阅读说明：本技术 氟磷酸盐光学玻璃条料成型厚度控制装置及方法 (Fluorophosphate optical glass strip forming thickness control device and method ) 是由 焦胜兵 周国文 于 2020-05-29 设计创作，主要内容包括：本发明涉及一种氟磷酸盐光学玻璃条料成型厚度控制装置及方法。所述厚度控制装置包括放料单元、成型单元、牵引单元、检测单元和控制单元。放料单元由铂金出料管及其温度控制系统组成。成型单元由模具底板、左右侧板、后挡板及盖板组成。牵引单元由传送带、辊轮及变频电机组成。检测单元由激光测距仪及其安装支架组成。控制单元由可编程控制器、变频器组成。控制方法为,激光测距仪垂直或倾斜安装在成型单元上方,实时监测玻璃液表面高度变化,将检测的距离数据传送到可编程控制器,换算成表征成型厚度变化的有效数据,并与预定数据进行比较,采用PID调节控制,对变频器的输出频率进行修正,从而实现玻璃条料成型厚度的精准控制。(The invention relates to a fluorophosphate optical glass strip material forming thickness control device and method. The thickness control device comprises a discharging unit, a forming unit, a traction unit, a detection unit and a control unit. The discharging unit consists of a platinum discharging pipe and a temperature control system thereof. The molding unit consists of a mold bottom plate, a left side plate, a right side plate, a rear baffle plate and a cover plate. The traction unit consists of a conveyor belt, a roller and a variable frequency motor. The detection unit consists of a laser range finder and a mounting bracket thereof. The control unit consists of a programmable controller and a frequency converter. The control method comprises the steps that the laser range finder is vertically or obliquely arranged above the forming unit, the height change of the surface of the molten glass is monitored in real time, the detected distance data are transmitted to the programmable controller, the effective data representing the change of the forming thickness are converted, the effective data are compared with preset data, PID (proportion integration differentiation) regulation control is adopted, the output frequency of the frequency converter is corrected, and therefore the accurate control of the forming thickness of the glass strip is achieved.)

1. The utility model provides a fluorophosphate optical glass strip material shaping thickness control device, includes blowing unit, shaping unit, traction unit, the blowing unit comprises platinum discharging pipe and temperature control system, the shaping unit comprises mould bottom plate, left and right sides curb plate, backplate and apron, traction unit comprises metal conveying mesh belt, drive and driven running roller and inverter motor, its characterized in that, the device includes:

the detection unit consists of a laser range finder and a mounting bracket thereof and is used for detecting the change of the liquid level height of the molten glass near the discharge pipe orifice in the forming die in the cover plate through the measurement through hole;

and the control unit consists of a programmable controller and a frequency converter, is respectively connected with the laser range finder and the variable frequency motor, and is used for correcting the output frequency of the frequency converter based on the comparison between the detection value obtained from the laser range finder and a preset value, so that the linear velocity of the metal conveying net belt is adjusted, and the thickness precision control in the optical glass strip forming process is finally realized.

2. The control device according to claim 1, wherein the measuring object of the laser range finder is an opaque object, the measuring range is 1000-5000mm, the measuring precision is 0.01mm, and the measuring spot (7) projected on the surface of the measuring object is a square with a side length of 8-12mm in normal use.

3. The control device of claim 2, wherein the programmable controller comprises a human-computer data interaction platform, a standard MODBUS communication component, and an analog output component; the frequency converter is set to a corresponding analog input control mode.

4. The control device of claim 3, wherein the laser range finder is vertically installed above the forming unit according to the field environment or process requirements, the cover plate is provided with a measuring through hole and is connected with a standard MODBUS communication component of the programmable controller through a communication data line, an analog output component of the programmable controller is connected with an analog control terminal of the frequency converter through an output signal line, and a power output end of the frequency converter is connected with the variable frequency motor through a power line.

5. The control device of claim 3, wherein the laser range finder is obliquely arranged above the forming unit according to the field environment or process requirements, and is connected with a standard MODBUS communication component of the programmable controller through a communication data line, an analog output component of the programmable controller is connected with an analog control terminal of the frequency converter through an output signal line, and a power output end of the frequency converter is connected with the variable frequency motor through a power line.

6. A fluorophosphate optical glass strip forming thickness control method is characterized by comprising a discharging unit, a forming unit, a traction unit, a detection unit and a control unit; the discharging unit consists of a platinum discharging pipe and a temperature control system thereof; the forming unit consists of a die bottom plate, a left side plate, a right side plate, a rear baffle and a cover plate; the traction unit consists of a metal conveying mesh belt, driving and driven rollers and a variable frequency motor; the detection unit consists of a laser range finder, a mounting bracket thereof and a measurement through hole arranged on the cover plate; the control unit consists of a programmable controller and a frequency converter and is respectively connected with the laser range finder and the variable frequency motor;

the laser range finder monitors the change of the liquid level height of the molten glass near the discharge pipe orifice in the forming die in the cover plate in real time;

based on the detection value obtained from the laser range finder, the output frequency of the frequency converter is corrected by comparing with a preset value, so that the linear velocity of the metal conveying mesh belt is adjusted, and the thickness precision control in the optical glass strip forming process is finally realized.

7. The control method according to claim 6, wherein the measuring object of the laser range finder is an opaque object, the measuring range is 1000-5000mm, the measuring precision is 0.01mm, and the measuring spot (7) projected on the surface of the measuring object is a square with a side length of 8-12mm during normal use; the laser range finder monitors the change of the liquid level height of the molten glass near the discharge pipe orifice in the forming die in the cover plate in real time through the measuring through hole, and transmits the detected distance data to a programmable controller in the control unit in an MODBUS communication mode;

based on the distance data obtained from the laser range finder, the programmable controller converts effective data representing the forming thickness change of the glass strip through system operation, and inputs a 4-20mA analog signal for controlling the frequency output of the frequency converter to the frequency converter by adopting PID regulation control according to the comparison relation between the effective data and preset data, so as to correct the output frequency of the frequency converter, thereby realizing the linear velocity of the metal conveying mesh belt and finally realizing the thickness accurate control in the forming process of the optical glass strip.

8. The control method according to claim 7, wherein the laser range finder is vertically installed right above the forming mold, the measuring light spot is projected on the surface of the formed molten glass through the measuring through hole arranged on the mold cover plate, the measured distance between the bottom surface of the range finder window and the upper surface of the mold bottom plate is larger than the actual value under the influence of the refractive index of the glass, the programmable controller converts the forming thickness value of the glass strip by adopting the following formula to directly obtain the numerical value representing the forming thickness, and the numerical value is expressed by adopting the following formula:

S = (L -) + λ·

= （S - L）/ (λ- 1)

wherein S is a distance measurement value from the bottom surface of a window of the laser range finder to the upper surface of the bottom plate of the forming die;

l is the real value of the distance from the bottom surface of the window of the laser range finder to the upper surface of the bottom plate of the forming die;

lambda is the refractive index corresponding to the optical glass;

the value is converted into the forming thickness of the optical glass strip.

9. The control method according to claim 7, wherein the laser range finder is obliquely arranged above the side part of the forming die, the measuring light spot is projected on an intersection line of molten glass and a die back plate by bypassing the sealing area of the forming die, and under the refraction action of the transparent molten glass, when the forming thickness is changed, the area of an effective light spot falling on the die back plate is changed, the output detection value of the laser range finder is changed, and according to the measuring principle, the programmable controller indirectly obtains the numerical quantity which is used for representing the forming thickness and participates in the control.

Technical Field

The invention relates to the technical field of optical glass strip material forming thickness control, in particular to a device and a method for controlling the thickness of a fluorophosphate optical glass strip material.

Background

The fluorophosphate optical glass is a novel excellent optical material with low dispersion and low refraction, and is widely applied to digital cameras, mobile phones, high-definition security systems and the like at present. When the optical glass strip containing fluorine and fluorophosphate is formed, if the surface of the glass liquid is directly exposed in the air, the components of the high-temperature glass liquid are seriously volatilized, a large number of surface stripes are caused, and the yield of products is seriously influenced. In addition, as the material of the forming die is nodular cast iron, the forming die is extremely easy to be corroded by fluorophosphate glass under high temperature. Therefore, the forming mold of the fluorophosphate optical glass strip is generally designed to be relatively sealed, and inert gas is filled from the cover plate to protect and cool the surface of the molten glass in the mold, so as to control the volatilization amount of the surface of the molten glass and improve the surface stripes of the glass strip. In addition, since fluorophosphate glass generally has the characteristics of low softening point and large viscosity change along with temperature, although the pipe diameter of the discharging platinum pipe is designed to be thin, the discharging amount still fluctuates greatly, so that the thickness of the glass strip is difficult to control.

The most common method for controlling the thickness of the formed common optical glass strip is manual real-time visual inspection, and the speed of the traction mechanism is manually adjusted according to the height change of the surface of molten glass, so that the method is simple and feasible although the effect is poor. An automatic control method, for example, a system and method for controlling the thickness of glass strip as disclosed in chinese patent No. ZL 201510633834.0, wherein a detecting device is contacted with the surface of the formed glass by a roller, thereby detecting and controlling the thickness of the glass strip. As the viscosity of the molten glass is difficult to control in the forming process of the fluorophosphate glass strip, if manual control is adopted, the control effect is still poor although the control frequency is increased. The automatic control device is not effective due to the influence of the relatively sealed environmental conditions of the molding area and the strong corrosiveness of the fluorophosphate glass liquid and its volatile substances under the high-temperature condition.

Disclosure of Invention

The invention aims to solve the technical problem of how to realize the accurate control of the forming thickness of the fluorophosphate optical glass strip material.

The technical scheme of the control device is that the device for controlling the forming thickness of the fluorophosphate optical glass strip comprises a discharging unit, a forming unit and a traction unit, wherein the discharging unit consists of a platinum discharging pipe welded at the bottom of a working pot of a smelting furnace and a temperature control system thereof, the forming unit consists of a mould bottom plate, a left side plate and a right side plate of a mould, a rear baffle of the mould and a mould cover plate, the mould cover plate is a U-shaped hollow welding part and comprises a top plate, a front sealing plate and a rear sealing plate, the front sealing plate and the rear sealing plate are arranged above the mould, so that a relative sealing structure is formed in a mould forming area, and the traction unit consists of a metal conveying mesh belt, a driving roller, a driven roller:

the detection unit consists of a laser range finder and a mounting bracket thereof and is used for detecting the change of the liquid level height of the molten glass near the discharge pipe orifice in the forming die in the cover plate through the measurement through hole;

and the control unit consists of a programmable controller and a frequency converter, is respectively connected with the laser range finder and the variable frequency motor, and is used for correcting the output frequency of the frequency converter based on the comparison between the detection value obtained from the laser range finder and a preset value, so that the linear velocity of the metal conveying net belt is adjusted, and the thickness precision control in the optical glass strip forming process is finally realized.

In the scheme, the measuring object of the laser range finder is an opaque object, the measuring range is 1000mm-5000mm, the measuring precision is 0.01mm, and during normal use, the measuring light spot (7) projected on the surface of the measuring object is a square with the side length of 8mm-12 mm.

In the scheme, the programmable controller comprises a human-computer data interaction platform, a standard MODBUS communication component and an analog output component; the frequency converter is set to a corresponding analog input control mode.

In the above scheme, laser range finder according to site environment or technological requirement, install perpendicularly in the shaping unit top, set up the measurement through-hole on the apron, link to each other with programmable controller's standard MODBUS communication subassembly through the communication data line, programmable controller's analog quantity output subassembly passes through the output signal line and links to each other with the analog quantity control terminal of converter, the power output end of converter passes through the power cord and links to each other with inverter motor.

In the above scheme, the laser range finder is obliquely installed above the forming unit according to the field environment or the process requirements, and is connected with a standard MODBUS communication component of the programmable controller through a communication data line, an analog output component of the programmable controller is connected with an analog control terminal of the frequency converter through an output signal line, and a power output end of the frequency converter is connected with the variable frequency motor through a power line.

The technical scheme of the control method is that the method for controlling the forming thickness of the fluorophosphate optical glass strip is characterized by comprising a discharging unit, a forming unit, a traction unit, a detection unit and a control unit; the discharging unit consists of a platinum discharging pipe and a temperature control system thereof; the forming unit consists of a die bottom plate, a left side plate, a right side plate, a rear baffle and a cover plate; the traction unit consists of a metal conveying mesh belt, driving and driven rollers and a variable frequency motor; the detection unit consists of a laser range finder, a mounting bracket thereof and a measurement through hole arranged on the cover plate; the control unit consists of a programmable controller and a frequency converter and is respectively connected with the laser range finder and the variable frequency motor;

the laser range finder monitors the change of the liquid level height of the molten glass near the discharge pipe orifice in the forming die in the cover plate in real time through the measuring through hole;

based on the detection value obtained from the laser range finder, the output frequency of the frequency converter is corrected by comparing with a preset value, so that the linear velocity of the metal conveying mesh belt is adjusted, and the thickness precision control in the optical glass strip forming process is finally realized.

In the scheme, a measuring object of the laser range finder is an opaque object, the measuring range is 1000mm-5000mm, the measuring precision is 0.01mm, and a measuring spot (7) projected on the surface of the measuring object is a square with the side length of 8mm-12mm when the laser range finder is normally used; the programmable controller comprises a human-computer data interaction platform, a standard MODBUS communication component and an analog output component; the frequency converter is set to a corresponding analog quantity input control mode;

the laser range finder monitors the change of the liquid level height of the molten glass near the discharge pipe orifice in the forming die in the cover plate in real time through the measuring through hole, and transmits the detected distance data to a programmable controller in the control unit in an MODBUS communication mode;

based on the distance data obtained from the laser range finder, the programmable controller converts effective data representing the forming thickness change of the glass strip through system operation, and inputs a 4mA-20mA analog signal for controlling the frequency output of the frequency converter to the frequency converter by adopting PID regulation control according to the comparison relation between the effective data and preset data, so as to correct the output frequency of the frequency converter, thereby the linear speed of the metal conveying mesh belt finally realizes the thickness accurate control in the forming process of the optical glass strip.

In the above scheme, laser range finder installs directly over forming die perpendicularly, and the measurement facula is thrown on shaping glass liquid surface through the measurement through-hole that sets up on the mould apron, receives the influence of glass refracting index, and the distance value of the distancer window bottom surface that obtains of measurement and mould bottom plate upper surface is greater than the true value, and programmable controller adopts following formula to convert the shaping thickness value of glass strip material, directly reachs the numerical value quantity of sign shaping thickness, and this numerical value quantity adopts following formula to express:

S = (L -) + λ·

= （S - L）/ (λ- 1)

wherein S is a distance measurement value from the bottom surface of a window of the laser range finder to the upper surface of the bottom plate of the forming die;

l is the real value of the distance from the bottom surface of the window of the laser range finder to the upper surface of the bottom plate of the forming die;

lambda is the refractive index corresponding to the optical glass;

the value is converted into the forming thickness of the optical glass strip.

In the above scheme, the laser range finder is obliquely installed above the side part of the forming die, the measuring light spot is projected on the intersection line of the glass liquid and the die rear baffle plate by bypassing the sealing area of the forming die, under the refraction action of the transparent glass liquid, when the forming thickness changes, the area of the effective light spot falling on the die rear baffle plate changes, the output detection value of the laser range finder also changes accordingly, and according to the measuring principle, the programmable controller indirectly obtains the numerical quantity of the characterization forming thickness participating in control.

Drawings

Fig. 1 is an overall structural view of a molding thickness control apparatus according to an embodiment of the present invention.

Fig. 2 is a specific structural diagram of a molding thickness measuring method according to an embodiment of the present invention.

Detailed Description

Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements.

In the following detailed description, numerous specific details are set forth in order to provide a better understanding of the invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, methods, procedures, components, and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present invention.

As shown in fig. 1 and 2, the fluorophosphate optical glass strip forming thickness control device comprises a discharging unit, a forming unit, a traction unit, a detection unit and a control unit.

The feeding unit consists of a platinum discharging pipe 1 welded at the bottom of a working pot of the smelting furnace and a temperature control system thereof, and belongs to the prior art. The temperature control system is connected with the platinum discharging pipe through a temperature detecting element and an electric power adjusting element, and the viscosity of the molten glass in the pipe is controlled by controlling the temperature of each section of the platinum discharging pipe and is kept in the range required by the forming process.

The molding unit consists of a mold bottom plate 24, a mold left side plate 21, a mold right side plate 22, a mold rear baffle plate 23 and a mold cover plate. For ease of molding, the mold back plate 23 is angled at a specified value (typically 120-150 degrees) from the face of the mold bottom plate 24. The cover plate is a U-shaped hollow weldment comprising a top plate 31, a front closure plate 32 and a rear closure plate 34, and is mounted above the mold so that the mold forming area forms a relatively sealed structure. And the inner surface of the top plate of the mold is provided with an air outlet, and inert gas for protection and cooling is filled into the surface of the formed molten glass. In order to facilitate the detection of the molding thickness in the vertical direction, a measurement through hole 33 is provided at a corresponding position on the top plate 31 as needed.

The traction unit mainly comprises a metal conveying mesh belt 51, a driving roller 52, a driven roller 52 and a variable frequency motor 53. The function of the device is to continuously draw the formed glass strip 4 to an annealing area and a blanking area. The thickness of the glass strand 4 formed while the viscosity of the molten glass in the platinum tapping pipe 1 was kept within the process range was determined by the line speed of drawing with the metal mesh belt 51.

The detection unit is composed of a laser range finder 6 obliquely installed above the molding unit or a laser range finder 61 vertically installed above the molding unit and a mounting bracket thereof. The measuring objects of the laser range finders 6 and 61 are opaque objects, the measuring range is 1000mm-5000mm, the measuring precision is 0.01mm, and the measuring light spot 7 projected on the surface of the measuring object is a square with the side length of 8mm-12mm in normal use.

The control unit consists of a programmable controller 8 and a frequency converter 9. The programmable controller 8 has the functions of man-machine data interaction, standard MODBUS communication, analog quantity output and the like. The frequency converter 9 is set to the corresponding analog input control mode.

The laser range finders 6 and 61 in the detection unit are vertically or obliquely arranged above the forming unit according to the field environment or process requirements and are connected with a communication component of a programmable controller 8 in the control unit through a communication data line. The analog output component of the programmable controller 8 is connected with the analog control terminal of the frequency converter 9 through an output signal wire, and the power output end of the frequency converter 9 is connected with the variable frequency motor 53 in the traction unit through a power wire.

The invention also provides a fluorophosphate optical glass strip forming thickness control method, the thickness control device comprises a discharge unit, a forming unit, a traction unit, a detection unit and a control unit, and is characterized in that the control method comprises the steps that a laser range finder 6 or 61 monitors the change of the liquid level height of molten glass on a forming die and near the pipe orifice of a discharge pipe 1 in real time, the detected distance data is transmitted to a programmable controller 8 in the control unit in an MODBUS communication mode, the programmable controller 8 converts effective data representing the thickness change of the glass strip 4 through system operation, and inputs a 4mA-20mA analog signal for controlling the frequency output size of the frequency to a frequency converter 9 according to the comparison relation between the effective data and preset data by adopting PID regulation control to correct the output frequency of the frequency converter 9, thereby adjusting the linear speed of the conveyor belt 51 in the drawing unit and finally realizing the thickness accurate control in the forming process of the optical glass strip 4.

As shown in fig. 2 or fig. 1, the laser distance measuring instrument 6 or 61 can be installed in different ways according to the process requirements and environmental conditions for forming different grades of optical glass, and the invention can be implemented in different ways according to the measurement principle.