JP3420563B2 - Eccentricity measuring device for insulated wire - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated electric wire in which a conductor core wire is covered with an outer cover of an insulating material such as various electric wires and cables, and the conductor core is located at the center of the outer cover, which is the center of the whole covered electric wire. The present invention relates to a technique for measuring eccentricity, which is a displacement of the position of the center of a line.

[0002]

2. Description of the Related Art In the production of a coated electric wire in which a conductor core wire is covered with an insulator outer cover (hereinafter referred to as an insulation outer cover) like various electric wires and cables, the conductor core wire is correctly positioned at the center of the whole covered electric wire. Is important. If the conductor core wire is not correctly located in the center of the whole covered wire, that is, the position of the center of the conductor core wire (hereinafter, center of the core wire) and the position of the center of the insulating outer cover (hereinafter, center of the outer cover) are aligned. If not eccentric,
Since a part of the insulating cover having a small thickness appears, a problem arises in terms of reliability and the like. Therefore, in the product inspection, it is checked whether or not the center of the core wire and the center of the outer skin coincide with each other with high accuracy. Therefore, an eccentricity measuring device for measuring the degree of eccentricity between the conductor core wire and the insulating jacket is required.

[0003]

Among the constitutions of the eccentricity measuring device, an optical method can be used for measuring the center of the outer skin.
That is, parallel light is emitted with a width larger than the outer diameter of the covered electric wire, and the outer diameter of the covered electric wire is measured from the width of light shielded by the covered electric wire. Then, it is possible to obtain the center of the outer skin by performing such outer diameter measurement in two orthogonal directions.

An electromagnetic method can be used to measure the center of the core wire. That is, an alternating current is applied to the conductor core wire to generate an alternating magnetic field around the conductor core wire. A plurality of coils are provided around the conductor core wire so as to interlink with the magnetic flux of the alternating magnetic field, and the center position of the conductor core wire is measured from the balance of the induced currents flowing through the coils. Specifically, each coil is arranged at a position equidistant from a predetermined mechanical center position (measurement origin). If the conductor core is coincident with the measurement origin, the induced currents flowing through the coils are equal, but if there is eccentricity, they are not equal. Therefore, the output signal based on the induced current flowing in each coil is arithmetically processed to obtain the deviation of the conductor core wire from the measurement origin. Then, the eccentricity is obtained by comparing with the measured position of the center of the outer skin.

Among the constructions of such an eccentricity measuring instrument, the measurement of the outer skin center by an optical method has a simple measuring principle, little influence of disturbance, and relatively stable measuring conditions. , Reliable ones can be easily obtained. However, measurement of the cord center by electromagnetic techniques, the distribution of the magnetic field, since the required work to obtain the center of the conductor through which current is caused to the magnetic field, the original
Even if the measurement can be performed reasonably, it is easy to cause a measurement error due to a slight variation of the measuring device, and it is difficult to perform the measurement with sufficiently high accuracy.

As a method for solving such a problem, the coils are moved integrally so that the induced currents flowing through the coils are equalized, and the deviation from the measurement origin of the center of the core wire from the distance and direction moved at that time. The required configuration can be considered. However, in order to move the coils integrally so that the induced currents flowing through the coils are equal, an expensive servo mechanism including a high-precision servo motor and the like is required, which has a disadvantage of increasing the cost of the device.

The invention of the present application has been made in order to solve such a problem, and provides a technique for providing an eccentricity measuring device for a covered electric wire which can be manufactured at a low cost in spite of facilitating highly accurate measurement. Has a significant meaning.

In order to solve the above problems, the invention according to claim 1 of the present application is a covered electric wire in which a conductor core wire is covered with an outer cover of an insulating material. An eccentricity measuring device for a covered electric wire, which measures the deviation of the position of the center of the conductor core with respect to the position of the center of the conductor as an eccentricity, and which measures the center of the outer cover optically and the outer core center measuring device. A core center measuring instrument that measures the center of the conductor core from the intensity distribution of the magnetic field in the measurement plane, which is a plane perpendicular to the length direction of the covered electric wire in the magnetic field generated by passing a high-frequency current, and an outer center measuring instrument And the output from the core wire center measuring device is provided with an arithmetic processing unit for obtaining the eccentricity, and the core wire center measuring device,
It has multiple magnetic sensors to detect the strength of
In addition, each magnetic sensor is on the measurement surface with the measurement origin as the reference.
It is placed at a known position, and the arithmetic processing unit
By comparing the magnetic field strength data output from the sensors
The position of the center of the core wire with respect to the measurement origin is calculated,
The arithmetic processing unit has a storage unit that stores correction value map information for correcting the primary data of the position of the center of the core calculated by the output from the center-of-core measuring device. Divides the measurement surface into many small areas,
This is information that sets a correction value for each area to correct the primary data when it is determined that the center of the optical fiber is located in that area from the primary data.The arithmetic processing unit outputs the output from the core center measuring device. After calculating the primary data of the position of the center of the core line, the calculation for correcting the primary data by the correction value map information is performed. Further, in order to solve the above-mentioned problems, the invention according to claim 2 has a configuration in which, in the configuration of claim 1, a laser outer diameter measuring device is used as the outer skin center measuring device. Well
In order to solve the above problems, the invention according to claim 3 is
In the structure of claim 2, the plurality of magnetic sensors are
There are four, and they are placed on a circle centered on the measurement origin.
And position it on the coordinate axis that is orthogonal to the measurement surface.
It has a structure of being. In addition, to solve the above problems
Therefore, the invention of claim 4 is the same as that of claim 1, 2 or 3.
In the configuration, four magnetic sensors are provided.
Is located on a circle centered on the measurement origin and
The configuration is such that they are located on coordinate axes that are orthogonal to each other on the measurement surface . In order to solve the above-mentioned problems, the invention according to claim 5 is the structure according to any one of claims 1, 2, 3 or 4 , wherein the correction value map information is an electric wire only having a core center without an insulating outer cover. Similarly, using a standard wire, it is obtained by measurement using an outer core center measuring device and a core center measuring device, and the measurement surface is measured according to the center position data calculated from the output from the core center measuring device. Divide into a predetermined number of areas and find the difference between the center position data calculated from the output from the outer skin center measuring device and the center position data calculated from the output from the core wire center measuring device to eliminate this difference. The information has a configuration in which a value for correction is set as a correction value for each area. In order to solve the above-mentioned problem, the invention according to claim 6 is a covered electric wire in which the conductor core wire is covered with an outer cover of an insulating material, and the conductor core wire is located at the center of the outer cover, which is the center of the whole covered electric wire. An eccentricity measuring device for coated electric wires that measures the eccentricity, which is the displacement of the center position, and an outer skin center measuring device that optically measures the center of the outer skin, and a magnetic field generated by applying a current to the conductor core wire. Of these, the core center measuring instrument that measures the center of the conductor core from the strength distribution of the magnetic field in the measurement plane, which is the plane perpendicular to the length direction of the covered electric wire, and the output from the core center measuring instrument and the core center measuring instrument. And an arithmetic processing unit that obtains an eccentricity by the output from the arithmetic processing unit, and the arithmetic processing unit obtains the coated wire by rotating the coated electric wire around its central axis without displacing it in the radial direction. Center of the core due to the output from the central measuring instrument Calculate three or more position data, calculate the center of the arc passing through the positions of the center of the core from each calculated data, and calculate the calculated center of the arc and the output from the skin center measuring instrument. Obtain the value for correcting the deviation from the center of the outer skin as the background noise correction value,
The background noise correction value is used to perform a calculation for correcting the data at the position of the center of the core.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments (hereinafter, embodiments) of the present invention will be described below. FIG. 1 is a schematic perspective view of an eccentricity measuring device according to an embodiment of the present invention. The eccentricity measuring device shown in FIG. 1 includes an outer skin center measuring device 1 for optically measuring the outer skin center, and a magnetic field generated by passing an electric current through the conductor core wire in a plane perpendicular to the length direction of the covered electric wire. A core center measuring device 2 for measuring the center of the core from the intensity distribution of the magnetic field, and an arithmetic processing unit 3 for obtaining the eccentricity from the output from the outer skin center measuring device 1 and the output from the core center measuring device 2. ing.

The eccentricity measuring device shown in FIG. 1 is used in an inspection process in a production line of the covered electric wire 4. In the inspection step, as shown in FIG. 1, the manufactured covered electric wire 4 is made to travel along a horizontal travel line. The eccentricity measuring device is designed to measure the eccentricity at a predetermined position on the traveling line (hereinafter, this position is set as a measurement origin and is indicated by O in FIG. 1).

First, the structure of the outer skin center measuring instrument 1 will be described. As the outer skin center measuring device 1, a laser outer diameter measuring device is used. That is, the outer skin center measuring device 1 includes a laser light source unit 11 for irradiating a laser beam with a width larger than the outer diameter of the covered electric wire 4 to be measured, and the laser light source unit 1.
1 and a light receiver 12 for receiving the light from 1. Two sets of the laser light source unit 11 and the light receiver 12 are provided. As shown in FIG. 1, the laser light source unit 11 and the light receiver 12 of each set are provided such that their optical axes intersect each other at a right angle. The point where the optical axes intersect is a point on the traveling line, and coincides with the measurement origin O described above.

As shown in FIG. 1, the detection signal of each light receiver 12 is sent to the arithmetic processing section 3. Figure 2
The principle of skin center measurement will be explained using. Figure 2
FIG. 2 is a diagram showing the principle of the outer skin center measuring device 1 shown in FIG. 1. In FIG. 2, the laser light from each laser light source unit 11 is parallel light parallel to the optical axis. As can be seen from FIG. 2, since the coated electric wire 4 is shaded in the laser light incident on each light receiver 12, there is a portion where the laser light is not incident due to the outer diameter of the coated electric wire 4. As the light receiver 12,
By using a photodiode array or the like arranged in the width direction of the laser beam, the position of the region of the light receiving surface where the laser beam does not enter due to the shielding can be known with high accuracy.

Since the relationship between the position at which the light receiver 12 is provided and the measurement origin O is known and does not change, from the detection signal of the light receiver 12 on one optical axis to the other optical axis. The position of the outer skin center in the direction is known, and the position of the outer skin center in the direction along the one optical axis is known from the detection signal of the light receiver 12 on the other optical axis. Then, from these data, the position of the center of the outer skin can be specified on a plane that passes through the measurement origin O and is perpendicular to the traveling line (hereinafter, measurement plane).

As shown in FIG. 1, the arithmetic processing unit 3 is a microcomputer including a processor 31 that performs arithmetic processing and a storage unit 32 that stores files used by the processor 31. The storage unit 32 includes a memory such as a RAM or a ROM or a hard disk. Storage unit 3
One of the files stored in 2 is one of the above two receivers 1.
2 is a skin center calculation program 321 for processing the data sent from 2 to obtain the skin center. Processor 3
When the data is sent from the two light receivers 1, No. 1 executes the outer skin center calculation program 321 to obtain the position of the outer skin center.

As described above, parallel light having a width larger than the outer diameter of the covered electric wire 4 is required for measuring the center of the outer cover.
In the present embodiment, the measurement accuracy is further improved by using the Fθ lens. This point will be described with reference to FIG. FIG. 3 is a diagram showing a schematic configuration of the laser light source unit 11 shown in FIGS. 1 and 2. As shown in FIG. 3, the laser light source unit 11 includes a laser light source 1
11, a rotary polygon mirror 112 that reflects the light from the laser light source 111, and an Fθ lens 113 on which the laser light from the rotary polygon mirror 112 is incident.

The laser light source 111 includes 600 to 800
A semiconductor laser having an oscillation wavelength of about nm is used. The rotary polygon mirror 112 is configured to rotate at a predetermined rotation speed by a motor (not shown). Fθ lens 11
3 is a lens designed so that light is focused at a position of F / θ on a plane perpendicular to the optical axis, where F is the focal length and θ is the angle of the light emitted from the lens with respect to the optical axis. is there. When the light receiving surface of the light receiver 12 is set to a surface on which this condensing point is scanned and the rotating polygon mirror 112 is rotated at a constant speed by a motor, the laser light is irradiated onto the light receiving surface at the same speed and at the same cycle. It is focused on and scanned. This state is
As in the case of the above description using FIG.
It is equivalent to making the light incident on No. 2, and the skin center can be measured in the same manner. The use of the Fθ lens 113 has the advantage that there is no influence of the field curvature aberration and that highly accurate measurement can be performed easily.

Next, the structure of the core center measuring device 2 will be described. As shown in FIG. 1, the core center measuring device 2 includes a current generator 21 for supplying a current to the traveling covered electric wire 4,
The current generator 21 is composed of a plurality of magnetic sensors 22 for measuring the intensity distribution of the magnetic field induced by the current generated in the covered electric wire 4.

FIG. 4 is a diagram for explaining the principle of the core center measuring instrument 2. In the present embodiment, the current generator 21 is adapted to generate an alternating current, especially a high frequency current. Specifically, the current generator 21 includes a coil 211,
A high frequency power source 212 for supplying a high frequency power source to this coil
It consists of and. As shown in FIG. 4, the covered electric wire 4
Seen at high frequencies, forms a closed circuit with the ground through the capacitance. Therefore, when a magnetic field surrounding the covered electric wire is generated by the high frequency current flowing through the coil 211, the high frequency current is induced and flows in the covered electric wire 4 via the ground. Note that the capacitance in FIG. 4 is the capacitance due to the insulating jacket, but it also includes the space capacitance between the ground and the covered electric wire 4. Moreover, the frequency of the high frequency is 100 kHz to 200 k.
It is about Hz.

Further, as the magnetic sensor 22, in the present embodiment, a magnetic sensor having a coil through which an induced current flows by a magnetic field is used. That is, the magnetic sensor 22 is mainly composed of the detection coil 221 and the galvanic device 222 that converts the current flowing through the detection coil 221 into a voltage and outputs the voltage. In FIG. 4, when a high frequency current flows through the covered electric wire 4, a magnetic field B is generated so as to circulate the covered electric wire 4. The detection coil 221 of the magnetic sensor 22 uses the magnetic field B
Of the detection coil 22.
An induced current due to the magnetic field B flows through the magnetic field 1. The induced current is detected by the galvanometer 222, converted into a voltage, amplified, and sent to the arithmetic processing unit 3.

The detection coils 221 are accurately arranged so that the positional relationship from the measurement origin O is the same. That is, the axis of each of the detection coils 221 is located on the circumference of the measurement surface centered on the measurement origin O, and is also located on the coordinate axes orthogonal to each other on the measurement surface.

As is well known, when a current I flows through an infinite electric wire, the strength density B of the magnetic field at a distance of a radius r from the electric wire on a plane perpendicular to the electric wire is represented by B = μ ₀ I / 2πr . However, μ ₀ is the magnetic permeability in vacuum. As can be seen from the above equation, the induced current flowing in each detection coil 221 depends on the distance from the conductor core wire of the covered electric wire 4. Therefore, by comparing the induced currents flowing in the respective detection coils 221, the relative positional relationship of the respective detection coils 221 from the center of the core wire can be known. Since each of the detection coils 221 is known as a position with reference to the measurement origin O, the position of the center of the core wire is obtained with the measurement origin O as a reference from the magnitude of the induced current flowing in each detection coil 221.

One of the files stored in the storage unit 32 of the arithmetic processing unit 3 is a core line center calculation program 322 for calculating the core line center from the output data of each magnetic sensor 22 by the above calculation. . When data is sent from each magnetic sensor 22, the processor 31 executes this core line center calculation program 322 to obtain the position of the core line center.

Further, as shown in FIG. 1, one of the files stored in the storage unit 32 of the arithmetic processing unit 3 is a covered electric wire based on the obtained data of the position of the center of the outer skin and the position of the center of the core wire. Eccentricity calculation program 32 for calculating the eccentricity of 4
It is 3. That is, in the coordinate system centered on the measurement origin O on the measurement surface (shown by XY in FIG. 1), the difference is calculated from the coordinates of the position of the outer skin center and the coordinates of the position of the core line center. And set it as eccentricity. The calculated eccentricity is sent to the display unit 5 and displayed. Display unit 5
Displays the coordinates of the center of the outer skin, the coordinates of the center of the core wire, the eccentric distance, etc. in the XY coordinate system with the measurement origin O as the center. The coordinates are X = 10 μm, Y =
It is represented by the absolute value of the distance from the measurement origin O such as 15 μm.

The greatest feature of the apparatus of this embodiment is that the storage unit 32 of the arithmetic processing unit 3 stores a correction value map information file 324 used when measuring the center of the optical fiber. It is a point. Hereinafter, this point will be described. As described above, the measurement of the position of the conductor core wire based on the intensity distribution of the magnetic field is easily affected by the variation of the measuring equipment, and thus it is difficult to perform the measurement with sufficiently high accuracy. According to the configuration of the present embodiment, the positional accuracy of each magnetic sensor 22, the manufacturing variation of the detection coil 221 forming each magnetic sensor 22, and the like are factors that cause a measurement error.
In the present embodiment, the correction value map information is used so as to correct such a factor and perform high-precision measurement. That is, as shown in FIG. 1, the storage unit 32 of the arithmetic processing unit 3 is
A correction value map information file 324 is stored.

FIG. 5 is a diagram showing an example of data in the correction value map information file 324 shown in FIG. As described above, each magnetic sensor 22 is arranged on the measurement surface. The correction value map information shown in FIG. 5 is used to correct the primary data when the measurement surface is divided into a large number of minute areas and the center of the core is located in that area from the primary data in each area. This is information in which a correction value is set.

More specifically, an electric wire having a circular cross section and having no insulating jacket (a wire having only the center of the core wire) is used as a standard wire (hereinafter, this wire is referred to as a standard wire). Hold this standard wire with appropriate tension so that it extends horizontally, and
The Y movement mechanism is used so that it can be displaced little by little on the measurement surface. While the outer skin center measuring device 1 and the core wire center measuring device 2 are operated, the standard electric wire is gradually displaced in the XY directions on the measurement surface. Core center measuring device 2
The coordinates of the center of the core calculated by the output from the display unit 5
Is displayed, the standard electric wire is displaced so that this coordinate becomes the measurement origin O.

When it is displayed that the coordinates of the center of the core wire are the measurement origin O, it means that the wire is a standard wire without an insulating jacket.
The coordinates of the center of the outer skin measured by the outer skin center measuring device 1 should theoretically be the measurement origin O, but if there is a measurement error, it will not be the measurement origin O. Therefore, it is determined that there is eccentricity, and the eccentric distance is displayed. In this case, the coordinates of the outer skin center measuring device 1 are correct data, and the difference from this data is the measurement error included in the data of the core wire center measuring device 2. That is, although the coordinates of the center of the core center measuring device 2 are displayed as the measurement origin (0, 0), the coordinates of the center of the outer skin center measuring device 1 are (0.002,
When 0.003) is displayed, the measurement error of the core center measuring instrument 2 at that point (0,0) is (0.002,0.
003).

Next, while viewing the coordinates of the center of the core by the core center measuring device 2 on the display unit 5, the standard wire is displaced by the XY moving mechanism. Then, the display of the center of the core line on the display unit 5 is made to be, for example, coordinates (0, + d) separated from the measurement origin O by a predetermined short distance d (> 0). In this state, the display value of the coordinates of the outer skin center by the outer skin center measuring device 1 is confirmed, and the difference between the two coordinates is taken as the measurement error of the core wire center measuring device 2 at the coordinates (0, + d). Then, the standard electric wire is further displaced, and the coordinates of the center of the core by the core center measuring device 2 are, for example, (0, +2).
Then, the difference from the coordinates of the center of the outer skin by the outer skin center measuring device 1 at this time is obtained, and the difference is calculated as the coordinates (0, +2).
It is the measurement error of the core center measuring device 2 in d).

In this way, the center of the standard electric wire is positioned at each point on the measurement surface according to the displayed value of the coordinates of the center of the core by the core center measuring instrument 2, and the display by the outer skin center measuring instrument 1 at that point. The difference between the values is taken as the measurement error of the core center measuring device 2 at that point. Then, the obtained correction value for correcting the measurement error is applied to the coordinates of the point and mapped. FIG. 5 shows an example of the correction value map information thus obtained.

As shown in FIG. 5, the correction value map information is
The information is composed of the correction values applied to each area of the grid pattern in which the measurement surface is divided at regular intervals. The center of each area is the above-mentioned point where the measurement error is obtained. The width of each region is preferably as small as possible, for example, 1 mm or less, and more preferably 0.5 mm or less. Note that the correction value map information is information on the correction value in the X direction and the correction value in the Y direction at each point, but in FIG. 5, information on the correction value in the X direction is used as a map as an example.

When calculating the eccentricity, the arithmetic processing section 3 obtains the coordinates of the center of the core as described above from the output from the core center measuring device 2. Then, the correction value map information file 324 is called from the storage unit 32, it is determined which area of the correction value map information the coordinates belong to, and the data is corrected with the correction value of the area. Then, the eccentricity (distance and direction) described above is calculated from the corrected data.

Another major feature of the apparatus of this embodiment is that
The point is that the background noise included in the measurement system is corrected. The correction of the background noise is different from the correction value map information described above, and uses the twist of the covered electric wire 4. More specifically, the covered electric wire 4 may be twisted, that is, rotated around the central axis when traveling on the traveling line. This frequently occurs, for example, in the case of being wound by a reel or the like in the front.

It is assumed that the above-described eccentricity measurement is performed while the covered electric wire 4 is running while rotating about the central axis. FIG. 6 is a diagram for explaining the correction of the background noise using the twist,
It is the figure which showed the measurement result at the time of measuring the eccentricity in the state where the covered electric wire 4 was running, twisting.

When the eccentricity is obtained by measuring the center of the outer skin and the center of the core wire at different times for the traveling covered electric wire 4, as long as the covered electric wire 4 is traveling on the same traveling line (radial direction) The position of the outer skin center is always constant, unless it is displaced to. Since the outer skin center measuring device 1 has high accuracy and the error is small enough to be ignored, as shown in FIG.
The outer skin center C is always displayed in the same place.

On the other hand, when there is eccentricity, the center of the core wire is located at a position deviated from the center C of the outer cover. Therefore, when the covered electric wire 4 runs while twisting, the center of the core wire is different on an arc as shown in FIG. Is displayed in the place That is, when was the place of _{P 1} at a certain time _{T 1,} then the time _{T 2,} the _{P 2,} is displayed on the further location subsequent time _{T 3} in _{P 3.} Theoretically, P ₁ , P ₂ , and P ₃ should be located on an arc that is concentric with the outer skin center C, but as shown in FIG. 6, in reality, P ₁ , P ₂ , and P ₃ The center P ₀ of the obtained arc and the center C of the outer skin often do not coincide. This is due to the background noise included in the measurement result, which is also mainly a measurement error of the core center measuring instrument 2.

In FIG. 6, the deviation between the center P _{0 of the} circle obtained by P ₁ , P ₂ and P ₃ and the center C of the outer skin indicates the amount of background noise. Therefore, in the present embodiment, the center P of the circle obtained by P ₁ , P ₂ , and P ₃
The deviation between ₀ and the outer skin center C is obtained, the background noise correction value is determined so as to return the deviation, and the data by the above-described core wire center measuring device 2 is corrected by this background noise correction value.

As shown in FIG. 1, the storage unit 32 of the arithmetic processing unit 3 has a correction value update program 325 for updating the background noise correction value. FIG. 7 is a flowchart illustrating the correction value update program 325. When the correction value update program 325 is started, the center of the outer skin and the center of the cord are obtained three times at regular intervals, and the respective values are stored in the storage unit 32. And the storage unit 3
The data of the center of the core is read from 2 and the center of the arc where each data of the center of the core is located is obtained. Then, the background noise correction value is obtained from the obtained difference between the center of the arc and the center of the outer skin, and is updated and stored in the storage unit 32.
The calculation of the center P ₀ of the circle from P ₁ , P ₂ and P ₃ is preferably performed by the method of least squares. Also, if there are at least three points, the center of a circle passing through them can be obtained, but it is preferable to use four or more points because the accuracy becomes higher.

Next, the eccentricity calculation program 323 of the arithmetic processing unit 3 will be described below, although it will be somewhat repeated. FIG. 8 is a flowchart illustrating the eccentricity calculation program 323. As shown in FIG. 8, when the eccentricity calculation program 323 starts, it enters a state of waiting for data input from the outer skin center measuring device 1 and the core wire center measuring device 2. Then, when data is sent from the outer skin center measuring device 1, the outer skin center calculation program 321 is executed as a subprogram to calculate the outer skin center.
Next, when data is sent from the core line center measuring device 2, the core line center calculation program 322 is executed as a subprogram to calculate the core line center.

Next, the correction value map information file 324 is read out, and which area of the correction value map information is to be determined from the calculated center line center. Then, the primary data of the center of the core is corrected with the correction value registered in the area to obtain the primary correction value. Next, the background noise correction value stored in the storage unit 32 is read out, and the primary correction value is further corrected by that value to obtain a secondary correction value. Then, the eccentricity is finally calculated from the values of the center of the outer skin and the secondary correction value of the center of the cord.

In the process of executing the eccentricity calculation program 323 and repeating the eccentricity measurement, the correction value update program is executed as necessary to update the background noise correction value. For example, when the measurement environment changes due to changes in surrounding members and the like, the intensity distribution of the magnetic field may change, so the correction value update program 325 is executed.

According to the configuration of this embodiment, since the correction value map information is used in the measurement of the center of the core line where an error is likely to occur, the error is effectively corrected and the measurement can be performed with high accuracy. Further, since the laser outer diameter measuring device is used to measure the center of the outer skin, the center of the outer skin can be measured with high accuracy.
Incidentally, when the correction value map information is created, the laser outer diameter measuring device is also used to specify the center position of the standard electric wire, which is also excellent in terms of accuracy of the correction value map information. Further, in the present embodiment, since the background noise is calculated and corrected by using the twist of the covered electric wire 4, even higher measurement can be performed in this respect.

In the above embodiment, the eccentricity measurement is the measurement of the distance and direction of the eccentricity, but it may be the measurement of only the distance. Also, the distance may be obtained as an absolute value,
It may be obtained as a relative value such as a value for the entire diameter. Further, twisting of the covered electric wire 4 used for calculating the background noise often occurs naturally in the situation of the production site, but in some cases, the covered electric wire 4 is artificially twisted.
The background noise may be calculated by measuring while twisting.

[0042]

As described above, according to the invention described in claim 1 of the present application, since the correction value map information is used in the measurement of the center line of the core where an error is likely to occur, the accuracy with which the error is effectively corrected is obtained. High eccentricity measurement can be performed. Further, since it is not necessary to use an expensive servo system, the cost of the device can be reduced. According to the second aspect of the invention, in addition to the above effects, since the laser outer diameter measuring device is used for measuring the center of the outer skin, the center of the outer skin can be measured with high accuracy. Therefore, the eccentricity measurement with higher accuracy can be performed. According to the invention of claim 5 , in addition to the above effect, the laser outer diameter measuring device is also used for specifying the center position of the standard electric wire when the correction value map information is created. The accuracy of the information is high. Therefore, in this respect, the eccentricity can be measured with higher accuracy. According to the invention of claim 6, the background noise is calculated and corrected by utilizing the twist of the coated electric wire. Therefore, highly accurate eccentricity measurement can be performed at this point.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an eccentricity measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing the principle of the outer skin center measuring device 1 shown in FIG.

FIG. 3 is a laser light source unit 11 shown in FIGS. 1 and 2.
It is a figure which shows schematic structure of.

FIG. 4 is a diagram illustrating the principle of the core center measuring device 2.

5 is a diagram showing an example of data in a correction value map information file 324 shown in FIG.

FIG. 6 is a diagram for explaining correction of background noise using twist, and is a diagram conceptually showing the measurement result when the eccentricity is measured while the covered electric wire 4 is running while twisting. .

FIG. 7 is a flowchart illustrating a correction value update program 325.

FIG. 8 is a flowchart illustrating an eccentricity calculation program 323.

[Explanation of symbols]

1 Skin center measuring instrument 11 Laser light source unit 12 Light receiver 2 core center measuring instrument 21 Current generator 22 Magnetic sensor 3 arithmetic processing unit 31 processors 32 memory 321 Skin center calculation program 322 core center calculation program 323 Eccentricity measurement program 324 Correction value map information file 325 Correction value update program 4 covered electric wire 5 Display

Continuation of the front page (56) Reference JP-A-11-6709 (JP, A) JP-A-61-11606 (JP, A) JP-A-2-36303 (JP, A) Actual development Sho-Sho 21-21909 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 21/00 G01B 7/00 H01B 13/00

Claims (6)

(57) [Claims] 1. A coated electric wire in which a conductor core wire is covered with an outer cover made of an insulating material, wherein the deviation of the position of the center of the conductor core wire from the position of the center of the outer cover, which is the center of the whole covered electric wire, is measured as an eccentricity An eccentricity measuring device for electric wires, which uses an outer skin center measuring device that optically measures the center of the outer skin and a surface perpendicular to the length direction of the covered electric wire in the magnetic field generated by passing a high-frequency current through the conductor core wire. A core wire center measuring device that measures the center of the conductor core wire from the intensity distribution of the magnetic field in a certain measurement plane, and an arithmetic process for obtaining the eccentricity by the output from the outer skin center measuring device and the output from the core wire center measuring device. The core center measuring device is provided with a plurality of magnets for detecting the strength of the magnetic field.
Each magnetic sensor is equipped with
It is placed at a known position on the measurement surface with respect to the origin.
The calculation processing unit calculates the magnetic field strength output from each magnetic sensor.
By comparing the data, the position of the core center with respect to the measurement origin
The arithmetic processing unit has a storage unit that stores correction value map information for correcting the primary data of the position of the center of the core calculated by the output from the center of the core measuring device. This correction value map information divides the measurement surface into a large number of minute areas,
This is the information that sets the correction value for each area to correct the primary data when it is determined that the center of the optical fiber is located in that area from the primary data. An eccentricity measuring instrument for a covered electric wire, characterized in that after calculating the primary data of the position of the center of the core wire, the calculation is performed to correct the primary data based on the correction value map information. 2. The eccentricity measuring instrument for a covered electric wire according to claim 1, wherein a laser outer diameter measuring instrument is used as the outer skin center measuring instrument. 3. The outer skin center measuring device is a covered electrode for measuring.
Laser that emits laser light with a width larger than the outer diameter of the wire
-Receives light from the light source unit and laser light source unit
There are two sets consisting of a photoreceiver that emits light.
The optical axis of the laser light source unit and the
It is installed so that it intersects, and the point where this optical axis intersects
Is the same as the measurement origin,
Note 2 Eccentricity measuring instrument for the covered electric wire. 4. The four magnetic sensors are provided.
Is located on a circle centered on the measurement origin and
Characterized by being located on the coordinate axis orthogonal to the measurement surface
Eccentricity measurement for covered electric wire according to claim 1, 2 or 3.
vessel. 5. The correction value map information is obtained by measurement using an outer skin center measuring device and a core wire center measuring device in the same manner by using a standard electric wire which is an electric wire only having a core wire center without an insulating outer skin. That is, the measurement surface is divided into a large number of predetermined regions according to the data of the center position calculated from the output from the core center measuring instrument, and the center position data and the core line calculated from the output from the skin center measuring instrument. The information is set for each area as a correction value, which is a value for obtaining a difference from the data of the center position calculated from the output from the central measuring device and correcting so as to eliminate this difference.
The eccentricity measuring device for a covered electric wire according to 1, 2, 3 or 4 . 6. In a covered electric wire in which a conductor core wire is covered with an outer cover made of an insulating material, the eccentricity, which is the deviation of the center position of the conductor core wire from the center position of the outer cover, which is the center of the whole covered electric wire, is measured. An eccentricity measuring device for a covered electric wire, which uses an outer skin center measuring device that optically measures the center of the outer cover and a surface perpendicular to the length direction of the covered electric wire in the magnetic field generated by passing an electric current through the conductor core wire. A core center measuring device that measures the center of the conductor core wire from the intensity distribution of the magnetic field in a certain measurement plane, and an arithmetic processing unit that determines the eccentricity from the output from the outer skin center measuring device and the output from the core center measuring device. The arithmetic processing unit is arranged such that the position of the core wire center is determined by the output from the core wire center measuring device obtained by rotating the covered electric wire around its central axis without displacing it in the radial direction. Calculated three or more data of The value for correcting the deviation between the center of the calculated arc and the center of the outer skin calculated by the output from the outer skin center measuring device, as well as calculating the center of the arc passing through the positions of the center line of each core An eccentricity measuring instrument for a covered electric wire, characterized in that it is calculated as a background noise correction value, and calculation is performed to correct the data of the position of the center of the core wire with this background noise correction value.