JP7109028B2 - support shaft cover - Google Patents

Description

The disclosed technique relates to a support shaft cover that prevents ink smearing around the end of a plate cylinder used in gravure printing.

Generally, in gravure printing, printing is performed using a cylindrical plate cylinder having a plate surface (intaglio plate) on its outer peripheral surface. That is, ink is applied to the plate surface of the rotating plate cylinder by, for example, immersing a portion of the plate cylinder in ink. After scraping off excess ink from the plate surface with a doctor blade, the plate surface is pressed against a continuously conveyed web. By doing so, an appropriate amount of ink adhering to the plate surface is transferred to the web.

Since the plate cylinder is exchanged according to the printing contents, it is supported in a detachable state on the gravure printing machine. There are two types of plate cylinders, one with a shaft and the other without a shaft, depending on the supporting method. A shaft-equipped plate cylinder has a pair of support shafts protruding in opposite directions from both end surfaces of the plate cylinder, and is supported by the gravure printing machine via these support shafts.

On the other hand, a shaftless type plate cylinder has a pair of holes formed in both end faces thereof. By inserting a pair of support shafts provided in the printing machine into these holes, the shaftless type plate cylinder is supported by the printing machine.

Some of the ink scraped off by the doctor blade during printing drips onto the end face of the plate cylinder or scatters from the end of the plate cylinder. As a result, there arises a problem that the periphery of the end portion of the plate cylinder is smeared with ink. Once the ink dries and solidifies, it cannot be easily removed. Therefore, removal of ink stains is a task that requires time and effort. Ink smearing has become a serious problem as the speed of printing has increased.

Particularly in the case of shaftless plate cylinders, a support shaft is provided in the printing press. Therefore, if the support shaft is smeared with ink, the ink smudge must be removed while switching printing, which hinders shortening of the printing switching time. When the ink smear reaches inside the holes in the plate cylinder, it becomes even more difficult to remove.

Under these circumstances, there have been proposed covers for preventing ink stains on the support shafts of shaftless type plate cylinders.

For example, Patent Literature 1 discloses a gravure printing machine in which the base end portion of a rotating shaft that rotates while supporting a shaftless type plate cylinder is housed inside a cylindrical plate cylinder shaft that does not rotate. there is A specific cylindrical cover with a hat-shaped cross section is screwed onto the plate cylinder shaft so as to cover the tip of the rotating shaft, thereby preventing the rotating shaft from being stained with ink.

In Patent Document 2, a sleeve (corresponding to a plate cylinder shaft) that does not rotate is affixed with tape to a cylindrically wound thick paper, and the rotating portion of the support shaft is covered with the thick paper to prevent the support shaft from rotating. A method for preventing ink smearing is disclosed. This method uses cardboard for the cover and is disposable. Therefore, it is cheaper than the method of Patent Document 1.

Japanese Utility Model Laid-Open No. 57-165438 JP 2010-76375 A

In recent years, due to the demand for improved productivity, shortening the print switching time has become an important issue. In gravure printing, usually multiple plate cylinders are used at the same time. Therefore, there is a demand to reduce the time required for switching work, such as cleaning and replacement, which is performed for each plate cylinder when printing is switched, by seconds. Under such circumstances, removal of ink stains is a heavy burden on the operator.

Moreover, the operator wears gloves during the switching work. Therefore, it is difficult to attach and remove the rolled cardboard to the sleeve as in Patent Document 2, and it takes time to attach and detach the cover. In order to properly attach the cover, one end of the cardboard must be cylindrically shaped without any deviation and then in close contact with the end face of the plate cylinder, and then the cardboard must be adhered to the sleeve. As a result, it often needs to be redone, and in reality, it takes time and effort, and there is room for improvement.

Furthermore, when the lower end of the plate cylinder is immersed in ink to adhere the ink to the plate surface, if the outer diameter of the plate cylinder is small, the cover may come into contact with the liquid surface of the ink.

Accordingly, an object of the technology disclosed is to provide a support shaft cover that can appropriately prevent the support shaft from being stained with ink at a low cost and that can be easily attached and detached even when wearing gloves. Another object of the present invention is to provide a support shaft cover that can be used appropriately regardless of the size of the outer diameter of the plate cylinder.

The disclosed technology relates to a support shaft cover attached to a support shaft located on at least one of the drive side and the driven side of a plate cylinder of a gravure printing press.

Each of the support shafts includes a fixed shaft that is coaxially opposed to and spaced from each other in a non-rotatable state, and a fixed shaft that is rotatable and protrudes from the opposite surface of each of the fixed shafts so as to protrude from the plate cylinder. a rotating shaft supporting an end.

The support shaft cover includes a flexible clip that has an arc-shaped cross section and fits on the outer peripheral surface of the fixed shaft, and a flexible clip that is large enough to cover the fixed shaft and the rotating shaft. and a seat of By attaching the sheet to the outer peripheral surface of the fixed shaft and sandwiching the sheet with the clip, the sheet covers the rotation shaft.

That is, according to this support shaft cover, the sheet is rolled up and mounted on the outer peripheral surface of the fixed shaft, and the opening of the clip is expanded and pushed onto the sheet. Thereby, the sheet is supported by the fixed shaft in a state of being appropriately pressed against the outer peripheral surface of the fixed shaft by the clip. The position of the sheet can be easily adjusted so that the sheet can be easily positioned so that the edge of the sheet contacts the end face of the plate cylinder with little clearance.

Inexpensive materials such as cardboard and synthetic resin thin materials can be used for the sheets, so they can be disposable. Therefore, it is possible to effectively prevent the support shaft from being stained with ink at a low cost, and the support shaft can be easily attached and detached even when wearing gloves, thereby improving productivity.

Moreover, with this support shaft cover, it is possible to eliminate the sheet that covers the lower part of the support shaft. Avoid contact with the liquid surface. Therefore, it can be used appropriately regardless of the size of the outer diameter of the plate cylinder.

The support shaft cover is also provided with tapered cone portions narrowed at the tip portions of the rotary shafts, and tapered holes into which the tapered cone portions are fitted, at the end faces of the plate cylinder. The taper cone portion on the drive side is provided with a key that fits in a key groove provided in the tapered hole on the drive side and is positioned in the vicinity of the outer peripheral surface of the fixed shaft on the drive side in the radial direction. The fixed shaft of is provided with an enlarged diameter portion that protrudes radially outward. The rotating shaft may be covered.

In the case of such a plate cylinder and rotary shaft, on the drive side, a key is provided in the tapered cone portion so that the end on the insertion end side protrudes from the end face of the plate cylinder so that the plate cylinder rotates integrally with the rotary shaft. is common. Therefore, when the key is located near the outer peripheral surface of the fixed shaft on the drive side in the radial direction, if the support shaft cover is attached to the outer peripheral surface of the fixed shaft, the edge of the seat may come into contact with the key and flutter.

On the other hand, if an enlarged diameter portion is provided on the fixed shaft on the drive side, and a sheet is attached to the outer peripheral surface of the enlarged diameter portion and sandwiched with a clip, the sheet will move radially outward from the outer peripheral surface of the fixed shaft. held apart. Therefore, contact of the sheet with the keys can be avoided.

The support shaft cover is also provided with a pinch portion extending in a folded manner on the radially outer side of one circumferential end of the clip, and a slit for sandwiching the sheet is formed at the tip of the pinch portion. , may be

In the case of this support shaft cover, the seat can be attached to the clip in advance, so that it can be attached more easily. When applied to a liquid supply type printing machine, it is possible to prevent not only the ink scraped off by the doctor blade but also the ink in the ink pool from scattering and adhering to the support shaft. Therefore, it is possible to further prevent the support shaft from being stained with ink.

According to the disclosed support shaft cover, it is possible to effectively prevent the support shaft from being stained with ink at a low cost.

It is the figure which simplified and showed the main structure of the gravure printing machine. (a) is a direct immersion type printing machine, and (b) is a liquid supply type printing machine. FIG. 4 is a schematic perspective view of a specific example of a plate cylinder and a support shaft; 4 is a schematic cross-sectional view of a specific example of a plate cylinder and a support shaft; FIG. FIG. 4 is a diagram for explaining a support shaft cover attached to a driven shaft; FIG. 4 is a diagram for explaining a support shaft cover attached to a drive shaft; It is a figure for demonstrating the modification of a support shaft cover.

Embodiments of the disclosed technology will be described in detail below with reference to the drawings. However, the following description is essentially merely an example, and does not limit the present invention, its applications, or its uses.

<Gravure printing machine>
(a) and (b) of FIG. 1 show a simplified example of a main part of a main gravure printing machine (also simply referred to as printing machine 1). The printing press 1 shown in (a) is of a type that does not use the furnisher roll 3 (direct immersion type), and the printing press 1 of (b) is of a type that uses the furnisher roll 3 (liquid supply type). The technology disclosed can be applied to both of these printing presses 1 .

The printing press 1 also includes an ink pan 2, a plate cylinder 4, an impression cylinder 5, a doctor blade 6 and the like. The ink pan 2 is a tray-like container. The doctor blade 6 is a long blade-like member. Each of the furnisher roll 3, the plate cylinder 4, and the impression cylinder 5 is a laterally long columnar member. A plate surface (intaglio plate) forming a print pattern is formed on a portion of the outer peripheral surface of the plate cylinder 4 excluding both end portions. All of these are pivotally supported so as to extend substantially horizontally.

During printing, the plate cylinder 4 and the like rotate in a predetermined direction in accordance with the web W that is continuously conveyed. At the time of printing, the doctor blade 6 is moved so that the edge of the doctor blade 6 is pressed against a predetermined portion of the outer peripheral surface of the plate cylinder 4 on the rotating side toward the pressure contact portion with the impression cylinder 5 at a predetermined angle. Positioned relative to plate cylinder 4 .

A predetermined amount of ink is always held in the ink pan 2 during printing. In the case of the direct immersion type, the lower part of the plate cylinder 4 is immersed in the ink. As a result, ink adheres to the outer peripheral surface of the plate cylinder 4 .

On the other hand, in the case of the liquid supply type, the lower portion of the furnisher roll 3 is immersed in ink. A plate cylinder 4 is pressed against the furnisher roll 3 . The peripheral speed of the furnisher roll 3 is set lower than that of the plate cylinder 4 . As a result, an ink pool is formed in the gap above the pressure contact portion between the furnisher roll 3 and the plate cylinder 4 . The ink adheres to the outer peripheral surface of the plate cylinder 4 .

The impression cylinder 5 is arranged above the plate cylinder 4 . During printing, the lower portion of the impression cylinder 5 is pressed against the upper portion of the plate cylinder 4 with the web W sandwiched therebetween. Excess ink adhering to the outer peripheral surface of the plate cylinder 4 is scraped off by a doctor blade 6 . Then, the appropriate amount of ink is transferred to the web W for printing.

A portion of the ink scraped off by the doctor blade 6 drips onto each end surface of the plate cylinder 4 or scatters from the ends of the plate cylinder 4 . Once the ink adheres to the support shaft supporting the plate cylinder 4 and solidifies, it cannot be easily removed. In particular, in the case of the shaftless type plate cylinder 4, since the support shaft is provided in the printing press 1, the ink stains on the support shaft must be removed between printing operations. Therefore, when the support shaft is smeared with ink, it becomes an obstacle to shortening the print switching time.

<Plate cylinder, support shaft>
2 and 3 show specific examples of the plate cylinder 4 provided in the printing machine 1 and support shafts (drive shaft 20 and driven shaft 30) positioned on both the driving side and the driven side thereof. The illustrated plate cylinder 4 is of the shaftless type.

The plate cylinder 4 has a cylindrical main body portion 11 and a pair of disk-shaped end face portions 12, 12 attached so as to block openings at both ends of the main body portion 11. As shown in FIG. The plate cylinder 4 is formed in a hollow columnar shape. A tapered hole 13 is formed in the central portion of each end surface of the plate cylinder 4 . The inner peripheral surface of the tapered hole 13 is inclined (truncated cone shape) so that the inner diameter becomes smaller toward the inside.

A key groove 14 having a rectangular cross section and extending in the axial direction along the inner peripheral surface of the tapered hole 13 is formed at one location in the circumferential direction of the inner peripheral surface of the tapered hole 13 located on the driving side. Note that the outer diameter and length of the plate cylinder 4 are examples. The outer diameter and length of the plate cylinder 4 are changed according to the contents of printing within the allowable range of the printing machine 1 .

A drive shaft 20 and a driven shaft 30 are provided in the printing press 1 . Each of drive shaft 20 and driven shaft 30 has a fixed shaft 40 and a rotary shaft 50 . Each fixed shaft 40 is made of a thin cover-like member formed in a cylindrical shape. Each fixed shaft 40 is installed in the printing press 1 in a non-rotatable state. The fixed shafts 40 on the drive side and the driven side are arranged so as to face each other with a predetermined distance therebetween while being aligned with the substantially horizontally extending axis J. As shown in FIG.

Each rotating shaft 50 is made of a cylindrical member with an outer diameter slightly smaller than that of the fixed shaft 40 . Each rotating shaft 50 is inserted through each fixed shaft 40 so as to be rotatable about the axis J. As shown in FIG. The distal end portion of the rotating shaft 50 protrudes from the facing surface of each fixed shaft 40 , and is provided with a narrowed tapered cone portion 51 that fits into the tapered hole 13 . A taper cone portion 51 located on the drive side is provided with a key 52 that fits into the key groove 14 .

The key 52 extends axially along the outer peripheral surface of the tapered cone portion 51 . In the case of this drive shaft 20 , the outer diameter of the fixed shaft 40 is slightly larger than the outer diameter of the rotating shaft 50 . Therefore, the end portion 52a on the insertion end side of the key 52, which is positioned radially outermost, is positioned in the vicinity of the outer peripheral surface of the fixed shaft 40 on the drive side in the radial direction.

The drive-side rotary shaft 50 is connected to a motor (not shown) installed in the printing press 1 and is rotated by the motor. Each rotating shaft 50 is configured to be able to move forward and backward along the axis J from the opposing surface of each fixed shaft 40, as indicated by the solid line and the phantom line in FIG. Plate cylinder 4 is positioned between drive shaft 20 and driven shaft 30 such that its center coincides with axis J and key 52 fits into keyway 14 .

Then, the drive-side and driven-side rotary shafts 50 are advanced, and each tapered cone portion 51 is fitted into each tapered hole 13, so that each end of the plate cylinder 4 is connected to the driven-side and driven-side rotary shafts. supported by 50. When the plate cylinder 4 is removed from the printing machine 1, the rotary shafts 50 on the driving side and the driven side are retracted. As a result, each tapered cone portion 51 is extracted from each tapered hole 13, and the plate cylinder 4 is separated from each rotating shaft 50 on the driven side and the driving side.

<Support shaft cover>
4A illustrates the support shaft cover 60 attached to the driven shaft 30. FIG. The support shaft cover 60 has a retaining clip 61 and a seat 62 .

The retaining clip 61 is made of an elastically deformable flexible member having a major arc-shaped cross section (arc-shaped whose circumferential length is greater than half of the total circumference). The stop clip 61 is formed so as to fit on the outer peripheral surface of the fixed shaft 40 on the driven side. The retaining clip 61 is made of plastic, metal, or the like having excellent solvent resistance.

The sheet 62 is made of cardboard or a flexible thin synthetic resin material having excellent solvent resistance. The sheet 62 is used after being cut into a size that can cover the fixed shaft 40 and the rotating shaft 50 . The sheet 62 may be reused, but is preferably disposable because it is inexpensive.

As shown in FIG. 4A, the sheet 62 is rolled and mounted on the outer peripheral surface of the fixed shaft 40 so as to cover the upper portion of the rotating shaft 50 . In the illustrated example, the seat 62 is mounted with a cross-sectional arcuate shape. The opening of the stop clip 61 is widened and the stop clip 61 is pushed onto the sheet 62 mounted on the fixed shaft 40 . Then, the sheet 62 is sandwiched between the fixed shaft 40 and the retaining clip 61. - 特許庁

As a result, the sheet 62 is supported by the fixed shaft 40 while being appropriately pressed against the outer peripheral surface of the fixed shaft 40 by the retaining clip 61 . Since the position of the sheet 62 can be easily adjusted, the sheet 62 can be easily positioned so that the edge of the sheet 62 contacts the end face of the plate cylinder 4 with almost no gap. Therefore, even when wearing gloves, the support shaft cover 60 can be properly worn in a very short period of time. Removal is just as easy.

Moreover, the support shaft cover 60 does not cover the lower portions of the support shafts 20 and 30 . Therefore, when applied to the direct immersion type printing machine 1, even if the outer diameter of the plate cylinder 4 is small, the contact of the sheet 62 with the liquid surface of the ink can be avoided.

The sheet 62 may cover the fixed shaft 40 and the rotating shaft 50 all around. That is, by cutting the sheet 62 into a large size, the sheet 62 is wrapped around the outer peripheral surface of the fixed shaft 40 so that a portion of the sheet 62 overlaps in the circumferential direction. Then, the overlapped portion can be sandwiched by the stop clip 61.例文帳に追加

FIG. 4B illustrates the support shaft cover 60 attached to the drive shaft 20. As shown in FIG. A taper cone portion 51 on the drive side has a key 52 . Structurally, the end portion 52a of the key 52 on the insertion end side generally protrudes from the end face of the plate cylinder 4. As shown in FIG. In this drive shaft 20, the end 52a on the insertion end side of the key 52 is located in the vicinity of the outer peripheral surface of the fixed shaft 40 on the drive side in the radial direction. When attached, the edge of the sheet 62 may come into contact with the key 52 and flutter.

Therefore, in the present embodiment, the fixed shaft 40 on the drive side is provided with an enlarged diameter portion projecting radially outward. In the illustrated example, an auxiliary clip 65 is used to provide the enlarged diameter portion. The auxiliary clip 65 is made of the same material as the stop clip 61 described above and has a predetermined thickness. The auxiliary clip 65 is formed so as to fit on the outer peripheral surface of the fixed shaft 40 on the driving side.

As shown in FIG. 4B, an auxiliary clip 65 is attached in advance to the outer peripheral surface of the fixed shaft 40 on the drive side. As a result, an enlarged diameter portion projecting radially outward is provided on the outer peripheral surface of the drive-side fixed shaft 40 . A retaining clip 61 and a seat 62 are then attached to the drive shaft 20 , as is the support shaft cover 60 attached to the driven shaft 30 . However, the stop clip 61 on the drive shaft 20 side is formed so as to fit on the outer peripheral surface of the auxiliary clip 65 .

On the driving side, a rolled sheet 62 is attached to the outer peripheral surface of the auxiliary clip 65 and the sheet 62 is sandwiched between the auxiliary clip 65 and the stop clip 61 . Then, the sheet 62 covers the rotating shaft 50 . The auxiliary clip 65 holds the sheet 62 at a position spaced radially outward from the outer peripheral surface of the fixed shaft 40 . Therefore, contact of the sheet 62 with the key 52 can be avoided.

<Modification>
FIG. 5 shows a modification of the support shaft cover 60. As shown in FIG. The support shaft cover 60 of this modified example is configured to be particularly suitable for the liquid supply type printing machine 1 . In this modified example, the form of the retaining clip 61 is different from that of the above-described embodiment. Since other configurations such as the seat 62 are the same as those of the above-described embodiment, the same reference numerals are used for the same configurations, and the description thereof will be omitted.

A pinch portion 70 is provided at one end in the circumferential direction of the retaining clip 61 of this modified example. The pinch portion 70 consists of a strip-shaped portion extending along the edge of one end of the retaining clip 61 . The pinch portion 70 extends radially outward from one end of the retaining clip 61 in the circumferential direction. A slit 71 for sandwiching the sheet 62 is formed throughout the tip of the pinch portion 70 .

When attaching the support shaft cover 60 , first, the side portion of the sheet 62 is sandwiched between the slits 71 of the pinch portion 70 . Then, the sheet 62 is folded toward the opening of the retaining clip 61 along the pinch portion 70, as indicated by the arrow Y1 in FIG. Further, the sheet 62 is fitted inside the retaining clip 61 so that the sheet 62 is along the pinch portion 70 and the retaining clip 61 .

In such a state, the retaining clip 61 is attached to the outer peripheral surface of the fixed shaft 40 together with the sheet 62 . Specifically, as shown in the lower diagram of FIG. 5, the pinch portion 70 is mounted above the press-contact portion between the plate cylinder 4 and the furnisher roll 33 where the ink pool is formed.

According to the support shaft cover 60 of this modified example, the seat 62 can be attached to the retaining clip 61 in advance, so that it can be mounted more easily. Not only the ink scraped off by the doctor blade 6, but also the ink in the ink pool can be prevented from scattering and adhering to the support shafts 20, 30, so that the support shafts 20, 30 can be further prevented from being stained with ink. .

Note that the support shaft cover according to the technology disclosed is not limited to the above-described embodiments, and includes various other configurations.

For example, in the embodiments, a gravure printing press using a shaftless type plate cylinder was illustrated, but the technology disclosed can also be applied to a gravure printing press using a shafted type plate cylinder. The enlarged diameter portion may be provided directly on the outer peripheral surface of the fixed shaft by increasing the diameter of a portion of the fixed shaft or by assembling another member to the fixed shaft.

1 Gravure printing machine 4 Plate cylinder 20 Drive shaft (support shaft)
30 driven shaft (support shaft)
40 Fixed shaft 50 Rotating shaft 60 Support shaft cover 61 Stop clip 62 Seat 65 Auxiliary clip (enlarged diameter portion)
J axis W web

Claims (3)

A support shaft cover attached to a support shaft located on at least one of the drive side and the driven side of a plate cylinder of a gravure printing machine,
Each of the support shafts
fixed shafts coaxially spaced apart from each other in a non-rotatable state;
a rotating shaft that protrudes from the facing surface of each of the fixed shafts in a rotatable state and supports the end of the plate cylinder;
with
The support shaft cover is
a flexible clip having a major arc-shaped cross section and fitted to the outer peripheral surface of the fixed shaft;
a flexible sheet having a size capable of covering the fixed shaft and the rotating shaft;
has
A support shaft cover that covers at least an upper portion of the rotary shaft with the sheet by attaching the sheet to at least the upper portion of the outer peripheral surface of the fixed shaft and sandwiching the sheet from the upper side with the clip. The support shaft cover according to claim 1,
A narrowed tapered cone portion is provided at the tip portion of each of the rotating shafts, and a tapered hole into which the tapered cone portion is fitted is provided at each of the end faces of the plate cylinder,
The tapered cone portion on the drive side is provided with a key that fits into a key groove provided in the tapered hole on the drive side and is positioned in the vicinity of the outer peripheral surface of the fixed shaft on the drive side in the radial direction,
The fixed shaft on the drive side is provided with an enlarged diameter portion projecting radially outward. A support shaft cover covering the rotation shaft with a sheet. In the support shaft cover according to claim 1 or claim 2,
A pinch portion extending to fold back is provided on the radially outer side of one end in the circumferential direction of the clip,
A support shaft cover, wherein a slit for sandwiching the sheet is formed at the tip of the pinch portion.

Images