A manufacturing device and a manufacturing method of a positioning lug integrated forming gas cylinder

Abstract

The present application relates to a kind of positioning ear piece integrated forming gas cylinder manufacturing device and preparation method, belong to fiber composite material design and manufacturing field, gas nozzle protection joint threaded hole connecting core mould positioning shaft, front joint shaft threaded hole and gas nozzle protection joint threaded connection, chuck fixed joint shaft of front joint shaft and winding machine rotating chuck connection fixed.Winding machine passes through front and rear chuck and keeps the center line of front joint shaft-gas nozzle protection joint-core mould positioning shaft-rear joint-rear joint shaft consistent with horizontal height, and the rotation of transmission winding machine, cooperate with the Y direction movement of winding machine trolley and the extension movement of guide wire mouth to realize stable geodesic line winding process of gas cylinder.The gas cylinder realizes the winding forming of gas cylinder on rubber lining, realizes the positioning of ear piece and ensures the continuity of fiber.The structure design of water-soluble mould is flexible, forming is fast and convenient, and the cost is low, especially the advantage of development cycle is more obvious when large size.

Description

Technical Field

[0001] This invention belongs to the field of fiber composite material product design and manufacturing, and in particular relates to a manufacturing device and preparation method for an integrated positioning lug gas cylinder. Background Technology

[0002] Fiber composite gas cylinders are increasingly used across various industries due to their excellent properties of being lightweight, high-strength, and corrosion-resistant. With the development of rail transportation, new energy, and automobiles, there are increasing demands on gas cylinders for storing compressed gases to improve energy storage and achieve optimal energy efficiency. Lightweight, high-strength fiber composite gas cylinders have emerged to meet these needs. Fiber composite gas cylinders are formed by winding a liner with a certain strength. Whether cylindrical, spherical, or annular, they are all structures of revolution. To secure the cylinder to equipment, lugs are often designed at fixed positions on the cylinder to ensure safe and stable assembly during use. As an energy storage structure, especially high-pressure cylinders, gas cylinders have strict requirements for safety, high-pressure cycle life, and weight. While fiber composites possess excellent lightweight and high-strength properties, their material characteristics cannot meet the requirements for high-precision dimensional assembly. Furthermore, products made by continuous fiber winding require ensuring fiber continuity to achieve optimal fiber performance and pressure resistance. This presents design requirements for fiber composite gas cylinders to ensure fiber continuity and integrity, and to incorporate lugs for precise assembly. Summary of the Invention

[0003] In view of this, the present invention aims to provide a manufacturing apparatus and preparation method for an integrated positioning lug gas cylinder.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing an integrated positioning lug molded gas cylinder, wherein the integrated positioning lug molded gas cylinder includes an inner liner and a fiber composite material structural layer, with the inner liner outside the water-soluble mold, and the fiber composite material structural layer outside the inner liner. A winding machine uses front and rear chucks to keep the center lines of the front connecting shaft, the gas nozzle protective connector, the front connector, the core mold positioning shaft, the rear connector, and the rear connecting shaft at the same horizontal height, and drives the rotation of the winding machine. Combined with the Y-axis movement of the winding machine carriage and the extension and retraction movement of the guide nozzle, a stable geodesic winding process is achieved for the gas cylinder. After winding to the lug installation size, the lug installation fixture is installed, the lug installation position is adjusted to achieve the positioning and embedding process of the lug, the lug position and gas cylinder size are calibrated, molding is completed, the front and rear connecting shafts are disassembled, and curing is performed. After curing, the gas nozzle protective connector and the core mold positioning shaft are disassembled, water is injected to melt the water-soluble mold, the inner cavity is cleaned, and the manufacturing of the integrated positioning lug molded rubber inner liner gas cylinder is completed.

[0005] Furthermore, the specific steps include:

[0006] (1) Use masking tape to completely cover the air nozzle thread of the front connector, and insert the core mold positioning shaft into the air nozzle hole of the front connector and the bottom plane of the water-soluble mold and the rear connector in sequence to form a molded inner liner.

[0007] (2) Apply silicone grease to the threaded hole and end face of the air nozzle protection connector. Screw the threaded hole of the air nozzle protection connector into the core mold positioning shaft of the molding inner liner. Tighten the screws on the hexagonal mounting surface with a torque wrench to complete the fastening connection between the air nozzle protection connector and the molding inner liner device. After applying silicone grease to the threaded hole of the front connecting shaft, screw in the air nozzle protection connector bolt. Tighten until the positioning surface of the air nozzle protection connector-front shaft and the end face of the front connecting shaft are tightly fitted. Adjust the clamping distance of the winding machine. Insert the positioning ring from one end of the chuck fixing shaft into the front connecting shaft until it reaches the positioning ring stop surface. Screw the fastening screws into the threaded holes of the first and second fastening screws to fix the positioning ring. The chuck is fixed to the shaft and the winding machine rotating chuck. The positioning surface of the front shaft and the end face of the winding machine rotating chuck are mated and aligned. The center hole of the rear shaft and the center of the winding machine tail are mated and fixed. Silicone grease is applied to the center hole of the rear connector. The rear chuck is moved by rotating the handwheel of the rear chuck of the winding machine to move it closer to the rear connector until the center of the rear shaft is aligned with the center hole of the rear connector. The combination and installation of the winding machine and the forming fixture are completed. The center lines of the front and rear chucks of the winding machine are aligned. Through clamping and positioning, the center lines of the front shaft, the gas nozzle protective connector, the core mold positioning shaft, the inner liner, the rear connector, and the rear shaft in the gas cylinder forming device clamped between the front and rear chucks are kept at the same horizontal height.

[0008] (3) After the gas cylinder forming device is connected and fixed, start the winding machine to rotate. Use a cotton cloth soaked in ethyl acetate to clean the outer surface of the rubber inner liner. After air drying, use a brush to apply epoxy resin adhesive for winding evenly to the outer surface of the inner liner. Adjust the fiber tension, select the gas cylinder winding program, and start the program. The winding machine is driven by the winding machine chuck, and the Y-axis movement of the winding machine carriage and the extension and retraction movement of the guide nozzle are used to achieve stable winding of the gas cylinder. In order to ensure the strength and performance requirements of the gas cylinder and achieve optimal design, The winding process is carried out sequentially according to the layer design: 90°1 / 90°2 / 20°1 / 90°4 / 15°1 / 90°2 / 11°1 / 90°2 / 13°1 / 90°4. The longitudinal process starts from the root of the front joint and wraps to the root of the rear joint, embedding the joint stop pin in the end cap section. The circumferential process reciprocates the winding of the column section between the end caps. The process is carried out sequentially according to the program to complete the formation of the gas cylinder structure layer. The installation dimensions of the lugs are measured and calibrated. After the dimensional requirements are met, the lugs are integrally formed.

[0009] (4) After winding to the ear piece installation size, use a cotton cloth dipped in ethyl acetate to thoroughly wipe and clean the ear piece, and evenly apply a layer of 0.Apply a 1mm thick layer of epoxy adhesive for later use. Continue running the 9002 winding program on the gas cylinder column section. After winding the yarn to near the ear mounting position, pause the winding program and adjust the gas cylinder position so that the ear mounting positioning groove on the front connecting shaft is facing upwards. Loosen the fastening screws of the positioning ring and install the ear mounting fixture. The rear positioning arc of the ear fixture mates with the rear connecting shaft. Install the front positioning surface of the ear fixture into the first ear mounting positioning groove on the front connecting shaft. Insert the ear fixture positioning connector into the positioning ring and adjust the position of the positioning ring so that the distance between the ear positioning surface and the end face of the threaded hole of the gas nozzle protective connector meets the ear installation size requirements. Tighten the fastening screws of the positioning ring to fix the ear mounting fixture. Place the arc-shaped surface of the ear flange onto the gas cylinder mounting plate. Within the range of ear plate installation positions, adjust the ear plate installation position so that the ear plate installation alignment line on the ear plate rib and the installation line on the ear plate positioning surface of the ear plate installation fixture are aligned. Press and fix the ear plate, loosen the fastening screw of the positioning ring, and move the ear plate installation fixture along the ear plate installation positioning groove of the front connecting shaft until the positioning joint is completely out of the positioning ring. Remove the ear plate installation fixture, release the pause, and continue winding, allowing the fiber yarn to smoothly transition and wind onto the ear plate. The fiber yarn is then fixed to the ear plate by the evenly distributed embedded positioning teeth. When the gas cylinder rotates to the position where the ear plate installation positioning groove is facing upward, install the ear plate installation fixture. The rear positioning arc of the ear plate fixture mates with the rear connecting shaft, and the front positioning surface of the ear plate fixture is installed into the ear plate installation positioning groove of the front connecting shaft. Insert the positioning connector into the positioning ring, adjust the position of the positioning ring so that the distance between the ear plate positioning surface and the end face of the threaded hole of the air nozzle protective connector meets the installation size requirements of the ear plate, tighten the fastening screw of the positioning ring, fix the ear plate installation fixture, place the arc-shaped surface of the ear plate flange into the position range of the air cylinder installation ear plate, adjust the ear plate installation position so that the installation alignment mark of the ear plate rib is aligned with the installation mark on the ear plate positioning surface of the ear plate installation fixture, press and fix the ear plate, loosen the fastening screw of the positioning ring, move the ear plate installation fixture along the ear plate installation positioning groove of the front connecting shaft until the positioning connector is completely removed from the positioning ring, remove the ear plate installation fixture, release the pause, and continue winding so that the fiber yarn smoothly transitions to the top of the ear plate and is evenly distributed. The embedded positioning teeth fix the fiber yarn onto the ear piece. Repeat the ear piece positioning and installation operation described above. When there is a deviation between the ear piece installation alignment marks on the ear piece rib and the installation marks on the ear piece positioning surface of the ear piece installation fixture, adjust the ear piece position using the lubricating effect of the adhesive until the marks are aligned. Continue winding. When the yarn is wound close to the ear piece rib surface, apply external force to the fiber with a scraper. Using the center line of the ear piece rib as a reference point, place the fiber yarn onto the flanges on both sides of the ear piece rib. After the fiber yarn covers the ear piece flanges, perform another ear piece installation position calibration and continue winding. Run the ear piece reinforcement winding program 90°6 within the flange area. After ear piece reinforcement is completed, continue with the column segment 90°2 to complete the gas cylinder forming.

[0010] (5) Loosen the tail chuck of the winding machine, remove the rear connecting shaft, use a torque wrench to fix the hexagonal mounting surface, start the winding machine to rotate slowly, and use the reverse force between the thread direction of the front connecting shaft and the air nozzle protection joint and the rotation direction of the winding machine to remove the gas cylinder from the winding machine. Loosen the front chuck of the winding machine, remove the front connecting shaft, and perform gas cylinder curing and shaping. During curing, screw the air nozzle protection joint bolt into the rotary joint hole in the curing oven to achieve rotation curing of the gas cylinder. After curing, remove the core mold positioning shaft, remove the air nozzle protection joint, inject water into the gas cylinder through the air nozzle hole of the front joint, soak until the water-soluble mold dissolves, pour out the dissolved water-soluble mold material, rinse the inner cavity clean, and complete the manufacturing of the integrated positioning ear gas cylinder.

[0011] Furthermore, a layer of 0.2mm thick silicone grease is applied to the threaded hole and end face of the air nozzle protective connector, the threaded hole of the front connector shaft, and the center hole of the rear connector.

[0012] A method for preparing an integrated positioning lug-shaped gas cylinder includes a preparation apparatus comprising a water-soluble mold, a core mold positioning shaft, a gas nozzle protective connector, a front connecting shaft, a rear connecting shaft, lugs, and lug installation fixtures. The water-soluble mold has a cavity structure, with the core mold positioning shaft passing through it. The front end of the core mold positioning shaft extends out of the water-soluble mold and connects to the gas nozzle protective connector. The front end of the gas nozzle protective connector is connected to the front connecting shaft. The rear end of the core mold positioning shaft is inserted into the rear end of the water-soluble mold. The front end of the rear connecting shaft is abutted against the rear end of the core mold positioning shaft. The lug installation fixture is used to position and install the lugs in the axial direction, and several lugs are fixed outside the inner liner.

[0013] Furthermore, the water-soluble mold is provided with a front connector and a rear connector, respectively. The front connector and the rear connector are designed with stop pins and arc-shaped yarn take-up areas. The stop pins and arc-shaped yarn take-up areas strengthen the connection between the inner liner and the fiber composite material structural layer.

[0014] Furthermore, the air nozzle protective connector includes an air nozzle protective connector bolt, an air nozzle protective connector-front connector positioning surface, and an air nozzle protective connector threaded hole. The front end of the air nozzle protective connector body is the air nozzle protective connector bolt, the rear end is the air nozzle protective connector threaded hole, and the air nozzle protective connector-front connector positioning surface is provided in the middle. The air nozzle protective connector threaded hole is connected to the front end of the core mold positioning shaft to provide thread protection and protection for the front connector and its air nozzle, and to realize the rotation and curing of the gas cylinder.

[0015] Furthermore, the front connecting shaft is connected to the winding machine chuck. The front connecting shaft is designed with two or more lug tooling positioning slots, a front connecting shaft threaded hole, a positioning ring stop surface, and a chuck fixing connecting shaft. The front end of the front connecting shaft body is provided with a chuck fixing connecting shaft, which is connected and fixed to the front chuck of the winding machine. The rear end of the front connecting shaft body is provided with a front connecting shaft threaded hole, which is bolted to the air nozzle protective connector. The movement of the winding machine is transmitted through the front connecting shaft.

[0016] Furthermore, a positioning ring is provided on the front connecting shaft, and the positioning ring is locked onto the positioning ring stop surface through the threaded hole of the fastening screw.

[0017] Furthermore, the front end of the rear shaft body is provided with a rear shaft tip, and the rear end is provided with a rear shaft tip hole. The rear shaft tip hole is connected to the tip of the rear chuck of the winding machine, and the rear shaft tip is connected to the tip hole of the rear connector.

[0018] Furthermore, the lug mounting fixture includes a rear positioning arc, a positioning connector, a front positioning surface, and a positioning surface. The rear positioning arc mates with the rear connecting shaft. The front positioning surface is installed into the lug mounting positioning groove of the front connecting shaft. The positioning connector is inserted into the positioning ring. By adjusting the position of the positioning ring, the lug mounting alignment line on the lug rib and the mounting line on the lug positioning surface of the lug mounting fixture are aligned, thus determining the lug mounting position.

[0019] Compared with the prior art, the beneficial effects of the manufacturing apparatus and preparation method for an integrated positioning ear gas cylinder described in this invention are:

[0020] (1) The manufacturing device for the integrated positioning ear piece of the gas cylinder described in this invention realizes both the winding and forming of the gas cylinder on the rubber liner and the positioning and embedding of the ear piece, thus ensuring the continuity and integrity of the fiber.

[0021] (2) The water-soluble mold described in this invention has a flexible structural design, quick and convenient molding, and low cost. Its advantages in the development cycle are even more obvious when the size is large.

[0022] (3) The ear piece installation fixture described in this invention can be flexibly designed according to the shape and installation position of the ear piece, saving tooling costs, being easy to process, and having a high utilization rate.

[0023] (4) The manufacturing device for the integrated positioning ear molded gas cylinder described in this invention has a short development cycle, stable molding, can be molded in one step, convenient tooling, realizes stable molding of rubber inner liner, long service life under high pressure cycle, corrosion resistance, and can be used to manufacture cylindrical, spherical and annular gas cylinders of various structural forms, with strong design flexibility.

[0024] (5) The present invention uses water-soluble materials that can be recycled and reused, which is inexpensive, realizes the product design, improves the product performance, and is easy to operate and efficient in production and manufacturing, with significant cost advantages. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 This is a cross-sectional view of the manufacturing apparatus for an integrated positioning lug gas cylinder according to the present invention.

[0027] Figure 2 This is a cross-sectional view of the water-soluble mold-metal connector inner liner-core mold positioning shaft of the manufacturing device for an integrated positioning ear gas cylinder according to the present invention.

[0028] Figure 3 This is a cross-sectional view of the nozzle protection connector of the manufacturing device for an integrated positioning ear gas cylinder according to the present invention.

[0029] Figure 4 This is a left view of the nozzle protection connector of the manufacturing device for an integrated positioning ear gas cylinder according to the present invention.

[0030] Figure 5 This is a schematic diagram of the front shaft of a manufacturing device for an integrated positioning lug gas cylinder according to the present invention.

[0031] Figure 6 This is a schematic diagram of the left cross-section of the front connecting shaft of the manufacturing device for an integrated positioning ear gas cylinder according to the present invention.

[0032] Figure 7 This is a cross-sectional view of the positioning ring of the manufacturing device for an integrated positioning lug gas cylinder according to the present invention.

[0033] Figure 8 This is a schematic diagram of the rear shaft of a manufacturing device for an integrated positioning lug gas cylinder according to the present invention.

[0034] Figure 9 This is a schematic diagram of the ear piece in the manufacturing device for an integrated positioning ear piece of a gas cylinder according to the present invention;

[0035] Figure 10 This is a cross-sectional view of the ear piece AA of the manufacturing device for an integrated positioning ear piece of a gas cylinder according to the present invention.

[0036] Figure 11This is a schematic diagram of the ear piece installation fixture of the manufacturing device for an integrated positioning ear piece gas cylinder according to the present invention;

[0037] Figure 12 This is a side view of the ear piece mounting fixture of the manufacturing apparatus for an integrated positioning ear piece gas cylinder according to the present invention;

[0038] Figure 13 This is a cross-sectional view of the integrated positioning lug gas cylinder manufacturing apparatus and method according to the present invention.

[0039] Among them, 1-front connector, 2-rear connector, 3-ear, 4-inner liner, 5-fiber composite material structural layer, 6-ear reinforcement layer, 7-water-soluble mold, 8-core mold positioning shaft, 9-air nozzle thread, 10-air nozzle protective connector, 11-front connecting shaft, 12-positioning ring, 13-rear connecting shaft, 14-ear mounting fixture, 15-ear fixture positioning groove No. 1, 16-ear fixture positioning groove No. 2, 17-ear mounting alignment mark, 18-front connecting shaft threaded hole, 19-positioning ring stop surface, 20-chuck fixing connecting shaft, 21-fastening screw threaded hole No. 1, 22-fastening screw threaded hole No. 2. 23-Air nozzle protective connector bolt, 24-Air nozzle protective connector-front shaft positioning surface, 25-Air nozzle protective connector threaded hole, 26-Hexagonal mounting surface, 27-Rear shaft center point, 28-Rear shaft center hole, 29-Ear tooling rear positioning arc, 30-Ear tooling positioning connector, 31-Ear tooling front positioning surface, 32-Ear positioning surface, 33-Front shaft positioning surface, 34-Ear embedded positioning teeth, 35-Ear flange arc-shaped mating surface, 36-No. 1 stop pin, 37-No. 2 stop pin, 38-No. 1 arc-shaped yarn take-up area, 39-No. 2 arc-shaped yarn take-up area, 40-Front connector air nozzle hole. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0041] See Figure 1-13This embodiment describes a method for preparing an integrated positioning lug-molded gas cylinder. The integrated positioning lug-molded gas cylinder includes an inner liner 4 and a fiber composite material structural layer 5. The inner liner 4 is surrounded by a water-soluble mold 7, and the inner liner 4 is surrounded by a fiber composite material structural layer 5. A winding machine uses front and rear chucks to keep the center lines of the front connecting shaft 11, the gas nozzle protective connector 10, the front connector 1, the core mold positioning shaft 8, the rear connector 2, and the rear connecting shaft 13 at the same horizontal height, and drives the rotation of the winding machine. Combined with the Y-axis movement of the winding machine carriage and the extension and retraction movement of the guide nozzle, a stable geodesic winding process is achieved for the gas cylinder. After winding to the lug installation size, the lug installation fixture is installed, the lug installation position is adjusted, and the positioning and embedding process of the lug is realized. The lug position and gas cylinder size are calibrated to complete the molding. The front connecting shaft 11 and the rear connecting shaft 13 are then removed, and the cylinder is cured. After curing, the gas nozzle protective connector 10 and the core mold positioning shaft 8 are removed, water is injected to melt the water-soluble mold 7, and the inner cavity is cleaned, completing the manufacturing of the integrated positioning lug-molded rubber inner liner gas cylinder.

[0042] The preparation method of the integrated positioning ear gas cylinder specifically includes the following steps:

[0043] (1) Cover the air nozzle thread 9 of the front connector 1 completely with masking tape to prevent glue and other excess substances from getting on the thread during the molding process. Insert the core mold positioning shaft 8 into the air nozzle hole 40 of the front connector and the water-soluble mold 7 in sequence, and make contact with the bottom plane of the rear connector 2 to form the molding inner liner.

[0044] (2) Apply a layer of 0.2mm thick silicone grease to the threaded hole 25 of the air nozzle protective connector and its end face to prevent the threaded fit from seizing due to rotational force during the molding process, making it difficult to disassemble. At the same time, it can protect the end face of the front connector 1 from wear. Screw the threaded hole 25 of the air nozzle protective connector 10 into the core mold positioning shaft 8 of the molding inner liner. Use a torque wrench to tighten it on the hexagonal mounting surface 26 to complete the fastening connection between the air nozzle protective connector 10 and the molding inner liner device. After applying a layer of 0.2mm thick silicone grease to the threaded hole 18 of the front connecting shaft 11, screw in the air nozzle protective connector bolt 23 and tighten it until the air nozzle protective connector-front connecting shaft positioning surface 24 and the end face of the front connecting shaft 11 are tightly fitted. Adjust the clamping distance of the winding machine. Insert the positioning ring 12 from one end of the chuck fixed connecting shaft 20 into the front connecting shaft 11, up to the positioning ring stop surface 19. Avoid the positioning grooves 15 and 16 of the first and second ear pieces. Screw the fastening screws into the fastening screw thread holes 21 and 22 to secure the positioning ring 12. Connect and fix the chuck fixed connecting shaft 20 to the winding machine rotating chuck. Align the front connecting shaft positioning surface 33 with the chuck end face to ensure consistent installation position each time. Fix the rear connecting shaft tip hole 28 of the rear connecting shaft 13 to the tip of the winding machine tail end. Apply a 0.2mm thick layer of silicone grease to the tip hole of the rear connector 2. Move the rear chuck closer to the rear connector 2 by rotating the handwheel of the rear chuck of the winding machine until the tip 27 of the rear connecting shaft 13 is aligned with the tip hole of the rear connector 2. This completes the assembly and installation of the winding machine and forming fixture. The center lines of the front and rear chucks of the winding machine are aligned. Through clamping and positioning, the center lines of the gas cylinder forming device clamped between the front and rear chucks—front connecting shaft 11, gas nozzle protective connector 10, front connector 1, core mold positioning shaft 8, inner liner 4, rear connector 2, and rear connecting shaft 13—are at the same horizontal height.

[0045] (3) The mating surface structure of the ear piece 3 is designed according to the installation profile of the gas cylinder. The ear piece is integrally embedded in the gas cylinder through molding process and installation tooling. The ear piece 3 has an arc-shaped structure. The ear piece installation alignment lines 17 are engraved on both sides of the ear piece rib. If further finishing is required, machining allowance can be designed at both ends of the ear piece rib. The size of the arc surface 35 of the ear piece flange matches the outer diameter of the gas cylinder structure layer after molding. The upper part of the ear piece flange is designed with evenly distributed embedded positioning teeth 34 to strengthen the fixing of the ear piece. All edges and corners of the ear piece 3 are blunted to avoid damage to the fibers during the integral winding molding process. At the same time, it also avoids sharp angle contact between the metal parts and the fiber composite material to prevent the sharp angle contact position from becoming a weak surface when the product is under stress during use, which may cause damage or failure of the product.

[0046] (4) After the gas cylinder forming device is connected and fixed, start the winding machine to rotate. Use a cotton cloth soaked in ethyl acetate to clean the outer surface of the rubber inner liner. After air drying, use a brush to apply epoxy resin adhesive for winding evenly to the outer surface of the inner liner. Adjust the fiber tension, select the gas cylinder winding program, and start the program. The winding machine is driven by the winding machine chuck, and the Y-axis movement of the winding machine carriage and the extension and retraction movement of the guide nozzle are used to achieve stable winding of the gas cylinder. To ensure the strength and performance requirements of the gas cylinder and achieve optimal design, the winding process is performed sequentially according to the layup design: 9°1 / 90°2 / 20°1 / 90°4 / 15°1 / 90°2 / 11°1 / 90°2 / 13°1 / 90°4 (representing 9°1 layers, and so on). The longitudinal winding process starts from the root of the front connector 1 and extends to the root of the rear connector 2, embedding the connector stop pins within the end cap section. The circumferential winding process repeatedly winds the column sections between the end caps. This sequential process completes the formation of the gas cylinder structural layer (the fiber-wound portion). The lug installation dimensions are measured and calibrated; once the dimensional requirements are met, the lugs are integrally formed.

[0047] (5) After winding to the installation size of the ear piece, use a cotton cloth dipped in ethyl acetate to wipe and clean the ear piece thoroughly. Apply a 0.1mm thick layer of winding epoxy adhesive evenly to the curved surface of the ear piece and set aside for later use. Continue running the 90° 2 winding program for the gas cylinder column section. After winding the yarn to near the ear piece installation position, pause the winding program, adjust the gas cylinder position so that the position of the first ear piece tooling positioning groove 15 of the front connecting shaft 11 is upward. Loosen the fastening screw of the positioning ring 12, install the ear piece installation tooling 14, and mate the rear positioning arc 29 of the ear piece tooling with the rear connecting shaft 13. Install the front positioning surface 31 of the ear piece tooling into the first ear piece tooling positioning groove 15 of the front connecting shaft 11. Insert the ear piece tooling positioning connector 30 into the positioning ring 12, adjust the position of the positioning ring 12 so that the distance between the ear piece positioning surface 32 and the end face of the threaded hole 25 of the nozzle protection connector 10 meets the installation size requirements of the ear piece 3, tighten the fastening screw of the positioning ring 12, and fix the ear piece installation tooling 14. Place the arc-shaped surface 35 of the ear flap flange within the position range of the gas cylinder mounting ear flap. Adjust the ear flap installation position so that the installation alignment line 17 of the ear flap rib and the installation line on the ear flap positioning surface 32 of the ear flap mounting fixture 14 are aligned. Press and fix the ear flap in place. Loosen the fastening screw of the positioning ring 12. Move the ear flap mounting fixture 14 along the first ear flap fixture positioning groove 15 of the front connecting shaft 11 until the ear flap fixture positioning joint 30 is completely out of the positioning ring 12. Remove the ear flap mounting fixture 14. Release the pause and continue winding so that the fiber yarn is smoothly wound over the ear flap and fixed to the ear flap by the evenly distributed embedded positioning teeth 34. When the gas cylinder rotates to the position of the second ear piece tooling positioning groove 16 facing upward, install the ear piece installation tooling 14. The rear positioning arc 29 of the ear piece tooling and the rear connecting shaft 13 are mated and engaged. The front positioning surface 31 of the ear piece tooling is installed into the second ear piece tooling positioning groove 16 of the front connecting shaft 11. Insert the ear piece tooling positioning connector 30 into the positioning ring 12. Adjust the position of the positioning ring 12 so that the distance between the ear piece positioning surface 32 and the end face of the threaded hole 25 of the air nozzle protection connector 10 meets the installation size requirements of the ear piece 3. Then tighten the fastening screw of the positioning ring 12 to fix the ear piece installation tooling 14. Place the arc-shaped surface 35 of the ear flap flange within the position range of the gas cylinder mounting ear flap. Adjust the ear flap installation position so that the installation alignment line 17 of the ear flap rib and the installation line on the ear flap positioning surface 32 of the ear flap mounting fixture 14 are aligned. Press and fix the ear flap in place. Loosen the fastening screw of the positioning ring 12. Move the ear flap mounting fixture 14 along the second ear flap fixture positioning groove 16 of the front connecting shaft 11 until the ear flap fixture positioning connector 30 is completely out of the positioning ring 12. Remove the ear flap mounting fixture 14. Release the pause and continue winding so that the fiber yarn is smoothly wound over the ear flap and fixed to the ear flap by the evenly distributed embedded positioning teeth 34.Repeat the above-described ear piece positioning and installation operation. When there is a deviation between the installation alignment mark 17 on the ear piece rib and the installation mark on the ear piece positioning surface 32 of the ear piece installation fixture 14, adjust the position of the ear piece with the help of the lubricating effect of the adhesive until the mark is aligned, and then continue winding. When the yarn is wound close to the ear piece rib surface, apply external force to the fiber with a scraper, and place the fiber yarn on the flanges on both sides of the ear piece rib with the center line of the ear piece rib as the reference point. After the fiber yarn covers the ear piece flange, perform another ear piece installation position calibration, and then continue winding, running the ear piece reinforcement winding program 90°6 in the flange area. After the ear piece reinforcement is completed, continue to execute the column segment 90°2 to complete the forming of the gas cylinder.

[0048] (6) Loosen the tail chuck of the winding machine, remove the rear connecting shaft 13, and use a torque wrench to fix the hexagonal mounting surface 26. Start the winding machine to rotate slowly. Using the reverse force between the thread direction of the front connecting shaft 11 and the air nozzle protective connector 10 and the rotation direction of the winding machine, remove the gas cylinder from the winding machine. Loosen the front chuck of the winding machine and remove the front connecting shaft 11. Perform gas cylinder curing and shaping. During curing, screw the air nozzle protective connector bolt 23 into the rotary joint hole in the curing oven to achieve rotary curing of the gas cylinder, so as to ensure uniform temperature and uniform flow of adhesive during the curing process and prevent accumulation. After curing, remove the core mold positioning shaft 8 and remove the air nozzle protective connector 10. Inject water into the gas cylinder through the front connector air nozzle hole 40 and soak until the water-soluble mold dissolves. Pour out the dissolved water-soluble mold material, rinse the inner cavity clean, and complete the manufacturing of the integrated positioning ear gas cylinder.

[0049] The function of the lug 3 is to connect and assemble the gas cylinder and the equipment to fix the position of the gas cylinder. In this invention, the lugs are installed in two evenly spaced locations around the circumference, because the gas cylinder is a rotating structure, and it is sufficient to ensure symmetrical installation around the circumference.

[0050] The apparatus for preparing an integrated positioning ear piece gas cylinder includes a water-soluble mold 7, a core mold positioning shaft 8, a gas nozzle protective connector 10, a front connecting shaft 11, a rear connecting shaft 13, ear pieces 3, and an ear piece mounting fixture 14. The water-soluble mold 7 has a cavity structure, and the core mold positioning shaft 8 passes through the water-soluble mold 7. The core mold positioning shaft 8 extends out of the front end of the water-soluble mold 7 and connects to the gas nozzle protective connector 10. The front end of the gas nozzle protective connector 10 is connected to the front connecting shaft 11. The rear end of the core mold positioning shaft 8 is inserted into the rear end of the water-soluble mold 7. The front end pin of the rear connecting shaft 13 presses against the rear end of the core mold positioning shaft 8. The ear piece mounting fixture 14 is used to position and install the ear pieces 3 in the axial direction. Several ear pieces 3 are fixed outside the inner liner 4.

[0051] The water-soluble mold 7 is provided with a front connector 1 and a rear connector 2 at the front and rear, respectively. The front connector 1 and the rear connector 2 are designed with stop pins and arc-shaped yarn take-up areas. The stop pins and arc-shaped yarn take-up areas strengthen the connection between the inner liner and the fiber composite material structural layer 5.

[0052] The air nozzle protective connector 10 includes an air nozzle protective connector bolt 23, an air nozzle protective connector-front connector shaft positioning surface 24, and an air nozzle protective connector threaded hole 25. The front end of the air nozzle protective connector body is the air nozzle protective connector bolt 23, the rear end is the air nozzle protective connector threaded hole 25, and the air nozzle protective connector-front connector shaft positioning surface 24 is provided in the middle. The air nozzle protective connector threaded hole 25 is connected to the front end of the core mold positioning shaft 8 to provide thread protection and protection for the front connector 1 and its air nozzle, and to realize the rotation and solidification of the gas cylinder, avoiding damage to the front connector, especially the air nozzle threads, caused by multiple disassemblies during processing.

[0053] The front connecting shaft 11 is connected to the winding machine chuck. The front connecting shaft 11 is designed with two and several lug tooling positioning grooves, a front connecting shaft threaded hole 18, a positioning ring stop surface 19, and a chuck fixing connecting shaft 20. The front end of the front connecting shaft body is provided with the chuck fixing connecting shaft 20, which is connected and fixed to the front chuck of the winding machine. The rear end of the front connecting shaft body is provided with the front connecting shaft threaded hole 18, which is connected to the air nozzle protective connector bolt 23. The chuck fixing connecting shaft 20 of the front connecting shaft 11 is connected and fixed to the rotating chuck of the winding machine, and the movement of the winding machine is transmitted through the front connecting shaft 11.

[0054] A positioning ring 12 is provided on the front connecting shaft 11, and the positioning ring 12 is locked onto the positioning ring stop surface 19 through the fastening screw thread hole.

[0055] The front end of the rear shaft body is provided with a rear shaft tip 27, and the rear end is provided with a rear shaft tip hole 28. The rear shaft tip hole 28 is connected to the tip of the rear chuck of the winding machine, and the rear shaft tip 27 is connected to the tip hole of the rear connector.

[0056] The positioning ring is designed based on the distance between the ear piece mounting fixture and the ear piece, and the positioning ring stop surface satisfies the positioning of the positioning ring.

[0057] The chuck fixing shaft 20 is connected and fixed to the front chuck of the winding machine, and the front shaft positioning surface 33 is designed to ensure the consistency of the installation position each time, and to ensure the consistency and matching of the winding program and the gas cylinder position.

[0058] The lug mounting fixture 14 is used to position and install the lugs in the axial direction. It is designed with a rear positioning arc 29, a positioning connector 30, a front positioning surface 31, and a positioning surface 32. The rear positioning arc 29 mates with the rear connecting shaft 13. The front positioning surface 31 is installed into the first lug positioning groove 15 and the second lug positioning groove 16 of the front connecting shaft 11. The positioning connector 30 is inserted into the positioning ring 12. By adjusting the position of the positioning ring 12, the installation alignment line 17 of the lug rib and the installation line on the lug positioning surface of the lug mounting fixture 14 are aligned, thus determining the lug's installation position.

[0059] The ear piece positioning groove is designed according to the number and installation position of the ear pieces 3. The ear piece positioning groove is machined directly on the front connecting shaft. Figure 5 This is a partial sectional view of the ear piece tooling positioning groove. The blank area in the sectional view shows two symmetrical ear piece tooling positioning grooves.

[0060] The front and rear chucks of the winding machine clamp and position the gas cylinder forming device, ensuring that the center lines of the front connecting shaft 11, the gas nozzle protective connector 10, the front connector 1, the core mold positioning shaft 8, the inner liner 4, the rear connector 2, and the rear connecting shaft 13 are at the same horizontal level.

[0061] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A device for preparing an integrated positioning ear-shaped gas cylinder, characterized in that: The integrated positioning ear gas cylinder includes an inner liner (4) and a fiber composite material structural layer (5). The inner liner (4) is surrounded by a fiber composite material structural layer (5). The preparation device for the integrated positioning ear gas cylinder includes a water-soluble mold (7), a core mold positioning shaft (8), a gas nozzle protective connector (10), a front connecting shaft (11), a rear connecting shaft (13), several ear pieces (3), and an ear piece installation fixture (14). The water-soluble mold (7) has a cavity structure, and a core mold penetrates through the water-soluble mold (7). The positioning shaft (8) extends out of the front end of the water-soluble mold (7) and connects to the air nozzle protective connector (10). The front end of the air nozzle protective connector (10) is connected to the front connecting shaft (11). The rear end of the positioning shaft (8) is inserted into the rear end of the water-soluble mold (7). The front end of the rear connecting shaft (13) is pushed against the rear end of the positioning shaft (8). The ear piece installation fixture (14) is used to realize the positioning and installation of the ear piece (3) in the axial direction. Several ear pieces (3) are fixed outside the inner liner (4). The water-soluble mold (7) is provided with a front connector (1) and a rear connector (2) respectively. The front connector (1) and the rear connector (2) are designed with stop pins and arc-shaped yarn take-up areas. The stop pins and arc-shaped yarn take-up areas strengthen the connection between the inner liner and the fiber composite material structural layer (5). The air nozzle protection connector (10) includes an air nozzle protection connector bolt (23), an air nozzle protection connector-front connector shaft positioning surface (24), and an air nozzle protection connector threaded hole (25). The front end of the air nozzle protection connector body is the air nozzle protection connector bolt (23), the rear end is the air nozzle protection connector threaded hole (25), and the air nozzle protection connector-front connector shaft positioning surface (24) is provided in the middle. The air nozzle protection connector threaded hole (25) is connected to the front end of the core mold positioning shaft (8) to provide thread protection and protection for the front connector (1) and its air nozzle, and to realize the rotation and curing of the gas cylinder. The front connecting shaft (11) is connected to the winding machine chuck. The front connecting shaft (11) is designed with two ear tooling positioning grooves, a front connecting shaft threaded hole (18), a positioning ring stop surface (19), and a chuck fixing connecting shaft (20). The front end of the front connecting shaft body is provided with a chuck fixing connecting shaft (20), which is connected and fixed to the front chuck of the winding machine. The rear end of the front connecting shaft body is provided with a front connecting shaft threaded hole (18), which is connected to the air nozzle protective connector bolt (23) and transmits the movement of the winding machine through the front connecting shaft (11). A positioning ring (12) is provided on the front connecting shaft (11), and the positioning ring (12) is locked on the positioning ring stop surface (19) through the fastening screw thread hole; The front end of the rear shaft body is provided with a rear shaft tip (27), and the rear end is provided with a rear shaft tip hole (28). The rear shaft tip hole (28) is connected to the tip of the rear chuck of the winding machine, and the rear shaft tip (27) is connected to the tip hole of the rear connector. The ear piece mounting fixture (14) includes a rear positioning arc (29), a positioning connector (30), a front positioning surface (31), and a positioning surface (32). The rear positioning arc (29) and the rear connecting shaft (13) are mated together. The front positioning surface (31) of the ear piece is installed into the ear piece positioning groove of the front connecting shaft (11). The positioning connector (30) of the ear piece is inserted into the positioning ring (12). By adjusting the position of the positioning ring (12), the ear piece mounting alignment line (17) of the ear piece wing rib and the mounting line on the ear piece positioning surface (32) of the ear piece mounting fixture (14) are aligned, thus determining the installation position of the ear piece (3).

2. A method for preparing an integrated positioning lug gas cylinder using the apparatus for preparing an integrated positioning lug gas cylinder as described in claim 1, characterized in that: The water-soluble mold (7) is surrounded by an inner liner (4). The winding machine keeps the center lines of the front connecting shaft (11), the air nozzle protection connector (10), the front connector (1), the core mold positioning shaft (8), the rear connector (2), and the rear connecting shaft (13) at the same horizontal height through the front and rear chucks, and drives the rotation of the winding machine. In conjunction with the Y-axis movement of the winding machine carriage and the extension and retraction movement of the guide nozzle, a stable geodesic winding process is achieved for the gas cylinder. After winding to the ear plate installation size, the ear plate installation fixture is installed, the ear plate installation position is adjusted, and the ear plate positioning and embedding process is achieved. The ear plate position and the gas cylinder size are calibrated to complete the molding. The front connecting shaft (11) and the rear connecting shaft (13) are disassembled and cured. After curing, the air nozzle protection connector (10) and the core mold positioning shaft (8) are disassembled. Water is injected to melt the water-soluble mold (7), and the inner cavity is cleaned to complete the manufacturing of the integrated rubber inner liner gas cylinder with the positioning ear plate.

3. The method for preparing an integrated positioning ear gas cylinder using the apparatus for preparing an integrated positioning ear gas cylinder according to claim 2, characterized in that: Specifically, the following steps are included: (1) Use masking tape to completely cover the air nozzle thread (9) of the front connector (1), and insert the core mold positioning shaft (8) into the air nozzle hole of the front connector (1) and the bottom plane of the water-soluble mold (7) and the rear connector (2) in sequence to form a molded inner liner. (2) Apply silicone grease to the threaded hole (25) and end face of the air nozzle protection connector. Screw the threaded hole (25) of the air nozzle protection connector (10) into the core mold positioning shaft (8) of the molding inner liner. Tighten the air nozzle protection connector (10) and the molding inner liner by applying force to the hexagonal mounting surface (26) with a torque wrench. Complete the fastening connection between the air nozzle protection connector (10) and the molding inner liner device. After applying silicone grease to the threaded hole (18) of the front connecting shaft (11), screw in the air nozzle protection connector bolt (23). Tighten until the air nozzle protection connector-front connecting shaft positioning surface (24) and the end face of the front connecting shaft (11) are tightly fitted. Adjust the clamping distance of the winding machine. Insert the positioning ring (12) from one end of the chuck fixing connecting shaft (20) into the front connecting shaft (11) until it reaches the positioning ring stop surface (19). Screw the fastening screw into the threaded hole (21) of the first fastening screw and the threaded hole (22) of the second fastening screw to fix it. Positioning ring (12) connects and fixes the chuck fixing shaft (20) and the winding machine rotating chuck. The front shaft positioning surface (33) and the end face of the winding machine rotating chuck are mated and connected. The rear shaft tip hole (28) and the tail tip of the winding machine are mated and fixed. Silicon grease is applied in the rear shaft tip hole (28). The rear chuck is moved by rotating the handwheel of the rear chuck of the winding machine to make it close to the rear connector (2) until the rear shaft tip (27) of the rear shaft (13) is connected to the tip hole of the rear connector (2). The combination and installation of the winding machine and the forming fixture are completed. The center lines of the front and rear chucks of the winding machine are aligned. Through clamping and positioning, the center lines of the front shaft (11), the gas nozzle protection connector (10), the core mold positioning shaft (8), the inner liner (4), the rear connector (2), and the rear shaft (13) in the gas cylinder forming device clamped between the front and rear chucks are kept at the same horizontal height. (3) After the gas cylinder forming device is connected and fixed, start the winding machine to rotate. Use cotton cloth dipped in ethyl acetate to clean the outer surface of the rubber inner liner (4). After air drying, use a brush to dip in the epoxy resin adhesive for winding and evenly brush it onto the outer surface of the inner liner. Adjust the fiber tension, select the gas cylinder winding program, start the program to run, and drive the winding machine through the winding machine chuck to move. Combine the Y-axis movement of the winding machine carriage and the extension and retraction movement of the guide nozzle to achieve stable winding of the gas cylinder. In order to ensure the strength and performance requirements of the gas cylinder and achieve the optimal design, follow the steps in sequence. The gas cylinder structure layer is formed by winding according to the design of the layer: 9°1 / 90°2 / 20°1 / 90°4 / 15°1 / 90°2 / 11°1 / 90°2 / 13°1 / 90°4. The longitudinal program wraps from the root of the front joint (1) to the root of the rear joint (2), and the joint stop pin is embedded in the end cap section. The circumferential program reciprocates the winding of the column section between the end caps. The program is run in sequence to complete the forming of the gas cylinder structure layer. The installation dimensions of the ear piece (3) are measured and calibrated. After the dimensions meet the requirements, the ear piece (3) is formed as a whole. (4) After winding the ear piece (3) to the installation size, use a cotton cloth dipped in ethyl acetate to thoroughly wipe and clean the ear piece. Apply epoxy adhesive evenly to the curved surface of the ear piece and set aside. Continue running the 90°2 winding program of the gas cylinder column section. After winding the yarn to near the installation position of the ear piece (3), pause the winding program, adjust the position of the gas cylinder so that the position of the first ear piece tooling positioning groove (15) of the front connecting shaft (11) is upward. Loosen the fastening screw of the positioning ring (12), install the ear piece installation tooling (14), and mate the rear positioning arc (29) of the ear piece tooling with the rear connecting shaft (13). Install the front positioning surface (31) of the ear piece tooling into the first ear piece tooling positioning groove (15) of the front connecting shaft (11), and insert the ear piece tooling positioning connector (30) into the positioning ring (12). Inside, adjust the position of the positioning ring (12) so that the distance between the end face of the ear plate positioning surface (32) and the end face of the threaded hole (25) of the air nozzle protective connector (10) meets the installation size requirements of the ear plate (3). Tighten the fastening screw of the positioning ring (12) to fix the ear plate installation fixture (14). Place the ear plate flange arc-shaped matching surface (35) into the position range of the air cylinder installation ear plate. Adjust the ear plate installation position so that the ear plate installation alignment mark (17) of the ear plate rib and the installation mark on the ear plate positioning surface (32) of the ear plate installation fixture (14) are aligned. Press and fix the ear plate. Loosen the fastening screw of the positioning ring (12) and move the ear plate installation fixture (14) along the first ear plate fixture positioning groove (15) of the front connecting shaft (11). After the ear piece tooling positioning connector (30) is completely removed from the positioning ring (12), remove the ear piece installation tooling (14), release the pause, and continue winding so that the fiber yarn is smoothly wound onto the ear piece. The fiber yarn is fixed on the ear piece by the evenly distributed ear piece embedding positioning teeth (34). When the gas cylinder rotates to the position of the second ear piece tooling positioning groove (16) facing upward, install the ear piece installation tooling (14). The ear piece tooling rear positioning arc (29) and the rear connecting shaft (13) are mated and matched. The ear piece tooling front positioning surface (31) is installed into the second ear piece tooling positioning groove (16) of the front connecting shaft (11). Insert the ear piece tooling positioning connector (30) into the positioning ring (12), adjust the position of the positioning ring (12), and make the ear piece positioning surface (32) and the gas cylinder... After the distance between the end faces of the threaded hole (25) of the nozzle protective connector (10) meets the installation size requirements of the ear piece (3), tighten the fastening screw of the positioning ring (12), fix the ear piece installation fixture (14), place the arc-shaped mating surface (35) of the ear piece flange into the position range of the gas cylinder installation ear piece, adjust the installation position of the ear piece so that the ear piece installation alignment mark (17) on the ear piece rib and the installation mark on the ear piece positioning surface (32) of the ear piece installation fixture (14) are aligned, press and fix the ear piece, loosen the fastening screw of the positioning ring (12), move the ear piece installation fixture (14) along the second ear piece fixture positioning groove (16) of the front connecting shaft (11) until the ear piece fixture positioning connector (30) is completely removed from the positioning ring (12),Remove the ear piece installation fixture (14), release the pause, and continue winding to smoothly transition the fiber yarn over the ear piece. Fix the fiber yarn onto the ear piece (3) using the evenly distributed ear piece embedding positioning teeth (34). Repeat the above ear piece positioning and installation operation. When there is a deviation between the ear piece installation alignment mark (17) on the ear piece wing rib and the installation mark on the ear piece positioning surface (32) of the ear piece installation fixture (14), adjust the position of the ear piece with the help of the lubricating effect of the adhesive until the mark is reached. After alignment, continue winding. When the yarn is wound close to the ear flap rib surface, apply external force to the fiber with a scraper. Using the center line of the ear flap rib as the base point, place the fiber yarn on the flanges on both sides of the ear flap rib. After the fiber yarn covers the ear flap flange, perform another calibration of the ear flap (3) installation position, and continue winding. Run the ear flap reinforcement winding program 90°6 in the flange area. After the ear flap (3) reinforcement is completed, continue to execute the column segment 90°2 to complete the gas cylinder forming. (5) Loosen the tail chuck of the winding machine, remove the rear connecting shaft (13), fix the hexagonal mounting surface (26) with a torque wrench, start the winding machine to rotate slowly, and use the reverse force between the thread direction of the front connecting shaft (11) and the air nozzle protection connector (10) and the rotation direction of the winding machine to remove the gas cylinder from the winding machine. Loosen the front chuck of the winding machine, remove the front connecting shaft (11), and perform gas cylinder curing and shaping. During curing, screw the air nozzle protection connector bolt (23) into the rotary joint hole in the curing oven to achieve the rotation curing of the gas cylinder. After curing, remove the core mold positioning shaft (8), remove the air nozzle protection connector (10), inject water into the gas cylinder through the front connector air nozzle hole (40), soak until the water-soluble mold (7) dissolves, pour out the dissolved water-soluble mold material, rinse the inner cavity clean, and complete the manufacturing of the positioning ear integrated gas cylinder.

4. The method for preparing an integrated positioning ear gas cylinder using the apparatus for preparing an integrated positioning ear gas cylinder according to claim 3, characterized in that: Apply a layer of 0.2mm thick silicone grease to the threaded hole (25) and end face of the air nozzle protective connector, the threaded hole (18) of the front connector (11), and the top hole of the rear connector (2).

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