Hybrid manufacturing by machining and molding of large Fresnel lenses - H3M process

Abstract

The Hybrid Manufacturing by Machining and Molding (H3M) process involves manufacturing giant Fresnel lenses (diameter greater than or equal to 1.5 meters) using an innovative hybrid machining and compression molding process. The invention involves heating a tool (2) and moving it by combining rotation and sliding concentrically with a plate of thermoformable material (3) while applying pressure to the tool to mold and machine the plate with each pass, thereby producing the facets of a Fresnel lens with high precision. The manufactured plates assemble to form a single large Fresnel lens with a diameter greater than or equal to 1.5 meters. This hybrid process allows for faster and more efficient production of Fresnel lenses with a diameter greater than or equal to 1.5 meters compared to traditional processes. Figure for abstract [Fig 1].

Description

Title of the invention: Hybrid manufacturing by machining and molding of large Fresnel lens - H3M process

[0001] The H3M process (for Hybrid Manufacturing by Machining and Molding) concerns the manufacturing of giant optical lenses, in particular Fresnel lenses with a diameter greater than or equal to 1.5 meters. More precisely, the manufacturing of assemblable sub-parts of these large lenses using a hybrid technology combining compression molding and machining. This hybrid technology makes it possible to obtain high optical quality while maintaining cost control in the production of very large Fresnel lenses, which is crucial for applications requiring high optical quality as well as large format lenses.

[0002] The manufacture of large format Fresnel lenses has traditionally been carried out using either press-molding methods or machining. Each of these methods has limitations in terms of production speed and quality. Traditional molding can provide high surface quality, but is often limited by the size and shape of the parts produced, as well as the costs associated with producing expensive molds. Machining, on the other hand, can produce larger and more complex parts, but can be slower and more expensive due to the need to maintain high precision for cutting tools. The method of manufacturing assemblable Fresnel lens sub-parts, according to the invention combining molding and machining, offers a more efficient alternative for the production of large and very large format Fresnel lenses.

[0003] The process begins with the preparation of the plates of material to be manufactured into Fresnel lenses. The plates are made of a thermoformable material having optical properties of light transmission, such as transparent glass or transparent acrylic. They take shapes, for example, triangular, trapezoidal, or any assemblable shapes having the property of forming larger surfaces of polygonal or circular shapes. These plates are then manufactured to represent a sub-part of the large Fresnel lens.

[0004] The plate to be manufactured is arranged and held in position under a tool in the form of a conical roller potentially adjustable in its length, serving both as a positive mold and as a tool for machining the facets of a Fresnel lens. The end of the conical roller with the smallest radius corresponds to the facets of the center of the Fresnel lens. The end of the conical roller with the largest radius corresponds to the facets of the outer edges of the Fresnel lens. The roller The conical tool is heated and maintained at a temperature between 40°C and 1600°C to deform the plate to be manufactured (This temperature range makes it possible to adapt to several types of materials). A press system exerts uniform pressure on the roller to constrain the conical roller to the plate to be manufactured. The movement of the conical tool can be rolling with sliding and rolling without sliding relative to the plate. Constant pressure is applied by the roller on the plate, and the roller can make several passes if necessary. The different movements combine machining and compression molding and constitute an innovative process for manufacturing a large Fresnel lens.

[0005] [Fig.l] represents, seen from above, the hybrid process comprising the rotational guidance system (1), the conical roller (2) as well as the manufacturing plate (3) which is a sub-part of the Fresnel lens.

[0006] [Fig.2] shows, seen in profile, the hybrid process comprising the roller conical (2) as well as the manufacturing plate (3) which is a sub-part of the Fresnel lens. The roller is pressed onto the manufacturing plate.

[0007] [Fig.3] shows examples of different shapes of the assemblable sub-parts of the large Fresnel lenses.

[0008] [Fig.4] shows examples of assemblies forming a single large lens Fresnel with a diameter greater than or equal to 1.5m.

[0009] The hybrid manufacturing device comprises the following elements:

[0010] a. A molding and machining tool taking the form of a conical roller.

[0011] b. Plates made of thermoformable materials of various shapes which can be assembled into large Fresnel lenses.

[0012] c. A press system applying pressure from the conical roller to a plate to be manufactured.

[0013] d. A system for heating and maintaining the temperature of the conical roller tool.

[0014] e. A system for rotating the conical roller.

[0015] f. A system for guiding the rotation of the conical roller concentric with the lens of Fresnel.

[0016] The molding and machining tool (element a) has the shapes of a positive mold of the facets of a Fresnel lens. The conical roller with positive shapes of the facets of a Fresnel lens is heated and maintained at a sufficient temperature between 40° and 1600°C in order to deform plates to be manufactured, and pressure of the tool on the plate to be manufactured allows compression molding during the manufacturing process. These actions lead to the plates taking the shape of the positive facets of the molding tool. The movements of the tool include rolling without sliding for the molding part and rolling with sliding for the machining part of the plate.

[0017] The plates thus manufactured are subjected to a deburring process to remove rough edges, then adjusted to ensure dimensional accuracy.

[0018] The manufacturing process described in this patent allows the production of large Fresnel lenses (diameter greater than or equal to 1.5 meters), lenses used in numerous fields of application such as the production of solar energy, the heating of materials for industrial processes such as foundry, metallurgy or chemical treatment, or even scientific research whether for the study of the behavior of light, laser concentration or for the development of optical technology.

[0019] This process can have a great impact on the efficiency and cost reduction of these different sectors of activity, which makes it a valuable tool for engineers, researchers and industrialists working in these fields.

Claims

Claims

1. Hybrid manufacturing device combining compression molding and machining for the manufacture of assemblable sub-parts of Fresnel lenses with a diameter greater than or equal to 1.5 meters, characterized in that it comprises the following elements: a. A molding and machining tool in the form of a conical roller. b. Plates made of thermoformable materials having optical properties of light transmission, such as transparent glass or transparent acrylic, of various shapes that can be assembled into Fresnel lenses with a diameter greater than or equal to 1.5 meters. c. A press system applying pressure from the conical roller to a plate to be manufactured. d. A system for heating and maintaining the temperature of the conical roller tool. e. A system for rotating the conical roller. f. A system for guiding the rotation of the conical roller concentric with the Fresnel lens.

2. Manufacturing device according to claim 1 characterized in that the tool has the shapes of a positive mold of the facets of a Fresnel lens.

3. Method of implementing the device according to claim 2 characterized in that the tool with positive shapes of the facets of a Fresnel lens is heated and maintained at a temperature between 40° and 1600°C in order to deform the plates to be manufactured.

4. Method according to claim 3 characterized in that a uniform pressure of the tool is applied to the plate to be manufactured allowing compression molding during the manufacturing process.

5. Manufacturing method according to claims 3 and 4, characterized in that the tool performs rolling movements without sliding for the molding part, and rolling with sliding for the machining part of the plate.

6. Method according to claims 3, 4 and 5, characterized in that the assembled manufactured plates take the shapes of the facets positive of the roll.

7. Manufacturing method according to claim 6 characterized in that the plates of the material to be manufactured form assemblable sub-parts of a Fresnel lens with a diameter greater than or equal to 1.5 meters.

8. Method according to claim 7, characterized in that the manufactured Fresnel lens sub-parts assemble to form a polygonal or circular Fresnel lens with a diameter greater than or equal to 1.5 meters.

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