Process for manufacturing an encapsulated sprocket

Abstract

The application relates to the powder metallurgy technical field, in particular to a manufacturing process of a rubber-coated chain wheel, which comprises the following steps: S1, mixing: uniformly mixing raw materials according to mass percentage to obtain a mixture; S2, forming: forming the mixture into a chain wheel green body under the pressure of 600-800 MPa; S3, sintering: sintering the chain wheel green body under the temperature of 1200-1280 DEG C and in a nitrogen environment for 30-45 min; S4, shaping: pressurizing the chain wheel green body again to correct the required size to obtain a shaped piece; S5, steam treatment: performing steam treatment on the shaped piece to form a dense oxide layer on the surface; the solution used in the steam treatment is composed of rust-proof oil and / or water; S6, surface treatment: sand blasting the surface to be rubber-coated; S7, rubber-coating treatment: first, coating an adhesive on the surface after sand blasting, then, loading the chain wheel into a mold and performing injection molding, and then, vulcanizing, so that the rubber-coated chain wheel is obtained. Through the above process and conditions, the rubber-coated chain wheel with extremely excellent rubber-coating effect is obtained, and the peeling strength of the rubber strip of the rubber-coated chain wheel is as high as 7.18-8.12 kN / m.

Description

Technical Field

[0001] This application relates to the field of powder metallurgy technology, specifically to a manufacturing process for a rubber-coated sprocket. Background Technology

[0002] A sprocket is a wheel with interlocking teeth that meshes with precisely pitched blocks on a link chain or cable. Thanks to its excellent mechanical transmission performance, it is widely used in the field of transmission equipment. However, due to its tendency to wear, rubber-coated sprockets have emerged.

[0003] Rubber-coated sprockets are special sprockets that are made by firmly bonding metal and rubber together with an adhesive, preventing direct metal-to-metal contact. During use, the rubber coating prevents direct contact between the thin wall of the sprocket and the chain, thus reducing vibration and noise.

[0004] Furthermore, it is well known in the art that powder metallurgy is porous, so liquid components are very easy to leave residues due to surface capillary action, which in turn greatly affects the bonding between the sprocket skeleton and the rubber.

[0005] Therefore, the coating process in related technologies often uses surface densification to prevent impurities from entering the product's gaps, and uses oil drying to remove the oil inside the product. However, since surface densification cannot completely seal the gaps, liquid components are very likely to re-enter the product's interior, thus affecting the coating effect. Therefore, this paper provides a coating sprocket manufacturing process with excellent coating effect. Summary of the Invention

[0006] To ensure the best possible coating effect, this invention optimizes and improves the process to obtain a more stable coated sprocket, and hereby provides a manufacturing process for the coated sprocket.

[0007] Firstly, a manufacturing process for a rubber-coated sprocket includes the following steps:

[0008] S1. Mixing: Mix the raw materials evenly according to the mass percentage to obtain the mixture;

[0009] S2. Forming: The mixture is molded into a sprocket blank at 600-800MPa;

[0010] S3. Sintering: Sinter the sprocket green at 1200-1280℃ under nitrogen atmosphere for 30-45 minutes.

[0011] S4. Shaping: Apply pressure again to the sprocket blank and correct it to the required dimensions to obtain the shaped part;

[0012] S5. Steam treatment: The shaped parts are steam treated to form a dense oxide layer on their surface.

[0013] The solution used for steam treatment consists of rust-preventive oil and / or water;

[0014] S6. Surface treatment: Sandblast the surface to be coated;

[0015] S7. Rubber Coating: First, apply adhesive to the sandblasted surface, then install the sprocket into the mold and perform injection molding, followed by vulcanization to obtain the rubber-coated sprocket.

[0016] The rubber-coated sprockets produced by adopting the above technical solution and sequentially undergoing the above mixing, forming, sintering, shaping, steam treatment, surface treatment, and rubber coating processes exhibit excellent bonding performance, with a peel strength of 7.18-8.12 kN / m for the rubber strip. The reasons for this may be as follows:

[0017] Due to the special properties of the solution used in the above-mentioned steam treatment, rust prevention and densification are carried out almost simultaneously. That is, after the rust-preventive oil component is immersed in the green body, it will be removed in the subsequent surface densification process. During the operation, it is not easy for liquid and impurities to re-enter the gaps in the green body, thus ensuring the final coating effect.

[0018] Preferably, the raw material in S1 consists of the following weight percentages: C: 0.8-1.0 wt.%, Cu: 2.0-3.2 wt.%, Mg: 1.0-1.6 wt.%, with the balance being Fe and unavoidable impurities.

[0019] Preferably, the density of the sprocket blank molded in S2 is controlled to be 7.4-7.6 g / cm³. 3 .

[0020] By adopting the above technical solution, the rubber-coated sprocket made from the above alloy composition and green density effectively ensures the workability and bonding strength with rubber, and the peel strength of its rubber strip is as high as 7.96-8.11kN / m.

[0021] Preferably, the steam treatment in S5 is multi-stage, and the specific steps are as follows:

[0022] One-stage treatment: temperature 300-450℃, solution is rust-preventive oil, treatment time 5-10 minutes;

[0023] Two-stage treatment: temperature 500-550℃, solution prepared by mixing rust-preventive oil and water, treatment time 10-20 minutes;

[0024] Three-stage treatment: temperature 550-570℃, solution is water, treatment time 30-45min.

[0025] Preferably, the rust-preventive oil is one of R5133 and R5133A.

[0026] Preferably, the rust-preventive oil and water are mixed in a weight ratio of 1:(5-10).

[0027] By adopting the above technical solution, the above-mentioned first-stage treatment mainly achieves the wetting of the green blank through rust-preventive liquid and its steam, and is more thorough than the traditional oil immersion method;

[0028] In the subsequent second and third stages of processing, the surface can be densified while the oil is removed efficiently. Compared with the traditional baking oil method, the continuous operation and high temperature conditions reduce the possibility of liquid and impurities re-entering the gaps in the green body, thus ensuring the final coating effect.

[0029] Preferably, the roughness of the surface to be coated after sandblasting in S6 is less than or equal to Rz6.

[0030] Preferably, the adhesive in S7 is composed of JL-499 and JL-480 in a weight ratio of 1:(1.2-1.5).

[0031] Preferably, the material used for injection in S7 is nitrile rubber and / or hydrogenated nitrile rubber.

[0032] Preferably, the vulcanization conditions in S7 are: temperature 175-180℃ and time 15-20min.

[0033] By adopting the above technical solution, the rubber-coated sprockets produced under specific sandblasting, adhesive, injection, and vulcanization conditions have better bonding between the metal surface and the injection material, effectively giving the sprockets superior wear resistance, and are suitable for repeated rubber coating operations.

[0034] In summary, this application has the following beneficial effects:

[0035] 1. This application achieves near-simultaneous rust prevention and densification through a unique steam treatment. That is, after the rust-preventive oil component is immersed in the green body, it can be removed during the subsequent surface densification process. During the operation, it is not easy for liquid and impurities to re-enter the gaps in the green body, thus ensuring the coating effect.

[0036] 2. The rubber-coated sprocket made with specific alloy composition and green density in this application effectively balances mechanical properties and bonding strength with rubber, with a peel strength of 7.96-8.11 kN / m for the rubber strip;

[0037] 3. The rubber-coated sprockets made under specific sandblasting, adhesive, injection and vulcanization conditions in this application have better bonding between the metal surface and the injection material, and can effectively give the sprockets superior wear resistance. They are also suitable for repeated rubber coating operations, and can be re-coated after the surface rubber coating wears out. Detailed Implementation

[0038] The present application will be further described in detail below with reference to the embodiments.

[0039] Performance testing

[0040] First, select the rubber-coated sprocket (rubber thickness 10mm) from each embodiment and comparative example as the test sample. Then cut it along the width direction of the rubber strip, and then peel off 3cm along its length to leave the clamping part. The peeling angle is 90°, the test speed is 50mm / min, and the maximum peel strength is calculated.

[0041] Peel strength testing can be performed using clamps and a tensile testing machine. For specific testing standards and methods, please refer to GB / T41511-2022 "Test Method for Peel Strength of Coated Abrasives". Repeat the test 3 times and record the average value of the test results.

[0042] Examples 1-5

[0043] A rubber-coated sprocket, the components and their corresponding weight percentages are shown in the table below, and it is prepared by the following steps:

[0044] S1. Mixing: Mix the raw materials evenly according to the mass percentage to obtain the mixture;

[0045] S2. Molding: The mixture is molded into a sprocket blank at 800 MPa, and the density is controlled to be 7.5 g / cm³. 3 ;

[0046] S3, Sintering: Sinter the sprocket green at 1280℃ under nitrogen atmosphere for 30 minutes;

[0047] S4. Shaping: Apply pressure again to the sprocket blank and correct it to the required dimensions to obtain the shaped part;

[0048] S5. Steam Treatment: The shaped parts undergo multi-stage steam treatment, with the specific steps as follows:

[0049] One-stage treatment: temperature 300℃, solution is rust-preventive oil, treatment time 10 minutes;

[0050] The rust-preventive oil is R5133, which is sourced from Sinopec Lubricating Oil Co., Ltd.

[0051] Two-stage treatment: temperature 550℃, solution prepared by mixing rust-preventive oil and water, treatment time 20min;

[0052] The rust-preventive oil and water are mixed in a weight ratio of 1:5;

[0053] Three-stage treatment: temperature 570℃, solution is water, treatment time 45min;

[0054] S6. Surface treatment: Sandblast the surface to be coated with adhesive to control its roughness to be equal to Rz6;

[0055] S7. Coating treatment: First, apply a 0.5mm thick adhesive to the sandblasted surface. The adhesive is composed of JL-499 and JL-480 (purchased from Juli Adhesive Industry) in a weight ratio of 1:1.2.

[0056] Next, the sprocket coated with adhesive is placed into the mold, and hydrogenated nitrile rubber is added for injection molding. Then, it is vulcanized at 180°C for 15 minutes to obtain the rubber-coated sprocket.

[0057] Table: Components and their weight percentages in Examples 1-5

[0058]

[0059] Comparative Example 1

[0060] A rubber-coated sprocket, differing from Example 1, includes the following steps:

[0061] S1. Mixing: Mix the raw materials evenly according to the mass percentage to obtain the mixture;

[0062] S2. Molding: The mixture is molded into a sprocket blank at 800 MPa, and the density is controlled to be 7.5 g / cm³. 3 ;

[0063] S3, Sintering: Sinter the sprocket green at 1280℃ under nitrogen atmosphere for 30 minutes;

[0064] S4. Oil immersion: Immerse the sintered sprocket blank in rust-preventive oil, which is R5133.

[0065] S5. Shaping: Place the oil-soaked sintered sprocket in the mold and pressurize it again to 800MPa to correct the dimensional tolerances of the gear and improve its accuracy;

[0066] S6. Steam treatment: The shaped part is steam treated in a continuous steam furnace at 600℃ for 30 minutes until a dense oxide layer is formed on the surface of the shaped part.

[0067] S7. Surface treatment: Sandblast the surface to be coated with adhesive to control its roughness to be equal to Rz6;

[0068] S8. Coating treatment: First, apply a 0.5mm thick adhesive to the sandblasted surface. The adhesive is composed of JL-499 and JL-480 (purchased from Juli Adhesive Industry) in a weight ratio of 1:1.2.

[0069] Next, the sprocket coated with adhesive is placed into the mold, and hydrogenated nitrile rubber is added for injection molding. Then, it is vulcanized at 180°C for 15 minutes to obtain the rubber-coated sprocket.

[0070] Comparative Example 2

[0071] A rubber-coated sprocket, differing from Example 1, includes the following steps:

[0072] S1. Mixing: Mix the raw materials evenly according to the mass percentage to obtain the mixture;

[0073] S2. Molding: The mixture is molded into a sprocket blank at 680 MPa, and the density is controlled to be 7.0 g / cm³. 3 ;

[0074] S3, Sintering: Sinter the sprocket green at 1120℃ under nitrogen atmosphere for 30 minutes;

[0075] S4. Oil immersion: Immerse the sintered sprocket blank in rust-preventive oil, which is PM-3.

[0076] S5. Shaping: Place the oil-soaked sintered sprocket in the mold and pressurize it again to 800MPa to correct the dimensional tolerances of the gear and improve its accuracy;

[0077] S6. Steam treatment: The shaped part is steam treated in a continuous steam furnace at 600℃ for 30 minutes until a dense oxide layer is formed on the surface of the shaped part.

[0078] S7. Surface treatment: Sandblast the surface to be coated with adhesive to control its roughness to be equal to Rz6;

[0079] S8. Coating treatment: First, apply a 0.5mm thick adhesive to the sandblasted surface. The adhesive is composed of JL-499 and JL-480 (purchased from Juli Adhesive Industry) in a weight ratio of 1:1.2.

[0080] Next, the sprocket coated with adhesive is placed into the mold, and hydrogenated nitrile rubber is added for injection molding. Then, it is vulcanized at 175°C for 30 minutes to obtain the rubber-coated sprocket.

[0081] Extract the rubber-coated sprockets from Examples 1-5 and Comparative Examples 1-2 above, and test their peel strength according to the above steps and standards. The average value of the test results is recorded in the table below.

[0082] Table: Performance test results of Examples 1-5 and Comparative Example 1

[0083]

[0084] As can be seen from the table above, the rubber-coated sprockets prepared in Examples 1-5 all have excellent rubber coating effects, and the peel strength of their rubber strips is as high as 7.96-8.11kN / m, which is improved to varying degrees compared with any group in Comparative Examples 1-2.

[0085] The reasons for this may be as follows: Due to the special nature of the solution and process used in the above steam treatment, rust prevention and densification are carried out almost simultaneously. That is, after the rust-preventive oil component is immersed in the green body, it will be removed in the subsequent surface densification process. During the operation, it is not easy for liquid and impurities to re-enter the gaps in the green body, thus ensuring the final coating effect.

[0086] Obviously, Comparative Examples 1-2 cannot achieve the above effect. Because S7 is after S4 and the surface densification cannot completely seal the gaps, liquid components and impurities are very likely to re-enter the product in processes such as S5, which affects the coating effect and significantly reduces the peel strength of the adhesive strip.

[0087] As can be seen from Examples 1-5, the preferred ratio of raw materials is as follows: C: 0.8-1.0 wt.%, Cu: 2.0-3.2 wt.%, Mg: 1.0-1.6 wt.%, with the balance being Fe and unavoidable impurities. Adjustments within this range are unlikely to have a significant impact on product performance; the minor fluctuations mainly stem from controlling the green body density to 7.5 g / cm³. 3 Afterwards, the size of the internal gaps became inconsistent.

[0088] Example 6

[0089] A rubber-coated sprocket differs from Example 1 in that the density of the sprocket blank in S2 is controlled to be 7.4 g / cm³. 3 .

[0090] Example 7

[0091] A rubber-coated sprocket differs from Example 1 in that the density of the sprocket blank in S2 is controlled to be 7.6 g / cm³. 3 .

[0092] Example 8

[0093] A rubber-coated sprocket differs from Example 1 in that the density of the sprocket blank in S2 is controlled to be 7.8 g / cm³. 3 .

[0094] Extract the rubber-coated sprockets from Examples 6-8 above, and test their peel strength according to the above steps and standards. The average value of the test results is recorded in the table below.

[0095] Table: Performance Test Results of Examples 6-8

[0096]

[0097] As can be seen from the table above, the rubber-coated sprockets prepared in Examples 1 and 6-8 all exhibit excellent rubber coating effects, with peel strength of the rubber strip reaching 7.96-8.12 kN / m. Therefore, the preferred density range for the sprocket blank is 7.4-7.6 g / cm³. 3 ;

[0098] Furthermore, within this range, the peel strength of the adhesive strip increases with the increase of density. However, beyond this range, such as in Example 8, the peel strength performance no longer increases, and it also easily affects the shaping process of S4, resulting in poor processability.

[0099] Example 9

[0100] A rubber-coated sprocket differs from Example 1 in that the steam treatment step in S5 is as follows:

[0101] One-stage treatment: temperature 300℃, solution is rust-preventive oil, treatment time 10 minutes;

[0102] The rust-preventive oil is R5133, which is sourced from Sinopec Lubricating Oil Co., Ltd.

[0103] Two-stage treatment: temperature 550℃, solution prepared by mixing rust-preventive oil and water, treatment time 65min;

[0104] The rust-preventive oil and water are mixed in a weight ratio of 1:5.

[0105] Example 10

[0106] A rubber-coated sprocket differs from Example 1 in that the steam treatment step in S5 is as follows:

[0107] One-stage treatment: temperature 300℃, solution is rust-preventive oil, treatment time 10 minutes;

[0108] The rust-preventive oil is R5133, which is sourced from Sinopec Lubricating Oil Co., Ltd.

[0109] Two-stage treatment: temperature 550℃, solution is water, treatment time 65min.

[0110] Example 11

[0111] A rubber-coated sprocket differs from Example 1 in that the steam treatment step in S5 is as follows:

[0112] One-stage treatment: temperature 450℃, solution is rust-preventive oil, treatment time 5 minutes;

[0113] The rust-preventive oil is R5133, which is sourced from Sinopec Lubricating Oil Co., Ltd.

[0114] Two-stage treatment: temperature 500℃, solution prepared by mixing rust-preventive oil and water, treatment time 20 minutes;

[0115] The rust-preventive oil and water are mixed in a weight ratio of 1:5;

[0116] Three-stage treatment: temperature 550℃, solution is water, treatment time 30min.

[0117] Example 12

[0118] A rubber-coated sprocket differs from Example 1 in that the rust-preventive oil is R5133A, sourced from Sinopec Lubricating Oil Co., Ltd.

[0119] Extract the rubber-coated sprockets from Examples 9-12 above, and test their peel strength according to the above steps and standards. The average value of the test results is recorded in the table below.

[0120] Table: Performance Test Results of Examples 9-12

[0121]

[0122] As can be seen from the table above, the rubber-coated sprockets prepared in Examples 1 and 9-12 all have excellent rubber coating effects, and the peel strength of their rubber strips is as high as 7.18-7.96kN / m. It can be seen that the preferred steam treatment steps are three stages, and the adjustment within a specific range and the selection of rust-preventive oil have little impact on performance.

[0123] Based on the various embodiments, the specific reasons may be as follows:

[0124] The first stage of the process mainly involves wetting the green blank with rust-preventive liquid and its steam, which is more thorough than the traditional oil immersion method. The subsequent second and third stages of the process can achieve surface densification while efficiently removing oil. Compared with the traditional baking oil method, the continuous operation and high temperature conditions reduce the possibility of liquid and impurities re-entering the gaps in the green blank, thus ensuring the final coating effect.

[0125] Example 13

[0126] A rubber-coated sprocket differs from Example 1 in that the rust-preventive oil and water in the second stage of S5 are mixed at a weight ratio of 1:8.

[0127] Example 14

[0128] A rubber-coated sprocket differs from Example 1 in that the rust-preventive oil and water in the second stage of treatment in S5 are mixed at a weight ratio of 1:10.

[0129] Example 15

[0130] A rubber-coated sprocket differs from Example 1 in that the rust-preventive oil and water in the second stage of treatment in S5 are mixed at a weight ratio of 1:20.

[0131] Extract the rubber-coated sprockets from Examples 13-15 above, and test their peel strength according to the above steps and standards. The average value of the test results is recorded in the table below.

[0132] Table: Performance Test Results of Examples 13-15

[0133]

[0134] As can be seen from the table above, the rubber-coated sprockets prepared in Examples 1 and 13-15 all have excellent rubber coating effects, and the peel strength of their rubber strips is as high as 7.87-8.01kN / m. It can be seen that the preferred weight ratio of rust-preventive oil and water in the second stage of S5 is 1:(5-10). In addition, the ratio adjustment within this specific range has little impact on performance, but exceeding this ratio will cause the performance to decline. The reason for this may be that the content of rust-preventive oil in the second stage of treatment is too low, which affects the degreasing effect, and the liquid residue affects the final rubber coating effect.

[0135] Example 16

[0136] A rubber-coated sprocket, which differs from Example 1 in that the adhesive in S7 is JL-499.

[0137] Example 17

[0138] A rubber-coated sprocket, which differs from Example 1 in that the adhesive in S7 is JL-480.

[0139] Example 18

[0140] A rubber-coated sprocket, which differs from Example 1 in that the adhesive in S7 is composed of JL-499 and JL-480 in a weight ratio of 1:1.4.

[0141] Example 19

[0142] A rubber-coated sprocket, which differs from Example 1 in that the adhesive in S7 is composed of JL-499 and JL-480 in a weight ratio of 1:1.5.

[0143] Example 20

[0144] A rubber-coated sprocket, which differs from Example 1 in that the adhesive in S7 is composed of JL-499 and JL-480 in a weight ratio of 1:2.

[0145] Extract the rubber-coated sprockets from Examples 16-20 above, and test their peel strength according to the above steps and standards. The average value of the test results is recorded in the table below.

[0146] Table: Performance Test Results of Examples 16-20

[0147]

[0148] As can be seen from the table above, the rubber-coated sprockets prepared in Examples 1 and 16-20 all have excellent rubber coating effects, and the peel strength of their rubber strips is as high as 7.21-7.96kN / m. It can be seen that the binder in S7 is preferably composed of JL-499 and JL-480 in a weight ratio of 1:(1.2-1.5).

[0149] Furthermore, based on the above embodiments, it can be seen that JL-499 and JL-480 have a certain composite effect. When used alone, JL-480 is the preferred example. However, when the two are combined, the proportion of JL-480 should not be too high. The reason for this may be related to the bonding method of the two.

[0150] Example 21

[0151] A rubber-coated sprocket, which differs from Example 1 in that the material used for injection in S7 is nitrile rubber.

[0152] Example 22

[0153] A rubber-coated sprocket differs from Example 1 in that the material used for injection in S7 is composed of nitrile rubber and hydrogenated nitrile rubber in a weight ratio of 1:1.

[0154] Example 23

[0155] A rubber-coated sprocket differs from Example 1 in that the vulcanization conditions in S7 are: temperature 175°C and time 20 min.

[0156] Example 24

[0157] A rubber-coated sprocket differs from Example 21 in that the vulcanization conditions in S7 are: temperature 175°C and time 20 min.

[0158] Example 25

[0159] A rubber-coated sprocket differs from Example 22 in that the vulcanization conditions in S7 are: temperature 175°C and time 20 min.

[0160] Extract the rubber-coated sprockets from Examples 21-25 above, and test their peel strength according to the above steps and standards. The average value of the test results is recorded in the table below.

[0161] Table: Performance Test Results of Examples 21-25

[0162]

[0163] As can be seen from the table above, the rubber-coated sprockets prepared in Examples 1 and 21-25 all have excellent rubber coating effects, and the peel strength of their rubber strips is as high as 7.81-7.96kN / m. It can be seen that the preferred injection material in S7 is hydrogenated nitrile rubber, and the preferred vulcanization conditions are a temperature of 175-180℃ and a time of 15-20min.

[0164] Furthermore, based on the above embodiments, it can be seen that the injection materials can be either nitrile rubber or hydrogenated nitrile rubber, but they should not be mixed together. The reason for this may be related to their bonding and vulcanization methods.

[0165] Furthermore, as can be seen from Examples 23-25, under specific vulcanization conditions of 175-180℃ and 15-20min, rubber coating can be preferably achieved. In general, the rubber coating effect of the rubber strip will be further improved with the extension of vulcanization time, and the peel strength will be improved to varying degrees.

[0166] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A manufacturing process for a rubber-coated sprocket, comprising the following steps: S1. Mixing: Mix the raw materials evenly according to the mass percentage to obtain the mixture; The raw materials in S1 consist of the following components by weight percentage: C: 0.8-1.0 wt.%, Cu: 2.0-3.2 wt.%, Mg: 1.0-1.6 wt.%, balance being Fe and unavoidable impurities; S2. Forming: The mixture is molded into a sprocket blank at 600-800MPa; The density of the sprocket blank molded in S2 is controlled at 7.4-7.6 g / cm³. 3 ; S3. Sintering: Sinter the sprocket green at 1200-1280℃ under nitrogen atmosphere for 30-45 minutes. S4. Shaping: Apply pressure again to the sprocket blank and correct it to the required dimensions to obtain the shaped part; S5. Steam treatment: The shaped parts are steam treated to form a dense oxide layer on their surface. The characteristic feature is that the solution used for steam treatment consists of rust-preventive oil and / or water; Steam treatment in S5 is multi-stage, and its specific steps are as follows: One-stage treatment: temperature 300-450℃, solution is rust-preventive oil, treatment time 5-10 minutes; Two-stage treatment: temperature 500-550℃, solution prepared by mixing rust-preventive oil and water, treatment time 10-20 minutes; Three-stage treatment: temperature 550-570℃, solution is water, treatment time 30-45min; S6. Surface treatment: Sandblast the surface to be coated; S7. Rubber Coating: First, apply adhesive to the sandblasted surface, then install the sprocket into the mold and perform injection molding, followed by vulcanization to obtain the rubber-coated sprocket.

2. The manufacturing process of the rubber-coated sprocket according to claim 1, characterized in that, The rust-preventive oil is one of R5133 or R5133A.

3. The manufacturing process of the rubber-coated sprocket according to claim 2, characterized in that, The rust-preventive oil and water are mixed at a weight ratio of 1:(5-10).

4. The manufacturing process of the rubber-coated sprocket according to claim 1, characterized in that, The roughness of the surface to be coated after sandblasting in S6 is less than or equal to Rz6.

5. The manufacturing process of the rubber-coated sprocket according to claim 1, characterized in that, S7 The adhesive is composed of JL-499 and JL-480 in a weight ratio of 1:(1.2-1.5).

6. The manufacturing process of the rubber-coated sprocket according to claim 1, characterized in that, The materials used for injection molding in S7 are nitrile rubber and / or hydrogenated nitrile rubber.

7. The manufacturing process of the rubber-coated sprocket according to claim 1, characterized in that, The vulcanization conditions in S7 are: temperature 175-180℃ and time 15-20min.

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