JP2017019003A - Safety device and press-forging machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate an interference between a die and a human body without decreasing a work safety degree.SOLUTION: A safety device 45 comprises: an imaging device for capturing a subject through a fisheye lens 48 or a wide-angle lens to generate an image including the imaged subject; and an image processing device connected with the imaging device, and identifying an image of a human body according to a contour line in the image, and in response to a prediction indicating occurrence of an interference between the human body and a die of a press-forging machine, generating a notification signal. Since the fisheye lens 48 or the wide-angle lens has a wide visual field, the image can be formed in a wide range in a die width direction even when the imaging device is extremely close to the die of the press-forging machine.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a mechanical press, a hydraulic press, a forming machine, a bending machine, a press brake, a forging machine including other metal working machines and a metal forming machine, and a safety device used in the forging machine.

  In the press brake described in Patent Document 1, CCD cameras are installed on the left and right hydraulic cylinders, respectively. The CCD camera includes a mold nearest area, a mold far area and a mold blade area set in advance in the horizontal direction, and a mold upper area, a blade area and a mold lower area set in the vertical direction in advance. Capture the subject over a wide area. An operator's hand is specified based on the captured image. Depending on the hand identified, hand and mold interference is expected.

JP 2008-207253 A

  In Patent Document 1, the CCD camera is disposed above a ram that holds an upper die (punch). Imaging is attempted from a position considerably away from the mold. In this way, a wide range of subjects are imaged despite a narrow viewing angle. However, with such an arrangement, the mold is hidden by the ram, the space around the mold cannot be imaged, and the approach of the human body to the mold cannot be accurately predicted.

  According to some aspects of the present invention, it is possible to provide a safety device that can accurately estimate the interference between the mold and the human body without causing a reduction in the safety level of work.

  In one embodiment of the present invention, an image of a subject is captured through a fish-eye lens or a wide-angle lens, an image sensor that generates an image in which the subject is reflected, and an image of a human body is specified by a contour line in the image. In addition, the present invention relates to a safety device including an image processing device that generates a notification signal when an interference between the human body and a forging machine is predicted.

  Since a fish-eye lens or a wide-angle lens has a wide viewing angle, an image is formed in a wide range in the width direction of the mold even if the imaging device is considerably close to the mold of the forging machine. The space around the mold can be reliably imaged. The movement of the worker can be grasped at a position close to the mold. Thus, the interference between the human body and the mold is predicted with high accuracy.

  The safety device may include a housing that houses the image sensor and has a flat outer surface that is partitioned with a predetermined posture with respect to the photosensitive surface of the image sensor. When the casing is attached to the forging machine, the image sensor can be attached in a determined posture according to the contact with the outer surface. The position of the photosensitive surface can be fixed relative to the mold. As a result, the course of the mold and the support that holds the mold in the image captured by the image sensor can be uniquely specified. Here, the perpendicular (generally equal to the optical axis) perpendicular to the photosensitive surface of the image sensor may be set parallel to the vertical plane.

  The image processing device may specify a virtual plane extending in parallel in the linear path of the type by a continuous or discontinuous line of pixels. In real space, when the human body stays in the path of the mold, the mold and the human body interfere with each other as the mold progresses. Therefore, once the human body is detected in the course, if the mold stops, the interference between the mold and the human body is avoided. Here, the virtual plane separates the path of the mold and the support that holds it from the rest. Therefore, if the image of the human body crosses the line, the approach of the human body can be reliably detected with respect to the path of the mold and the support tool. At this time, the pixels in a row may be arranged in a straight line through the optical axis of the fisheye lens or wide-angle lens. As a result, the calculation process is simplified. The computational load is reduced.

  In the safety device, the virtual plane may be parallel to the direction of gravity. In this way, the path of the mold and the support for holding it is partitioned by the vertical plane.

  The safety device may include a plurality of arithmetic circuits connected in parallel to the plurality of photoelectric conversion elements included in the imaging element. The photoelectric conversion element detects the amount of light (brightness) for each element. An electrical signal is output according to the amount of light. The arithmetic circuit realizes parallel processing of electric signals. As a result, real-time image processing is realized in units of frames.

  Another aspect of the present invention includes a mold supported by a frame, an imaging device that captures an image of a subject through a fish-eye lens or a wide-angle lens, and an image that reflects the subject. The present invention relates to a forging machine including an image processing device that generates a notification signal when an image of a human body is specified by the outline of the human body and an interference between the human body and the mold is predicted.

  As described above, according to the disclosed apparatus, it is possible to accurately estimate the interference between the mold and the human body without causing a reduction in work safety.

It is a front view showing roughly composition of a press brake as a forge pressure machine concerning a 1st embodiment. It is an expanded sectional view along line 2-2 in FIG. FIG. 3 is an enlarged cross-sectional view taken along line 3-3 in FIG. 1. It is a figure which shows notionally the relative positional relationship of the photosensitive surface of an image pick-up element, a positioning surface, and the end surface of an attachment member. It is a block diagram which shows the flow of a signal roughly. It is a conceptual diagram which shows roughly the positional relationship of the course of a punch and a virtual plane. It is a conceptual diagram which shows roughly a specific example of image processing. It is a block diagram which shows roughly the structure of the image pick-up element and arithmetic element which concern on one specific example. It is a block diagram which shows roughly the structure of the arithmetic circuit which concerns on one specific example. FIG. 4 is a side view schematically showing another embodiment of the safety device corresponding to FIG. 3. FIG. 4 is a side view schematically showing another embodiment of the safety device corresponding to FIG. 3. It is a front view which shows roughly the structure of the press machine as a forging machine which concerns on 2nd Embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

(1) Configuration of Forging Machine According to First Embodiment FIG. 1 schematically shows a press brake 11 as a forging machine according to the first embodiment. The press brake 11 includes a frame 12. The frame 12 is installed on the floor surface FL of a factory or other building. The frame 12 includes a guide frame 13. The guide frame 13 extends parallel to the direction of gravity. The direction of gravity is orthogonal to the floor surface FL, for example.

  The press brake 11 includes a table 14 and a ram 15. The table 14 is fixed to the frame 12 in a stationary manner. A mold, that is, a die 16 is mounted on the table 14 upward. The die 16 is detachably attached to the table 14. The die 16 is made of a steel material such as SCM.

  The guide frame 13 supports the ram 15. The ram 15 is attached to the guide frame 13. The guide frame 13 guides the linear vertical movement of the ram 15 parallel to the direction of gravity. A die, that is, a punch 17 is mounted on the ram 15 downward. The punch 17 may be detachably attached to the ram 15. The punch 17 is opposed to the die 16. As the ram 15 moves up and down, the punch 17 can approach the die 16 or move away from the die 16. A metal plate material is sandwiched between the punch 17 and the die 16 to be bent. The punch 17 is made of a steel material such as SCM.

  A pair of left and right hydraulic cylinders 18 are fixed to the frame 12. The space of the hydraulic cylinder 18 is divided by the piston 21 into a first hydraulic chamber 22 and a second hydraulic chamber 23. The piston 21 moves up and down in the space of the hydraulic cylinder 18 according to the action of the hydraulic pressure in the first hydraulic chamber 22 and the second hydraulic chamber 23.

  A piston rod 24 is coupled to the piston 21. The piston 21 is connected to the ram 15 by a piston rod 24. As the piston 21 moves up and down, the ram 15 moves up and down.

  A hydraulic circuit 25 is connected to the hydraulic cylinder 18. The hydraulic circuit 25 includes an oil pump 26 and an oil tank 27. The oil pump 26 is connected to the hydraulic cylinder 18 through a flow control valve 28 and a switching valve 29. When the hydraulic pressure acts on the first hydraulic chamber 22, the piston 215 descends. The ram 15 descends along the guide frame 13 as the piston 21 descends. When the hydraulic pressure acts on the second hydraulic chamber 23, the piston 21 rises. When the piston 21 rises, the ram 15 rises along the guide frame 13.

  An NC device 31 is connected to the hydraulic circuit 25. The NC device 31 controls the operation of the oil pump 26, the flow control valve 28 and the switching valve 29. The vertical movement of the ram 15 is controlled according to the operations of the oil pump 26, the flow control valve 28 and the switching valve 29.

  A plurality of intermediate plates 32 are fixed to the lower end of the ram 15. A reference surface 32 a is formed on the intermediate plate 32. The reference surface 32a has a flat surface. The plane extends parallel to the direction of gravity G. One vertical plane including the plane of the reference plane 32a is defined in common for the plurality of intermediate plates 32. When the ram 15 is displaced in the vertical direction, the plane of the reference surface 32a moves within one vertical plane.

  A clamp fitting 33 is individually attached to the intermediate plate 32. The clamp fitting 33 is bolted to the intermediate plate 32. Two bolts 34 are used for bolt tightening. The bolts 34 are arranged at intervals in the horizontal direction for each clamp fitting 33.

  As shown in FIG. 2, the punch 17 is sandwiched between the intermediate plate 32 and the clamp fitting 33. The punch 17 is held on the ram 15 by the clamping force of the clamp fitting 33. The clamp fitting 33 presses the punch 17 against the reference surface 32 a of the intermediate plate 32.

  An auxiliary reference surface 32 b is formed on the intermediate plate 32. The auxiliary reference surface 32b faces downward. The auxiliary reference surface 32b has a flat surface. The virtual surface 35 including at least a plane is orthogonal to the virtual surface including the reference surface 32a. An intersection line between the virtual surface 35 and the reference surface 32a defines a straight horizontal reference line 36 in the width direction of the mold. The punch 17 contacts the intermediate plate 32 at the reference surface 32a and the auxiliary reference surface 32b. The posture of the punch 17 is fixed with respect to the ram 15 by the action of the reference surface 32a and the auxiliary reference surface 32b.

  A pressure surface 37 that contacts the workpiece is formed on the punch 17. The pressurizing surface 37 may correspond to, for example, the maximum contact surface with the workpiece. The punch 17 is opposed to the die 16 at the pressing surface 37. A ridge line 38 is defined on the pressing surface 37 according to the form of processing. The ridge line 38 is positioned parallel to the horizontal reference line 36. A plurality of ridge lines may be formed on the pressing surface 37. At this time, the ridge lines extend in parallel to each other. A curved surface may be formed in addition to or instead of the ridgeline. The generatrix of the curved surface is defined parallel to the horizontal reference line 36.

  An alignment surface 41 is defined on the front side of the punch 17. The alignment surface 41 is a flat surface. The alignment surface 41 extends parallel to the ridge line 38 of the pressure surface 37. In addition, the alignment surface 41 is positioned parallel to the gravity direction G.

  The lower edge of the alignment surface 41 is connected to the pressure surface 37 by the auxiliary surface 42. The auxiliary surface 42 forms a space between the auxiliary surface 42 and a virtual plane 43 that contacts the edge 37 a of the pressing surface 37. The auxiliary surface 42 faces the die 16 in the same manner as the pressing surface 37.

(2) Configuration of Safety Device As shown in FIG. 3, a safety device 45 is incorporated in the press brake 11. The safety device 45 includes a camera unit (imaging unit) 46. The camera unit 46 is attached to the ram 15. In mounting, the housing 47 of the camera unit 46 is positioned with respect to the punch 17. In positioning, the housing 47 is received by the alignment surface 41 of the punch 17. The housing 47 may be formed from, for example, a hard resin body.

  The camera unit 46 includes a fisheye lens 48. The fisheye lens 48 is incorporated in the housing 47. The optical axis 51 of the fisheye lens 48 is aligned in the direction of gravity. Here, the angle of view of the fisheye lens 48 is set to 180 ° or more, for example. However, the angle of view of the fisheye lens 48 may be less than 180 °. In that case, when the camera unit 46 is mounted on the press brake 11, it is desirable that the lower edge of the alignment surface 41 of the punch 17 fits in the entire image. In addition, the optical axis 51 of the fisheye lens 48 may overlap the alignment surface 41 of the punch 17.

  A positioning surface 52 is defined in the housing 47. The positioning surface 52 is formed by a flat outer surface of the housing 47. The casing 47 is pressed against the alignment surface 41 of the punch 17 by the positioning surface 52. The positioning surface 52 extends parallel to the optical axis 51 of the fisheye lens 48.

  The housing 47 includes an attachment member 53. The attachment member 53 is opposed to the positioning surface 52 with a gap. A downward end surface 53 a is defined on the attachment member 53. The end surface 53 a extends in a virtual plane orthogonal to the optical axis 51 of the fisheye lens 48. When the camera unit 46 is mounted on the punch 17, the end surface 53 a of the attachment member 53 is abutted against the punch 17 by the virtual surface 35. At this time, when the positioning surface 52 of the housing 47 overlaps the alignment surface 41 of the punch 17, the optical axis 51 of the fisheye lens 48 faces the gravity direction G. The attachment member 53 may be formed from a metal plate material such as aluminum.

  A screw hole 54 is defined in the attachment member 53. The axial center 54 a of the screw hole 54 extends in parallel to a virtual plane orthogonal to the optical axis 51 of the fisheye lens 48. A screw 55 is screwed into the screw hole 54. The tip of the screw 55 is abutted against the punch 17. When the screw 55 is screwed in, the positioning surface 52 of the housing 47 is pressed against the alignment surface 41 of the punch 17 by the repulsive force. Thus, the housing 47 of the camera unit 46 is fixed to the punch 17. Instead of these fixing methods, other fixing methods may be used.

  As shown in FIG. 4, an image sensor (image sensor) 57 is accommodated in the housing 47. The image sensor 57 has a photoelectric conversion element, that is, an array of photodiodes. Here, each photodiode corresponds to one pixel. For example, a specific color filter is associated with each photodiode. The photodiode detects the amount of light for each RGB color. The detected light quantity is converted into an electrical signal. In addition, one pixel may be grasped by a group of three primary colors such as RGGB.

  The light receiving surface of the array forms a photosensitive surface 58 of the image sensor 57. The photosensitive surface 58 is orthogonal to the optical axis 51 of the fisheye lens 48. A subject is projected onto the photosensitive surface 58 through the fisheye lens 48. Thus, the image sensor 57 images the subject through the fisheye lens 48. An image is generated based on the projected image of the subject. The subject appears in the image.

  On the photosensitive surface 58, one pixel row 59 is specified. The pixel column 59 includes a continuous or discontinuous column of pixels. A row of pixels 61 is arranged in a straight line. The pixel column 59 corresponds to the horizontal line 63 in the image 62. This horizontal line 63 passes through the center of the image 62. Therefore, the horizontal line 63 bisects the image 62 up and down. The pixel row 59 is arranged in parallel to the positioning surface 52 and the end surface 53 a of the attachment member 53. As a result, when the camera unit 46 is mounted on the press brake 11 in a determined posture, a virtual plane that extends parallel to the linear path of the punch 17 is projected onto the pixel row 59.

  As shown in FIG. 5, the safety device 45 includes an image processing device 64. The image processing device 64 is incorporated in the housing 47 of the camera unit 46, for example. The image processing device 64 can be configured as one semiconductor chip. The image processing device 64 is connected to the image sensor 57. The image processing device 64 specifies an image of the human body with the contour line in the image 62. The human body can be, for example, an operator's hand or finger or other body part. A general edge detection method may be used for the contour detection. The image processing device 64 performs image processing in real time.

  The camera unit 46 is electrically connected to the NC device 31 by wiring or wirelessly. Communication is established between the camera unit 46 and the NC device 31 through wiring or radio. When the image processing device 64 predicts the interference between the human body and the punch 17, the image processing device 64 generates a notification signal. The generated notification signal is transmitted from the image processing device 64 to the NC device 31. The NC device 31 performs a specific operation in response to receipt of the notification signal. Specific operations include a sudden stop of the ram 15.

  For example, as shown in FIG. 6, in the prediction, the image processing device 64 specifies a virtual plane 66 extending in parallel with the linear path 65 of the punch 17. For example, the pixel row 59 described above defines a virtual plane 66 that extends parallel to the linear path 65 of the punch 17. The optical axis of each pixel 61 is included in the plane of the virtual plane 66. The virtual plane 66 draws a horizontal line 63 in the image 62. The virtual plane 66 partitions a space layer 67 having a predetermined thickness t that is overlapped on the front side of the path 65 of the punch 17. If the human body image intersects the horizontal line 63 in the image 62, the approach of the human body to the spatial layer 67 is detected. Thus, the approach of the human body to the path 65 of the punch 17 is reliably detected. The degree of approach can be adjusted by the thickness t of the space layer 67.

  In addition, the image processing device 64 may generate a preliminary signal when the punch 17 is recognized as a subject in the image 62. The NC device 31 can not start the vertical movement of the ram 15 unless it receives a preliminary signal. By using such a spare signal, the press brake 11 cannot start to operate unless the normal operation of the safety device 45 is confirmed.

(3) Operation of Safety Device Next, the operation of the safety device 45 will be briefly described. When the press brake 11 is used, the camera unit 46 is fixed to the punch 17 in a predetermined posture. In fixing, the positioning surface 52 of the housing 47 comes into surface contact with the alignment surface 41 of the punch 17. The end surface 53 a of the attachment member 53 is abutted against the punch 17 by the virtual surface 35. Thus, the optical axis 51 of the fisheye lens 48 is adjusted in the gravity direction G. A screw 55 is screwed into the screw hole 54.

  The image sensor 57 images the subject through the fisheye lens 48. The subject is reflected in the captured image 62. The image processing device 64 identifies the horizontal line 63 in the image 62. The horizontal line 63 may be specified by the coordinate value of the pixel row 59, for example.

  As shown in FIG. 7, the punch 17 is reflected as a subject in the image 62. In the image 62, the lower edge 41 a of the alignment surface 41 extends in parallel to the horizontal line 63. Since the lower edge 41 a of the alignment surface 41 extends in the horizontal direction parallel to the virtual plane 66, the distance between the lower edge 41 a and the horizontal line 63 is maximized at the center of the image 62, and goes toward the left and right edges of the image 62. The distance between the lower edge 41a and the horizontal line 63 is reduced. The image processing device 64 specifies the alignment surface 41. The specification of the alignment surface 41 is useful for generating a preliminary signal.

  During the work, the image 62 includes the material and the worker's human body (including a part thereof) as the subject. The image processing device 64 specifies the material image 68 a and the human body image 68 b by the contour line in the image 62. A general edge detection method may be used to detect the contour line. The image processing device 64 determines the positional relationship between the human body image 68b and the horizontal line 63 for each frame. When the human body image 68c intersects the horizontal line 63, an interference between the human body and the punch 17 is predicted, and a notification signal is generated. The notification signal is transmitted from the image processing device 64 to the NC device 31. The NC device 31 performs a specific operation in response to receipt of the notification signal. Here, for example, a control signal is transmitted from the NC device 31 to the switching valve 29. The control signal switches the position of the switching valve 29 and stops the supply of hydraulic pressure to the first hydraulic chamber 22. The control signal may further switch the switching valve 29 to start supplying hydraulic pressure to the second hydraulic chamber 23. Thus, the descending of the ram 15 stops suddenly. As a result, the occurrence of mutual interference between the punch 17 and the human body is reliably avoided.

  In the safety device 45 according to the present embodiment, the subject is imaged through the fisheye lens 48. Since the fisheye lens 48 has a wide viewing angle, an image is formed in a wide range in the width direction of the punch 17 even when the image sensor 57 is very close to the punch 17. The space around the punch 17 is reliably imaged. The movement of the operator is grasped at a position close to the punch 17. Thus, the interference between the human body and the punch 17 is predicted with high accuracy.

  The camera unit 46 has a positioning surface 52 and an end surface 53a that are partitioned in a predetermined posture with respect to the photosensitive surface 58 of the image sensor 57. Therefore, when the housing 47 is attached to the press brake 11, the image sensor 57 is attached in a determined posture according to the surface contact between the positioning surface 52 and the end surface 53a. The position of the photosensitive surface 58 is fixed relative to the punch 17. As a result, the spatial layer 67 superimposed on the path 65 of the punch 17 in the image 62 photographed by the image sensor 57 is uniquely specified. Here, since the perpendicular line perpendicular to the photosensitive surface 58 of the image sensor 57 (the optical axis 51 of the fisheye lens 48) is set parallel to the vertical plane, the spatial layer 67 is easily specified by the pixel row 59.

  In the real space, when the human body stays in the path 65 of the punch 17, the punch 17 and the human body are caused to interfere with the progress of the punch 17. Therefore, when the human body is detected in the path 65, if the progress of the punch 17 is stopped, the interference between the punch 17 and the human body is avoided. The virtual plane 66 separates the path 65 of the punch 17 from the rest by a space layer 67. Therefore, if the human body image 68 c intersects the horizontal line 63, the approach of the human body to the path 65 of the punch 17 is reliably detected. Here, since the pixel rows 59 are arranged in a straight line through the optical axis 51 of the fisheye lens 48, the calculation process is simplified in detecting the intersection. The computational load is reduced.

(4) Configuration of Real-Time Processing As shown in FIG. 8, the image processing device 64 may include a plurality of arithmetic circuits 72 connected in parallel to the plurality of photodiodes 71 in realizing the real-time processing. For example, the photodiodes 71 are arranged in an array of M rows and N columns. In addition to the array of photodiodes 71, an A / D converter array 73 is disposed on the image sensor 57. The A / D converter array 73 includes one A / D converter 74 for each group of photodiodes 71 in each row. That is, the A / D converter array 73 is formed by M A / D converters 74 in one column. Each A / D converter 74 converts the charge of the photodiode 71 into a voltage signal in turn for each row.

  An arithmetic element 75 is connected to the image sensor 57. The arithmetic element 75 includes a plurality of arithmetic circuits 72. Each arithmetic circuit 72 is individually connected in parallel to the corresponding photodiode 71. The arithmetic circuit 72 corresponds to the photodiode 71 on a one-to-one basis. Therefore, the arithmetic element 75 is formed of an arithmetic circuit 72 with M rows and N columns. A transfer shift register line 76 is added to the arithmetic circuit 72 for each row. Each transfer shift register line 76 includes N transfer shift registers 76a equal to the number of arithmetic circuits 72 included in one row. The transfer shift register 76a is connected in series within one line. Each transfer shift register 76 a is individually connected to a corresponding arithmetic circuit 72.

  A control circuit 77 is connected to the image sensor 57 and the arithmetic element 75. The control circuit 77 includes a CPU (central processing circuit) 78. The CPU 78 acquires the program 81 from, for example, the memory 79 when executing the parallel processing program for executing the parallel processing program. As the program 81 is executed, the CPU 78 implements functional blocks such as a program control unit 82 and an arithmetic processing unit 83.

  The program control unit 82 executes image capture processing and parallel processing of the arithmetic element 75. In the image capturing process, the program control unit 82 controls the operation of the drive circuit 84. The array of photodiodes 71 and the A / D converter array 73 capture an image by the action of the drive circuit 84. In parallel processing of the arithmetic element 75, the program control unit 82 controls data transfer of the transfer shift register 76a and arithmetic processing of the arithmetic circuit 72. A SIMD (single instruction and multi data stream) type parallel operation process is executed in accordance with the control. The arithmetic processing unit 83 performs necessary arithmetic processing during the execution of the program 81, and calculates feature amounts such as the center of gravity and area of the image and the discrimination operation according to the execution result of the program 81. The arithmetic processing unit 83 generates the aforementioned notification signal and spare signal.

  For example, as shown in FIG. 9, the arithmetic circuit 72 has a register matrix 85. The register matrix 85 stores digital signals from the corresponding shift register 76 a and the shift register 76 a of the adjacent arithmetic circuit 72. Each of the A latch 86 a and the B latch 86 b acquires a digital signal from the register matrix 85. An ALU (arithmetic logic unit) 87 calculates the difference. The calculation result is stored in the register matrix 85. The A latch 86a reads the difference from the register matrix 85, and the ALU 87 calculates the absolute value of the difference. The calculated absolute value is stored in the register matrix 85.

  The ALU 87 is a 1-bit arithmetic unit and has simple operation functions such as logical product (AND), logical sum (OR), exclusive logical sum (XOR), addition (ADD), and addition with Carry (ADC). Since complex calculations can be described as a combination of simple calculation functions, the ALU 87 is repeatedly operated while selecting one of the calculation functions. For example, multiplication is realized by repeating addition. The subtraction is realized by bit-inverting the number to be subtracted and adding 1 to make it a negative number, and adding this. The division is realized by, for example, bit shift (for example, when “the number to be divided is 8”, the bit is shifted to the right by 3 bits). The calculation of the absolute value is realized by adding 1 to the negative number (sign bit = 1).

  The photoelectric output from the photodiode 71 is sequentially sent to the A / D converter 74 for each row of photodiodes. The A / D converter 74 generates a digital signal corresponding to the photoelectric output. The digital signals are transferred to the transfer shift register 76a one after another for each row. When the transfer of one frame is completed, the digital signal is transferred from the transfer shift register 76a to the corresponding arithmetic circuit 72.

  In the arithmetic circuit 72, “edge detection” is performed. A two-neighbor operation is used for edge detection. A difference in intensity value is calculated between adjacent pixels. Thus, the image processing operation is realized by completely parallel processing. Images are processed at high speed. The intersection of the human body image and the horizontal line 63 can be detected in real time.

(5) Other Embodiments of Safety Device As shown in FIG. 10, a clamp fitting 33 may be used for attaching the camera unit 46. A housing 47 of the camera unit 46 is sandwiched between the intermediate plate 32 and the clamp fitting 33. The clamp fitting 33 presses the housing 47 of the camera unit 46 against the reference surface 32 a of the intermediate plate 32. The positioning surface 52 of the housing 47 is in surface contact with the reference surface 32 a of the intermediate plate 32. In addition, the housing 47 is at least in line contact with the auxiliary reference surface 32 b of the intermediate plate 32 at the virtual surface 35. The posture of the image sensor 57 is fixed with respect to the intermediate plate 32 by the action of the reference surface 32a and the auxiliary reference surface 32b. At this time, the optical axis 51 of the fisheye lens 48 faces the direction of gravity G. In this way, the photosensitive surface 58 of the image sensor 57 is fixed in a posture determined with respect to the punch 17.

  As shown in FIG. 11, the clamp fitting 33 may be omitted when the camera unit 46 is attached. At this time, the housing 47 of the camera unit 46 may be bolted to the intermediate plate 32. One or two bolts 91 may be used for bolt tightening. The bolt 91 is screwed into the intermediate plate 32. Thus, the housing 47 is sandwiched between the head of the bolt 91 and the intermediate plate 32. Here, the positioning surface 52 of the housing 47 may be in surface contact with the reference surface 32 a of the intermediate plate 32, and the housing 47 may be at least in line contact with the auxiliary reference surface 32 b of the intermediate plate 32 at the virtual surface 35. The posture of the image sensor 57 is fixed with respect to the intermediate plate 32 by the action of the reference surface 32a and the auxiliary reference surface 32b. The optical axis 51 of the fisheye lens 48 faces the direction of gravity G. In this way, the photosensitive surface 58 of the image sensor 57 is fixed in a posture determined with respect to the punch 17.

(6) Configuration of Forging Machine According to Second Embodiment FIG. 12 schematically shows a press machine 101 as a forging machine according to the second embodiment. The press machine 101 includes a frame 102. The frame 102 is fixed to a floor surface FL of a factory or other building. The frame 102 includes a guide frame 103. The guide frame 103 extends parallel to the gravity direction G.

  The guide frame 103 supports the slide 104. The slide 104 is attached to the guide frame 103. The guide frame 103 guides the linear vertical movement of the slide 104 in parallel with the gravity direction G. An upper mold 105 is mounted on the slide 104 downward. The upper mold 105 may be detachably attached to the slide 104. The upper mold 105 is made of a steel material such as SCM.

  A bolster 106 is supported on the frame 102. A lower mold 107 is detachably supported on the bolster 106. The lower mold 107 is opposed to the upper mold 105. As the slide 104 moves up and down, the upper mold 105 can approach the lower mold 107 or move away from the lower mold 107. The metal plate material is punched or bent between the upper die 105 and the lower die 107, or the metal lump is forged. The lower mold is made of a steel material such as SCM.

  A die cushion 108 is incorporated in the press machine 101. The die cushion 108 is opposed to the upper mold 105. When the upper mold 105 approaches the lower mold 107, the die cushion 108 receives the upper mold 105 elastically. For example, a metal plate material is held between the die cushion 108 and the upper mold 105.

  A hydraulic cylinder 109 is fixed to the frame 102. The piston of the hydraulic cylinder 109 is connected to the slide 104. In the hydraulic cylinder 109, the piston moves up and down in the space of the hydraulic cylinder 18 by the action of the hydraulic pressure acting on the piston. The vertical movement of the slide 104 is caused according to the vertical movement of the piston. The operations of the hydraulic cylinder 109 and the die cushion 108 are controlled by the NC device 110 through a hydraulic circuit.

  A safety device 112 is incorporated in the press machine 101. The safety device 112 includes a camera unit 46 as with the safety device 45 described above. A housing 47 of the camera unit 46 is attached to the slide 104, for example. When attaching, the housing 47 of the camera unit 46 is positioned with respect to the upper mold 105. The safety device 112 functions in the same manner as the safety device 45 described above. Therefore, the safety device 112 achieves the same effect as the safety device 45 described above.

  Although the press machine 101 has been described as a hydraulic press, the press machine 101 may be configured as a servo press or a crank press. Even in that case, the safety device 112 can be used. The safety device 112 functions in the same manner as described above. Further, in the safety devices 45 and 112, the fisheye lens 48 may be replaced with a wide-angle lens. Furthermore, the color of the skin or the color of the work gloves may be registered in the image processing device 64 in advance for detecting the contour. If the contour of the hand or finger is detected in accordance with the color detection in this way, the detection accuracy can be further improved. Furthermore, the actions of the downward end face 53a and the positioning face 52 can be established not only by the casing 47 itself as described above but also by the actions of other members added to the casing 47. Such other members are handled as a part of the housing 47.

  DESCRIPTION OF SYMBOLS 11 Forging machine (press brake), 17 type | mold (punch), 45 safety device, 46 imaging unit (camera unit), 47 housing | casing, 48 fisheye lens, 57 image pick-up element, 58 photosensitive surface, 59 1 line of pixels (pixel row), 62 images, 64 image processing devices, 65 path, 66 virtual plane, 68b human body image, 68c human body image, 71 photoelectric conversion element (photodiode), 72 arithmetic circuit, 101 forging machine (press machine), 105 type (top) Mold), 112 safety device, G gravity direction.

Claims (6)

An imaging device that captures an image of a subject through a fish-eye lens or a wide-angle lens and generates an image in which the subject is reflected;
An image processing device connected to the imaging device, for specifying an image of a human body by a contour line in the image, and generating a notification signal when an interference between the human body and a type of a forging machine is predicted. Safety device.   The safety device according to claim 1, further comprising a housing having a flat outer surface that accommodates the image sensor and is partitioned in a determined posture with respect to a photosensitive surface of the image sensor. apparatus.   3. The safety device according to claim 1, wherein the image processing device specifies a virtual plane extending in parallel in the linear path of the type by a continuous or discontinuous line of pixels.   4. The safety device according to claim 3, wherein the virtual plane is parallel to the direction of gravity.   The safety device according to any one of claims 1 to 4, further comprising a plurality of arithmetic circuits connected in parallel to the plurality of photoelectric conversion elements included in the imaging element. A mold supported by a frame;
An imaging device that captures an image of a subject through a fish-eye lens or a wide-angle lens and generates an image in which the subject is reflected;
An image processing device connected to the image pickup device, specifying an image of a human body with a contour line in the image, and generating a notification signal when an interference between the human body and the mold is predicted. Forging machine.

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