JP3912645B2 - Glass tube measurement method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a measurement method for measuring the concentricity of a glass tube using a laser beam.
[0002]
[Prior art]
Conventionally, the measurement of the concentricity of a glass tube is performed as follows. As shown in FIG. 5, a red laser beam 2 having a wavelength of about 680 nm emitted from a laser light source 4 of a laser measuring device 3 is deflected by a deflecting means 5 made of a reflector that is rotationally driven or reciprocally attached with a reflecting mirror. The deflected laser beam 2 is deflected in a predetermined cycle, is made parallel by the collimator lens 6 and is scanned at right angles to the axial direction of the glass tube 1, and the laser beam 2 transmitted through the glass tube 1 is sensor 8 by the condenser lens 7. The sensor 8 detects the change in the amount of the laser beam 2 generated at both edges of the outer periphery 1a and the inner hole 1b of the glass tube 1 and converts it into a voltage signal S1. In the processing unit 9, the falling edge R1, the signal peaks P1, P2, P3, and the rising edge R2 of the voltage signal S1 of the portion scanned with the glass tube 1 intersect with the predetermined signal level V1, and the intersections {circle around (1)} to {circle around (8)}. Occurs. Of these intersection points, intersection points (1) and (8) correspond to edge portions 1d and 1c of outer periphery 1a, and intersection points (3) and (6) correspond to edge portions 1e and 1f of inner hole 1b, respectively. , The detection time of the intersection point (1) and the detection time of the intersection point (8) are averaged to calculate the time to corresponding to the center position 1h of both edge portions 1c, 1d of the outer periphery 1a, and the intersection point (3) obtained almost simultaneously The time ti corresponding to the center position 1i of both edge portions 1e and 1f of the inner hole 1b is calculated by averaging the detection time of ▼ and the detection time of the intersection (6), and the time required from time to to time ti is calculated. In terms of length, the distance from the center position 1h of the outer periphery 1a of the glass tube 1 to the center position 1i of the inner hole 1b is calculated. By performing such measurement processing in a plurality of directions with respect to the outer periphery 1a of the glass tube 1, the concentricity of the glass tube 1 is obtained. The output concentricity value is displayed on the display unit 10.
[0003]
[Problems to be solved by the invention]
However, when the light transmittance of the glass tube changes greatly, as shown in FIG. 5C, the light amount of the laser beam 2a transmitted through the central portion of the glass tube 1 becomes small, and this change in the light amount is detected by the sensor 8. Then, when converted into the electric signal S1a, the signal peak P2 becomes lower than the signal level V1, and the intersections (4) and (5) do not occur, and the sixth one corresponding to one edge 1d of the outer periphery 1a originally. The intersection point (8) at which the signal level V1 is reached is erroneously detected as the intersection point (6) corresponding to the edge portion 1f of the inner hole 1b, and the time ti corresponding to the center position 1i of the inner hole 1b of the glass tube 1 is detected. There is a problem that cannot be calculated.
[0004]
Further, when the glass tube 1 is made of crystallized glass exhibiting milky white color and the visible light transmittance is very low, scanning with the conventional red laser beam 2 having a wavelength of about 680 nm results in the laser beam 2a and the like. The signal peaks P1, P2, and P3 of the voltage signal S1 that is not sufficiently transmitted through the glass tube 1 and scanned through the glass tube 1 are lowered, and the two edge portions 1e and 1f of the inner hole 1b are reduced as in FIG. There is a problem that the time ti corresponding to the center position 1i of the inner hole 1b cannot be calculated because it cannot be detected.
[0005]
An object of this invention is to provide the measuring method of the concentricity of the glass tube which solved the said conventional problem.
[0006]
[Means for Solving the Problems]
The measuring method of the glass tube according to the present invention is such that the laser beam is scanned at right angles to the axial direction of the glass tube and in a plurality of directions with respect to the outer periphery of the glass tube, and both edges of the outer periphery and inner hole of the glass tube The sensor detects the change in the amount of laser light generated at the part and converts it into an electrical signal, and detects both the edge part of the outer periphery and the inner hole of the glass tube for the position where the electrical signal becomes a predetermined signal level, Measurement of the glass tube that calculates the center position of each of the outer periphery and the inner hole from the position of one edge and the other edge, and measures the concentricity from the distance between the center position of the outer periphery and the center position of the inner hole in the method, the signal level detecting both edges of the bore by adjusting the measurement position of the light amount as a reference laser beam transmitted through the glass tube in accordance with the outer diameter of the glass tube, moth And adjusting in accordance with the amount of the laser beam transmitted through the scan line.
[0008]
Furthermore, the glass tube measuring method of the present invention is characterized in that the glass tube is made of crystallized glass that transmits light in the infrared region, and the wavelength of the laser beam that passes through the glass tube is 1000 nm or more.
[0009]
[Action]
According to the method for measuring a glass tube of the present invention, the signal level for detecting both edge portions of the inner hole is adjusted according to the amount of laser light transmitted through the glass tube. There is no need to manually adjust the signal level for the laser beam to detect both edges of the inner hole every time the transmittance changes, and the center position of the inner hole of the glass tube with different light transmittance for the laser beam can be accurately determined. Can be measured.
[0010]
Further, according to the method for measuring a glass tube of the present invention, when adjusting the signal level for detecting the edge portion of the inner hole, the measurement position of the light quantity serving as a reference of the laser beam transmitted through the glass tube is set to the outer diameter of the glass tube. Because it adjusts according to the dimensions, it is not necessary to manually adjust the measurement position of the amount of light that becomes the reference of the laser beam transmitted through the glass tube, which has been done each time the outer diameter dimension of the glass tube changes. It is possible to accurately measure the center position of the inner holes of the glass tubes having different values.
[0011]
In addition, according to the method for measuring a glass tube of the present invention, the glass tube is made of crystallized glass that transmits light in the infrared region, and the wavelength of the laser beam transmitted through the glass tube is 1000 nm or more, and thus cannot be measured conventionally. The center position of the inner hole of the glass tube made of crystallized glass can be accurately measured.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B are explanatory diagrams of an embodiment of the present invention, in which FIG. 1A is a conceptual diagram of a laser measuring device, and FIG. 1B is an explanatory diagram of a laser beam that scans a glass tube. In this figure, 1 is a glass tube, 2 is a laser beam, 3 is a laser measuring device, 4 is a laser light source, 5 is a deflecting means for the laser beam 2, 6 is a collimator lens for the laser beam 2, and 7 is a laser beam 2. 8 is a sensor that converts the laser beam 2 into a voltage signal S1, 9 is a center position 1h of the outer periphery 1a of the glass tube 1 and a center position 1i of the inner hole 1b. Reference numeral 10 denotes a processing unit for converting to a display unit 10 for displaying the concentricity of the glass tube 1 calculated by the processing unit 9. FIG. 2 is an explanatory diagram of the inside of the processing unit 9 when the light transmittance of the glass tube 1 changes. FIG. 3 is an explanatory diagram when the outer diameter of the glass tube 1 changes. FIG. 4 shows a laser beam that has adjusting means 11 for adjusting the measurement position 1g of the light amount of the laser beam 2 transmitted through the glass tube 1 according to the outer diameter of the glass tube 1 and that transmits the measurement position 1g of the glass tube 1. 2 is an explanatory diagram of a circuit 9a of a processing unit 9 that detects a VP value that changes according to a light quantity of 2 and adjusts a signal level V2. FIG.
[0013]
As shown in FIG. 1, a laser measuring instrument 3 used in an embodiment of the present invention includes a laser light source 4 that emits a laser beam 2 having a wavelength of 1550 nm using a laser diode, and a reflector with a reflecting mirror attached thereto. The deflecting means 5 that reflects the laser beam 2 emitted from the laser light source 4 by rotating or vibrating, and the laser beam 2 deflected by the deflecting means 5 are parallel and scanned at right angles to the axial direction of the glass tube 1. A collimator lens 6, a condensing lens 7 for condensing the laser beam 2 transmitted through the glass tube 1, a sensor 8 for converting the laser beam 2 collected by the condensing lens 7 into a voltage signal S1, and the voltage signal S1 are signals. Both edges 1c and 1d of the outer periphery 1a are detected at the point where the level is V1, and each detection time is averaged to correspond to the center position 1h of the outer periphery 1a. The time to is calculated, and both edge portions 1e and 1f of the inner hole 1b are detected at the point where the voltage signal S1 becomes the signal level V2, and each detection time is averaged to correspond to the center position 1i of the inner hole 1b. The time ti is calculated, the difference Δt between the time to and the time ti is converted into a distance K having a unit of length using a high-resolution clock pulse or the like, and a series of measurement processes are performed on the entire outer periphery 1a of the glass tube 1 The processing unit 9 that calculates the maximum movement distance of the center position 1i with respect to the center position 1h as the concentricity of the glass tube 1 and the concentricity of the glass tube 1 converted by the processing unit 9 are displayed. And display unit 10. The laser measuring device 3 has the above-described configuration, and rotates the glass tube 1 by positioning the glass tube 1 within the scanning range of the laser beam 2 so that the axial direction of the glass tube 1 is perpendicular to the scanning direction of the laser beam 2 (illustrated). The data of 10,000 points is collected by rotating the glass tube 1 twice at a rotational speed of 12 rpm using the (not shown).
[0014]
In the measuring method of the glass tube of the present invention, as shown in FIG. 1, when the measurement position of the light quantity serving as a reference of the laser beam 2 transmitted through the glass tube 1 is set to the measurement position 1g having the largest light quantity, it corresponds to the measurement position 1g. The voltage of the voltage signal S1 is VP. This voltage VP changes in conjunction with the light transmittance of the glass tube 1. When the signal level V2 is set to a constant ratio between 40% and 60% with respect to the voltage VP, for example, 50%, the signal level V2 and the voltage signal S1 are stably generated at the intersections (2) to (7). Therefore, even when the light transmittance of the glass tube 1 changes, both edge portions 1e and 1f of the inner hole 1b can be detected stably, and an accurate time ti corresponding to the center position 1i can be calculated. become. For example, as shown in FIG. 2, when the light transmittance of the glass tube 1 decreases and the voltage signal S1 changes like the voltage signal S1a, the voltage VP changes to the voltage VP ′, and the signal level is interlocked therewith. Since V2 is set to the signal level V2 ′, the signal level V2 ′ and the voltage signal S1a stably generate the intersections {circle around (2)} to {circle around (7)}, and the time ti corresponding to the center position 1i of the inner hole 1b is set. Can be calculated.
[0015]
However, when the measurement position 1g of the light quantity that becomes the reference of the laser beam 2 transmitted through the glass tube is fixed, as shown in FIG. 3, when the outer diameter dimension of the glass tube 1 is within a predetermined measurement range D1, the voltage signal Although the inner diameter can be measured by crossing S1 and the signal level V2, the following problems arise when the outer diameter becomes larger and exceeds the measuring range D1 and becomes the size of the glass tube 20. .
[0016]
When the outer diameter is increased, the voltage signal S1 of the glass tube 1 changes to the voltage signal S1b of the glass tube 20, and the light amount of the laser beam is reduced at the measurement position 1g where the light amount measurement position is fixed. If the signal level V2 ′ is determined at a constant ratio with respect to the corresponding voltage VP ′, the signal level V2 ′ does not intersect with the signal S1b, and the center position 1i of the inner hole 1b cannot be calculated. Therefore, it is necessary to expand the measurement range to D2 and adjust the light quantity measurement position from 1g to 1j. On the other hand, even when the outer diameter of the glass tube becomes very small with respect to the set measurement range, it is necessary to adjust the measurement range to the optimum measurement range and the optimum measurement position of the light amount.
[0017]
According to a preferred method for measuring a glass tube of the present invention, when adjusting the signal level V2 for detecting both edge portions 1e and 1f of the inner hole, the measurement position of the amount of light serving as a reference of the laser beam 2 transmitted through the glass tube is determined. It adjusts according to the dimension of the outer diameter.
[0018]
Next, when measuring the concentricity of the glass tube 1, first, as shown in FIG. 1, the axial direction of the glass tube 1 is perpendicular to the scanning direction of the laser beam 2 within the scanning range of the laser beam 2. Position to be.
[0019]
Next, when the change in the light quantity of the laser beam 2 generated at both edge portions 1c and 1d of the outer periphery 1a of the glass tube 1 and both edge portions 1e and 1f of the inner hole 1b is detected by the sensor 8 and converted into the voltage signal S1, FIG. As shown in FIG. 4, the processing unit 9 transmits the voltage signal S1 through the glass tube 1 and has a waveform having a falling edge R1, a signal peak P1, a signal peak P2, a signal peak P3, and a rising edge R2. The falling points R1 and R2 of the voltage signal S1 and the signal level V1 intersect to generate intersections (1) and (8). This signal is waveform-shaped and output as a rectangular voltage signal S2, the rising time of the rectangular voltage signal S2 is the detection time t1 of the edge 1c of the outer periphery 1a, and the falling time of the voltage signal S2 is the edge. The detection time t2 of 1d is reached, and the time t1 corresponding to the center position 1h of the outer periphery 1a is calculated by averaging the time t1 and the time t2.
[0020]
Next, as the adjusting means 11 for adjusting the measurement position 1g of the light quantity of the laser beam 2 transmitted through the glass tube 1 according to the outer diameter of the glass tube 1, first, the falling time of the voltage signal S2 is a signal peak from t1. A time t3 at which P1 starts rising and a time t4 at which the signal peak P3 ends falling are set, and a rectangular voltage signal S3 is obtained by waveform shaping. Next, the voltage signal S1 is sampled by the voltage signal S3, the voltage signal S1 is differentiated in the range from the time t3 to the time t4, the position of the inflection point is specified, and the time when the signal peak P1 has the highest voltage tP is obtained. The position corresponding to this time tP is the light quantity measurement position 1g. For the measured voltage VP, the signal level V2 is set to, for example, 50% of the voltage VP, which always intersects the voltage signal S1 at the intersections (2) to (7).
[0021]
Next, the voltage signal S1 and the signal level V2 intersect to generate a signal having the intersections {circle around (2)} to {circle around (7)} to form a rectangular voltage signal S4. The voltage signal S4 is shaped to a rectangular shape. A voltage signal S5 having a shape is output, and the detection time t5 of the intersection point (3) corresponding to the edge portion 1e of the inner hole 1b and the detection time t6 of the intersection point (6) corresponding to the edge portion 1f are averaged. A time ti corresponding to the center position 1i of 1b is calculated.
[0022]
Next, the time Δt from the time to corresponding to the center position 1h of the outer periphery 1a of the glass tube 1 to the time ti corresponding to the center position 1i of the inner hole 1b is converted into a length using a high resolution clock pulse or the like. The distance K of the center position 1i of the inner hole 1b is calculated with reference to the center position 1h of the outer periphery 1a in one measurement direction of the glass tube 1. A series of measurement processing is performed in a range in which the time ti at the center position 1i is delayed with respect to the time to at the center position 1h by rotating the glass tube 1 about the tube axis twice and measuring 10,000 times in the circumferential direction. The positive maximum value of the distance K and the negative minimum value of the distance K in the range where the time ti is earlier than the time to are detected, and the difference is calculated as the concentricity of the glass tube 1. The calculated concentricity is output to the display unit 10 and displayed.
[0023]
As described above, the glass tubes having different light transmittances in the range of 80 to 90% with respect to the laser beam 2, and the outer diameter is 1.0 to 5.0 mm and the inner diameter is 0.05 to 0.00. The concentricity of glass tubes 1 having different dimensions in the range of 5 mm was measured.
[0024]
In addition, the glass tube 1 is made of crystallized glass that is milky white and has a thickness of 1 mm and transmits 5% of light with a wavelength of 900 nm in the infrared region, 75% of light with a wavelength of 1500 nm, and 80% or more of light with a wavelength of 1600 nm. The laser light source 4 was scanned with a laser beam 2 having a wavelength of 1550 nm using a laser diode, and the concentricity of the glass tube 1 was measured.
[0025]
In the method for measuring a glass tube according to the embodiment of the present invention, glass tubes having different light transmittances in the range of 80 to 90% with respect to the laser beam in an environment of 20 ± 5 ° C., the outer diameter is The concentricity of glass tubes having different dimensions within a range of 1.0 to 5.0 mm and an inner diameter of 0.1 to 0.5 mm, and a glass tube made of crystallized glass that transmits light in the infrared region is determined in the optical axis direction. Within the measurement range of ± 0.2 mm, the linearity was ± 0.1 μm and the reproducibility was within ± 0.5 μm.
[0026]
【The invention's effect】
According to the method for measuring a glass tube of the present invention, a glass tube having a different light transmittance with respect to a laser beam, a glass tube having a different outer diameter, and a crystallized glass that hardly transmits visible light but transmits light in the infrared region. This provides a practically excellent effect capable of accurately measuring the concentricity of each glass tube.
[Brief description of the drawings]
FIGS. 1A and 1B are explanatory views of a glass tube measuring method according to the present invention, in which FIG. 1A is a conceptual diagram of a laser measuring apparatus, and FIG.
FIG. 2 is an explanatory diagram of the present invention, illustrating an output pattern of a processing unit when the light transmittance of a glass tube changes.
FIG. 3 is an explanatory diagram of the present invention, illustrating the necessity of adjusting the measurement position of the amount of light serving as a reference of a laser beam according to the outer diameter.
4A and 4B are explanatory diagrams of a processing unit, where FIG. 4A is a conceptual circuit diagram of signal processing, and FIG. 4B is an explanatory diagram of a signal pattern.
5A and 5B are explanatory diagrams of a conventional glass tube measuring method, wherein FIG. 5A is a conceptual diagram of a laser measuring device, FIG. 5B is an explanatory diagram of a laser beam that scans the glass tube, and FIG. Explanatory drawing of the output pattern of a part.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,20 Glass tube 1a Outer periphery 1b Inner hole 1c, 1d, 1e, 1f Edge part 1h, 1i Center position 1g, 1j Measurement position 2 Laser beam 3 Laser measuring device 4 Laser light source 5 Deflection means 6 Collimator lens 7 Condensing lens 8 Sensor 9 processing section 9a circuit 10 display section 11 adjusting means D1, D2 measurement ranges P1, P2, P3 signal peaks S1, S1a, S1b, S2, S3, S4, S5 voltage signals V1, V2, V2 ′ signal level

Claims (2)

The laser beam is scanned at right angles to the axial direction of the glass tube and in multiple directions with respect to the outer periphery of the glass tube, and changes in the amount of laser beam generated at both edges of the outer periphery and inner hole of the glass tube are detected by a sensor. Detects and converts to an electrical signal, obtains a position where the electrical signal reaches a predetermined signal level, detects both the outer edge and the inner hole of the glass tube, and detects the position of one edge and the other edge In the measuring method of the glass tube , which calculates the concentricity from the distance between the center position of the outer periphery and the center position of the inner hole, the center position of each of the outer periphery and the inner hole is calculated from the position of the signal level, the laser beam transmitted through the glass tube light amount detecting both edges of the bore by adjusting in accordance with the outer diameter of the glass tube the light amount measurement position of the Measuring method of the glass tube, characterized in that to adjust accordingly. It consists crystallized glass glass tube which transmits light in the infrared region, the measuring method of the glass tube according to claim 1 or claim 1 wavelength of the laser beam transmitted through the glass tube, characterized in that at 1000nm or more.

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