Measurement device and molding machine

Abstract

To provide a technique that enables more accurate image processing-based measurement compared with conventional techniques.SOLUTION: A measurement device 20A according to an embodiment is equipped with a camera 24 for capturing an image of a compression coil spring 91 molded by a molding machine 10A in the air. An image processing unit 62A then performs image processing on an image of the compression coil spring 91 captured by the camera 24 to measure dimensions of the compression coil spring 91.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a measuring device that measures the dimensions of a workpiece or the degree of conformity with a master workpiece, and a molding machine equipped with such a measuring device. [Background technology]

[0002] 2. Description of the Related Art Known conventional measuring devices are those that measure the dimensions of a workpiece by imaging the workpiece with a camera and processing the image obtained (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5666954 (paragraph

[0020] , Figure 2) Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the conventional measuring devices described above, problems can occur such as the support member that supports the workpiece when it is imaged appearing in the image in a way that hides part of the workpiece, or the support member being mistakenly recognized as part of the workpiece during image processing, making it impossible to perform accurate measurements, and there is a demand for the development of technology to solve these problems. [Means for solving the problem]

[0005] One aspect of the invention is a measuring device that includes a camera for capturing images in the air of a workpiece manufactured by industrial machinery, and an image processing unit that performs image processing on the image of the workpiece captured by the camera to measure the dimensions of the workpiece or its degree of correspondence with a master workpiece. Effect of the Invention

[0006] In one embodiment of the measuring device of the invention, the dimensions of the workpiece or the degree of match with a master workpiece are measured by image processing of the image obtained by photographing the workpiece in the air, thereby preventing the occurrence of problems such as a support member supporting the workpiece appearing in the image and being mistakenly recognized as part of the workpiece or part of the workpiece being hidden by the support member, as was the case in the conventional method, and making it possible to perform measurements using image processing more accurately than before. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view of a molding machine according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of the coiling tool, pitch tool, etc. of the molding machine. [Diagram 3] Figure 3 shows the controller block diagram. [Figure 4] FIG. 4A is a side view of the wire and the tools just before being formed into a compression coil spring, FIG. 4B is a side view of the wire and the tools in the initial stage of forming, and FIG. 4C is a side view of the wire and the tools in the middle of forming. [Diagram 5] FIG. 5A is a side view of the wire and tools in the final stage of forming, and FIG. 5B is a side view of the compression coil spring being separated from the subsequent wire. [Figure 6] FIG. 6A is a side view of a compression coil spring immediately after forming, and FIG. 6B is a side view of a compression coil spring that has been completed through a grinding process. [Figure 7] Figure 7 is a side cross-sectional view of the molding machine. [Figure 8] Figure 8 is a front cross-sectional view of the measurement device. [Figure 9] FIG. 9A is an image of measuring the outer diameter from an image of a compression coil spring, FIG. 9B is an image of measuring the total length from an image of a compression coil spring, and FIG. 9C is an image of measuring the pitch from an image of a compression coil spring. [Figure 10] FIG. 10 is a cross-sectional plan view of a measurement device according to the second embodiment. [Figure 11]11A and 11B relate to the third embodiment. FIG. 11A is an image of a master work, and FIG. 11B is an image of a compression coil spring captured by a camera superimposed on the image of the master work. [Figure 12] FIG. 12 is an image diagram showing how dimensions are measured from an image of a compression coil spring according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [First embodiment] A molding machine 10A according to this embodiment will be described with reference to Figures 1 to 9. As shown in Figure 1, the molding machine 10A includes a vertically standing base 11, on which are mounted a wire feeder 33, a pair of pitch / cutting slide mechanisms 30A, 30B, a pair of coiling slide mechanisms 40A, 40B, a measuring device 20A (see Figure 7), and the like.

[0009] The wire feeder 33 is provided with a pair of rollers 34 arranged vertically on the front surface of the base 11. As shown in Fig. 1, the wire guide 12 extends on a common tangent line of the pair of rollers 34. The pair of rollers 34 are symmetrically rotated by a servo motor 35 (see Fig. 3) with the wire 90 sandwiched therebetween, whereby the wire 90 is fed to the right side in Fig. 1, passes through a through hole 12A (see Fig. 4A) of the wire guide 12, and is sent out from the tip of the wire guide 12.

[0010] In front of the wire guide 12 in the wire feed direction, a core bar 13 is provided, which protrudes from the front surface of the base 11. As shown in Fig. 2, the core bar 13 is, for example, rod-shaped with a semicircular cross section, and its flat side surface 13A faces the wire guide 12 side.

[0011] 1, the pair of coiling slide mechanisms 40A, 40B are disposed on the side farther from the wire feeder 33 than the core 13 and extend in a direction inclined with respect to the vertical direction. The coiling slide mechanisms 40A, 40B are each equipped with a crank slider mechanism 40K including a slider 41 that moves toward and away from the core 13, and are driven by servo motors 42A, 42B (see FIG. 3).

[0012] A pair of coiling tools 16A, 16B are fixed to sliders 41 of a pair of coiling slide mechanisms 40A, 40B. As shown in Fig. 2, one coiling tool 16A is butted against the core metal 13 from diagonally above, and the other coiling tool 16B is butted against the core metal 13 from diagonally below. A round groove 16M is formed on the tip surface of each of the coiling tools 16A, 16B. Then, a wire 90 fed from a wire feeder 33 is guided by the round groove 16M of each of the coiling tools 16A, 16B, and the wire 90 is formed into an arc shape so as to surround the core metal 13 and become a compression coil spring 91 (see Fig. 4C), and the compression coil spring 91 grows in a direction away from the base 11.

[0013] 1, the pair of pitch / cutting slide mechanisms 30A, 30B extend in the vertical direction and are arranged symmetrically above and below with the core bar 13 therebetween. Each of the pitch / cutting slide mechanisms 30A, 30B has a crank slider mechanism 30K including a slider 31 that slides in the vertical direction, and is driven by servo motors 32A, 32B.

[0014] A cutting tool 15 is fixed to the slider 31 of the upper pitch / cutting slide mechanism 30A, and the wire 90 is cut by the cutting tool 15 and the mandrel 13. On the other hand, a pitch tool 14 is fixed to the slider 31 of the lower pitch / cutting slide mechanism 30B. As shown in FIG. 2, the tip of the pitch tool 14 is wedge-shaped and has an inclined surface 14A. The inclined surface 14A abuts against the wire 90 constituting the compression coil spring 91 from the base 11 side. When the pitch tool 14 is moved upward, the pitch of the compression coil spring 91 becomes larger, and when the pitch tool 14 is moved downward, the pitch of the compression coil spring 91 becomes smaller.

[0015] 3 shows a controller 43 for controlling the molding machine 10A. The controller 43 includes servo amplifiers for the servo motors 32A, 32B, 35, 42A, and 42B, and a control circuit 44 to which the servo amplifiers are connected. The control circuit 44 includes a CPU 45A, a RAM 45B, a ROM 45C, and a flash memory 45D. The CPU 45A executes a spring forming program (not shown) stored in the ROM 45C to drive and control the servo motors 32A, 32B, 35, 42A, and 42B, thereby sequentially forming compression coil springs 91 from the wire rod 90.

[0016] Specifically, in the spring forming program, for example, a plurality of division points are set by dividing the feeding length of one compression coil spring 91 fed by the wire feeder 33, and the positions of the coiling tools 16A, 16B, the pitch tool 14, and the cutting tool 15 are taught for each division point. Then, by executing the spring forming program, the wire feeder 33, the coiling tools 16A, 16B, the pitch tool 14, and the cutting tool 15 operate as follows by so-called teaching playback.

[0017] That is, from a state in which the wire 90 is cut by the cutting tool 15 and the mandrel 13 (see FIG. 4A), the wire feeder 33 feeds the wire 90 at a preset feeding speed. Then, the fed wire 90 collides with the inner surface of the round groove 16M of the coiling tools 16A, 16B and slides against the inclined surface 14A of the pitch tool 14 to be formed into an arc shape (see FIG. 2). In detail, in the initial stage of spring forming, as shown in FIGS. 4A and 4B, the pitch tool 14 is disposed at a first forming position slightly elevated from the initial position, and in this state, one turn of the wire 90 is fed to form an end turn 91A on the tip side.

[0018] Next, as shown in Fig. 4B and Fig. 4C, the pitch tool 14 rises from the first forming position to the second forming position, and in this state, multiple turns of the wire 90 are fed to form the coil body 91B. Then, as shown in Fig. 4C to Fig. 5A, the pitch tool 14 descends to the first forming position again, and one turn of the wire 90 is fed to form the end turn 91C on the rear end side. Then, after the pitch tool 14 retreats to a standby position separated from the compression coil spring 91, the cutting tool 15 descends from the initial position, and the compression coil spring 91 is separated from the succeeding wire 90 (see Fig. 5B). Then, the group of tools including the coiling tools 16A and 16B, the pitch tool 14, and the cutting tool 15 return to their initial positions (see Fig. 4A).

[0019] 6A shows an enlarged view of the compression coil spring 91 discharged from the molding machine 10A. The compression coil spring 91 is then sent to a grinding process, and both end faces are ground by a spring grinding device disclosed in, for example, Japanese Patent No. 6964956, Japanese Patent Application Publication No. 2019-084643, etc. Then, as shown in FIG. 6B, the compression coil spring 91 has a pair of end faces 91Z at both ends that are perpendicular to the winding center axis CL (see FIG. 9), and the grinding process ends when the distance between the pair of end faces 91Z becomes a preset spring length L1, and the compression coil spring 91 is completed.

[0020] As shown in Figs. 7 and 8, the measuring device 20A has a work guide 23 and a camera 24 (the measuring device 20A is omitted in Fig. 1). The work guide 23 includes, for example, a guide bar 21 and a guide pipe 22. The guide bar 21 is formed by bending two points in the longitudinal direction of a round bar. A starting end 21A of the guide bar 21 is connected to the tip surface of the core bar 13 and extends so as to incline slightly downward as it moves away from the core bar 13, and a middle part 21B of the guide bar 21 is bent from the end of the starting end 21A and extends so as to incline downward at a steeper angle than the starting end 21A, and a terminal end 21C of the guide bar 21 is bent from the end of the middle part 21B and extends vertically downward.

[0021] The guide pipe 22 extends vertically as a whole, has a tapered section 22A at its upper end, which expands in diameter toward the top, and a straight section 22B with a uniform inner diameter below the tapered section 22A. The guide pipe 22 is disposed coaxially below the terminal end 21C of the guide bar 21, and the lower end of the guide bar 21 is butted against the upper opening of the guide pipe 22. Further, a through hole 22C is formed near the lower end of the guide pipe 22, penetrating from the side to the inside and outside, and is covered by a sensor 50 fixed to the outer surface of the guide pipe 22. When the lower end of the compression coil spring 91 passes in front of the through hole 22C, the sensor 50 detects this.

[0022] The sensor 50 may be of any type so long as it is non-contact, and may be, for example, any of an optical type, a magnetic type, an electric field type, a capacitance type, etc. The sensor 50 may be disposed above or below the guide pipe 22. Furthermore, the terminal end 21C of the guide bar 21 may be received inside the guide pipe 22. The guide bar 21 may be a solid rod or a hollow rod (i.e., a pipe).

[0023] The guide pipe 22 is supported by a base portion 26, which is supported by a bracket 27 fixed to the front surface of the base 11. Although the details of the bracket 27 are not shown, the bracket 27 has a structure in which a support plate is bridged between the tips of a pair of opposing walls that laterally sandwich the lower end portion of the lower pitch / cutting slide mechanism 30B. The base portion 26 is fixed to the front surface of the bracket 27 that faces away from the base 11.

[0024] 8, the base portion 26 includes, for example, a horizontally elongated portion 26B extending in the wire feeding direction of the wire 90 (hereinafter referred to as the "horizontal direction" as appropriate) when viewed from the front, a forward protruding portion 26A protruding forward from one end of the horizontally elongated portion 26B, and an upward protruding portion 26C protruding upward from the other end of the horizontally elongated portion 26B. The camera 24 is attached to the end of the horizontally elongated portion 26B on the side having the upward protruding portion 26C.

[0025] The camera 24 is, for example, a CCD camera or a CMOS camera with a telecentric lens, and the front surface of the camera 24 (i.e., the surface having the lens) faces the forward protrusion 26A with a gap therebetween. The camera 24 may be any type as long as it can capture an image as digital data.

[0026] A support beam 26D is fixed to the upper front surface of the upward protruding portion 26C, and the guide pipe 22 is supported by the support beam 26D. The lower end of the guide pipe 22 is located directly above the front region R2 of the camera 24 (specifically, the region surrounded on three sides by the camera 24, the forward protruding portion 26A, and the horizontally elongated portion 26B). As a result, as shown in FIG. 7, the compression coil spring 91 formed in the forming region R1 of the molding machine 10A is guided by the work guide 23 to descend to a position above the front region R2 of the camera 24, and then falls freely from there and passes through the front region R2 of the camera 24. At this time, the camera 24 operates based on the detection result of the sensor 50, and the compression coil spring 91 in the air is imaged by the camera 24.

[0027] A container (not shown) is provided below the front region R2 of the camera 24, and the compression coil spring 91 that has passed the front region R2 of the camera 24 is housed in this container and transported to the grinding process described above. Instead of the container, for example, a bar or pipe extending in the vertical direction may be provided, into which the compression coil spring 91 is fitted.

[0028] 8, a backlight 29 is provided on the surface of the forward protrusion 26A facing the camera 24. Specifically, the forward protrusion 26A has, for example, a rectangular cylindrical shape and has a light emitting substrate 29A inside. A through hole 29B is formed on the surface of the forward protrusion 26A facing the camera 24, and the through hole 29B is covered with, for example, a translucent member 29C of an opaque white color. As a result, a part of the forward protrusion 26A serves as the backlight 29, and the backlight 29 emits light when the camera 24 captures an image of the compression coil spring 91, thereby making the boundary between the compression coil spring 91 and other portions clear.

[0029] The measuring device 20A has a control unit 60 connected to the controller 43 as shown in FIG. 3. The control unit 60 has a control circuit 62 including, for example, a CPU 62A, a RAM 62B, a ROM 62C, and a flash memory 62D. The CPU 62A executes an imaging program stored in the ROM 62C upon startup of the molding machine 10A. Then, upon receiving the detection result of the sensor 50, the CPU 62A operates the camera 24 at the timing when the compression coil spring 91 passes through the front area R2 of the camera 24 as described above. Then, the image of the compression coil spring 91 captured by the camera 24 is stored in the flash memory 62D.

[0030] When the image is captured into the flash memory 62D, the CPU 62A executes an image processing program stored in the ROM 62C. When executing this image processing program, the CPU 62A becomes an "image processing unit" of the measuring device 20A.

[0031] The CPU 62A as an image processing unit performs the following image processing on the image of the compression coil spring 91 illustrated in Fig. 9A to Fig. 9C. That is, a plurality of pixels (each pixel is omitted in Fig. 9A to Fig. 9C) constituting the image are distinguished into black pixels corresponding to the compression coil spring 91 and white pixels corresponding to the background, and the contour of the compression coil spring 91 is identified. Then, this image (hereinafter, appropriately referred to as "target image") is pattern-matched with the standard image stored in the ROM 62C, and the outer diameter D of the compression coil spring 91 is first identified. Specifically, first, four square frames A1 to A4 shown in Fig. 9A registered in the standard image are set in the target image, and the outermost points B1 to B4 in the left-right direction in Fig. 9A are obtained within each of the frames A1 to A4. Next, a straight line Y1 is obtained by connecting point B1 in the upper left frame with point B2 in the lower left frame, and a straight line Y2 is obtained by connecting point B3 in the upper right frame with point B4 in the lower right frame. The distance between the straight lines Y1 and Y2 is then specified as the outer diameter D of the compression coil spring 91 and stored in the flash memory 62D.

[0032] Next, the total length L0 of the compression coil spring 91 is specified. Specifically, first, two upper and lower rectangular frames G1 and G2 shown in FIG. 9B registered in the standard image are set in the target image, and the outermost points J1 and J2 in the vertical direction of FIG. 9B are obtained within each frame G1 and G2. Next, vertical lines X1 and X2 passing through the points J1 and J2 and perpendicular to the straight lines Y1 and Y2 are obtained. Then, the distance between the vertical lines X1 and X2 is specified as the total length L0 of the compression coil spring, and is stored in the flash memory 62D.

[0033] Finally, the pitch of the compression coil spring 91 is specified. Specifically, first, a square frame K1 shown in FIG. 9C, which is registered in the standard image, is set in the target image. Next, straight lines Q1 to Q8 are obtained along the shape of each of the four bent portions of the compression coil spring 91 within the frame K1. Then, in the bent portion at the bottom of the frame K1, a midpoint F1 between the intersections of the straight lines Q1 and Q2 on the straight line Y1 is obtained, and a center line R1 parallel to the vertical lines X1 and X2 passing through the midpoint F1 is obtained. Similarly, midpoints F2 to F4 are obtained for the bent portions other than the bottom of the frame K1, and center lines R2 to R4 are obtained. Then, the distances between the adjacent center lines R1 to R4 are specified as pitches P1 to P3 of the compression coil spring 91, and are stored in the flash memory 62D.

[0034] When these measurement data groups are stored in the flash memory 62D, the quality control program stored in the ROM 62C is executed. When the image processing program is executed, the CPU 62A becomes the "quality control unit" of the measuring device 20A. Here, in the ROM 62C, for example, reference values ​​for each of the measurement data, such as the spring length L0, the outer diameter D, and the pitches P1 to P3, are preset in multiple stages. Then, the CPU 62A as the quality control unit displays different levels of notification, such as warning, caution, and abnormality, on the monitor 60M depending on which stage of the reference value each measurement data falls within. Also, for example, when any of the measurement data is at an abnormal level, an abnormality signal is output to the controller 43, and the molding machine 10A is stopped.

[0035] This completes the description of the configuration of this embodiment. As described above, in the measuring device 20A of this embodiment, the compression coil spring 91 is imaged in the air, the image is processed, and the dimensions of the compression coil spring 91 are measured. This prevents the support member that supports the compression coil spring 91 from appearing in the image and being mistakenly recognized as part of the compression coil spring 91, or the support member from hiding part of the compression coil spring 91, as in the conventional case, and makes it possible to perform measurements by image processing more accurately than in the conventional case.

[0036] In addition, the compression coil spring 91 discharged from the molding area R1 of the molding machine 10A is guided by the work guide 23 so as to descend to a position above the front area R2 of the camera 24, and then falls through the front area R2 of the camera 24, so that the posture of the compression coil spring 91 when imaged is stable, making it easier to measure dimensions, etc. by image processing.

[0037] The work guide 23 includes a curved, rod-shaped guide bar 21, and a starting end 21A of the guide bar 21 fits inside the compression coil spring 91 being molded and a terminal end 21C extends vertically, so that the compression coil spring 91 discharged from the molding area R1 of the molding machine 10A can be smoothly guided to a position directly above the front area R2 of the camera 24. Moreover, since the compression coil spring 91 falls through the front area R2 of the camera 24 with its central axis aligned vertically, it becomes easy to image the entire compression coil spring 91.

[0038] This embodiment also includes a guide pipe 22 that is arranged coaxially below the guide bar 21. The compression coil spring 91 passes through the inside of the guide pipe 22, so that the guide pipe 22 can be firmly supported from the outside. This provides guidance for the compression coil spring 91 at a position directly above the front region R2 of the camera 24, further stabilizing the posture of the compression coil spring 91 during imaging.

[0039] In addition, the guide pipe 22 is equipped with a sensor 50 that detects the passage of the compression coil spring 91, and the camera 24 operates according to the detection result by the sensor 50 to capture an image of the compression coil spring 91. This reduces the amount of image data generated by unnecessary capture in which the compression coil spring 91 is not captured, making it easier to store the images.

[0040] Also, since the camera 24 is provided with the backlight 29 arranged to face the camera from the front, it becomes easy to distinguish between the compression coil spring 91 and the background in the image of the compression coil spring 91, making it easy to measure the dimensions, etc. of the compression coil spring 91 through image processing. Furthermore, since the camera 24 is provided with a telecentric lens, the difference in how the compression coil spring 91 is captured between the side closer to the camera 24 and the side farther from the camera 24 is reduced, making it easy to measure the dimensions, etc. of the compression coil spring 91 through image processing.

[0041] Furthermore, the measuring device 20A is included in the molding machine 10A and sequentially measures the dimensions of the compression coil springs 91 that are sequentially molded, so that efficient measurement can be performed.

[0042] In the molding machine 10A of this embodiment, the measurement results by the measuring device 20A are used for quality control, but the control data of the group of tools by the molding machine 10A may be automatically changed based on the measurement results by the measuring device 20A. To achieve this, for example, as disclosed in Japanese Patent No. 5777184, a configuration may be used in which the dimensional management target portion is predicted by an autoregressive model and a correction amount is calculated.

[0043] In addition, for example, regression analysis by machine learning may be used. Specifically, for example, the control data of each tool group set by teaching is changed to various values ​​as explanatory variables, and the compression coil springs 91 are actually formed using the control data changed to various values. Then, the spring length L0, the outer diameter D, and the pitches P1 to P3 of the compression coil springs 91 are measured by the measuring device 20A, and the measurement results are used as objective variables for the explanatory variables described above to perform regression analysis by machine learning. Then, the learned model may be used to determine control data for forming the desired spring length L0, the outer diameter D, and the pitches P1 to P3.

[0044] [Second embodiment] The measuring device 20B of this embodiment is a modified example of the first embodiment, and includes a plurality of (for example, two) cameras 24 as shown in FIG. 10. The cameras 24 are adapted to capture images of the compression coil spring 91 from different directions. Specifically, the first camera 24 captures an image of the compression coil spring 91 from the lateral direction of the molding machine 10A as in the first embodiment, and the second camera 24 captures an image of the compression coil spring 91 from the front of the molding machine 10A. The backlight 29 is provided to face each of the pair of cameras 24. The control unit 60 (see FIG. 3) operates the pair of cameras 24 simultaneously. The CPU 62A as an image processing unit processes the images captured simultaneously by the pair of cameras 24 to measure the spring length L0 of the compression coil spring 91. In detail, the CPU 62A as an image processing unit obtains the inclination angle of the compression coil spring 91 in the lateral direction with respect to the up-down direction (hereinafter referred to as "lateral inclination angle") from the image captured by the second camera 24. Then, the spring length L0 and pitches P1 to P3 are obtained by correcting the shortened portion due to the above-mentioned lateral inclination angle in the image of the compression coil spring 91 captured from the lateral direction by the first camera 24. The outer diameter D is obtained in the same manner as in the first embodiment.

[0045] Thus, according to the configuration of this embodiment, the dimensions, etc. of the compression coil spring 91 are measured based on images captured simultaneously by multiple cameras 24, making it easy to identify the posture of the compression coil spring 91 at the time of imaging, and reducing measurement errors due to variations in the posture of the compression coil spring 91.

[0046] [Third embodiment] This embodiment is a modified example of the first and second embodiments, and is different from the above embodiments in that, as shown in FIG. 11, the size is not measured, but the degree of coincidence between the compression coil spring 91 and the master work 91M is measured. That is, in this embodiment, as shown in FIG. 11A, an image of the master work 91M having a target shape of the coil body 91B of the compression coil spring 91 is stored in the ROM 62C. Then, as shown in FIG. 11B, the CPU 62A as an image processing unit performs a process of overlapping the master work 91M (part indicated by a two-dot chain line) with the coil body 91B of the compression coil spring 91 (part indicated by black paint) captured by the camera 24, and obtains an overlapping area, which is the area of ​​the overlapping part. Then, the overlapping area is compared with a plurality of preset reference values, and a notification of different levels, such as a warning, a caution, or an abnormality, is displayed on the monitor 60M depending on which reference value the overlapping area is smaller than.

[0047] [Fourth embodiment] In this embodiment, the method of specifying the dimensions of the compression coil spring 91 is different from that of the first embodiment. Specifically, as shown in Fig. 12, when the contour of the compression coil spring 91 is specified by distinguishing between black pixels of the portion corresponding to the compression coil spring 91 and white pixels of the portion corresponding to the background, XY coordinate axes are set with a predetermined point of the image (for example, a point at the lower left corner of the image) as the origin, and position data of center points C(n) (n = 1, 2, 3, ...) of multiple semicircles appearing at the ends in the coil radial direction are specified. In addition, position data of edge points E1, E2 at both ends of the wire 90 that form the silhouette of a pointed protrusion at both ends of the compression coil spring 91 are also specified.

[0048] Next, a straight line SL1 close to a plurality of center points C(n) (C(1) to C(6), C(13) in FIG. 12) at one end in the radial direction of the compression coil spring 91 is specified by the least squares method, and a straight line SL2 is specified similarly for the remaining plurality of center points C(n) (C(7) to C(12) in FIG. 9). Then, a straight line that bisects the two straight lines SL1 and SL2 is specified as the center line CL. Then, new XY coordinate axes are set, with the center line CL of the compression coil spring 91 as the Y axis and a straight line perpendicular to the Y axis and passing through one edge point E2 as the X axis. On the new XY coordinate axes, a group of position data of the center point C(n) (n=1, 2, 3, . . .) and the edge points E1 and E2 are specified and stored in the flash memory 62D.

[0049] Next, using the position data group, the difference between the Y coordinate values ​​of the edge points E1 and E2 is calculated as the spring length L0. The average of the absolute values ​​of the X coordinate values ​​of the center points C(n) (n=1, 2, 3, . . .) is calculated, and the average is doubled to calculate the coil average diameter D. The standard deviation σ(r) of the absolute values ​​of the X coordinate values ​​of the center points C(n) (n=1, 2, 3, . . .) is also calculated. The pitch P(n) (n=1, 2, 3, . . .) shown in FIG. 12 is calculated from the difference between the Y coordinate values ​​of adjacent center points C(n) (n=1, 2, 3, . . .) and the average of the multiple pitches P(2) to P(5) and P(8) to P(10) in the coil body 91B is calculated as the pitch P, and the standard deviation σ(P) of the pitches P(2) to P(5) and P(8) to P(10) is also calculated.

[0050] [Other embodiments] The measuring device 20A in the first embodiment automatically and sequentially receives the compression coil springs 91 immediately after they are discharged from the molding area R1 of the molding machine 10A, but it may also be configured to receive multiple compression coil springs 91 that have been discharged and collected from the molding machine 10A in any order and at any timing.

[0051] The molding machine 10A of the first embodiment is for molding a compression coil spring 91, but the molding machine may be any industrial machine that manufactures a workpiece, such as a molding machine that presses sheet metal to draw or iron a workpiece, a processing machine that cuts or grinds a workpiece, or another type of machine.

[0052] The measuring devices 20A and 20B of the first and second embodiments measure the dimensions of the compression coil spring 91 based on two-dimensional images, but may be configured to identify a three-dimensional model of the work based on images captured simultaneously by multiple cameras, and measure the dimensions of the work or the degree of agreement with a master work from the three-dimensional model. With such a configuration, more detailed or accurate measurements can be performed than measurements that measure dimensions based on two-dimensional images.

[0053] The measuring device 20B of the second embodiment is configured to simultaneously image the compression coil spring 91 using two cameras 24, but it may also be possible to simultaneously image the compression coil spring 91 using three or more cameras 24. For example, three cameras may be arranged at positions that divide the circumferential direction around the drop area of ​​the compression coil spring 91 into thirds, and a backlight may be arranged between adjacent cameras to image the work from three directions, or eight cameras may be used to image the work in the air from four diagonally upward directions and four diagonally downward directions.

[0054] The measuring devices 20A and 20B in the above-described embodiment are provided with the backlight 29 facing the camera 24, but may be configured without the backlight 29.

[0055] <Additional Notes> The following describes the feature groups extracted from the above-described embodiments, while indicating their effects, etc., as necessary. Note that, in the following, for ease of understanding, the corresponding configurations in the above-described embodiments are appropriately indicated in parentheses, etc., but these feature groups are not limited to the specific configurations indicated in parentheses, etc.

[0056] [Feature 1] A measuring device (20A, 20B) including a camera (24) for imaging, in the air, a work (91) manufactured by an industrial machine (10A), and an image processing unit (62A) for performing image processing on the image of the work (91) imaged by the camera (24) to measure the dimensions of the work (91) or its degree of correspondence with a master work (91M).

[0057] According to the measuring device of feature 1, the workpiece is photographed in the air and the image obtained is processed to measure the dimensions of the workpiece or the degree of match with a master workpiece. This prevents the occurrence of problems such as a support member supporting the workpiece appearing in the image and being mistakenly recognized as part of the workpiece or part of the workpiece being hidden by the support member, as occurred in the conventional case, and makes it possible to perform measurements using image processing more accurately than before.

[0058] [Feature 2] The measuring device (20A, 20B) according to feature 1 includes a work guide (23) that guides the work (91) to descend from a molding area (R1) in which the work (91) is molded in a molding machine (10A), which is the industrial machine (10A), to a position above a forward area (R2) of the camera (24).

[0059] In the measuring device of feature 2, the workpiece discharged from the molding area of ​​the molding machine is guided by the work guide so that it descends to a position above the area in front of the camera, and then falls through the area in front of the camera. This stabilizes the posture of the workpiece when it is imaged, making it easy to measure dimensions, etc. through image processing.

[0060] [Feature 3] The measuring device (20A, 20B) according to feature 2, wherein the work (91) is a compression coil spring (91), and the work guide (23) includes a guide bar (21) having a curved rod shape, one end of which extends horizontally or in a direction inclined relative to the horizontal direction and fits inside the compression coil spring (91) being formed, and the other end of which extends vertically below the one end.

[0061] The work guide may have any structure suited to the shape of the work, but when the work is a compression coil spring, a structure including a curved rod-shaped guide bar like the work guide of the measuring device of Feature 3, with one end of the guide bar extending horizontally or in a direction inclined relative to the horizontal to fit inside the compression coil spring being formed and the other end extending vertically, can smoothly guide the compression coil spring discharged from the molding area of ​​the molding machine to a position directly above the area in front of the camera. Moreover, since the compression coil spring falls through the area in front of the camera with its central axis aligned vertically, it becomes easy to image the entire compression coil spring.

[0062] [Feature 4] The measuring device (20A, 20B) described in Feature 3, wherein the work guide (23) includes a guide pipe (22) having a pipe shape extending vertically and arranged coaxially below the other end of the guide bar (21).

[0063] When the workpiece is a compression coil spring, the guide bar of feature 3 may be the only workpiece guide; however, since the compression coil spring passes through the outside of the guide bar while being fitted thereto, the guide bar cannot support any part other than the upper end, which may cause a problem of the guide bar vibrating. In contrast, the measuring device of feature 4 is provided with a guide pipe arranged coaxially below the guide bar. Since the compression coil spring passes through the inside of the guide pipe, the compression coil spring can be firmly supported from the outside, and vibration is suppressed. As a result, the guide of the compression coil spring directly above the front area of ​​the camera provides guidance, and the posture of the compression coil spring during imaging is further stabilized.

[0064] [Feature 5] The measuring device (20A, 20B) according to feature 1, further comprising a sensor (50) that detects the passage of the workpiece (91) above the camera (24), the camera (24) operating in response to a detection result by the sensor (50) to capture an image of the workpiece (91).

[0065] According to the measuring device of Feature 5, the amount of image data caused by unnecessary capture of images that do not show the workpiece is reduced, making it easier to store the images.

[0066] [Feature 6] The measuring device (20A, 20B) according to feature 1, further comprising a backlight (29) arranged to face the camera (24) from the front.

[0067] In the measuring device of feature 6, the backlight makes it easy to distinguish between the workpiece and the background in the image of the workpiece, making it easy to measure the dimensions of the workpiece through image processing.

[0068] [Feature 7] The measuring device (20A, 20B) according to feature 1, wherein the camera (24) is provided with a telecentric lens.

[0069] In the measuring device of Feature 7, the camera is equipped with a telecentric lens, which reduces the difference in how the workpiece is captured between the side closer to the camera and the side farther away from the camera, making it easier to measure the workpiece dimensions, etc. through image processing.

[0070] [Feature 8] The measuring device (20A, 20B) described in feature 1, wherein a plurality of cameras (24) are provided and arranged so as to be able to capture images of the workpiece (91) from a plurality of directions, and the image processing unit (62A) measures the dimensions of the workpiece (91) or the degree of match with a master workpiece (91M) based on images captured simultaneously by the plurality of cameras (24).

[0071] In the measuring device of Feature 8, the dimensions of the workpiece are measured based on images captured simultaneously by multiple cameras, making it easy to identify the orientation of the workpiece at the time of image capture and reducing measurement errors due to variations in the orientation of the workpiece.

[0072] [Feature 9] The measuring device (20A, 20B) according to feature 8, wherein the image processing unit (62A) identifies a three-dimensional model of the work (91) based on images captured simultaneously by the multiple cameras (24), and measures the dimensions of the work (91) or the degree of agreement with a master work (91M) from the three-dimensional model.

[0073] The measuring device of Feature 9 identifies a three-dimensional model of the workpiece based on images captured simultaneously by multiple cameras, and measures the dimensions of the workpiece or its degree of match with a master workpiece from the three-dimensional model, thereby enabling more detailed or accurate measurements to be performed than those that measure dimensions, etc. based on two-dimensional images.

[0074] [Feature 10] A molding machine (10A) that sequentially molds a compression coil spring (91) from a wire rod (90), the molding machine (10A) including a measuring device (20A, 20B) according to any one of features 1 to 9 that sequentially measures the compression coil springs (91) that are sequentially molded as workpieces (91) to be measured.

[0075] The dimensions of the compression coil springs which are successively molded by the molding machine of feature 10 can be efficiently measured by a measuring device.

[0076] In addition, although this specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but includes various modifications and variations of the specific examples, as well as parts of the specific examples taken alone. [Explanation of symbols]

[0077] 10A molding machine 20A, 20B Measuring equipment 21 Guide bar 21A Starting end (one end) 21C Termination (other end) 22 Guide pipe 23 Work Guide 24 Camera 29 Backlight 50 Sensors 62A CPU (image processing unit) 90 wire rod 91 Compression coil spring (workpiece) 91M Masterwork R1 molding area R2 front area

Claims

1. A camera for capturing an image of a workpiece manufactured by an industrial machine in the air; An image processing unit that performs image processing of the image of the work captured by the camera to measure the dimensions of the work or the degree of agreement with a master work; A measuring device comprising:

2. The measuring device according to claim 1 , further comprising a work guide that guides the work so as to descend from a molding area in which the work is molded in a molding machine that is the industrial machine, to a position above the area in front of the camera.

3. The workpiece is a compression coil spring, 3. The measurement device according to claim 2, wherein the work guide includes a guide bar having a curved rod shape, one end of which extends horizontally or in a direction inclined relative to the horizontal direction to fit inside the compression coil spring being formed, and the other end of which extends vertically below the one end.

4. 4. The measuring device according to claim 3, wherein the work guide includes a guide pipe having a pipe shape extending vertically and disposed coaxially below the other end of the guide bar.

5. A sensor is provided above the camera to detect the passage of the workpiece, The measuring device according to claim 1 , wherein the camera operates in response to a detection result by the sensor to capture an image of the workpiece.

6. The measurement device according to claim 1 , further comprising a backlight arranged to face the camera from the front.

7. The metrology instrument of claim 1 , wherein the camera comprises a telecentric lens.

8. The camera is provided in plurality and arranged so as to be able to capture images of the workpiece from a plurality of directions; The measuring device according to claim 1 , wherein the image processing unit measures a dimension of the workpiece or a degree of match with a master workpiece based on images simultaneously captured by the multiple cameras.

9. The measuring device according to claim 8 , wherein the image processing unit identifies a three-dimensional model of the workpiece based on images captured simultaneously by the multiple cameras, and measures the dimensions of the workpiece or the degree of match with a master workpiece from the three-dimensional model.

10. A molding machine for sequentially molding a compression coil spring from a wire material, A molding machine comprising the measurement device according to any one of claims 1 to 9, which measures the compression coil springs which are successively formed as workpieces to be measured in sequence.

Images