JPH07251931A - Can self rotating device, coating device and light illuminating device - Google Patents

Abstract

PURPOSE:To provide a can self rotating device capable of allowing self-rotation of an alluinum can, etc., at a high speed without giving external damages or peeling off prints on its side surface. CONSTITUTION:An alluminum can self rotating device 30 is structured by disposing, along a fan-shaped arc, a plurality of coils 3 for supplying magnetic fluxes changed in sine waveforms while keeping a specified phase difference between adjacent coils. An aluminum can 2 held in the holding part 10 of a star wheel 5 reaches the position of the aluminum can self rotating device 30 according to the rotation of the star wheel 5, and when magnetic fluxes are supplied from a coil 31 to the side thereof, this can is self rotated in an arrow direction being held in the holding part 10. Then, protection paints are uniformly sprayed from an injection nozzle 7 toward a bottom part positioned on the side opposite to the opening part 2a of an alluminum can 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can rotation device for performing some processing while rotating the can in a manufacturing process of a can having conductivity but weak magnetism or reverse magnetism such as an aluminum can. And a coating device and a light irradiation device using the can rotation device.

[0002]

2. Description of the Related Art For example, in the process of manufacturing an aluminum can containing fruit juice or salt as a content, a protective paint is sprayed on the inside of the aluminum can in order to protect the aluminum can from corrosion by the content. In addition, some aluminum cans are subjected to high temperature sterilization. When high temperature sterilization is performed using an ordinary aluminum can, the surface of the bottom of the aluminum can may become dark. Therefore, in the case of an aluminum can for such an application, heat-resistant paint is sprayed on the bottom of the aluminum can during the manufacturing process of the aluminum can so as not to spoil the appearance of the aluminum can. At this time, in order to apply the coating material evenly to the inside and bottom surfaces of the aluminum can, the coating material is sprayed onto the aluminum can while rotating the aluminum can using an aluminum can rotating device.

FIG. 6 is a view for explaining an example in which an aluminum can rotating device is used in a spraying process of spraying paint on the inside and bottom surfaces of an aluminum can. As shown in FIG. 6, in the spraying process, the aluminum can 2 is dropped toward the star wheel 4 from the carry-in passage 1 by using the in-feed can stopper 3 with proper timing. The aluminum cans 2 are held by concave holding portions 10 provided at equal intervals along the outer circumference of the star wheel 4 located below the carry-in path 1, and revolve according to the rotation of the star wheel 4. The aluminum can 2 is provided at the bottom of the star wheel 4 opposite to the opening 2a of the aluminum can 2 as shown in FIG.
The pad 8 as shown in (B) is attracted and fixed by the suction force from the suction port 8a. When the aluminum can 2 reaches the position of the spray nozzle 14, the spraying nozzle 14 positioned on the side of the opening 2a of the aluminum can 2 sprays the protective paint inside the aluminum can 2 through the opening 2a. At this time,
As shown in FIG. 7 (B), the pad 8 rotates in a predetermined direction according to the power from the belt 9, and the aluminum can 2 also rotates accordingly, so that the paint from the injection nozzle 14 opens in the opening 2a. Is sprayed uniformly on the inside of the aluminum can 2 via.

Aluminum can 2 held by a star wheel 4
Stops the supply of suction force from the suction port 8a at a position where the star wheel 4 and the star wheel 5 located below the star wheel 4 are closest to each other.
It is supplied and held to the holding portion 10 of the star wheel 5 which is already in the suction state. The aluminum can 2 held by the holding portion 10 of the star wheel 5 revolves in accordance with the rotation of the star wheel 5, and at the position of the injection nozzle 7, as shown in FIGS. 6 and 7 (A), the aluminum can 2 rotates. Belt 6 of device 6
While contacting e, the belt 6e rotates in a predetermined direction according to the movement of the belt 6e, and the paint for protection from the spray nozzle 7 is evenly sprayed on the surface of the bottom of the aluminum can 2. The injection nozzle 7 applies the protective paint to the aluminum can 2 held by the star wheel 5 from the bottom opposite to the opening 2a at the position where the aluminum can 2 contacts the belt 6e of the aluminum can rotating device 6. It is arranged to spray on.

The holding portion 10 of the star wheel 5 is provided with, for example, three rollers 11 for smoothing the rotation of the aluminum can 2 by the aluminum can rotating device 6, and the aluminum can 2 is in contact with the roller 11. It is held by the holding unit 10.
On the other hand, the aluminum can rotating device 6 has a driving roller 6a and rollers 6c and 6d. The driving roller 6a and the roller 6c have a belt 6b and the rollers 6c and 6d have a belt 6d.
Is attached, and the belt 6e moves according to the rotational force from the drive roller 6a. In addition, guide portions 12 and 13 for guiding the aluminum can 2 held by the holding portions 10 of the star wheels 4 and 5 so as not to move to the outside of the star wheels 4 and 5 are provided near the outer circumferences of the star wheels 4 and 5. It is provided.

In addition, when printing is performed on the side surface of an aluminum can or the like with an ultraviolet curable resin ink, an ink drying step of drying the ink is performed. FIG. 8A is a plan view of the UV oven that performs the ink drying step, and FIG. 8B is a side view of the UV oven taken along the section line AA shown in FIG. 8A. In the conventional UV oven, as shown in FIG.
As shown in (B), a pin chain 2 having a plurality of pins 21 for hooking the aluminum can 2 at predetermined intervals.
A total of twelve UV lamps 22 are arranged along the 0, six on one side of the pin chain 20 and six on the other side. In the pin chain 20, the aluminum can 2 is hooked on each pin 21, and the aluminum can 2 is carried out from the carry-in port 23 to the carry-out port 2.
It conveys to 4. In the carrying process, the aluminum can 2 is irradiated with ultraviolet rays from the UV lamps 22 provided on both sides of the carrying route, and the ink printed on the aluminum can 2 is cured.

[0007]

However, FIG. 6 described above is used.
In the aluminum can rotation device 6 shown in FIG. 7 (A), if the rotation speed of the drive roller 6a is increased according to the rotation speed of the star wheel 5 in order to increase the processing speed, the belt 6
b and 6e are disengaged from the drive roller 6a and the rollers 6c and 6d, so-called derailment occurs, the movement of the belt 6e becomes poor, and the side surface of the aluminum can 2 is dented. As a result, there is a problem in that the rotation speed of the drive roller 6a cannot be increased and the processing speed in the spray process cannot be increased. Further, since the roller 6e contacts the side surface of the aluminum can 2, there is a problem that the printing on the side surface of the aluminum can 2 is dropped.

Further, in the UV oven shown in FIGS. 8A and 8B described above, as many as 12 UV lamps 22 are required to cure the ink printed on the aluminum can 2, and the apparatus becomes large in scale. And there is a problem of high price. At this time, if the aluminum can 2 is transported by the pin chain 20 while rotating, the area of the aluminum can 2 where one UV lamp 22 can irradiate ultraviolet rays can be increased, and the number of UV lamps can be reduced. However, since the uncured ink is printed on the side surface of the aluminum can 2 in the UV oven, the contact type aluminum can rotating device 6 as shown in FIG. 6 cannot be used.

The present invention has been made in view of the above-mentioned problems of the prior art, and an aluminum can rotating device and an aluminum can rotating device capable of rotating an aluminum can at high speed without damaging the aluminum can or losing printing on the side surface thereof. An object is to provide a coating device using the device. Another object of the present invention is to provide a light irradiation device capable of reducing the size and cost of a UV oven.

[0010]

In order to solve the above-mentioned problems of the prior art and to achieve the above-mentioned object, the can rotation device of the present invention has a can which has conductivity but weak magnetism or reverse magnetism. A magnetic flux generating means for supplying a magnetic flux that changes in a sine wave shape to the side surface position of the can sent to the transport path along the transport path and rotating the can in a non-contact manner.

Further, in the coating apparatus of the present invention, a sinusoidal change is formed on the side surface position of the can sent to the transport path along the transport path of the can having conductivity but weak magnetism or reverse magnetism. And a spraying means for spraying the treatment liquid toward the bottom of the can that rotates in response to the magnetic flux.

Further, according to the light irradiation device of the present invention, the side surface of the can which is sent to the transfer path is provided by the transfer path of the can having the conductivity but the weak magnetism or the reverse magnetism.
A can rotating means is provided on the outer circumference of the can, which supplies a magnetic flux that changes in a sinusoidal shape and has a magnetic flux generating part that rotates the can in a non-contact manner and a can that rotates according to the magnetic flux of the can rotating means. And a light emitting means for irradiating light for curing the printed surface with the photocurable ink.

[0013]

In the can rotating device of the present invention, the magnetic flux from the magnetic flux generating means is supplied to the side surface of the can sent to the predetermined conveying path. When the magnetic flux is supplied, an eddy current corresponding to the magnetic flux is generated at the side surface of the can. A force indicated by Fleming's left-hand rule acts on the side surface of the can according to the eddy current and the supplied magnetic flux, and the can causes the can to rotate in a predetermined direction.

Further, in the coating apparatus of the present invention, the can rotates on the basis of the magnetic flux from the magnetic flux generating section on the same principle as the can rotating device. At the same time, the treatment liquid is jetted toward the bottom of the rotating can.

Further, in the light irradiation device of the present invention, the can rotates on the basis of the magnetic flux from the magnetic flux generating section on the same principle as the can rotating device. At the same time, the printing surface of the photo-curable ink applied to the outer circumference of the rotating can is irradiated with light from the light emitting means, and the ink is cured.

[0016]

EXAMPLE An aluminum can rotating device and a coating device using the aluminum can rotating device according to embodiments of the present invention will be described below. FIG. 1 is a diagram for explaining an example in which the aluminum can rotating device according to the present embodiment is used in a spraying process of spraying a protective paint on the inner and bottom surfaces of an aluminum can. In the spray process shown in FIG. 1, the aluminum can rotating device 6 used in the spray process shown in FIG. 6 is replaced with an aluminum can rotating device 30. That is, the spray nozzle 14 sprays the protective paint on the inside of the aluminum can 2 held by the star wheel 4, and the spray nozzle 7 sprays the protective paint on the bottom of the aluminum can 2 held by the star wheel 5. To be done. At this time, the coating device is, for example, a star wheel 5,
It is composed of an injection nozzle 7 and an aluminum can rotating device 30. Among the constituent elements shown in FIG. 1, constituent elements given the same reference numerals as those in FIG. 6 are the same as the constituent elements described in the above-mentioned prior art.

The aluminum can rotation device 30 will be described in detail. 2 is an enlarged view of the aluminum can rotation device 30 shown in FIG. 1, and FIG. 3 is a side view of the vicinity of the injection nozzle 7 as seen from the direction of arrow A shown in FIG. As shown in FIG. 2, the aluminum can rotation device 30 includes 16 coils 31 and a star wheel 5.
Is arranged in a fan-shaped arc shape having a central angle of 120 ° along the star wheel 5 at a predetermined interval. 1
To the six coils 31, three-phase AC currents of R, S, and T are adjacent to the six coils 31 in order from the coil 31 located at the end on the carry-in side of the aluminum can 2 in the rotation direction of the star wheel 5.
It is repeatedly flowed for each one coil 31. For example, the coil 31 located at the end on the carry-in side of the aluminum can 2 has an R phase,
The coil 31 adjacent to the coil 31 has an S phase, and the next adjacent coil 31 has a T phase. At this time, for example, in the R phase, the current i expressed by the equation (1) is
The current i2 represented by the equation (2) is applied to the 1st and S-phases, and the current i3 represented by the equation (3) is applied to the T-phase.

I1 = Im × sin ω0t (1) i2 = Im × sin (2πt / T-2π / 3) (2) i3 = Im × sin (2πt / T-4π / 3) (3)

In equations (1) to (3), Im represents an amplitude current, T represents a cycle, and t represents time. In this way, the current has a phase difference of 2π / 3 between the adjacent coils 31. As shown in FIG. 2, the injection nozzle 7 for spraying the protective paint toward the bottom portion 2b of the aluminum can 2 held by the star wheel 5 has a center of the arc of the coil 31 arranged in an arc shape. Located in the vicinity. In addition, as shown in FIG.
The aluminum can 2 held by is arranged so that its center is located near the center of the side surface.

In the aluminum can rotating device 30, as described above, the R, S, and T phase alternating currents are passed through the 16 coils 31, so that the aluminum can 2 conveyed while being held by the star wheel 5 is conveyed. An eddy current is generated on the side surface in accordance with the magnetic flux from the coil 31, and the magnetic force generated according to Fleming's left-hand rule in accordance with the eddy current and the magnetic flux from the coil 31 is used as a rotational force to rotate the aluminum can 2 in FIG. Arrow B
Rotate in the direction of. At this time, the aluminum can rotation device 30
Then, spray time of one aluminum can 2 is about 30 mse
c to about 80 msec, and it is necessary to rotate the aluminum can 2 once or more within the spray time. Therefore, the aluminum can 2 is about 750 (= 1 revolution × 6000 msec / about 80).
msec) rpm to about 2000 (= 1 rotation x 6000 m
(sec / about 30 msec) rpm is rotated.

Hereinafter, the principle of causing the aluminum can 2 to generate a rotational force by the coil 31 will be described with reference to FIGS. 4 (A) and 4 (B). FIG. 4 (A) is a diagram for explaining the relationship between the magnetic flux from the coil 3 and the eddy current generated on the surface of the aluminum can 2, and FIG. 4 (B) is the eddy current generated on the surface of the aluminum can 2 and the coil 3. FIG. 6 is a diagram for explaining the relationship between the magnetic flux from the and the magnetic force generated on the surface of the aluminum can 2. As shown in FIG. 4A, a current I1 of R phase flows in the coil 31 (R) clockwise, for example, and a magnetic flux φ1 is generated toward the surface of the aluminum can 2 according to the current I1. This magnetic flux φ1 causes an eddy current that flows counterclockwise on the surface of the aluminum can 2. This eddy current is, for example, as shown in FIG.
Point A1, point B1, point C1, and point D1 shown in (B) have current vectors i11, i12, i13, and i14 directed to the left, downward, right, and upward, respectively. At this time, due to the eddy current and the magnetic flux φ1, downward magnetic forces F11 and B are applied to the point A1 according to Fleming's left-hand rule.
A rightward magnetic force F12 is generated at one point, an upward magnetic force F13 is generated at the point C1, and a leftward magnetic force F14 is generated at the point D1.

From the same principle, as shown in FIG. 4B, a downward magnetic force F is applied to the point A2 in accordance with the eddy current i2 generated on the surface of the aluminum can 2 by the coil 31 (S).
21 and B2, rightward magnetic force F22, point C2 upward magnetic force F23, point D2 leftward magnetic force F24.
Occurs. In addition, the coil 31 (T) allows the aluminum can 2
In accordance with the eddy current i3 generated on the surface of, the downward magnetic force F31 is applied to the A3 point, the rightward magnetic force F32 is applied to the B3 point,
An upward magnetic force F33 is generated at the point C3, and a leftward magnetic force F34 is generated at the point D3.

On the surface of the aluminum can 2, point B1 and point D
1, the point B2, the point D2, the point B3 and the point D3 are located along the arc direction formed by arranging the 16 coils 31, and the electromagnetic forces F12, F14, F22 generated at these points,
F24, F32, and F34 affect the rotation (rotation) of the aluminum can 2 rotatably held by the star wheel 5 about the central axis via the roller 10. At this time, due to the phase difference between the R-phase, S-phase, and T-phase currents, the aluminum can 2 shown in FIG.
The electromagnetic forces F12, F22 and F32 acting rightward with respect to the surface of the aluminum can 2 effectively act, and the aluminum can 2 rotates rightward, that is, in the direction of arrow B in FIG.

A series of operations in the spraying process will be described below. As shown in FIG. 1, the aluminum can 2 carried in through the carry-in path 1 is dropped toward the star wheel 4 while being properly timed by the infeed can stopper 3. The aluminum can 2 dropped toward the star wheel 4 is adsorbed and held by the concave holding portion 10 and revolves in accordance with the rotation of the star wheel 4. Then, the aluminum can 2 revolves in accordance with the rotation of the star wheel 4, and when it reaches the position of the injection nozzle 14,
As shown in FIG. 7 (B), the injection nozzle 1 rotates while rotating in synchronization with the rotation of the pad 8 by the belt 9.
The paint from 4 is evenly sprayed into the can. And
When the aluminum can 2 reaches the position closest to the star wheel 5 according to the rotation of the star wheel 4, the holding portion 10
The adsorbed state is released and is transferred to the holding portion 10 of the star wheel 5 that is already in the adsorbed state.

The aluminum can 2 has a star wheel 5
When reaching the position of the aluminum can rotation device 30 in response to the rotation of the above, the aluminum can rotation device 30 rotates in the direction of arrow B shown in FIG. 2 in a non-contact state based on the principle described above. Then, when the aluminum can 2 reaches the position of the spray nozzle 7 in accordance with the rotation of the star wheel 5 while rotating in the direction of arrow B shown in FIG. 2, the paint from the spray nozzle 7 is evenly sprayed on the bottom of the can. It Then, when the aluminum can 2 reaches the position of the carry-out path 15 according to the rotation of the star wheel 5, the suction state of the holding portion 10 is released, and the aluminum can 2 is carried out via the carry-out path 15.

As described above, the aluminum can rotating device 30 is used to rotate the aluminum can 2 held by the star wheel 5 in a non-contact manner so that the paint from the injection nozzle 7 is applied to the bottom of the aluminum can 2. It can be applied uniformly.
Therefore, according to the aluminum can rotation device 30, the aluminum can 2
Conventional aluminum can rotation device 6 when rotating at high speed
There is no problem such as the removal of the drive belt that occurs in the above. Further, according to the aluminum can rotating device 30, since the aluminum can 2 is rotated in a non-contact manner, the printing on the side surface of the aluminum can 2 is not dropped or the side surface is not dented.

Further, when printing is performed on the side surface of an aluminum can using the ultraviolet curable resin ink, the aluminum can rotating device 40 can be used in a UV oven as a light irradiation device for drying the ink. FIG. 5 (A) is a plan view of the UV oven of the present embodiment in which the ink drying process is performed, and FIG. 5 (B) is a side view of the UV oven of the present embodiment taken along the line AA shown in FIG. 5 (A). is there. FIG. 5 (A),
As shown in (B), in the UV oven of the present embodiment, six UV lamps are provided on one side along a pin chain 20 having a plurality of pins 21 for hooking the aluminum can 2 at predetermined intervals. 22 and nine aluminum can rotation devices 40 are arranged on the other side. At this time, the inside of the UV oven is a dark room that shields light from the outside. The aluminum can 40 includes, for example, a plurality of coils connected to the pin chain 20.
It is arranged linearly along the line. Pin chain 2
0 indicates that the aluminum can 2 is hooked on each pin 21 and the aluminum can 2 is carried in from the carry-in port 23. The loaded aluminum cans 2 are rotationally driven in a non-contact manner in the direction of arrow A in accordance with the magnetic flux from the coil at the position of each aluminum can rotating device 40, and rotate toward the direction of arrow A toward the carry-out port 24. Be transported.

In the carrying process, the aluminum can 2 is irradiated with ultraviolet rays from the UV lamps 22 provided on both sides of the carrying route, and the ink printed on the aluminum can 2 is cured. As described above, in the UV oven of this embodiment, the aluminum can 2 is conveyed while rotating in the direction of arrow A, so that the aluminum can 2 is irradiated with ultraviolet rays from one UV lamp 22 as compared with the case where the aluminum can 2 is not rotated. The side surface area of the can 2 can be increased,
The number of UV lamps can be reduced from 12 in the conventional UV oven shown in FIG. 8 to 6. In addition, the UV of this embodiment
In the oven, since the aluminum can 2 is rotationally driven in a non-contact manner, the printing on the side surface of the aluminum can 2 is not adversely affected.

In the above-mentioned embodiment, an aluminum can is exemplified as a can having conductivity but weak magnetism or reverse magnetism. However, the can used in the can rotation device, coating device and light irradiation device of the present invention is electrically conductive. The can is not limited to the aluminum can as long as the can is made of a material having a weak magnetic property or a reverse magnetic property. The can rotation device of the present invention can also be used in devices other than the coating device and the light irradiation device that require the can to rotate. In particular, when it is necessary to install the device in a place where there is only a small space, it is effective to use the can rotation device of the present invention.

[0030]

As described above, according to the can rotation device of the present invention, the conveyed can can rotate in a non-contact manner. Further, according to the can rotation device of the present invention, the can can rotate at high speed in a stable state. Further, according to the coating apparatus of the present invention, since the transported can can rotate on a non-contact basis, the coating material can be uniformly applied to the bottom of the can and, for example, the printing on the side surface of the can is adversely affected. Can be effectively suppressed. Further, according to the coating apparatus of the present invention, since the can can rotate at high speed in a stable state, the processing in the apparatus can be performed at high speed.
Further, according to the light irradiation device of the present invention, it is possible to reduce the size and cost of the device.

[Brief description of drawings]

FIG. 1 is a view for explaining an example in which the aluminum can rotating device according to the present embodiment is used in a spray process of spraying a protective paint on the inner and bottom surfaces of an aluminum can.

FIG. 2 is an enlarged view of the aluminum can rotating device shown in FIG.

3 is a side view of the vicinity of an injection nozzle as seen from the direction of arrow A shown in FIG.

FIG. 4A is a diagram for explaining the relationship between the magnetic flux from the coil and the eddy current generated on the surface of the aluminum can, and FIG. 4B is a diagram for explaining the eddy current generated on the surface of the aluminum can and the magnetic flux from the coil. FIG. 6 is a diagram for explaining the relationship with the magnetic force generated on the surface of the aluminum can.

FIG. 5 (A) is a UV of this embodiment for performing an ink drying step.
The oven top view, (B) is the sectional line AA shown in (A).
2 is a side view of the UV oven of the present embodiment in FIG.

FIG. 6 is a diagram for explaining an example in which a conventional aluminum can rotating device is used in a spraying process of spraying paint on the inside and bottom surfaces of an aluminum can.

7A is a rotation mechanism used when spraying paint on the bottom of an aluminum can in the spraying process shown in FIG. 6, and FIG. 7B is a rotation mechanism used when spraying paint on the inside of an aluminum can. FIG.

8A is a plan view of a conventional UV oven in which an ink drying step is performed, and FIG. 8B is a side view of the conventional UV oven taken along the line AA in FIG. 8A.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Carrying-in path 2 ... Aluminum can 2a ... Opening part 3 ... Infeed can stopper 4, 5 ... Star wheel 6, 30, 40 ... Aluminum can rotation device 6a ... Drive roller 6e ... Belt 7, 14 ... Injection nozzle 10 ... Holding part 11 ... Roller 12, 13 ... Guide part 15 ... Carry-out path 20 ... Pin chain 22 ... UV lamp 31 ... Coil

Claims (8)

[Claims] 1. A sinusoidally changing magnetic flux is supplied to a side surface position of a can sent to the transport path along the transport path of the can having conductivity but weak magnetism or reverse magnetism, A can rotating device having magnetic flux generating means for rotating a can in a non-contact manner. 2. The magnetic flux generating means rotates the can about 7 times.
2. Rotating at 50 rpm to about 2000 rpm.
The described can rotation device. 3. The can rotation according to claim 1, further comprising a can revolving means for revolving the can while adsorbing a side surface of the can, wherein the magnetic flux generating means revolves the revolving can. apparatus. 4. A magnetic flux that changes in a sinusoidal shape is supplied to a side surface position of a can sent to the transport path along a transport path of the can having conductivity but weak magnetism or reverse magnetism, A coating apparatus comprising: a can rotating means having a magnetic flux generating section for rotating the can in a non-contact manner; and a spraying means for spraying a treatment liquid toward the bottom of the can rotating according to the magnetic flux. 5. The magnetic flux generating section rotates the can about 75 times.
The coating apparatus according to claim 4, which rotates at 0 rpm to about 2000 rpm. 6. The coating device according to claim 4, further comprising a can revolving means for revolving the can while adsorbing a side surface of the can, wherein the magnetic flux generating section causes the revolving can to rotate. . 7. A magnetic flux that changes in a sinusoidal shape is supplied to a side surface position of the can sent to the transport path along the transport path of the can having conductivity but weak magnetism or reverse magnetism, A can rotating means having a magnetic flux generating section for rotating the can in a non-contact manner, and a can rotating on the basis of the magnetic flux of the can rotating means, to cure the printing surface of the photocurable ink applied to the outer periphery of the can. A light emitting device having a light emitting means for emitting light. 8. The light irradiation device according to claim 7, wherein the can rotating means and the light emitting means are provided in a dark room.