Mould for manufacturing large carbon urheen box

Abstract

The utility model relates to the field of carbon fiber processing and manufacturing, in particular to a mold for manufacturing a large carbon urheen box, which is reasonable in structure, simple and convenient to operate, low in cost and capable of ensuring the forming quality of carbon fiber materials. The center of the lower die plate is provided with an elliptical lower die cavity matched with the appearance of a large carbon urheen box to be formed, the lower die plate is provided with more than two threaded holes corresponding to the two sides of the lower die cavity, the end corners of the lower die plate are provided with pin holes, and the threaded holes and the pin holes do not penetrate through the lower die plate; the upper die plate is fixed on the lower die plate through pins and bolts, an upper die cavity corresponding to the lower die cavity is arranged in the center of the upper die plate, and the upper die plate is composed of a left side plate, a neck groove loose piece, a right side plate and a tail column loose piece which are arranged around the upper die cavity.

Description

Technical Field

[0001] This utility model relates to the field of carbon fiber processing and manufacturing, specifically a mold for manufacturing large carbon erhu boxes that is structurally reasonable, easy to operate, low in cost, and can guarantee the molding quality of carbon fiber materials. Background Technology

[0002] For example, patent document CN221651170U describes a large carbon fiber erhu (a two-stringed bowed instrument) box. The box body is made of carbon fiber composite material and is suitable for playing low-pitched folk music. The box body is oval-shaped, with an opening slot at the top for mounting the neck. Adjustment holes for the soundpost are located on the left and right sides of the box, and a mounting through hole for the tailpiece is located at the bottom. This product requires molding with carbon fiber material. To improve production efficiency and instrument quality, a molding die for a large carbon fiber erhu box is urgently needed.

[0003] Vacuum bag molding is a relatively simple and low-cost molding method in the field of carbon fiber molding. It involves covering the surface of the prepreg with a vacuum bag film, and by drawing a vacuum, the prepreg is brought close to the mold surface. During the curing process, the vacuum bag film can provide uniform pressure to ensure interlayer bonding of the prepreg. Summary of the Invention

[0004] To fill the gap in the existing technology, this utility model provides a mold for manufacturing large carbon erhu boxes that is structurally reasonable, easy to operate, low in cost, and can guarantee the molding quality of carbon fiber materials.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A mold for manufacturing a large carbon erhu (a two-stringed bowed instrument) box includes an upper mold plate and a lower mold plate. The lower mold plate is rectangular, with an elliptical lower cavity in its center that conforms to the shape of the large carbon erhu box to be formed. Two or more threaded holes are provided on the lower mold plate corresponding to both sides of the lower cavity. Pin holes are provided at the corners of the lower mold plate. Neither the threaded holes nor the pin holes penetrate the lower mold plate. The upper mold plate is fixed to the lower mold plate by pins and bolts. An upper mold cavity corresponding to the lower cavity is located in the center of the upper mold plate. The upper mold plate consists of a left side plate, a neck groove block, a right side plate, and a tailpiece block arranged around the upper mold cavity. The left and right side plates are symmetrically arranged on both sides of the upper mold cavity. Countersunk holes corresponding to the threaded holes are provided on the left and right side plates. Upper pin holes corresponding to the pin holes on the lower mold plate are also provided at the ends of the left and right side plates. Both the countersunk holes and the upper pin holes penetrate the upper mold plate.

[0007] The left and right side panels of this invention are respectively connected to the neck slot block at one end. In order to improve the tightness of the splicing of adjacent components, the left / right side panels and the neck slot block are provided with a matching stepped structure. That is, the left / right side panels and the neck slot block are tightly fitted together by the matching stepped structure on the adjacent side, ensuring the positioning accuracy of multiple components of the upper template.

[0008] The tail column movable block of this utility model is located in the upper mold cavity. One end of the tail column movable block is inserted into the side wall of the upper mold cavity. Furthermore, the ends of the left and right plates corresponding to the tail column movable block are respectively provided with semi-circular insertion channels. After the left and right plates are assembled, the two semi-circular insertion channels are combined to form a complete insertion channel. One end of the tail column movable block is inserted into the insertion channel. The forming part of the tail column movable block extends into the upper mold cavity. Furthermore, the forming part of the tail column movable block is cylindrical.

[0009] The area of ​​the lower template of this utility model is larger than that of the upper template. After the upper template and the lower template are fixed, the lower template is provided with an outer edge for vacuum film sealing that protrudes 20-200mm from the outer edge of the upper template, which is used to seal the vacuum film.

[0010] The upper and lower templates of this utility model are provided with four pin holes, and positioning pins are installed in the pin holes. The positioning pins are, from top to bottom, a positioning platform, a pin body, and a guide head. The diameter of the positioning platform is 2mm to 20mm larger than the diameter of the pin body. The guide head is frustoconical with a flat bottom surface. The diameter of the guide head gradually decreases from the pin body downwards. The height of the positioning platform is 2mm to 20mm. The total height of the positioning platform and the pin body is 5mm to 50mm larger than the total height of the upper template. The total height of the positioning platform, the pin body, and the guide head is not greater than the total height of the lower and upper templates.

[0011] In use, the left and right side panels, neck groove block, and tailpiece movable block, which form the upper mold template, are placed around the lower mold cavity according to their respective positions. Four locating pins are inserted into the four upper pin holes of the upper mold template until the locating pins' positioning platforms contact the surface of the upper mold template. Then, bolts are inserted into the countersunk holes of the upper mold template and tightened into the bolt holes of the lower mold template, fixing the upper and lower mold templates together. At this point, the upper and lower mold templates are fixed together, and the instrument case to be manufactured is then ready. The blank is placed into the lower and upper mold cavities according to the set layering. Auxiliary materials such as release cloth, release film, breathable felt, and vacuum film are laid in sequence. The vacuum film is sealed to the outer edge of the vacuum film sealing around the lower mold plate with sealing tape. The vacuum pipeline is connected. The mold and the material to be formed are placed into the curing oven. Vacuuming and heating are carried out at the same time. Under the action of atmospheric pressure, the vacuum film presses the blank for making the piano box into the mold cavity. After heating, the blank for making the piano box is cured to form a piano box blank. After trimming, the piano box product is obtained.

[0012] Compared with the prior art, this utility model can realize the one-time molding of a large carbon erhu box using carbon fiber material. It has a reasonable structure, is easy to demold, can ensure the molding quality of the large carbon erhu box, can realize the manufacturing of large carbon erhu boxes, meet the research and development needs of large carbon erhu, and fill the manufacturing gap of this national bass instrument. Attached image description:

[0013] Appendix Figure 1 This is a schematic diagram of the structure of a large carbon erhu box.

[0014] Appendix Figure 2 This is a schematic diagram of the structure of this utility model.

[0015] Appendix Figure 3 This is a schematic diagram of the structure of the lower template in an embodiment of this utility model.

[0016] Appendix Figure 4 This is a schematic diagram of the assembly state of the upper template in an embodiment of this utility model.

[0017] Appendix Figure 5 This is a schematic diagram of the positioning pin in an embodiment of this utility model.

[0018] Reference numerals: 1. Lower template, 2. Upper template, 3. Locating pin, 4. Bolt, 1-1. Lower mold cavity, 1-2. Threaded hole, 1-3. Pin hole, 2-1. Left side plate, 2-2. Right side plate, 2-3. Neck groove movable block, 2-4. Tail post hole movable block, 2-5. Upper mold cavity, 2-6. Countersunk hole, 2-7. Upper pin hole, 3-1. Locating platform, 3-2. Pin body, 3-3. Guide head. Detailed implementation method:

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] exist Figure 1 The image shows a large carbon fiber erhu box developed by Weihai Guangwei Precision Machinery Co., Ltd., which is a Chinese folk bass instrument. It belongs to the erhu family of instruments and its main components are made of carbon fiber composite materials.

[0021] Example:

[0022] This example provides a method for molding such as Figure 1 The mold for the large carbon erhu box shown is attached. Figure 2 As shown, this example includes a lower template 1, an upper template 2, positioning pins 3, and bolts 4;

[0023] As attached Figure 3As shown, the lower mold plate 1 in this example has a cuboid structure with a lower mold cavity 1-1 in the middle of the upper part. Its structure and size are adapted to the bottom surface of the piano box and are used to form the shape of the bottom surface of the piano box. Several threaded holes 1-2 are provided on both sides of the lower mold cavity 1-1. A pin hole 1-3 is provided on each of the four corners of the lower mold plate 1 on the outer side of the lower mold cavity 1-1. The threaded holes 1-2 and the pin holes 1-3 do not penetrate the lower mold plate 1 to ensure that the lower mold plate does not leak air.

[0024] As attached Figure 4 As shown, in this example, the upper template 2 is composed of a left side plate 2-1, a right side plate 2-2, a neck groove movable block 2-3, and a tailpiece hole movable block 2-4. These four parts surround the lower template and are located around the lower mold cavity 1-1, forming the upper mold cavity 2-5, which is used to form the upper half of the instrument box. The left side plate 2-1 and the right side plate 2-2 are each provided with several countersunk holes 2-6, which are positioned corresponding to the threaded holes 1-2 on the lower template 1, and are used to form the upper half of the instrument box.

[0025] In this example, both ends of the left side plate 2-1 and the right side plate 2-2 are provided with an upper pin hole 2-7, which corresponds to the pin hole 1-3 on the lower template 1. The pin hole 3 is used to position the upper template 2 and the lower template 1 so as to ensure that the upper mold cavity and the lower mold cavity are aligned.

[0026] In this example, the structure and dimensions of the neck groove hinge 2-3 are similar to... Figure 1 The neck mounting slot of the middle piano body is adapted to form the neck mounting slot, and the tailpiece hole movable block 2-4 has the same structure and dimensions. Figure 1 The position of the through hole for mounting the tailpiece of the violin body is appropriate;

[0027] In this example, the lower template 1 protrudes 20mm to 200mm beyond the upper template 2 on all four sides for sealing the vacuum bag film; the positioning pins 3 in this example are as shown in the attached figure. Figure 5 As shown, it is divided into three parts from top to bottom: positioning platform 3-1, pin body 3-2, and guide head 3-3. The diameter of positioning platform 3-1 is 10mm larger than that of pin body 3-2, and the diameter of guide head 3-3 gradually decreases from pin body 3-2 downwards. Positioning platform 3-1 is 5mm high. The total height of positioning platform 3-1 and pin body 3-2 is 10mm greater than the total height of upper template 2. The total height of positioning platform 3-1, pin body 3-2, and guide head 3-3 is not greater than the total height of lower template 1 and upper template 2.

[0028] In this example, during the process, the components of the upper mold template are placed around the lower mold cavity according to their respective positions. Then, four positioning pins are inserted downwards from the four pin holes of the upper mold template until the positioning platform contacts the upper mold template. Bolts are then inserted into the countersunk holes of the upper mold template and tightened into the bolt holes of the lower mold template to fix the upper and lower mold templates together. Next, the blank material for making the instrument case is placed into the lower and upper mold cavities according to the designed layering. Subsequently, auxiliary materials such as release cloth, release film, breathable felt, and vacuum film are laid out in sequence, and the vacuum film is sealed around the lower mold template with sealing tape. The vacuum pipeline is then connected. Then, it is placed in a curing oven, where vacuuming and heating are performed simultaneously. Under atmospheric pressure, the vacuum film presses the blank material for making the instrument case tightly within the mold cavity. After heating, the blank material for making the instrument case solidifies to form an instrument case blank. After finishing, the finished instrument case is obtained.

[0029] Compared with the prior art, this utility model can realize the one-time molding of a large carbon erhu box using carbon fiber material. It has a reasonable structure, is easy to demold, can ensure the molding quality of the large carbon erhu box, can realize the manufacturing of large carbon erhu boxes, meet the research and development needs of large carbon erhu, and fill the manufacturing gap of this national bass instrument.

Claims

1. A mold for manufacturing a large carbon fiber erhu box, comprising an upper mold and a lower mold, characterized in that, The lower template is rectangular, with an elliptical lower mold cavity in the center that conforms to the shape of the large carbon erhu body to be formed. Two or more threaded holes are provided on the lower template corresponding to both sides of the lower mold cavity. Pin holes are provided at the corners of the lower template. Neither the threaded holes nor the pin holes penetrate the lower template. The upper template is fixed to the lower template with pins and bolts. The upper template has an upper mold cavity in the center corresponding to the lower mold cavity. The upper template consists of a left side plate, a neck groove block, a right side plate, and a tailpiece block arranged around the upper mold cavity. The left and right side plates are symmetrically arranged on both sides of the upper mold cavity. Countersunk holes corresponding to the threaded holes are provided on the left and right side plates. Upper pin holes corresponding to the pin holes on the lower template are also provided at the ends of the left and right side plates. Both the countersunk holes and the upper pin holes penetrate the upper template.

2. The mold for manufacturing a large carbon fiber erhu box according to claim 1, characterized in that, One end of the left and right side plates is connected to the neck slot block, and the left / right side plates and the neck slot block are provided with a matching stepped structure, that is, the left / right side plates and the neck slot block are tightly fitted together through the matching stepped structures on adjacent sides.

3. The mold for manufacturing a large carbon erhu box according to claim 1, characterized in that, The tailstock movable block is located inside the upper mold cavity, and one end of the tailstock movable block is inserted into the side wall of the upper mold cavity.

4. The mold for manufacturing a large carbon erhu box according to claim 3, characterized in that, The left and right side plates are respectively provided with semi-circular insertion channels at their ends corresponding to the tail column block. After the left and right side plates are assembled, the two semi-circular insertion channels are combined to form a complete insertion channel. One end of the tail column block is inserted into the insertion channel, and the forming part of the tail column block extends into the upper mold cavity.

5. The mold for manufacturing a large carbon erhu box according to claim 4, characterized in that, The forming part of the tailstock block is cylindrical.

6. The mold for manufacturing a large carbon erhu box according to claim 1, characterized in that, The area of ​​the lower template is larger than that of the upper template. After the upper template and the lower template are fixed, the lower template has a vacuum film sealing outer edge that protrudes 20-200mm from the outer edge of the upper template.

7. The mold for manufacturing a large carbon fiber erhu box according to claim 1, characterized in that, The upper and lower templates are provided with four pin holes, and positioning pins are installed in the pin holes. The positioning pins, from top to bottom, are: a positioning platform, a pin body, and a guide head. The diameter of the positioning platform is 2mm to 20mm larger than the diameter of the pin body. The guide head is frustoconical with a flat bottom surface. The diameter of the guide head gradually decreases from the pin body downwards. The height of the positioning platform is 2mm to 20mm. The total height of the positioning platform and the pin body is 5mm to 50mm larger than the total height of the upper template. The total height of the positioning platform, the pin body, and the guide head is not greater than the total height of the lower and upper templates.

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