JPH0236302A - Dimension measuring method for flat cable - Google Patents

Abstract

PURPOSE:To measure the dimensions of respective parts by using signals outputted by a receiving coil and an edge sensor when the flat cable moves across an uneven AC magnetic field. CONSTITUTION:The sensor 1 has magnetic heads 3 and 4, and the magnetic head 3 is arranged opposite an exciting coil 7 and the receiving coil 8 and mounts shield plates 14 and 15 with slits, thereby producing an uneven AC magnetic field. A magnetic head 4 also produces an uneven AC magnetic field. here, when the flat cable where many metallic wires are juxtaposed while insulated crosses the uneven AC magnetic field, the variation of electromotive forces induced across the receiving coils 8 and 13 becomes maximum when each metallic wire passes a slit position. Then a signal processing circuit 20 inputs the output signals of the coils 8 and 13 to measure pitches between adjacent metallic wires and the overall pitch. Further, an edge sensor 19 detects both ends of the cable with laser light and the circuit 20 measures the overall width of the cable with the output signal of the sensor 19 and the margin of the cable with the signals of the sensor 19 and coils 8 and 13.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a flat cable dimension measurement method for measuring the dimensions of each part of a flat cable formed by arranging a plurality of metal wires in parallel within a flat strip-shaped insulator. Regarding.

(Prior art) With the spread of electronic equipment such as OA equipment, flat cables, that is, metal wires (hereinafter referred to as core wire conductors), are arranged in parallel at small intervals and integrally insulated with an insulating material to form a strip. As the demand for cables formed in flat cables increases, there is a strong demand for automating the process of connecting each terminal of a large number of parallel core conductors of the flat cable to a connector. In order to automate the connection of such a large number of parallel conductors and connectors, it is necessary to determine the total width of the flat cable, the margin, i.e. the distance from the side end surface of the flat cable to the center of the outermost conductor, and the distance between each parallel conductor. It is necessary that the dimensions of each part, such as the distance between the centers of the core wire conductor, the pitch, and the total pitch, are accurately set to specified values. Therefore, it is necessary to measure the dimensions of each of these parts with high precision, and this is usually done visually.

(Problem to be solved by the invention) However, it is extremely difficult to accurately measure each dimension such as the center distance (hereinafter referred to as pitch) and margin of a large number of core conductors arranged at small intervals by visual inspection. As a method of electrically detecting the pitch of parallel core wire conductors, which is a difficult work and has low work efficiency,
A magnetic head is formed by arranging an excitation coil and a receiving coil to face each other, the excitation coil is excited by an alternating current, the parallel core wire conductor is moved within the gap, and when the core wire conductor crosses the magnetic field, the receiving coil Some devices detect pinches in the core conductor by detecting changes in the electromotive force induced in the wire.

In order to increase the detection sensitivity of magnetism and to reduce the influence of other conductors adjacent to each other at a small distance, it is necessary to converge the 6f flux onto a thin core conductor, and by winding the coil. It is necessary to process the tip of the ferrite core used as the magnetic material to be extremely thin (diameter Q, 5 mm or less). However, since the ferrite core is a brittle and hard material, it is extremely difficult to process it.

In addition, with the above detection method, it is possible to detect the pitch between each core conductor arranged in parallel, but it is not possible to measure other dimensions such as the total width, margin, and total pinch of the flat cable. There are problems such as not having one.

The present invention has been made in view of the above-mentioned points, and includes: 7) Dimension measurement of flat cables that can measure the dimensions of each part such as the total width, margin, pinch of each core conductor, and total pitch of the cable. The purpose is to provide a method.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, a shielding plate having slits is attached to each coil of a magnetic head in which an excitation coil and a receiving coil are disposed facing each other. An alternating current magnetic field is formed, and in the nonuniform alternating current magnetic field, a large number of metal wires are moved across a flat cable in which insulation is arranged side by side to detect changes in the output signal of the receiving coil. The end of the flat cable is detected, and the dimensions of the flat cable are measured based on the output signals of these receiving coils and edge sensors.

(Function) When a flat cable is made to cross within the gap of the non-uniform AC magnetic field of the magnetic head, the change in the electromotive force induced in the receiving coil becomes maximum when each metal wire passes through the slint position of the shielding plate. Then, the output signal of this receiving coil is taken into a signal processing circuit, and the pitch of each adjacent metal wire and the total pitch are measured. On the other hand, edge sensors detect both ends of the flat cable and output signals. The output signal of this edge sensor is taken into the signal processing circuit, and the total width of the flat cable is measured using the signal from the edge sensor, and the margin of the flat cable is measured using the signal from the edge sensor and the receiving coil. This allows each dimension of the flat cable to be measured.

(Example) An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an outline of a sensor for detecting a core conductor for carrying out the flat cable dimension measurement method according to the present invention. The magnetic head 3 has a substantially U-shaped core 5 with a rectangular cross section, and a cylindrical magnetic pole 6.6 is integrally formed on the inner surface of the open end of the core 5.
The end faces of these magnetic poles 6.6 are arranged opposite to each other with a slight gap G between them. An excitation coil 7 and a reception coil 8 (FIG. 3) are wound around the tip of each magnetic pole 6.6, respectively. The other magnetic head 4 is also formed similarly to the magnetic head 3, and an excitation coil 12 and a receiving coil 13 (FIG. 5) are wound around the tip of each magnetic pole 1111 at the tip of the core 10.

Shield plates 14.15 are attached to the excitation coil 7 and reception coil 8 of the magnetic head 3, and shield plates 16.17 are attached to the excitation coil 12 and reception coil 13 of the magnetic head 4. As shown in FIG. 2(a), the shielding plate 14 is made by dividing a bottomed cylindrical body into two parts 14a and 14b in the axial direction, and fixing these two parts with adhesive to form a bottomed cylindrical shape again. Bottom 1
Slit 14d at diameter position 4c (Fig. 1, Fig. 7)
was formed. Therefore, the width d of the slit 14d is set to be as narrow as the thickness of the adhesive film. The shielding plate 15 is also formed in the same manner as the shielding plate 14, as shown in FIG. 2(b). The shielding plates 16 and 17 of the excitation coil 12 and the receiving coil 13 of the magnetic head 4 are also formed in exactly the same manner as the shielding plates 14 and 15. These shielding plates 14 to 17 are formed of thin plates of copper having good conductivity, for example.

As shown in FIGS. 1 and 3, the shielding plates 14.15 are fitted onto the excitation coil 7 and the receiving coil 8 at the tip of each magnetic pole 6.6, and these shielding plates 14.15 The slits 14d and 15d are located in the same vertical plane, facing each other, and are arranged along the width direction of the side portion 5a of the core 5. The shielding plates 16.17 are fitted over the excitation coil 12 and the receiving coil 13 at the tip of each magnetic pole 11.11, respectively, and the slits 16d and 17d are located in the same vertical plane facing each other, and the core 10 It is arranged along the longitudinal direction of the side part 10a. That is, slits 14d and 15d of shielding plate 14.15 and slit 1 of shielding plate 16.17.
6d and +7d are arranged substantially at right angles to each other.

The magnetic heads 3 and 4 are arranged side by side with a slight interval as shown in FIG. 1, housed in a casing 2 shown by a two-dot chain line in FIG. 3, and integrally molded with a filler material (not shown). be done.

Each excitation coil 7.12 of these magnetic heads 3.4 is
As shown in FIG. 5, the signal processing circuits 20 are connected in series.
The high-frequency excitation power supply circuit 21 is connected to the same high-frequency excitation current, that is, the excitation current with the same voltage and phase is supplied. Further, each receiving coil 8.13 is differentially coupled and connected to the differential amplifier circuit 22.

An example of the casing 2 of the sensor 1 is provided with edge sensors 19 for detecting both ends of the flat cable 44, as shown in FIGS. 3 and 4. This edge sensor 19 is constituted by, for example, a laser switch, and the light projection window 19b of the laser light projection section 19a is arranged on a line connecting the centers of the shielding plates 14.16 of the magnetic head 3.4 of the sensor 1. The upper surface 40c is irradiated with laser light, the reflected laser light L' is received by the light receiving part 19c, and both ends 40a, 40 of the flat cable 40 are connected.
b. When the light receiving section 19'c receives the reflected laser beam L', it outputs an edge signal and outputs an edge signal to the analog-to-digital converter (
(hereinafter referred to as an A/D converter) 26.

The flat cable (tape card wire) 40 has a large number of core conductors 4, for example, 8 pieces, as shown in FIGS. 4 and 6.
1 to 48 are arranged in parallel at slight intervals, and the insulating member 4
9 and is integrally molded into a band shape. This flat cable 40 has a total width of W, a pitch between each core conductor 41 to 48 of P, ~P7, and a total pitch of P.
, the margins on both sides are set to Ma and Mb.

The action will be explained below.

A high frequency excitation TLM circuit 2 is connected to the excitation coil 7 of the magnetic head 3.
When a high-frequency excitation current is supplied from the excitation coil 7, the high-frequency magnetic flux generated from the excitation coil 7 interlinks with the bottom surface (end surface) 14C of the shielding plate 14, as shown by the dotted line in FIG. 7(a). eddy currents are induced. This high-frequency magnetic flux also interlinks with the bottom surface (end surface) 15C of the shielding plate 15 on the side of the other opposing magnetic pole 6, and the end surface 15C is shown in FIG. 7(b).
Eddy currents are induced as shown by the dotted lines.

The eddy current induced in the shielding plate 14.15 is caused by the excitation coil 7.
Therefore, the magnetic flux passing through each bottom surface 14c and 15c of the shielding plate 14.15 is weakened and has a low magnetic flux density. On the other hand, these bottom surfaces 14
No eddy current is generated in the portions of 14d and 15d, and therefore each of these 14d and 15c
The magnetic flux passing through 4d and 15d is unhindered and has a high magnetic flux density. As a result, the gap G between the shielding plates 14 and 15
The magnetic flux distribution in the pickpocket 7) 14 is as shown in Figure 8.
This results in a non-uniform magnetic flux distribution concentrated in the vertical plane at the position d, 15d.

In FIG. 8, the horizontal axis represents the slit 14d of the shielding plate 14.
The vertical axis represents the distance X from the center of the magnetic flux density Bm.

As a result, the magnetic flux distribution in the gap G between the shielding plates 14 and 15 becomes extremely narrow and has a high magnetic flux density at the positions of the slits 14d and 15d.

The magnetic flux distribution similar to that of the magnetic head 3 can be obtained for the other magnetic head 4 as well. Note that the directions of the gradients of the magnetic flux distributions of the magnetic heads 3 and 4 are substantially perpendicular to each other.

A flat cable 40 is inserted into the gear G of each magnetic rod 3.4 of this sensor 1 as shown in FIG. 3, and the flat cable 40 is moved by moving the sensor 1 at a constant speed as shown by arrow A. Let it cross. At this time, the shielding plate 14 of the magnetic head 3 and the slits 14d and 15d of the wire 5 cross parallel to the core conductors 41 to 4 (see FIG. 9(a)).
), slit 16d of shielding plate 16.17 of magnetic hand 4
, 17d cross the core conductor 31 at right angles (FIG. 9(b)).

When the magnetic pole 6.6 of the magnetic head 3 crosses the core conductor 31,
An eddy current is induced in the core wire conductor 31, and the eddy current becomes maximum at the position passing through the slits 14d and 15d, where the magnetic flux density is maximum, and becomes smaller as the slits 14d and 15d move away from each other. Therefore, the magnetic flux interlinking with the receiving coil 8 of the magnetic hand 3 is transmitted through the core conductor 41.
~48, and changes greatly at the positions of the slits 14d and 15d. That is, the magnetic flux interlinking with the receiving coil 8 is transmitted through the core conductor 4 through the slits 14d and 15d of the shielding plate.
The amount of change is maximum when it is located directly above (center) on days 1 to 4. As a result, the induced electromotive force of the receiving coil 8 is
The slits 14d and 15d of the shielding plate are the core conductors 41-48.
It is minimum when it crosses .

Each slit 14d of the shielding plate 14.15 of the magnetic head 3,
15d crosses in parallel to the core conductors 41 to 48, the electromotive force induced in the receiving coil 8 is as shown in FIG.
). That is, the electromotive force of the receiving coil 8 becomes the minimum at the moment when the slits 14d and 15d cross the center of each core conductor 41-4, and the amount of change is large and steep. .

Each slit 16d of the shielding plate 16.17 of the magnetic helad 4,
17d crosses the core conductors 41-4 at right angles, the electromotive force induced in the receiving coil 13 is as shown in FIG.
It changes as shown in b). That is, the electromotive force of the receiving coil 13 is caused by the slits 16d and 17d forming the respective core conductors 41 to 4.
It remains approximately constant across 8, and the amount of change is small and gradual.

These receiving coils 8 and 13 are differentially coupled,
Therefore, each output voltage cancels each other out, and as a result, the instability of the amplitude and frequency of the excitation current, the drift of the output signal due to the influence of the surrounding electromagnetic field, and the level of noise are greatly suppressed. Only the signal at the center position of 48 is detected to be large. Therefore, sensor 1 should be placed at arrow A in FIG.
By moving in the direction, it becomes possible to accurately detect each center position of each core conductor 41 to 48 of the flat cable 40.

Further, the edge sensor 19 shown in FIG. 3 constantly emits laser light, and when there is no obstacle, it is not reflected, and therefore the light receiving section 19c does not output an edge signal. When the sensor l moves in the direction of arrow A and is reflected by one end of the upper surface 40c of the flat cable 40, it receives the reflected laser beam L° and outputs an edge signal. As a result, the edge sensor 19 detects the one end surface 40a of the flat cable 40. Then, the edge sensor 1
9 is attached to the top surface 4 while moving on the flat cable 40.
It receives the reflected laser beam L' reflected by 0c and continues to output an edge signal.

When the projected laser beam reaches the other end of the upper surface 40c of the flat cable 40, the edge sensor 19 becomes unable to receive the reflected laser beam L°, and the edge signal becomes 0. Thereby, the edge sensor 19 detects the other end surface 40b of the flat cable 40.

The signal processing circuit 20 (FIG. 5) amplifies the differential signal of the receiving coil 8.13 using a differential amplifier circuit 22, inputs it to a low frequency amplifier circuit 25 through a detection circuit 23 and a rectifier circuit 24, and outputs the differential signal from the receiving coil 8. After being amplified by the frequency amplification circuit 25, the A/D
The converter 26 converts it into a corresponding digital signal and inputs it to the microcomputer 27. In addition, edge sensor 19
The edge signal outputted from the microcomputer 27 is also input to the microcomputer 27 after being converted into a corresponding digital signal by the A/D converter 26 .

The microcomputer 27 receives m end faces 40a of the flat cable 40 inputted from the edge sensor 19.
The margin Ma (FIG. 6) on one side of the flat cable 40 is measured using the detection signal indicating the center position of the first core conductor 41 inputted from the sensor 1. Next, the pitch P1 between each of the core conductors 41 to 48 is determined by a detection signal indicating the center position of each of the core conductors 42, 43, . ~P, is measured. Furthermore, these pitches P1 to P7 are totaled to give the total pitch P(=PI +p2+・
...+P,) is set.

Then, the margin Mb on the other side of the flat cable 40 is measured based on the detection signal indicating the center position of the last core wire conductor 48 and the detection signal of the other end surface 40b of the flat cable 40 inputted from the edge sensor 19. Furthermore, the total width W of the flat cable 40 is measured based on the detection signal of the first end face 40a of the flat cable 19 inputted from the sensor 19 and the detection signal of the other end face 40b inputted last. .

Then, as shown in FIG. 4, the sensors 1 are scanned alternately in the directions of arrows A and A'' with respect to the flat cable 40 being conveyed in the direction shown by arrow B, and the above-mentioned values of the flat cable 40 are continuously measured. Then, the signal processing circuit 2
The respective values of the flat cable 40 measured by 0 are printed out by an output device 30 such as a printer.

In this embodiment, two magnetic heads 3 and 4 are used as the sensor 1, each excitation coil is equally excited by the same high-frequency excitation power source, and each receiving coil is differentially coupled. Although the case has been described, the present invention is not limited to this, and the sensor may be configured using only the magnetic head with higher detection sensitivity, that is, the magnetic head 3. Of course, when two magnetic heads are used as in the embodiment, one
Compared to sensors using multiple magnetic heads, it is possible to significantly suppress output signal drift and noise levels caused by instability of the excitation current amplitude and frequency, the influence of surrounding electromagnetic fields, etc. The detection sensitivity can be greatly increased.

Further, in this embodiment, a case has been described in which a laser inch is used as an edge sensor, but it goes without saying that the invention is not limited to this, and other sensors may be used.

(Effects of the Invention) As explained above, according to the present invention, each coil of a 6ft air head in which an excitation coil and a reception coil are arranged facing each other,
A shield plate with slits is attached to form a non-uniform alternating current magnetic field, and a large number of metal wires are moved across a flat cable in which insulation is arranged in parallel within the non-uniform alternating magnetic field to detect changes in the output signal of the receiving coil. At the same time, edge sensors detect both ends of the flat cable, and the dimensions of the plant cable are measured using the output signals of these receiving coils and edge sensors. , it becomes possible to measure each dimension such as the total pitch and the total width of the flat cable accurately, quickly, and continuously, and it has excellent effects such as being able to improve work efficiency.

[Brief explanation of the drawing]

FIG. 1 is an i↓ perspective view showing an embodiment of the magnetic head of a sensor applied to the method for measuring the distance between metal wires according to the present invention, FIG. 2 is an assembled perspective view of the shielding plate shown in FIG. 1, and FIG. The figure is a cross-sectional view of the magnetic head in Figure 1, Figure 4 shows the main parts of the sensor in Figure 3 and the relationship with the flat cable, and Figure 5 is a signal processing circuit applied to the measurement method according to the present invention. A circuit diagram showing an example of the 6th circuit is the arrow V+- of the flat cable in FIG. 4.
7 is a cross-sectional view along V+, FIG. 7 is a diagram showing the eddy current induced on the bottom surface opposite to the shield of the magnetic head in FIG. 1, and FIG.
Figure 9 is a diagram showing the relationship between the magnetic head in Figure 4 and the core conductor, and Figure 10 is a diagram showing the magnetic flux distribution in the gap between the shield plates of the magnetic head in Figure 4. It is a figure showing the electromotive force of a receiving coil. 1...Sensor, 2...Casing, 3.4...Magnetic head, 5.10...Core, 6.11...Magnetic pole,
7.12... Excitation coil, 8.13... Receiving coil, 14-17... Shielding plate, 14d-17d... Slit, 19... Edge sensor, 20... Signal processing circuit, 40 ...Flat cable, 41-48... Core conductor (metal wire), 49... Insulating member.

Claims (2)

[Claims] (1) A shield plate with slits is attached to each coil of a magnetic head in which an excitation coil and a receiving coil are arranged facing each other to form a non-uniform AC magnetic field, and a large number of metal wires insulate the non-uniform magnetic field. A change in the output signal of the receiving coil is detected by moving the parallel flat cables across, and an edge sensor detects both ends of the flat cable, and the output signals of the receiving coil and edge sensor are used to detect the change in the output signal of the receiving coil. A method for measuring the dimensions of a flat cable, the method comprising measuring the dimensions of a flat cable. (2) Dimension measurement of the flat cable according to claim 1, characterized in that the dimensions of the flat cable are a margin, a pitch between a large number of insulated metal wires arranged in parallel, a total pitch, and a total width of the cable. Method.