Method for measuring shape of different diameter wire

Abstract

To provide a method for accurately measuring a shape including the length of a narrow diameter part or a taper part of a different diameter wire.SOLUTION: A plurality of noncontact external-diameter measuring instruments for measuring the external diameter of a different diameter wire at a plurality of shafts of the different diameter wire, are arranged relative to a different diameter wire having a narrow diameter part and / or a taper part in addition to thick diameter parts. The plurality of noncontact external-diameter measuring instruments are caused to move along an axial direction of the different diameter wire, from a measurement start position at one end toward a measurement ending position at the other end. With regard to the plurality of shafts, displacement of the noncontact external-diameter measuring instrument from the measurement start position along the axial direction of the different diameter wire, and an external diameter of the different diameter wire measured by the noncontact external-diameter measuring instrument are obtained at the same time. A length of the narrow diameter part and / or the taper part of the different diameter wire is determined on the basis of a relationship of the displacement and the external diameter obtained at each of the plurality of shafts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a method for measuring the shape of a wire with a variable diameter.

Background Art

[0002] A wire with a variable diameter is obtained by processing round wires or round bars such as metal wires, resin-coated metal wires, resin tubes, and resin rods. In addition to thick outer diameter parts (thick diameter parts) without undergoing processing, it has thin outer diameter parts (thin diameter parts), tapered parts (taper parts), or both of these.

[0003] Conventionally, the shape of a wire with a variable diameter has been measured as follows. First, an operator measures the outer diameter at a plurality of locations along the axial direction of the wire with a variable diameter using a contact type measuring instrument such as a micrometer. Next, based on the variation in the outer diameter value or a specific outer diameter value, the starting position of processing (the bending position of the outer diameter) is specified. Further, a reference line is drawn with an oil-based pen or the like at the specified starting position, and the length between each reference line is measured with a metal ruler to determine the length along the axial direction of the thin diameter part or the taper part.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when using a contact measuring instrument as described above, the following problems occur. That is, when measuring with a contact measuring instrument, deformation and crushing of the non-uniform diameter line, which is the object to be measured, occur, so it is difficult to maintain the original dimensions and shape of the non-uniform diameter line before measurement, and moreover, the measured values may vary each time measurement is performed. In addition, when the original flattening of the non-uniform diameter line is combined with the deformation during the above measurement, it becomes difficult to specify the starting position of processing (the bending position of the outer diameter), and variations in judgment also occur among measurers. For this reason, it becomes difficult to accurately measure the shape of the non-uniform diameter line including the lengths of the small diameter portion and the taper portion.

[0006] An object of the present invention is to provide a method capable of accurately measuring the shape including the lengths of the small diameter portion and the taper portion of a non-uniform diameter line.

Means for Solving the Problems

[0007] According to the method for measuring the shape of a non-uniform diameter line according to the embodiment, (i) a plurality of non-contact outer diameter measuring instruments for measuring the outer diameter of the non-uniform diameter line on a plurality of axes of the non-uniform diameter line are arranged for a non-uniform diameter line having a small diameter portion and / or a taper portion in addition to a large diameter portion, (ii) the plurality of non-contact outer diameter measuring instruments are moved along the axial direction of the non-uniform diameter line from the measurement start position at one end to the measurement end position at the other end, (iii) for each of the plurality of axes, the displacement of the non-contact outer diameter measuring instrument from the measurement start position along the axial direction of the non-uniform diameter line and the outer diameter of the non-uniform diameter line measured by the non-contact outer diameter measuring instrument are simultaneously obtained, and (iv) based on the relationship between the displacement and the outer diameter obtained for each of the plurality of axes, the lengths of the small diameter portion and / or the taper portion of the non-uniform diameter line are determined.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

DETAILED DESCRIPTION OF THE INVENTION

[0009] A method for measuring the shape of a non-uniform diameter wire according to an embodiment will be described with reference to the drawings.

[0010] (i) First, for a non-uniform diameter wire having a small diameter portion and / or a taper portion in addition to a large diameter portion, a plurality of non-contact outer diameter measuring devices for measuring the outer diameter of the non-uniform diameter wire on a plurality of axes of the non-uniform diameter wire are arranged.

[0011] An example of a non-uniform diameter wire is shown in FIG. 1. The non-uniform diameter wire 10 shown in FIG. 1 has a large diameter portion 1, a short taper portion 2, a small diameter portion 3, a long taper portion 4, and a large diameter portion 5 along the direction from one end to the other end. This non-uniform diameter wire 10 is formed by processing the central portion of a round wire (round bar) having the same outer diameter as the large diameter portions 1 and 5 to form the short taper portion 2, the small diameter portion 3, and the long taper portion 4. The small diameter portion and / or the taper portion is not limited to the shape in FIG. 1 and can be arbitrarily formed according to the application.

[0012] In FIG. 1, the starting position of the processing (the bending position of the outer diameter) is indicated as A between the large diameter portion 1 and the short taper portion 2, B between the short taper portion 2 and the small diameter portion 3, C between the small diameter portion 3 and the long taper portion 4, and D between the long taper portion 4 and the large diameter portion 5.

[0013] FIG. 2 is an end view of the non-uniform diameter wire of FIG. 1, showing a state where a plurality of non-contact outer diameter measuring devices for measuring the outer diameter of the non-uniform diameter wire on a plurality of axes of the non-uniform diameter wire are arranged around the non-uniform diameter wire 10.

[0014] As a non-contact outer diameter measuring device, for example, a laser outer diameter measuring device (laser micro gauge) is used. The laser outer diameter measuring device has a light projecting unit including a light source and an optical system, and a light receiving unit including an optical system and a light receiving element. To measure the outer diameter of a non-uniform diameter wire, which is the object to be measured, using the laser outer diameter measuring device, the non-uniform diameter wire is held between the light projecting unit and the light receiving unit. Then, the laser light from the light source of the light projecting unit is irradiated through the optical system over a range covering the outer diameter of the non-uniform diameter wire. Based on the size of the area not received by the optical system and the light receiving element of the light receiving unit due to the non-uniform diameter wire blocking the light, the outer diameter of the non-uniform diameter wire is measured.

[0015] In FIG. 2, as an example, it is assumed that the non-uniform diameter wire 10 is held horizontally, and a laser outer diameter measuring device for measuring the outer diameter of the non-uniform diameter wire 10 with the horizontal axis as one axis of the non-uniform diameter wire 10, that is, the light projecting unit 21H and the light receiving unit 22H of the horizontal axis, and a laser outer diameter measuring device for measuring the outer diameter of the non-uniform diameter wire 10 with the vertical axis as the other axis of the non-uniform diameter wire 10, that is, the light projecting unit 21V and the light receiving unit 22V of the vertical axis, are arranged. FIG. 1 shows the light projecting unit 21V and the light receiving unit 22V of the vertical axis arranged at the measurement start position at one end, and the light projecting unit 21H and the light receiving unit 22H of the horizontal axis are not shown.

[0016] Note that, for example, three non-contact outer diameter measuring devices for measuring the outer diameter of the non-uniform diameter wire at intervals of 120° around the axis of the non-uniform diameter wire may be arranged, and the number of non-contact outer diameter measuring devices arranged can be appropriately changed according to the number of multiple axes.

[0017] (ii) Next, a plurality of non-contact outer diameter measuring devices are moved along the axial direction of the non-uniform diameter wire from the measurement start position at one end to the measurement end position at the other end.

[0018] A plurality of non-contact outer diameter measuring devices are fixed to a movable part of an actuator (not shown) having a main body and a movable part, for example. By driving the movable part by the main body of the actuator, the plurality of non-contact outer diameter measuring devices can be moved along the axial direction of the different-diameter line from the measurement start position at one end to the measurement end position at the other end. The plurality of non-contact outer diameter measuring devices may be moved simultaneously or separately. In FIG. 1, the light projecting part 21V and the light receiving part 22V of the vertical axis after movement are shown by a two-dot chain line.

[0019] (iii) Next, for each of the plurality of axes (here, the horizontal axis and the vertical axis), the displacement of the non-contact outer diameter measuring device from the measurement start position along the axial direction of the different-diameter line and the outer diameter of the different-diameter line measured by the non-contact outer diameter measuring device are obtained simultaneously. As shown in FIG. 1, when focusing on the light projecting part 21V and the light receiving part 22V of the vertical axis, the distance from the measurement start position (P 0 ) at one end to an arbitrary measurement position (P x ) after movement becomes the displacement x of the non-contact outer diameter measuring device from the measurement start position along the axial direction of the different-diameter line 10, and the value of this displacement corresponds to the length of the different-diameter line 10 from the measurement start position at one end to an arbitrary measurement position. The displacement x of the non-contact outer diameter measuring device from the measurement start position along the axial direction of the different-diameter line 10 can be measured by, for example, an encoder attached to the actuator.

[0020] (iv) Further, based on the relationship between the displacement x of the non-contact outer diameter measuring device at an arbitrary measurement position and the outer diameter y of the different-diameter line 10 at that measurement position obtained for each of the plurality of axes (here, the horizontal axis and the vertical axis), the length along the axial direction of the narrow-diameter part and / or the tapered part of the different-diameter line is determined.

[0021] For example, by using spreadsheet software or other application software, a graph is created with the displacement x of the non-contact outer diameter measuring instrument on the horizontal axis and the outer diameter y of the stepped diameter line 10 on the vertical axis to visualize the stepped diameter portion, and the shapes of the outer surfaces of the short taper portion 2, the small diameter portion 3, and the long taper portion 4 can be represented by mathematical formulas of approximate straight lines. Further, the x-coordinates of the intersections of the mathematical formulas representing the approximate straight lines corresponding to the shapes of the outer surfaces of the obtained short taper portion 2, small diameter portion 3, and long taper portion 4, that is, the x-coordinates of the starting positions (outer diameter bending positions) A, B, C, and D shown in FIG. 1 can be obtained. Then, from the differences in the x-coordinates between A and B, between B and C, and between C and D, the lengths along the axial direction of the short taper portion 2, the small diameter portion 3, and the long taper portion 4 can be determined.

[0022] As described above, according to the method for measuring the shape of the stepped diameter line according to the embodiment, since a non-contact outer diameter measuring instrument is used, problems due to deformation and crushing of the stepped diameter line can be avoided, and moreover, by adopting specific rules for calculation processing and the like, variations in judgment by the measurer can be eliminated, and the shape including the lengths of the small diameter portion and the taper portion of the stepped diameter line can be accurately measured.

Example

[0023] Hereinafter, an example according to the present invention will be described. (Example 1) A stepped diameter line 10 having the shape shown in FIG. 1 was prepared. This stepped diameter line 10 is a silver-plated copper wire, and is processed with a design having an outer diameter of 0.50 mm for the thick diameter portions 1 and 5, an outer diameter of 0.40 mm for the small diameter portion 3, a length of 5 mm for the short taper portion 2, a length of 300 mm for the small diameter portion 3, and a length of 50 mm for the long taper portion 4.

[0024] As shown in FIGS. 1 and 2, the stepped diameter line 10 was held horizontally, and the light projecting portion 21H and the light receiving portion 22H of the laser outer diameter measuring instrument for measuring the outer diameter of the stepped diameter line 10 about the horizontal axis of the stepped diameter line 10, and the light projecting portion 21V and the light receiving portion 22V of the laser outer diameter measuring instrument for measuring the outer diameter of the stepped diameter line 10 about the vertical axis of the stepped diameter line 10 were arranged. The plurality of laser outer diameter measuring instruments are fixed to the movable part of an actuator (not shown).

[0025] The light projecting part 21H and the light receiving part 22H of these laser outer diameter measuring devices for the horizontal axis, and the light projecting part 21V and the light receiving part 22V of the laser outer diameter measuring device for the vertical axis are moved along the axial direction of the different diameter line 10 from the measurement start position at one end to the measurement end position at the other end by the main body of an actuator (not shown).

[0026] For each of the horizontal axis and the vertical axis, the displacement x of the laser outer diameter measuring device from the measurement start position along the axial direction of the different diameter line 10 and the outer diameter y of the different diameter line measured by the laser outer diameter measuring device are obtained simultaneously. The measurement pitch is 1 mm.

[0027] Figure 3 is a graph showing the relationship between the measured displacement x of the laser outer diameter measuring device and the outer diameter y of the different diameter line, which is displayed by spreadsheet software. In Figure 3, the curve marked with H shows the relationship between the displacement x and the outer diameter y on the horizontal axis, and the curve marked with V shows the relationship between the displacement x and the outer diameter y on the vertical axis. Also, Figure 3 shows a curve indicating the average value of the curve H on the horizontal axis and the curve V on the vertical axis. As shown in Figure 3, particularly in the small diameter part 3 and the long taper part 4, the difference between the curve H and the curve V is large, and it can be seen that large flattening occurs in these parts compared to other parts.

[0028] Figure 4 is a graph showing the curve indicating the average value of the curve H and the curve V in Figure 3, and the approximate straight lines corresponding to the outer surface shapes of the large diameter parts 1, 5, the short taper part 2, the small diameter part 3, and the long taper part 4 respectively. These approximate straight lines can also be obtained by spreadsheet software.

[0029] The outer surfaces of the large diameter parts 1, 5 are represented by a horizontal line corresponding to the average value of the outer diameters of the large diameter parts, which is 0.505 mm. The outer surface of the short taper part 2 is represented by the following approximate straight line (L2). y = -0.032250x + 1.536833 … (L2). The outer surface of the small diameter part 3 is represented by the following approximate straight line (L3). This approximate straight line is close to the horizontal line corresponding to the designed dimension of the outer diameter of the small diameter part 3, which is 0.40 mm. y = -0.000005E+0.400454 … (L3). The outer surface of the long tapered portion 4 is represented by an approximate straight line (L4) of the following formula. y = 0.002231x - 0.348778 … (L4).

[0030] Also, FIG. 4 shows the intersection point A of the horizontal line corresponding to the large diameter portion 1 and the approximate straight line (L2), the intersection point B of the approximate straight line (L2) and the approximate straight line (L3), the intersection point C of the approximate straight line (L3) and the approximate straight line (L4), and the intersection point D of the approximate straight line (L4) and the horizontal line corresponding to the large diameter portion 5.

[0031] The x - coordinates and y - coordinates of the intersection points A, B, C, and D were as shown in Table 1 below.

[0032]

Table 1

[0033] As shown in FIG. 4, from the differences in the x - coordinates between A - B, B - C, and C - D, the lengths along the axial direction of the short tapered portion 2, the small diameter portion 3, and the long tapered portion 4 can be determined.

[0034] As a result, the lengths of each part were calculated as follows. Short tapered portion 2: 3 mm Small diameter portion 3: 300 mm Long tapered portion 4: 47 mm. (Comparative Example 1) For comparison, an operator used a micrometer to measure the outer diameter at multiple locations along the axial direction of the same stepped wire as used in Example 1, identified the starting position of the machining, drew a marking line with an oil - based pen at the identified starting position, measured the length between each marking line with a scale, and determined the lengths of the short tapered portion 2, the small diameter portion 3, and the long tapered portion 4. The results were as follows.

[0035] Short tapered portion 2: 6 mm Small diameter portion 3: 298 mm Long tapered portion 4: 50 mm.

[0036] Thus, the lengths of each part determined by the method using a micrometer deviated from the lengths of each part determined by the method of Example 1, and moreover, it was predicted that variations would occur depending on the measurer. According to the method for measuring the shape of a stepped diameter line by the method of Example 1, the shape including the lengths of the narrow diameter part and the tapered part of the stepped diameter line can be accurately measured. (Example 2) The stepped diameter line 10 having the same shape, size, and material as in Example 1 was used as the measurement target, and the measurement by the method using the same non-contact outer diameter measuring instrument as in Example 1 was repeated. In addition, for one stepped diameter line to be measured, the measurement was repeated 5 times. The measured values (mm) of each part (short tapered part, narrow diameter part, long tapered part, total length of stepped diameter processed part), the average of the measured values of each part (mm), the maximum value of the measured values of each part (mm), the minimum value of the measured values of each part (mm), the difference between the maximum value and the minimum value (mm), the coefficient of variation [%], and the standard deviation are shown in Table 2. Here, the coefficient of variation [%] = {(maximum - minimum) / (average value)} x 100.

[0037]

Table 2

[0038] (Comparative Example 2) The stepped diameter line 10 having the same shape, size, and material as in Example 1 was used as the measurement target, and the measurement by the method using the same micrometer as in Comparative Example 1 was repeated. In addition, for one stepped diameter line to be measured, the measurement was repeated 5 times. The measured values (mm) of each part (short tapered part, narrow diameter part, long tapered part, total length of stepped diameter processed part), the average of the measured values of each part (mm), the maximum value of the measured values of each part (mm), the minimum value of the measured values of each part (mm), the difference between the maximum value and the minimum value (mm), the coefficient of variation [%], and the standard deviation are shown in Table 3. Here, the coefficient of variation [%] = {(maximum - minimum) / (average value)} x 100.

[0039]

Table 3

[0040] From the comparison between Table 2 and Table 3, according to the method of Example 2 using a non-contact outer diameter measuring instrument, when repeated measurements were made, the variation in the measured values for all parts was small in five measurements. On the other hand, in the method of Comparative Example 2 of contact measurement using a micrometer, a tendency for the variation in results to increase was observed in repeated measurements. (Example 3) The stepped wire 10 with the same shape, size, and material as in Example 1 was used as the measurement object, and the measurement using the same non-contact outer diameter measuring instrument as in Example 1 was performed by three persons A, B, and C. The measured values (mm) by each of A, B, and C for each part (short taper part, small diameter part, long taper part, total length of stepped part), the average of the measured values for each part (mm), the maximum value of the measured values for each part (mm), the minimum value of the measured values for each part (mm), the difference between the maximum value and the minimum value (mm), the coefficient of variation [%], and the standard deviation are shown in Table 4. Here, the coefficient of variation [%] = {(maximum - minimum) / (average value)} x 100.

[0041]

Table 4

[0042] (Comparative Example 3) The stepped wire 10 with the same shape, size, and material as in Example 1 was used as the measurement object, and the measurement using the same micrometer as in Comparative Example 1 was performed by three persons A, B, and C. The measured values (mm) by each of A, B, and C for each part (short taper part, small diameter part, long taper part, total length of stepped part), the average of the measured values for each part (mm), the maximum value of the measured values for each part (mm), the minimum value of the measured values for each part (mm), the difference between the maximum value and the minimum value (mm), the coefficient of variation [%], and the standard deviation are shown in Table 5. Here, the coefficient of variation [%] = {(maximum - minimum) / (average value)} x 100.

[0043]

Table 5

[0044] From the comparison between Table 4 and Table 5, according to the method of Example 3 using a non-contact outer diameter measuring instrument, the variation in results by the measurer is small at any site. On the other hand, in the method of Comparative Example 3 of contact measurement using a micrometer, although each of A, B, and C carried out the measurement according to the same measurement rule, the measured values varied. This is presumably due to the flattening and deformation of the different-diameter line, and there is a difference in the judgment of the processing start and end positions by the measurer. The non-contact measurement method of the example is a more useful measurement method because almost the same measurement result can be obtained no matter who measures. Also, there is an advantage that it can be measured simply and in a short time regardless of the proficiency of the measurer.

[0045] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Explanation of Reference Signs

[0046] 1... large-diameter part, 2... short taper part, 3... small-diameter part, 4... long taper part, 5... large-diameter part, 10... different-diameter line, 21H, 21V... light-projecting part, 22H, 22V... light-receiving part.

Claims

1. For a non-uniform diameter wire having a thin diameter portion and / or a tapered portion in addition to a large diameter portion, a plurality of non-contact outer diameter measuring devices for measuring the outer diameter of the non-uniform diameter wire on a plurality of axes of the non-uniform diameter wire are arranged, The plurality of non-contact outer diameter measuring devices are moved along the axial direction of the non-uniform diameter wire from a measurement start position at one end to a measurement end position at the other end, For each of the plurality of axes, the displacement of the non-contact outer diameter measuring device from the measurement start position along the axial direction of the non-uniform diameter wire and the outer diameter of the non-uniform diameter wire measured by the non-contact outer diameter measuring device are simultaneously obtained, Based on the relationship between the displacement and the outer diameter obtained for each of the plurality of axes, the length of the thin diameter portion and / or the tapered portion of the non-uniform diameter wire is determined, A method for measuring the shape of a non-uniform diameter wire.

2. The method for measuring the shape of a non-uniform diameter wire according to claim 1, wherein the non-contact outer diameter measuring device is a laser outer diameter measuring device.

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