JPH0971432A - Outer diameter measuring device - Google Patents

Abstract

(57) [Abstract] [Problem] It has been difficult to perform simultaneous multipoint measurement with conventional outer diameter measuring devices. According to a first aspect of the present invention, a light projecting section (2) for projecting a wide light toward an object to be measured (1) and a light projecting section (2) sandwiching the object to be measured (1).
An outer diameter that is arranged at a position opposite to that of the light receiving unit 3 that receives light that is not blocked by the DUT 1 and that determines the outer diameter of the DUT 1 from the light received by the light receiving unit 3. The measuring device includes a movable mechanism 4 that reciprocally moves the light projecting unit 2 and the light receiving unit 3 along the longitudinal direction of the DUT 1, and a position detecting mechanism 5 that detects the positions of the light projecting unit 2 and the light receiving unit 3. Provided. According to a second aspect of the present invention, the apparatus detects the moving positions of the light projecting unit 2 and the light receiving unit 3, and enables the outer diameter measurement at two or more positions of the meniscus portion of the DUT 1 in the moving direction. The control circuit 6 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer diameter measuring device for measuring the outer diameter of various articles. For example, when the rod-shaped glass serving as the core of an optical fiber is heated and stretched to reduce the diameter, It is suitable for use in measuring the outer diameter of the meniscus portion of the rod-shaped glass.

[0002]

2. Description of the Related Art For example, as shown in FIG. 6, a glass base material A is gradually stretched (drawn) while being heated in an electric furnace and reduced to a predetermined outer diameter to form a core of an optical fiber. When manufacturing the reform core B, not only is the glass base material A drawn, but the glass base material A is sent in the drawing direction in accordance with the drawing amount. In this case, in order to make the outer diameter of the preform core B constant, it is necessary to make the outer diameter of the solidification point D constant in the meniscus portion C which is gradually thinned by drawing. In this case, conventionally, the outer diameter of any one point of the meniscus portion C was precisely measured, and the drawing amount and the feed amount of the base material were controlled so that the outer diameter was always constant.

Conventionally, an outer diameter measuring device has been used to measure the outer diameter of a rod-shaped or tubular object to be measured.
An example of the outer diameter measuring device is shown in FIG.
This device includes a light projecting section E for projecting a wide range of light in the outer diameter direction of the measured object A (glass base material) A, and a light projecting section sandwiching the measured object A. And a light receiving section F which is arranged on the opposite side of E and receives light which is not blocked by the object to be measured A. With this device, the width G of the light blocked by the object A to be measured can be detected to determine the outer diameter of the object A to be measured. In this device, the light projecting section E
The position of the light receiving part F is fixed at a predetermined position.

Further, an outer diameter measuring device having the same structure as that shown in FIG. 6, in which the light projecting portion E and the light receiving portion F in the same figure can be moved slowly along the longitudinal direction of the object A to be measured. There is also. This device includes the light projecting section E and the light receiving section F.
Is slidably attached to a guide (not shown) arranged along the longitudinal direction of the object to be measured A, and is moved outside the object to be measured A while moving in the longitudinal direction of the object to be measured A by an appropriate slide mechanism. The diameter can be measured.

[0005]

Among the above-mentioned outer diameter measuring devices, the one shown in FIG. 6 has the following problems. . Since the outer diameter of the object A to be measured can be measured at only one place, highly accurate measured values cannot be obtained. . In order to measure the outer diameter of the object to be measured A at multiple points in the longitudinal direction of the object to be measured A, the outer diameter measuring device itself is moved, or a large number of similar measuring devices are arranged along the longitudinal direction of the object to be measured A. I have to do it. However, in the former case, a separate movable mechanism must be provided to move the outer diameter measuring device in millimeters or micro units, and in order to grasp at which position the outer diameter measuring device was measured, the outer diameter measuring device itself It was necessary to accurately grasp the position of, and it was difficult to measure with high accuracy. In the latter case, it is physically difficult to arrange the outer diameter measuring devices at intervals of millimeters because the outer diameter measuring devices are in contact with each other or the installation place cannot be secured. It was difficult to measure the outer diameter of the measurement object A at multiple points in the longitudinal direction.

[0006] In the case where the outer diameter of the object A to be measured continuously changes in the longitudinal direction and changes with time as in the step of reducing the diameter of the glass base material, the outer diameter of the object A to be measured is measured at substantially the same time. It is desired that such simultaneous multi-point measurement be difficult even if any of the above multi-point measurement methods is used.

[0007] Even in the case where the light projecting portion E and the light receiving portion F are capable of moving slowly in the longitudinal direction of the DUT A, the outer diameter of the DUT A continuously changes in the longitudinal direction and changes with time. In such a case, it is not effective because simultaneous multipoint measurement is difficult.

An object of the present invention is to provide an outer diameter measuring device capable of measuring the outer diameter of an object to be measured at multiple points along the longitudinal direction thereof, and capable of reliably performing such multipoint measurement at a predetermined position. To do.

[0009]

As shown in FIG. 1, the outer diameter measuring device according to the first aspect of the present invention projects a light beam wider than its outer diameter toward the object to be measured 1. 2 and a light receiving section 3 which is arranged at a position opposite to the light projecting section 2 with the DUT 1 interposed therebetween and which receives light which is not blocked by the DUT 1, from the light received by the light receiving section 3. In an outer diameter measuring device configured to determine the outer diameter of a DUT 1, the light emitting unit 2 and the light receiving unit 3 for measuring the outer diameter of a meniscus portion of the DUT 1 are provided in the device. A movable mechanism 4 that reciprocates along the longitudinal direction and a position detection mechanism 5 that detects the positions of the light projector 2 and the light receiver 3 that reciprocate are provided.

As shown in FIG. 5, the outer diameter measuring apparatus according to the second aspect of the present invention is the same as the outer diameter measuring apparatus according to the first aspect.
The moving positions of the reciprocating light projecting unit 2 and the light receiving unit 3 are detected, and the meniscus portion 2 of the DUT 1 in the moving direction is detected.
The control circuit 6 is provided to enable the outer diameter to be measured at more than one place.

[0011]

In the outer diameter measuring apparatus according to the first aspect of the present invention, the light projecting portion 2 for projecting light wider than the outer diameter toward the object to be measured 1 and the object 1 to be measured are projected. The light receiving unit 3 is arranged at a position opposite to the unit 2 and receives the light not blocked by the DUT 1, and the outer diameter of the DUT 1 is obtained from the light received by the light receiving unit 3. In the outer diameter measuring device, a movable mechanism 4 that reciprocally moves the light projecting unit 2 and the light receiving unit 3 for measuring the outer diameter of the meniscus portion of the DUT 1 along the longitudinal direction of the DUT 1. Since the position detecting mechanism 5 for detecting the positions of the reciprocally movable light emitting unit 2 and the light receiving unit 3 is provided, the light emitting unit 2 reciprocally movable in the longitudinal direction of the DUT 1 by the movable mechanism 4 and The light receiving unit 3 can measure the outer diameter of the meniscus portion of the device under test 1 at multiple points and at the same time It is possible to detect an accurate measurement position of the position detection mechanism 5. Further, if the reciprocating movement of the light projecting portion 2 and the light receiving portion 3 by the movable mechanism 4 is made high speed, it is also possible to continuously measure the outer diameter of the DUT 1 which changes with time. Not the outer diameter measurement
It is possible to perform measurement close to shape measurement.

In the outer diameter measuring device according to the second aspect of the present invention, the outer diameter measuring device according to the first aspect detects the moving positions of the light projecting portion 2 and the light receiving portion 3 which reciprocate, and the moving direction thereof. Since the control circuit 6 capable of measuring the outer diameter at two or more positions of the meniscus portion of the DUT 1 is provided, the outer diameter at the desired position of the meniscus portion of the DUT 1 should be measured. You can

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 An embodiment of the outer diameter measuring device of the present invention will be described in detail with reference to FIG. Reference numeral 1 shown in FIG. 1 is an object to be measured, and here is a bar-shaped glass (preform) that serves as a core of an optical fiber. A heater (not shown) is arranged at a position around the deformed (diameter-reduced) portion (meniscus portion) of the rod-shaped glass so as not to interfere with the light of the light projecting portion 2. , Supports on both ends of the glass rod (not shown)
By adjusting the amount of pushing and pulling of the glass rod, the diameter of the glass rod is reduced while being stretched.

Reference numeral 2 shown in FIG. 1 is a light projecting section. The light projecting section 2 outputs a band-shaped light which is wide in the outer diameter direction of the DUT 1 but is narrowed in the longitudinal direction. The band-shaped light has a width wider than the outer diameter D of the DUT 1, and the light radiated to the DUT 1 is not completely blocked by the DUT 1 and slightly escapes from both side surfaces thereof. The light receiving unit 3 described later receives light.

Reference numeral 3 shown in FIG. 1 is a light receiving portion. The light receiving section 3 receives the light emitted from the light projecting section 2, and is arranged on the opposite side of the light projecting section 2 with the DUT 1 interposed therebetween. The light receiving unit 3 is emitted from the light projecting unit 2 and the DUT 1 is measured.
Receives light passing through the sides of. The light amount of the light received by the light receiving section 3 reflects the outer diameter (diameter) D of the DUT 1 (when the outer diameter of the DUT 1 becomes large, the light receiving amount decreases and the outer diameter D becomes small. Then, the amount of received light is increased), and the outside diameter D of the DUT 1 can be obtained by processing this amount of received light by an appropriate circuit (not shown).
This measurement is performed at a predetermined time interval, or the light projecting unit 2 and the light receiving unit 3
Is carried out each time a predetermined amount is moved, and the outer diameter D of the DUT 1 is obtained each time.

The light projecting portion 2 and the light receiving portion 3 are the objects to be measured 1
Base plate 10 formed in a substantially U shape surrounding the outer periphery of the
The light emitting unit 2 and the light receiving unit 3 do not change their positional relationship even when the base plate 10 is driven up and down.

Reference numeral 4 shown in FIG. 1 is a movable mechanism that allows the base plate 10 to which the light projecting portion 2 and the light receiving portion 3 are attached to reciprocate only in the vertical direction. As shown in FIGS. 2 and 3, the movable mechanism 4 includes four guides (linear shaft 12a, linear bush 12b) 1 projecting upward from a box 11 that is substantially U-shaped like the base plate 10.
2 supports the base plate 10 so as to be slidable only in the vertical direction, and projects upward from the box 11 4
A push rod 13 of a book pushes or pulls the base plate 10 from below to reciprocate up and down.

Specifically, a motor (for example, an AC servomotor) 14 provided in the box 11 rotates a rotating body 15 attached to its rotating shaft in the direction of the arrow in the figure, and the rotating body 15 is rotated. The two left and right rods 16 connected to each other are moved in the directions of arrows a-b in the figure. Left and right two rods 1
6 swings the swing fittings 18 of the rotary shafts 19 arranged on the respective tip sides in the directions of arrows cd, thereby rotating the rotary shaft 19 in the directions of arrow ef. The rotating shaft 19 swings the second swing fitting 17 attached in the middle thereof in the arrow gh direction, and vertically drives the push rod 13 connected to the tip of each swing fitting 17. The motor 14 can also rotate at high speed, and in this case, the base plate 10 having the light projecting section 2 and the light receiving section 3 can be reciprocally moved at a considerably high speed, and the light of the light projecting section 2 can be measured. It is possible to perform measurement by accurately projecting the shape change of the DUT 1 in the longitudinal direction by projecting light so as to scan in the longitudinal direction of 1.

For example, as shown in FIG. 4, the movable mechanism 4 converts the rotational movement of the motor 14 into a reciprocating movement directly by the ball screw 20 and the ball nut 22, and the base plate 1
0 may be reciprocally movable in the vertical direction. In this case as well, it is desirable that the four positions supported by the guides 12 of the base plate 10 can be reciprocally moved in conjunction with each other, and therefore the rotation of the motor 14 is controlled by the bevel gear 22 and the rotary shaft 2.
By means of 3, the three ball screws 20 are distributed and transmitted to the other three ball screws 20 (only two ball screws 20 are shown), so that the four ball screws 20 are rotationally driven in synchronization with each other. It should be noted that the movable mechanism 4 in the outer diameter measuring device of the present invention may have a structure other than this.
It suffices that it be able to move vertically vertically without shaking.

Reference numeral 5 shown in FIG. 2 is a position detecting mechanism.
The position detecting mechanism 5 has a slit 30 as shown in FIG. 5 on the outer peripheral surface of the linear bush 12b of the guide 12.
A scale 31 is formed by engraving in millimeters. On the outer circumference of the linear bush 12b, there is a detection sensor 32 for detecting the slit of the slit 30, and a pulse output from the detection sensor 32 (slit 3 of the scale 31).
The pulse corresponding to 0) is counted by the counter 33.

In the present invention, the count value counted by the counter 33 is processed by the control circuit 6 shown in FIG. 5 to detect the moving position of the guide 12 and measure the outer diameter at a predetermined position. Specifically, the count value is set as an actual value of the positions of the light projecting unit 2 and the light receiving unit 3, and is displayed on the relative position indicator 34. Next, the data of the counter 33 is transferred to the comparator 35.
Is compared with the setting data of the upper position and the lower position set by the measurement position setting digital switch 36, and when they match, the data is output as a position signal of the outer diameter measuring device through the flip-flop circuit 37, and the light is emitted at each output. The data measured by the unit 2 and the light receiving unit 3 becomes the outer diameter of the DUT 1 at the upper and lower measurement positions set by the digital switch 36.

In FIG. 5, an intermediate point between the upper and lower portions is also set as a measurement position, and the intermediate position is also detected by comparison with the comparator 35. It is the outer diameter of the DUT 1 at the measurement position. With this configuration, the upper, lower, and lower three points of the DUT 1 can be measured as shown in FIG. 1B, and the outer diameter of the DUT 1 can be measured based on these data. Therefore, the measurement accuracy is improved. Reference numeral 38 in FIG. 5 is a measurement position detection unit, which has four detection units for the origin, upper part, middle part, and lower part. Each detection part 38 has a pair of an LED and a photocoupler, and an outer diameter measuring device is provided. When the origin, the upper portion, the intermediate portion, and the lower portion are reached, the LEDs at the respective positions are turned on. The light projecting unit 2 and the light receiving unit 3 that reciprocate are reset to the original position at the time of resetting.

[0023]

According to the outer diameter measuring device of claim 1 of the present invention,
It is possible to measure the outer diameter of the meniscus part of the object to be measured at multiple points with the light emitting part and the light receiving part that are reciprocally moved by the movable mechanism, and to detect the accurate measurement position at the time of multipoint measurement with the position detection mechanism. Therefore, the following effects can be obtained. . The outer diameter of each point of the meniscus can be obtained. . The average value of the outer diameter of each point of the meniscus can be obtained. . By using the average value, it is possible to eliminate the influence of defects such as small bumps and dents on the surface of the meniscus. . The amount of change in outer diameter at each point of the meniscus can be obtained. . The slope of each point of the meniscus can be calculated. . The area and volume of the meniscus can be obtained from the outer diameter and inclination of each point of the meniscus. . Outer diameter data can also be processed by statistical methods other than averaging. In this case, the effects of measurement errors and defects on the surface of the meniscus can be eliminated, and more sophisticated outer diameter measurement, tilt measurement, area measurement, and volume measurement can be performed. Is possible. . For example, it is possible to obtain the volume of the meniscus body and control the feed amount and take-up amount of the object to be measured (preform) so that it becomes constant. In this case, a reduced diameter preform with less outside diameter fluctuation is obtained. It becomes possible.

According to the outer diameter measuring apparatus of the second aspect of the present invention, the control circuit can accurately determine the measurement position at the time of multipoint measurement, so that the outer diameter can be measured at a predetermined position even when the reciprocating movement is performed, and the measurement Accuracy is improved.

[Brief description of drawings]

FIG. 1A is a perspective view showing an embodiment of an outer diameter measuring apparatus of the present invention, and FIG. 1B is an explanatory view showing an example of multipoint measurement by the measuring apparatus.

2A is a horizontal cross-sectional view of the measuring apparatus of FIG. 1, and FIG. 2B is a vertical cross-sectional view of the measuring apparatus of FIG.

3 is an explanatory view illustrating a movable mechanism of a movable mechanism in the outer diameter measuring device of FIG.

FIG. 4 is an explanatory view showing another example of the movable mechanism of the movable mechanism in the outer diameter measuring device of FIG.

5 is a block diagram of a position detection mechanism in the outer diameter measuring device of FIG.

FIG. 6 is a perspective view showing an example of a conventional outer diameter measuring device.

[Explanation of symbols]

 1 DUT 2 Light emitting part 3 Light receiving part 4 Moving mechanism 5 Position detecting mechanism 6 Control circuit

Claims (2)

[Claims] 1. A light projecting portion (2) for projecting light wider than its outer diameter toward the object to be measured (1) and a position opposite to the light projecting portion (2) with the object to be measured (1) sandwiched therebetween. To be measured (1)
And a light receiving section (3) for receiving the light not blocked by the light receiving section (3), wherein the outer diameter measuring apparatus is configured to obtain the outer diameter of the DUT (1) from the light received by the light receiving section (3). A movable mechanism (reciprocatingly movable in the device, the light projecting portion (2) and the light receiving portion (3) for measuring the outer diameter of the meniscus portion of the DUT (1) along the longitudinal direction of the DUT (1). 4) and a position detecting mechanism (5) for detecting the positions of the reciprocating light projecting part (2) and the light receiving part (3), the outer diameter measuring device. 2. The outer diameter measuring apparatus according to claim 1, wherein the moving positions of the reciprocating light projecting section (2) and light receiving section (3) are detected, and the object to be measured (1) in the moving direction. An outer diameter measuring device, comprising a control circuit (6) capable of measuring the outer diameter at two or more positions of the meniscus portion.