JP5882173B2 - Drum can printing drying apparatus and drum can printing drying method - Google Patents

Description

The present invention relates to a drum can printing drying apparatus and a drum can printing drying method for drying ink printed on a drum can conveyed on a roller conveyor.

Conventionally, when the object to be coated is a magnetic metal product, in order to dry the coating film coated on the outer peripheral surface of the object, the object to be coated is heated by high frequency induction and the surface paint is transferred by heat transfer from the object to be coated. There is known a technique for drying in a short time.
In the case of a compressor that is an object to be coated, the compressor is suspended and transported by an overhead conveyor and stored in a drying furnace by a work transfer device, and then the high-frequency induction heating device is operated to dry the compressor. An apparatus and a method are disclosed (for example, see Patent Document 1).

Further, in Patent Document 2, a disk rotor (object to be coated) is conveyed by a roller conveyor, and after the surface to be painted is painted by a painting robot, a high frequency induction heating coil for drying and heating is passed through a setting process for curing. A technique for heating the film and drying the coating film is disclosed.
In detail, after the disk rotor is painted by the painting robot, it is transported under the high-frequency induction heating coil for drying downstream by the operation of the roller conveyor, the conveyance is stopped by the corresponding stopper, and high-frequency induction for drying is performed. It is lifted by a cylinder provided below the roller conveyor facing the heating coil and the roller conveyor, and the painted surface of the disk rotor is inserted into the coil body of the high-frequency induction heating coil for drying and heated to, for example, 140 ° C. (The temperature rising time is, for example, 1 minute, and the drying time is, for example, 30 seconds) The coating film is dried.

JP-A-8-332434 JP 2006-130384 A

Since the drying of the compressor described in Patent Document 1 needs to dry the entire outer peripheral surface of the compressor, the compressor is dried in a tunnel drying furnace. However, if this method is used to dry only a part of the peripheral surface of the object to be heated, a drying furnace is required, the overall equipment area is increased, and parts that do not need to be dried are also heated. Is wasted.

In the case of the disc rotor (object to be coated) described in Patent Document 2, the object to be coated is dried over a relatively long time (here, about 30 seconds) on the production line. As described above, when the production tact time is slow, it is not necessary to consider the inertial force of the object to be coated when the object is stopped during conveyance or sent to the next process.
However, when producing drums that are larger than this disk rotor and are heavy (up to 30 kg in weight), the production speed of the production line is 5 to 7 seconds. Inertia force becomes a problem, and the technology that stops the object to be dried accurately and quickly during transportation, stabilizes the object to be sent to the next process quickly after drying, and conveys it on the roller conveyor. Needed.

In the present invention, when drying ink printed on a drum can conveyed on a roller conveyor, the drum can is quickly stopped in accordance with the speed of the drum can production line without using a tunnel drying furnace. Provided is a drum can printing drying apparatus and a drum can printing drying method in which only the printing surface is dried in a short time (1.5 to 3 seconds), and then the operation of conveying to the next process is completed in a predetermined time (4 to 6 seconds). For the purpose.

A drum can printing and drying apparatus according to the first invention that meets the above-mentioned object is a roller conveyor that conveys a drum printed on a printing surface from upstream to downstream;
A centering unit that is in the middle of the roller conveyor, adjusts the position in the width direction of the drum can relative to the roller conveyor, and elastically supports the upper portion of the drum can immediately before the stop position of the drum can;
A stopper for stopping the drum can by protruding from a gap between the rollers at a predetermined position of the roller conveyor, contacting the lower portion of the drum can conveyed by the roller conveyor,
And an induction heating unit that dries the printing surface at a predetermined angular position with respect to the conveying direction of the roller conveyor of the drum can stopped by the stopper.

In the drum printing apparatus according to the first aspect of the invention, the induction heating unit is attached to one side (for example, a part other than the base) of the arm that has a base that is the center of horizontal rotation outside the roller conveyor. Is preferred.

In the drum can printing and drying apparatus according to the first aspect of the invention, the induction heating unit is connected to a high-frequency power source fixedly arranged via a cable, and the cable is fixed to the arm, and the fixed wiring portion is fixed to the arm. It is preferable that the wiring portion and the free wiring portion are wired with a vertical or near vertical inclination connecting the high-frequency power source, and the torsion of the cable is absorbed by the free wiring portion by the rotation of the arm.

In the drum can printing and drying apparatus according to the first aspect of the present invention, it is preferable that the induction heating unit has a concave surface along the drum can and includes a roller guide for positioning the induction heating unit and the drum can.

In the drum printing apparatus according to the first aspect of the present invention, the induction heating unit includes a heating coil and a coil support portion made of a nonmagnetic metal that supports the heating coil and has the concave surface, and a rear side of the coil support portion. It is preferable to have a plurality of vent holes.

In the drum can printing drying method according to the second invention, the drum can printed on the printing surface at a predetermined angular position on the outer periphery is conveyed from upstream to downstream via a roller conveyor, stopped at a specific position of the roller conveyor, A drum can printing method for drying a printing surface,
The drum can transported by the roller conveyor at a position before the specific position of the roller conveyor is elastically sandwiched between pairs of support rollers from both sides in the width direction of the roller conveyor, and the width direction of the drum can with respect to the roller conveyor A first step of adjusting the position and supporting the upper portion of the drum just before the stop position of the drum,
A second step of causing a stopper to protrude from a gap between the rollers on the roller conveyor, and stopping the drum can conveyed at the roller conveyor at a specific position;
A third step of closely arranging an induction heating unit having a concave surface having a gap of a certain distance from the drum can on the printing surface of the drum;
A fourth step of supplying high-frequency power to the induction heating unit from a high-frequency power source for a predetermined time;
And a fifth step of retracting the induction heating unit and releasing the stopper and transporting the drum can by the roller conveyor.

The drum can printing and drying apparatus according to the present invention uses the centering unit to adjust the position in the width direction by elastically supporting the upper portion of the drum can immediately before being stopped by the stopper, and on the roller conveyor. The speed of the drum can is gradually reduced, and the fall due to the inertial force when stopped by pressing the upper end can be prevented. Further, the drum can on the roller conveyor can be stopped at an accurate position and quickly. As a result, since it always stops at an accurate position, the induction heating unit can be quickly dried with optimum power by configuring the induction heating unit with a size that matches the printing surface of the drum.

In particular, in the drum can printing and drying apparatus according to the present invention, when the induction heating unit is attached to one side of the arm having the base that is the center of horizontal rotation outside the roller conveyor, the rotation operation about the axis is performed. Therefore, it is possible to perform the drying operation by quickly approaching and storing. Therefore, drying and retreating operations can be performed on the drum can production line in accordance with the drum can transport speed.

In the drum can printing and drying apparatus according to the present invention, when the free wiring portion of the cable is wired with a vertical or nearly vertical inclination connecting the high frequency power supply, the twist of the cable due to the pivoting operation of the arm is reduced, The life of the cable can be extended.

In the drum can print drying apparatus according to the present invention, when the induction heating unit has a concave surface along the drum can and includes a roller guide for positioning the induction heating unit and the drum can, an appropriate gap is always ensured from the print surface of the drum can. As a result, excessive heating of the printing surface can be prevented.

In the drum can print drying apparatus according to the present invention, the induction heating unit includes a heating coil and a coil support portion made of a non-magnetic metal that supports the heating coil and has a concave surface, and a plurality of ventilation holes are provided on the rear side of the coil support portion. When it has, since the coil support part is not induction-heated and the air whose temperature has increased in the vicinity of the heating coil can be efficiently exhausted, the temperature increase of the heating coil can be suppressed.

In the drum can printing and drying method according to the present invention, the speed of the drum can on the roller conveyor is gradually reduced by sandwiching the upper portion of the drum can with a pair of support rollers before stopping at the stopper, and the upper portion of the drum can be pressed. Therefore, it is possible to prevent a fall due to the inertial force when stopped. Immediately after supporting the top of the drum can, the drum can is stopped on the roller conveyor by the stopper, so that it can be stably stopped, and the induction heating unit is arranged near the printing surface on the outer periphery of the drum can. Can be dried quickly with less energy.

It is explanatory drawing which planarly viewed the drum can printing drying apparatus which concerns on one embodiment of this invention. It is explanatory drawing which looked at the drum can printing drying apparatus from the side. It is an arrow AA figure in FIG. It is explanatory drawing which looked at the main body of the drum printing printing apparatus from the front. It is explanatory drawing which planarly viewed the centering unit. It is explanatory drawing which planarly viewed the drying unit. It is explanatory drawing which looked at the drying unit from the front. It is an arrow BB figure in FIG. It is explanatory drawing which shows the standby state of an induction heating unit. It is explanatory drawing which shows the state which the same induction heating unit dries the drum.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 to 3, the drum print drying apparatus 10 according to an embodiment of the present invention includes a roller conveyor 12 that conveys a drum can 50 printed on a printing surface 51 from upstream to downstream, and a roller conveyor 12. The centering unit 20 that adjusts the position in the width direction of the drum can 50 with respect to the roller conveyor 12 and elastically supports the upper portion of the drum can 50 immediately before the stop position of the drum can 50, and a predetermined position of the roller conveyor 12 The stoppers 14a and 14b that protrude from the gaps between the rollers 15 and contact the lower portion of the drum can 50 conveyed by the roller conveyor 12 to stop the drum can 50, and advance and retract in the width direction with respect to the roller conveyor 12, The drum can 50 stopped at 14a and 14b at a predetermined angular position with respect to the conveying direction of the roller conveyor 12. The printing surface 51 in having an induction heating unit 33 for drying. Details will be described below.

In the production line of the drum can 50, the drum can 50 is made from the upstream side in the conveying direction, and is sent to the upstream side of the belt conveyor 11 in a state where the entire coating is completed. The belt conveyor 11 is provided on the upstream side of the roller conveyor 12, and rotates the belt 19 provided on the upper side to convey the drum can 50 (diameter of about 585 mm) from the upstream side to the downstream side. The drive unit 11a is provided in the lower part of the. In addition, two printing units (PC coders) 16 and 16 a are provided side by side on the belt conveyor 11 in order to print the product number and the like on the printing surface 51 at the lower outer peripheral surface of the drum can 50.

The printing unit 16 prints a product number or the like on the printing surface 51 by a transfer method in which the printing roll 26 with ink is contacted and rotated on the outer peripheral surface of the drum can 50 being conveyed. Therefore, since the force of the stamping roll 26 is applied to the outer peripheral surface of the drum can 50, the belt 19 having a large frictional force on the surface in contact with the bottom surface of the drum can 50 is used so that the position of the drum can 50 does not shift. The predetermined angular position θ of the print surface 51 with respect to the conveyance direction of the drum can 50 is within a range of 115 degrees from θ1 to θ2 (θ1 = 45 degrees, θ2 = 150 degrees).
Here, the printing method uses a transfer method, but there is no particular limitation, and an ink jet method may be used. Further, instead of the belt 19, a magnet roller containing a magnet may be used.
In addition, the second printing unit 16a arranged in the transport direction with the printing unit 16 prints a color different from that of the first printing unit, or performs ink replacement setup before ink runs out. It may be provided for alternate use.

Next, the drum can 50 printed by the printing unit 16 is sent to the roller conveyor 12 on the downstream side in the transport direction. The roller conveyor 12 includes a drive unit 12a in the lower part on the upstream side in the transport direction, and rotates a number of rollers 15 provided on the upper part to sequentially transport the drums 50 placed on the rollers 15 to the downstream side in the transport direction. To do. Further, stopper units 13 and 14 are provided on a part of the lower side of the roller 15 to stop the drum can 50. The stopper unit 14 is provided to stop the drum can 50 at a position where it is dried. The stopper unit 13 is provided at a standby position of the drum can 50 to be sent to the drying position next, and sequentially transports the drum can 50 one by one to the position where the drum can 50 is dried.

Each of the stopper units 13 and 14 includes a pair of stoppers 13a and 13b and a pair of stoppers 14a and 14b. The stoppers 13a, 13b, 14a, and 14b are protruded from the rollers 15 of the roller conveyor 12 so that the drum 50 The drum can 50 is stopped against the lower outer peripheral surface 57 (for example, the lower chime). For example, the stoppers 14a and 14b are moved up and down by the expansion and contraction of the stopper cylinder 22 to stop or release the drum can 50. That is, this position is a stop position of the drum can 50.

A drum print drying apparatus main body 17 is provided on the side of the roller conveyor 12. The drum can printing and drying apparatus main body 17 includes a centering unit 20 for correcting the position of the drum can 50 and a drying unit 27. Further, the centering unit 20 is provided so as to protrude upward from the side of the roller conveyor 12. The centering unit 20 has a pair of support rollers 18 and 18a. The support roller 18 and the support roller 18a sandwich the upper outer peripheral surface 56 (for example, the upper chime) of the drum can 50, so that the shaft center of the drum can 50 is a roller. The drum can 50 is moved so as to coincide with the center position of 15 axial centers (here, the center position of the centering unit 20).

Further, when the drum can 50 is stopped by abutting the stoppers 14a and 14b against the drum can 50, the drying unit 27 rotates the induction heating unit 33 around the rotating shaft 31 in the drying unit 27, and the drum can This is because the print surface 51 is inductively heated and dried close to the 50 print surfaces 51.

As shown in FIGS. 3, 4, and 7, the drum print drying apparatus main body 17 is provided so that a drying unit 27 having a fixed frame 28 is placed on the mount 40 and further covers the fixed frame 28. A control unit 25 is provided on the upper surface of a U-shaped case 47 whose front and back surfaces are open. The control unit 25 includes a high-frequency power supply 44 that supplies power for induction heating and a control unit (not shown) that controls the front and rear cylinders 49 of the drying unit 27.
The control unit 25 may be configured such that the arrangement of the drying unit 25 is reversed and the control unit 25 is arranged on the lower side.

Further, the gantry 40 is necessary to match the heights of the roller conveyor 12 and the drying unit 27, and the control unit 25 can be placed on the upper surface of the drying unit 27 even if the installation space is small. It becomes possible. The gantry 40 is composed of four column members erected on a rectangular bottom in plan view, a long beam member that connects each column member at the top and bottom, and a short beam member, A rectangular top plate is arranged.

A centering unit 20 is attached to the drum printing and drying apparatus main body 17 via an attachment 54 (see FIG. 5). Further, the centering unit 20 and the stoppers 14a and 14b are positioned so that the drum can 50 comes into contact with the stoppers 14a and 14b immediately after the support rollers 18 and 18a of the centering unit 20 sandwich the upper outer peripheral surface 56 of the drum can 50. Has been placed. By doing in this way, there exists an effect | action which moves the drum can 50 so that it may correspond to the position of the axial center center of the roller 15, and decelerates the collision speed at the time of the drum can 50 colliding with stopper 14a, 14b. As a result, since the upper outer peripheral surface 56 of the drum can 50 is elastically supported, there is an effect of preventing the drum can 50 from being overturned at the time of collision and reducing the bounce at the time of the collision of the drum can 50 and the accompanying loss of the time of overturning. .

In addition, the bottom surface of the high frequency power supply 44 fixedly arranged in the control unit 25 placed on the upper surface of the case 47 and the induction heating unit 33 in the drying unit 27 are connected via a cable 45. This is because the high-frequency power is supplied from the high-frequency power supply 44 to the induction heating unit 33 by the cable 45 to control the energization of the heating coil 39. Here, the cable 45 uses a pair of litz wires 55 and the like coated with insulation. This is because the litz wire 55 has an effect of suppressing an increase in electrical resistance due to the skin effect.
The cable 45 may be a pair of litz wires arranged in parallel. However, it is desirable to wire the cable 45 as a stranded wire in order to cancel the generated electric field and not to heat the cable 45 and the surroundings.

The cable 45 is wired to the cable support member 46 with a fixed wiring portion 60 fixed via a cable fixing tool 52 and a vertical or nearly vertical inclination connecting the fixed wiring portion 60 and the high-frequency power supply 44. It consists of part 61. That is, as shown in FIG. 8, the free wiring portion 61 of the cable 45 is wired along the rotation axis 53 on the axis of the rotation shaft 31 of the induction heating unit 33. The cable support member 46 is fixedly attached to the arm 35 to which the induction heating unit 33 is attached.
This is because the induction heating unit 33 operates so as to be rotatable about the rotation shaft 31 of the arm 35, so that the twist of the cable 45 is freely wired in order to prevent the twisting force of the rotation operation from being applied as much as possible. Absorbed by part 61. By doing so, the induction heating unit 33 can reduce the twisting force and the twisting length applied to the cable 45 even if the rotating operation is repeated at intervals of several seconds. As a result, the durability of the cable 45 is maintained even in repeated operations of 1 million times / year or more.

As shown in FIGS. 3 and 5, the centering unit 20 is placed on a fixture 54 provided so as to protrude from the case 47 in the direction of the roller conveyor 12. The centering unit 20 has a base member 41 that is passed at right angles to the beam member 42 at an intermediate portion of the upper surface of the beam member 42 that is a part of the structure of the fixture 54, and both end portions of the base member 41. The brackets 29 and 29a and the brackets 59 and 59a are connected to the base member 41 through the pins 24f and 24g, respectively. And can be rotated freely. The same applies to the bracket 29a and the bracket 59a.

Further, support rollers 18 and 18a are connected to the other ends of the brackets 29 and 29a via pins 24h and 24i, and the support rollers 18 and 18a are rotatably provided. Thus, by providing the brackets 29 and 29a, it is possible to cope with the drum cans 50 having various diameters, and the support rollers 18 and 18a freely rotate. Therefore, the friction with the outer peripheral surface of the drum can 50 is small, and the drum can 50 can be smooth. Can be transported.
The other ends of the brackets 59 and 59a are connected to the hinge lots 23 and 23a via the pins 24 and 24a, and the hinge lots 23 and 23a are rotatably provided to the brackets 59 and 59a. . Further, the other ends of the hinge lots 23 and 23 a are connected to the bracket 32 via pins 24 b and 24 c, and the hinge lots 23 and 23 a are provided so as to be rotatable with respect to the bracket 32.
The material of the support rollers 18 and 18a is preferably a softer material than the drum can 50 such as resin or rubber in order to contact the chime portion of the drum can 50.

For this reason, the brackets 29 and 29a of the centering unit 20 move symmetrically with respect to the conveyance direction of the drum can 50.
The brackets 29 and 29a are restricted by a stopper (not shown) so that the intersection angle θ3 is an opening of about 0 to 50 degrees. By doing so, the force is also urged in the direction opposite to the conveying direction of the drum can 50, so that the conveying speed of the drum can 50 is suppressed. Furthermore, the diameter of the chime portion of the drum can 50 varies somewhat depending on the plate thickness and the number of chime turns, but it is possible to cope with these differences by providing a margin for the crossing angle.

The end of the bracket 59a is connected to the end of the cylinder 43 via a pin 24d, and the cylinder 43 is provided to be rotatable with respect to the bracket 59a. Further, the other end portion of the cylinder 43 is connected to the mounting plate 58 via a pin 24 e, and the cylinder 43 is provided to be rotatable with respect to the mounting plate 58. The attachment plate 58 is fixed to the beam member 42. Moreover, the cylinder 43 uses the type which always urges | biases to a contraction direction.
As a result, the support rollers 18 and 18a are urged toward the center in the radial direction of the drum can 50. Therefore, by providing a grip force that elastically supports the drum can 50, the conveyance speed of the drum can 50 is reduced. Furthermore, the drum can 50 can be slowly conveyed downstream thereafter by applying a larger conveying force to the grip force. In addition, since the brackets 29 and 29a are rotatably provided in a direction in which the drum can 50 is pushed wider than the diameter of the drum can 50, the drum can 50 can be smoothly conveyed simply by releasing the stoppers 14a and 14b.

In addition, a bearing 48 is provided at the center of the bracket 32 to reduce friction, and is connected to the beam member 42 via the rotating shaft 30.
This is because the bracket 32 repeats the rotation operation at intervals of several seconds, and therefore a bearing 48 is provided to smoothly perform the rotation operation.
The beam member 42 and the base member 41 are preferably made of lightweight and strong aluminum. This is to reduce the center of gravity of the drum can printing / drying device main body 17 and to improve stability by reducing the weight of the mounting tool 54 at the upper part. However, the support of the mounting tool 54 is separated from the drum can printing / drying device main body 17. But it ’s okay.

As shown in FIG. 3, hinge rods 23 and 23 a, brackets 32, 59 and 59 a, a cylinder 43, and a mounting plate 58 are provided on the upper surface side of the beam member 42 of the centering unit 20. By doing so, the hinge function can be configured by the hinge rods 23 and 23a and the bracket 32 at a position where there is no hindrance to the conveyance of the drum can 50.
Further, the lower surfaces of the base member 41 and the beam member 42 are provided with support rollers 18 and 18a and brackets 29 and 29a necessary for contacting the drum can 50. By doing so, the length of the pins 24h and 24i of the support rollers 18 and 18a can be shortened, and the urging force of the cylinder 43 can be reliably transmitted to the drum 50.

The movement of the centering unit 20 will be described with reference to FIGS. The drum can 50 is carried by the roller conveyor 12 from the upstream in the transport direction. Then, the upper outer peripheral surface 56 of the drum can 50 is sandwiched between the support rollers 18 and 18a, and the conveyance speed of the drum can 50 is reduced. Thereafter, since the downstream conveying force due to the rotation of the roller 15 is larger than the force sandwiched between the support rollers 18 and 18a, the ends of the brackets 29 and 29a are gradually pushed outward in the radial direction of the drum 50. Thus, the drum 50 is conveyed downstream while decelerating. Immediately thereafter, the support rollers 18 and 18a remain in contact with the drum can 50, and the drum can 50 hits the stoppers 14a and 14b and stops. Then, at the position where the drum can 50 is stopped, the induction heating unit 33 attached to the arm 35 whose axis is outside the roller conveyor 12 rotates in the horizontal direction, whereby the printing on the printing surface 51 of the drum can 50 is dried. The

Next, the configuration of the drying unit 27 will be described with reference to FIGS. 6, 7, and 8.
One end of an arm 35 is connected to the fixed frame 28 of the drying unit 27 via a bearing 36 and a rotary shaft 31, and the arm 35 is attached to the fixed frame 28 so as to be rotatable. An induction heating unit 33 having a concave coil support portion 34 is attached to the arm 35 along the drum can 50. When the printing surface 51 is heated close to the drum can 50 by forming a concave surface along the drum can 50, the coil support portion 34 has a substantially equal interval (here, copper or aluminum) with respect to the printing surface 51 of the drum can 50. This is because the gap from the surface of the manufactured high-frequency cable to the drum peripheral surface can be kept at about 4 to 30 mm), and the printing surface 51 can be heated uniformly. In addition, the coil support portion 34 is made of a structure in which a flexible non-metallic heat insulating insulating material and / or a resin insulating material are laminated to prevent generation of eddy current and prevent heating. And a concave surface can be formed.

Further, the arm 35 whose base that is the center of rotation (rotation) in the horizontal direction is outside the roller conveyor 12 is connected to an intermediate portion via one end of the coil front / rear cylinder 49 and a pin 37, and the coil front / rear cylinder 49. Is connected to the fixed frame 28 via a pin 37a. Then, the coil front and rear cylinders 49 are extended and retracted to rotate in the horizontal direction about the rotation shaft 31. Moreover, in another system, you may move back and forth in the width direction at right angles to the roller conveyor 12 by a slide system or the like.
Further, the arm 35 is provided with roller guides 38 and 38a (cam followers) for preventing interference to maintain an appropriate distance from the printing surface 51 of the drum 50 through the roller arms 64 and 64a. Yes. Thereby, since the coil support part 34 does not approach the drum can 50 more than necessary, excessive heating can be prevented and interference with the drum can 50 can be prevented. The roller guides 38 and 38a may be made of non-magnetic metal or resin that is not induction-heated. However, in the case of incorporating a magnetic part, it is desirable to reduce the influence of the induction electric field at a distance of 40 mm or more from the heating coil 39. .

On the back surface side of the concave coil support portion 34 along the drum can 50, a litz wire 55 that is wound in an elliptical shape or a quadrangular shape including the range of the print surface 51 and wound in a spiral shape, A heating coil 39 is formed, and the heating coil 39 is disposed substantially parallel to the concave coil support portion 34. The heating coil 39 is supplied with high frequency power of 5 to 40 kHz (preferably around 20 kHz) from the high frequency power supply 44. Therefore, the printing surface 51 facing the coil support portion 34 can be heated evenly. After the metal plate of the drum can 50 in the vicinity of the spiral heating coil 39 is heated by high-frequency heating for several seconds, the high-temperature heat is lowered while spreading in the metal plate of the drum can 50 by heat conduction. Therefore, even if the range of the printing surface 51 deviates from the heating range of the metal plate of the drum can 50 in the vicinity of the heating coil 39 (for example, about 30 mm), it can be dried with residual heat.

And as for the electrical performance, the high frequency power supply 44 has a power capacity ((metal plate heating range weight × specific heat × temperature rise temperature) that can raise the heating range of the metal plate of the drum can 50 near the heating coil 39 to the target temperature. + Heat radiation amount) / heating time), the temperature of the printing portion of the drum can 50 can be increased in about 1.5 to 3 seconds. The highest temperature achieved by high-frequency heating is preferably a temperature at which the coating surface 51 and the printing ink before heating the printing surface 51 are not deteriorated, and the temperature at which the ink dries within a predetermined time in the subsequent process according to the ambient temperature and humidity. The induction heating unit 33 may be provided with a cooling fan 63 on a surface other than the concave coil support portion 34. The cooling fan 63 cools the heating coil 39 by sending air toward the inside of the induction heating unit 33. FIG. 6 shows an example in which the cooling fan 63 is provided on the rear surface of the induction heating unit 33, and a plurality of air holes 62 are provided on the rear side of the coil support portion 34 and on the upper, lower, left, right, upper, lower, left, or right side surfaces. Therefore, the heated air in the vicinity of the heating coil 39 is exhausted and cooled from the vent hole 62 due to the chimney effect, so that the temperature rise of the heating coil 39 is suppressed.

Next, the drying operation of the drying unit 27 will be described with reference to FIGS.
As shown in FIG. 9, a case where the drum can 50 is not in a position to be heated on the roller conveyor 12, that is, a case where the induction heating unit 33 is in a standby state will be described.
In this case, the induction heating unit 33 is in a standby position stored in the fixed frame 28. In this standby state, the coil front and rear cylinders 49 are in a contracted state. In this state, the heating unit is not energized and is housed in the fixed frame 28, so that the induction heating unit 33 can be kept at a position that does not interfere with the conveyance of the drum can 50.

Next, as shown in FIG. 10, the rotation operation of the induction heating unit 33 will be described in the case where the drum can 50 is stopped by the stoppers 14a and 14b and the drum can 50 is heated.
In this state, the induction heating unit 33 has moved to a position close to the printing surface 51 of the drum can 50. In this state, the coil front / rear cylinder 49 is in an extended state.

In this state, the coil support part 34 of the induction heating unit 33 is close to the drum can 50 at an interval of 3 to 25 mm. And in the position which dries the drum 50, the high frequency current is supplied with the heating coil 39 of the back surface side of the coil support part 34 for the time within 1.5 to 3 second. Then, since the drum can 50 is made of a magnetic metal (for example, a steel plate, a stainless steel plate, a hot dip galvanized steel plate), an eddy current is induced in the metal plate of the drum can 50 facing the coil support portion 34, and this eddy current is generated. As a result, the printing surface 51 is heated. Then, when the printing surface 51 rises in temperature (for example, around 140 ° C.), the water-based ink on the printing surface 51 is dried. After that, after the energization time is finished, the induction heating unit 33 is retracted. Then, the stoppers 14a and 14b are released, the drum can 50 is transported downstream in the transport direction, and the printing surface 51 is dried by residual heat in a subsequent process (for example, before entering the warehouse).

A cable 45 for supplying high-frequency power is wired from the side surface of the induction heating unit 33, and a cable support member 46 extending upward from the upper surface side portion of the induction heating unit 33 is provided. As described above, the cable 45 includes the fixed wiring portion 60 and the free wiring portion 61. The fixed wiring portion 60 is fixed by a cable fixing member 52 along the cable support member 46. The free wiring portion 61 is located above the cable fixture 52 and is freely wired without being fixed. Further, the induction heating unit 33 performs an operation of approaching and retracting the drum can 50 at a predetermined angle of 90 degrees or less about the rotation shaft 31 at intervals of several seconds, so that the cable 45 connected to the induction heating unit 33 is also twisted. . However, since the free wiring portion 61 is wired with a vertical or nearly vertical inclination along the rotation axis 53, the twisting force and deformation amount applied to the cable 45 are reduced.

Next, a drum can print drying method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5, 9, and 10.
In the drum can print drying method according to the embodiment of the present invention, the drum can 50 printed on the printing surface 51 at a predetermined angular position on the outer periphery is conveyed from the upstream to the downstream via the roller conveyor 12, and the roller conveyor 12 is specified. A drum can printing drying method that stops at a position and dries the printing surface 51, wherein the drum can 50 conveyed by the roller conveyor 12 is paired from both sides in the width direction of the roller conveyor 12 at a position before a specific position of the roller conveyor 12. The first step of adjusting the width direction position of the drum can 50 with respect to the roller conveyor 12 by elastically sandwiching the support rollers 18 and 18a, and supporting the upper portion of the drum can 50 immediately before the stop position of the drum can 50, and the roller conveyor 12 The stoppers 14a and 14b are protruded from the gap between the rollers 15 in the roller 15 and are transported by the roller conveyor 12. A second step in which the can 50 is stopped at a specific position; a third step in which an induction heating unit 33 having a concave surface having a gap of a certain distance from the drum can 50 on the printing surface 51 of the drum can 50; A fourth step of supplying high frequency power to the unit 33 from the high frequency power supply 44 for a predetermined time, and a fifth step of retracting the induction heating unit 33 and releasing the stoppers 14a and 14b and transporting the drum can 50 by the roller conveyor 12 Have. Details will be described below.

In the production line of the drum can 50, the product number and the like are printed with water-based ink on the printing surface 51 on the lower outer peripheral surface of the drum can 50 by a printing unit (PC coder) 16 provided on the side of the belt conveyor 11. Will be sent to.
In the first step, the fed drum can 50 is provided in the centering unit 20 from both sides in the width direction of the roller conveyor 12 at a position before the specific position of the roller conveyor 12 (position where the drum can 50 is stopped by the stoppers 14a and 14b). The upper portion of the drum 50 can is elastically sandwiched between the paired support rollers 18 and 18a. As a result, the position in the width direction of the drum can 50 with respect to the roller conveyor 12 is adjusted, the conveyance speed of the drum can 50 is reduced, and the upper portion of the drum can 50 is stably supported.

Next, in a 2nd process, the stoppers 14a and 14b are protruded from the clearance gap between the rollers 15 in the roller conveyor 12, and the drum can 50 conveyed by the roller conveyor 12 is stopped at a specific position. At this time, since the upper portion of the drum 50 is elastically sandwiched between the support rollers 18 and 18a, the upper portion of the drum 50 can be prevented from falling even if the conveying speed is high. As long as there is no interference with the drum can after drying, the timing of projecting the stoppers 14a and 14b can be made to project before the first step and stand by.

Further, in the third step, the induction heating unit 33 is brought closer to the printing surface 51 of the drum can 50 stopped at a specific position by extending the coil front and rear cylinders 49. The induction heating unit 33 has a concave surface having a gap of a certain distance from the drum can 50. The gap of the certain distance is a forward end or a forward end stopper (not shown) of the coil front and rear cylinder 49. , And is determined so as to maintain a distance of 3 to 25 mm. This is to keep the temperature rise of the heated portion of the drum can 50 constant. As a result, the variation in drying of the water-based ink can be made constant. Further, when the gap of this constant distance is small, the outer diameter of each part of the drum can 50 varies depending on the plate thickness, the number of times of winding with the chime, etc., and the concave coil support 34 and the drum can 50 directly interfere with each other. In order to prevent this, the roller guides 38 and 38a provided on the concave surface are attached to positions closer to the drum can 50 than the coil support portion 34, and the roller guides 38 and 38a and the drum can 50 are brought into contact with each other. Position with a minimum clearance.

In the fourth step, high frequency power is supplied from the high frequency power supply 44 to the induction heating unit 33 adjacent to the drum can 50 for a predetermined time. The energization time is a time within 1.5 to 3 seconds, but the temperature of the printing surface 51 can be increased by the eddy current generated on the printing surface 51. This control of the temperature rise can be arbitrarily adjusted in the range of 90 to 220 ° C. by setting the energization time and the output of the induction heating unit 33. As a result, the printing can be dried using the induction heating unit 33 corresponding to the production line of drums having a high conveyance speed.

In the fifth step, the energization to the induction heating unit 33 is stopped, and the coil front and rear cylinders 49 are contracted and retracted. Then, the stoppers 14 a and 14 b are released and the drum can 50 is conveyed by the roller conveyor 12. Thereafter, the heated water-based ink on the printing surface 51 is completely dried by remaining heat.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
For example, although the drum can has been described as a normal type 200L can, the present invention can be applied to a small and medium can (18L or more and less than 200L) and a pail can (18L or 20L can with a vine or a hand ring).
In addition, if the concave shape of the induction heating unit is a concave shape at the center, even if the inner peripheral surface side is not a curved surface (for example, R surface), the plane and the plane intersect at an angle of 120 degrees, for example. It may be formed.
Further, the drum can be a high frequency power source having a frequency in the range of 1 to 100 kHz so that a material such as non-magnetic SUS can be used without being a magnetic material. The ink is not limited to water-based ink, but can be applied to oil-based ink, magnetic ink, and the like. The product number includes the product specification.

DESCRIPTION OF SYMBOLS 10: Drum can printing drying apparatus, 11: Belt conveyor, 11a: Drive unit, 12: Roller conveyor, 12a: Drive unit, 13: Stopper unit, 13a: Stopper, 13b: Stopper, 14: Stopper unit, 14a: Stopper, 14b : Stopper, 15: Roller, 16: Printing unit, 16a: Printing unit, 17: Drum can printing and drying apparatus main body, 18: Support roller, 18a: Support roller, 19: Belt, 20: Centering unit, 22: Stopper cylinder, 23 : Hinge rod, 23a: Hinge rod, 24: Pin, 24a-24i: Pin, 25: Control unit, 26: Printing roll, 27: Drying unit, 28: Fixed frame, 29: Bracket, 29a: Bracket, 30: Rotation Shaft, 31: rotating shaft, 32: bracket, 33: Conductive heating unit, 34: coil support, 35: arm, 36: bearing, 37: pin, 37a: pin, 38: roller guide, 38a: roller guide, 39: heating coil, 40: mount, 41: base material, 42: beam material, 43: cylinder, 44: high frequency power supply, 45: cable, 46: cable support material, 47: case, 48: bearing, 49: cylinder before and after coil, 50: drum can, 51: printing surface, 52: cable Fixing tool, 53: rotation axis, 54: mounting tool, 55: litz wire, 56: upper outer peripheral surface, 57: lower outer peripheral surface, 58: mounting plate, 59: bracket, 59a: bracket, 60: fixed wiring section, 61 : Free wiring section, 62: Air vent, 63: Cooling fan, 64: Roller arm, 64a: Roller arm

Claims (6)

A roller conveyor that conveys drums printed on the printing surface from upstream to downstream;
A centering unit that is in the middle of the roller conveyor, adjusts the position in the width direction of the drum can relative to the roller conveyor, and elastically supports the upper portion of the drum can immediately before the stop position of the drum can;
A stopper for stopping the drum can by protruding from a gap between the rollers at a predetermined position of the roller conveyor, contacting the lower portion of the drum can conveyed by the roller conveyor,
An induction heating unit that dries the printing surface at a predetermined angular position with respect to the conveying direction of the roller conveyor of the drum can stopped by the stopper, which advances and retreats in the width direction with respect to the roller conveyor. Drum can printing drying device. 2. The drum print drying apparatus according to claim 1, wherein the induction heating unit has a base portion that is a center of horizontal rotation attached to one side of an arm outside the roller conveyor. 3. The drum can printing and drying apparatus according to claim 2, wherein the induction heating unit is connected to a high-frequency power source fixedly arranged via a cable, and the cable further includes a fixed wiring portion fixedly arranged on the arm, and the fixed wiring. And a free wiring portion that is wired at a vertical or near-perpendicular angle connecting the high-frequency power source and absorbs torsion of the cable by the rotation of the arm. Drying equipment. The drum can print drying apparatus according to any one of claims 1 to 3, wherein the induction heating unit has a concave surface along the drum can, and includes a roller guide for positioning the induction heating unit and the drum can. Drum can printing drying device. 5. The drum can printing and drying apparatus according to claim 4, wherein the induction heating unit includes a heating coil and a coil support portion made of a non-magnetic metal that supports the heating coil and has the concave surface, and is provided behind the coil support portion. Has a plurality of vent holes. A drum can printing drying method in which a drum printed on a printing surface at a predetermined angular position on the outer periphery is conveyed from upstream to downstream via a roller conveyor, stopped at a specific position on the roller conveyor, and dried on the printing surface. ,
The drum can transported by the roller conveyor at a position before the specific position of the roller conveyor is elastically sandwiched between pairs of support rollers from both sides in the width direction of the roller conveyor, and the width direction of the drum can with respect to the roller conveyor A first step of adjusting the position and supporting the upper portion of the drum just before the stop position of the drum,
A second step of causing a stopper to protrude from a gap between the rollers on the roller conveyor, and stopping the drum can conveyed at the roller conveyor at a specific position;
A third step of closely arranging an induction heating unit having a concave surface having a gap of a certain distance from the drum can on the printing surface of the drum;
A fourth step of supplying high-frequency power to the induction heating unit from a high-frequency power source for a predetermined time;
A drum can printing and drying method comprising: a fifth step of retracting the induction heating unit and releasing the stopper and transporting the drum can by the roller conveyor.

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