JP2018036262A - Core wire pitch measurement method, core wire pitch inspection method, and core wire pitch measurement device - Google Patents

Abstract

Kind Code: A1 A pitch of a core wire spirally wound around a mold at the stage of manufacturing a belt can be accurately measured in a short time without relying on manual work. Kind Code: A1 An imaging region is photographed by a camera while irradiating light from an illumination unit to produce a shadow of a core wire within the imaging region. One waveform closest to one end of the image processing region in the pitch direction and the other end of the image processing region in the pitch direction are determined based on the distribution along the pitch direction of the index indicating the brightness of the image processing region set in the captured image. , at both ends in the pitch direction is set as the core wire pitch measurement region. The pitch of the core wire is calculated based on the number of waveforms in the core wire pitch measurement region and the actual length of the core wire pitch measurement region in the pitch direction. [Selection drawing] Fig. 1

Description

  The present invention relates to a core wire pitch measuring method for measuring the pitch of a core wire wound around a mold in a belt manufacturing stage, a core wire pitch inspection method using this measuring method, and a core wire pitch measuring apparatus. .

  In general, a power transmission belt used for power transmission is endless, and is sandwiched in a radial direction between a compression layer on the inner peripheral side, a stretch layer on the outer peripheral side, and the compression layer and the stretch layer. It is comprised by the tension body layer by which the core wire was embed | buried spirally along the direction. In the manufacturing stage of such a transmission belt, the core wire is spirally wound around the mold directly or indirectly by the core wire winding device (see, for example, Patent Document 1). Here, the direction substantially orthogonal to the winding direction of the core wire (that is, the direction that becomes the width direction of the transmission belt) is referred to as a pitch direction.

  The core winding device winds the core around the mold so that the pitch of the core becomes the target value input to the core winding device. However, there is a case where the pitch of the core wire is different from the target value when an operation failure of the core wire winding device occurs. If the pitch of the core wire is different from the target value, the number of core wires in the pitch direction may be different from the target value. Thereby, the tensile strength, elastic modulus, etc. of the belt differ from the target values. Therefore, conventionally, in order to keep the quality of the transmission belt substantially constant, the pitch of the core wound around the mold is measured, and an inspection is performed to determine whether the measurement result is within an allowable value.

  As a method for measuring the pitch of the core wire wound around the mold, a transfer method in which measurement is performed manually is common. In the transfer method, first, tracing paper is applied to the measurement target region where the cores are arranged in the pitch direction, and the convex surface of the core is lightly traced with a writing instrument such as a pencil. As a result, a region corresponding to the convex surface of the core wire is emphasized in black and a transfer image is formed. By visually counting the number of transfer images, the number of core wires arranged in the pitch direction in the measurement target region is counted. Further, the length from the transfer image at one end to the transfer image at the other end in the pitch direction is measured using a ruler. Then, the pitch of the core wire is calculated from the count number of the transferred image and the measured length.

JP 2008-304021 A

However, since the transfer method is a manual operation, even an expert needs about 5 minutes. Further, a twisted cord is used for the core wire, and since the convex surface of the core wire is uneven along the pitch direction, it is difficult to obtain a transfer image that is clear enough to be accurately counted. If even one of the plurality of transfer images to be counted is unclear, it is necessary to redo the transfer operation. Further, in order to ensure measurement accuracy, the number of transfer images to be counted is preferably approximately 50 (standard 30 to 70). However, the pitch of the core wire when a thin core wire is used is, for example, 0.44 mm, and it is difficult to accurately count about 50 transferred images visually, and skill is required.
As described above, in the transfer method, measurement takes time and is not always accurate, so that it is difficult to use it for daily inspection such as process management.
Further, since the transfer method is completely manual, there is a problem that a system for automatically collecting measurement results cannot be constructed.

  Accordingly, in order to solve the above-described problems, the present invention provides a cord pitch that can accurately measure the pitch of the cord wound around the mold in the belt manufacturing stage in a short time without depending on manual work. It is an object of the present invention to provide a measurement method, a core pitch inspection method using the core pitch measurement method, and a core pitch measurement device.

  The core wire pitch measuring method of the present invention is a core wire that measures the pitch in the pitch direction, which is the width direction of the belt, in the core wire wound directly or indirectly around the mold in a spiral manner at the belt manufacturing stage. In the pitch measurement method, the imaging region is photographed while illuminating the imaging region in which the cores are arranged in the pitch direction with an illumination unit to cause shadows of the cores in the imaging region. An image processing step, and an image processing unit sets an image processing region in a captured image captured by the camera, and an image processing region setting step and the image processing unit sets the brightness of the image processing region. A light and dark distribution generation step for generating a distribution of the index to be indicated along the pitch direction, a first reference position that is a peak position larger than a predetermined threshold in the distribution, and a smaller than the predetermined threshold in the distribution; A second reference position that is a bottom position, a position that matches a predetermined threshold in the distribution, and a third reference position that changes to brighten in one direction of the pitch direction across the position; And any one of the fourth reference positions that match the predetermined threshold value in the distribution and change so as to be dark in the one direction of the pitch direction across the position. If the position is a reference position, and the range from the reference position to the adjacent reference position including both the first reference position and the second reference position in the distribution is one waveform, the image processing unit A region having the one waveform closest to one end in the pitch direction of the processing region and the one waveform closest to the other end in the pitch direction of the image processing region at both ends in the pitch direction; Based on the actual length in the pitch direction of the image processing region stored in the setting information storage unit, the core wire pitch measurement region setting step of setting in the core wire pitch measurement region, and the image processing unit The core wire pitch measurement area length calculation step for calculating the actual length of the pitch measurement area in the pitch direction, and the image processing unit counts the number of pitches corresponding to the number of waveforms in the core wire pitch measurement area. And the core wire pitch calculation unit calculates the number of pitches in the core wire pitch measurement region counted in the counting step and the core wire calculated in the core wire pitch measurement region length calculation step. And a pitch calculating step of calculating the pitch of the core wire based on the actual length of the pitch measurement region in the pitch direction.

According to this configuration, since the core wire pitch is measured by processing the image obtained by photographing the core wire wound around the mold, the pitch of the core wire can be reduced in a short time regardless of manual operation. It can be measured.
When photographing with the camera, the illumination unit irradiates light to the photographing region, and a shadow of the core line is generated in the photographing region. Therefore, in the image processing area set in the captured image, the brightness changes periodically in the pitch direction. The period of the distribution along the pitch direction of the index indicating the brightness of the image processing area substantially coincides with the pitch of the core line. In the present invention, this point is used to measure the pitch of the core wire. In the distribution along the pitch direction of the index indicating the brightness of the image processing area, the range from the reference position to the adjacent reference position includes both the peak position larger than the predetermined threshold and the bottom position smaller than the predetermined threshold. In the case of one waveform, the number of core wires in the image processing area can be counted by counting the number of waveforms in the image processing area. The reference position here is a first reference position that is a peak position larger than a predetermined threshold in the distribution, a second reference position that is a bottom position smaller than a predetermined threshold in the distribution, and a predetermined threshold in the distribution. A third reference position that matches the predetermined threshold value in the distribution, and a third reference position that changes so as to brighten in one direction of the pitch direction across the position, and , Any one of the fourth reference positions changing so as to darken in the pitch direction across the position.
However, the actual length in the pitch direction of the image processing region is a preset length and may not be an integral multiple of the pitch of the core wire. Also, the position of the edge in the pitch direction of the image processing area is not uniform, such as being located between the core lines or overlapping the core lines, so the number of pitches in the image processing area is counted incorrectly. There is a risk of doing. For this reason, the pitch of the core wire may not be accurately calculated even if the actual length in the pitch direction in the image processing area is divided by the number of pitches in the image processing area.
Therefore, in the present invention, a region having one waveform closest to one end in the pitch direction of the image processing region and one waveform closest to the other end in the pitch direction of the image processing region is formed on the core pitch. The pitch of the core wire is measured based on the actual length in the pitch direction of the core wire pitch measurement region and the number of pitches (number of waveforms) in the core wire pitch measurement region. Therefore, the pitch of the core wire can be calculated more accurately.
Thus, the present invention can accurately measure the pitch of the core wire wound around the mold in a short time without depending on the manual work.
Since the pitch of the core wire is measured without depending on the manual operation, it is possible to collect actual data such as measurement results and information (photographed image data, etc.) generated in the measurement process. Thereby, when there is a problem in the measurement result, the production lot in which the problem has occurred can be identified and the problem solved based on the collected actual data. Therefore, it is possible to shorten the time required for identifying the production lot where the problem has occurred and for solving the problem.
In the present invention, the phrase “one waveform includes both the first reference position and the second reference position” includes the case where the first reference position or the second reference position exists at the end of one waveform.

  In the core wire pitch measurement method of the present invention, the pitch within a predetermined range is distributed to a plurality of ranks, and the shooting distance and the actual length of the image processing area in the pitch direction are stored in the setting information storage unit for each rank. A setting information storage step for storing, and depending on the rank of a target pitch that is a target value of the pitch of the core wire when the mold is wound around the core wire, the shooting distance and the The distance between the camera and the shooting area is adjusted based on the setting information reading process in which the actual length of the image processing area in the pitch direction is read and the shooting distance read from the setting information storage unit. And a photographing distance adjustment step.

According to this configuration, depending on whether the target pitch, which is the target value of the pitch of the core wire when winding the core wire around the mold, corresponds to which of a plurality of ranks, the actual length in the pitch direction of the imaging distance and the image processing area Therefore, a wide range of pitches can be measured, and high measurement accuracy can be ensured regardless of the size of the pitch.
The setting information storage unit stores the shooting distance and the actual length of the image processing area in the pitch direction for each pitch rank, and does not have to be stored for each pitch, and is therefore stored in the setting information storage unit. The amount of information can be reduced.

  The core pitch measurement method of the present invention preferably further includes a record data collection step of storing the photographed image and the measured pitch of the core line in a record data storage unit.

  According to this configuration, since the photographed image and the measurement result are stored in the actual data storage unit, when there is a problem in the measurement result, based on the data stored in the actual data storage unit, Can identify and solve problems. Therefore, it is possible to shorten the time required for identifying the production lot where the problem has occurred and for solving the problem.

  The core wire pitch inspection method of the present invention determines whether the measured pitch is acceptable or not by comparing the pitch of the core wire measured by the core wire pitch measurement method of the present invention with an allowable value. Process.

  According to this structure, the test of the measurement result of the pitch of the core wire can be performed in a short time.

  The core wire pitch measuring device of the present invention measures the pitch in the pitch direction, which is the width direction of the belt, in the core wire wound directly or indirectly in a spiral shape on the mold at the belt manufacturing stage. A pitch measurement device, wherein a camera that shoots a shooting region in which the cores are arranged in the pitch direction, and the shooting region is irradiated with light when the shooting region is shot by the camera. A setting information storage for storing information used for measuring the pitch of the core wire, and an illuminating unit that causes a shadow of the core wire in the image processing unit, an image processing unit that performs image processing on a captured image captured by the camera And a core wire pitch calculation unit that calculates the pitch of the core wire, wherein the image processing unit (1) sets an image processing area in the captured image, and (2) the image processing area In front of the indicator of light and dark Generating a distribution along the pitch direction; (3) a first reference position that is a peak position larger than a predetermined threshold in the distribution; a second reference position that is a bottom position smaller than a predetermined threshold in the distribution; A third reference position that matches a predetermined threshold in the distribution and changes so as to brighten in one direction of the pitch direction across the position, and matches a predetermined threshold in the distribution And a reference position that is one of the fourth reference positions that change so as to be dark in the one direction of the pitch direction across the position, and in the distribution When the range from the reference position to the adjacent reference position including both the first reference position and the second reference position is a single waveform, the image processing area in the pitch direction An area having the one waveform closest to the end and the one waveform closest to the other end of the image processing area in the pitch direction is set as a core line pitch measurement area (4 ) Based on the actual length in the pitch direction of the image processing region stored in the setting information storage unit, the actual length in the pitch direction of the core wire pitch measurement region is calculated, and (5) the core wire pitch measurement The number of pitches corresponding to the number of the waveforms in the region is counted, and the core pitch calculation unit calculates the number of pitches in the core wire pitch measurement region and the actual length of the core wire pitch measurement region in the pitch direction. Based on the above, the pitch of the core wire is calculated.

According to this configuration, since the core wire pitch is measured by processing the image obtained by photographing the core wire wound around the mold, the pitch of the core wire can be reduced in a short time regardless of manual operation. It can be measured.
When photographing with the camera, the illumination unit irradiates light to the photographing region, and a shadow of the core line is generated in the photographing region. Therefore, in the image processing area set in the captured image, the brightness changes periodically in the pitch direction. The period of the distribution along the pitch direction of the index indicating the brightness of the image processing area substantially coincides with the pitch of the core line. In the present invention, this point is used to measure the pitch of the core wire. In the distribution along the pitch direction of the index indicating the brightness of the image processing area, the range from the reference position to the adjacent reference position includes both the peak position larger than the predetermined threshold and the bottom position smaller than the predetermined threshold. In the case of one waveform, the number of core wires in the image processing area can be counted by counting the number of waveforms in the image processing area. The reference position here is a first reference position that is a peak position larger than a predetermined threshold in the distribution, a second reference position that is a bottom position smaller than a predetermined threshold in the distribution, and a predetermined threshold in the distribution. A third reference position that matches the predetermined threshold value in the distribution, and a third reference position that changes so as to brighten in one direction of the pitch direction across the position, and , Any one of the fourth reference positions changing so as to darken in the pitch direction across the position.
However, the actual length in the pitch direction of the image processing region is a preset length and may not be an integral multiple of the pitch of the core wire. Also, the position of the edge in the pitch direction of the image processing area is not uniform, such as being located between the core lines or overlapping the core lines, so the number of pitches in the image processing area is counted incorrectly. There is a risk of doing. For this reason, the pitch of the core wire may not be accurately calculated even if the actual length in the pitch direction in the image processing area is divided by the number of pitches in the image processing area.
Therefore, in the present invention, a region having one waveform closest to one end in the pitch direction of the image processing region and one waveform closest to the other end in the pitch direction of the image processing region is formed on the core pitch. The pitch of the core wire is measured based on the actual length in the pitch direction of the core wire pitch measurement region and the number of pitches (number of waveforms) in the core wire pitch measurement region. Therefore, the pitch of the core wire can be calculated more accurately.
Thus, the present invention can accurately measure the pitch of the core wire wound around the mold in a short time without depending on the manual work.
Since the pitch of the core wire is measured without depending on the manual operation, it is possible to collect actual data such as measurement results and information (photographed image data, etc.) generated in the measurement process. Thereby, when there is a problem in the measurement result, the production lot in which the problem has occurred can be identified and the problem solved based on the collected actual data. Therefore, it is possible to shorten the time required for identifying the production lot where the problem has occurred and for solving the problem.
In the present invention, the phrase “one waveform includes both the first reference position and the second reference position” includes the case where the first reference position or the second reference position exists at the end of one waveform.

  According to the present invention, the pitch of the core wire wound around the mold in the belt manufacturing stage can be accurately measured in a short time without depending on manual work.

It is a schematic structure figure containing a control block of a core wire pitch measuring device concerning an embodiment of the present invention. It is an II arrow directional view of FIG. It is a schematic diagram which shows an imaging | photography screen. It is a schematic diagram which shows the cross section of the image processing area | region in an imaging | photography screen, the brightness distribution of an image processing area | region, and the core line of an image processing area | region. It is a graph which shows an example of the light-dark distribution of an image processing area. FIG. 4 is a diagram added to the core wire pitch measurement region. It is a structural diagram which shows the specific example of the core wire pitch measuring apparatus of FIG. It is a flowchart which shows the procedure of the core wire pitch measuring method. It is a schematic diagram which shows the additional image processing in 2nd Embodiment. It is a schematic diagram which shows the additional pass / fail determination in 2nd Embodiment. It is a flowchart which shows the procedure of the core wire pitch measuring method in 2nd Embodiment.

  Embodiments of the present invention will be described below. The core wire pitch measuring device 1 of this embodiment is an example of the core wire pitch measuring device of the present invention, and implements an example of the core wire pitch measuring method and the core wire pitch inspection method of the present invention. The core wire pitch measuring apparatus 1 determines the pass / fail of the measured pitch in addition to the measurement of the core wire pitch. That is, the core wire pitch measuring device 1 can be said to be a core wire pitch inspection device.

[1] Measurement Object First, the measurement object of the core wire pitch measurement device 1 of the present embodiment will be described. As shown in FIG. 1, the core wire pitch measuring apparatus 1 measures the pitch of the core wire 100 that is wound directly or indirectly around one cylindrical mold 101 in a spiral manner at the stage of manufacturing the belt. . The case where the core wire 100 is directly wound around the mold 101 is, for example, a case where the core wire is wound around a metal mold with a tooth gap at the manufacturing stage of a polyurethane toothed belt (power transmission belt). The case where the core wire 100 is indirectly wound around the die 101 is, for example, an endless belt set in advance on a die with a tooth gap at the manufacturing stage of a rubber toothed belt (power transmission belt). A core wire may be wound on the molded sleeve. The belt-forming sleeve is a single layered body such as a stretched layer, a compressed layer, a fiber coating layer (for example, canvas) of a transmission belt, or a laminated body in which these are stacked in the thickness direction.

  The mold 101 may be arranged in a direction in which the cylinder axis direction is a vertical direction, or may be arranged in a direction in which the cylinder axis direction is horizontal. Further, the number of molds 101 around which the core wire 100 is wound is not limited to one. Depending on the belt forming method, the core wire 100 may be spirally wound across two molds 101 that are disposed apart in a direction orthogonal to the cylinder axis direction.

  The core wire 100 is wound around the mold 101 by the core wire winding device 102. A target pitch that is a target value of the pitch of the core wire 100 is input to the core wire winding device 102. The core winding device 102 winds the core 100 around the mold 101 so that the pitch of the core 100 becomes a target pitch.

  The direction of the pitch of the core wire 100 wound around the mold 101 is the direction that becomes the width direction of the belt. Hereinafter, the direction that is the width direction of the belt is referred to as a pitch direction. The pitch direction is a direction substantially orthogonal to the winding direction of the core wire 100. At least one winding portion at both ends of the core wire 100 wound around the mold 101 is cut off in a subsequent process and does not constitute a belt. In the portion excluding the both ends, the pitch and winding angle (spiral angle) of the core wire 100 are substantially constant. In FIG. 1 and FIG. 2, the diameter and pitch of the core wire 100 are displayed larger than the actual diameter relative to the diameter of the mold 101 for easy viewing of the drawings. In addition, since the core wire 100 is spirally wound around the mold 101, the actual core wire 100 is slightly inclined with respect to the direction orthogonal to the pitch direction. The core wire 100 is displayed in parallel to the direction orthogonal to the pitch direction.

[2] Core wire pitch measuring device 1
As shown in FIG. 1, the core wire pitch measuring device 1 includes a camera 2, an illumination unit 3, a camera moving mechanism 4, and a control device 10. The control device 10 includes, for example, a storage medium such as a flash memory and a microprocessor. The storage medium includes a setting information storage unit 11 and a performance data storage unit 12. The microprocessor executes information processing based on programs and various data stored in the setting information storage unit 11. The control device 10 includes a setting control unit 13, an image processing unit 14, a core pitch calculation unit 15, and a core wire pitch inspection unit 16 as function processing units.

[2-1] Camera 2
The camera 2 is a digital camera. The camera 2 photographs a part of the core wire 100 wound around the mold 101. The camera 2 captures an area where the cores 100 are arranged in the pitch direction. An area captured by the camera 2 is referred to as an imaging area 103. In FIG. 2, the imaging region 103 is displayed surrounded by a two-dot chain line. When the number of molds 101 around which the core wire 100 is wound is two, the camera 2 is disposed at a position where the core wire 100 on the mold 101 is photographed. The camera 2 takes a picture in response to a command from the control device 10. Further, the control value (focus value or the like) of the camera 2 can be controlled by the control device 10. The camera 2 may have an autofocus function that automatically adjusts the focus value.

  FIG. 3 shows a photographed image 20 obtained by photographing the photographing region 103 with the camera 2. Data of the captured image 20 captured by the camera 2 is transmitted to the control device 10 and input to the image processing unit 14 of the control device 10. The image processing unit 14 sets a rectangular image processing area 21 in the captured image 20. In FIG. 3, the image processing area 21 is displayed surrounded by a one-dot chain line. In addition, in the shooting area 103 in FIG. 2, an area corresponding to the image processing area 21 is displayed surrounded by an alternate long and short dash line. The image processing area 21 is an area where image processing is performed in order to measure the pitch of the core wire 100. The four sides of the image processing area 21 are set inside the four sides of the captured image 20.

  In the present specification, the number of cores 100 arranged in the pitch direction in an arbitrary region is defined as the number of cores arranged. The shooting distance L (see FIG. 1), which is the distance between the camera 2 and the shooting area 103, is set so that the number of core lines in the image processing area 21 is approximately 50 (standard 30 to 70). Is done. Thereby, the measurement accuracy of the pitch can be ensured. In order to ensure the measurement accuracy, it is necessary to secure the length of the image processing area 21 in the pitch direction to some extent. On the other hand, the length of the image processing region 21 in the direction orthogonal to the pitch direction may be shorter than the length of the image processing region 21 in the pitch direction. Since the winding angle (spiral angle) of the core wire 100 is substantially constant, and the core wires 100 in the captured image 20 are arranged substantially in parallel, the length in the direction orthogonal to the pitch direction of the image processing region 21 is short. Also, the measurement accuracy can be ensured.

  As long as the measurement resolution of the camera 2 is not changed, the number of pixels in the pitch direction of the image processing area 21 may be constant regardless of the shooting distance L. Note that the number of pixels in the pitch direction of the image processing area 21 may be changed according to the shooting distance L or the like. Further, the number of pixels in the direction orthogonal to the pitch direction of the image processing area 21 may be constant.

[2-2] Lighting unit 3
The light source of the illumination unit 3 is, for example, an LED light source. The lighting device 3 is turned on and off by the control device 10. The illumination unit 3 irradiates the imaging region 103 with light so as to cause a shadow of the core 100 in the imaging region 103. More specifically, the illumination unit 3 irradiates the imaging region 103 with light so as to cause shadows of all the core lines 100 in the image processing region 21. That is, the illumination unit 3 is arranged at a position away from the area corresponding to the image processing area 21 in the imaging area 103 in the pitch direction. In addition, the illumination unit 3 is arranged so that light from the illumination unit 3 is incident on the imaging region 103 obliquely when viewed in a direction orthogonal to both the imaging direction and the pitch direction. An incident angle α (see FIG. 1) of light with respect to the imaging region 103 is, for example, 70 °. The illumination unit 3 may be arranged at a fixed position with respect to the imaging region 103 regardless of the imaging distance L and the pitch of the core 100. Note that the position of the illumination unit 3 relative to the imaging region 103 may be changed according to the imaging distance L.

  The illumination unit 3 causes the shadow of the core 100 in the imaging region 103 to generate a difference (contrast) between a bright portion and a dark portion in the imaging region 103. Dark portions (shadows) occur between the adjacent cores 100 (that is, on the mold 101 or the belt forming sleeve) and on the core 100. A bright part occurs on the core 100. Depending on the incident angle α and the pitch of light, a bright portion may be generated between adjacent core wires 100 in addition to the core wire 100.

  As shown in FIG. 2, the width in the direction orthogonal to the pitch direction of the light source of the illumination unit 3 is sufficiently wider than the actual length in the direction orthogonal to the pitch direction of the image processing region 21. Thereby, since a substantially parallel light beam can be irradiated over the entire region in the direction orthogonal to the pitch direction of the image processing region 21, unevenness or unevenness of illuminance or the like in the direction orthogonal to the pitch direction in the image processing region 21 can be prevented. When the actual length in the direction orthogonal to the pitch direction of the image processing area 21 is, for example, 4 mm, the width in the direction orthogonal to the pitch direction of the light source of the illumination unit 3 is, for example, 100 mm.

[2-3] Camera moving mechanism 4
The camera moving mechanism 4 is configured to be able to move the camera 2 in the shooting direction. That is, the shooting distance L between the camera 2 and the shooting area 103 can be adjusted by the camera moving mechanism 4. Instead of moving the camera 2 in the shooting direction, the shooting distance L may be adjusted by moving the mold 101 in the shooting direction. The operation of the camera moving mechanism 4 is controlled by the control device 10. The camera moving mechanism 4 can also be manually operated.

[2-4] Control device 10
As described above, the control device 10 includes the setting information storage unit 11 and the result data storage unit 12. In addition, the control device 10 includes a setting control unit 13, an image processing unit 14, a core pitch calculation unit 15, and a core wire pitch inspection unit 16 as function processing units. The control device 10 may be configured by a single device, or may be configured by a plurality of devices that are arranged at physically separated positions and are electrically connected. Data of the captured image 20 is transmitted from the camera 2 to the control device 10. The control device 10 is connected to the core winding device 102, and a target pitch is transmitted from the core winding device 102 to the control device 10.

[2-4-1] Setting information storage unit 11
The setting information storage unit 11 stores information used for measuring the pitch of the core wire 100. The setting information storage unit 11 stores information for specifying the size and position of the image processing area 21 in the captured image 20. Specifically, for example, the number of pixels between each of the four sides of the captured image 20 and each of the four sides of the image processing area 21 is stored.
In addition, the setting information storage unit 11 stores the control value (focus value, etc.) of the camera 2, the shooting distance, and the actual length in the pitch direction of the image processing area 21 in association with the target pitch. More specifically, the setting information storage unit 11 distributes and stores a predetermined range of pitches into a plurality of ranks, and for each rank, the control value (focus value, etc.) of the camera 2, the shooting distance, and the image The actual length of the processing area 21 in the pitch direction is stored. These pieces of information stored for each rank in the setting information storage unit 11 are information obtained by photographing a plurality of samples with different pitches of the core wire 100 with the camera 2 and actually measuring them.
The setting information storage unit 11 stores an arithmetic expression and a program used for calculating the pitch of the image processing core 100.

[2-4-2] Setting Control Unit 13
The setting control unit 13 controls the camera moving mechanism 4 and the camera 2. The setting control unit 13 determines which of the plurality of ranks the target pitch corresponds to. The setting control unit 13 reads out the shooting distance according to the rank from the setting information storage unit 11 and sets the camera moving mechanism 4 so that the shooting distance L between the camera 2 and the shooting target becomes the read shooting distance. Control. Further, the setting control unit 13 reads the control value (focus value, etc.) of the camera 2 corresponding to the rank of the target pitch from the setting information storage unit 11 so that the read control value (focus value, etc.) of the camera 2 is obtained. The camera 2 is controlled.

[2-4-3] Image processing unit 14
The image processing unit 14 processes the captured image 20 captured by the camera 2. The image processing unit 14 sets the image processing area 21 in the captured image 20 based on the information read from the setting information storage unit 11. The image processing unit 14 generates a distribution along the pitch direction of the index indicating the brightness of the image processing area 21. Hereinafter, this distribution is referred to as a light-dark distribution. The index indicating brightness is, for example, contrast or brightness. In FIG. 4, a graph schematically showing an example of the contrast distribution of the contrast index is displayed. FIG. 5 is a graph showing an example of a light / dark distribution of an actual contrast index. The contrast index is obtained by indexing the contrast indicating the difference in brightness between images in the range of −100 to +100. The closer to +100, the higher the percentage of bright parts, and the closer to -100, the higher the percentage of dark parts. In addition to the light / dark distribution, FIG. 4 shows a cross-sectional view of the image processing region 21 and the core wire 100 in the image processing region 21.

The light / dark distribution is generated as follows, for example.
An index indicating brightness is assigned to each pixel in the image processing area 21. The sum of the indexes indicating the brightness of one pixel column along the direction orthogonal to the pitch direction is divided by the number of pixels in this pixel column to calculate the average value of the indexes indicating the brightness of this pixel column. This calculation process is performed for all the pixel columns in the image processing area 21. This average value distribution is a light-dark distribution. Note that, instead of calculating the average value, the distribution of the sum of the indexes indicating the brightness of each pixel column along the direction orthogonal to the pitch direction may be the brightness distribution. Due to the light / dark distribution, the image processing region 21 can be regarded as one pixel column along the pitch direction.

  A peak position larger than a predetermined threshold in the light / dark distribution is set as a first reference position. In the light / dark distribution of FIG. 4, the two positions P <b> 1 are first reference positions closest to both ends of the light / dark distribution in the pitch direction. The contrast index serving as a threshold value for specifying the position P1 is, for example, +25.

  A bottom position smaller than a predetermined threshold in the light / dark distribution is set as a second reference position. In the light / dark distribution of FIG. 4, the two positions P <b> 2 are second reference positions closest to both ends of the light / dark distribution in the pitch direction. The contrast index serving as a threshold for specifying the position P2 is, for example, −25. The threshold value for specifying the second reference position is not the same as the threshold value for specifying the first reference position, and is darker than that.

  A position that coincides with a predetermined threshold in the brightness distribution and that changes so as to brighten in one direction in the pitch direction across the position is defined as a third reference position. In the light / dark distribution of FIG. 4, the two positions P3a are an example of a third reference position closest to both ends of the light / dark distribution in the pitch direction. In the light / dark distribution of FIG. 4, the two positions P3b are other examples of the third reference position closest to both ends of the light / dark distribution in the pitch direction. The contrast index at the position P3a is +25, and the contrast index at the position P3b is −25. In a region straddling the positions P3a and P3b, the contrast index increases (ie, becomes brighter) as the position is farther from the illumination unit 3. That is, here, the direction away from the light source (the direction from the left to the right of the page) corresponds to the above-mentioned “one direction of the pitch direction”.

  A position that coincides with a predetermined threshold in the light / dark distribution and that changes across the position so as to be dark in the one direction of the pitch direction is defined as a fourth reference position. In the light / dark distribution of FIG. 4, the two positions P4a are an example of a fourth reference position closest to both ends of the light / dark distribution in the pitch direction. In the light / dark distribution of FIG. 4, the two positions P4b are other examples of the fourth reference position closest to both ends of the light / dark distribution in the pitch direction. The contrast index at the position P4a is +25, and the contrast index at the position P4b is −25. In a region straddling the positions P4a and P4b, the contrast index is smaller (ie, darker) as the position is farther from the illumination unit 3.

  Any one of the first to fourth reference positions is set as a reference position. There are a plurality of reference positions in the brightness distribution. That is, there are a plurality of reference positions in the image processing area 21. Further, in the light-dark distribution, the range from the reference position to the adjacent reference position including both the first reference position and the second reference position is one waveform. The image processing unit 14 detects one waveform closest to one end of the image processing region 21 in the pitch direction and one waveform closest to the other end of the image processing region 21 in the pitch direction. The image processing unit 14 includes an area having one waveform closest to one end in the pitch direction of the image processing area 21 and one waveform closest to the other end in the pitch direction of the image processing area 21 at both ends in the pitch direction. To the core wire pitch measurement area 22. The threshold value for specifying the reference position is stored in the setting information storage unit 11, and the image processing unit 14 sets the core wire pitch measurement region 22 based on the threshold value read from the setting information storage unit 11. The core wire pitch measurement region 22 is a region where the pitch of the core wire 100 is measured. In FIG. 6, the core pitch measurement region 22 when the position P4a (fourth reference position) is set as the reference position is indicated by hatching with hatching.

  The image processing unit 14 counts the number of waveforms in the core wire pitch measurement region 22 (that is, the number of waveforms in the light / dark distribution). The number of waveforms in the core wire pitch measurement region 22 can be regarded as the number of pitches of the core wire 100 in the core wire pitch measurement region 22. The image processing unit 14 counts the number of waveforms in the core wire pitch measurement region 22 as the number of pitches.

Note that which of the first to fourth reference positions is set as the reference position may be determined according to, for example, the pitch range to be measured or the incident angle α of light from the illumination unit 3.
Regardless of which of the first to fourth reference positions is set as the reference position, the ease of execution of the arithmetic processing of the image processing unit 14 is substantially the same.

Depending on the distance in the pitch direction from the illuminating unit 3, the incident angle α of the light is slightly different. Therefore, depending on the distance in the pitch direction from the illuminating unit 3, the brightest position on the core wire 100 and the way the shadow appears are slightly different. Therefore, even if the reference position is any of the first to fourth reference positions, the shortest distance in the pitch direction between the reference position close to the illumination unit 3 and the center of the core 100, and the reference position away from the illumination unit 3 The shortest distance in the pitch direction from the center of the core 100 may be different. As the incident angle α increases, the shortest distance in the pitch direction between the reference position close to the illumination unit 3 and the center of the core 100 and the shortest distance in the pitch direction between the reference position far from the illumination unit 3 and the center of the core 100. The difference between and tends to increase. In addition, when the pitch of the core wire 100 varies, the shortest distance in the pitch direction between the reference position and the center of the core wire 100 may vary.
However, the difference in the shortest distance in the pitch direction between the reference position at both ends in the pitch direction of the image processing region 21 and the center of the core 100 is so small that it can be ignored. Therefore, the pitch measurement accuracy is substantially the same regardless of any of the first to fourth reference positions.

  In some cases, foreign matter such as fiber scraps or dust coming out of the core wire 100 may adhere on or between the core wires 100. However, the size of such foreign matters is significantly smaller than that of the core wire 100. Therefore, even if such a foreign substance is interposed between the core lines, the second reference position having a bottom value smaller than the predetermined threshold appears in the light / dark distribution, so that measurement accuracy can be ensured.

  The image processing unit 14 reads the actual length of the image processing area 21 in the pitch direction from the setting information storage unit 11 according to the rank of the target pitch. The image processing unit 14 calculates the actual length of the core pitch measurement region 22 in the pitch direction based on the read actual length of the image processing region 21 in the pitch direction.

[2-4-4] Core wire pitch calculation unit 15
The core wire pitch calculation unit 15 counts the number of pitches (number of waveforms) in the core wire pitch measurement region 22 counted by the image processing unit 14 and the actual pitch direction of the core wire pitch measurement region 22 calculated by the image processing unit 14. Based on the length, the pitch of the core wire 100 in the core wire pitch measurement region 22 is calculated. Specifically, the core wire 100 in the core wire pitch measurement region 22 is obtained by dividing the actual length in the pitch direction of the core wire pitch measurement region 22 by the number of pitches (number of waveforms) in the core wire pitch measurement region 22. Is calculated.

[2-4-5] Core wire pitch inspection unit 16
The core wire pitch inspection unit 16 determines whether the pitch of the core wire 100 calculated by the core wire pitch calculation unit 15 is acceptable. The core wire pitch inspection unit 16 determines the pass / fail of the pitch by comparing the calculated pitch of the core wire 100 with an allowable value. When the calculated pitch of the core wire 100 is within the allowable value, it is determined to be acceptable, and when it is not within the allowable value, it is determined to be unacceptable.
The allowable value is a target pitch ± tolerance. When the target pitch is, for example, 0.4 to 1.5 mm, the tolerance is, for example, about 0.02 mm. The tolerance may be constant or may be changed according to the pitch or rank. When the tolerance is changed according to the pitch or rank, the setting information storage unit 11 stores the tolerance in association with the pitch or rank.

  The result of the pass / fail determination by the core pitch inspection unit 16 is displayed on a monitor (not shown). Thereby, the worker can know the result of the pass / fail determination. The monitor may be included in the control device 10 or may be connected to the control device 10. The monitor may also display the pitch of the core 100 calculated by the core pitch calculator 15. Further, the monitor may display information obtained by image processing such as a control value (focus value or the like) of the camera 2, a captured image 20, an image processing area 21, a core pitch measurement area 22, a light / dark distribution. . Note that the pitch measurement result, the pass / fail determination result, and the like may be output to an output device other than the monitor.

[2-4-6] Performance data storage unit 12
The record data storage unit 12 records the photographed image 20 data, data generated in the course of image processing (brightness distribution, etc.), the measured pitch of the core wire 100, and the pass / fail judgment result of the measured pitch. Store the data.

[3] Specific Example of Core Wire Pitch Measuring Device 1 Next, a core wire pitch measuring device 1 ′ shown in FIG. 7 as a more specific example of the core wire pitch measuring device 1 of the embodiment shown in FIG. 1 will be described. . 7 has all the configurations of the core wire pitch measuring device 1 of FIG. Hereinafter, a specific configuration of the core wire pitch measuring device 1 ′ will be described. The core wire pitch measuring device 1 ′ includes a frame 5 and an illumination unit moving mechanism 6.

  The illumination unit 3 is attached to the illumination unit moving mechanism 6. A camera 2 and an illumination unit moving mechanism 6 are attached to the frame 5. The frame 5 is installed on the camera moving mechanism 4 and can be linearly moved in the shooting direction of the camera 2 by the camera moving mechanism 4. When the core wire 100 is wound around the mold 101, the frame 5 is arranged at a standby position indicated by a two-dot chain line in FIG.

  The camera moving mechanism 4 is a rodless cylinder, for example. The rodless cylinder is configured to be able to move a slide block mounted on the rail in a linear direction along the rail by air or the like.

  The illumination unit moving mechanism 6 is an electric cylinder, for example, and has an extendable rod 6a. The illumination unit 3 is fixed to the tip of the rod 6 a of the illumination unit moving mechanism 6 via a support arm 7. A stopper 8 is provided at the tip of the rod 6a. The length of the rod 6 a of the illumination unit moving mechanism 6 is set so that the stopper 8 comes into contact with the mold 101. Thereby, the illumination unit 3 is positioned at a fixed position with respect to the imaging region 103.

  The setting information storage unit 11 stores the protruding amount of the rod 6a of the illumination unit moving mechanism 6 for each rank of the pitch of the core wire 100. Table 1 shows an example of a part of information stored in the setting information storage unit 11 of the core wire pitch measuring device 1 ′.

[4] Core Wire Pitch Measurement Method / Core Wire Pitch Inspection Method Next, a core wire pitch measurement method and a core wire pitch inspection method using the core wire pitch measurement device 1 (1 ′) will be described.
First, as preparation, information necessary for pitch measurement is acquired and stored in the setting information storage unit 11 (setting information storage step). Specifically, a plurality of samples in which the core wire 100 is wound around the mold 101 at different pitches are prepared. Then, the camera movement mechanism 4 is manually operated to adjust the shooting distance so that the number of core lines in the image processing area 21 is approximately 50 (standard 30 to 70), and shooting is repeated. The pitch to be measured is distributed to a plurality of ranks, and the shooting distance is determined for each rank. Further, the control value (focus value or the like) of the camera 2 is determined for each rank (that is, for each shooting distance). In the case of the core pitch measuring device 1 ′ in FIG. 7, the projection distance of the rod 6 a of the illumination unit moving mechanism 6 is also determined by determining the shooting distance. Further, the actual length of the image processing area 21 in the pitch direction is measured for each rank (that is, for each shooting distance). Specifically, a ruler is placed in the shooting area 103 and the scale of the ruler is read on the shooting screen. The information acquired in this way is stored in the setting information storage unit 11.

  From here, the procedure for measuring the pitch of the core wire 100 and the procedure for inspecting the measured pitch will be described with reference to the flowchart of FIG. The core wire pitch measuring apparatus 1 performs the process of FIG. 8 every time the measurement object is changed.

  When the winding operation of the core wire 100 by the core wire winding device 102 is completed, a signal indicating the start of the core wire pitch measurement operation and a signal indicating the target pitch are transmitted from the core wire winding device 102 to the control device 10 (steps). S1: Target pitch input step). The setting control unit 13 of the control device 10 determines which rank of the plurality of ranks the target pitch corresponds to (step S2: rank determination step).

  The setting control unit 13 of the control device 10 reads the shooting distance and the control value (focus value, etc.) of the camera 2 according to the corresponding rank from the setting information storage unit 11 (step S3: setting information reading step). In the case of the core wire pitch measuring device 1 ′ in FIG. 7, the setting control unit 13 also reads out the protruding amount of the rod 6 a of the illumination unit moving mechanism 6 according to the corresponding rank from the setting information storage unit 11.

  The setting control unit 13 controls the camera moving mechanism 4 so that the shooting distance L between the camera 2 and the shooting area 103 becomes the read shooting distance (step S4: shooting distance adjustment step). In the case of the core pitch measuring device 1 ′ in FIG. 7, the setting control unit 13 controls the illumination unit moving mechanism 6 so that the protrusion amount of the rod 6 a of the illumination unit moving mechanism 6 becomes the read protrusion amount. Further, the setting control unit 13 adjusts the control value of the camera 2 so as to be the read control value (focus value or the like) of the camera 2 (step S5: camera control value adjustment step). Moreover, the setting control part 13 lights the illumination part 3 (step S6: irradiation process). When the core winding device 102 winds the core 100 around the mold 101, the illumination unit 3 is turned off. The direction of the illumination unit 3 is adjusted in advance. The order in which steps S4 to S6 are performed is not particularly limited.

  Next, the camera 2 that has received the imaging command from the setting control unit 13 images the core wire 100 wound around the mold 101 (step S7: imaging process). Data of the captured image 20 is sent from the camera 2 to the control device 10. The control device 10 may display the captured image 20 on the monitor.

When the captured image 20 is input to the image processing unit 14, the image processing unit 14 reads out information for specifying the size and position of the image processing area 21 stored in the setting information storage unit 11, and the captured image 20. The image processing area 21 is set inside (step S8: image processing area setting step).
The image processing unit 14 generates a light / dark distribution along the pitch direction of the index indicating the light / dark of the image processing area 21. This light / dark distribution may also be displayed on the monitor (step S9: light / dark distribution generating step).

The image processing unit 14 detects one waveform closest to one end in the pitch direction of the image processing area 21 in the image processing area 21.
For this purpose, first, the image processing unit 14 detects a reference position closest to one end of the image processing area 21 in the pitch direction in the image processing area 21. For example, when the peak position (first reference position) larger than a predetermined threshold is the reference position, the image processing unit 14 detects the peak position closest to one end in the pitch direction of the image processing region 21, and this peak position is If it exceeds the threshold, it is set as a reference position. If the peak position does not exceed the threshold value, the peak position next to one end in the pitch direction is detected and compared with the threshold value. Accordingly, it is possible to prevent a peak position generated by irradiating light to a foreign substance such as dust from being detected as a reference position.
Next, the image processing unit 14 detects a reference position adjacent to the other end side of the reference position closest to one end. Thereafter, the image processing unit 14 determines whether the peak position and the bottom position are detected between the reference position closest to one end and the reference position adjacent to the other end. When the peak position and the bottom position are detected, the image processing unit 14 determines whether the peak position is larger than a predetermined threshold and whether the bottom position is smaller than the predetermined threshold. Do. When the peak position is larger than the predetermined threshold and the bottom position is smaller than the predetermined threshold, the image processing unit 14 sets the range from the reference position closest to one end to the adjacent reference position as one waveform. To detect.

  In the same procedure, the image processing unit 14 detects one waveform closest to the other end in the pitch direction of the image processing area 21 in the image processing area 21. The image processing unit 14 includes an area having one waveform closest to one end in the pitch direction of the image processing area 21 and one waveform closest to the other end in the pitch direction of the image processing area 21 at both ends in the pitch direction. Then, it is set in the core wire pitch measurement region 22 (step S10: core wire pitch measurement region setting step).

  Further, the image processing unit 14 reads the actual length in the pitch direction of the image processing area 21 corresponding to the corresponding rank from the setting information storage unit 11 (step S11: setting information reading step). The image processing unit 14 calculates the actual length in the pitch direction of the core wire pitch measurement region 22 based on the read actual length in the pitch direction of the image processing region 21 (step S12: core wire pitch measurement region length calculation step) ).

  The image processing unit 14 detects all the reference positions in the light / dark distribution, and the number of waveforms in the core pitch measurement region 22 in the case where one waveform is formed from the reference position to the adjacent reference position as the number of pitches. Counting (step S13: counting process).

  The core wire pitch calculation unit 15 includes the number of pitches (number of waveforms) in the core wire pitch measurement region 22 counted by the image processing unit 14 and the pitch direction of the core wire pitch measurement region 22 calculated by the image processing unit 14. Based on the actual length, the pitch of the core wire 100 is calculated (step S14: pitch calculation step). The calculated pitch is displayed on the monitor.

  The core wire pitch inspection unit 16 determines whether the pitch is acceptable or not by comparing the calculated pitch with an allowable value (target pitch ± tolerance) (step S15: inspection process). The result of the pass / fail judgment is displayed on the monitor.

  Recorded data 20, data generated in the course of image processing (light / dark distribution, etc.), calculated pitch of the core 100, and result data such as the result of pass / fail judgment are stored in the result data storage unit 12 ( Step S16: Actual data collection step).

When the pass determination is made, the control device 10 turns off the illumination unit 3 and controls the camera moving mechanism 4 to move the camera 2 to the standby position. In addition, the control device 10 transmits a signal indicating that the operation is continued to the core winding device 102.
On the other hand, when the failure is determined, the control device 10 transmits an operation stop signal to the core winding device 102. Further, the control device 10 may transmit an operation stop signal to a device that performs the next process of the winding process of the core wire 100. Thereby, it is possible to reliably prevent the core pitch defective product from proceeding to the next step. The “apparatus for performing the next step” corresponds to, for example, a sleeve winding apparatus. When the belt to be manufactured is, for example, a rubber toothed belt, the sleeve winding device winds and laminates the remaining sleeve member (rubber layer or the like) on the core wire to complete the belt forming sleeve.

According to the configuration of the present embodiment, by processing the captured image 20 acquired by capturing the core wire 100 wound around the mold 101, the pitch of the core wire 100 is measured. The pitch of the core wire 100 can be measured in a short time.
When shooting with the camera 2, the illumination unit 3 irradiates light to the shooting region 103, and a shadow of the core 100 is generated in the shooting region 103. Therefore, in the image processing region 21 set in the captured image 20, the brightness changes periodically in the pitch direction. The period of the distribution along the pitch direction of the index indicating the light and darkness of the image processing area 21 substantially coincides with the pitch of the core wire 100. In the distribution along the pitch direction of the index indicating the light and darkness of the image processing area 21, when one waveform is formed from the reference position to the adjacent reference position, the number of waveforms in the image processing area 21 is counted, thereby performing image processing. The number of core wires 100 (number of pitches) arranged in the pitch direction in the region 21 can be counted. The reference position here is a first reference position that is a peak position larger than a predetermined threshold in the distribution, a second reference position that is a bottom position smaller than a predetermined threshold in the distribution, and a predetermined threshold in the distribution. A third reference position that matches the predetermined threshold value in the distribution, and a third reference position that changes so as to brighten in one direction of the pitch direction across the position, and , Any one of the fourth reference positions changing so as to darken in the pitch direction across the position.
However, the actual length of the image processing area 21 in the pitch direction may be a preset length and may not be an integral multiple of the pitch of the core wire 100. In addition, since the position of the end in the pitch direction of the image processing area 21 is not uniform, such as being located between the core lines or overlapping the core lines, the number of pitches in the image processing area 21 is incorrect. There is a risk of counting. Therefore, even if the actual length in the pitch direction in the image processing area 21 is divided by the number of pitches in the image processing area 21, the pitch of the core wire 100 may not be accurately calculated.
Therefore, in the present embodiment, an area having one waveform closest to one end in the pitch direction of the image processing area 21 and one waveform closest to the other end in the pitch direction of the image processing area 21 at both ends in the pitch direction, The pitch of the core wire 100 is set based on the actual length in the pitch direction of the core wire pitch measurement region 22 and the number of waveforms (number of pitches) in the core wire pitch measurement region 22. Is measuring. Therefore, the pitch of the core wire 100 can be calculated more accurately.
Thus, in this embodiment, the pitch of the core wire 100 wound around the mold 101 can be accurately measured in a short time without depending on manual work.
Since the pitch of the core wire 100 is measured without depending on the manual work, it is possible to collect actual data such as measurement results and information generated during the measurement process (data of the photographed image 20 and the like). Thereby, when there is a problem in the measurement result, the production lot in which the problem has occurred can be identified and the problem solved based on the collected actual data. Therefore, it is possible to shorten the time required for identifying the production lot where the problem has occurred and for solving the problem.

In the present embodiment, a predetermined range of pitches is assigned to a plurality of ranks, and the shooting distance and the actual length in the pitch direction of the image processing area 21 are stored in the setting information storage unit 11 for each rank. Then, according to the rank of the target pitch, which is the target value of the pitch of the core wire 100 when the mold 101 is wound around the core wire 100, the shooting distance and the actual length of the image processing region 21 in the pitch direction are set from the setting information storage unit 11. , And the distance between the camera 2 and the shooting area 103 is adjusted so that the read shooting distance is obtained.
In this way, depending on which of the plurality of ranks the target pitch corresponds to, the shooting distance and the actual length in the pitch direction of the image processing area 21 are changed, so that a wide range of pitches can be measured, High measurement accuracy can be ensured regardless of the size of the pitch.
The setting information storage unit 11 stores the shooting distance and the actual length of the image processing area in the pitch direction for each pitch rank, and does not have to be stored for each pitch. The amount of information to be reduced can be reduced.

  In the present embodiment, the captured image 20 and the measured pitch of the core wire 100 are stored in the record data storage unit 12. According to this configuration, when there is a problem in the measurement result, the production lot in which the problem has occurred can be identified and the problem solved based on the data stored in the record data storage unit 12. Therefore, it is possible to shorten the time required for identifying the production lot where the problem has occurred and for solving the problem.

  Moreover, in this embodiment, the pass / fail of the measured pitch is determined by comparing the pitch of the core wire 100 measured by the core wire pitch measurement method with an allowable value. According to this structure, the test of the measurement result of the pitch of the core wire 100 can be performed in a short time.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

In the above-described embodiment, the number of pitches is counted by counting the number of waveforms in the core wire pitch measurement region 22. However, if the number of pitches corresponding to the number of waveforms can be counted, the counting method is different from this. It may be. That is, in the present invention, “counting the number of pitches corresponding to the number of waveforms in the core pitch measurement region” is not limited to counting the number of pitches by counting the number of waveforms.
For example, when the reference position used to specify both ends in the pitch direction of the core wire pitch measurement region 22 is not the first reference position (peak position), the distance from the first reference position to the adjacent first reference position is 1 As the waveform, the number of ends in the pitch direction of the waveform in the core pitch measurement region 22 may be counted as the number of pitches.
Further, for example, when the reference position used to specify both ends of the pitch direction of the core wire pitch measurement region 22 is not the first reference position (peak position), the first reference position in the core wire pitch measurement region 22 May be counted as the number of pitches.
Further, for example, when the reference position used to specify both ends of the core wire pitch measurement region 22 in the pitch direction is the first reference position (peak position), the first reference position in the core wire pitch measurement region 22 A value obtained by subtracting 1 from the number may be counted as the number of pitches.

  In the above-described embodiment, the pitch of the core line of one shooting area 103 is calculated using only one camera 2, but a plurality of shooting areas 103 are simultaneously shot by a plurality of cameras 2 and obtained. The pitch of the core lines of the plurality of imaging regions 103 may be calculated from the plurality of captured images 20 obtained.

  The core wire pitch measurement devices 1 and 1 ′ of the above-described embodiment change the shooting distance L according to the rank of the target pitch, but the shooting distance L may be constant regardless of the target pitch. However, in this case, it is preferable that the pitch range of the measurement target of the core wire pitch measuring devices 1 and 1 ′ is narrower than the above-described embodiment (for example, a range corresponding to one rank).

[Second Embodiment]
In the above-described embodiment (hereinafter referred to as the first embodiment), in order to ensure the measurement accuracy of the calculated core wire pitch (measured value), the core wires in the image processing region 21 are arranged for each rank of the pitch. The actual length in the pitch direction of the image processing area is provided so that the number is approximately 50 (standard 30 to 70) (this case is set to 1). In addition to the measurement based on this setting 1, for example, the actual length in the pitch direction of the image processing area is separately set so that the number of core lines in the image processing area is 2 (the number of pitches is 1) for each rank of the pitch. It may be set to be extremely shorter than setting 1 (this case is set to 2). In this case, determination may be made by comparing the calculated core wire pitch (measured value) with a new reference (allowable value) separately provided.

Next, an outline of image processing according to setting 2 will be described with reference to FIGS. 1 and 9 to 11.
First, the setting information storage unit 11 in FIG. 1 specifies information for specifying the size and position of the image processing area 121 corresponding to setting 2 in addition to the information for specifying the size and position of the image processing area 21 corresponding to setting 1. Is remembered. Further, the core wire pitch inspection unit 16 in FIG. 1 compares with the allowable value 1 corresponding to the setting 1 and determines pass / fail, and also compares with the allowable value 2 corresponding to the setting 2 and determines pass / fail. .

FIG. 9 shows an image processing area 121 corresponding to setting 2 set in a photographed image obtained by photographing with a camera. The image processing area 121 is displayed surrounded by a one-dot chain line in FIG.
Further, FIG. 9 shows a case where there is a periodic disturbance of the core wire pitch such that an excessive pitch portion and an excessive pitch portion appear alternately. The image processing area 121 is set so that two cores can enter even if there is such a disturbance.
The generation of the light / dark distribution is the same as that described in the first embodiment. In the example of FIG. 9, the core wire pitch measurement region 122 set with the first reference position as a reference is indicated by hatching. From this core wire pitch measurement region 122, one pitch corresponding to one waveform can be calculated.
Note that periodic disturbance is detected not only when the number of core lines in the image processing area is 2 (the number of pitches is 1) but also when the number is 4 (the number of pitches is 3). it can.

 As a result, as shown in FIG. 10, for example, a core wire pitch disturbance such that an excessive pitch portion and an excessive pitch portion appear alternately due to an operation failure of the core wire winding device (2 to 2 cores). In the measurement according to setting 1, the measurement value of the core wire pitch is leveled and falls within the allowable value (target pitch ± tolerance), so the pass / fail judgment is passed, as described above. Unable to detect a disturbed core pitch. However, according to the measurement by setting 2, since the actual length in the pitch direction of the image processing region is set to be extremely shorter than setting 1, the measured value of the core wire pitch is less than the allowable value (FIG. 10B). ) Or an excessive value (FIG. 10 (c)), and rejecting the pass / fail judgment based on a new standard (allowable value) separately provided, it is possible to detect the disturbance of the core wire pitch as described above. is there.

 As a result, the core winding device or the like can be immediately inspected and adjusted to improve the core winding state to a state in which there is almost no disturbance in the core pitch (the state in FIG. 10A, the same as FIG. 4). It becomes possible. In other words, preferably, by using the measurement according to setting 1 and the measurement according to setting 2 in combination (for example, continuous measurement of both), the pitch of the core wire wound around the mold in the belt manufacturing stage can be set regardless of manual operation. In addition to being able to measure accurately in a short time, it is possible to quickly cope with the improvement of the winding condition of the core wire.

Further, the measurement procedure will be described with reference to the flowchart of FIG. A difference from the flowchart of FIG. 8 is that an image processing area setting step (step 8) for setting an image processing area in a captured image can set setting 2 in addition to setting 1. Although the setting 1 is the flow described with reference to FIG. 8, the setting 2 is continuously executed as an additional flow (steps S109 to S115). In the illustrated example, the additional flows are used in parallel, but may be used in series.
In the additional flow, as setting 2, when the number of core lines in the image processing area is 2 (the number of pitches is 1), the count in step S113 is 1, and in step S114, it is divided by 1. The pitch will be calculated.

  As described above, in addition to setting 1 for setting a long image processing region in which average pitch accuracy can be detected, a short image in which disturbances in the core line pitch in which an excessive pitch portion and an excessive pitch portion appear alternately can be detected. By providing the setting 2 for setting the processing area, it is possible to measure with high accuracy.

That is, in the cord pitch measurement method of the present invention, the image processing region setting step includes an excessive pitch portion and an excessive pitch in addition to setting 1 for setting a long image processing region in which average pitch accuracy can be detected. It is preferable to provide a setting 2 for setting a short image processing region in which a disturbance in the core line pitch in which portions appear alternately can be detected, and to perform continuous processing.
In the cord pitch measuring device according to the present invention, the image processing unit sets a long image processing region in which an average pitch accuracy can be detected, and includes an excessive pitch portion and an excessive pitch portion. What sets the short image processing area | region which can detect disorder of the core wire pitch which appears alternately is preferable.

  A test was conducted to verify the effect of the present invention. The core wire pitch measurement method and the core wire pitch inspection method of the embodiment of the present invention, and the core wire pitch measurement method and the core wire pitch inspection method (comparative example) by the transfer method of the prior art are applied to the mold at the belt manufacturing stage. The time required for measurement and inspection of the pitch of the wound core wire was compared and evaluated, and the measured values of the pitch were compared. Moreover, in order to evaluate the measured value of the pitch measured by the Example and the comparative example, the pitch of the core wire wound around the metal mold | die was directly measured as a reference example. Specifically, a measuring tool such as a ruler or a caliper was applied to the surface where the core wires were arranged in the pitch direction, and the pitch was measured. The core wire pitch measurement method and the core wire pitch inspection method of the example are the same as those in the first embodiment. Since both the comparative example and the reference example are completely manual work, they were performed by skilled workers.

  Using the same measurement object in the order of Example, Comparative Example, and Reference Example, the pitch of the core wire was measured and inspected. The object to be measured was such that a core wire was wound at a target pitch of 0.52 mm on a tooth cloth set in a die with a tooth gap at the stage of manufacturing a rubber toothed belt having a circumference of 564 mm. The cord used was a cord in which glass fiber filament groups were twisted together and immersed in an RFL liquid as an adhesive and a protective agent composed of a rubber compound. The diameter of the core wire was 0.5 mm. The allowable value used for the pass / fail judgment was 0.52 mm (target pitch) ± 0.02 mm.

  In the comparative example, the core pitch was measured and inspected completely manually. Specifically, a transfer method expert counted the number of transferred images and performed measurement using a ruler, and then calculated the pitch of the core using a calculator. Immediately after the calculation, pass / fail judgment was performed. In pass / fail judgment, the measurer compares the display value on the calculator's LCD screen with the tolerance value used for pass / fail judgment printed on the test paper at hand, and the tester himself marks the pass / fail judgment result on the test paper at hand. (Circled on pass / fail prints).

In the examples and comparative examples, the time required for measuring the pitch was measured. In the embodiment, the time required for the pitch measurement is that the pitch calculated by the core pitch calculation unit from the time when the control device receives a signal indicating the start of the core pitch measurement operation is displayed on the monitor. The time until the time was taken. In the comparative example, the time required to measure the pitch is measured from the time when the core winding around the mold is completed and the worker starts moving from the standby position (a point 1 m away from the core winding device). The time until the result was displayed on the calculator's LCD screen was used.
In the examples and comparative examples, the time required for the pitch measurement and inspection was measured. In the examples, the end time of the time required for the measurement and inspection of the pitch is the time when the result of the pass / fail determination by the core wire pitch determination unit is displayed on the monitor. In the comparative example, the end time of the time required for the pitch measurement and inspection is the time when the measurer himself / herself has finished marking the pass / fail judgment result on the inspection sheet at hand.

The test results are shown in Table 2. In the case of the example, the breakdown of the time required for the pitch measurement took about 1 second until step S4 in the flowchart of FIG. 8, and about 1 second thereafter.
Further, in the embodiment, the time taken for the pass / fail judgment of the measured value of the pitch is instantaneous (within an estimated 0.1 seconds), so the time required for the pitch measurement, the time required for the pitch measurement and inspection, However, no difference in perception was found.

  As can be seen from Table 2, the time required for the pitch measurement was significantly shorter in the example using the image processing system than in the comparative example by hand. The measured values of the examples and comparative examples were not found to cause a problem as compared with the measured values of the reference example that is assumed to be truly accurate. Since the number of tests is one, the measurement accuracy cannot be mentioned, but the measured values of the examples are closer to the measured values of the reference example than the measured values of the comparative example, indicating that the accuracy is high. .

DESCRIPTION OF SYMBOLS 1, 1 'Core wire pitch measuring apparatus 2 Camera 3 Illumination part 4 Camera moving mechanism 10 Control apparatus 11 Setting information storage part 12 Result data storage part 13 Setting control part 14 Image processing part 15 Core wire pitch calculation part 16 Core wire pitch test | inspection Section 20 Photographed image 21 Image processing area 22 Core pitch measurement area 100 Core wire 101 Mold 102 Core winding device 103 Imaging area

Claims (5)

A core wire pitch measuring method for measuring a pitch in a pitch direction which is a width direction of the belt in a core wire spirally wound directly or indirectly around a mold at a manufacturing stage of the belt,
A photographing step of photographing the photographing region with a camera while irradiating the photographing region in which the cores are arranged in the pitch direction with an illumination unit to cause shadows of the core in the photographing region; ,
An image processing area setting step in which an image processing section sets an image processing area in a captured image captured by the camera;
A light / dark distribution generation step in which the image processing unit generates a distribution along the pitch direction of an index indicating light and darkness of the image processing region;
A first reference position that is a peak position larger than a predetermined threshold in the distribution, a second reference position that is a bottom position smaller than the predetermined threshold in the distribution, and a position that matches the predetermined threshold in the distribution, In addition, the third reference position that changes so as to brighten in one direction of the pitch direction across the position, and a position that matches a predetermined threshold in the distribution, and straddles the position. One of the fourth reference positions changing so as to be dark in the one direction of the pitch direction is set as a reference position,
When the range from the reference position to the adjacent reference position including both the first reference position and the second reference position in the distribution is one waveform,
The image processing unit has the one waveform closest to one end of the image processing region in the pitch direction and the one waveform closest to the other end of the image processing region in the pitch direction at both ends of the pitch direction. A core wire pitch measurement region setting step for setting the region having the core wire pitch measurement region;
Core image pitch measurement, wherein the image processing unit calculates the actual length of the core wire pitch measurement region in the pitch direction based on the actual length of the image processing region stored in the setting information storage unit. An area length calculation step;
The image processing unit counts the number of pitches corresponding to the number of the waveforms in the core wire pitch measurement region;
The core wire pitch calculation unit calculates the number of pitches in the core wire pitch measurement region counted in the counting step and the pitch of the core wire pitch measurement region calculated in the core wire pitch measurement region length calculation step. And a pitch calculation step of calculating the pitch of the core based on the actual length of the direction. A setting information storage step of allocating the pitch in a predetermined range to a plurality of ranks, and storing the shooting distance and the actual length of the image processing area in the pitch direction in the setting information storage unit for each rank;
In accordance with the rank of the target pitch, which is the target value of the pitch of the core wire when the mold is wound around the core wire, the shooting distance and the actual pitch direction of the image processing area from the setting information storage unit. A setting information reading process in which the length is read;
The photographing distance adjustment step of adjusting a distance between the camera and the photographing region based on the photographing distance read from the setting information storage unit. Core wire pitch measurement method.   The core wire pitch measuring method according to claim 1, further comprising a result data collecting step of storing the photographed image and the measured pitch of the core wire in a result data storage unit. .   An inspection step of determining pass / fail of the measured pitch by comparing the pitch of the core wire measured by the core wire pitch measuring method according to claim 1 with an allowable value. A core wire pitch inspection method comprising: A core wire pitch measuring device for measuring a pitch in a pitch direction which is a width direction of the belt in a core wire spirally wound directly or indirectly around a mold in a manufacturing stage of the belt,
A camera that captures an imaging region in which the cores are aligned in the pitch direction;
An illumination unit that irradiates light to the imaging unit to cause a shadow of a core wire in the imaging region when imaging the imaging region by the camera;
An image processing unit that performs image processing on a captured image captured by the camera;
A setting information storage unit for storing information used for measuring the pitch of the core wire;
A core wire pitch calculation unit that calculates the pitch of the core wire,
The image processing unit
(1) An image processing area is set in the captured image,
(2) generating a distribution along the pitch direction of an index indicating the brightness of the image processing area;
(3) A first reference position that is a peak position that is larger than a predetermined threshold in the distribution, a second reference position that is a bottom position that is smaller than the predetermined threshold in the distribution, and a position that matches the predetermined threshold in the distribution. A third reference position that changes across the position so as to become brighter in one direction of the pitch direction, and a position that matches a predetermined threshold in the distribution, and this position A fourth reference position that changes so as to darken in the one direction of the pitch direction across the base, and any one position as a reference position,
When the range from the reference position to the adjacent reference position including both the first reference position and the second reference position in the distribution is one waveform,
An area having the one waveform closest to one end in the pitch direction of the image processing area and the one waveform closest to the other end in the pitch direction of the image processing area at both ends in the pitch direction; Set the pitch measurement area
(4) Based on the actual length in the pitch direction of the image processing region stored in the setting information storage unit, the actual length in the pitch direction of the core wire pitch measurement region is calculated,
(5) Count the number of pitches corresponding to the number of waveforms in the core pitch measurement region,
The core pitch calculation unit
A core wire pitch measuring device that calculates the pitch of the core wire based on the number of pitches in the core wire pitch measuring region and the actual length of the core wire pitch measuring region in the pitch direction. .

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