JP2010285205A - Can making system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means capable of simply setting positioning reference usable in various processes irrespective of a type of a workpiece or a process rank by an automatic scheme with a reduced facility cost burden and accurately and reliably detecting the positioning reference without contact in a can making system in an automatic line. <P>SOLUTION: In an automatic line for continuously manufacturing a can product, a can body or a can lid from a metallic raw material plate or its work through various processes, a reference mark is painted with fluorescent ink at a required position on the surface of the workpiece. An ultraviolet ray is irradiated to the workpiece during or before a required working process on a downstream of the line to make the reference mark luminous and the mark is detected by a fluorescent sensor. The position is determined by the detected reference mark for required machining. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a can manufacturing system for manufacturing various metal can products such as pail cans and square cans, a can body, a can lid, and the like, continuously and automatically from a metal original plate or a processed product thereof.

  In a can-making system using an automatic line, a workpiece is positioned during various types of processing in the middle of the line. In some cases, a specific part of the workpiece needs to be detected as a positioning reference. For example, in the automatic production line of pail can bodies, sheet feeder (original plate supply) → slitter (divided into can sizes) → cylindrical forming → seam welding → clear coating (rust prevention on the outer surface side of seam welds) ) → Expander (tapered) → Curl beader (curl and bead formation on the upper edge) → Flanger (flange formed on the lower edge) → Ground plate seamer → Ear welder → Lot application → Dry tester (leakage test) → Inner seam blowing Processing is performed in the order of attachment → velmatic (attachment of handle). However, in the ear welder, the handle mounting ears (ears) are welded to the upper position of the seam welded part and the radial facing position. Normally, the feed posture of the workpiece (cylindrical can body part) is the same as during seam welding. Since the horizontal direction of the workpiece is changed to the inverted state after the expander, and the direction of the rotation direction of the workpiece varies variously during each intermediate processing, the seam before each of the workpieces enters the ear welder. It is necessary to adjust the orientation so that the position of the welded part comes to the welded position of the ear part.

  Conventionally, the orientation of the workpiece before the ear welder is adjusted by the operator visually checking the seam welded part and manually correcting the workpiece orientation, or by touching the thickness change or level difference occurring in the seam welded part. In general, a method of detecting by the above contact method and mechanically rotating the workpiece based on the detected position to obtain a desired orientation has been adopted. As another method, the position of the seam welded portion is detected by a change in the reflected magnetic field when a low-frequency magnetic field is applied to the workpiece, and the workpiece is mechanically rotated based on the detected position to have a desired orientation. This has also been proposed (Patent Document 1).

Japanese Patent Laid-Open No. 9-300080

  However, in the conventional work orientation adjustment by the worker, in addition to poor efficiency by manual work, variations in the orientation are unavoidable, and the handle mounting accuracy is poor. In addition, the conventional means for detecting a seam weld by the contact method is liable to cause scratches on the workpiece surface due to the contact, and there is a concern that can quality and yield may be reduced, and false detection or non-detection due to vibration or the like occurs. There was a problem that the reliability of detection was inferior. On the other hand, the detection means based on the change of the reflected magnetic field has a very high radial equipment cost due to the detection device incorporating the magnetic field transmission mechanism, the reflected magnetic field reception mechanism, the signal processing mechanism, etc. Since the reflected magnetic field is likely to be disturbed due to the displacement of the workpiece and electromagnetic noise from peripheral devices, there is a problem in that the detection accuracy of the seam weld is inferior.

  Furthermore, in the can-making system based on the automatic line, there are various processes that require positioning of the workpiece during processing in addition to the ear welder. Depending on the type of workpiece to be processed and the process order, the seam welded portion is used as a positioning reference. In many cases, the conventional means for detecting a seam weld cannot be used for these processes.

  In view of the above-described circumstances, the present invention makes it easy to use a positioning standard that can be used in various processes without being affected by the type of work and the order of processes, by an automatic method with a low equipment cost burden in a can-making system using an automatic line. Another object of the present invention is to provide a means that can set the positioning reference accurately, easily and accurately without contact.

  If the means for achieving the above object is shown with reference numerals in the drawings, the can making system according to the invention of claim 1 is a can product (corner) through various processes continuously from a metal original plate or a processed product thereof. In the automatic line for manufacturing the can SC) or the can body 1 or the can lid (pail lug top plate 2B), the reference mark m is applied to the required position on the work surface with the fluorescent ink, and the required processing step downstream of the line or the A feature is that the workpiece is irradiated with ultraviolet light in front and the reference mark m is emitted and detected by the fluorescent sensors 7A to 7C, and the workpiece is positioned by the detected reference mark m to perform the required processing.

  According to a second aspect of the present invention, in the can making system of the first aspect, the fluorescent ink is substantially colorless and transparent.

  According to a third aspect of the present invention, in the can making system according to the first or second aspect, the reference mark m is applied by the ink jet printer 5.

  According to a fourth aspect of the present invention, in the can making system according to any one of the first to third aspects, the welding position of the handle mounting ear 13 in the can body 11 of the pail can PC is set by the reference mark m. .

  The invention according to claim 5 is the can making system according to any one of claims 1 to 3, wherein the formation position of the spout (base hole 27) in the can lid (pail lug top plate 2B) is set by the reference mark m. It is said.

  The invention of claim 6 is the can making system according to any one of claims 1 to 3, wherein the rectangular cylindrical body of the square can SC is formed by an expander from a cylindrical body obtained by seam welding both side edges of the plate. In this case, the bending position of the cylindrical body is set by the reference mark m.

  Next, effects of the present invention will be described with reference numerals in the drawings. First, according to the can manufacturing system according to the first aspect of the present invention, in the automatic line, the reference mark m is applied to the required position on the surface of the work (can body parts 11 and 31, pail lug top plate 2B) with fluorescent ink. The workpiece is irradiated with ultraviolet light before or at the required processing step on the downstream side of the line so that the reference mark m is emitted and detected by the fluorescence sensors 7A to 7C, and positioned by the detected reference mark m and required processing is performed. Therefore, the reference mark m can be detected in a non-contact manner without being affected by the type and process order of the workpiece, and there is no concern that the surface of the can is damaged. Moreover, since the fluorescent color is detected by the fluorescent sensors 7A to 7C, it can be easily and reliably captured even if the reference mark m is small, and the detection accuracy is affected even if various colored coatings are applied to the workpiece surface. In addition, the position accuracy of detection can be improved by reducing the reference mark m. Furthermore, there is an advantage that the equipment cost burden can be reduced because a spread type commercial product can be used as the means for applying the reference mark m, the fluorescence sensor, and the ultraviolet irradiation means without requiring special specifications for each.

  According to the invention of claim 2, since the fluorescent ink is substantially colorless and transparent, the reference mark m is substantially invisible to the naked eye, and there is no concern that the design and appearance of the can are impaired by the presence of the reference mark m.

  According to the invention of claim 3, since the reference mark m is applied by the ink jet printer 5, the reference mark m can be accurately and reliably displayed on the can surface with a small size.

  According to the invention of claim 4, the welding position of the handle mounting ear 13 can be set using the reference mark m for the pail can C1. For example, when the ear portion 13 is welded to the upper position of the seam welded portion s of the cylindrical can body portion 11 and the radially opposed position in the ear welder process of an automatic line as usual, the seam on the upstream side of the line is used. A reference mark m is applied to the welding process or immediately after the process in the radial direction, and the reference mark m is detected before entering the ear welder. Based on the detection position, the can body The portion 11 (can main body 1) is rotated, and the direction of the can body 11 may be adjusted so that the reference mark m and the seam welded portion s come to the welding position of the ear portion 13.

  According to invention of Claim 5, the formation position of the spout 23 can be set using the reference mark m for the can lid (pail lug top plate 2B). For example, a reference mark m is applied to a set base forming position on a metal plate before being punched into a round lid shape in a punching press process of an automatic line, or an original plate before being cut into the metal plate with a slitter, After each step of punching press, squeezing press, lining (gasket deposition), and drying, detect the reference mark m before drilling the die, and make sure that the reference mark m is at the drilling position. What is necessary is just to rotate a plate-shaped workpiece.

  According to the invention of claim 6, in the automatic line for manufacturing the rectangular can SC, the rectangular cylindrical body 31 of the rectangular can SC is obtained by bending the cylindrical body 30 obtained by seam welding the both side edges of the plate body with an expander. When the seam welding is performed, a reference mark m is applied to the cylindrical body 30 during or immediately after the seam welding at a specific distance from the seam welded portion s, and the reference mark m is detected before entering the expander. The position of the seam welded part s in the square can SC can be always set constant by adjusting the position of the cylindrical body based on the reference mark m and performing bending.

It is a perspective view which shows an example of the pail can to which the can making system of this invention is applied. It is a perspective view which shows an example of the pail lug top plate to which the can system is applied. It is a perspective view which shows an example of the square can to which the can manufacturing system is applied. It is a flowchart of the can manufacturing system which concerns on 1st embodiment of this invention. It is a model side view which shows the reference mark application process in the first embodiment. The application | coating situation in the same fiducial mark application | coating process is shown, (a) is a perspective view, (b) is a vertical front view. It is a schematic plan view which shows the rotation position adjustment process of the can main body in the first embodiment. The rotation operation of the can body in the same direction adjustment is shown, (a) is a cross-sectional plan view, (b) is a longitudinal side view. It is a flowchart of the can manufacturing system which concerns on 2nd embodiment of this invention. The setting state of the reference mark in the second embodiment is shown, (a) is a plan view showing a cut original plate to which a reference mark is applied, and (b) is a plan view of a pail lug top plate before the base is drilled. It is a flowchart of the can manufacturing system which concerns on 3rd embodiment of this invention. It is a top view which shows the bending process condition by the expander in the same 3rd embodiment.

  As a typical application object of the can making system of the present invention, a pail can PC of FIG. 1, a pail lug top plate 2B of FIG. 2, and a square can SC of FIG. 3 are illustrated.

  First, in the pail can PC shown in FIG. 1, a steel can body 1 is composed of a substantially cylindrical can body portion 11 and a disk-shaped ground plate 12 constituting the bottom of the can. The steel crown-shaped handle mounting ears 13 are welded to both sides in the radial direction, and an arc-shaped handle 14 made of a thick wire is engaged with both ends so as to be rotatable up and down via both ears 13 and 13. In addition, a lug top plate 2A is detachably fitted to the upper end opening of the can body 1 through a peripheral lug 21-. The can body 11 of the can body 1 is formed by bending a metal flat plate into a circular shape and performing seam welding. One ear portion 13 is located on the seam welded portion s and outward on the upper side. It has two upper and lower annular beads 11a, 11b that bulge, and the lower part of the lower bead 11b is slightly tapered downward as a taper pail can.

FIG. 4 shows a flow chart of an automatic line for manufacturing the can body 1, and the contents of each process are as follows.
Sheet feeder: A substantially square original plate (steel plate) is supplied to the conveyance line.
Slitter: Cut the original plate in half to make two strips.
Cylindrical forming ... Each strip is bent into a circle.
Seam welding ··· Weld both ends of the bent strip to make a cylindrical can body.
Clear coating: Apply rust prevention coating on the outer surface of the seam weld.
Expander: Expands the inner diameter of the can body to form a pail can.
Curl beader: curls the outer edge of the upper edge outward and forms a bead.
Flanger: An outward flange is formed around the lower edge.
Base plate seamer: A base plate manufactured in a separate line is fixed to the lower end of the can body.
Ear welder: Weld the handle mounting ears on both sides of the can body in the radial direction.
Lot marking ················································· Display the display item including the lot number.
Dry tester: Check for leaks by blowing air.
Inner surface seam spraying: Rust prevention coating on the inner surface of the seam weld.
Velomatic: Complete the can body by attaching the handle to the handle mounting ear.

  In the first embodiment of the can manufacturing system of the present invention, in the automatic line for manufacturing the can body 1, a fiducial mark application process is interposed between the seam welding process and the clear coating process, and an ear welder process is performed. A rotational position adjustment process is added to the front.

  As shown in FIG. 5, the reference mark application process includes an inkjet printer 5 installed in a conveyance path 4 in which the can body 11 as a workpiece is conveyed in a sideways state during seam welding, and the printer A transmission sensor 6 is arranged on the side in front of the head 5b, and a controller 60 for controlling the operation of the ink jet printer 5 based on a detection signal from the transmission sensor 6 is installed at a lower position. The printer head 5 b is disposed immediately above the can body 11 that passes through a gate-shaped head mounting frame 51 that straddles the conveyance path 4. 5c is an ink tube for feeding fluorescent ink from the lower printer body 5a to the printer head 5b, 52 is a tube support frame for supporting the ink tube 5c, and 53 is a signal lamp for displaying the processing status.

  In the reference mark application process, when the can body 11 conveyed from the seam welding process passes the position of the transmission sensor 6, a detection signal is output from the transmission sensor 6, and the controller 60 is based on the detection signal. Accordingly, an operation signal of the jet printer 5 is issued, and the reference mark m is applied to a predetermined position on the top of the can body 11 by the fluorescent ink ejected from the printer head 5b. Thus, as shown in FIGS. 6A and 6B, the seam welded portion s of the can body portion 11 conveyed in a lateral direction from the seam welding process via the conveying roller 4a of the conveying path 4 has the lowest portion. Therefore, the reference mark m applied to the top portion of the seam weld portion s faces the seam weld portion s in the radial direction. The applied reference mark m becomes a substantially invisible hidden mark with the naked eye by using a substantially colorless and transparent fluorescent ink.

  On the other hand, in the rotational position adjustment process, the can main body 1 is conveyed from the main plate seamer process in an inverted state with the main plate 12 side, that is, the bottom side up. First, in the primary adjustment portion P1 shown in FIG. The can body 1 is lifted from the conveyance path 4, and the can body 1 is rotated to one side in the circumferential direction (arrow a direction) in this lifted state, and the can body 1 is provided by the fluorescence sensors 7A and 7B including the ultraviolet light projecting section and the fluorescence light receiving section. A reference mark m that emits fluorescence is detected by projecting ultraviolet rays onto the outer peripheral surface of the lens. And, if the reference mark m comes to the rear end position in the radial direction along the conveying direction O as shown in the figure, by continuing to rotate the can body 1 by a specified angle from the direction at the time of detection and stopping it, of course, Further, the seam welded portion s of the can body 1 is at the front end position in the same radial direction.

  In the example of FIG. 7, the light projecting / receiving shafts 71 and 72 of both fluorescent sensors 7A and 7B of the primary adjustment unit P1 are both oriented toward the axis of the can body 1, but the rotation direction a of the can body 1 is used as a reference. The angle α of the fluorescent sensor 7A with respect to the conveying direction O of the light projecting / receiving shaft 71 is set to 50 °, and the light transmitting / receiving shaft 72 of the fluorescent sensor 7B is set to 130 °. In this case, if the reference mark m of the can body 1 that has reached the primary adjustment portion P1 is at the position of m1 shown in the drawing, for example, the fluorescence sensor 7A detects the rotation of the can body 1 first. The can body 1 is rotated by 130 ° and stopped, so that the reference mark m comes to the radial rear end position along the transport direction O. Similarly, if the reference mark m of the reached can body 1 is at, for example, the position of m2 shown in the drawing, it is detected by the fluorescent sensor 7B first. Accordingly, the reference mark m is similarly positioned at the radial rear end position.

  Even if the can body 1 is stopped by rotation of 50 ° from the detection by the fluorescent sensor 7B, the reference mark m should be at the rear end position in the radial direction as well, but the rotation amount until the stop is too small. Since it suddenly stops, the stop position is easily shifted by inertial force. Further, even if only one fluorescent sensor of the primary adjustment unit P1 is used, the detection of the reference mark m and the rotational position adjustment can be performed in the same manner. For example, when only the fluorescent sensor 7A is used, the reference mark m of the reached can body 1 is m2. If it is a position, the can main body 1 needs to make approximately one rotation before the detection, so that it takes time to adjust the rotation position and the production efficiency of the automatic line is lowered. Therefore, it is desirable to arrange the two fluorescent sensors 7A and 7B from the viewpoint of production efficiency, but in the example, both fluorescent sensors 7A and 7B are arranged with a phase difference of 80 ° to reach the primary adjustment unit P1. This is because the positional fluctuation of the reference mark m of the can main body 1 is normally within an angular range of ± several tens of degrees of the light projecting / receiving shaft 70 of the fluorescent sensor 7A. Of course, if the position variation of the reference mark m is large, the phase difference of both fluorescent sensors 7A and 7B may be increased accordingly, and if the reference mark m varies over the entire circumference, both fluorescent sensors 7A and 7B. Is recommended to be placed on both sides in the radial direction (180 ° phase difference).

  In the rotational position adjustment process illustrated in FIG. 7, the can main body 1 whose rotational position is adjusted by the primary adjustment part P1 is further rotated approximately 1/4 by the secondary adjustment part P2, thereby processing in the next ear welder process. The orientation is set to the orientation (ear welding from both sides in the width direction of the conveyance path 4). And in this secondary adjustment part P2, the can main body 1 is rotated in the circumferential direction one side (arrow a direction) in the state where it lifted from the conveyance path 4 similarly to the primary adjustment part P1. The fluorescent sensor 7C having a light receiving unit detects the reference mark m that is emitted by projecting ultraviolet rays onto the outer peripheral surface of the can body 1, and continues to rotate the can body 1 by a specified angle from the direction of detection and stops. By doing so, the fine adjustment is made so that the reference mark m and the seam welded portion s are precisely located on both sides in the radial direction along the width direction Q of the conveyance path 4. That is, the direction of the can body 1 may change slightly while moving from the primary adjustment section P1 to the secondary adjustment section P2. Therefore, the secondary adjustment section P2 simply rotates the can body 1 by 90 °. Rather, this rotational operation corrects the change in orientation accompanying the movement.

  Thus, the light projecting / receiving shaft 73 of the fluorescent sensor 7C in the secondary adjustment section P2 is oriented at the axis of the can body 1 at an angle γ of −20 ° with respect to the width direction Q of the transport path 4 and can rotate at a low speed. When one reference mark m is detected, the can body 1 is stopped by rotation of 20 ° from the time of detection, so that the reference mark m and the seam welded portion s are precisely in the radial direction along the width direction Q of the conveyance path 4. I try to come to both sides. In addition, since rotation of the can main body 1 in this secondary adjustment part P2 is set to low speed, even if the rotation amount until a stop is small, high stop position accuracy can be ensured. Thus, the can body 1 whose direction is precisely set by the secondary adjustment unit P2 is chucked in the rotational posture and carried into the ear welder process.

  As shown in FIGS. 8 (a) and 8 (b), the rotating operation of the can main body 1 in the primary and secondary adjusting portions P1 and P2 of the rotational position adjusting process is performed by first moving the can main body 1 carried in an upside down state. A plurality of (four in the figure) circumferentially rotatable lifting cones 81 arranged in the vertical direction are lifted by supporting and lifting the upper peripheral edge 11c (arranged at the lower end by handstand) by the flange portions 81a of the lifting cones 81. . And the outer peripheral part between the upper end peripheral edge 11c of the can body 1 in the lifted state and the upper bead 11a is sandwiched between the driving roller 82 and the backup roller 83 from both sides in the radial direction, and the lifting type disposed above. The can presser 9 is lowered, and a plurality (four in the figure) of idle rollers 91 attached to the lower surface side of the base plate 90 in the circumferential direction are attached to the lower end of the can main body 1 (the upper end is turned upside down). In this state, the drive roller 82 is rotationally driven to rotate the can body 1. Then, when the reference mark m of the can body 1 is detected by the fluorescent sensors 7A to 7C, the driving roller 82 has a predetermined rotation amount for each of the fluorescent sensors 7A to 7C from the detection point through a control device (not shown). Stop. In addition, the can body 1 is in a stable rotation state from the start to the stop of the rotation, by preventing the core swing from being caused by the elevating cone 81 and by preventing the upper can lift 9 from jumping upward. Retained.

  In the first embodiment described above, in the automatic line for producing the can body 1 of the pail can PC, the feeding posture of the can body 1 (can body portion 11) is changed from a lateral state during seam welding to an inverted state after the expander. In addition, although the direction of the rotation direction varies and is not constant during each intermediate processing, the rotational position of the can body 1 can be precisely adjusted using the reference mark m before entering the ear welder. In the ear welder, the handle mounting ear 13 can be accurately welded to the seam welded portion s and the radially opposed position thereof, so that the can body 1 having no variation in the handle mounting position can be stably provided. Further, since the reference mark m can be detected without contact, there is no fear of scratching the surface of the can, and since the fluorescent color is detected by the fluorescence sensors 7A to 7C, the reference mark m is surely easily even if the reference mark m is small. It can be captured and there is no decrease in detection accuracy due to various colored coatings usually applied to the surface of the can body 11, and the reference mark m can be accurately and reliably expressed in a small size by the ink jet printer 5. The position accuracy of detection can be further increased.

  The pail lug top plate 2B shown in FIG. 2 is detachable from the upper end opening of the can body 1 (see FIG. 1) via a peripheral lug 22- like the pail lug top plate 2A used in the pail can PC of FIG. The cap 23 and the spout 23 with the tongue 24 are provided. FIG. 9 shows a flowchart of an automatic line for manufacturing the pail lug top plate 2B. The contents of each process are as follows.

Sheet feeder: A substantially square original plate (steel plate) is supplied to the conveyance line.
Slitter: Cut the original plate in half to make two strips.
Punching press ... Punches two original rugged top plates from each strip.
Drawing press: Bends the peripheral edge of each original shape of the top plate to raise the lug, and forms an annular protrusion for reinforcement along the periphery.
Lining: Apply gasket material to the inner surface of the bent peripheral edge.
Dryer: foaming and curing the gasket material.
Die hole punching ... A hole for a die is punched and formed.
Clamping the base .... Attach the base to the hole for the base and fix it by crimping.
Velo mounting ... Install a bellow for pouring into the base of the hole for the base.
Cap tightening ··· Attach the cap to the base of the base hole and tighten.
Leak test .... Check for leaks in the hole for the cap.

  In the second embodiment of the can making system of the present invention, in the automatic line for producing the pail lug top plate 2B, a reference mark application process is interposed between the slitter process and the punching press process, and the hole for the die is formed. A rotational position adjustment step is added before the step. That is, as shown in FIG. 10 (a), from the strip plate 25 that has undergone the slitting process, two top plate prototypes 20 with lugs are punched out as shown by the broken lines in the punching press process. A reference mark m is applied in advance to the formation position of the hole for the die with fluorescent ink. Then, in the rotational position adjustment step before the base hole punching step, the rotational position of the top plate 26 conveyed from the dryer is used as the base mark 27 in the base base hole step 27 in the next base hole drilling step (illustrated virtual). The top plate 26 is chucked at this adjusted rotational position and conveyed to the die opening process.

  Thus, the reference mark m may be applied automatically using an ink jet printer as in the first embodiment. In addition, for the detection of the reference mark m in the rotational position adjustment step and the rotational position adjustment of the top plate 26 based on this detection position, the top plate 26 is rotated by an appropriate rotation mechanism as in the first embodiment. By detecting the fluorescence emission of the reference mark m with the fluorescence sensor and stopping the top plate 26 with a predetermined amount of rotation from the detection, the reference mark m may be set so as to come to the position where the base hole 27 is formed. . In this case, the number of fluorescent sensors, the installation position, and the number of rotation position adjustment stages can be set as appropriate according to the difficulty level of rotation stop and the automatic line apparatus configuration.

  The rectangular can SC shown in FIG. 3 has a substantially rectangular top plate 32 and a base plate 33 fixed to the upper and lower ends of a can body 31 having a substantially rectangular cross section, and the top plate 32 is provided with a handle 34 and a cap 36. An outlet 35 is provided. And the can body part 31 has the seam weld part s along a vertical direction in the position which entered into the side surface 31b side a little from the boundary part of the main surface 31a and the side surface 31b. FIG. 11 shows a flowchart of an automatic line for manufacturing this square can SC. The contents of each process are as follows.

Sheet feeder: A substantially square original plate (steel plate) is supplied to the conveyance line.
Slitter: Cut the original plate into 6-8 strips.
Cylindrical forming ... Each strip is bent into a circle.
Seam welding ··· Weld both ends of the bent strip to make a cylinder.
Expander: The cylinder is pushed out from the inside to form a square cylindrical can body.
Frenzy ... Expands the opening edge of both ends of the can body to the outside.
Base plate seamer: A base plate manufactured in a separate line is fixed to the lower end of the can body.
Lot marking ················································· Display the display item including the lot number.
Top plate seamer: A top plate manufactured on a separate line is fixed to the upper end of the can body.
Dry tester: Check for leaks by blowing air.

  In the third embodiment of the can making system of the present invention, in the automatic line for manufacturing the square can SC, a reference mark applying step and a rotational position adjusting step are added before and after the seam welding step and the expander step. . That is, in the fiducial mark application step, as shown by the phantom line in FIG. 12, the fiducial mark m is applied to the cylinder 30 obtained through seam welding at a position facing the seam weld s in the radial direction. Keep it. Then, in the next rotational position adjustment step, while the cylinder 30 is rotated, the fluorescence emission of the reference mark m is detected by the fluorescence sensor, and the cylinder 30 is stopped at a predetermined rotation amount from the detection time, thereby the seam. The welded portion s is adjusted in a bending process in the next expander process so that the welded portion s slightly enters the side surface 31b from the boundary between the main surface 31a and the side surface 31b as shown in the solid line in the drawing, and the cylinder is moved to the adjusted rotational position. 30 is chucked and conveyed to the expander process.

  The application of the reference mark m in the reference mark application process may be automatically performed using an ink jet printer in the same manner as in the first embodiment. The same rotation mechanism as in the first embodiment can also be adopted for the detection of the reference mark m in the rotation position adjustment step and the rotation position adjustment of the cylinder 30 based on this detection position.

  According to the can manufacturing system of the second embodiment, in the production of the pail lug top plate 2B by an automatic line, a high-quality product in which the mouthpiece hole 27 is always in an appropriate fixed position can be stably mass-produced. In addition, according to the can manufacturing system of the third embodiment, high-quality products in which the seam welded part s of the can body 31 is in an appropriate fixed position can be stably mass-produced in the production of the square can SC by an automatic line. it can.

  The fluorescent ink used for application of the reference mark m is not particularly limited, but the reference mark m is substantially invisible to the naked eye so that the design and appearance of the can are not impaired by the presence of the reference mark m. A substantially colorless and transparent material is preferable. The substantially colorless and transparent includes completely colorless and transparent as well as transparent having a very light hue such as yellowish transparency. Commercially available fluorescent inks for inkjet printers include trade name CN9 invisible ink (fluorescence wavelength 450 nm) manufactured by Kishu Giken Kogyo Co., Ltd., trade name LINX-UV invisible ink 3160 (fluorescence wavelength 385 nm) manufactured by Union Corporation, Hitachi, Ltd. Examples include trade name JPS-92 (fluorescence wavelength 565 nm) manufactured by Sanki System Co., Ltd.

  The ultraviolet light that causes the reference mark m to emit fluorescence may be any wavelength / intensity that has the energy to excite and emit the phosphor, but near ultraviolet light having a wavelength of about 300 to 400 nm that is not harmful to human eyes is particularly suitable. It is. Irradiation of the reference mark m with ultraviolet rays may be performed by various ultraviolet lamps such as black light in addition to the ultraviolet light projecting unit of the fluorescent sensor itself as in the embodiment. In addition, the fluorescence sensor for detecting the fluorescence emission of the reference mark m may be any sensor having sufficient detection sensitivity in the wavelength range according to the fluorescence wavelength of the fluorescent ink used. In some cases, a visible light sensor may be used, and in the case of only the ultraviolet region, an ultraviolet sensor may be used.

  In the first to third embodiments described above, the automatic line can manufacturing system for the pail can PC, the pail lug top plate 2B, and the square can SC is illustrated, but the can manufacturing system of the present invention can be used in various other ways. It can be applied to the case where it is necessary to detect a specific part of a workpiece as a positioning reference when positioning a workpiece in various processes on the line in an automatic line for producing a can product, a can body and a can lid in a metal can. . In the first to third embodiments, the reference mark m for a single machining is set. However, in order to set the positioning reference for a plurality of types of machining on the same automatic line, the reference mark m is set at a plurality of locations on the workpiece. It is also possible to provide a reference mark m corresponding to each processing. Furthermore, the setting position of the reference mark m only needs to be a positioning reference of the workpiece at the time of processing, and does not need to match the processing position as in the first and second embodiments, and is limited by the shape of the workpiece and the surface design, It can be set as appropriate according to restrictions on the installation position of the coating head and fluorescent sensor in the automatic line.

1 Can body (work)
11 Can body (work)
13 Handle mounting ear 14 Handle 2B Pail lug top (can lid, workpiece)
26 Band plate (metal plate)
27 Hole for base (outlet)
30 cylinder (work)
31 Can body (work)
5 Inkjet printer 7A-7C Fluorescence sensor PC Pail can SC Square can m Reference mark s Seam weld

Claims (6)

  In an automatic line for manufacturing can products or can bodies or can lids through various processes continuously from the original metal plate or its processed material, a reference mark is applied to the required position on the work surface with fluorescent ink, and the downstream side of the line is required. A can-making system characterized in that a reference mark is emitted by irradiating a work piece with ultraviolet light before or in front of the processing step, the reference mark is emitted and detected by a fluorescence sensor, and the required processing is performed by positioning with the detected reference mark .   The can manufacturing system according to claim 1, wherein the fluorescent ink is substantially colorless and transparent.   The can-making system according to claim 1 or 2, wherein the reference mark is applied by an inkjet printer.   The can manufacturing system according to any one of claims 1 to 3, wherein a welding position of a handle mounting ear in a can body of a pail can is set by the reference mark.   The can making system according to any one of claims 1 to 3, wherein a position for forming a spout in the can lid is set by the reference mark.   The bending position of the cylindrical body according to any one of claims 1 to 3, wherein when the square cylindrical body of the square can is formed by an expander from a cylindrical body obtained by seam welding both side edges of the plate body, the bending position of the cylindrical body is set by the reference mark. The can-making system described in 1.

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