Sand core mold suitable for composite material shell with small diameter and large length-diameter ratio
The integrated structure of the barrel sand core and the head sand core and the water injection and dissolution demolding method solves the problem of difficult core shaft extraction in the molding of small-diameter composite shells, achieves efficient molding and lossless demolding, and is suitable for the manufacture of small-diameter and large-aspect-ratio composite shells.
Patent Information
- Application Number
- CN202422482582.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-10-10
- Estimated Expiration
- 2034-10-14
AI Technical Summary
When existing sand core molds are used to form small-diameter composite shells, the core shaft is difficult to pull out and has poor applicability, resulting in vibration and flexural deformation during the winding process, affecting the molding effect.
An integrated structure of barrel sand core and head sand core is adopted. A through hole is provided on the core shaft, and demoulding is carried out by injecting water to dissolve, avoiding direct pulling out. The head sand core and barrel sand core are dissolved into mortar under the action of hot water and flow out.
The molding applicability and demolding efficiency of small-diameter composite shells are improved, damage to the shells is avoided, and the method is suitable for large-scale industrial production.
Smart Images
Figure CN223418288U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of solid rocket engine manufacturing, in particular to a sand core mold suitable for a composite material shell with a small diameter and a large aspect ratio. Background Art
[0002] At present, composite materials are widely used in the production of solid rocket engine shells, and sand core molds are required for the production of composite material shells. Existing sand core molds mostly adopt a split-flap structure. For small-diameter composite material shells, the split-flap sand core mold further loses its advantage. The reason is that the core shaft, one of the components of the sand core mold, has to bear the weight of the entire core mold during the use of the core mold, thereby causing flexural deformation. If the flexural deformation is large and accompanied by the rotational motion of winding, the entire core mold will vibrate, making winding impossible.
[0003] Therefore, the core shaft of the sand core mold must have a certain diameter to ensure sufficient rigidity. For a small-diameter composite shell, the diameter of the sand core mold's core shaft is comparable to the required diameter for sufficient rigidity. The sand core will completely fill the space between the composite shell and the core shaft, resulting in an increased contact area and making it very difficult to remove the core shaft. In general, existing split-flap sand core molds are less suitable for small-diameter composite shells. Utility Model Content
[0004] The purpose of the utility model is to provide a sand core mold and a molding method suitable for a composite material shell with a small diameter and a large aspect ratio, so as to solve the problem that the sand core mold in the prior art has poor applicability and is difficult to pull out the core shaft when used for a composite material shell with a small diameter.
[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:
[0006] A sand core mold suitable for composite material shells with a small diameter and a large aspect ratio, comprising a barrel sand core, both ends of the barrel sand core being fixedly connected to a head sand core, a core shaft being inserted into the barrel sand core, a plurality of barrel sand core longitudinal ribs extending in the length direction being evenly distributed on the inner wall of the barrel sand core, and longitudinal ribs corresponding to the barrel sand core longitudinal ribs being arranged on the inner wall of the head sand core;
[0007] The left and right ends of the core shaft extend out of the barrel sand core. The core shaft is provided with sand consolidation grooves along the length direction, the number of which is the same as the longitudinal ribs of the barrel sand core. The specifications of the sand consolidation grooves match the longitudinal ribs of the barrel sand core. A plurality of through holes are evenly provided between two adjacent sand consolidation grooves in the middle of the core shaft along the length direction.
[0008] The core shaft is a hollow structure, and both ends of the core shaft are connected to a clamping part that can be connected to an external clamping device; the clamping part has a water injection channel in the interior thereof that is connected to the interior of the core shaft;
[0009] The end surface of the clamping portion is also connected with a connecting nozzle which is in sealed communication with the water injection channel.
[0010] The utility model also has the following features:
[0011] Furthermore, it also includes two fixing screw sleeves; the left and right ends of the core shaft extend out of the outside of the barrel sand core as connecting parts;
[0012] The fixing screw sleeve is provided with an internal thread, and the connecting portion of the core shaft is provided with an external thread matching the internal thread of the fixing screw sleeve.
[0013] A barrel segment sand core forming mold, which is used to form the barrel segment sand core, and includes a barrel segment sand core female mold and an inner liner;
[0014] The inner sleeve includes a first connecting sleeve and a plurality of cover plates. The first connecting sleeve can be fixedly sleeved on the connecting portion on the left side of the core shaft. The shape of the cover plate matches the shape of the area between two adjacent sand consolidation grooves on the core shaft. The plurality of cover plates correspond to each other and seal and cover the area between two adjacent sand consolidation grooves on the core shaft.
[0015] The barrel section sand core female mold is cylindrical, the inner diameter of the barrel section sand core female mold matches the outer diameter of the barrel section sand core, and the length of the barrel section sand core female mold is equal to the barrel section sand core;
[0016] The first connecting sleeve of the inner sleeve is sleeved with a second connecting sleeve, the barrel section sand core female mold is sleeved on the core shaft through the second connecting sleeve, and the shape of the area formed between the barrel section sand core female mold and the core shaft is the same as that of the barrel section sand core.
[0017] Furthermore, it also includes a first sealing cover plate, a first sealing pressure ring and a second sealing cover plate;
[0018] The first sealing cover plate is detachably mounted on the clamping portion on the left side of the core shaft, and is used to seal the gap between the left side of the barrel sand core female mold and the core shaft;
[0019] The first sealing pressure ring and the second sealing cover plate are detachably sleeved on the right connecting portion of the core shaft in sequence, and are used to seal the gap between the right side of the barrel section sand core female mold and the core shaft.
[0020] A head sand core forming mold, which is used to form the head sand core, and is characterized in that it includes a head sand core male mold and a head sand core female mold;
[0021] The shape of the area formed between the male mold and the female mold of the head sand core is the same as that of the head sand core.
[0022] Furthermore, it also includes a second sealing pressure ring and a third sealing cover plate;
[0023] The head sand core male mold is a cylindrical structure, and is provided with a plurality of rib grooves for forming longitudinal ribs of the head sand core; the front part of the head sand core male mold is coaxially connected with a connector;
[0024] The female mold of the end-sand core comprises a forming portion and a connecting portion, and the connector of the male mold of the end-sand core can be sealed and plugged into the connecting portion of the female mold of the end-sand core; the shape of the area formed between the inner wall of the forming portion of the female mold of the end-sand core and the male mold of the end-sand core is the same as that of the end-sand core;
[0025] The second sealing pressure ring and the third sealing cover plate are detachably mounted on the head sand core male mold from the rear of the head sand core male mold; the second sealing pressure ring is used to seal the gap between the head sand core male mold and the sealing head sand core female mold.
[0026] Compared with the prior art, the present invention has the following technical effects:
[0027] The sand core mold of the utility model is suitable for composite material shells with small diameter and large aspect ratio. In view of the stress characteristics of the core shaft during the molding of composite material shells with small diameter in the existing technology, the petal-type core mold structure is improved and an integrated structure of the core shaft, head sand core and barrel section sand core is adopted. Through structural optimization, the sand core mold can smoothly complete the winding molding of composite material shells with small diameter.
[0028] In addition, the sand core mold of the utility model, which is suitable for small-diameter, large-aspect-ratio composite material shells, has multiple through-holes on the core shaft. When demolding, it is no longer necessary to pull the sand core mold directly out of the composite material shell. Instead, hot water can be injected into the core shaft through the nozzle to gradually dissolve the head sand core and the barrel sand core, allowing the head sand core and the barrel sand core to directly dissolve into mortar and flow out of the composite material shell. This structure not only greatly improves the efficiency of demolding, but also does not cause damage to the composite material shell. It is suitable for the molding of small-diameter, large-aspect-ratio composite material shells, improves applicability and work efficiency, and is suitable for large-scale industrial use and promotion. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 This is a schematic diagram of the overall structure of a sand core mold suitable for a composite material shell with a small diameter and a large aspect ratio;
[0030] Figure 2 This is a schematic diagram of the core shaft structure in the utility model;
[0031] Figure 3 This is a schematic diagram of the longitudinal cross-section structure of the core shaft in the present utility model;
[0032] Figure 4 This is a schematic diagram of the cross-sectional structure of the core shaft in the present utility model;
[0033] Figure 5 This is a schematic diagram of the longitudinal cross-section structure of the cylindrical sand core in the utility model;
[0034] Figure 6 This is a schematic diagram of the sand core structure of the head in the utility model;
[0035] Figure 7 This is a cross-sectional structural diagram of the connection between the cylindrical sand core and the core shaft in the utility model;
[0036] Figure 8 This is a schematic diagram of the connection structure between the barrel sand core forming mold and the core shaft in the utility model;
[0037] Figure 9 This is a cross-sectional structural diagram of the connection between the barrel sand core forming mold and the core shaft in the utility model;
[0038] Figure 10 This is a schematic diagram of the cross-sectional structure of the head sand core forming mold in the utility model;
[0039] Figure 11 It is a structural schematic diagram of the head sand core male mold and the head sand core female mold in the utility model.
[0040] The meaning of each number in the figure is:
[0041] 1. Sand core of barrel section; 2. Mandrel; 3. Longitudinal ribs of sand core of barrel section; 4. Sand core of end cap; 5. Longitudinal ribs of sand core of end cap; 6. Sand consolidation groove; 7. Through hole; 8. Clamping part; 9. Water injection channel; 10. Connecting nozzle; 11. Fixing screw sleeve; 12. Female mold of sand core of barrel section; 13. Inner sleeve; 14. First sealing cover plate; 15. First sealing pressure ring; 16. Second sealing cover plate; 17. Male mold of sand core of end cap; 18. Female mold of sand core of end cap; 19. Second sealing pressure ring; 20. Third sealing cover plate; 21. Rib groove. DETAILED DESCRIPTION
[0042] It should be noted that, unless otherwise specified, all components in the present invention are components known in the prior art.
[0043] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the scope of protection of the present invention.
[0044] like Figure 1-7As shown, a sand core mold suitable for composite material shells with small diameter and large aspect ratio is characterized by comprising a barrel sand core 1, with end sand cores 4 fixedly connected to both ends of the barrel sand core 1, a core shaft 2 penetrating the barrel sand core 1, and a plurality of barrel sand core longitudinal ribs 3 extending along the length direction evenly distributed on the inner wall of the barrel sand core 1; and end sand core longitudinal ribs 5 corresponding to the barrel sand core longitudinal ribs 3 are provided on the inner wall of the end sand core 4.
[0045] The left and right ends of the core shaft 2 extend out of the barrel sand core 1. The core shaft 2 is provided with sand consolidation grooves 6 along the length direction, the number of which is the same as the longitudinal ribs 3 of the barrel sand core. The specifications of the sand consolidation grooves 6 match the longitudinal ribs 3 of the barrel sand core. A plurality of through holes 7 are evenly opened along the length direction between two adjacent sand consolidation grooves 6 in the middle of the core shaft 2.
[0046] The core shaft 2 is a hollow structure, and the two ends of the core shaft 2 are connected to a clamping portion 8 that can be connected to an external clamping device; the clamping portion 8 has a water injection channel 9 in communication with the interior of the core shaft 2;
[0047] The end surface of the clamping portion 8 is also connected to a pipe nozzle 10 that is in sealed communication with the water injection channel 9 .
[0048] The sand core mold of the utility model is suitable for composite material shells with small diameter and large aspect ratio. In view of the stress characteristics of the core shaft 2 during the molding of composite material shells with small diameter in the existing technology, the petal-type core mold structure is improved and an integrated structure of the core shaft 2, the head sand core 4 and the barrel section sand core 1 is adopted. Through structural optimization, the sand core mold can successfully complete the winding molding of composite material shells with small diameter.
[0049] Among them, the core shaft 2 is used to install and fix the barrel sand core 1. When performing the winding operation of the composite shell with a small diameter and a large aspect ratio, the external clamping device can clamp the core shaft 2 through the clamping parts 8 at both ends; when demolding, it is no longer necessary to pull the sand core mold directly out of the composite shell. It is only necessary to inject hot water into the core shaft 2 through the nozzle 10 to gradually dissolve the head sand core 4 and the barrel sand core 1, so that the head sand core 4 and the barrel sand core 1 are directly dissolved into mortar and flow out of the composite shell. This structure not only greatly increases the efficiency of demolding, but also does not cause damage to the composite shell. It is suitable for the molding of composite shells with small diameters and large aspect ratios, improves applicability and work efficiency, and is suitable for large-scale use and promotion in industry.
[0050] As a preferred solution, it also includes two fixing screw sleeves 11; the left and right ends of the core shaft 2 extending outside the barrel sand core 1 serve as the left connecting part and the right connecting part respectively;
[0051] The fixing screw sleeve 11 is provided with an internal thread, and the left and right connecting parts of the core shaft 2 are provided with external threads that match the internal thread of the fixing screw sleeve 11;
[0052] The fixing screw sleeve 11 can be screwed to the core shaft 2 to fix and compress the corresponding head sand core 4.
[0053] like Figure 8 、 9 As shown, a barrel segment sand core forming mold is used to form the above-mentioned sand core mold suitable for a small-diameter and large-aspect-ratio composite material shell, including a barrel segment sand core female mold 12 and an inner liner 13;
[0054] The inner sleeve 13 includes a first connecting sleeve and a plurality of cover plates. The first connecting sleeve can be fixedly sleeved on the left connecting portion of the core shaft 2. The shape of the cover plate matches the shape of the area between two adjacent sand consolidation grooves 6 on the core shaft 2. The plurality of cover plates correspond one to one and seal the area between two adjacent sand consolidation grooves 6 on the core shaft 2.
[0055] The barrel section sand core female mold 12 is cylindrical, the inner diameter of the barrel section sand core female mold 12 matches the outer diameter of the barrel section sand core 1, and the length of the barrel section sand core female mold 12 is equal to that of the barrel section sand core 1;
[0056] The second connecting sleeve is mounted on the first connecting sleeve of the inner sleeve 13, and the barrel section sand core female mold 12 is mounted on the core shaft 2 through the second connecting sleeve. The shape of the area formed between the barrel section sand core female mold 12 and the core shaft 2 is the same as that of the barrel section sand core 1.
[0057] As a preferred solution, it also includes a first sealing cover plate 14, a first sealing pressure ring 15 and a second sealing cover plate 16;
[0058] The first sealing cover plate 14 is detachably mounted on the clamping portion 8 on the left side of the core shaft 2 to seal the gap between the left side of the barrel sand core female mold 12 and the core shaft 2;
[0059] The first sealing pressure ring 15 and the second sealing cover plate 16 are detachably mounted on the right connecting portion of the core shaft 2 in sequence to seal the gap between the right side of the barrel sand core female mold 12 and the core shaft 2 .
[0060] This arrangement can further achieve sealing after compacting the mortar, thereby ensuring the molding effect of the barrel sand core 1.
[0061] like Figure 10 、 11 As shown, a head sand core forming mold is used to form a head sand core 4, characterized in that it includes a head sand core male mold 17 and a head sand core female mold 18;
[0062] The shape of the area formed between the head sand core male mold 17 and the head sand core female mold 18 is the same as that of the head sand core 4 .
[0063] As a preferred solution, it further includes a second sealing pressure ring 19 and a third sealing cover plate 20;
[0064] The head sand core male die 17 is a cylindrical structure, and a plurality of muscle forming grooves 21 for forming the head sand core longitudinal muscle 5 of the head sand core 4 are formed on the head sand core male die 17. The front part of the head sand core male die 17 is coaxially connected with a plug-in part;
[0065] The head sand core female die 18 comprises a forming part and a connecting part, and the plug-in part of the head sand core male die 17 can be plugged into the connecting part of the head sand core female die 18 in a sealed manner. The shape of the area formed between the inner wall of the forming part of the head sand core female die 18 and the head sand core male die 17 is the same as that of the head sand core 4.
[0066] The second sealing compression ring 19 and the third sealing cover plate 20 are detachably sleeved on the head sand core male die 17 from the rear part of the head sand core male die 17 in sequence. The second sealing compression ring 19 is used for sealing the gap between the head sand core male die 17 and the head sand core female die 18.
[0067] Such a setting can further realize sealing after the ramming of the mortar, and ensure the forming effect of the head sand core 4.
[0068] Before the completion of winding of the solid rocket engine composite material shell, the core mold 2 is first assembled. Specifically, the head sand core 4 is bonded with the integrated structure of the mandrel 2 and the barrel segment sand core 1, and is fixed by the fixing screw sleeve 11. Then, the outer dimensions of the core mold 2 are corrected by a conventional polishing or machining method to meet the requirements of the inner surface of the composite material shell. After completion, winding is performed.
[0069] After the winding of the solid rocket engine composite material shell and the completion of the curing process, hot water is injected into the mandrel 2 through the pipe nozzle 10. The hot water enters from the pipe nozzle 10, flows through the water injection channel 9, enters the inner cavity of the mandrel 2, and then flows into the space formed by the inner surface of the barrel segment sand core 1 and the head sand core 4 and the outer surface of the mandrel 2 through the uniformly distributed through holes 7 on the mandrel 2. Here, the sand core is in full contact with the hot water, the water-soluble component (adhesive) is dissolved in water, and the entire sand core gradually collapses. The collapsed part flows out from the other end of the pipe nozzle 10 with the water, or part of it remains in the space formed by the inner surface of the barrel segment sand core 1 and the outer surface of the mandrel 2. When the entire sand core is basically completely collapsed, the mandrel 2 can be removed, and the demolding of the composite material shell is completed.
Claims
1. A sand core mold suitable for a small-diameter and large-aspect-ratio composite material shell, characterized in that: The invention comprises a barrel sand core (1), both ends of the barrel sand core (1) are fixedly connected to a sealing sand core (4), a core shaft (2) is inserted into the barrel sand core (1), a plurality of barrel sand core longitudinal ribs (3) extending along the length direction are evenly distributed on the inner wall of the barrel sand core (1); and sealing sand core longitudinal ribs (5) corresponding to the barrel sand core longitudinal ribs (3) are arranged on the inner wall of the sealing sand core (4). The left and right ends of the core shaft (2) extend out of the barrel sand core (1); the core shaft (2) is provided with sand consolidation grooves (6) in the same number as the barrel sand core longitudinal ribs (3) along the length direction; the specifications of the sand consolidation grooves (6) match the barrel sand core longitudinal ribs (3); a plurality of through holes (7) are uniformly provided between two adjacent sand consolidation grooves (6) in the middle of the core shaft (2) along the length direction; The core shaft (2) is a hollow structure, and both ends of the core shaft (2) are connected to clamping parts (8) that can be connected to an external clamping device; the clamping parts (8) are provided with a water injection channel (9) in communication with the interior of the core shaft (2); The end surface of the clamping portion (8) is also connected to a pipe nozzle (10) which is in sealed communication with the water injection channel (9).
2. The sand core mold suitable for a small-diameter and large-aspect-ratio composite material shell according to claim 1, characterized in that: It also includes two fixing screw sleeves (11); the left and right ends of the core shaft (2) extend outside the barrel sand core (1) as connecting parts; The fixing screw sleeve (11) is provided with an internal thread, and the connecting portion of the core shaft (2) is provided with an external thread matching the internal thread of the fixing screw sleeve (11).
3. A barrel segment sand core forming mold, wherein the barrel segment sand core forming mold is used to form the barrel segment sand core (1) according to claim 2, characterized in that: It includes a barrel section sand core female mold (12) and an inner liner (13); The inner sleeve (13) comprises a first connecting sleeve and a plurality of cover plates, wherein the first connecting sleeve can be fixedly sleeved on the connecting portion on the left side of the core shaft (2); the shape of the cover plate matches the shape of the area between two adjacent sand consolidation grooves (6) on the core shaft (2), and the plurality of cover plates seal and cover the area between two adjacent sand consolidation grooves (6) on the core shaft (2) in a one-to-one correspondence; The barrel section sand core female mold (12) is cylindrical, the inner diameter of the barrel section sand core female mold (12) matches the outer diameter of the barrel section sand core (1), and the length of the barrel section sand core female mold (12) is equal to that of the barrel section sand core (1); The first connecting sleeve of the inner sleeve (13) is fitted with a second connecting sleeve, the barrel section sand core female mold (12) is fitted on the core shaft (2) through the second connecting sleeve, and the shape of the area formed between the barrel section sand core female mold (12) and the core shaft (2) is the same as the shape of the barrel section sand core (1).
4. The barrel section sand core forming mold according to claim 3, characterized in that: It also includes a first sealing cover plate (14), a first sealing pressure ring (15) and a second sealing cover plate (16); The first sealing cover plate (14) is detachably mounted on the clamping portion (8) on the left side of the core shaft (2) and is used to seal the gap between the left side of the barrel sand core female mold (12) and the core shaft (2); The first sealing pressure ring (15) and the second sealing cover plate (16) are detachably mounted on the right connecting portion of the core shaft (2) in sequence and are used to seal the gap between the right side of the barrel sand core female mold (12) and the core shaft (2).
5. A head sand core forming mold, the head sand core forming mold is used to form the head sand core (4) according to claim 4, characterized in that: It comprises a head sand core male mold (17) and a head sand core female mold (18); The shape of the area formed between the head sealing sand core male mold (17) and the head sealing sand core female mold (18) is the same as that of the head sealing sand core (4).
6. The head sand core forming mold according to claim 5, characterized in that: It also includes a second sealing pressure ring (19) and a third sealing cover plate (20); The head sand core male mold (17) is a cylindrical structure, and a plurality of rib grooves (21) for forming the head sand core longitudinal ribs (5) of the head sand core (4) are provided on the head sand core male mold (17); a connector is coaxially connected to the front of the head sand core male mold (17); The female mold (18) of the sealing sand core comprises a forming portion and a connecting portion, and the plug-in component of the male mold (17) of the sealing sand core can be sealed and plugged into the connecting portion of the female mold (18) of the sealing sand core; the shape of the area formed between the inner wall of the forming portion of the female mold (18) of the sealing sand core and the male mold (17) of the sealing sand core is the same as that of the sealing sand core (4); The second sealing pressure ring (19) and the third sealing cover plate (20) are detachably mounted on the head sand core male mold (17) from the rear of the head sand core male mold (17); the second sealing pressure ring (19) is used to seal the gap between the head sand core male mold (17) and the sealing head sand core female mold (18).