JP2785555B2 - Ink return device for screen printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved structure of an ink return device for a screen printing machine.

[0002]

2. Description of the Related Art In a screen printing machine, a squeegee is slid on a screen printing plate, and ink placed on the screen printing plate is extruded through a screen to perform printing on a printing material. Also, after printing while running the squeegee, it is necessary to form a uniform thin film of ink on the screen printing plate before performing the next printing. This is done using a scraper that is arranged in parallel and travels with the squeegee.

FIG. 18 is a view for explaining a conventional ink returning operation. As shown in FIG. 18A, at the time of printing, the scraper 3 is lifted from the printing plate 6, and only the squeegee 4 travels together with the squeegee 4 while sliding on the printing plate 6 in the direction of the arrow, and the ink is applied to the printing substrate. Transfer occurs. When printing is completed, as shown in FIG.
Is lifted off the plate, and the squeegee 4 and the scraper 3 move on the plate in a state where the scraper 3 is lowered, and ink is returned. By this ink returning operation, the ink reservoir 18 is returned to the printing start position of the squeegee 3, and a uniform thin film of ink is formed on the printing plate.

[0004]

As described above, when the squeegee 4 and the scraper 3 are alternately pulled up to perform printing and ink return, when the ink is returned by the scraper, the scraper 3 travels forward. The raised squeegee 4 is located and travels together with the scraper 3 (FIG. 18B). However, squeegee 4
Has a relatively large amount of ink attached thereto during printing, and this ink may drop onto the printing plate in front of the scraper 3 during running when returning the ink. The ink attached to the squeegee 4 is slightly different from the ink in the ink fountain 18 in conditions such as a dry state. Therefore, when the ink is dropped from the squeegee 4, the ink film thickness and the viscosity of the other portions are printed on the printing plate at the dropped portion. Are different from each other. By running the scraper 3, the ink in this portion is also made uniform to some extent, but it cannot be made completely uniform with other portions. Produces uneven ink. For this reason, when printing is performed next time, uneven printing or a difference in print density occurs, and the product quality may be significantly impaired. Also adheres to squeegee 4
Even if the ink does not drop directly onto the plate,
During the ink return, the ink pool in front of the scraper 3
Ink drops when dropped on the ink)
The ink supplied to the plate without being mixed well with the ink
In some cases, product quality may be impaired as well.
You.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a product which prevents ink adhering to a squeegee from dripping on a screen printing plate or ink returned by ink return when the ink is returned by a screen printing machine. It is an object of the present invention to provide an ink return device capable of improving the quality of ink.

[0006]

According to the present invention, a scraper arranged in parallel with a squeegee is reciprocated with the squeegee, and at the time of printing, the scraper is raised so that only the squeegee is slid on the screen printing plate to perform printing. ,
When returning ink, raise the squeegee and slide only the scraper on the screen printing plate to return the ink.In the ink return device of the screen printing machine, when returning the ink, intervene between the raised squeegee and the screen printing plate. Ink from the squeegee
An ink return device for a screen printing machine is provided , wherein a plate-shaped ink receiving member is provided to separate the ink from the returned ink .

[0007]

When printing is completed, the squeegee is pulled up, and when the ink is returned using the scraper, a plate-shaped ink receiving member is inserted between the squeegee and the printing plate, or the squeegee is retracted above the ink receiving member. An ink receiving member is interposed between the squeegee and the printing plate surface. As a result, the ink dripping from the squeegee during ink return is received by the ink receiving member and may drop onto the screen printing plate.
Do not mix with ink returned by ink return
No.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 show a first embodiment of the present invention. 1 and 2, reference numeral 15 denotes a traveling block 14.
Shows a travel guide when moving in parallel with the screen printing plate 6. A printing block 10 to which a squeegee 4, a scraper 3, and the like are attached is fixed to a traveling block 14 that moves on a traveling guide 15 by a drive source (not shown). Air cylinders 16a, 1 for moving the scraper 3 and the squeegee 4 up and down are provided above the printing block 10, respectively.
6b is fixed. Rod 1 of air cylinder 16a
a is connected to an arm 2a having a clamper 17a,
A scraper 3 for returning ink is detachably mounted on the clamper 17a. Similarly, air cylinder 1
Arm 2 having clamper 17b on rod 1b of 6b
The squeegee 4 is detachably attached to the clamper 17b so as to form a predetermined angle with respect to the printing plate 6.

In this embodiment, the air cylinders 16a, 16b
During printing, the scraper 3 is raised and the squeegee 4 is lowered, and the travel block 14 is moved in the direction of the arrow to perform printing with the squeegee 4 (FIG. 2).
Also, when returning the ink, raise the squeegee 4 on the contrary,
With the scraper 4 lowered, the traveling block 14 is moved in the direction opposite to the printing direction to form a uniform ink thin film on the printing plate (FIG. 1). Reference numerals 18 in FIGS. 1 and 2 denote ink pools formed in front of the scraper 3 and the squeegee 4 at the time of ink return and printing, respectively.

In this embodiment, a plate-shaped ink receiver 5 is provided on the side surface of the scraper 3 on the squeegee 4 side.
The ink receiver 5 is made of a resin such as polypropylene or a metal flake.
It is made of a material that is flexible and has good stability after deformation.
As shown in FIG. 3, it is fixed to the side surface of the scraper 3 via a holder 19 with bolts. As shown in FIG. 3B, the ink receiver 5 is attached parallel to the printing plate 6 or inclined such that the tip 5a is slightly higher than the scraper attachment portion. The ink receiver 5 is a squeegee 4
The tip 5a has a sufficient length so that the tip 5a protrudes beyond the portion immediately below the tip of the squeegee 4 in a state in which the squeegee 4 is raised.

Therefore, as shown in FIG. 1, when the ink is returned, the ink 7 dripped from the tip of the squeegee 3 is supplied to the ink receiver 5.
It is received on the upper surface, on the screen printing plate 6 and ink return
Does not fall into the ink returned by . After the ink return, when printing is performed, the squeegee 4 is lowered and the scraper 3 is raised. At this time, the ink receiver 5 comes into contact with the squeegee 4 and bends downward as shown in FIG.
The squeegee 4 is bent along the side surface.

For this reason, the squeegee 4 can slide on the printing plate to perform printing. Further, since the ink receiver 5 is warped along the side surface of the squeegee 4 as described above, the ink that has dropped from the squeegee 4 and adhered to the upper surface of the ink receiver 5 is returned to the ink reservoir along the side surface of the squeegee 4. You. This ink is squeegee 4
Mixing with the ink on the printing plate scraped off by the squeegee 4
And the scraper 3 at the next ink return
Because the ink is stirred and mixed, the ink in the ink pool is uniform
State. For this reason, in this embodiment, the print quality is impaired.
It is possible to use ink efficiently without using ink.

When the ink is returned after the printing is completed, the ink receiver 5 returns to the state shown in FIG. 1 due to the good restoring characteristics with the rise of the squeegee 4, so that the ink return operation by the scraper 3 is obstructed. There is no. Next, FIGS. 4 to 6 show a second embodiment of the present invention. In the above embodiment, the ink receiver 5 is made of a flexible material, and is deformed along the side surface of the squeegee 4 by the elasticity of the ink receiver 5 itself.
It differs in that it is made of a rigid material (for example, stainless steel or an aluminum alloy) and that the scraper mounting portion has elastic restoring force.

FIG. 6 shows the details of the mounting portion of the scraper 3 of the ink receiver 8. In this embodiment, the ink receiver 8 is not directly attached to the scraper 3, but is attached to a detachable plate 20 separate from the scraper 3 via a spring hinge 9.
Further, the holder 21 is formed on the scraper 3 over the entire width of the detachable plate 21 in the width direction. The detachable plate 20 is shown in FIG.
As shown in (B), the cross section has an inverted U-shape,
A spring hinge 9 is attached to one leg of the inverted U-shape, and the other leg is easily detachably fixed to the scraper 3 by inserting the other leg into a groove formed between the holder 21 and the side surface of the scraper 3 from above. Is done.

The spring hinge 9 urges the ink receiver 8 to rotate clockwise in FIG. 6B by the force of the spring housed therein. Similarly, the ink hinge 8 is actuated by the action of a stopper provided inside. Reference numeral 8 does not rotate upward from a predetermined position substantially parallel to the plate surface. FIGS. 4 and 5 are views corresponding to FIGS. 1 and 2, respectively, showing the operations of the ink receiver 8 during ink return and printing. As in the embodiment of FIGS. 1 to 3, at the time of printing (FIG. 5), the ink receiver 8 is used.
Is pushed by the squeegee 4 and tilts along the side surface of the squeegee 4, but when the ink is returned (FIG. 4), the spring hinge 9
The squeegee 4 returns to the position shown in FIG.
To prevent the ink from dropping onto the printing plate 6 or onto the ink returned by the ink return .

FIGS. 7 and 8 are diagrams for explaining a third embodiment of the present invention. Also in this embodiment, the ink receiver 8 is shown in FIG.
6, the rigid plate 8 and the spring hinge 9 are used as in the embodiment of FIG.
Is different in that a mechanism for displacing downward is separately provided. That is, in this embodiment, the rod 11 is fixed to the printing block 10, and when the scraper 3 is raised during printing (FIG. 8), the rod 11 comes into contact with the ink receiver 8, and the ink receiver 8 and the squeegee 4 The ink receiver 8 is tilted downward before the contact is made. When the ink return is performed after the printing is completed (FIG. 7), the ink return 8 returns to the original position as the scraper 3 moves down in the same manner as in the embodiments of FIGS.

According to this embodiment, since the ink receiver 8 and the squeegee 4 do not come into contact with each other, it is possible to completely eliminate the possibility that the squeegee 4 is damaged by the contact with the ink receiver 8. FIGS. 9 to 11 show examples of changes in the shape of the ink receiver 8 used in the embodiment shown in FIGS. 4 to 6, and FIGS.

FIG. 9 shows an example in which, when the tip of the ink receiver 8 is bent upward to return the ink, the ink dropped on the upper surface of the ink receiver 8 does not fall onto the printing plate from the tip of the ink receiver 8. FIG. 10 shows an example in which the ink receiver 8 is inclined downward from the center toward both ends so that the ink dropped on the ink receiver 8 flows into the ink reservoirs at both ends of the scraper 3.

FIG. 11 shows an example of the shape of the ink receiver 8 having the features of both FIG. 9 and FIG. Next, FIG.
FIG. 3 shows a fourth embodiment of the present invention. FIGS. 12 and 13 show a state at the time of ink return and a state at the time of printing, respectively.
2 (A) and 13 (A) are print blocks 10 for clarity,
12 (B) and 13 (B) are overall side views with the traveling block 14 and the traveling guide 15 removed.

In this embodiment, the printing plate 6 is attached to the printing block 10.
The air cylinder 22 is fixed in parallel to the vehicle and at right angles to the traveling direction. The ink receiver 13 is a scraper 3
Instead, it is attached to the rod 12 of the air cylinder 22, and the air cylinder 22 is actuated to enter and exit directly below the squeegee 4. That is, in this embodiment, the ink receiver 13 is retracted to the side of the squeegee 4 during printing (FIG. 13) and returns when ink is returned (FIG. 1).
Only in 2), the ink is inserted just below the squeegee 4 and receives ink dripped from the squeegee 4.

FIGS. 14 to 16 show a fifth embodiment of the present invention. In this embodiment, as shown in FIG.
Reference numeral 8 is integrally fixed to the scraper 3 by bolts or the like. FIG. 17B shows a cross section of the ink receiver 28. The ink receiver 28 formed of a rigid plate is attached to the printing plate at an angle such that the front end side is slightly higher.

In this embodiment, the squeegee 4 is mounted on the rod 1b of the air cylinder 16b.
Has been attached through. Squeegee swing mechanism 30
Are a swing arm 25 rotatably attached to the rod 1b via a pin 24 and a guide groove 27 provided in the printing block 10, and a guide groove fixed to the swing arm 25 and engaged with the guide groove 27. A guide pin 26 is provided so as to be slidable in the inside 27. The guide groove 27 is provided so as to be inclined so that the upper end approaches the scraper 3 side with respect to the moving direction of the rod 1b (perpendicular to the plate).

FIG. 15 is an overall side view of the printing press at the time of printing, FIG. 14A is an enlarged side view of the printing block 10 in FIG. 15, and FIG. 14B is an enlarged front view. As can be seen from FIG. 14A, the air cylinder 1 is used at the time of printing.
Since the rod 1b of 6b descends and the guide pin 26 is located at the lower end of the guide groove 27, the swing arm 25 is perpendicular to the plate and the squeegee 4 contacts the plate at a predetermined angle. .

Printing is performed by running the printing block 10 in this state. When the printing is completed, the squeegee 4 is raised together with the scraper 3 being lowered.
FIG. 16 shows a state in which the squeegee 4 is pulled up.
When the rod 1b is raised by the air cylinder 16b,
The swing arm 25 connected to the rod 1b via the pin 24 moves up together with the rod 1b. At this time, the guide pin 26 fixed to the swing arm 25 is
Swing arm 25 rotates around the guide pin 24 toward the scraper 3. Therefore, the squeegee 4 attached to the tip of the swing arm 25 rises in an oblique direction and moves to a position immediately above the ink receiver 28 attached to the scraper 3. As a result, the ink dropped from the squeegee 4 falls on the upper surface of the ink receiver 28, and
When performing ink return in the condition of 6, on the printing plate or ink return
It does not fall into the returned ink .

In the above-described embodiment, by changing the shape of the ink receiver as shown in FIG. 9 to FIG. 11 or FIG. 17 (B), the ink dropped on the ink receiver can be printed in the printing range (FIG. 17 (A)). (See Reference.) Flow down to both ends of the outer scraper 3. As a result, the ink dropped from the squeegee 4 is mixed with the ink in the ink fountain 18 at both ends of the scraper 3 outside the printing range, and is supplied to the printing range after being completely mixed. Non-uniform viscosity of the ink in the ink pool is prevented.

[0026]

According to the present invention, as described above, the ink adhered to the squeegee during ink return can be applied to the printing plate or the ink return without complicating the mechanism of the printing press.
The quality of printing can be improved by preventing dripping on the returned ink .

[Brief description of the drawings]

FIG. 1 is a side view showing a state at the time of ink return of a first embodiment of an ink return device of the present invention.

FIG. 2 is a side view showing a printing state of the embodiment.

FIG. 3 is a diagram showing details of an ink receiver of the embodiment.

FIG. 4 is an enlarged view of a main part showing a state at the time of ink return of a second embodiment of the ink return device of the present invention.

FIG. 5 is an enlarged view of a main part showing a state at the time of printing in the embodiment.

FIG. 6 is a diagram showing a detailed line of an ink receiver of the embodiment.

FIG. 7 is a side view showing a state at the time of ink return of a third embodiment of the ink return device of the present invention.

FIG. 8 is a side view showing a state at the time of printing in the embodiment.

FIG. 9 is a diagram showing an example of the shape of an ink receiver used in the second embodiment and the third embodiment.

FIG. 10 is a diagram showing an example of the shape of an ink receiver used in the second embodiment and the third embodiment.

FIG. 11 is a diagram showing an example of the shape of an ink receiver used in the second embodiment and the third embodiment.

FIG. 12 is a partially omitted plan view (A) and a side view (B) showing a state at the time of ink return in a fourth embodiment of the ink return device of the present invention.

FIG. 13 is a partially omitted plan view (A) and a side view (B) showing a printing state of the embodiment.

FIG. 14 is an enlarged side view (A) and a front view (B) of a main part of a fifth embodiment of the ink return device of the present invention.

FIG. 15 is a side view showing a state at the time of printing in the embodiment.

FIG. 16 is a side view showing a state at the time of ink return in the embodiment.

FIG. 17 is a diagram showing details of an ink receiver of the embodiment.

FIG. 18 is a diagram illustrating an ink return operation by a conventional ink return device.

[Explanation of symbols]

 1a, 1b rod 2 arm 3 scraper 4 squeegee 5, 8, 13, 28 ink receiver 6 screen printing plate 7 dripping ink 9 spring hinge 10 printing block 11 rod 14 traveling block 15 traveling Guides 16a, 16b Air cylinder 18 Ink reservoir 21 Holder 22 Air cylinder 24 Pin 25 Swing arm 26 Guide pin 27 Guide groove 30 Squeegee swing mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-270159 (JP, A) JP-A-62-132643 (JP, A) JP-A-1-59628 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) B41F 15/40-15/46

Claims (1)

(57) [Claims] 1. A scraper arranged in parallel with a squeegee is reciprocated along with the squeegee, and the scraper is raised at the time of printing so that only the squeegee is slid on the screen printing plate, and the squeegee is raised at the time of ink return. In the ink return device of a screen printing machine that performs ink return by sliding only on the screen printing plate, when ink is returned, it is interposed between the raised squeegee and the screen printing plate and dropped from the squeegee
Separates ink from ink returned by ink return
And a plate-shaped ink receiving member.