JPH1114320A - Dimension measuring device - Google Patents

Abstract

(57) [Problem] To enable a plurality of optical measuring means to be installed close to each other and to accurately measure the shape and dimensions of a cross section of the wire rod that is close to the same cross section. SOLUTION: An optical measuring unit M1 irradiates a plane light L1 to the wire W so as to cross the wire W and captures a shadow image of the wire W by a CCD image sensor 36. Two optical measuring means M1 are arranged around the wire W at an angle of 90 degrees, and these optical measuring means are shifted by the thickness d of the plane lights L1 and L2, and the plane light of each optical measuring means is shifted. L
1 and L2 do not overlap each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimension measuring apparatus for measuring a sectional shape and an outer diameter by irradiating an object such as a wire with light and capturing an image of the image.

[0002]

2. Description of the Related Art In order to measure the cross-sectional shape of a rolled wire rod on-line, for example, Japanese Patent Application Laid-Open No. 7-35517 discloses the following optical dimension measuring apparatus. This involves passing a wire through the center of the disk, providing a condensing lens for converting divergent light from a light emitting source into parallel light on one radial side of the plate surface of the disk, and providing the other radial side Further, an image forming lens for forming an image on a light receiving element of parallel light including a shadow when the light passes through the wire is provided. According to this measurement device,
While changing the irradiation angle of the parallel light to the wire by rotating the disk, the diameter of the wire at each irradiation angle is known from the width of the image on the light receiving element, and this is performed for the entire circumference of the wire, so that the cross-sectional shape is obtained. Can be measured.

In order to measure the cross-sectional shape of a wire passing at high speed while keeping the rotation speed of a disk within an appropriate range, Japanese Patent Application No. 8-82445 discloses a light emitting source, a condenser lens, It has been proposed to provide a plurality of optical measuring means composed of a lens and a light receiving element on a disk at different angles. For example, as shown in FIG. 4, if the two optical measuring means M1 'and M2' are provided at different angles by 90 degrees, the sectional shape can be doubled at twice the speed even if the rotation speed of the disk is the same. Can be measured. In FIG. 4, reference numeral 31 denotes a light emitting diode serving as a light emitting source, 32 denotes a condenser lens, 35 denotes an image forming lens, 36 denotes a CCD image sensor as a light receiving element, and a black area denotes a shadow generated by the wire W.

[0004]

In the case where a plurality of optical measuring means M1 'and M2' are provided as described above, it is preferable that the optical measuring means M1 'and M2' be as close as possible in the longitudinal direction of the wire W in a section close to the same section. Outer diameter can be obtained. However, when the conventional optical measuring means are brought closer to each other, the parallel light of the optical measuring means M1 'is reflected on the surface of the wire W and enters the CCD image sensor 36 of the optical measuring means M2, as shown by the arrow in FIG. However, an error may occur in the outer diameter measurement. This will be described with reference to FIG.

FIG. 5 shows the change over time of the output signal of the CCD image sensor. In FIG. 5A, the area D where the signal level decreases in one scan corresponds to the image of the wire W and its width. Sw is proportional to the outer diameter of the wire W. However, when the reflected light from the other optical measuring means enters, as shown in FIG.
Within, the signal level becomes high like noise due to the reflected light.
In particular, if such an increase in the signal level occurs at both ends of the region D, the region width Sw fluctuates, so that accurate measurement of the wire diameter cannot be performed. This problem is particularly serious in the case of a wire having a high reflectance such as a stainless steel wire.

Therefore, the present invention solves such a problem, and enables a plurality of optical measuring means to be installed close to each other so that the shape of a cross section close to the same cross section of an object can be accurately measured. It is an object of the present invention to provide a dimension measuring device.

[0007]

In order to achieve the above object, according to the present invention, plane light (L1, L2) is applied to an object (W).
The optical measuring means (M) which irradiates the light beam across the object and captures an image of the object (W) by the light receiving element (36).
1, M2) are arranged around the object (W) at different angles, and these optical measuring means (M1, M2) are shifted by the thickness (d) of the plane light (L1, L2). And the plane light (L1, L2) of each optical measuring means (M1, M2).
L2) do not overlap each other.

In the present invention, since the object is irradiated with plane light and the optical measuring means is shifted by the thickness of the plane light, the plane light of one optical measuring means is applied to the object. The reflected light generated by the reflection does not mix with the plane light of the other optical measuring means, and the cross-sectional shape of the object can be accurately measured. Since the positions of the optical measuring means can be made closer to each other as compared with a conventional apparatus using parallel light having a circular cross section, the shape of a cross section of the object close to the same cross section can be measured.

The plane light is generated by, for example, passing parallel light having a circular cross section through a slit. Further, if a slit having a shape equal to the cross-sectional shape of the plane light is provided in front of the light receiving element, even if the reflected light is scattered on the surface of the target object, it is possible to reliably prevent the reflected light from being mixed.

[0010]

FIG. 1 is an overall vertical sectional view of a dimension measuring apparatus. In the drawing, a thick-walled cylindrical holding portion 11 is provided on a fixed base 1 in a horizontal posture, and a rotating cylinder 2 is disposed in the holding portion 11, and a bearing 21 provided at two positions in an axial direction is provided. Supported. A pulley 22 is fitted around one end of the rotary cylinder 2, and a belt 23 extending from a drive motor (not shown) is suspended on the pulley 22 to rotate the rotary cylinder 2 at a constant speed. The rolled wire W as an object passes through the center of the rotary cylinder 2 in the horizontal direction.

At one end of the rotary cylinder 2, there is formed a large-diameter disk portion 24 which is covered by a cover 241 and has a wire W penetrating the center thereof. Optical measuring means M1 and M2 so as to intersect at different degrees
2 are provided. Each of the optical measuring means M1 and M2 is provided with a light emitting diode 31 as a light emitting source on one radial side of the plate surface of the disk portion 24 with respect to the wire W passing through the center of the disk portion 24. A condensing lens 32 for converting the emitted divergent light into parallel light having a circular cross section, and a slit member 33 for converting the parallel light into plane light L1 and L2 having a constant thickness as described later, and on the other radial side Is a slit member 3 that allows only plane light L1 and L2 including a shadow (black area in the figure) generated when the wire W is crossed to pass through
4, an imaging lens 35 on which the plane lights L1 and L2 are incident,
The imaging lens 35 has a CCD image sensor 36 as a light receiving element that forms a shadow image on a light receiving surface. The plane lights L1 and L2 pass through the transparent glass window 37 before and after the wire W.

In FIG. 1, a large-diameter gear 12 is fixed to one end of the holding portion 11 facing the disk portion 24, and a small-diameter gear 13 meshes with the outer periphery of the gear 12 (FIG. 2). ). The gear 13 is a generator 38 provided on the plate surface of the disk portion 24.
When the rotating cylinder 2, that is, the disk portion 24 rotates, the gear 13 moves while rotating around the outer periphery of the gear 12, thereby generating power.
The generated power is supplied to the light emitting diodes 31 of the optical measuring means M1 and M2.

A ring plate 25 is provided on the outer periphery of the intermediate portion of the rotary cylinder 2.
Are fitted, and these ring plates 25
1 are respectively located in ring-shaped concave grooves 14 formed on the inner peripheral surface. Coils are printed on the plate surface of the ring plate 25 and the groove surface of the concave groove 14 opposed to the ring plate 25 to form a rotary transformer (not shown). The output signal is taken out to the fixed base 1 side without contact. Except for the portion where the glass window 37 is provided, heat insulating tubes 41 and 42 are provided around the wire W.

FIG. 3 is a perspective view of the optical measuring means M1. In the figure, divergent light emitted from a light emitting diode 31 is converted into parallel light having a circular cross section by a condenser lens 32 and enters a slit member 33. Slit member 33
Has a rectangular slit 331 having a constant width (for example, 10 mm).
Is formed, and the parallel light passes through the slit 331 to become a plane light L1 having the same cross section as the slit 331 and a constant thickness d. The plane light L1 traverses the wire W on the way, and enters the slit member 34 including the shadow (black area in the figure) of the wire W generated at this time. Slit member 34
Is formed with a slit 341 having the same shape as the slit member 33. After passing through the slit 341, the plane light L1 is made incident on the light receiving surface of the CCD image sensor 36 by the imaging lens 35. On the other hand, also in the optical measuring means M2, a plane light L2 having a constant thickness d is formed in the same configuration, and the plane light L2 is transmitted through the wire W at the plane of the optical measuring means M1 as shown in FIG. In the present embodiment, the wires W intersect with the light L1 and are shifted in the longitudinal direction of the wires W so as not to overlap with each other. At this time, since each of the plane lights L1 and L2 has a rectangular cross section having a constant thickness d as described above, the plane lights L1 and L2 do not overlap each other by shifting the position by the thickness, and the plane lights L1 and L2 do not overlap each other. Light reflected by the wire W of L2 is prevented from being mixed into the plane light L1.

Therefore, in the present embodiment, the positions of the two optical measuring means M1 and M2 are adjusted in the longitudinal direction of the wire W by the plane light L.
By slightly shifting the thickness by 1, d2, the reflection light from other optical measuring means can be prevented from being mixed with each other, and the wire diameter can be reliably measured. As described above, compared with the case of using parallel light having a circular cross section as in the related art, the present embodiment uses plane light of a constant thickness, so that the two optical measuring means M1 and M2 are located close to each other. The wire diameter measured by these optical measuring means M1 and M2 is the wire W
Of the wire W can be grasped more accurately.

In the above embodiment, the surface of the wire is usually formed at various angles due to sink marks during rolling, and the reflected light may be scattered. Therefore, it is preferable to provide the slit member 34 in order to reliably prevent the reflected light from entering from other optical measuring means. It is more effective to provide the slit member 34 as close to the wire W as possible.

In order to generate the plane lights L1 and L2, it is not always necessary to adopt the configuration as in the above embodiment. For example, a large number of light emitting diodes are arranged in a straight line, and the divergent light emitted from these light emitting diodes is cylindrical. A configuration in which a lens converts the light into planar light having a constant thickness may be used.

In the above embodiment, two optical measuring means are provided, but three or more optical measuring means may be provided. Also, the optical measuring means does not necessarily need to be provided on a rotating disk,
It may be fixed at an angle around the wire. Further, the object is not limited to a wire.

[0019]

As described above, according to the dimension measuring apparatus of the present invention, a plurality of optical measuring means can be set close to each other by using plane light for measurement.
It is possible to accurately measure the outer diameter or shape of a cross section close to the same cross section of the object.

[Brief description of the drawings]

FIG. 1 is an overall vertical sectional view of a dimension measuring device, showing an embodiment of the present invention.

FIG. 2 is a front view of a rotating cylinder disk portion.

FIG. 3 is a perspective view of an optical measuring unit.

FIG. 4 is a schematic configuration diagram of a conventional optical measuring means.

FIG. 5 is an output signal waveform diagram of the CCD image sensor.

[Explanation of symbols]

31: light emitting diode, 32: condenser lens, 33, 34
... Slit member, 35 ... Imaging lens, L1, L2 ... Plane light, M1, M2 ... Optical measuring means, W ... Wire (object).

Claims (1)

[Claims] 1. A plurality of optical measuring means for irradiating plane light to an object so as to traverse the object and capturing an image of the object by a light receiving element are arranged around the object at different angles, The optical measuring means is shifted by the thickness of the plane light so that the plane lights of the optical measuring means do not overlap each other.