Molding device for silicon rubber case for cable flexible joint

Abstract

The utility model discloses a forming device and a forming method for a silicon rubber case for a cable flexible joint, belongs to the field of cable accessories, and solves the problem of poor joint quality caused by structural defects of the silicon rubber case in the prior art. In the invention, the core rod and the sleeve are coaxially arranged; a material injection nozzle communicated with the forming cavity is formed in the middle section of the sleeve; the forming cavity is a cylindrical cavity, and the wall thickness of the cylindrical middle section of the forming cavity is smaller than that of the two cylindrical ends of the forming cavity; the middle section of the core rod is provided with an annular protrusion, and the annular protrusion surrounds the length extending direction of the core rod and is coaxial with the core rod. According to the forming device and the forming method for the silicon rubber case for the cable flexible joint, the forming device is simple in structure and convenient to demould, when the silicon rubber case produced based on the forming device is applied to the cable flexible joint, the situation that a tool mould is adhered to an insulating layer can be avoided, the requirements for the appearance and supporting force of the insulating layer of the cable flexible joint are met, and the production efficiency is improved. And a corresponding insulation repair size can be reserved.

Description

Technical Field

[0001] The utility model relates to a molding device for a silicone sleeve used for a cable flexible joint, belonging to the field of cable accessories. Background Art

[0002] In recent years, with the development of the national economy, long-distance ultra-high voltage direct current transmission projects have been widely used in China. Due to the limitations of production length and transportation conditions, a single cable cannot meet the actual needs of the project, so cable joint manufacturing technology becomes particularly important. Especially for cables in special use scenarios such as submarine cables, they may need to withstand certain external forces (such as bending, stretching) and chemical effects (such as seawater corrosion). Ordinary joint structures will be more prone to cracks, and the consequences of cracks will also be easier and faster to develop further (such as water tree reactions in seawater, causing insulation breakdown).

[0003] The current mainstream technology is the "two-step method" for preparing cable flexible joints, that is, first the insulating material is filled and shaped in the injection molding device, then the molded structure is filled with the insulating material and cross-linked in the cross-linking mold, and finally the flexible joint is degassed. There are currently two methods for restoring the insulation layer of cable flexible joints. One is that the insulating material is in direct contact with the metal tooling mold, which heats up quickly and easily causes over-cross-linking of the insulating material. The other is to use a silicone sleeve to isolate the insulating material and the tooling mold. However, the existing silicone sleeve has structural defects. If the inner diameter of the silicone sleeve is too large, the two ends of the silicone sleeve cannot be tightly fixed to the cable flexible joint, and the insulating material will overflow and contact the tooling mold; if the inner diameter of the silicone sleeve is the same as that of the cable, the eccentricity problem of the insulating layer caused by its own weight cannot be repaired. Utility Model Content

[0004] The utility model provides a molding device for a silicone sleeve for a cable flexible joint. The silicone sleeve produced based on the molding device can maintain a thin middle section and thick ends. When applied to a cable flexible joint, it avoids the situation where the tooling mold and the insulation layer are adhered, meets the appearance requirements of the insulation layer of the cable flexible joint, and can reserve the corresponding insulation repair size. In addition, the silicone material has a high shrinkage force, so the surface of the insulation layer will be subjected to uniform axial internal stress during the cross-linking process, thereby improving the overall density and eccentricity of the insulation recovery area.

[0005] The technical solution adopted by the utility model is a molding device for a silicone sleeve for a cable flexible joint, comprising a sleeve and a core rod; the sleeve is hollow inside, the core rod is inserted into the sleeve, and a molding cavity is formed between the outer surface of the core rod and the inner surface of the sleeve;

[0006] The core rod is coaxially arranged with the sleeve; the middle section of the sleeve is provided with an injection nozzle connected with the molding cavity; the molding cavity is a cylindrical cavity, and the wall thickness of the cylindrical middle section of the molding cavity is smaller than the wall thickness of the cylindrical ends of the molding cavity;

[0007] The middle section of the core rod has an annular protrusion, which surrounds the length extension direction of the core rod and is coaxially arranged with the core rod.

[0008] Optimally, the molding device for the silicone sleeve for the cable flexible joint is provided with openings at both ends of the sleeve, and end caps are respectively provided at the openings at both ends of the sleeve;

[0009] The end cap is relatively fixed and sealed with the end of the sleeve and the end of the core rod.

[0010] Optimally, in the molding device for the silicone sleeve for the cable flexible joint, the two ends of the core rod respectively have connecting protrusions, and the connecting protrusions at the ends of the core rod pass through the end caps and are threadedly connected with nuts.

[0011] Optimally, the above-mentioned molding device for silicone sleeves for cable flexible joints is provided with a discharge and exhaust channel connected to the molding cavity on the end cover.

[0012] Optimized, the molding device for the silicone sleeve for cable flexible joints has openings at both ends of the sleeve and annular positioning rings are constructed at the openings at both ends of the sleeve, and the end of the core rod is inserted into the annular interior of the positioning ring and contacts with the annular inner surface of the positioning ring.

[0013] Optimally, in the molding device for the silicone sleeve for the cable flexible joint, the middle section of the core rod has a cavity inside, and the cavity inside the middle section of the core rod is arranged along the length extension direction of the core rod.

[0014] Optimally, in the molding device for the silicone sleeve for the cable flexible joint, the core rod comprises a middle cylindrical section and two end sections;

[0015] The middle cylindrical section is a cylinder with openings at both ends; the two end sections are respectively located at the openings at both ends of the middle cylindrical section; the middle cylindrical section and the two end sections surround a cavity inside the middle section of the core rod;

[0016] One end of the end section facing the middle cylindrical section has a positioning protrusion; the positioning protrusion is inserted into the end opening of the middle cylindrical section or the positioning protrusion is threadedly connected to the end opening of the middle cylindrical section.

[0017] Optimally, in the molding device for the silicone sleeve for the cable flexible joint, both ends of the annular protrusion in the middle section of the core rod have slope sections respectively.

[0018] Optimized, the above-mentioned molding device for silicone sleeves for cable flexible joints, the sleeve includes a middle cylinder and two end cylinders, the two end cylinders are respectively located at both ends of the middle cylinder and are threadedly connected to the middle cylinder.

[0019] The advantages of this application are:

[0020] By using the molding device of the present application, a silicone sleeve protective layer can be formed between the isolation tooling mold and the insulation layer, which can not only ensure that the cable flexible joint is easier to demold, but also ensure its cleanliness, meet the appearance requirements of the insulation layer of the cable flexible joint, and reserve corresponding insulation repair dimensions.

[0021] In addition, the molded silicone sleeve of the present application uses silicone material and has a very high shrinkage force. Therefore, the surface of the insulation layer will be subjected to uniform axial internal stress during the cross-linking process, thereby improving the overall density and eccentricity of the insulation recovery area, greatly improving the preparation quality of the cable flexible joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of this application. DETAILED DESCRIPTION

[0023] The technical features of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] As shown in the figure, the utility model is a molding device for a silicone sleeve for a cable flexible joint, comprising a sleeve 3 and a core rod 5. The sleeve 3 is hollow inside, the core rod 5 is inserted into the sleeve 3, and the core rod 5 and the sleeve 3 are coaxially arranged.

[0025] A molding cavity is formed between the outer surface of the core rod 5 and the inner surface of the sleeve 3. An injection nozzle 4 connected to the molding cavity is constructed in the middle section of the sleeve 3. When the silicone sleeve is molded, the injection nozzle 4 is used to inject material into the molding cavity.

[0026] The molding cavity is a cylindrical cavity. The middle section of the core rod 5 has an annular protrusion 501, which surrounds the length extension direction of the core rod 5 and is coaxially arranged with the core rod 5. The setting of the annular protrusion 501 makes the wall thickness of the cylindrical middle section of the molding cavity smaller than the wall thickness of the cylindrical ends of the molding cavity, so that the silicone sleeve is formed in a form of thin middle section and thick ends after molding. When the inner diameters of the two ends of the silicone sleeve are the same as those of the cable, it can be made to fit tightly against the cable flexible joint to complete the sealing and fixation of the two. The diameter of the insulating layer in the middle of the silicone sleeve will be larger than the diameter of the cable, so the eccentricity problem of the insulating layer caused by its own weight can be repaired later.

[0027] The two ends of the sleeve 3 are open, and end caps 2 are respectively provided at the two end openings of the sleeve 3. The end caps 2 are relatively fixed and sealed with the ends of the sleeve 3 and the end of the core rod 5. In order to release the gas in the molding cavity when injecting the silicone material and prevent bubbles and impurities from appearing in the insulating layer, the end caps 2 are provided with discharge and exhaust channels 201 connected to the molding cavity.

[0028] Both ends of the sleeve 3 are open and an annular positioning ring 301 is constructed at the openings at both ends of the sleeve 3 . The end of the mandrel 5 is inserted into the annular interior of the positioning ring 301 and contacts with the annular inner surface of the positioning ring 301 .

[0029] Both ends of the core rod 5 are provided with connecting protrusions respectively. The connecting protrusions at the ends of the core rod 5 pass through the end cover 2 and are threadedly connected with nuts.

[0030] In order to reduce the weight of the entire device, facilitate operation and control manufacturing costs, the middle section of the mandrel 5 has a cavity inside, and the cavity inside the middle section of the mandrel 5 is arranged along the length extension direction of the mandrel 5.

[0031] The mandrel 5 comprises a middle cylindrical section 502 and two end sections 503. The middle cylindrical section 502 is a cylinder with openings at both ends. The two end sections 503 are respectively located at the openings at both ends of the middle cylindrical section 502. The middle cylindrical section 502 and the two end sections 503 enclose a cavity inside the middle section of the mandrel 5. One end of the end section 503 facing the middle cylindrical section 502 has a positioning protrusion 504. The positioning protrusion 504 is inserted into the end opening of the middle cylindrical section 502 or the positioning protrusion 504 is threadedly connected to the end opening of the middle cylindrical section 502.

[0032] Both ends of the annular protrusion 501 in the middle of the core rod 5 have slope sections 505 respectively.

[0033] The sleeve 3 includes a middle cylinder 302 and two end cylinders 303, and the two end cylinders 303 are respectively located at both ends of the middle cylinder 302 and are threadedly connected to the middle cylinder 302. The sleeve 3 and the core rod 5 are arranged in a multi-section connection form, which is convenient for demoulding after the silicone sleeve is formed.

[0034] A method for molding silicone rubber for a flexible cable joint uses the molding device for the silicone rubber sleeve for a flexible cable joint and comprises the following steps.

[0035] 1. Preparation before production:

[0036] 1. Before production, clean the production site, clean the dust and impurities on the equipment surface, and clean the mold surface and inner cavity.

[0037] 2. According to the production plan of the day, go to the mold room to collect the mold, and carefully check whether the model and specifications of the mold correspond to the production task, and check whether the mold cavity inside the mold is damaged. Only after the inspection is correct can the mold be transferred to the production workshop.

[0038] 3. Prepare the tools (pliers, wrenches, etc.), release agents, etc. needed for the day's production according to production needs, and clean them to ensure cleanliness. Finally, check whether the overall environmental purity and compressed air pressure meet production requirements. If there are any problems, they should be dealt with in a timely manner.

[0039] 2. Production

[0040] 1. When installing the mold, pay attention to the concentricity of the mold core and the mold sleeve. Care should be taken to avoid damaging the mold due to the non-concentricity of the mold core and the mold sleeve. When tightening the screws, pay attention to symmetrical force.

[0041] 2. After checking the mold, clean it with anhydrous ethanol, apply release agent, and install the mold.

[0042] 3. Clean and install the injection nozzle, connect the power and gas source of the injection equipment, start the injection equipment, and record the readings of the scales on components A and B (injection process A and B components 1:1, ensure that the descending scales of components A and B are consistent), the temperature and humidity of the workshop on that day, the temperature and time when injection starts, and the injection pressure.

[0043] 4. During the glue injection process, pay attention to whether there is glue overflowing from the glue overflow port. After the glue overflows, turn off the glue injection machine and record the scale readings of components A and B, the injection stop temperature and stop time. Open the glue injection quick connector and wrap it to prevent contamination.

[0044] 5. Push the mold into the oven, set the oven temperature controller to the molding temperature, start the oven, and record the current time and the starting temperature of the temperature rise. Record the time after the vulcanization temperature is reached, stop heating after the vulcanization time is reached, and record the time.

[0045] Note: 1. Before heating, check whether the glue overflow port is unobstructed, and only inject glue after confirming that it is correct.

[0046] 2. Whether the product needs to be kept warm, as well as the temperature and time of the insulation, should be determined based on actual production and the viscosity of the raw materials.

[0047] 3. Demolding

[0048] 1. After the oven is closed, the mold cools naturally to room temperature.

[0049] 2. Install the mold on the demoulding tooling, turn on the oil pump of the molding equipment, and jog the oil pump to separate the mold. After the mold core and the mold sleeve are separated, first completely separate the flash of the product from the original product, and then lower the mold core to avoid damaging the product.

[0050] 3. Use an air gun to blow air into the gap between the product and the mold, wear protective gloves (the gloves must be clean), and separate the product from the mold.

[0051] 4. Package the product, fill out the product transfer card, and place it in the designated location.

[0052] 4. Continuous production

[0053] 1. During continuous production, after the product is ejected, clean the mold and close the mold for standby use.

[0054] 2. Repeat steps 2 and 3.

[0055] 5. Post-production processing

[0056] 1. After production, the mold should be disassembled and cleaned. If it is not used for a long time, the inner mold cavity should be coated with silicone grease and then returned to the mold room.

[0057] 2. If the mold is to be used again the next day, the mold should be closed. Repeat steps 1, 2, and 3 for production the next day.

[0058] Process parameter table

[0059] Product vulcanization temperature ℃ Product vulcanization time min Injection pressure Demolding temperature 150 90 180pa normal temperature

[0060] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A molding device for a silicone sleeve for a cable flexible joint, comprising a sleeve (3) and a core rod (5); the sleeve (3) is hollow inside, the core rod (5) is inserted into the sleeve (3) and a molding cavity is formed between the outer surface of the core rod (5) and the inner surface of the sleeve (3); the characteristics are: The core rod (5) and the sleeve (3) are coaxially arranged; the middle section of the sleeve (3) is provided with an injection nozzle (4) connected to the molding cavity; the molding cavity is a cylindrical cavity, and the wall thickness of the cylindrical middle section of the molding cavity is smaller than the wall thickness of the cylindrical ends of the molding cavity; The middle section of the core rod (5) has an annular protrusion (501), which surrounds the length extension direction of the core rod (5) and is coaxially arranged with the core rod (5).

2. The molding device for the silicone sleeve for cable flexible joint according to claim 1 is characterized in that: The sleeve (3) is provided with openings at both ends, and end covers (2) are respectively provided at the openings at both ends of the sleeve (3); The end cover (2), the end of the sleeve (3) and the end of the core rod (5) are relatively fixed and sealed.

3. The molding device for the silicone sleeve for cable flexible joint according to claim 2 is characterized in that: Both ends of the core rod (5) are provided with connection protrusions respectively, and the connection protrusions at the ends of the core rod (5) pass through the end cover (2) and are threadedly connected to nuts.

4. The molding device for the silicone sleeve for cable flexible joint according to claim 2 is characterized in that: The end cover (2) is provided with a discharge and exhaust channel (201) which is in communication with the molding cavity.

5. The molding device for the silicone sleeve for cable flexible joint according to claim 1, characterized in that: The sleeve (3) is provided with openings at both ends and an annular positioning ring (301) is constructed at the openings at both ends of the sleeve (3). The end of the mandrel (5) is inserted into the annular interior of the positioning ring (301) and contacts the annular inner surface of the positioning ring (301).

6. The molding device for the silicone sleeve for cable flexible joint according to claim 1, characterized in that: The middle section of the mandrel (5) has a cavity inside, and the cavity inside the middle section of the mandrel (5) is arranged along the length extension direction of the mandrel (5).

7. The molding device for the silicone sleeve for the cable flexible joint according to claim 6, characterized in that: The mandrel (5) comprises a middle cylindrical section (502) and two end sections (503); The middle cylindrical section (502) is a cylinder with openings at both ends; the two end sections (503) are respectively located at the openings at both ends of the middle cylindrical section (502); the middle cylindrical section (502) and the two end sections (503) form a cavity inside the middle section of the core rod (5); The end section (503) has a positioning protrusion (504) at one end facing the middle cylindrical section (502); the positioning protrusion (504) is inserted into the end opening of the middle cylindrical section (502) or the positioning protrusion (504) is threadedly connected to the end opening of the middle cylindrical section (502).

8. The molding device for the silicone sleeve for cable flexible joint according to claim 1, characterized in that: Both ends of the annular protrusion (501) in the middle section of the core rod (5) are respectively provided with a slope section (505).

9. The molding device for the silicone sleeve for cable flexible joint according to claim 1, characterized in that: The sleeve (3) comprises an intermediate cylinder (302) and two end cylinders (303), wherein the two end cylinders (303) are respectively located at two ends of the intermediate cylinder (302) and are threadedly connected to the intermediate cylinder (302).

Images