Core mold for forming complex heat insulation coating sleeve and forming method

Abstract

The invention discloses a core mold for forming a complex heat insulation coating sleeve and a forming method, and belongs to the technical field of solid rocket engines. The core mold comprises an end socket core mold, a barrel section core mold assembly and a connecting buckle. The barrel section core mold assembly is of a split type, a plurality of fan-shaped plate-shaped barrel section core molds are sequentially connected along the same circumferential face to form a columnar barrel structure, and every two adjacent barrel section core molds are detachably and fixedly connected through a connecting buckle. The end socket core mold is buckled to one end of the barrel section core mold assembly and detachably and fixedly connected with the barrel section core mold assembly through a connecting buckle. According to the core mold with the structure, the butt joint interface structures of all the components are unified, detachable assembly can be achieved only through a plurality of connecting buckles of the same specification, disassembly and assembly are convenient, and the mold preparation time can be effectively shortened. The coating sleeve forming method adopting the core mold is good in manufacturability and high in product quality consistency, and due to the fact that the outer surface structure of the core mold is smooth, vacuumizing tightening can be conducted through a vacuum bag, vulcanization forming is conducted in a vulcanization tank, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines, and in particular relates to a core mold for molding a complex thermal insulation covering sleeve and a molding method. Background Art

[0002] Composite propellants, as working fluid energy materials for solid rocket engines, have been widely used in various types of missile engines. Composite propellants can be directly cast against the wall of the combustion chamber shell, or they can be prefabricated in the insulation sleeve, or the insulation sleeve can be pasted on the inner surface of the combustion chamber shell before the propellant is poured. In order to meet the higher performance index requirements of solid rocket engines, fully filled solid rocket engines generally adopt the method of pasting the insulation sleeve on the inner surface of the combustion chamber shell before pouring the propellant. According to actual use requirements, the insulation sleeve of the fully filled engine needs to be formed with a thickness of 1.5mm to 3mm in a size of φ200 to φ500mm. Ventilation grooves and cable grooves of different structural forms need to be formed on the outer wall of the insulation sleeve. The structure is complex and the molding efficiency is low.

[0003] At present, the methods for forming complex thermal insulation covering sleeves are as follows: (1) According to the thickness of the thermal insulation covering sleeve, a film with a thickness slightly greater than the design requirement is made, and it is laid on the surface of the core shaft in the form of winding. After the surface of the thermal insulation covering sleeve is tightened, it is placed in a vulcanizer for vulcanization to obtain a thermal insulation covering sleeve part. The advantage of this method is that the covering sleeve parts have good consistency. The disadvantage is that the forming process requires grinding the thickness of the covering sleeve, the production efficiency is low, and covering sleeve parts with complex surfaces cannot be formed. (2) Complex-shaped covering sleeve parts are formed using a split-flap mold. The advantage is that the quality of the covering sleeve parts after forming is consistent, and covering sleeve parts with complex surfaces can be formed. The disadvantage is that in order to accurately position the mold, a variety of docking interfaces are used between the components of the split-flap mold, and the mold assembly is complex and the assembly efficiency is low. In addition, when the existing split-flap core mold is used to form a complex insulation covering sleeve, due to its structural characteristics, the core mold shape is supported by structures such as upper and lower base plates and an intermediate support ring, and a vacuum bag cannot be used to tighten the film laid on the outer surface. Therefore, a flat-plate vulcanizing machine is generally used for molding, and only one piece can be molded at a time, resulting in low production efficiency. Summary of the invention

[0004] Technical issues to be solved:

[0005] In order to avoid the shortcomings of the prior art, the present invention provides a core mold and a molding method for complex insulating covering sleeve molding, which solves the problems of the existing split mold positioning interface types, complex mold structure, low loading and unloading efficiency, and the low production efficiency of the existing insulating covering sleeve molding process.

[0006] The technical solution of the present invention is: a core mold for forming a complex heat-insulating covering sleeve, comprising a head core mold, a barrel core mold assembly and a connecting buckle;

[0007] The barrel segment core mold assembly comprises a plurality of fan-shaped plate-shaped barrel segment core molds, and the plurality of barrel segment core molds are sequentially connected along the same circumferential surface to form a barrel segment core mold assembly with a columnar barrel structure; two adjacent barrel segment core molds are detachably fixedly connected by a plurality of connecting buckles;

[0008] The main body of the end cap core mold is a bowl-shaped structure, the mouth of which is buckled to one end of the barrel section core mold assembly, and is fixedly connected to the barrel section core mold assembly through a plurality of connection buckles evenly installed around the circumference;

[0009] The connecting buckle includes a front buckle seat, a rear buckle seat, a transmission screw, a first connecting pin and a second connecting pin; the front buckle seat is provided with a slide groove, and the rear buckle seat is slidably installed in the slide groove; the transmission screw is threadedly connected to the rear buckle seat, and is used to drive the rear buckle seat to slide along the groove direction of the slide groove; the first connecting pin and the second connecting pin are respectively installed on the front buckle seat and the rear buckle seat, and are coaxially arranged opposite to each other; the distance between the rear buckle seat and the front buckle seat is adjusted by screwing the transmission screw, so as to clamp the two connected parts, at this time, the first connecting pin and the second connecting pin are correspondingly inserted into the positioning holes of the connected parts on their sides.

[0010] A further technical solution of the present invention is: the barrel section core mold assembly includes a first barrel section core mold, a second barrel section core mold, a third barrel section core mold, a fourth barrel section core mold and a fifth barrel section core mold, wherein two first barrel section core molds are provided, and the remaining barrel section core molds are each provided with one; during installation, the first barrel section core mold, the second barrel section core mold, the third barrel section core mold, another first barrel section core mold, the fourth barrel section core mold and the fifth barrel section core mold are connected in sequence along the circumferential direction, and each barrel section core mold is provided with mounting plates on both sides along the circumferential direction, and the mounting plates at the connection of two adjacent barrel section core molds are butted against each other, and a plurality of positioning holes are evenly distributed on the mounting plates for installing connecting buckles.

[0011] A further technical solution of the present invention is: an end mounting plate is provided at one end of each barrel segment core mold facing the head core mold; the end mounting plate of each barrel segment core mold forms a mounting ring of the barrel segment core mold assembly, and a plurality of positioning holes are evenly distributed circumferentially on the mounting ring; an annular connecting plate is provided at the bowl-mouth end of the head core mold, and the connecting plate is provided with positioning holes corresponding one to one with the positioning holes on the mounting ring; the mounting ring is butted against the connecting plate and fixedly connected by a connecting buckle.

[0012] A further technical solution of the present invention is: the first barrel segment core mold is provided with mounting plates perpendicular to the surface where the fan-shaped chord is located on both sides along its circumferential direction, and the connecting sides of the remaining barrel segment core molds and the first barrel segment core mold are provided with mounting plates matching the mounting plates of the first barrel segment core mold; the mounting plates at the connection between the second barrel segment core mold and the third barrel segment core mold and at the connection between the fourth barrel segment core mold and the fifth barrel segment core mold are all arranged radially along the circumference of the circle where the respective barrel segment core molds are located.

[0013] A further technical solution of the present invention is that the outer walls of the first barrel segment core mold, the second barrel segment core mold and the fifth barrel segment core mold are all provided with ventilation grooves, which are inner grooves that axially penetrate through both ends of the barrel segment core molds for ventilation or cable installation.

[0014] A further technical solution of the present invention is: the outer walls of the second barrel segment core mold, the third barrel segment core mold, the fourth barrel segment core mold and the fifth barrel segment core mold are all provided with reinforcement grooves, and the reinforcement grooves are recessed grooves, which are used to locally form different thicknesses in the insulation covering sleeve to enhance the structural strength of the insulation covering at this position.

[0015] A further technical solution of the present invention is: the front snap seat is an L-shaped structure, including a vertically arranged positioning plate and a horizontally arranged mounting seat; the slide groove is a T-shaped groove, which is arranged on the mounting seat; the rear snap seat includes a baffle and a T-shaped slider, the baffle is parallel to the positioning plate, and a T-shaped slider matching the T-shaped slot is provided at the lower end of the baffle, and the T-shaped slider is slidably installed in the T-shaped slot; the transmission screw passes through the positioning plate and is axially limited and rotationally connected with it, the rod portion of the transmission screw is located in the T-shaped slot, and its rod portion passes through the T-shaped slider and is screwed with it; the first connecting pin is installed on the positioning plate, and the second connecting pin is installed on the baffle.

[0016] A further technical solution of the present invention is: the transmission screw is limitedly connected to the axis of the positioning plate through an axial retaining ring shaft; a handle is provided at the outer end of the transmission screw located outside the positioning plate for hand-holding and twisting the transmission screw.

[0017] A method for forming a complex thermal insulation covering sleeve using the core mold comprises the following steps:

[0018] Step 1. Connect the core molds of the barrel sections through multiple connecting buckles to complete the assembly of the barrel section core mold assembly;

[0019] Step 2. Install the head core mold at one end of the barrel core mold assembly and fix the connection through multiple connecting buckles;

[0020] Step 3. The outer surface of the core mold is fully paved with a thermal insulation film, wherein the thermal insulation film is thin-pass treated, and the thickness of the thin-pass is determined according to the requirements of the thermal insulation coating product to be formed;

[0021] Step 4. Place the core mold with the insulation film patched into a vacuum bag and tighten it by vacuuming;

[0022] Step 5. Send the core mold with the vacuum bag after step 4 into the vulcanization tank for vulcanization;

[0023] Step 6. After vulcanization is completed, take the can out and remove the vacuum bag;

[0024] Step 7. Remove all the connecting clips in the core mold, first take out the two first barrel section core molds, and then take out the remaining barrel section core molds and the head core mold; at this point, the molding of the complex insulation covering sleeve is completed.

[0025] Beneficial Effects

[0026] The beneficial effects of the present invention are as follows: the core mold for forming a complex thermal insulation covering sleeve described in the present invention, the cylinder core mold assembly is assembled by splicing a plurality of cylinder segment core molds of a fan-shaped plate structure, and the connection points of two adjacent cylinder segment core molds are butted by their respective mounting plate surfaces and fixed by a plurality of connecting buckles. The connecting plate at the bowl-mouth end of the head core mold is butted with the mounting ring surface formed by splicing the cylinder core molds at the end of the cylinder core mold assembly, and fixed by a plurality of connecting buckles. This structure makes the interface structure of the core mold components uniform, and only a plurality of connecting buckles of the same specification are required to realize detachable assembly, which is convenient for disassembly and assembly, and can effectively shorten the mold preparation time and improve production efficiency.

[0027] In the structure of the present invention, the connecting parts of the connecting buckles are all located in the inner cavity of the core mold, so that the outer surface structure of the core mold is flat and has no additional convex structure, which is convenient for laying the insulation layer film; at the same time, it is also convenient to use a vacuum bag for vacuuming and tightening, so that the vacuum bag and the core mold can be placed in a vulcanization tank as a whole for vulcanization molding of the film, and 4 to 6 products can be molded in the vulcanization tank at one time, thereby improving production efficiency.

[0028] The core mold of the present invention has a simple structure, is easy to disassemble and assemble, has good processability in the molding method, and can mold complex insulation covering sleeve parts. The quality consistency of the molded product is good, and the appearance is regular without polishing. During the molding process, the inner and outer surfaces of the core mold in the vulcanizing tank are stressed at the same time, which is different from the mold needing to bear a large pressure when molding using a flat vulcanizing machine. Therefore, the core mold of the present invention has a long service life.

[0029] The core mold of the present invention is made of steel or aluminum, the material source is wide, and the production cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall appearance structure of the core mold;

[0031] Figure 2 It is a schematic diagram of the internal connection structure of the core mold;

[0032] Figure 3 A schematic diagram of the internal connection structure of the core mold hiding the second barrel section core mold and the third barrel section core mold;

[0033] Figure 4 This is a schematic diagram of the core mold structure of the first barrel section;

[0034] Figure 5 It is a schematic diagram of the core mold structure of the second barrel section;

[0035] Figure 6 This is a schematic diagram of the core mold structure of the third barrel section;

[0036] Figure 7 This is a schematic diagram of the core mold structure of the fourth barrel section;

[0037] Figure 8 This is a schematic diagram of the core mold structure of the fifth barrel section;

[0038] Fig. 9 Schematic diagram of the overall structure of the connecting buckle Figure 1 ;

[0039] Fig.10 Schematic diagram of the overall structure of the connecting buckle Figure 2 .

[0040] Explanation of the accompanying drawings: 1. Head core mold, 11. Second ventilation groove, 12. Through hole, 2. Cylinder section core mold assembly, 21. First cylinder section core mold, 22. Second cylinder section core mold, 23. Third cylinder section core mold, 24. Fourth cylinder section core mold, 25. Fifth cylinder section core mold, 26. Positioning hole, 27. First ventilation groove, 28. Reinforcement groove, 3. Connecting buckle, 31. Front buckle seat, 311. Positioning plate, 312. Mounting seat, 313. T-slot, 32. Rear buckle seat, 321. Baffle, 322. T-slider, 33. Transmission screw, 331. Handle, 34. First connecting pin, 35. Second connecting pin, 36. Axial retaining ring. DETAILED DESCRIPTION

[0041] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0043] Embodiment 1:

[0044] See also Figure 1-3 This embodiment provides a core mold for molding a complex thermal insulation covering sleeve, which is used to mold the complex thermal insulation covering sleeve. The core mold includes a head core mold 1, a barrel section core mold assembly 2 and a connecting buckle 3.

[0045] The barrel core mold assembly 2 is a split-petal cylindrical structure, which is composed of six barrel core molds of fan-shaped plate structures with the same central axis. Two adjacent barrel core molds are detachably fixedly connected through multiple connecting buckles 3. The main body of the head core mold 1 is a bowl-shaped structure, the bowl mouth end of which is buckled to one end of the barrel core mold assembly 2, and is fixedly connected to the barrel core mold assembly 2 through multiple connecting buckles 3 evenly installed around the circumference; a through hole 12 is provided at the center of the bottom end of the bowl for matching with the thermal insulation cover product, and it is also convenient for disassembling and assembling the head core mold 1.

[0046] For details, see Figure 2-8 The barrel section core mold assembly 2 includes a first barrel section core mold 21, a second barrel section core mold 22, a third barrel section core mold 23, a fourth barrel section core mold 24 and a fifth barrel section core mold 25, wherein there are two first barrel section core molds 21 and one each of the other barrel section core molds. During installation, the first barrel section core mold 21, the second barrel section core mold 22, the third barrel section core mold 23, another first barrel section core mold 21, the fourth barrel section core mold 24 and the fifth barrel section core mold 25 are sequentially connected along the circumferential direction, and each barrel section core mold is provided with mounting plates on both sides along the circumferential direction. The mounting plates at the connection of two adjacent barrel section core molds are butted against each other, and a plurality of positioning holes 26 are evenly distributed on the mounting plates, and the positioning holes 26 on the two butted mounting plates correspond to each other one by one. The mounting plates and the positioning holes are used to install the connecting buckle 3. In order to facilitate the removal of the core mold after the sheath is formed (after the complex insulation sheath is formed, the sheath cannot be directly removed from the core mold, and the petal-type core mold needs to be split and removed piece by piece to remove the formed sheath parts), the first barrel segment core mold 21 is provided with mounting plates perpendicular to the surface where its fan-shaped chord is located on both sides of its circumference, so as to realize the vertical connection with the adjacent barrel segment core molds, and facilitate its removal during disassembly. When the core mold is disassembled, first pull the first barrel segment core mold 21 in the direction of the central axis to separate it from the sheath, and then take out the two first barrel segment core molds 21, and then take out the remaining barrel segment core molds. The second barrel segment core mold 22, the third barrel segment core mold 23, the fourth barrel segment core mold 24 and the fifth barrel segment core mold 25 are all provided with mounting plates matching the mounting plates of the first barrel segment core mold 21 on the side connected to the first barrel segment core mold 21, so as to realize the vertical connection at the corresponding connecting plates. The mounting plates at the connection between the second barrel segment core mold 22 and the third barrel segment core mold 23, and at the connection between the fourth barrel segment core mold 24 and the fifth barrel segment core mold 25 are all arranged along the radial direction of the circumference of the respective barrel segment core molds. When the barrel segment core molds are connected in sequence, the mounting plates on both sides are aligned and contacted in sequence, so that the positioning holes of the two adjacent connecting plates correspond to each other, and the two butted mounting plates and positioning holes are clamped by multiple connecting buckles 3 to achieve butt fixation, and one connecting buckle 3 is installed at each group of corresponding positioning holes 26.

[0047] An end mounting plate is provided at one end of each barrel segment core mold facing the end of the head core mold 1. When the barrel segment core molds are assembled into the barrel segment core mold assembly 2, the end mounting plate of each barrel segment core mold forms a mounting ring of the barrel segment core mold assembly 2, which serves as a positioning and mounting interface of the end of the head core mold 1. A plurality of positioning holes 26 are evenly distributed around the circumference of the mounting ring, which are used for docking and mounting with the end of the head core mold 1. An annular connecting plate is provided at the bowl-mouth end of the end of the head core mold 1, and positioning holes 26 corresponding to the positioning holes 26 on the mounting ring of the barrel segment core mold assembly 2 are provided around the connecting plate. During installation, the mounting ring is butted against the annular connecting plate surface, and the positioning holes on the mounting ring correspond to the positioning holes on the connecting plate, and then fixedly connected by a plurality of connecting buckles 3, with one connecting buckle 3 installed at each group of corresponding positioning holes 26.

[0048] The first vent groove 27 is provided on the outer wall of the first barrel section core mold 21, the outer wall of the second barrel section core mold 22, and the outer wall of the fifth barrel section core mold 25. The first vent groove 27 is an inner groove that axially penetrates the two ends of the barrel section core molds where they are located, and is used for ventilation or cable installation. Figure 1 , 3 As shown, a second ventilation groove 11 corresponding to the first ventilation groove 27 on the barrel section core mold assembly 2 is provided on the outer wall of the head core mold 1, and the second ventilation groove 11 passes through the bowl end and the through hole 12 of the head core mold 1 for ventilation or cable installation.

[0049] Reinforcement grooves 28 are provided on the outer walls of the second barrel section core mold 22, the third barrel section core mold 23, the fourth barrel section core mold 24 and the fifth barrel section core mold 25. The reinforcement grooves 28 are recessed grooves of uniform depth and are used to locally form different thicknesses in the insulation covering sleeve to enhance the structural strength of the insulation covering at this position.

[0050] In this embodiment, the second barrel section core mold 22 and the fifth barrel section core mold 25 are mirror images of each other and are located on both sides of a first barrel section core mold 21. The third barrel section core mold 23 and the fourth barrel section core mold 24 are mirror images of each other and are located on both sides of another first barrel section core mold 21. The diameter of the core mold is φ500 mm and the overall length is 2000 mm.

[0051] See also Fig. 9 , 10The connecting buckle 3 includes a front buckle seat 31, a rear buckle seat 32, a transmission screw 33, a first connecting pin 34 and a second connecting pin 35. The front buckle seat 31 is an L-shaped integral structure, including a vertically arranged positioning plate 311 and a horizontally arranged mounting seat 312. The mounting seat 312 is provided with a T-slot 313 for slidingly mounting the rear buckle seat 32. The rear buckle seat 32 includes a baffle 321 and a T-slot slider 322. The baffle 321 is arranged parallel to the positioning plate 311. The lower end of the baffle 321 is provided with a T-slot slider 322 matching the T-slot 313. The T-slot slider 322 is slidably mounted in the T-slot 313. The transmission screw 33 passes through the positioning plate 311, and its rod portion is located in the T-slot 313. The end of the rod portion of the transmission screw 33 close to the rear buckle seat 32 passes through the T-slot slider 322 and is screwed thereto. One end of the transmission screw 33 away from the rear buckle seat 32 is exposed outside the positioning plate 311, and a handle 331 is provided at the end for hand-holding and screwing the transmission screw 33. The transmission screw 33 is rotatably connected to the positioning plate 311, and is axially limited by two axial retaining rings 36 to prevent the transmission screw 33 from axial displacement. The axial retaining rings 36 are sleeved in the retaining ring groove of the transmission screw 33, one of the axial retaining rings 36 is stuck on the outer wall of the positioning plate 311, and the other is stuck on the inner wall of the positioning plate 311. The first connecting pin 34 is installed on the positioning plate 311, and the second connecting pin 35 is installed on the baffle 321. The first connecting pin 34 and the second connecting pin 35 are coaxial and face to face. By screwing the transmission screw 33, the T-shaped slider 322 of the rear buckle seat 32 moves axially along the transmission screw 33, and the distance between the baffle 321 and the positioning plate 311 can be adjusted. When screwing in the forward direction, the two connected parts can be clamped, such as clamping the two mounting plates connected to each other in the core molds of two adjacent barrel sections, or clamping the mounting ring and the annular connecting plate, and inserting the first connecting pin 34 and the second connecting pin 35 into the corresponding set of positioning holes 26; when screwing in the reverse direction, the two connected parts can be loosened and removed.

[0052] Embodiment 2:

[0053] This embodiment provides a method for forming a complex thermal insulation covering sleeve using the core mold in Embodiment 1, comprising the following steps:

[0054] Step 1. Connect each barrel segment core mold through multiple connecting buckles 3 to complete the assembly of the barrel segment core mold assembly 2. The installation method of two adjacent barrel segment core molds is: dock the two barrel segment core molds along the circumferential direction, make the two docking mounting plates contact, and align the positioning holes on the two mounting plates, install a connecting buckle 3 at each group of positioning holes, and screw the transmission screw 33 to achieve clamping and fixing.

[0055] Step 2. Install the head core mold 1 at one end of the barrel section core mold assembly 2, and connect the connecting plate at the bowl-mouth end of the head core mold 1 with the mounting ring of the barrel section core mold assembly 2 so that the positioning holes 26 on the two are aligned. At the same time, ensure that the second ventilation groove 11 on the outer surface of the head core mold 1 corresponds to the first ventilation groove 27 on the outer surface of the barrel section core mold assembly 2 one by one, and then fix the connecting plate and the mounting ring through multiple connecting buckles 3 to achieve fixed connection between the head core mold 1 and the barrel section core mold assembly 2.

[0056] Step 3. Evenly spread the insulation layer film on the outer surface of the core mold to ensure that the entire core mold surface is spread. The insulation layer film is a raw insulation film that has been processed by thin-pass treatment. The thickness of the thin-pass treatment is determined according to the requirements of the insulation coating product to be formed.

[0057] Step 4. Place the core mold with the insulation film patched into a vacuum bag, and draw a vacuum to tighten the surface insulation layer.

[0058] Step 5. Send the core mold with the vacuum bag after step 4 into the vulcanization tank for vulcanization.

[0059] Step 6. After vulcanization is completed, take the product out of the can and remove the vacuum bag.

[0060] Step 7. Remove all the connecting buckles 3 in the core mold, first take out the two first barrel section core molds 22, and then take out the remaining barrel section core molds and the head core mold 1. At this point, the molding of the complex insulation covering sleeve is completed.

[0061] The method can efficiently form composite thermal insulation covering sleeve parts while ensuring the size requirements of complex thermal insulation covering sleeves, thereby improving the consistency of products.

[0062] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A core mold for molding a complex thermal insulation sheath, characterized in that: It includes a head core mold, a barrel section core mold assembly and a connecting buckle; The barrel segment core mold assembly comprises a plurality of fan-shaped barrel segment core molds, and the plurality of barrel segment core molds are sequentially connected along the same circumferential surface to form a barrel segment core mold assembly with a columnar barrel structure; two adjacent barrel segment core molds are detachably fixedly connected by a plurality of connecting buckles; The main body of the end cap core mold is a bowl-shaped structure, the mouth of which is buckled to one end of the barrel section core mold assembly, and is fixedly connected to the barrel section core mold assembly through a plurality of connection buckles evenly installed around the circumference; The connecting buckle includes a front buckle seat, a rear buckle seat, a transmission screw, a first connecting pin and a second connecting pin; the front buckle seat is provided with a slide groove, and the rear buckle seat is slidably installed in the slide groove; the transmission screw is threadedly connected to the rear buckle seat, and is used to drive the rear buckle seat to slide along the groove direction of the slide groove; the first connecting pin and the second connecting pin are respectively installed on the front buckle seat and the rear buckle seat, and are coaxially arranged opposite to each other; the distance between the rear buckle seat and the front buckle seat is adjusted by screwing the transmission screw, so as to clamp the two connected parts, at this time, the first connecting pin and the second connecting pin are correspondingly inserted into the positioning holes of the connected parts on their sides.

2. The core mold for forming a complex thermal insulation sheath according to claim 1, characterized in that: The barrel section core mold assembly comprises a first barrel section core mold, a second barrel section core mold, a third barrel section core mold, a fourth barrel section core mold and a fifth barrel section core mold, wherein two first barrel section core molds are provided, and the remaining barrel section core molds are provided with one each; during installation, the first barrel section core mold, the second barrel section core mold, the third barrel section core mold, another first barrel section core mold, the fourth barrel section core mold and the fifth barrel section core mold are sequentially connected along the circumferential direction, and each barrel section core mold is provided with mounting plates on both sides along the circumferential direction, and the mounting plates at the connection of two adjacent barrel section core molds are butted against each other, and a plurality of positioning holes are evenly distributed on the mounting plates for installing connecting buckles.

3. The core mold for forming a complex thermal insulation sheath according to claim 2, characterized in that: An end mounting plate is provided at one end of each barrel segment core mold facing the head core mold; the end mounting plate of each barrel segment core mold forms a mounting ring of the barrel segment core mold assembly, and a plurality of positioning holes are evenly distributed around the circumference of the mounting ring; an annular connecting plate is provided at the bowl-mouth end of the head core mold, and the connecting plate is provided with positioning holes corresponding to the positioning holes on the mounting ring one by one; the mounting ring is butted against the connecting plate surface and fixedly connected by a connecting buckle.

4. The core mold for forming a complex thermal insulation sheath according to claim 2, characterized in that: The first barrel segment core mold is provided with mounting plates perpendicular to the surface where its fan-shaped chord is located on both sides along its circumference, and the connecting sides of the remaining barrel segment core molds and the first barrel segment core mold are provided with mounting plates matching the mounting plates of the first barrel segment core mold; the mounting plates at the connection between the second barrel segment core mold and the third barrel segment core mold and at the connection between the fourth barrel segment core mold and the fifth barrel segment core mold are all arranged radially along the circumference of the circle where the respective barrel segment core molds are located.

5. The core mold for forming a complex thermal insulation sheath according to claim 2, characterized in that: The outer walls of the first barrel segment core mold, the second barrel segment core mold, and the fifth barrel segment core mold are all provided with ventilation grooves, which are inner grooves that axially penetrate the two ends of the barrel segment core molds where they are located, and are used for ventilation or cable installation.

6. The core mold for forming a complex thermal insulation sheath according to claim 2, characterized in that: The outer walls of the second barrel section core mold, the third barrel section core mold, the fourth barrel section core mold and the fifth barrel section core mold are all provided with reinforcement grooves, which are recessed grooves used to locally form different thicknesses on the insulation covering sleeve to enhance the structural strength of the insulation covering at this position.

7. The complex heat-insulating sheath molding core mold according to claim 2, characterized in that: The front snap seat is an L-shaped structure, including a vertically arranged positioning plate and a horizontally arranged mounting seat; the slide groove is a T-shaped groove, which is arranged on the mounting seat; the rear snap seat includes a baffle and a T-shaped slider, the baffle is parallel to the positioning plate, and a T-shaped slider matching the T-shaped slot is provided at the lower end of the baffle, and the T-shaped slider is slidably installed in the T-shaped slot; the transmission screw passes through the positioning plate and is axially limited and rotationally connected with it, the rod portion of the transmission screw is located in the T-shaped slot, and its rod portion passes through the T-shaped slider and is screwed with it; the first connecting pin is installed on the positioning plate, and the second connecting pin is installed on the baffle.

8. The core mold for forming a complex thermal insulation sheath according to claim 7, characterized in that: The transmission screw is limitedly connected with the axis of the positioning plate through an axial retaining ring; the outer end of the transmission screw located outside the positioning plate is provided with a handle for hand-holding and screwing the transmission screw.

9. A method for forming a complex thermal insulation covering sleeve using the core mold according to claim 8, characterized in that: The following steps are involved: Step 1. Connect the core molds of the barrel sections through multiple connecting buckles to complete the assembly of the barrel section core mold assembly; Step 2. Install the head core mold at one end of the barrel core mold assembly and fix the connection through multiple connecting buckles; Step 3. The outer surface of the core mold is fully paved with a thermal insulation film, wherein the thermal insulation film is thin-pass treated, and the thickness of the thin-pass is determined according to the requirements of the thermal insulation coating product to be formed; Step 4. Place the core mold with the insulation film patched into a vacuum bag and tighten it by vacuuming; Step 5. Send the core mold with the vacuum bag after step 4 into the vulcanization tank for vulcanization; Step 6. After vulcanization is completed, take the can out and remove the vacuum bag; Step 7. Remove all the connecting clips in the core mold, first take out the two first barrel section core molds, and then take out the remaining barrel section core molds and the head core mold; at this point, the molding of the complex insulation covering sleeve is completed.

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