Forming die for rubber guide sleeve with metal skeleton and method for producing same

Abstract

The application discloses a forming die of a rubber guide sleeve with a metal framework and a preparation method thereof. The forming die comprises an upper die, a middle die and a lower die. The upper die comprises an upper disc and a cylinder. The cylinder is provided with a positioning hole. The lower surface of the upper disc is provided with a chamfered upper cavity groove. The lower die comprises a lower disc, a circular table and a positioning boss. The upper surface of the circular table is provided with a chamfered lower cavity groove. The middle die is provided with a cavity hole in the center. When the die is closed, the positioning boss of the lower die is inserted into the positioning hole. The positioning boss is provided with a support ring which is provided with a recess forming pin. The outer wall of the cylinder is provided with a metal framework. The chamfered upper cavity groove, the outer wall of the cylinder, the outer side wall of the support ring, the chamfered lower cavity groove and the inner wall of the cavity hole form a forming cavity. After vulcanization of the product is completed, the forming pin is accurately positioned, the square recess around the inner diameter of the metal framework guide sleeve meets the design requirements, the die opening and the product demolding are smooth, the operation is simple, safe and reliable, and the manufacturing cost is low.

Description

Technical Field

[0001] This invention relates to the field of rubber guide sleeve technology, specifically a molding die for a rubber guide sleeve with a metal skeleton and its preparation method. Background Technology

[0002] The production of rubber products involves essential steps, including raw rubber processing, plasticizing, mixing, molding, vulcanization, finishing, and inspection. Vulcanization is the key process, playing a decisive role in the quality of the rubber products. Therefore, the molds used for rubber vulcanization are particularly important, as their quality directly affects the quality, cost, and energy consumption of the rubber products. The design of rubber molds must meet the requirements of the product's use, ensure product quality, and feature a simple and reasonable structure, reliable positioning, an appropriate number of cavities, and ease of processing and use. Ease of operation and low cost are also crucial technical factors.

[0003] General-purpose elastic guide sleeves are typically made of pure rubber, polyurethane, or plastic. The product has a simple structure, and its technical parameters include inner diameter, outer diameter, and height. The molds are also relatively simple, requiring only an upper mold, middle mold, lower mold, and core mold to form a sealed cavity. Product removal is simple and convenient, the mold processing is relatively easy, and the operation is relatively safe.

[0004] The guide sleeve with a metal skeleton has four grooves evenly distributed around its inner diameter, and the upper part of the grooves is a non-deformable metal skeleton. Conventional mold design must consider the ejection mechanism and demolding mechanism. The following special requirements are added to the mold design and process design: the metal skeleton must be able to be smoothly embedded in the rubber, firmly bonded, not allowed to delaminate, and not deformed, and the position must meet the design requirements; during the vulcanization process of the product, the metal skeleton is not allowed to be displaced due to rubber creep or pressure; after the product is vulcanized, it is required to be able to be demolded quickly.

[0005] Due to the special nature of the structure, the vulcanization heating equipment required for manufacturing the product has very high installation requirements. In actual production, after the product has completed vulcanization, it is not easy to demold smoothly, resulting in high production costs and complicated operation.

[0006] In summary, compared to ordinary elastic guide sleeves, rubber guide sleeves with metal skeletons require special positioning methods and structures in mold design and manufacturing processes to ensure design requirements are met, thereby reducing costs and improving efficiency. Summary of the Invention

[0007] The purpose of this invention is to provide a molding die for a rubber guide sleeve with a metal skeleton and its preparation method. Through the precise matching of the upper die, middle die, lower die, and the support ring and groove forming pin installed on the lower die, the forming pin is accurately positioned after the product vulcanization is completed. The square groove around the inner diameter of the metal skeleton guide sleeve meets the design requirements. Moreover, the mold opening and product demolding are smooth, the operation is simple, safe and reliable, and the manufacturing cost is low.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A molding die for a rubber guide sleeve with a metal skeleton is disclosed. The guide sleeve, made of rubber, has a circular metal skeleton in the center of its inner wall. Four blind holes are evenly distributed on the inner wall below the metal skeleton. The molding die includes an upper die, a middle die, and a lower die. The upper die includes an integrally formed coaxial upper disk and a cylinder. The outer diameter of the cylinder matches the inner diameter of the rubber guide sleeve. A positioning hole, coaxial with the cylinder, is formed at the center of the cylinder. A circular chamfered upper cavity groove is formed on the lower surface of the upper disk, adjacent to the connection between the cylinder and the upper disk. The lower die includes an integrally formed coaxial lower disk, a frustum, and a positioning boss. The outer diameter of the positioning boss matches the inner diameter of the positioning hole. A circular chamfered lower cavity groove is formed on the upper surface of the frustum, and the chamfered lower cavity groove is vertically symmetrical to the chamfered upper cavity groove. A cylindrical middle die is mounted on the lower die. Between the upper mold and the middle mold, a cavity hole coaxial with the middle mold is opened in the center, and the diameter of the cavity hole is adapted to the outer diameter of the rubber guide sleeve to be prepared. When the mold is closed, the positioning boss of the lower mold is inserted into the positioning hole. A support ring is fitted on the outer wall of the positioning boss. Four radially arranged groove forming pins are symmetrically placed on the upper surface of the support ring. The upper surface of the support ring abuts against the lower surface of the cylinder. A metal skeleton is installed on the lower part of the outer wall of the cylinder. The lower surface of the metal skeleton abuts against the edge of the upper surface of the support ring. The chamfered upper cavity groove, the outer wall of the cylinder, the outer wall of the support ring, the chamfered lower cavity groove, and the inner wall of the cavity hole form the forming cavity of the guide sleeve to be prepared. A positioning inclined surface adapted to the outer wall of the lower mold's truncated cone is opened on the lower side wall of the cavity hole. A circular downward flow groove is opened at the connection between the middle mold and the lower mold plane. A circular upward flow groove is opened at the connection between the middle mold and the upper mold.

[0010] Preferably, the outer edge of the upper surface of the middle mold has several upper mold opening grooves.

[0011] Preferably, the frustum is a two-stage stepped frustum, the upper mold step is a cylinder, the diameter of the cylinder is adapted to the outer diameter of the support ring and the inner diameter of the rubber guide sleeve to be prepared, and the outer wall of the lower mold step is an inclined surface with an inclination angle of 10-15°.

[0012] Preferably, the positioning inclined surface is adapted to the shape of the lower frustum of the truncated cone, and after the mold is closed, there is a gap between the bottom surface of the middle mold and the upper surface of the lower disk of the lower mold. This gap is the lower mold opening groove when the middle mold and the lower mold are opened.

[0013] Preferably, the support ring is a circular plate, the diameter of the inner hole of the support ring is adapted to the outer diameter of the positioning boss, the outer diameter of the support ring is adapted to the outer diameter of the cylinder, four pin holes are evenly distributed on the outer side of the inner hole of the support ring, and a recessed groove extending to its outer edge is formed on the upper surface of the support ring outside the pin hole. The shape of the pin hole and the recessed groove are adapted to the shape of the groove forming pin.

[0014] Preferably, the groove forming pin is an L-shaped strip plate, with the short side of the groove forming pin inserted into the pin hole and the long side installed in the recessed groove and extending out of the outer edge of the support ring. After the groove forming pin is installed on the support ring, the upper surface of the groove forming pin is flush with the upper surface of the support ring.

[0015] Preferably, the shape of the portion of the long side of the grooved pin extending to the outer edge of the support ring is adapted to the shape of the blind hole below the metal skeleton of the rubber guide sleeve to be prepared.

[0016] Preferably, the chamfered upper cavity groove and the chamfered lower cavity groove are adapted to the shapes of the top and bottom of the guide sleeve to be prepared, respectively.

[0017] A method for forming a rubber guide sleeve with a metal skeleton, the method being implemented using the aforementioned forming mold for the rubber guide sleeve with a metal skeleton, includes the following steps:

[0018] Step 1: Pre-treatment of the metal skeleton:

[0019] First, clean the oil stains on the surface of the metal frame with gasoline, then soak it in dilute acid for 5-12 hours to remove rust. Next, rinse the surface of the metal frame with hot water at 80-90℃. After drying, apply a layer of metal-rubber adhesive to the bonding surface with the rubber. Let it stand at room temperature for 30 minutes, then apply a second layer of metal-rubber adhesive and let it stand for 2 hours before use.

[0020] Step 2: Rubber Preparation

[0021] The plasticized raw rubber for preparing the rubber guide sleeve is placed in the mixing chamber of the internal mixer. Various additives are added according to the process requirements. After all the mixture is mixed, the machine is started to mix and obtain a semi-finished compound rubber product. The semi-finished compound rubber product is taken out of the internal mixer and cooled. When the temperature of the semi-finished compound rubber product drops to below 30°C, the semi-finished compound rubber product is put into the mill again, a crosslinking agent is added, and it is mixed evenly. The mixed rubber is then discharged from the sheet and cooled to obtain a compound rubber sheet. The compound rubber sheet is then cut into the required specifications.

[0022] Step 3: Mold closing and vulcanization:

[0023] Place the lower mold on the lower platen of the vulcanizing machine, place the support ring on the upper surface of the lower mold's frustum, and assemble the grooved forming pin into the recessed groove of the support ring. The top of the long side of the grooved forming pin extends out of the outer edge of the support ring. Then, place the metal skeleton, which has been pretreated in step one and coated with metal-rubber adhesive, on the upper surface of the support ring. Place the middle mold on the lower mold, so that the inclined surface of the frustum fits against the mating inclined surface of the lower part of the middle mold. Put an appropriate amount of the mixed rubber sheet prepared in step two into the molding cavity, assemble the upper mold onto the lower mold, and control the upper platen of the vulcanizing machine to gradually descend. The upper platen applies pressure to the mold, and the upper mold, middle mold, and lower mold close. Set the temperature, time, and pressure according to the process requirements to carry out vulcanization molding.

[0024] Step 4: Demolding

[0025] After vulcanization is completed, the platen on the vulcanizing machine is raised, and the operator inserts a tool into the upper mold opening groove to open the upper mold. Then the middle mold is moved upward, and the formed rubber guide sleeve is moved out along with the middle mold. The four groove forming pins stuck under the metal ring are removed from the rubber guide sleeve and placed back into the sinking groove of the support ring for use in the production of the next product. After the rubber guide sleeve passes inspection, it is put into storage.

[0026] Preferably, the surface roughness Ra of the molding cavity is maintained at .

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) The present invention assembles an upper mold, a middle mold and a lower mold to form a molding cavity for the guide sleeve to be prepared by chamfering the upper cavity groove, the outer wall of the cylinder, the outer wall of the support ring, chamfering the lower cavity groove and the inner wall of the cavity hole. The front ends of the four grooved molding pins assembled on the support ring extend out of the edge of the support ring. The front ends of the grooved molding pins form a groove under the metal skeleton of the rubber guide sleeve during the vulcanization process of the film. The metal skeleton is bonded to the side wall of the upper mold. The support ring supports the metal skeleton, ensuring the accurate positioning of the metal skeleton and preventing displacement during the vulcanization process of the film.

[0029] (2) The positioning hole at the center of the upper mold is matched with the positioning boss at the center of the lower mold. The lower side wall of the cavity hole of the middle mold is provided with a positioning inclined surface that matches the outer wall of the truncated cone of the lower mold. When the mold is closed, the positioning boss of the lower mold is inserted into the positioning hole. The H7 / h6 clearance fit is adopted. The positioning inclined surface is in contact with the outer wall of the truncated cone, which avoids the lateral movement of the upper and lower molds, makes the mold assembly stable, and ensures the forming size of the product.

[0030] (3) In this invention, a circular downward flow groove is provided at the connection between the middle mold and the lower mold plane, and a circular upward flow groove is provided at the connection between the middle mold and the upper mold. This facilitates the venting and discharge of excess rubber material during the vulcanization process, reducing surface scars and air-filling defects on the product.

[0031] (4) The present invention provides an upper mold opening groove around the upper surface of the middle mold and a lower mold opening groove between the lower surface of the middle mold and the upper surface of the lower disk of the lower mold. The mold opening groove is not connected to the molding cavity, and is used to open the mold smoothly and take out the product.

[0032] (5) The surface roughness of the molding cavity in this invention is This facilitates product demolding;

[0033] (6) In this invention, the upper mold, middle mold and lower mold are all made of mold steel. The molds are fitted together with a precise small clearance, which can open the mold smoothly and prevent them from moving around. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the rubber guide sleeve.

[0035] Figure 2 This is a schematic diagram of the mold structure;

[0036] Figure 3 It is an exploded view of the mold;

[0037] Figure 4 This is a structural diagram of the upper mold.

[0038] Figure 5 This is a structural schematic diagram of the intermediate mold;

[0039] Figure 6 This is a schematic diagram of the lower mold structure;

[0040] Figure 7 This is a schematic diagram of the support ring structure;

[0041] Figure 8 This is a schematic diagram of the groove-formed pin structure;

[0042] Figure 9 This is a schematic diagram of the grooved pin being assembled onto the support ring;

[0043] In the diagram: 1. Upper mold, 2. Middle mold, 3. Groove forming pin, 4. Lower mold, 5. Support ring, 6. Upper disc, 7. Cylinder, 8. Positioning hole, 9. Chamfered upper cavity groove, 10. Lower disc, 11. Frustum, 12. Positioning boss, 13. Chamfered lower cavity groove, 14. Cavity hole, 15. Upper mold opening groove, 16. Positioning slope, 17. Metal skeleton, 18. Upper glue channel, 19. Lower glue channel, 20. Sunken groove, 21. Blind hole, 22. Lower mold opening groove, 23. Pin hole. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings.

[0045] like Figures 1 to 9 The diagram shows a molding die for a rubber guide sleeve with a metal skeleton. A circular metal skeleton 17 is provided in the center of the inner wall of the rubber guide sleeve to be manufactured. Four blind holes 21 are evenly distributed on the inner wall below the metal skeleton 17. The die includes an upper mold 1, a middle mold 2, and a lower mold 4. The upper mold 1 includes an integrally formed coaxial upper disk 6 and a cylinder 7. The outer diameter of the cylinder 7 is adapted to the inner diameter of the rubber guide sleeve to be manufactured. A positioning hole 8, coaxial with the cylinder 7, is opened at the center of the cylinder 7. The lower part of the upper disk 6... The lower mold 4 has an annular chamfered upper cavity groove 9 on its surface, which is adjacent to the connection between the cylinder 7 and the upper disk 6. The lower mold 4 includes an integrally formed coaxial lower disk 10, a frustum 11, and a positioning boss 12. The outer diameter of the positioning boss 12 is adapted to the inner diameter of the positioning hole 8. An annular chamfered lower cavity groove 13 is formed on the upper surface of the frustum 11. The chamfered lower cavity groove 13 and the chamfered upper cavity groove 9 are vertically symmetrical. The cylindrical middle mold 2 is installed on the lower mold 4 and the upper mold 6. Between them, the center of the middle mold 2 has a cavity hole 14 coaxial with it, the diameter of the cavity hole 14 is adapted to the outer diameter of the rubber guide sleeve to be prepared; when the mold is closed, the positioning boss 12 of the lower mold 4 is inserted into the positioning hole 8, and a support ring 5 is fitted on the outer wall of the positioning boss 12. Four radially arranged groove forming pins 3 are symmetrically placed on the upper surface of the support ring 5. The upper surface of the support ring 5 abuts against the lower surface of the cylinder 7. A metal frame 17 is installed on the lower part of the outer wall of the cylinder 7. The lower part of the metal frame 17 The surface abuts against the edge of the upper surface of the support ring 5; the chamfered upper cavity groove 9, the outer wall of the cylinder 7, the outer wall of the support ring 5, the chamfered lower cavity groove 13, and the inner wall of the cavity hole 14 form the forming cavity of the guide sleeve to be prepared; the lower side wall of the cavity hole 14 is provided with a positioning slope 16 that matches the outer wall of the frustum 11 of the lower mold 4, and an annular lower glue groove 19 is provided at the connection between the positioning slope 16 and the frustum 11, and an annular upper glue groove 18 is provided at the connection between the middle mold 2 and the upper mold 1.

[0046] Several upper mold opening grooves 15 are provided on the outer edge of the upper surface of the middle mold 2.

[0047] Frustum 11 is a two-stage stepped frustum. The upper step is a cylinder with a diameter that matches the outer diameter of the support ring and the inner diameter of the rubber guide sleeve to be prepared. The outer wall of the lower step is an inclined surface with an inclination angle of 10-15°.

[0048] The positioning inclined surface 16 is adapted to the shape of the lower truncated cone of the cone 11. After the mold is closed, there is a gap between the bottom surface of the middle mold 2 and the upper surface of the lower disc 10 of the lower mold 4. This gap is the lower mold opening groove 22 when the middle mold 2 and the lower mold 4 are opened.

[0049] The support ring 5 is a circular plate. The diameter of the inner hole of the support ring 5 is adapted to the outer diameter of the positioning boss 12. The outer diameter of the support ring 5 is adapted to the outer diameter of the cylinder 7. Four pin holes 23 are evenly distributed on the outer side of the inner hole of the support ring 5. A recessed groove 20 extending to its outer edge is opened on the upper surface of the support ring 5 outside the pin holes 23. The shape of the pin holes 23 and the recessed groove 20 is adapted to the shape of the groove-formed pin 3.

[0050] The grooved pin 3 is an L-shaped strip plate. The short side of the grooved pin 3 is inserted into the pin hole 23, and the long side is installed in the recessed groove 20 and extends out of the outer edge of the support ring 5. After the grooved pin 3 is installed on the support ring 5, the upper surface of the grooved pin 3 is flush with the upper surface of the support ring 5.

[0051] The shape of the long side of the grooved pin 3 extending to the outer edge of the support ring 5 is adapted to the shape of the blind hole 21 below the metal skeleton 7 of the rubber guide sleeve to be prepared.

[0052] The chamfered upper cavity groove 9 and the chamfered lower cavity groove 13 are adapted to the shapes of the top and bottom of the guide sleeve to be prepared, respectively.

[0053] A method for forming a rubber guide sleeve with a metal skeleton, the method being implemented based on the aforementioned forming mold for the rubber guide sleeve with a metal skeleton, includes the following steps:

[0054] Step 1: Pre-treatment of the metal skeleton:

[0055] First, clean the oil stains on the surface of the metal frame 17 with gasoline, then soak it in dilute acid for 5-12 hours to remove rust. Next, rinse the surface of the metal frame 17 with hot water at 80-90℃. After drying, apply a layer of metal-rubber adhesive to the bonding surface with the rubber. Let it stand at room temperature for 30 minutes, then apply a second layer of metal-rubber adhesive and let it stand for 2 hours before use.

[0056] Step 2: Rubber Preparation

[0057] The plasticized raw rubber for preparing the rubber guide sleeve is placed in the mixing chamber of the internal mixer. Various additives are added according to the process requirements. After all the mixture is mixed, the machine is started to mix and obtain a semi-finished compound rubber product. The semi-finished compound rubber product is taken out of the internal mixer and cooled. When the temperature of the semi-finished compound rubber product drops to below 30°C, the semi-finished compound rubber product is put into the mill again, a crosslinking agent is added, and it is mixed evenly. The mixed rubber is then discharged from the sheet and cooled to obtain a compound rubber sheet. The compound rubber sheet is then cut into the required specifications.

[0058] Step 3: Mold closing and vulcanization:

[0059] Place the lower mold 4 on the lower platen of the vulcanizing machine. Place the support ring 5 on the upper surface of the frustum 11 of the lower mold 4. Assemble the groove forming pin 3 into the recessed groove 20 of the support ring 5. The top of the long side of the groove forming pin 3 extends out of the outer edge of the support ring 5. Then, place the metal skeleton 17, which has been pretreated in step one and coated with metal-rubber adhesive, on the upper surface of the support ring 5. Place the middle mold 2 on the lower mold 4, so that the inclined surface of the frustum 11 fits against the mating inclined surface at the bottom of the middle mold 2. Put an appropriate amount of the mixed rubber sheet prepared in step two into the molding cavity. Assemble the upper mold 1 onto the lower mold 4. Control the upper platen of the vulcanizing machine to gradually descend. The upper platen applies pressure to the mold. The upper mold 1, middle mold 2, and lower mold 4 close. Set the temperature, time, and pressure according to the process requirements to carry out vulcanization molding.

[0060] Step 4: Demolding

[0061] After vulcanization is completed, the platen on the vulcanizing machine is raised, and the operator inserts a tool into the upper mold opening groove 15 to open the upper mold 1. Then the middle mold 2 is moved upward, and the formed rubber guide sleeve is moved out along with the middle mold 2. The four groove forming pins 3 stuck under the metal ring are taken out from the rubber guide sleeve and placed back into the sinking groove 20 of the support ring 5 for use in the production of the next product. After the rubber guide sleeve passes inspection, it is put into storage.

[0062] The surface roughness Ra of the molding cavity remains at .

[0063] This invention assembles an upper mold, a middle mold, and a lower mold to form a molding cavity for the guide sleeve to be prepared. This cavity is formed by a chamfered upper cavity groove, the outer wall of a cylinder, the outer wall of a support ring, a chamfered lower cavity groove, and the inner wall of a cavity hole. The front ends of four grooved molding pins assembled on the support ring extend beyond the edge of the support ring. During the vulcanization process of the film, the front ends of the grooved molding pins form grooves below the metal skeleton of the rubber guide sleeve. The metal skeleton is bonded to the side wall of the upper mold, and the support ring supports the metal skeleton, ensuring the precise positioning of the metal skeleton and preventing displacement during the vulcanization process of the film.

[0064] The above are merely preferred embodiments of the present invention. It should be noted that, for those skilled in the art, other equivalent modifications and improvements can be made based on the technical teachings provided by the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A molding die for a rubber guide sleeve with a metal skeleton, wherein a circular metal skeleton (17) is provided in the middle of the inner wall of the rubber guide sleeve to be prepared, and four blind holes (21) are evenly distributed on the inner wall below the metal skeleton (17), characterized in that: The upper mold (1), middle mold (2), and lower mold (4) are included. The upper mold (1) includes an integrally formed coaxial upper disk (6) and a cylinder (7). The outer diameter of the cylinder (7) is adapted to the inner diameter of the rubber guide sleeve to be prepared. A positioning hole (8) coaxial with the cylinder (7) is opened in the center of the cylinder (7). A chamfered upper cavity groove (9) in the shape of an annulus is opened on the lower surface of the upper disk (6). The chamfered upper cavity groove (9) is close to the connection between the cylinder (7) and the upper disk (6). The lower mold (4) includes an integrally formed coaxial lower... The disk (10), the frustum (11), and the positioning boss (12) are provided. The outer diameter of the positioning boss (12) is matched with the inner diameter of the positioning hole (8). A circular chamfered lower cavity groove (13) is provided on the upper surface of the frustum (11). The chamfered lower cavity groove (13) and the chamfered upper cavity groove (9) are vertically symmetrical. A cylindrical middle mold (2) is installed between the lower mold (4) and the upper mold (1). A cavity hole (14) is provided in the center of the middle mold (2) and is coaxial with it. The diameter of the cavity hole (14) is the same as that of the rubber to be prepared. The outer diameter of the guide sleeve is matched; when the mold is closed, the positioning boss (12) of the lower mold (4) is inserted into the positioning hole (8), and a support ring (5) is fitted on the outer wall of the positioning boss (12). Four radially arranged groove forming pins (3) are symmetrically placed on the upper surface of the support ring (5). The upper surface of the support ring (5) abuts against the lower surface of the cylinder (7). A metal skeleton (17) is installed on the lower part of the outer wall of the cylinder (7). The lower surface of the metal skeleton (17) abuts against the edge of the upper surface of the support ring (5); chamfering The outer wall of the cavity groove (9), the outer wall of the cylinder (7), the outer wall of the support ring (5), the chamfered lower cavity groove (13), and the inner wall of the cavity hole (14) form the molding cavity of the guide sleeve to be prepared; the lower side wall of the cavity hole (14) is provided with a positioning slope (16) that matches the outer wall of the frustum (11) of the lower mold (4); a circular lower glue groove (19) is provided at the connection between the positioning slope (16) and the frustum (11); and a circular upper glue groove (18) is provided at the connection between the middle mold (2) and the upper mold (1).

2. The forming mold according to claim 1, characterized in that: The upper surface of the middle mold (2) has several upper mold opening grooves (15) on its outer edge.

3. The forming mold according to claim 1 or 2, characterized in that: The frustum (11) is a two-stage stepped frustum. The upper step is a cylinder with a diameter that matches the outer diameter of the support ring and the inner diameter of the rubber guide sleeve to be prepared. The outer wall of the lower step is an inclined surface with an inclination angle of 10-15°.

4. The forming mold according to claim 3, characterized in that: The positioning inclined surface (16) is adapted to the shape of the lower frustum of the frustum (11). After the mold is closed, there is a gap between the bottom surface of the middle mold (2) and the upper surface of the lower disk (10) of the lower mold (4). This gap is the lower mold opening groove (22) when the middle mold (2) and the lower mold (4) are opened.

5. The forming mold according to claim 4, characterized in that: The support ring (5) is a circular plate. The diameter of the inner hole of the support ring (5) is adapted to the outer diameter of the positioning boss (12). The outer diameter of the support ring (5) is adapted to the outer diameter of the cylinder (7). Four pin holes (23) are evenly distributed on the outer side of the inner hole of the support ring (5). A recessed groove (20) extending to its outer edge is opened on the upper surface of the support ring (5) outside the pin hole (23). The shape of the pin hole (23) and the recessed groove (20) are adapted to the shape of the groove forming pin (3).

6. The forming mold according to claim 5, characterized in that: The grooved forming pin (3) is an L-shaped strip plate. The short side of the grooved forming pin (3) is inserted into the pin hole (23), and the long side is installed in the sink groove (20) and extends out of the outer edge of the support ring (5). After the grooved forming pin (3) is installed on the support ring (5), the upper surface of the grooved forming pin (3) is flush with the upper surface of the support ring (5).

7. The forming mold according to claim 6, characterized in that: The long side of the grooved pin (3) extending to the outer edge of the support ring (5) is adapted to the shape of the blind hole (21) below the metal skeleton (17) of the rubber guide sleeve to be prepared.

8. The forming mold according to claim 6, characterized in that: The chamfered upper cavity groove (9) and the chamfered lower cavity groove (13) are respectively adapted to the shapes of the top and bottom of the guide sleeve to be prepared.

9. A method for forming a rubber guide sleeve with a metal skeleton, the method being implemented using a forming mold for a rubber guide sleeve with a metal skeleton according to any one of claims 1 to 7, characterized in that: Includes the following steps: Step 1: Pre-treatment of the metal skeleton: First, clean the oil stains on the surface of the metal frame (17) with gasoline, then soak it in dilute acid for 5-12 hours to remove rust, then rinse the surface of the metal frame (17) with hot water at 80-90℃, and after drying, apply a layer of metal-rubber adhesive to the bonding surface with the rubber, let it stand at room temperature for 30 minutes, then apply a second layer of metal-rubber adhesive, and let it stand for 2 hours before use; Step 2, Rubber Preparation: The plasticized raw rubber for preparing the rubber guide sleeve is placed in the mixing chamber of the internal mixer. Various additives are added according to the process requirements. After all the mixture is mixed, the machine is started to mix and obtain a semi-finished compound rubber product. The semi-finished compound rubber product is taken out of the internal mixer and cooled. When the temperature of the semi-finished compound rubber product drops to below 30°C, the semi-finished compound rubber product is put into the mill again, a crosslinking agent is added, and it is mixed evenly. The mixed rubber is then discharged from the sheet and cooled to obtain a compound rubber sheet. The compound rubber sheet is then cut into the required specifications. Step 3: Mold closing and vulcanization: Place the lower mold (4) on the lower platen of the vulcanizing machine, place the support ring (5) on the upper surface of the frustum (11) of the lower mold (4), assemble the groove forming pin (3) into the recess (20) of the support ring (5), and extend the top of the long side of the groove forming pin (3) out of the outer edge of the support ring (5). Then place the metal skeleton (17) coated with metal-rubber adhesive after the pretreatment in step one on the upper surface of the support ring (5), place the middle mold (2) on the lower mold (4), so that the inclined surface of the frustum (11) fits with the positioning inclined surface (16) at the bottom of the middle mold (2), put an appropriate amount of the mixed rubber sheet prepared in step two into the molding cavity, assemble the upper mold (1) onto the lower mold (4), control the upper platen of the vulcanizing machine to gradually descend, the upper platen applies pressure to the mold, and the upper mold (1), middle mold (2) and lower mold (4) close the mold; set the temperature, time and pressure according to the process requirements, and carry out vulcanization molding. Step 4: Demolding After vulcanization is completed, the platen on the vulcanizing machine is raised. The operator inserts the tool into the upper mold opening groove (15) to open the upper mold (1), and then moves the middle mold (2) upward. The formed rubber guide sleeve is moved out along with the middle mold (2). The four groove forming pins (3) stuck under the metal ring are taken out from the rubber guide sleeve and placed in the sinking groove (20) of the support ring (5) for use in the production of the next product. The rubber guide sleeve is put into storage after passing inspection.

10. The method for forming a rubber guide sleeve with a metal skeleton according to claim 9, characterized in that: The surface roughness Ra of the molding cavity is maintained at .

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