JP2001030462A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of printing a thick and long band-like material to be printed like a corrugated fiberboard or the like without difficulty. SOLUTION: The printer comprises conveying rollers 2 for conveying a material 1 to be printed along a conveying surface 3, a rotatable press roller 4 provided along the conveying surface adjacent to a conveying direction by the rollers 2 and brought into contact with a lower surface of the material, a printing drum 5 vertically movably disposed above the press roller, brought into contact with an upper surface of the material on the press roller and rotatably driven, and a drive means 21 for vertically moving the drum. A thickness sensor 30 senses a thickness of the material. The means 21 vertically moves a printing drum 8 based on the sensed thickness to decide an interval to the roller 4. Thus, no step is formed on the material during printing and conveying, and an excess load is not applied to the material. Since an interval between the drum and the press roller is regulated in response to the thickness of the material, the interval between the drum and the press roller is always stable, thereby stabilizing a finishing state of printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing on a printing medium, such as a cardboard box, which is thicker than ordinary printing paper and has a long strip shape when expanded.

[0002]

2. Description of the Related Art A cardboard box to be assembled into a box has a main body of the box and a lid portion which is connected to the main body by a fold. The main body portion is a portion of the peripheral wall of the box, and is developed in a band shape (or rectangular shape) having several folds before printing. A portion called a flap serving as a lid is integrally provided along a pair of opposing sides of the main body via a fold line. To assemble, the main body is connected in a ring shape, the main body is formed into a box shape along the crease, and the top and bottom surfaces of the main body are closed by combining flaps.

Generally, in the case of cardboard, some surface is printed on the surface of the main body portion, but in many cases, it is not printed on the flap. In the printing process, the main body and the flaps are unfolded and spread flat, and printed in a long strip shape. Conventionally, a screen printing device using a flat screen or a printing device in which a soft plate is wound around a cylindrical printing drum that is driven to rotate has been used.

FIG. 8 shows an example of a printing apparatus having a cylindrical printing drum. In this printing apparatus, a printing drum 100 is fixed at a predetermined position above a transport surface 102 of a cardboard 101 by a transport unit (not shown). An elevating unit 1 is provided below the printing drum 100.
There is 03. The lifting unit 103 includes the press roller 10
4 and a transport roller 105 disposed before and after the press roller 104, and can be moved up and down as a whole. The lifting unit 103 arranged on the transport surface 102 includes:
Receiving the cardboard 101 that has been transported, it rises,
Lift the cardboard 101. When the printing drum 100 rotates, the cardboard 101 is printed while being conveyed while being sandwiched between the printing drum 100 and the press roller 104. When the same printing is performed on a plurality of portions of the cardboard 101 having a long band shape, the lifting unit 103 descends when the printing drum 100 makes substantially one rotation and the first printing is completed. The cardboard 101 moves away from the printing drum 100, and the printing drum 100 rotates to set the printing start position again. Then, the elevating unit 103 moves up again, and the cardboard 1 is moved by the printing drum 100 and the press roller 104.
The second printing is performed by rotating the print drum 100 with the “01” therebetween.

[0005]

In screen printing using a flat screen, even when printing is performed on a very small portion of a large cardboard, a large screen having an area capable of covering the entire cardboard is used. A large-scale printing device that can be installed is required.

In the printing apparatus having the above-described printing drum 100, the above-described printing operation cannot be performed if the printing drum 100 is fixedly arranged at a position in contact with the transport surface 102 of the cardboard 101. For this reason, the printing drum 10
0 is fixed at a position above the transport surface 102, and the cardboard 101 is lifted by a press roller 104 that can move up and down below the print drum 100. However, this had the following problems.

That is, as shown in FIG. 8, when a part of the long cardboard 101 is lifted in a strip shape, a step (a) is formed between the cardboard 101 and a part that cannot be lifted due to the weight of the cardboard itself.
Can be done. The step (a) deforms the cardboard 101, and this deformation causes resistance of the cardboard 101 to be conveyed, thereby lowering the conveyance stability. As a result, there is a problem that stable printing cannot be performed.

The present invention has been made to solve the above-described problems. SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing apparatus which can print on a printing material which is thicker than ordinary printing paper and is long in a band shape, such as a cardboard for a developed box, without any trouble.

[0009]

According to a first aspect of the present invention, there is provided a printing apparatus comprising: a conveying unit (conveying roller) configured to convey an object to be printed; and a support contacting a lower surface of the object conveyed by the conveying unit. Means (press roller 4), and a printing drum (5) which is arranged above and below the support means so as to be able to move up and down and which is driven to rotate in contact with the upper surface of the printing medium.

[0010] In the printing apparatus according to the present invention, a transport roller (2) for transporting the printing material (1) along the transport surface (3), and the transport surface adjacent to the transport direction of the transport roller. And a rotatable press roller (4) in contact with the lower surface of the printing medium transported by the transport roller, a peripheral wall (8) on which a plate is mounted on an outer peripheral surface, and a central axis (9) of the peripheral wall. A printing drum (5) that is disposed above the press roller so as to be able to move up and down and that is driven to rotate in contact with the upper surface of a printing material on the press roller; and a drive unit that moves the print drum up and down ( 2
1, a drive cylinder 31, an arm 35, a rack 37, and a pinion 38).

A printing apparatus according to a third aspect of the present invention is the printing apparatus according to the second aspect, wherein the printing apparatus is disposed before the printing drum (5) and the press roller (4) in the transport direction of the printing medium (1). And a thickness sensor (30) for measuring the thickness of the printing medium conveyed by the conveyance roller (2) and outputting a thickness signal. And
The drive means (21, drive cylinder 31, arm 35,
The rack 37 and the pinion 38) are controlled so as to raise and lower the printing drum in response to a thickness signal from the sensor, and to set the interval between the printing drum and the press roller in accordance with the thickness of the printing material. It has become.

According to a fourth aspect of the present invention, in the printing apparatus of the third aspect, a frame (12) for holding the central axis (9) of the printing drum (5), and Guide means (18) for guiding up and down is further provided. The drive means rotates the driven member (roller 22) provided on the frame, a lead cam (23) arranged near the frame and engaged with the driven member, and the lead cam. A drive source (elevation motor 24) for elevating the frame body.

According to a fifth aspect of the present invention, in the printing apparatus according to the third aspect, the driving means includes a cylinder (32) fixed at a predetermined position and the central shaft of the printing drum (5). A drive cylinder (3) having a piston connected to (9) and moving along the cylinder.
1).

According to a sixth aspect of the present invention, in the printing apparatus according to the third aspect, the driving means includes a base supported at a predetermined position and the central shaft (9) of the printing drum (5). And an arm (35) that swings around the predetermined position with a support portion connected to the arm.

According to a seventh aspect of the present invention, there is provided the printing apparatus according to the third aspect, wherein the driving means is provided at a predetermined position and is rotated and driven by a pinion (38) and the printing drum (5). And a rack (37) fixed to the pinion and engaged with the pinion.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printing apparatus according to a first embodiment of the present invention will be described with reference to FIGS. Printed materials 1 such as cardboard are stacked at predetermined positions. The upper print substrate 1 is carried out while being held by the suction device. As shown in FIG. 1, the transport roller 2
Is transported along the transport surface 3. A press roller 4 serving as a support unit that supports the print target 1 from below is provided at an adjacent portion in the transport direction of the transport roller 2. The press roller 4 is rotatable, but its position is fixed. That is, the press roller 4 is rotatably provided at a predetermined position below the transport surface 3 along the transport surface 3, and rotates in contact with the lower surface of the printing material 1 transported by the transport roller 2.

As shown in FIG. 1, a printing drum 5 is arranged above the press roller 4. As shown in FIG. 2, the printing drum 5 has a disk-shaped base member 7 provided with a handle 6 and an ink-permeable peripheral wall 8 rotatably provided with respect to the base member 7. The peripheral wall 8 has a center axis 9 serving as a rotation center. As shown in FIG. 2, a plate fixing device 10 is provided on the outer peripheral surface of the peripheral wall 8 in parallel with the central axis 9. The leading end of the stencil sheet thus formed is fixed to the peripheral wall 8 by the fixing device 10 and wound around the outer peripheral surface of the peripheral wall 8. An ink supply device is provided inside the peripheral wall 8, and supplies ink to the inner surface of the peripheral wall 8.

The printing drum 5 according to the present embodiment can be moved up and down, and is driven to rotate in contact with the upper surface of the printing material 1 on the press roller 4. Here, a structure in which the print drum 5 according to the present embodiment moves up and down will be described with reference to FIGS. As shown in FIGS. 2 and 3, the printing apparatus of the present embodiment has a housing 11. A frame 12 is provided inside the housing 11. The printing drum 5 is rotatably held by the frame 12. If the printing drum 5 is installed at a predetermined position of the frame 12 from the opening 11a of the housing 11 along guide means (not shown), the base member 7 is positioned on the near side in the insertion direction.
The peripheral wall 8 is detachably connected to the drive shaft 14 of the frame 12 on the inner side in the insertion direction. A drive motor 15 is attached to the frame 12. The drive shaft 14 of the frame 12 includes a pulley 16 and a belt 1.
7 to the drive motor 15.

As shown in FIGS. 2 and 4, the frame 12 is
It is guided so as to be able to move up and down inside the housing 11 by the guide means 18. That is, as shown in FIG. 2, the frame 12 is substantially rectangular in plan view, and guide rollers 19 are provided at positions corresponding to two adjacent corners of the rectangle. Further, two groove-shaped guide members 20 are provided inside the housing 11 along the vertical direction, and the respective guide rollers 19 are engaged with the respective guide members 20.

As shown in FIGS. 2 to 4, the frame body 12 is driven up and down by the driving means 21 inside the housing 11.
The driving means 21 includes a roller 22 provided as a driven member provided on the frame 12, a lead cam 23 disposed near the frame 12 and engaged with the roller 22, and rotating the lead cam 23 to move the roller 22 up and down. Elevating motor 24 as drive source
have.

The rollers 22 are respectively provided at positions corresponding to two adjacent corners of the substantially rectangular frame 12. Two cam shafts 25 are provided inside the housing 11 along the vertical direction. These camshafts 25 are rotatable at predetermined positions. The lead cam 23 is a cam spirally provided on these cam shafts 25.
The lower ends of the two cam shafts 25 are connected to a common horizontal drive shaft 27 via a bevel gear 26. The horizontal drive shaft 27 is connected to a lifting motor 24 via a pulley 28 and a belt 29.

As shown in FIG. 1, a thickness sensor 30 is disposed in front of the printing drum 5 and the press roller 4 in the transport direction of the printing material 1. Thickness sensor 3
Numeral 0 detects the upper surface of the print substrate 1, measures its thickness, and outputs a thickness signal. The principle of the thickness sensor 30 is not particularly limited. Any material that can detect the thickness of the print substrate 1 may be used. For example, a sensor using light or ultrasonic waves or a contact-type sensor may be used.

The present apparatus is provided with control means for integrally controlling each section of the present apparatus described above. This control means drives the elevating motor 24 in response to the thickness signal from the thickness sensor 30 to elevate and lower the printing drum 5 so that the distance between the printing drum 5 and the press roller 4 depends on the thickness of the printing material 1. Set. The control unit also controls a printing operation using the printing drum 5 and the press roller 4.

Although not shown, a transport roller set at the same height as the transport surface 3 is provided in front of the printing drum 5 in the transport direction of the print substrate 1 to carry out the printed print substrate 1. It has become.

A printing operation using this apparatus will be described. The printing medium 1 is taken out from a predetermined position, and is conveyed along a conveying surface 3 by conveying means including a conveying roller 2. At this time, the printing drum 5 is at a predetermined position above and away from the transport surface 3. Before the print substrate 1 reaches the print drum 5, the thickness sensor 30 detects the thickness of the print substrate 1 and outputs a thickness signal. The printing material 1 is conveyed by the conveying roller 2 and moves on the conveying surface 3 and enters between the printing drum 5 and the press roller 4 without a change in height. When the printing start position of the printing object 1 and the printing start position between the printing drum 5 and the press roller 4 match in the conveying direction, the conveyance of the printing object 1 is temporarily stopped. The control means drives the elevating motor 24 using the thickness signal, lowers the frame 12, and sets the position of the printing drum 5 in the vertical direction. That is, the interval between the printing drum 5 and the press roller 4 is adjusted to the thickness of the printing material 1. As a result, the printing material 1 is sandwiched between the printing drum 5 and the press roller 4. At this time, the printing drum 5
Has already been set as the print start position in the rotation direction, so that the print start position of the print drum 5 and the print start position of the printing medium 1 match.

The printing drum 5 is driven. The printing material 1 is conveyed while being sandwiched between the printing drum 5 and the press roller 4, and is printed. The height of the printing material 1 being conveyed by the conveyance roller 2 is the same as the height of the printing material 1 being printed by the printing drum 5 and the press roller 4. Therefore, there is no step between the printing target 1 during printing and the printing target 1 before or after printing. Therefore, the printing state of the printing substrate 1 is stable, and the quality of printing is improved.

In the case where the same printing is performed twice or more on one printing medium 1, the following is performed. First, the print drum 5 is raised when the first printing is completed. The printing drum 5 is set again at the printing start position, and the printing medium 1 is conveyed and set at the second printing start position. Thereafter, the printing drum 5 is lowered to start the second printing.

Another example of the driving means for raising and lowering the printing drum 5 will be described with reference to FIGS. The configuration other than the driving means of the printing drum 5 is substantially the same as the first example.

In FIG. 5, the frame on which the printing drum 5 is rotatably mounted is moved up and down by a driving cylinder 31 as driving means. The cylinder 32, which is the main body of the drive cylinder 31, is fixed to the housing 11 of the apparatus. A rod 33 is connected to a piston that slides inside the cylinder 32. This rod 33 is connected to the frame. By operating the drive cylinder 31, the printing drum 5 can be raised and lowered.

In FIG. 6, the arm 3 as the driving means 21
At 5, the printing drum 5 is swung up and down. The base of the arm 35 is fixed at a predetermined position in the device. Arm 35
A frame on which the printing drum 5 is rotatably mounted is attached to the support section. Arm 3 using drive source
By swinging the printing drum 5 up and down, the printing drum 5 can be moved up and down.

In FIG. 7, the printing drum 5 is moved up and down by a rack 37 and a pinion 38 as driving means. A rack 37 is fixed to a frame on which the printing drum 5 is rotatably mounted along a vertical direction. A pinion 38 provided on the housing 11 side of the apparatus is engaged with a rack 37 and is driven to rotate by a drive source. When the pinion 38 is driven to rotate, the printing drum 5 moves up and down together with the frame 12.

[0032]

As described above, according to the present invention, printing is performed by sandwiching a printing material between a press roll provided on a transport surface and a print drum which can be raised and lowered with respect to the press roll. Therefore, there is no step formed on the printing material during printing and during transport, and no extra load is applied to the printing material.
Further, the distance between the printing drum and the press roller is adjusted according to the thickness of the printing medium detected by the thickness sensor. Therefore, the interval between the printing drum and the press roller is always stable. Therefore, according to the present invention, the finished state of printing is stabilized, and the printing quality is improved. The printing apparatus of the present invention

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of a first example of the present invention.

FIG. 2 is a cross-sectional view illustrating a lifting / lowering mechanism of a printing drum in a first example.

FIG. 3 is a vertical cross-sectional view showing a print drum elevating mechanism according to a first example.

FIG. 4 is a front view of an elevating mechanism of the printing drum in the first example.

FIG. 5 is a front view schematically showing the configuration of a second example of the present invention.

FIG. 6 is a front view schematically showing a configuration of a third example of the present invention.

FIG. 7 is a front view schematically showing the configuration of a fourth example of the present invention.

FIG. 8 is a front view showing a problem of cardboard printing in a conventional printing apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 printed material 2 transport roller 3 as transporting means 3 transport surface 4 press roller 5 as supporting means 5 printing drum 8 peripheral wall 9 center axis 12 frame 21 driving means 23 lead cam 24 elevating motor 30 as driving source 30 thickness sensor 31 driving means Drive cylinder 32 cylinder 35 arm as drive means 37 rack as drive means 38 pinion as drive means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Ueda 2-20-15 Shimbashi, Minato-ku, Tokyo R-Science Industry Co., Ltd. F-term (reference) 2C034 AE13 AE22 AE25 AE26 2C250 EA46 EB50 3F048 AA05 AB04 BA06 BB05 CA02 CC02 DA06 DC02 DC11 EB37

Claims (7)

[Claims] A transporting means for transporting the printing medium; a supporting means for contacting a lower surface of the printing medium transported by the transporting means; And a printing drum driven to rotate. 2. A transport roller for transporting an object to be printed along a transport surface, and provided along the transport surface at a portion adjacent to the transport direction of the transport roller and provided on a lower surface of the object transported by the transport roller. A rotatable press roller that comes into contact with a peripheral wall to which a plate is attached on an outer peripheral surface, and a central axis of the peripheral wall. A printing apparatus, comprising: a printing drum that is rotated and driven in contact with the printing drum; and a driving unit that moves the printing drum up and down. 3. A thickness sensor that is disposed in front of the printing drum and the press roller in a transport direction of the printing medium and measures a thickness of the printing medium transported by the transport roller and outputs a thickness signal. Further, the driving unit is controlled to raise and lower the printing drum according to a thickness signal from the sensor, and to set an interval between the printing drum and the press roller according to a thickness of a printing material. The printing apparatus according to claim 2, wherein 4. A frame that holds the central axis of the printing drum, and a guide that guides the frame so as to be able to move up and down, wherein the driving unit is a driven member provided on the frame. The printing apparatus according to claim 3, further comprising: a lead cam disposed near the frame and engaged with the driven member; and a driving source configured to rotate the lead cam to move the frame up and down. 5. The drive unit according to claim 3, wherein the drive unit includes a cylinder fixed at a predetermined position and a piston connected to the central axis of the print drum and moving along the cylinder. Printing device. 6. The driving device according to claim 1, wherein the driving unit is an arm that includes a base that is pivotally supported at a predetermined position and a support that is connected to the central axis of the printing drum, and swings about the predetermined position. 3. The printing device according to 3. 7. The printing apparatus according to claim 3, wherein the driving unit includes a pinion provided at a predetermined position and driven to rotate, and a rack fixed to the printing drum and engaged with the pinion.