking treatment mode to remove oil in the product, but because the gaps cannot be completely sealed by the surface densification, liquid components are highly likely to enter the product again, and the encapsulation effect is further affected, so the encapsulation sprocket manufacturing technology with excellent encapsulation effect is particularly provided. Disclosure of Invention The invention aims to ensure the encapsulation effect as much as possible, obtains the encapsulation chain wheel with more stable encapsulation through optimizing and improving the process, and provides a manufacturing process of the encapsulation chain wheel. In a first aspect, a process for manufacturing an encapsulated sprocket comprises the steps of: s1, mixing the raw materials uniformly according to the mass percentage to obtain a mixture; S2, forming, namely molding the mixture into a chain wheel green body at 600-800 MPa; s3, sintering, namely sintering the green body of the chain wheel for 30-45min under the condition of 1200-1280 ℃ and nitrogen; s4, shaping, namely pressurizing the chain wheel green body again, and correcting the chain wheel green body to the required size to obtain a shaping piece; S5, steam treatment, namely performing steam treatment on the shaping piece to form a compact oxide layer on the surface of the shaping piece; The solution used for steam treatment consists of rust preventive oil and/or water; S6, surface treatment, namely sand blasting the surface to be encapsulated; S7, coating an adhesive on the surface after sand blasting, filling the sprocket into a mold, performing injection molding, and vulcanizing to obtain the encapsulated sprocket. By adopting the technical scheme, the encapsulated sprocket is prepared by the processes of mixing, forming, sintering, shaping, steam treatment, surface treatment and encapsulation in sequence, the encapsulation has excellent bonding effect, the peel strength of the adhesive tape is as high as 7.18-8.12kN/m, and the analysis of the reasons is possible as follows: The steam treatment realizes nearly synchronous rust prevention and densification due to the specificity of the solution, namely, rust prevention oil components are removed in the subsequent surface densification process after being soaked into the green body, and liquid and impurities are not easy to enter the gaps of the green body again in the operation process, so that the final encapsulation effect is ensured. Preferably, the raw materials in S1 consist of 0.8-1.0wt.% of C, 2.0-3.2wt.% of Cu, 1.0-1.6wt.% of Mg, and the balance of Fe and unavoidable impurities. Preferably, the green sprocket molded in S2 has a density of 7.4 to 7.6g/cm 3. By adopting the technical scheme, the rubber-coated sprocket prepared from the alloy components and the green density effectively ensures the processing easiness and the bonding strength with rubber, and the peeling strength of the rubber strip is as high as 7.96-8.11kN/m. Preferably, the steam treatment in S5 is a multistage, which comprises the following specific steps: One-stage treatment, namely, treating at 300-450 ℃ for 5-10min by using rust-preventive oil as a solution; The second stage treatment, wherein the temperature is 500-550 ℃, the solution is prepared by mixing rust-proof oil and water, and the treatment time is 10-20min; The three-stage treatment comprises 550-570 ℃ and 30-45min of solution which is water. Preferably, the rust preventive oil is one of R5133 and R5133A. Preferably, the rust preventive oil and water are mixed according to the weight ratio of 1 (5-10). By adopting the technical scheme, t