JP2001002305A - Defective part removing method and device for can- making metallic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defect detecting device for a metallic sheet for detecting the existence of a defective shape to remove a cut piece in accordance with the defective shape, in a cutting process for the metallic sheet. SOLUTION: A defective part removing device for a can-making metallic sheet, for detecting the existence of the defect of a metallic sheet 4 to remove its defective portion, is equipped with a first carrying conveyer 1 for carrying the sheet 4 in a plane direction along two side edges 5 in parallel with each other, rollers contacting with the sheet 4 and movable along the shape of the sheet 4 itself, a judging device for judging the existence of the defective shape of the sheet 4 itself, based on the displaced quantity of the roller and an arm member following carrying the sheet 4, a first cutting device 53 for cutting the sheet 4 to obtain plural cut pieces 57, after the existence of the defective shape of the sheet 4 is judged, and a discharge device 58 for discharging a piece 57, in accordance with the side edges judged having a defective shape out of these pieces 57, outside a carrying path for the other pieces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for manufacturing a welded can body for cutting a metal sheet, curving the cut piece into a cylindrical shape, and welding the side edges of the metal sheet. The present invention relates to a method for removing a defective portion of a metal sheet for can making and a device for removing a defective portion of a metal sheet, which can detect the defect and remove the defective portion.

[0002]

2. Description of the Related Art Conventionally, in manufacturing a three-piece can body, a plurality of cut pieces are manufactured by cutting a metal sheet having a rectangular shape in a plane in a conveying direction, and these cut pieces are bent into a cylindrical shape. There is known a method of manufacturing a can body by bringing the side edges into contact with each other and welding. An example of an apparatus used in the manufacturing process of such a welding can body is described in Japanese Utility Model Publication No.
No. 1-9868, JP-A-60-137762, and JP-A-62-141416. Japanese Utility Model Publication No. 61-9868 discloses an apparatus for stacking decorated metal sheets in the thickness direction, while Japanese Patent Application Laid-Open No. 60-137762 and Japanese Utility Model Application Laid-Open No. Sho 62-141416. The publication describes an apparatus for cutting metal sheets.

[0003] By the way, a metal sheet used for such a can body is preliminarily coated with a print coating. In the coating process, a mist (insulating material such as ink or paint) is applied to a portion that does not need to be printed. Object) may adhere. Further, when a lot of stacked metal sheets is transported to a processing step by a forklift or the like, or when the metal sheet is set at a predetermined position in the processing step, the metal sheet and a surrounding object or a processing apparatus are not used. There is a possibility that the four corners of the metal sheet are bent due to contact with the frame.

[0004] As described above, if a cut piece is manufactured by cutting a metal sheet having a defective portion and the cut piece is welded, poor welding may occur and the product quality of the can body may be degraded. Therefore, a cut piece with a defective part in the welding target part,
One example of a method that can be eliminated during the manufacturing process of the can body is described in Japanese Patent Application Laid-Open No. 2-227649. The method of removing a defective portion described in this publication is to detect the presence or absence of mist in an unpainted portion of a metal sheet that has been subjected to print painting, and a pair of upper and lower continuity check rolls are arranged in contact on both surfaces of the unpainted portion. Then, current is applied between the rolls via the sheet to be detected, and the mist on the sheet surface releases the rolls from the sheet surface and cuts off the current, thereby detecting the presence or absence of mist. By discharging the cut piece corresponding to the metal sheet in which the mist is detected out of the process, the frequency of occurrence of poor welding is reduced.

[0005]

However, according to the invention described in Japanese Patent Application Laid-Open No. 2-227649, it is possible to detect a metal sheet having a deposit at a stage prior to the welding step of the can body. Although it is possible, a shape defect of the metal sheet itself, such as a bent metal sheet, cannot be detected, and this type of technique has not been proposed yet. As described above, when a cut piece obtained by cutting a metal sheet having a shape defect is conveyed to the welding process, a conveyance trouble such as a feed jam of the cut piece may occur, or a side edge of the cut piece may be electrically welded. There is a problem that cutting of a welding wire (electrode wire) or poor welding (such as underwelding) causes deterioration of the product quality of a welding can body. These inconveniences adversely affect the pre-process and post-process of the can body manufacturing line, resulting in unstable operation of the entire can manufacturing process.

Therefore, when a bent metal sheet is found in a lot in which a plurality of metal sheets are stacked, a bent metal sheet may be manually extracted from the stacked metal sheets. Conceivable. However, since the frictional force between the metal sheets due to the weight is strong, it is difficult to remove defective products, and there is a possibility that the stacked metal sheets may be broken, and the extraction work is dangerous. For this reason, in the laminated metal sheet,
If a defective metal sheet is found, the metal sheet flows into the sheet feeder line as a single item,
The operator must temporarily stop the operation of the line and manually remove the defective metal sheet. Therefore, a great deal of labor and time are required to remove the defective metal sheet, and as a result, there is a problem that the manufacturing efficiency of the can body is reduced.

The present invention has been made in view of the above circumstances, and detects the presence or absence of a defective shape of a metal sheet, and detects a defective shape in a process of transporting a cut piece obtained by cutting the metal sheet. It is an object of the present invention to provide a method and an apparatus for removing a defective portion of a metal sheet for can making which can remove a cut piece at a corresponding portion.

[0008]

In order to achieve the above object, the invention according to claim 1 is for a can-making machine for detecting the presence or absence of a defect in a metal sheet being conveyed and removing the defective portion of the metal sheet. In the method of removing a defective portion of a metal sheet,
The metal sheet is conveyed in a planar direction along two mutually parallel side edges, and a shape detection device is brought into contact with the metal sheet near the two side edges on the surface of the metal sheet, With the conveyance, the presence or absence of a shape defect of the metal sheet itself is determined based on the operation state of the shape detection device in the thickness direction of the metal sheet,
Thereafter, the metal sheet is cut to produce a plurality of cut pieces, and among these cut pieces, the cut piece corresponding to the side edge determined to have the shape defect is placed outside the transport path of the other cut pieces. Is discharged.

According to a second aspect of the present invention, there is provided an apparatus for removing a defective portion of a metal sheet for can making which detects the presence or absence of a defect in the metal sheet and removes the defective portion of the metal sheet. And a transport device for transporting the metal sheet in a planar direction along two mutually parallel side edges, and contacting the other side of the metal sheet near the two side edges, and the metal sheet A shape detection device capable of operating in the thickness direction along the shape of the metal sheet, and determining the presence or absence of a shape defect of the metal sheet itself based on an operation state of the shape detection device accompanying conveyance of the metal sheet. And a cutting device that cuts the metal sheet to produce a plurality of cut pieces after determining the presence or absence of a shape defect of the metal sheet, and determines that there is a shape defect among the cut pieces. And the cut pieces comprising a side edge, and is characterized in that it comprises a discharge device for discharging outside the transport path of the other cut pieces.

According to the invention of claim 1 or claim 2,
While the metal sheet is being conveyed, the shape detection device operates in the thickness direction of the metal sheet following the shape of the metal sheet, thereby detecting the presence or absence of the shape defect. In addition, the metal sheet is continuously transported and cut, and a cut piece is obtained. Then, the non-defective cut piece corresponding to the side edge determined to have no shape defect is transported along the transport path, but the defective piece corresponding to the side edge determined to have the defective shape is The pieces are discharged out of the transport path while being distinguished from non-defective pieces.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, in a state where the shape detecting device is in contact with the metal sheet upstream of the shape detecting device in the transport direction of the metal sheet. And a biasing member for biasing the metal sheet toward the transfer device.

According to the third aspect of the invention, in addition to the same effect as the second aspect of the invention, the metal sheet moves in the thickness direction when detecting the presence or absence of a shape defect on the side edge of the metal sheet. Is suppressed.

According to a fourth aspect of the present invention, in addition to the configuration of the second or third aspect, the distance between the cutting device and the shape detecting device in the transport direction of the metal sheet is longer than the length of the metal sheet in the transport direction. Is also set to be long.

According to the fourth aspect of the present invention, the same operation as in the second or third aspect of the present invention is performed, and the metal sheet is cut after the presence or absence of the shape defect of the metal sheet is detected. For this reason, even if the metal sheet vibrates in the thickness direction due to the cutting of the metal sheet, the vibration does not affect the shape detection accuracy of the shape detection device.

[0015]

Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic plan view showing a metal sheet cutting step A1 provided in the three-piece can body manufacturing step. Here, as the metal sheet, a printing process (not shown) which is a process before the metal sheet cutting process A1 is used.
In the above, there are illustrated, for example, those directly subjected to a printing process with paint or ink, or those obtained by laminating a gravure printing film.

In the metal sheet cutting step A1, a first conveyor 1, a second conveyor 2, and a third conveyor 3 are provided. The first transport conveyor 1 is a so-called finger chain conveyor having a function of transporting a metal sheet 4 having a quadrangular (specifically, square or rectangular) planar shape in the planar direction. Specifically, the metal sheet 4 is conveyed in the direction of arrow B1 parallel to the two side edges 5 and 5 parallel to each other. The second conveyor 2 is a conveyor with fingers similar to the first conveyor 1, and has a function of conveying an important piece 57 described later in the direction of arrow B2. On the right side in the transport direction of the first transport conveyor 1, a lower guide member 32 is provided along the transport direction of the metal sheet 4. The transport surface of the transport conveyor 1 and the upper surface of the lower guide member 32 are flush with each other. Therefore, the lower surface 7 of the metal sheet 4
9 contacts the conveyor 1 and the lower guide member 32.

On both sides of the first conveyor 1 in the direction in which the metal sheet 4 is conveyed, shape detectors 6 and 6 are provided. The configuration of the shape detection devices 6 and 6 will be described based on the shape detection device 6 disposed on the right side in the transport direction of the metal sheet 4 for convenience. A frame 7 is provided on the side of the first conveyor 1, and the shape detection device 6 has a column 8 erected on the frame 7. A bed 9 is fixed to a side surface of the column 8 on the side of the first transport conveyor 1 by a screw member 9A, and a guide rail 10 parallel to the transport direction of the metal sheet 4 is provided on an upper surface of the bed 9. .

A movable table 11 is provided on the bed 9, and the movable table 11 can move along the guide rail 10. The movable base 11 has a plurality of elongated holes 12 penetrating in the thickness direction thereof. This long hole 12
Is extended in a direction parallel to the guide rail 10, and a screw member 13 inserted into the elongated hole 12 is screwed into a female screw (not shown) of the bed 9. Therefore, by loosening the screw member 13, the movable table 11 can be moved in the transport direction of the metal sheet 4, and the screw member 13 can be moved.
, The movable table 11 is fixed at a predetermined position in the transport direction of the metal sheet 4.

Further, at the end of the movable base 11 on the first conveyor 1 side, two notches 14 and 15 are formed extending in a direction perpendicular to the conveying direction of the metal sheet 4. Supports 16 and 17 that can move along the cutouts 14 and 15 are mounted on the movable base 11. Notches 1 are provided on the supports 16 and 17.
A plurality of long holes 18 and a plurality of long holes 19 extending in the same direction as 4 and 15 are separately formed. And the long hole 18
The screw member 20 inserted into the movable table 11 is screwed into the movable table 11 side, and the screw member 21 inserted into the elongated hole 19 is
Screwed on one side. Therefore, the screw member 20,
By loosening the support 21, the supports 16 and 17 can be moved in a direction perpendicular to the direction of transport of the metal sheet 4,
By tightening the screw members 20 and 21, the support base 1 is
6 and 17 are fixed at predetermined positions in a direction orthogonal to the transport direction of the metal sheet 4.

The support 16 is disposed upstream of the support 17 and the support 16 has the following configuration. A free end of the support base 16, that is, an upper end of the first conveyor 1, is provided with a joint plate 22.
Is attached. The joint plate 22 has a long hole 23 extending vertically. A screw member 24 inserted into the elongated hole 23 is screwed into a female screw (not shown) of the support base 16. Further, a bracket 25 is fixed to the lower end of the joint plate 22 by a screw member 22A.

On the other hand, the height adjustment mechanism 2 is
The height adjustment mechanism 26 includes an adjustment knob 27 and a shaft 28 that operates in the vertical direction by operating the adjustment knob 27. The bracket 25 is connected to a lower end of the shaft 28. Therefore, loosening the screw member 24 and adjusting the knob 2
By operating 7, the height of the bracket 25 can be adjusted. The bracket 25 is fixed at a predetermined height by tightening the screw member 24.

The bracket 25 has a support shaft 29 extending in the horizontal direction and perpendicular to the direction in which the metal sheet 4 is conveyed.
Is provided. Further, an arm member 30 that can rotate around the support shaft 29 is provided. A roller 31 that can rotate around a spindle 30A is attached to a free end of the arm member 30. Further, the tension spring 3 extends over a pin 25A formed on the bracket 25 and a pin 30B formed on the arm member 30.
Three have been bridged. With this tension spring 33,
The arm member 30 is biased counterclockwise about the support shaft 29.

Next, the structure of the support base 17 will be described. The free end of the support 17, that is, the lower guide member 3
A joint plate 34 is attached to an upper end of the second member 2. The joint plate 34 has an elongated hole 35 extending vertically. The screw member 36 </ b> A inserted into the elongated hole 35 is screwed into a female screw (not shown) of the support base 17. Further, a bracket 36 is fixed to a lower end portion of the joint plate 34 by a screw member 34A.

On the other hand, the height adjustment mechanism 3 is
The height adjustment mechanism 37 includes an adjustment knob 38 and a shaft 39 that operates in the vertical direction by operating the adjustment knob 38. The bracket 36 is connected to the lower end of the shaft 39.
Therefore, the screw member 36A is loosened and the adjustment knob 38
The height of the bracket 36 can be adjusted by operating. The bracket 36 is fixed at a predetermined height by tightening the screw member 36A.

The bracket 36 has a support shaft 40 extending in the horizontal direction and perpendicular to the direction in which the metal sheet 4 is conveyed.
Is provided. Further, an arm member (dog) 41 that can rotate around the support shaft 40 is provided. A roller 43 that can rotate about a support shaft 42 is attached to a free end of the arm member 41. Further, a pin 36B formed on the bracket 36
And a tension spring 44 is stretched over a pin 41A formed on the arm member 41. This tension spring 4
4 urges the arm member 41 counterclockwise about the support shaft 40. The rollers 31 and 43 having the above configuration are
With the transport of the metal sheet 4, the upper surface 80 near the side edge 5
Can roll in contact with Further, the distance between the center of the roller 31 and the center of the roller 43 is set to a value that is closer in consideration of space. This setting state can be adjusted based on the positional relationship between the support shafts 29 and 40 and the inclination angles of the arm members 30 and 41.

A displacement sensor (eddy current displacement sensor) 47 is attached to the bracket 36 via a plate 46. On the other hand, an iron plate (metal piece) 45 is attached to a side surface of the arm member 41 opposite to the first transport conveyor 1 in the vicinity of the displacement sensor 47. This displacement sensor 47 has a function of generating an eddy current according to the distance between the surface of the iron plate 45 and the magnetic field due to the electromagnetic induction when a high-frequency magnetic field is formed by energization. For this reason, the rotation of the arm member 41 changes the distance between the detection surface of the displacement sensor 47 and the iron plate 45, and the eddy current changes.

On the other hand, on the side of the lower guide member 32, that is, on the upper surface of the frame 7, a block 48 is provided along the transport direction of the first transport conveyor 1, as shown in FIG. The block 48 is fixed by a screw member 7A, and a holder 49 parallel to the lower guide member 32 is attached to a side surface of the block 48 on the lower guide member 32 side. The holder 49 has the first
A plurality of screw members 50 are vertically mounted along the conveying direction of the conveyor 1, and a plurality of side guide rollers 51 that can rotate around each of the screw members 50 are provided. Each side guide roller 51 is disposed between the lower guide member 32 and the frame 7, and has a lower side at the outer peripheral surface of each side guide roller 51, that is, at a height between the upper end and the lower end of the guide surface. The upper surface of the guide member 32 is set. Each side guide roller 51 has a gauge function for restricting the movement of the metal sheet 4 conveyed by the first conveyor 1 in the width direction.

By the way, the shape detecting device 6 disposed on the left side in the transport direction of the metal sheet 4 is basically similar in structure to the shape detecting device 6 disposed on the right side in the transport direction of the metal sheet 4. are doing. However, the point that the shape detecting device 6 disposed on the left side in the transport direction of the metal sheet 4 is not provided with components such as the block 48, the plate 49, the side guide rollers 51, and the screw members 50 is different from the metal sheet 4. 4 is different from the shape detection device 6 arranged on the right side in the transport direction.

A primary cutting device 53 is provided downstream of the shape detecting device 6 in the transport direction of the metal sheet 4 transported by the first transport conveyor 1. The primary cutting device 53 has a pair of upper and lower cutter rollers 54 and 55 as shown in FIG. The rotation center axes (not shown) of the cutter rollers 54 and 55 are orthogonal to the transport direction of the metal sheet 4 and are arranged horizontally. A plurality of cutters 56 are provided on the outer peripheral surfaces of the cutter rollers 54 and 55 at predetermined intervals in the axial direction. Further, a motor (not shown) for driving the cutter rollers 54 and 55 is provided. The cutter rollers 54 and 55 have a function of cutting the metal sheet 4 to be conveyed in the conveying direction, that is, the direction parallel to the side edge 5, to produce a plurality of important fragments 57.

Further, the downstream end of the shape detecting device 6 in the conveying direction of the metal sheet 4 (specifically, the roller 43
Of the metal sheet 4 in the transport direction of the metal sheet 4 between the downstream end of the metal sheet 4 and the upstream end of the primary cutting device 53 (specifically, the upstream end of the cutter rollers 54 and 55). It is set longer.

On the other hand, a discharge device 58 is provided on the discharge side of the important piece 57 in the primary cutting device 53.
The discharge device 58 includes a magnet conveyor 59 provided above the second conveyor 2, a discharge roller 61 driven by a motor 60, and a discharge tray 62. The magnet conveyor 59 has a plate 63 composed of an electromagnet, and a plurality of rollers 65 formed on the lower surface of the plate 63. Plate 63
, An attraction force is generated or released by control of energization or non-energization. Further, a stopper 66 is provided on the lower surface side of the plate 63 downstream of the important fragment 57 in the transport direction, corresponding to each important fragment 57. The stopper 66 is moved up and down by an actuator (not shown), and is controlled to protrude and retreat to a position where it comes into contact with the important piece 57 conveyed along the roller 65 and a position where it does not come into contact.

The discharge roller 61 is provided below the plate 63, and the discharge roller 61 is disposed in the discharge direction (arrow B1) of the important piece 57 discharged from the primary cutting device 53.
(Direction), it is disposed downstream of the second conveyor 2. The arrangement height of the discharge rollers 61 is set to a height between the plurality of rollers 65 and the second conveyor 2. Further, the discharge tray 62 is disposed downstream of the discharge roller 61 in the discharge direction of the important fragments 57. The discharge tray 62 is provided at the same height as the upper surface of the second conveyor 2.

The second transport conveyor 2 has a function of transporting the important fragments 57 by operating in a direction perpendicular to the first transport conveyor 1 (direction of arrow C1). A secondary cutting device 67 is provided in the middle of the transport path formed by the second transport conveyor 2. The secondary cutting device 67 includes a pair of upper and lower cutter rollers 6.
8,68A.

The pair of cutter rollers 68, 68A
Is configured to rotate about a horizontal rotation center axis that is orthogonal to the transport direction of the important piece 57. A plurality of cutters 6 are provided on the outer periphery of the pair of cutter rollers 68, 68A at predetermined intervals in the center axis direction.
9 are formed. Further, a motor (not shown) for driving the pair of cutter rollers 68, 68A is provided. This secondary cutting device 67 is used to
Is cut in the transport direction, so that a plurality of small cut pieces 70
Has the function of manufacturing.

Further, the third conveyor 3 is provided on the discharge side of the second conveyor 2, and the third conveyor 3 is provided with small cut pieces 70 discharged from the second conveyor 2 in the direction of arrow C1. Is transported in the direction of arrow D1 and sent to the welding step 71. In the welding step 71, a device (not shown) for bending the small cut piece 70 into a cylindrical shape and a welding wire (electrode wire;
(Not shown) and a supporting roller (not shown) around which the welding electrode is wound.

FIG. 6 is a block diagram showing a control system of the metal sheet cutting step A1. That is, the displacement sensor 47 is connected to the amplifier 72. This amplifier 72 has a span adjustment trimmer 73 and a zero adjustment trimmer 74. The amplifier 72 has a function of amplifying and outputting the signal of the displacement sensor 47. A detector control panel 75 is connected to the output side of the amplifier 72. The detector control panel 75 has an electronic control unit (ECU) 76 and a monitor 77.

The electronic control unit 76 comprises a microcomputer mainly comprising an arithmetic processing unit (CPU or MPU), a storage unit (ROM and RAM), and an input / output interface. further,
The output side of the electronic control unit 76 is connected to a discharge device 58 and an alarm indicator light 78. The warning indicator light 78 is arranged on the line side of the metal sheet cutting step A1, specifically, at a position where the operator can visually check.

Here, the correspondence between the configuration of this embodiment and the configuration of the present invention will be described. The lower surface 79 corresponds to one surface of the present invention, the first conveyor 1 and the lower guide member 32 correspond to the conveying device of the present invention, the upper surface 80 corresponds to the front surface or the other surface of the present invention, 43, the arm member 41, and the iron plate 45 correspond to the shape detecting device of the present invention, the important piece 57 corresponds to the cut piece of the present invention, and the second transport conveyor 2 corresponds to the transport path of the present invention. In addition, the displacement sensor 47, the amplifier 72, and the electronic control unit 76 correspond to the determination device of the present invention, the primary cutting device 53 corresponds to the cutting device of the present invention,
1 and the arm member 30 and the tension spring 33 correspond to the biasing member of the present invention.

Next, a method of detecting a defective shape of the metal sheet 4 itself and removing the defective portion will be described with reference to the flowchart of FIG. Before the metal sheet 4 is carried into the first conveyor 1, zero adjustment of the output voltage of the amplifier 72 with respect to the signal of the displacement sensor 47 and adjustment of the span (amplification ratio) are performed. First, at the time of zero adjustment of the output voltage of the amplifier 72, an eddy current is formed in the iron plate 45 by forming a high-frequency magnetic field by the displacement sensor 47 and allowing the magnetic flux to pass through the iron plate 45.
Is detected by Then, the iron plate 45 is brought into contact with the detection surface of the displacement sensor 47, and the zero adjustment trimmer 76 is operated so that the output voltage in this state becomes zero mv. In the span adjustment, the distance between the iron plate 45 and the detection surface of the displacement sensor 47 is set to 2 mm, and the span adjustment trimmer 77 is operated so that the output voltage in this state is 2,000 mv.

On the other hand, only one metal sheet 4 to be detected is placed on the conveyor 1, and the roller 31 is brought into contact with the upper surface 80 of the metal sheet 4. Then, the arm member 30 is set to be inclined such that the center of the support shaft 30 </ b> A is located downstream of the center of the support shaft 29 in the transport direction of the metal sheet 4. The angle between the vertical line (not shown) passing through the support shaft 29 and the arm member 30 on the acute angle side is 20 degrees or more.
It is set to 40 degrees, preferably 30 degrees. This arm member 3
The angle between 0 and the vertical line can be adjusted by operating an initial position setting mechanism (not shown).

When the roller 43 is in contact with the metal sheet 4, the center of the support shaft 42 is positioned more downstream than the center of the support shaft 40 in the direction in which the metal sheet 4 is conveyed. Tilt 41. The angle between the vertical line (not shown) passing through the support shaft 40 and the arm member 41 on the acute angle side is 20 to 40 degrees, preferably, the relative displacement amount of the iron plate 45 with respect to the displacement of the roller 43 ( Alternatively, it is set to 30 degrees, which is an angle at which the displacement ratio increases. The angle between the arm member 41 and the vertical line can be adjusted by operating an initial position setting mechanism (not shown).

Next, the heights of the rollers 31 and 43 are adjusted, and the reference voltage of the output voltage of the amplifier 72 is set (step S1). These rollers 31, 43
Is adjusted as follows. First,
A single 0.18 mm metal sheet 4 serving as a detection reference is placed on the first conveyor 1, and its side edge 5 and rollers 31 and 4 are placed.
The rollers 31 and 43 are moved orthogonally to the transport direction of the metal sheet 4 so that the end face of the block 3 on the block 48 side is flush with the end face. The movement of the rollers 31, 43 is performed by the horizontal movement of the support members 16, 17. further,
The rollers 31, 43 are positioned at such a height that the rollers 31, 43 contact the upper surface 80 of the metal sheet 4. The height adjustment of the rollers 31, 43 is performed by moving the brackets 25, 36 in the vertical direction. When the roller 31 is in contact with the upper surface 80 of the metal sheet 4, the amplifier 7
The output voltage of No. 2 is about 0 to 5 mv.

The setting of the reference voltage is performed as follows. The reference voltage of the amplifier 72 is the displacement sensor 4
Since the distance varies depending on the measurement distance between the center of the detection surface 7 and the iron plate 45, each measurement distance is set in accordance with the thickness of the metal sheet 4, and each reference distance is set in accordance with these measurement distances. You will set the voltage. Here, Table 1 shows an example of the relationship among the thickness of the metal sheet 4, the measured distance, and the reference voltage.

[0044]

[Table 1]

After step S1, the metal sheet 4
A threshold value used to determine the presence or absence of a shape defect is set (step S2). The threshold value is obtained by adding a deformation amount allowed by the metal sheet 4 to the reference voltage, and a value obtained by multiplying the reference voltage by the threshold value is set as the reference detection voltage. Then, when the output voltage of the amplifier 72 exceeds the reference detection voltage, the metal sheet 4 is handled as a defective determination target product. For example, if the threshold is 150
The reference detection voltage when set to% is obtained as follows: reference detection voltage = reference voltage × 1.5.

Further, in step S2, the deformed portion of the metal sheet 4 is detected by the displacement sensor 47. If the output voltage of the amplifier 72 corresponding to the deformed portion exceeds the reference detection voltage, the time during which the output voltage exceeds the reference detection voltage is detected. In order to determine whether the metal sheet 4 is defective according to the length, an upper limit time for the determination is set as a detection time (step S3). In other words, when the actual output voltage exceeds the reference detection voltage and the state is continuously detected beyond the detection time, it is determined that the metal sheet 4 is actually defective. Table 2 shows an example of the relationship between the reference detection voltage, the reference voltage, and the threshold.

[0047]

[Table 2]

After performing the above steps S1 to S3, the metal sheet 4 is loaded onto the first conveyor 1, and the metal sheet 4 is directed to the primary cutting device 53 by the first conveyor 1. Transport. In this case, the metal sheet 4 is transported in a state where the lower surface 79 is in contact with the lower guide member 32, and the one side edge 5 is in contact with the side guide roller 51, so that the metal sheet 4 is orthogonal to the transport direction. The movement in the direction is regulated. Then, the metal sheet 4 reaches the shape detecting device 6 before reaching the primary cutting device 53, and the leading end 4A of the metal sheet 4 in the transport direction is
And between the lower guide member 32 and the roller 4
3 and between the lower guide member 32 (step S
4).

Here, since the arm member 30 is inclined in the above-described direction, when the metal sheet 4 enters between the roller 31 and the lower guide member 32, the arm member 30 is smoothly moved in FIG. Then, the roller 31 rotates clockwise by a predetermined angle, and the roller 31 rolls along the upper surface 80 of the metal sheet 4. Further, in this case, the arm member 30 is attached to the support shaft 29 by the tension spring 33.
, The pressing force of the roller 31 acts in the direction of pressing the metal sheet 4 against the lower guide member 32.

Then, while the pressing force of the roller 31 is acting on the metal sheet 4, the front end 4 A of the metal sheet 4 enters between the roller 43 and the lower guide member 32. Then, the roller 43 rolls due to the conveying force, and the arm member 41 rotates a predetermined angle clockwise in FIG. 3 against the elastic force of the tension spring 44, and the roller 43 moves along the upper surface 80 of the metal sheet 4. To roll. Thus, when the arm member 41 rotates clockwise, the distance between the iron plate 45 and the displacement sensor 47 changes, and the signal of the displacement sensor 47 is amplified by the amplifier 72 to output a signal of a predetermined voltage.
In the electronic control unit 76, as shown in FIG.
During the passage time of one sheet of the metal sheet 4 (the roller 43
While the metal sheet 4 is present between the lower guide member 32 and the lower guide member 32), it is determined whether or not the output voltage amplified by the amplifier 72 exceeds the reference detection voltage (step S5). .

That is, when the bent portion M1 is present in at least one of the four corners of the metal sheet 4, the roller 43 is displaced upward along the shape of the bent portion M1. Therefore, the arm member 41 further rotates clockwise, and the distance between the displacement sensor 47 and the iron plate 45 increases. For this reason, the output voltage of the amplifier 72 becomes a value exceeding the reference detection voltage, and it is determined as Yes in step S5, and it is determined that the metal sheet 4 is a defective determination target product.

Further, it is determined whether or not the state in which the actual output voltage exceeds the reference detection voltage continues for more than the detection time (step S6). That is, if at least one of the defective determination target products whose time t shown in FIG. 8 exceeds the detection time is detected, Y is determined in step S6.
It is determined as es, and the metal sheet 4 is determined to be defective. Next, the output voltage waveform of the amplifier 72, the peak value of the output voltage, the number of the metal sheets 4 whose actual output voltage exceeds the reference detection voltage, and the defective portion determined as a defective product (any of the four corners) Then, a process of displaying the defect determination date, detection time, and the like on the monitor 77 is performed (step S7).

Further, it is determined whether or not the alarm indicator lamp 78 has been activated (step S8).
If it is determined to be es, the fact that a defect has been found in the metal sheet 4 is displayed by the warning indicator lamp 78 (step S).
9). After it is determined whether at least one of the four corners of the metal sheet 4 has a bend, the metal sheet 4 is conveyed to the primary cutting device 53. Then, the metal sheet 4 is cut by the cutter 56 to produce a plurality of important fragments 57.

By the way, as described above, the bent portion M1
If the metal sheet 4 determined to be present is cut,
It is determined whether or not the discharge device 58 has been activated (step S10). If the determination in step S10 is Yes, the important piece 5 manufactured by cutting the metal sheet 4 is manufactured.
7, the important piece 57 including the detected side edge 5 of the bent portion M1 is moved to the discharge tray 6 by the following operation.
2 (step S11).

That is, if it is determined that the metal sheet 4 in contact with the roller 43 is defective, the stopper 66 corresponding to the important piece 57 including its side edge is magnetically attracted to the magnet conveyor 59 and the roller 66 is attracted. It retreats to a position where it does not come into contact with the precious piece 57 conveyed along the lower surface of 65. Therefore, the important fragment 57 having the bent portion M1 is formed.
Passes through the position of the stopper 66 and passes through the magnet conveyor 5
9 and the roller 65 and the discharge roller 6
1 is conveyed. Then, the discharge roller 61 is rotated by driving the motor 60, and the important piece 57 is discharged to the discharge tray 62 by the discharge roller 61. The control in step S11 is performed in this manner, and this control routine ends.

The remaining important piece 57 is at a position where the corresponding stopper 66 is lowered without retreating, and the conveyed important piece 57 and the stopper 66 come into contact with each other, and the remaining important piece 57 is placed on the lower surface of the magnet conveyor 59. It stops at the position of the stopper 66 while being sucked and held. Then, the plates 63 corresponding to the remaining important fragments 57 are sequentially controlled to be in a non-energized state, fall on the second transport conveyor 2 with good timing, and are transported downstream by the second transport conveyor 2 as they are. . If the determination in steps S8 and S10 is No, the control routine ends.

On the other hand, if No is determined in step S5, that is, if no bend is detected in the side edge 5, the control routine ends without performing the control in steps S6 to S11. More specifically, all the stoppers 66 are at the lowered position without retreating, and each important piece 57 obtained by cutting by the primary cutting device 53 comes into contact with the stopper 66 and stops. Then, plate 63
Are sequentially controlled to be in the non-energized state, so that the important fragments 57 fall on the second conveyor 2, and the second
It is transported downstream by the transport conveyor 2.

In this way, the important fragments 57 transported by the second transport conveyor 2 are further cut in the transport direction by the secondary cutting device 67 to produce small cut pieces 70. These small cut pieces 70 are transported to the welding step 71 by the third transport conveyor 3, bent into a cylindrical shape, the side edges are overlapped, and the overlapped portion is welded to form a can body (not shown). Is manufactured.

As described above, at the stage before the first cutting of the metal sheet 4, it is determined whether or not the side edge 5 is bent, and thereafter the metal sheet 4 is cut. Then, only the important piece 57 including the side edge 5 determined to have the bent portion M1 is discharged to the discharge tray 62. Therefore, the small cut piece 70 conveyed to the welding process 71 does not have a bend, so that a conveyance trouble such as a feed jam can be avoided, and a welding wire (electrode wire) for electric welding is cut or a welding defect ( Underwelding) can be prevented beforehand, and the product quality of the welding can body can be improved.

The first conveyor 1, the second conveyor 2, and the third conveyor 3 are kept operating, and the first cutting device 53 and the second cutting device 67 are operated. In addition, the important piece 57 having the bent portion M1 can be discharged out of the production line of the can body without disturbing the pre-process and the post-process. Therefore, the operation state of the entire can manufacturing process is stabilized, and the manufacturing efficiency can be improved.

Further, a roller 31 for pressing the metal sheet 4 against the lower guide member 32 is provided upstream of the roller 43 in the transport direction of the metal sheet 4. Therefore, when the bending of the metal sheet 4 is detected by the roller 43, the metal sheet 4 is prevented from vibrating in the vertical direction (thickness direction), and the detection accuracy of the bending of the metal sheet 4 is improved. Can be avoided.

After the detection of the deformation of the metal sheet 4 is completed, the primary cutting of the metal sheet 4 is started. Therefore, during detection of the presence or absence of deformation of the metal sheet 4, the occurrence of a so-called disturbance in which the transport speed of the metal sheet 4 changes or vibrates, is avoided, and the detection accuracy of the presence or absence of deformation can be improved.

Further, since only the important piece 57 having the bent portion M1 is discharged out of the process without removing one sheet of the metal sheet 4 having the bent portion M1 out of the process at a time, waste of the metal material is eliminated. Can be suppressed, and the production cost of the can body can be suppressed, which is economical. Furthermore, without making the detection sensor directly contact the bent part,
Based on the displacement of the roller 43 (that is, the arm member 41),
Since the configuration in which the presence or absence of the bending of the metal sheet 4 is indirectly determined is employed, the detection surface of the displacement sensor 47 can be prevented from being damaged, and the durability thereof is improved.

In this embodiment, the shape detecting device 6 is disposed upstream of the primary cutting device 53, and after the metal sheet 4 has passed through the primary cutting device 53, the important fragment having the bent portion M1 is formed. 57 is discharged out of the transport path. If it is possible to avoid occurrence of disturbance to the detection signal, such as vibration caused by the transport of the important fragment 57,
The shape detecting device 6 is disposed between the secondary cutting device 67 and the discharge device 58, and after the small cutting piece 70 passes through the secondary cutting device 67, the small cutting piece 70 having the bent portion is moved out of the transport path. Can also be discharged. The important fragments 57 discharged out of the transport path may be scrapped as they are, but after processing into small cut pieces offline or the like,
If only the defective portion having the bent portion M1 is discarded, and the other portion is treated as a non-defective product, material loss due to discarding is reduced, which is economical.

In this embodiment, the vicinity of the left side edge 5 of the metal sheet 4 in the transport direction becomes a so-called discard area (scrap margin), and the discard area is cut by the primary cutting device 53. For this reason, even if the discarded area has some bends, no trouble is likely to occur in a subsequent process. However, the vicinity of the right side edge 5 in the transport direction of the metal sheet 4 does not become a discarded area on the gauge side, and even if there is a slight bend, a problem may occur in a subsequent process. Therefore, it is particularly effective to provide the shape detection device 6 on the right side in the transport direction of the metal sheet 4.

Since the arm members 30 and 41 are inclined in a predetermined direction, the roller 3
1, 43 smoothly roll along the shape of the metal sheet 4. Particularly, since the displacement of the roller 43 is easy, the shape of the metal sheet 4 can be detected with high accuracy. In addition,
In this embodiment, in addition to bending, deformation such as warpage or crushing can be detected.

[0067]

As described above, claim 1 or claim 2 is provided.
According to the invention, during the transportation of the stage before cutting the metal sheet, the shape detection device operates in the thickness direction of the metal sheet, the presence or absence of deformation of the side edge is determined, and then the metal sheet Is disconnected. Then, while the non-defective cut pieces determined to have no deformation are transported to the transport path,
Defective cut pieces corresponding to the side edges determined to be deformed are discharged out of the transport path while being distinguished from non-defective cut pieces. Therefore, there is no bend in the cut piece conveyed to the subsequent process, it is possible to avoid a conveyance trouble such as a feed jam, and to prevent a welding defect beforehand and improve the product quality of the welding can body. it can.

Further, it is possible to discharge bent cut pieces out of the production line of the can body without disturbing the pre-process and the post-process while the cutting device is operated while the metal sheet is being conveyed. it can. Therefore, the operation of the entire can making process is stabilized, and the production efficiency can be improved.

According to the third aspect of the invention, the same effect as that of the second aspect of the invention can be obtained. In addition, the metal sheet is urged to the lower guide member upstream of the contact device in the metal sheet transport direction. An urging member is provided. Therefore, when detecting the bending of the metal sheet by the contact device, the metal sheet is prevented from vibrating in the vertical direction (thickness direction), and the detection accuracy of the bending of the metal sheet is improved, and erroneous detection is avoided. Can be.

According to the fourth aspect of the invention, the same effects as those of the second or third aspect can be obtained, and the next cutting of the metal sheet is started after the detection of the presence or absence of the deformation of the metal sheet is completed. . Therefore, during detection of the presence or absence of the deformation of the metal sheet, the occurrence of a so-called disturbance, such as a change or vibration of the transport speed of the metal sheet, is avoided, and the detection accuracy of the presence or absence of the deformation can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an example of a can body manufacturing process to which the present invention is applied.

FIG. 2 is a plan view showing the configuration of the shape detection device shown in FIG.

FIG. 3 is a front view of the shape detection device shown in FIG. 2;

FIG. 4 is a side view of the shape detection device shown in FIG.

FIG. 5 is a side view of the discharging device shown in FIG. 1;

FIG. 6 is a block diagram showing a control circuit of the system of the present invention.

FIG. 7 is a flowchart showing an example of a metal sheet defect determination method according to the present invention.

FIG. 8 is a diagram showing an example of a relationship between an output voltage of an amplifier and a transit time of a metal sheet in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st conveyor, 2 ... 2nd conveyor, 4
... metal sheet, 5 ... side edge, 30, 41 ... arm member,
31, 43: roller, 32: lower guide member, 45
... iron plate, 47 ... displacement sensor, 57 ... important fragment, 5
8 Ejector, 72 Amplifier, 75 Electronic control unit
79 ... lower surface, 80 ... upper surface, L1 ... distance, L2 ...
length.

Claims (4)

[Claims] 1. A method for removing a defective portion of a metal sheet for can making which detects the presence or absence of a defect of a metal sheet to be conveyed and removes the defective portion of the metal sheet. The metal sheet is conveyed in the plane direction along the edge, and a shape detecting device is brought into contact with the metal sheet near the two side edges on the surface of the metal sheet, and the thickness direction of the metal sheet is conveyed with the conveyance of the metal sheet. Determine the presence or absence of a shape defect of the metal sheet itself based on the operation state of the shape detection device in,
Thereafter, the metal sheet is cut to produce a plurality of cut pieces, and among these cut pieces, the cut piece corresponding to the side edge determined to have the shape defect is placed outside the transport path of the other cut pieces. And removing the defective portion of the metal sheet for can making. 2. A device for removing a defective portion of a metal sheet for can making which detects the presence or absence of a defect of a conveyed metal sheet and removes a defective portion of the metal sheet, wherein one side of the metal sheet is supported, And a conveying device that conveys the metal sheet in a planar direction along two mutually parallel side edges; and a contact device near the two side edges on the other surface of the metal sheet, and the metal sheet itself. A shape detection device capable of operating in the thickness direction along the shape, and determining whether or not there is a shape defect in the metal sheet itself based on an operation state of the shape detection device accompanying the conveyance of the metal sheet. After determining the presence or absence of a shape defect of the metal sheet, a cutting device that cuts the metal sheet to produce a plurality of cut pieces, and it is determined that there is a shape defect among these cut pieces. The cut pieces containing edges, other cutting piece defective portion removing device of the metal sheet for can manufacturing, characterized in that a discharge device for discharging outside the transport path of the. 3. The metal sheet is urged toward the transfer device side in a state where the shape detection device is in contact with the metal sheet upstream of the shape detection device in the transfer direction of the metal sheet. 3. The apparatus for removing defective portions of a metal sheet for cans according to claim 2, further comprising an urging member that is provided. 4. The apparatus according to claim 2, wherein a distance between the cutting device and the shape detecting device in a direction in which the metal sheet is transported is set to be longer than a length in the transport direction of the metal sheet. 5. The apparatus for removing defective portions of a metal sheet for a can according to claim 1.