Disposable quick-release core mold for NOL ring forming and use method of disposable quick-release core mold

Abstract

In order to solve the problems that an NOL ring mold is complex to assemble and consumes time, the invention develops a low-cost disposable quick-release mold. The NOL ring is a furnace part which must be provided for delivery of workpieces such as a composite material pressure container and a barrel and is used for judging the process quality. In addition, the NOL ring is also a main part for screening a resin formula and researching a curing process and a winding process, and the demand quantity is large. A conventional NOL ring mold is a metal mold and is inconvenient to disassemble and assemble and low in efficiency. The disc-shaped glass sheet with the mounting shaft hole is used as the disposable sacrifice core mold and has the advantages of being rapid to assemble, convenient to disassemble, low in cost and high in efficiency, and due to the fact that the surface of the glass core mold is smooth, the apparent quality of the prepared NOL ring is superior to that of a metal mold.

Description

Technical Field

[0001] This invention relates to the field of composite material molding technology, specifically to a disposable quick-release mandrel for NOL ring winding molding and its usage method. Background Technology

[0002] NOL rings are used as in-furnace quality verification components for composite pressure vessels, cylinders, and other parts, as well as key samples for resin formulation screening, curing, and winding process research. They are in high demand and require high preparation efficiency. Traditional NOL ring preparation uses metal mandrels, requiring complex structural assembly to form the cavity, which presents the following problems: The tooling structure is complex: metal core molds are usually composed of multiple nested components, which are time-consuming to assemble and cumbersome to operate; Demolding difficulties: After winding and curing, the clamping force between the metal core mold and the composite material makes it easy to cause damage to the NOL ring during the demolding process, affecting the stability of test data and even causing the failure of formula screening. Cost versus efficiency conflict: Although improved metal core molds have been developed to address the demolding problem, they still suffer from the drawback of complex assembly and disassembly, making it difficult to meet the needs of mass production.

[0003] To address the aforementioned issues, this invention proposes a disposable quick-release core mold solution, which achieves efficient and low-cost fabrication of NOL rings through material innovation and structural simplification. Summary of the Invention

[0004] Technical solution The core of this invention lies in providing a disposable sacrificial glass core mold, the specific technical solution of which is as follows: One-time quick-release core mold structure The core mold includes: Glass core mold: It uses a disc-shaped glass sheet with mounting shaft holes, with an inner diameter of 50mm, an outer diameter of 150mm, and a thickness of 6mm. The material is ordinary glass, which is cut into shape by a glass cutter. Auxiliary components include a 50mm diameter mounting rod shaft, a hollow ring (inner radius 25mm, outer radius 78mm, thickness 6mm), a limiting outer ring, and locking bolts.

[0005] How to use Core mold assembly: The glass core mold is fitted onto the mounting rod shaft, and hollow rings are assembled alternately on both sides to form multiple independent annular winding cavities (e.g., 4 cavities can be achieved by combining 5 hollow rings with 4 glass core molds); one end of the mounting rod shaft is equipped with a limiting ring (6mm thick, 66mm in diameter), and the other end is axially fixed by a limiting outer ring and locking bolts to prevent the tooling from sliding.

[0006] Winding and curing: The assembled tooling is installed on the winding machine, and the composite material is continuously wound in the annular cavity. The number of winding turns is controlled so that the NOL ring thickness reaches 3mm. After winding, the entire tooling is placed in the curing oven for rolling curing.

[0007] Demolding and part removal: After curing, remove the limiting outer ring, separate the hollow circular ring, and directly break the glass core mold to obtain an undamaged NOL ring sample. Beneficial effects

[0008] Highly efficient and convenient: Glass core molds do not require complex assembly. They can be quickly positioned by mounting rods and hollowed-out rings. A single tooling set can prepare multiple NOL rings at the same time. When demolding, simply break the glass. This saves more than 50% of the operation time compared to metal core molds. Excellent quality: The glass surface has a high degree of smoothness, and the apparent quality of the NOL ring is superior to that of metal core molded products, with a dimensional accuracy error of ≤0.1mm; Low cost: The cost of ordinary glass materials is only 1 / 20 of that of metal core molds, and the processing and maintenance costs of metal core molds are eliminated; High versatility: By adjusting the size of the glass core mold (such as diameter, thickness, and shape), it can be extended to the preparation of similar parts such as rings, cylinders, and ellipses, with a wide range of applications. Attached Figure Description

[0009] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 Exploded view of one-time quick-release core mold assembly (1-mounting rod shaft, 2-hollow ring, 3-limiting outer ring, 4-glass core mold, 5-limiting ring). Figure 2 : Schematic diagram of mold connection when multiple sets of NOL rings are wound; Figure 3 : Schematic diagram of glass core mold structure (inner diameter, outer diameter, and thickness are marked); Figure 4 : Schematic diagram of a hollow circular ring structure with positioning groove. Detailed Implementation

[0010] Example 1: Preparation of standard NOL rings: Tooling assembly: Select a 500mm long mounting rod shaft (50mm in diameter), with a one-piece molded limiting ring at one end (50mm from the end, 6mm thick, 66mm in diameter); sequentially install 4 sets each of hollow circular rings and glass core molds to form 4 annular cavities; install a limiting outer ring at the other end and fix it with an M8 locking bolt to ensure uniform cavity spacing.

[0011] Winding process: Install the fixture on the winding machine, set the winding angle to 55° and the yarn tension to 8N, and continuously wind in 4 cavities. After each cavity is wound to a thickness of 3mm, the machine will automatically switch to the next cavity. The total winding time is about 40 minutes.

[0012] Curing and demolding: Place the tool in a curing oven and heat it to 120℃ at 2℃ / min, keep it at that temperature for 2 hours, and keep it rotating at 5 rpm during the process; after curing, remove the limiting outer ring, separate the hollow ring, and gently tap the glass core mold with a rubber hammer to obtain 4 standard NOL rings with a diameter of 150mm×3mm and a width of 6mm. The demolding success rate is 100%.

[0013] Example 2: Extended Application (Cylindrical Parts) By adjusting the glass core mold dimensions to an inner diameter of 50mm, an outer diameter of 150mm, and a thickness of 20mm, and replacing the hollow ring with a structure suitable for an inner diameter of 50mm, and using the same assembly and demolding methods, a cylindrical part with an inner diameter of 150mm, a width of 20mm, and a thickness of 3mm can be prepared, verifying the versatility of this invention in similar parts.

[0014] Scope expansion The core of this invention lies in the combination scheme of "disposable sacrificial glass core mold + auxiliary positioning component". Any similar part preparation method that achieves rapid assembly and disassembly by adjusting the shape (such as ellipse, irregular shape), size or material (such as tempered glass, quartz glass) of the glass core mold is within the scope of protection of this invention.

Claims

1. A disposable quick-release mandrel for NOL ring forming, characterized in that: The device includes a disc-shaped glass core mold (4) with a mounting shaft hole. The glass core mold (4) is a disposable sacrificial part with an inner diameter of 50 mm, an outer diameter of 150 mm, and a thickness of 6 mm. It also includes a hollow ring (2) for positioning, a mounting rod shaft (1) with a diameter of 50 mm, a limiting outer ring (3), and a locking bolt. The hollow ring (2) has an inner radius of 25 mm, an outer radius of 78 mm, and a thickness of 6 mm. It is alternately fitted with the glass core mold (4) on the mounting rod shaft (1) and axially locked by the limiting outer ring (3).

2. The core mold according to claim 1, characterized in that: The glass core mold (4) is made of ordinary glass and is cut into shape by a glass cutter.

3. A method of using the core mold according to claim 1 or 2, characterized in that, Includes the following steps: a. Assembly: The glass core mold (4) and the hollow ring (2) are alternately fitted onto the mounting rod shaft (1). One end of the mounting rod shaft (1) is provided with a limiting ring (5), and the other end is fixed by a limiting outer ring (3) and a locking bolt to form at least one annular winding cavity; b. Wrapping and curing: Install the tooling on the wrapping machine, wrap the composite material in the cavity to the preset thickness (3mm), and place the whole thing in the curing oven for rolling and curing; c. Demolding: Remove the limiting outer ring (3), separate the hollow circular ring (2), break the glass core mold (4), and take out the NOL ring.

4. The method according to claim 3, characterized in that: In step a, five hollow rings (2) and four glass core molds (4) are combined to form four independent annular winding cavities, enabling the simultaneous preparation of multiple parts.

5. The method according to claim 3, characterized in that: The mounting rod shaft (1) has a length of 500-1200mm, and the limiting ring (5) has a thickness of 6mm and a diameter of 66mm, and is integrally formed with the mounting rod shaft (1).

6. The core mold according to claim 1, characterized in that: By adjusting the inner diameter, outer diameter, thickness, or shape (such as ring or ellipse) of the glass core mold (4), it can be used to prepare ring-shaped, cylindrical, or irregularly shaped composite parts of non-NOL ring standard sizes.

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