Precise forming method of large-size thin-wall glass concave mirror
By combining the vacuum negative pressure technology of the heating chamber and the concave cavity mold during the forming process of large-size thin-wall glass concave mirror, the problems of complex and high cost in the existing technology are solved, and high efficiency and low cost are achieved Surface shape accuracy and processing efficiency.
Patent Information
- Application Number
- CN202411796272.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-01-07
AI Technical Summary
The existing large-size thin-walled glass concave mirrors have complex forming processes, high cost, low surface shape accuracy and processing efficiency. In particular, the processing of large-size reflectors requires customized equipment, and the cumbersome grinding process increases production costs.
The heating chamber and concave cavity mold are combined with vacuum negative pressure technology, and the precision forming of the glass substrate is achieved by uniformly distributing the negative pressure micropores on the surface of the mold and controlling the heating temperature and negative pressure.
The processing process is simplified, the cost is reduced, and the surface shape accuracy and processing efficiency are significantly improved. It can accelerate the forming by negative pressure under high temperature environments and ensure surface shape fit, which improves the forming accuracy.
Smart Images
Figure CN119263606A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of glass forming, and in particular relates to a precision forming method for a large-size thin-walled glass concave mirror, which can be applied to the forming of various flat glass concave mirrors such as ordinary glass, borosilicate glass, etc. Background Art
[0002] Large-sized (200-600mm) thin-walled concave glass reflectors are commonly used optical reflective devices in lighting optical systems. These lighting systems use high-power xenon lamps and metal halide lamps as light sources, and the inner surface shape is generally spherical or ellipsoidal. Usually, this type of reflector adopts a molding process, and after the basic shape is formed, optical cold processing grinding and polishing are performed, otherwise the surface accuracy will not meet the use requirements, affecting the convergence efficiency. Due to the use of optical cold processing technology, the size and depth of the reflector are limited. The processing of large-sized reflectors requires customized special equipment. At the same time, the size of the ground lens is large, and it must go through rough grinding, fine grinding, polishing and other processes, which greatly increases the production cost. Summary of the invention
[0003] The present invention aims to overcome the shortcomings of the prior art and provide a precision forming method for a large-size thin-walled glass concave mirror with a simple processing process, low cost, high surface accuracy and processing efficiency.
[0004] To solve the above technical problems, the present invention is achieved as follows: A precision forming method for a large-size thin-walled glass concave mirror comprises the following steps: (1) placing a circular glass substrate on a concave cavity mold in a heating chamber; (2) Setting the heating temperature, temperature rise time, constant temperature control, constant temperature time and cooling time of the heating chamber; starting the power supply, raising the temperature to the glass softening point of the circular glass substrate and then performing constant temperature control when the temperature starts to move downward; (3) After the constant temperature is completed, the vacuum pump is started to apply negative pressure to the cavity of the concave cavity mold. When the circular glass substrate and the concave surface of the concave cavity mold are in a bonded state, the heating power is turned off and the heating chamber is cooled.
[0005] Furthermore, in step (3) of the present invention, the negative pressure in the negative pressure operation is controlled at 0.3-0.6 MPa, and the heating temperature of the heating chamber is controlled at 600-800°C.
[0006] Furthermore, negative pressure micropores are evenly distributed on the concave surface of the concave cavity mold; and the negative pressure micropores are communicated with the cavity of the concave cavity mold.
[0007] Furthermore, the diameter of the negative pressure micropores is 0.5-1 mm, and the micropore spacing is 20-30 mm.
[0008] Furthermore, the concave cavity mold is made of graphite, ceramic material or stainless steel material.
[0009] Furthermore, the diameter of the circular glass substrate is 200-600 mm.
[0010] The present invention has the characteristics of simple processing, low cost, high surface shape accuracy and processing efficiency, etc. By evenly distributing negative pressure micropores with a diameter of 0.5 to 1 mm on the concave surface of the concave cavity mold, the forming accuracy and processing efficiency can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a structural schematic diagram of the molding system of the present invention; Figure 2 It is a schematic diagram of the concave cavity mold structure of the present invention.
[0012] In the figure: 1. concave cavity mold; 2. negative pressure micropore; 3. round glass substrate; 4. heating chamber; 5. vacuum pump; 6. pressure regulating valve. DETAILED DESCRIPTION
[0013] like Figures 1-2 As shown, the precision forming method of the thin-walled glass concave mirror comprises the following steps: (1) placing a circular glass substrate 3 on a concave cavity mold 1 in a heating chamber 4; (2) Setting the heating temperature, temperature rise time, constant temperature control, constant temperature time and cooling time of the heating chamber 4; starting the power supply, programmatically raising the temperature to the glass softening point of the circular glass substrate 3 and then performing constant temperature control when it starts to move downward; (3) After the constant temperature is completed, the vacuum pump is started to apply negative pressure to the cavity of the concave cavity mold 1. When the circular glass substrate 3 and the concave surface of the concave cavity mold 1 are in a bonded state, the heating power is turned off and the heating chamber 4 is cooled.
[0014] In step (3) of the present invention, the negative pressure in the negative pressure operation is controlled at 0.3-0.6MPa, and the heating temperature of the heating chamber is controlled at 600-800°C. The present invention evenly distributes negative pressure micropores 2 on the concave surface of the concave cavity mold 1; the negative pressure micropores 2 are connected to the cavity of the concave cavity mold 1. The diameter of the negative pressure micropores 2 of the present invention is 0.5-1mm, and the micropore spacing is 20-30mm. The concave cavity mold 1 of the present invention is made of graphite, ceramic material or stainless steel material. The diameter of the circular glass substrate 3 of the present invention is 200-600mm.
[0015] The present invention can realize the molding of thin-walled concave glass reflectors; the hot bending mold adopts ceramic, graphite material or stainless steel material, and the surface design is uniformly distributed with micropores to form a vacuum negative pressure channel; the vacuum negative pressure is controlled by a valve. The present invention adopts a high temperature field (600-800°C) environment, and the flat circular glass substrate 3 is naturally sunk by heating through the concave cavity mold 1. In order to improve the forming accuracy and processing efficiency, through holes of 0.5-1mm are evenly distributed on the concave surface of the concave cavity mold 1. The lower part of the concave cavity mold is a closed hollow structure, and the outside is connected to the vacuum system. When the circular glass substrate reaches the glass softening point and starts to move downward, the vacuum negative pressure system is started to form a negative pressure inside the concave cavity mold, and the negative pressure is transmitted between the mold and the substrate through the through hole. On the one hand, the negative pressure will accelerate the forming process; on the other hand, the negative pressure makes the circular glass substrate 3 fit tightly on the concave cavity mold 1, so that the hot-bent concave glass has the same surface shape accuracy as the mold 1. The concave cavity mold 1 is made of high temperature resistant graphite and ceramic materials, and can also be made of stainless steel. The negative pressure is controlled at 0.3-0.6MPa, and the electric furnace temperature is controlled at 600-800°C. Different heating temperatures can be designed according to different glass grades.
[0016] The main equipment of the present invention includes: a heating chamber, a concave cavity mold, a vacuum pump, a vacuum connection system, a pressure regulating valve, a vacuum gauge, an industrial control system cabinet, etc.
[0017] a. Heating chamber: heats the concave cavity mold and the round glass substrate to 600-800℃, has PID heating function, and maintains constant temperature.
[0018] b. Concave cavity mold: Made of silicon carbide material, the surface is precisely ground and has good surface accuracy; the surface of the concave cavity mold has a porous structure, such as Figure 2 shown.
[0019] c. Vacuum pump: generates vacuum negative pressure.
[0020] d. Vacuum connection system: connect the vacuum pump and the concave cavity mold.
[0021] e. Pressure regulating valve: Located on the vacuum connection system, adjusting the valve can control the pressure of the concave cavity mold.
[0022] f. Vacuum gauge: Located at the end of the vacuum connection system, it is used to monitor the negative pressure of the concave cavity mold during hot bending.
[0023] g. Industrial control system: controls the heating of high temperature furnace and the start and stop of vacuum pump.
[0024] In order to make those skilled in the art better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. These embodiments should be understood to be only used to illustrate the present invention and not to limit the protection scope of the present invention. After reading the contents recorded in the present invention, all other embodiments obtained after various changes or modifications made to the present invention based on the technical solution and embodiments of the present invention also fall within the scope of protection of the claims of the present invention.
[0025] The above-described embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention. It should be noted that for those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A precision forming method for a large-size thin-walled glass concave mirror, characterized in that: The steps include: (1) placing a circular glass substrate on a concave cavity mold in a heating chamber; (2) Setting the heating temperature, temperature rise time, constant temperature control, constant temperature time and cooling time of the heating chamber; starting the power supply, raising the temperature to the glass softening point of the circular glass substrate and then performing constant temperature control when the temperature starts to move downward; (3) After the constant temperature is completed, the vacuum pump is started to apply negative pressure to the cavity of the concave cavity mold. When the circular glass substrate and the concave surface of the concave cavity mold are in a bonded state, the heating power is turned off and the heating chamber is cooled.
2. The precision forming method of a large-size thin-walled glass concave mirror according to claim 1, characterized in that: In step (3), the negative pressure in the negative pressure operation is controlled at 0.3-0.6 MPa, and the heating temperature of the heating chamber is controlled at 600-800°C.
3. The precision forming method of a large-size thin-walled glass concave mirror according to claim 2, characterized in that: Negative pressure micropores are evenly distributed on the concave surface of the concave cavity mold; the negative pressure micropores are communicated with the cavity of the concave cavity mold.
4. The precision forming method of a large-size thin-walled glass concave mirror according to claim 3, characterized in that: The diameter of the negative pressure micropores is 0.5-1 mm.
5. The precision forming method of a large-size thin-walled glass concave mirror according to claim 4, characterized in that: The concave cavity mold is made of graphite, ceramic material or stainless steel material.
6. The precision forming method of a large-size thin-walled glass concave mirror according to claim 5, characterized in that: The diameter of the circular glass substrate is 200-600 mm.