bar cutting device

Abstract

To provide a bar cutting device capable of preventing the outflow of products with defective cut lengths by detecting the occurrence of irregular cut lengths before cutting when cutting a plurality of bars. [Solution] In a bar cutting device 10, which performs a positioning process to determine the cutting length L of a predetermined number N of bars BL by bringing the tips of the bars BL into contact with a positioning stopper 20 and then simultaneously cuts the bars BL with a cutting machine 16, an image sensor 78 is provided above the position where the positioning stopper 20 and the tips of the bars BL come into contact, and an unevenness determination ECK is performed to determine whether or not there is unevenness in the tip positions of the bars BL from an image GZ captured by the image sensor 78 at the end of the positioning process PC. As a result, when cutting multiple bars, uneven cut lengths are detected before cutting, preventing the outflow of products with incorrect cut lengths.

Description

[Technical Field]

[0001] The present invention relates to a bar cutting device that conveys a predetermined number of aligned parallel bars in the longitudinal direction and cuts them simultaneously. [Background technology]

[0002] When cutting long bars, such as threaded steel bars for reinforced concrete, to desired lengths repeatedly and continuously using a cutting machine, it is necessary to ensure dimensional accuracy in the cuts. To address this issue, a cutting device is known that stops the tip of the bar being transported on a conveying path against a positioning stopper (butting device), and by positioning the tip, determines the length of the bar before cutting it. An example of such a device is the rebar cutting device described in Patent Document 1. Patent Document 1 discloses technology related to drive control of the conveying path when stopping the bar against the positioning stopper (butting device). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-74730 Summary of the Invention [Problem to be solved by the invention]

[0004] In bar cutting machines that use a conveyor for transport and simultaneously cut multiple parallel bars transported on the conveyor, there is a problem with the positioning stopper positioning the ends of multiple bars, resulting in misalignment of the ends of the bars. For example, the outer surface of threaded steel bars has a bamboo-knot-like or screw-like ridge and valley shape. When multiple bars are held together, if adjacent bars are close together, the ridges and valleys of the knots will interlock, causing misalignment of the ends. Furthermore, slippage between the conveyor and the bars can cause some bars to not reach the positioning stopper, resulting in misalignment of the ends. Cutting when the ends are not aligned results in discrepancies in the cut lengths of the bars. For example, if cut products are piled up in a storage container, it is difficult to completely determine the quality of the cut length by manual inspection or a ruler, leading to the issue of products with incorrect cut lengths being produced.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a bar cutting device that can detect any uneven cutting lengths before cutting when cutting multiple bars, thereby preventing the output of products with incorrect cutting lengths. [Means for solving the problem]

[0006] That is, the gist of the first invention is a system including: (a) an upstream carry-in conveyor and a downstream carry-out conveyor that convey a predetermined number of bars in a parallel state aligned adjacent to each other in a longitudinal direction; a cutter that is provided between the carry-in conveyor and the carry-out conveyor and cuts the bars simultaneously; and a positioning stopper that is provided on a conveying surface of the carry-out conveyor so as to be movable relative to the conveying surface, and that abuts against the tip of the bar being conveyed downstream and restricts the movement of the bar in the downstream direction; A bar cutting device that conveys material from the upstream side to the downstream side through the cutting machine, and performs a positioning process to determine the cutting length of the bar by abutting the tip of the bar against the positioning stopper, and then cuts the bar with the cutting machine, (b) is provided with an image sensor that takes an image of the periphery of the tip of the bar above the position where the positioning stopper abuts against the tip of the bar, and performs an irregularity judgment to judge whether or not there is irregularity in the tip position of the bar from the image taken by the image sensor at the end of the positioning process. (c) the determination of misalignment is performed by detecting each end face of the bar from the photographed image by image processing, and determining that there is no misalignment at the tip end of the bar if the number of detected end faces, which is the number of detected end faces present in a predetermined area in the photographed image, is equal to the value of the predetermined number, and determining that there is misalignment at the tip end of the bar if it is smaller than the value of the predetermined number. The reason is that.

[0007] The gist of the second invention is that in the first invention, the positioning stopper is movable longitudinally on the conveying surface and movable to an upper position that is a predetermined height or more above the lower position where it abuts against the tip of the bar, and when moved to the upper position, the positioning stopper does not interfere with the shooting area of ​​the image sensor.

[0009] No. 3 The gist of the invention is 1 or 2 In the invention, if it is determined through the misalignment determination that there is no misalignment at the tip position of the bar material, cutting is performed by the cutting machine, and if it is determined that there is misalignment at the tip position of the bar material, a retry process is performed in which the bar material is transported a predetermined distance upstream and then the positioning process is performed again.

[0010] No. 4 The gist of the invention is 3In the invention, the bar cutting device is provided with a notification means for notifying when an abnormality occurs, and when the number of times the retry process is repeated reaches a predetermined number of times, the notification means notifies the user of the occurrence of an abnormality and the device automatically stops. [Effects of the Invention]

[0011] According to the bar cutting device of the first invention, an image sensor is provided above the contact position between the positioning stopper and the end of the bar to capture an image of the periphery of the end of the bar, and an image captured by the image sensor at the end of the positioning process is used to determine whether or not there is any unevenness in the end position of the bar. As a result, when cutting multiple bar stock, any unevenness in the cut length is detected before cutting, preventing the outflow of products with incorrect cut lengths. The misalignment determination is performed by detecting each end face of the bar material from the photographed image by image processing, and determining that there is no misalignment at the tip end of the bar material if the number of detected end faces, which is the number of detected end faces present in a predetermined area in the photographed image, is equal to the predetermined number, and determining that there is misalignment at the tip end of the bar material if it is smaller than the predetermined number. This allows the misalignment determination to be performed appropriately.

[0012] According to the second aspect of the bar cutting device, the positioning stopper is movable longitudinally on the conveying surface and to an upper position that is at least a predetermined height above the lower position where it contacts the tip of the bar. When the positioning stopper is moved to the upper position, it does not interfere with the image sensor's imaging area. This allows the misalignment determination to be performed appropriately when the positioning stopper is moved to the upper position and does not interfere with the image sensor's imaging area. Furthermore, by moving the positioning stopper longitudinally, the cut length of the bar can be changed to a desired length. Furthermore, by moving the positioning stopper to the upper position after cutting the bar, the cut bar product can be easily discharged by the discharge conveyor.

[0014] No. 3According to the bar cutting device of the present invention, if it is determined that there is no misalignment in the tip positions of the bar stock as a result of the misalignment determination, the bar stock is cut by the cutting machine, but if it is determined that there is misalignment in the tip positions of the bar stock, a retry process is performed in which the bar stock is transported a predetermined distance upstream and then the positioning process is performed again. This prevents the outflow of products with an incorrect cut length and allows the bar cutting device to continue operating without stopping even if there is misalignment in the tip positions of the bar stock.

[0015] No. 4 According to the bar cutting device of the present invention, the bar cutting device is provided with a means for notifying when an abnormality occurs, and when the number of retry processes reaches a predetermined number, the notifying means notifies of the occurrence of an abnormality and automatically stops the device. This prevents the outflow of products with defective cut lengths, and also properly stops the device when recovery is not possible through the retry process. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating a schematic configuration of a bar cutting device according to an embodiment of the present invention; [Figure 2] 2 is a diagram showing an example of a bar to be cut by the bar cutting device of FIG. 1. FIG. [Figure 3] FIG. 2 is a front view illustrating an example of the cutting machine of FIG. [Figure 4] 2 is a side view illustrating an example of the positioning device (positioning stopper) of FIG. 1. FIG. [Figure 5] 10A and 10B are diagrams illustrating an example of determination content in misalignment determination. [Figure 6] 2 is a flowchart illustrating a main part of the control operation of the electronic control device of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described in detail below with reference to the drawings. Note that in the following embodiment, the drawings are appropriately simplified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0018] Fig. 1 is a diagram illustrating the schematic configuration of a bar cutting device 10 according to one embodiment of the present invention, which simultaneously cuts a predetermined number N of bars BL (N=4 in this embodiment). The upper diagram in Fig. 1 is a plan view of the bar cutting device 10 as seen from vertically above, with the x-axis representing the conveying direction of the bar BL, the z-axis representing the vertical direction, and the y-axis representing the direction perpendicular to the x-axis (conveying direction) in the plane. The bar BL is conveyed from the upstream direction on the left side of the drawing to the downstream direction on the right side of the drawing.

[0019] 1, a bar cutting device 10 includes an input conveyor 12, an output conveyor 14, a cutting machine 16, and a positioning device 18. The positioning device 18 includes a positioning stopper 20 and a side frame 22.

[0020] The carry-in conveyor 12 is a so-called roller conveyor that conveys a predetermined number N (=4) of bars BL in the longitudinal direction, i.e., the conveying direction shown in Fig. 1, and is driven by a drive unit 30. Similarly, the carry-out conveyor 14 is a so-called belt conveyor that conveys the bars BL in the conveying direction, and is driven by a drive unit 32. The drive units 30 and 32 are controlled by an electronic control unit 80, which will be described later.

[0021] A predetermined number N (=4) of bars BL are supplied onto the carry-in conveyor 12 by a supply device (not shown) in a parallel state, with the x-axis direction as the longitudinal direction and the bars aligned adjacent to each other in the y-axis direction. The bars BL supplied onto the carry-in conveyor 12 are transported from the upstream carry-in conveyor 12 through a cutting machine 16 to a downstream discharge conveyor 14. In FIG. 1 , the cutting position of the cutting machine 16 for the bars BL is indicated by a cutting line ZL. A positioning stopper 20 is provided on the conveying surface 14a of the discharge conveyor 14, located downstream from the cutting line ZL by a cutting length L, so as to be movable relative to the conveying surface 14a. The leading end of the bar BL transported downstream abuts against the positioning stopper 20, restricting the bar BL from moving downstream, thereby determining the cutting length L of the bar BL.

[0022] FIG. 2 is a diagram showing an example of a bar BL to be cut by the bar cutting device 10. The bar BL has a length of, for example, 5 to 6 m and an average diameter of, for example, 10 mm (D10) to 19 mm (D19). The deformed bar, as shown in FIG. 2(a), does not have longitudinal ribs but has spiral nodes 42 formed circumferentially at regular intervals along the longitudinal direction and flat surfaces 44 formed by removing portions of the nodes 42 along the circumferential direction. This deformed bar has an oval cross section consisting of a pair of parallel sides and a pair of arcs connecting the pair of sides. The bar BL in FIGS. 1 and 3 to 5 is assumed to be the one shown in FIG. 2(a). However, other shapes of deformed bars may also be used, such as those without flat surfaces 44 and having longitudinal ribs 46, as shown in FIG. 2(b).

[0023] FIG. 3 is a diagram illustrating an example of the cutting machine 16, and is a front view of the cutting machine 16 as viewed from the downstream side of the x-axis in FIG. 1. The cutting machine 16 is disposed between the loading conveyor 12 and the unloading conveyor 14 and simultaneously cuts a predetermined number N (=4) of bars BL passed through the cutting machine 16. In FIG. 3, the cutting machine 16 includes a circular saw drive device 52 rotatably mounted on a base 50 about a horizontal first axis C1. The circular saw drive device 52 includes a rotating frame (not shown) rotatably mounted about the first axis C1, an electric motor (not shown) fixed to the rotating frame, a disk-shaped circular saw 54 supported by the rotating frame rotatably about a second axis C2 parallel to the first axis C1 and driven to rotate by the electric motor, and an electric actuator (not shown) mounted on the base 50 and configured to rotate the rotating frame (not shown) about the first axis C1 and repeatedly reciprocate the circular saw 54 to the position shown in FIG. 3. The position of the rotation plane of the circular saw 54, that is, the cutting plane, corresponds to the position of the cutting line ZL in FIG.

[0024] The circular saw 54 is covered by an openable cover 58 having a notch 56 for avoiding interference with a bar material, such as a bar material BL described below.

[0025] A clamping device 60 is provided on the base 50 to clamp and secure a predetermined number N (=4) of bars BL into which the circular saw 54 of the circular saw driving device 52 will cut. The clamping device 60 includes a horizontal vise 62 that clamps the portion of the bar BL near the portion to be cut by the circular saw 54 from the lateral direction, i.e., horizontally, and a vertical vise 64 that clamps the portion of the bar BL near the portion to be cut by the circular saw 54 from the vertical direction.

[0026] The vertical vise 64 is fixed in position and has a horizontal support surface FS that supports a predetermined number N (=4) of bar materials BL. The vertical vise 64 has a work table 64a that functions as a vertical fixed claw of the vertical vise 64, a vertical movable claw 64b that is arranged so that it can move towards and away from the work table 64a, and a vertical vise hydraulic cylinder 64c that drives the vertical movable claw 64b towards the work table 64a to clamp the bar material BL from the vertical direction.

[0027] The horizontal vise 62 has a backing plate 62a fixed to the work table 64a on the side of the circular saw drive unit 52, laterally movable claws 62b provided so as to be able to approach and move away from the backing plate 62a, and a horizontal vise hydraulic cylinder 62c that drives the laterally movable claws 62b toward the backing plate 62a to clamp the bar BL from the side. A groove 62d is formed in the laterally movable claws 62b to receive the circular saw 54 in order to avoid interference with the circular saw 54 during cutting operation.

[0028] The cutting machine 16 includes a switching valve that controls the horizontal vice hydraulic cylinder 62c and the vertical vice hydraulic cylinder 64c, and is equipped with a hydraulic control circuit 66 that controls the operation of the horizontal vice 62 and the vertical vice 64 of the clamping device 60. The operation of the horizontal vice hydraulic cylinder 62c and the vertical vice hydraulic cylinder 64c is controlled by an electronic control device 80, which will be described later.

[0029] Fig. 4 is a diagram illustrating an example of the positioning device 18, and is a side view of the positioning device 18 as viewed from below in the y-axis direction in Fig. 1. Fig. 4 shows a state in which the bar BL and the positioning stopper 20 are in contact with each other.

[0030] The positioning device 18 includes the side frames 22 and a moving unit 70. The positioning stopper 20 is included in the moving unit 70.

[0031] The side frame 22 is a frame-like frame that supports the moving unit 70 (positioning stopper 20) so that it can move in the x-axis direction (conveying direction) on the conveying surface 14a of the discharge conveyor 14, and is provided in the x-axis direction (conveying direction) next to and parallel to the discharge conveyor 14, as shown in Fig. 1. The moving unit 70 is attached to guide rails 22a and 22b provided on the wall surface of the side frame 22 in the x-axis direction so that it can move along the side frame 22 in the x-axis direction (conveying direction).

[0032] The moving unit 70 includes a drive mechanism 72, a stopper mechanism 74, a detection mechanism 76, and an image sensor 78. The drive mechanism 72, the stopper mechanism 74, the detection mechanism 76, and the image sensor 78 are controlled by an electronic control device 80, which will be described later.

[0033] The drive mechanism 72 moves the moving unit 70 in the x-axis direction (conveying direction). Rotational power from the servo motor 72a is transmitted to a gear 72e via a pulley 72b, a belt 72c, and a pulley 72d. The gear 72e, like the guide rails 22a and 22b, engages with a rack 22c provided on the wall surface of the side frame 22 in the x-axis direction, thereby moving the moving unit 70 along the side frame 22 in the x-axis direction (conveying direction). By controlling the drive mechanism 72, the position of the moving unit 70 (positioning stopper 20) on the conveying surface 14a is specified, thereby determining the cutting length L. In addition, cables connected for controlling and driving the drive mechanism 72, stopper mechanism 74, detection mechanism 76, image sensor 78, etc. are arranged so that their connections are maintained as the moving unit 70 moves by a cable sliding mechanism (not shown).

[0034] The stopper mechanism 74 has two parallel stopper yokes 74a connected to a rotating shaft 74b and a connecting shaft 74c in a ladder-like configuration, and the rotating shaft is disposed in the moving unit 70 so as to be rotatable about an axis C3. The connecting shaft 74c is also connected to an actuator arm 74e extending from an actuator 74d. As shown in the bubble in Figure 4, the positioning stopper 20 connects the two stopper yokes 74a on the opposite side of the connecting shaft 74c and is disposed in a direction that abuts against the bar BL. The bubble in Figure 4 shows the positioning stopper 20 as viewed from the upstream side. In Fig. 4, the positioning stopper 20 is in a position LP (hereinafter referred to as the lower position) where it abuts against the bar BL, but when the actuator arm 74e is extended by the actuator 74d, the stopper yoke 74a rotates about the axis C3, and the positioning stopper 20 can be moved to a position UP (hereinafter referred to as the upper position) that is above the lower position LP by a predetermined height h or more. In Fig. 4, the upper position UP is indicated by a two-dot chain line.

[0035] The detection mechanism 76 detects the approach of the bar BL to the positioning stopper 20 by detecting the deflection of the detection plate 76a caused by the bar BL being conveyed pushing against it with a laser sensor 76c. The detection plate 76a is made of an elastic material, such as a rubber plate, and returns to a non-deflected state, i.e., a straight state in the z-axis direction (vertical direction), when the bar BL is not present. The detection of the approach of the bar BL is used to control the stopping of the bar BL. The conveyance is stopped at a predetermined timing, such as after a predetermined time has elapsed or after a predetermined distance has been conveyed, which is suitable for aligning the leading ends of the bar BL. In FIG. 4, similar to the stopper mechanism 74, the detection plate 76a is at a lower position LP where it is deflected by the bar BL. However, the actuator 76b can be operated to move the detection plate 76a to an upper position UP, which is above the lower position LP by a predetermined height h or more. In FIG. 4, the upper position UP is indicated by a two-dot chain line, similar to the stopper mechanism 74.

[0036] The image sensor 78 is disposed above the contact position between the positioning stopper 20 and the tip of the bar BL, and photographs the area around the tip of the bar BL. In FIG. 4, the image sensor 78 photographs from an obliquely upward direction downstream of the contact position at a photographing angle θ. The photographing angle θ is set in advance to a suitable value through design or experimentation. The image sensor 78 is disposed so that the stopper mechanism 74 does not interfere with the photographing area of ​​the image sensor 78 even when the positioning stopper 20 moves to the upper position UP. For example, a clearance is ensured between the stopper suspender 74a and the image sensor 78 so as not to interfere with the photographing area of ​​the image sensor 78 in the y-axis direction, and a clearance is ensured between the positioning stopper 20 and the image sensor 78 so as not to interfere with the photographing area of ​​the image sensor 78 in the x-axis direction.

[0037] Preferably, the stopper mechanism 74 and the detection mechanism 76 are moved to the upper position UP except during execution of a positioning process PC, which will be described later, for positioning the bar BL. The predetermined height h for movement to the upper position is preset to a suitable value that does not interfere with the various operations of the discharge conveyor 14. This allows the cut bars BL to be easily removed, for example, by transporting them downstream on the discharge conveyor 14 or tilting the discharge conveyor 14 in the y-axis direction to remove them from a stocker or the like provided adjacent to the discharge conveyor.

[0038] 1, the bar cutting device 10 is equipped with an electronic control device 80 that controls the operation of the bar cutting device 10. The electronic control device 80 is made up of a so-called microcomputer, and controls the operation of the drive device 30 that drives the carry-in conveyor 12, the drive device 32 that drives the carry-out conveyor 14, the cutter 16, and the positioning device 18 (movement unit 70) by exchanging control signals with each of them via control interfaces CIF (CIF1, CIF2, CIF3, CIF4).

[0039] The bar cutting machine 10 also includes a notification device 34 that displays or notifies the operating status of the machine, and the notification device 34 functions as a notification means when an abnormality occurs, for example, by communicating with the electronic control device 80 via the control interface CIF5. The notification device 34 corresponds to the "notification means" of the present invention.

[0040] The electronic control device 80 functionally includes a cutting control unit 82 that controls the cutting of the bar material BL, and the cutting control unit 82 functionally includes a positioning control unit 84, a cutting machine control unit 86, an irregularity determination unit 88, etc.

[0041] The positioning control unit 84 performs a positioning process PC. The positioning process PC is performed, for example, in the following procedure. First, the moving unit 70 is moved to a position corresponding to the set cutting length L, and then the positioning stopper 20 and the detection plate 76a are moved to the lower position LP. Next, the carry-in conveyor 12 and the carry-out conveyor 14 are driven to transport the bar BL downstream. Then, once the detection mechanism 76 detects the approach of the bar BL, the drive of the carry-in conveyor 12 and the carry-out conveyor 14 is stopped under a preset stopping condition to stop the transport, and the positioning stopper 20 and the detection plate 76a are moved to the upper position UP.

[0042] The cutting machine control unit 86 operates the vertical vise hydraulic cylinder 64c and the horizontal vise hydraulic cylinder 62c of the vertical vise 64 to perform a cutting process CC in which a predetermined number N (=4) of bar material BL is held by the clamp device 60 and the circular saw 54 is moved back and forth to cut the bar material BL.

[0043] In a conventional bar cutting device, cutting process CC was performed after positioning process PC. However, in the positioning process PC, there was a problem that the tip positions of the bar BLs did not align. For example, the outer peripheral surface of a bar BL such as a threaded bar steel has a bamboo joint shape or a threaded mountain-valley shape. When applying a plurality of materials, if adjacent materials are close to each other, misalignment occurs due to the meshing of the mountains and valleys of the joints, and the tip positions do not align. Also, there were cases where bars that did not reach the positioning stopper due to conveyance slippage between the conveyor and the bar occurred, resulting in a situation where the tip positions did not align. Therefore, in the bar cutting device 10 of the present embodiment, after the positioning process PC, an alignment failure determination ECK is performed by the alignment failure determination unit 88.

[0044] The alignment failure determination unit 88 performs an alignment failure determination ECK to determine whether there is an alignment failure at the tip position of the bar BL from the captured image GZ of the image sensor 78 at the end of the positioning process PC shown in FIG. 5, for example. The alignment failure determination ECK is performed, for example, by detecting each end face BF of the bar BL from the captured image GZ by image processing, and when the number of aligned ends BCT, which is the number of detected end faces BF existing within a predetermined region GN in the captured image GZ, is equal to the value of the predetermined number N (BCT = N = 4), it is determined that there is no alignment failure at the tip position of the bar BL, and when it is smaller than the value of the predetermined number N (BCT < N = 4), it is determined that there is an alignment failure at the tip position of the bar BL. Thereby, the alignment failure determination ECK is appropriately performed.

[0045] FIG. 5 illustrates an example of the determination process performed by the misalignment determination ECK. FIG. 5(a) shows an example of a case where there is no misalignment at the tip of the bar BL, and FIG. 5(b) shows an example of a case where there is misalignment at the tip of the bar BL. In FIGS. 5(a) and 5(b), the detected end faces BF are indicated by diagonal lines. In FIG. 5(a), all of the end faces BF are located within the predetermined region GN (dashed line) in the captured image GZ (solid line). The number of end faces BCT is 4, indicating that there is no misalignment at the tip of the bar BL. In FIG. 5(b), one end face BF extends beyond the predetermined region GN (dashed line). The number of end faces BCT is 3, indicating that there is misalignment at the tip of the bar BL. The predetermined region GN is determined in advance by design or experimentation to be a suitable range that allows determination of whether or not there is misalignment at the tip of the bar BL. For example, the size of the predetermined area GN in the vertical direction (x-axis direction) on the paper is set based on the height of the end face BF and the allowable range of variation, and the size of the predetermined area GN in the horizontal direction (y-axis direction) on the paper is set based on the guide width of the carry-out conveyor 14. Also, in Fig. 5, the predetermined area GN is set as a rectangular range, but it is not limited to a rectangle and may be set as a range of any suitable shape.

[0046] In the misalignment determination ECK, for example, setting data for image detection is switched depending on the type of bar BL. Also, for example, learning processing for image detection may be performed using AI learning or the like.

[0047] FIG. 6 is a flowchart illustrating the main control operations of the cutting control section 82 corresponding to the functions of the electronic control device 80, which are executed during the cutting operation of the bar BL.

[0048] First, in step (hereinafter, step will be omitted) S10, it is determined whether or not the bar material BL to be cut has been supplied to the carry-in conveyor 12. If this determination is negative, the determination in S10 is repeated.

[0049] If the determination in S10 is positive, a positioning process PC is performed in S20, which corresponds to the function of the positioning control unit 84, and then a misalignment determination ECK is performed in S30, which corresponds to the function of the misalignment determination unit 88. The misalignment determination ECK detects the occurrence of a cut length misalignment before cutting, thereby preventing products with defective cut lengths from being shipped out.

[0050] Next, in S40, the result of the misalignment determination ECK, i.e., whether or not there is misalignment at the tip end position of the bar BL, is determined. If the determination in S40 is negative, i.e., if there is no misalignment at the tip end position of the bar BL, in S50, the number of repetitions of the retry process RTC (hereinafter referred to as the retry count) RCT, which will be described later, is cleared (RCT=0), and cutting process CC is performed in S60, which corresponds to the function of the cutting machine control unit 86.

[0051] Next, in S70, a cut bar discharge process is performed in which the cut bars BL are discharged from the discharge conveyor 14, and then in S80, it is determined whether or not cutting has been completed for all of the bars BL supplied to the carry-in conveyor 12. If the determination in S80 is negative, the process proceeds to S20, and the processes from S20 onwards are repeated. If the determination in S80 is positive, this routine is terminated.

[0052] If the determination in S40 is positive, that is, if there is a misalignment in the tip position of the bar BL, the retry count RCT is incremented (RCT=RCT+1) in S90, and then it is determined in S100 whether the retry count RCT is equal to or greater than a predetermined number of times NGCT (RCT≧NGCT).

[0053] If the determination in S100 is negative, in S110, the carry-in conveyor 12 and the carry-out conveyor 14 are driven to transport the bar BL upstream a predetermined distance BD, and the process proceeds to S20, where a retry process RTC is performed to perform the positioning process PC again. In Fig. 6, the retry process RTC is indicated by a dashed line frame. This prevents products with an incorrect cut length from being output, and allows the bar cutting device 10 to continue operating without stopping even if the leading ends of the bar BL are not aligned. The predetermined distance BD is determined and set by design or experimentation as a value that allows the leading ends of the bar BL to be aligned appropriately in the retry process RTC.

[0054] If the determination in S100 is negative, i.e., if the retry count RCT is equal to or greater than the predetermined number of times NGCT (RCT≧NGCT), the notification device 34 is notified of the abnormality in S120, the bar cutting device 10 is automatically stopped, and this routine is terminated. This prevents the outflow of products with an incorrect cut length and properly performs the stopping process when recovery is not possible by the retry process RTC. The predetermined number of times NGCT is set to a suitable value determined by design or experiment.

[0055] As described above, the bar cutting device 10 of this embodiment is provided with the image sensor 78 for photographing the periphery of the tip of the bar BL above the contact position between the positioning stopper 20 and the tip of the bar BL, and the misalignment determination ECK is performed to determine whether or not there is any misalignment at the tip of the bar BL from the image GZ photographed by the image sensor 78 at the end of the positioning process PC. As a result, when cutting multiple bar stocks, any occurrence of misalignment in the cutting length is detected before cutting, thereby preventing the outflow of products with defective cut lengths.

[0056] Furthermore, according to the bar cutting device 10 of this embodiment, the positioning stopper 20 is movable longitudinally on the conveying surface 14a to an upper position UP that is at least a predetermined height h above the lower position LP at which the positioning stopper 20 abuts against the leading end of the bar BL. When the positioning stopper 20 is moved to the upper position UP, the positioning stopper 20 does not interfere with the image capturing area of ​​the image sensor 78. This allows the misalignment determination ECK to be performed appropriately, since the positioning stopper 20 is moved to the upper position UP and does not interfere with the image capturing area of ​​the image sensor 78. Furthermore, by moving the positioning stopper 20 longitudinally, the cutting length L of the bar BL can be changed to the desired length. Furthermore, by moving the positioning stopper 20 to the upper position UP after cutting the bar BL, the cut bar BL can be easily discharged by the discharge conveyor 14.

[0057] Furthermore, according to the bar cutting device 10 of this embodiment, the misalignment determination ECK is performed by detecting each end face BF of the bar BL from the photographed image GZ by image processing, and determining that there is no misalignment at the tip of the bar BL if the number of detected end faces BCT, which is the number of detected end faces BF present within a predetermined area GN in the photographed image GZ, is equal to the value of the predetermined number N, and determining that there is misalignment at the tip of the bar BL if it is smaller than the value of the predetermined number N. This allows the misalignment determination ECK to be performed appropriately.

[0058] Furthermore, according to the bar cutting device 10 of this embodiment, if it is determined by the misalignment determination ECK that there is no misalignment at the tip end of the bar BL, the cutting process CC is performed, and if it is determined that there is misalignment at the tip end of the bar BL, a retry process RTC is performed in which the bar BL is transported a predetermined distance BD in the upstream direction and then the positioning process PC is performed again. This prevents products with an incorrect cut length from being output, and allows the bar cutting device 10 to continue operating without stopping even if there is misalignment at the tip end of the bar BL.

[0059] Furthermore, the bar cutting device 10 of this embodiment is equipped with a notification device 34 for when an abnormality occurs, and when the retry count RCT of the retry process RTC reaches a predetermined number of times NGCT or more, the notification device 34 notifies the occurrence of the abnormality and automatically stops the device. This prevents the outflow of products with defective cut lengths, and also properly performs the stop process when recovery is impossible using the retry process RTC.

[0060] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the present invention is not limited to this embodiment and can be implemented in other modes.

[0061] For example, in the above-described embodiment, the image sensor 78 was positioned to photograph the tip of the bar material BL from diagonally above (photographing angle θ), but this is not limited to this, and the image may be photographed from, for example, vertically above the tip of the bar material BL (θ=90°), and the image sensor 78 may be appropriately positioned to suitably determine misalignment.

[0062] In addition, in the above-described embodiment, the detection mechanism 76 detects the approach of the bar BL to the positioning stopper 20, but the approach of the bar BL to the positioning stopper 20 may be detected from the captured image GZ of the image sensor 78, for example. In this case, the detection mechanism 76 does not need to be installed.

[0063] Furthermore, in the above-described embodiment, there is only one carry-out conveyor 14, but a plurality of carry-out conveyors 14 may be provided in the x-axis direction (conveying direction), and the bar BL may be transported across the carry-out conveyors 14. In this case, an anti-reflection plate or the like is appropriately provided in the gaps in the conveying surfaces between the plurality of carry-out conveyors 14 to prevent the captured image GZ from being distorted by reflected light or the like.

[0064] Furthermore, in the above-described embodiment, the bar material BL is a deformed reinforcing bar, but it may be a rod-shaped steel material, etc. Even with a rod-shaped steel material, there is variation in the cross-sectional shape, and the same problem occurs.

[0065] In the above-described embodiment, the predetermined number N of the bars BL is four, but it is not necessarily limited to four, and the present invention is applicable even to a single bar.

[0066] The above is merely one embodiment, and although other examples will not be given, the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art within the scope of the present invention. [Explanation of symbols]

[0067] 10: Bar cutting device 12: Intake conveyor 14: Discharge conveyor 14a: conveying surface 16: Cutting machine 20: Positioning stopper 34: Notification device (notification means) 78: Image sensor BCT: Number of evenly spaced pieces BD: Predetermined distance BF: Edge BL: Bar material ECK: Irregularity judgment GZ: Photographed image h: specified height L: Cutting length LP:Lower position N: Predetermined number NGCT: Predetermined number of times PC: Positioning process RCT: Retry count (number of repetitions) RTC: Retry processing UP: Upper position

Claims

1. a cutter provided between the carry-in conveyor and the carry-out conveyor and configured to simultaneously cut the bar materials; and a positioning stopper provided on a conveying surface of the carry-out conveyor so as to be movable relative to the conveying surface, the positioning stopper contacting the tip of the bar material being conveyed downstream and restricting the bar material from moving downstream; wherein the bar material is conveyed from the upstream side through the cutter to the downstream side, and a positioning process is performed in which the tip of the bar material is brought into contact with the positioning stopper to determine the cutting length of the bar material, and then the bar material is cut by the cutter, an image sensor is provided above the contact position between the positioning stopper and the tip of the bar material to capture an image of the periphery of the tip of the bar material, and an irregularity determination is performed to determine whether or not there is irregularity in the position of the tip of the bar material from the image captured by the image sensor at the end of the positioning process; The determination of misalignment is performed by detecting each end face of the bar material from the photographed image by image processing, and determining that there is no misalignment at the tip end of the bar material if the number of detected end faces, which is the number of detected end faces present in a predetermined area in the photographed image, is equal to the value of the predetermined number, and determining that there is misalignment at the tip end of the bar material if the number is smaller than the value of the predetermined number. A bar cutting device characterized by:

2. The positioning stopper is movable in the longitudinal direction on the conveying surface and is movable to an upper position that is a predetermined height or more above a lower position where the positioning stopper abuts against the tip of the bar material, and when moved to the upper position, the positioning stopper does not interfere with the photographing area of ​​the image sensor.

2. The bar cutting device according to claim 1.

3. If it is determined that there is no misalignment at the tip end of the bar material as a result of the misalignment determination, the bar material is cut by the cutting machine, and if it is determined that there is misalignment at the tip end of the bar material, a retry process is performed in which the bar material is transported a predetermined distance in the upstream direction and then the positioning process is performed again.

3. The bar cutting device according to claim 1 or 2.

4. The bar cutting device is provided with a means for notifying when an abnormality occurs, and when the number of times the retry process is repeated reaches a predetermined number, the notifying means notifies of the occurrence of an abnormality and the device automatically stops.

4. The bar cutting device according to claim 3.

Images