JPS6014586Y2 - Doctor device of pad printing machine - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement on the doctoring device of a pad printing machine, in which the reciprocating direction of the doctor head with respect to the printing plate in the ink tray can be changed according to the shape of the ink pocket on the printing plate surface. It is something to consider.

By the way, in a pad printing machine that uses an intaglio printing plate, in order to apply the necessary amount of ink to the printing plate surface,
A doctor device is equipped with a brush or roller for applying ink and a blade for scraping ink, and after first applying more than the required amount of ink to the printing plate surface with a brush, etc., excess ink is removed from several sides with a blade. It is customary to scrape it off with a
(See Publication No. 5).

In addition, a squeegee may be used instead of the brush and blade described above, and the squeegee may be used to apply ink and scrape off excess ink.
(Refer to Publication No.-52813).

However, the above-mentioned blade is made of a thin metal plate with high spring elasticity, and its tip is kept in pressure contact with the printing plate surface by the restoring elasticity based on the elastic deformation when it is pressed against the printing plate. Depending on the shape and direction of the ink pocket recessed into the printing plate surface, undesirable situations may occur.

That is, when the ink pockets are continuous in the form of a long and narrow groove, the ink pockets 7 are formed as shown in FIGS. 3A and 3B, for example.
If the length direction is not parallel to the width direction of the blade 11, and therefore the width W across the ink pocket 7 of the blade is small, the tip portion of this blade is shown slightly exaggerated in Figure B. As shown in FIG. 3, the blade remains elastically deformed and its tip does not enter into the ink pocket 7, so there is no risk that the ink 36 in the pocket will be scraped out by the blade tip. As shown in FIGS. 4A and 4B, if the length direction of the ink pocket 7 is parallel to or close to the width direction of the blade 11, and therefore the width W across the ink pocket 7 of the blade is large, In order to restore the tip portion from the above-described elastically deformed shape and insert the tip into the ink pocket 7,
The ink 36 in the pocket is scraped out by the tip of the blade, resulting in a shortage of ink, resulting in a situation where the printing by the pad on the printing surface becomes unclear.

Further, such a situation similarly occurs when the above-mentioned squeegee is used.

The present invention addresses the above-mentioned conventional problems and prevents the ink inside the pocket from being scraped out by the tip of the blade even when the printing plate has an elongated groove-shaped ink pocket. In order to achieve this, the reciprocating direction of the doctor head equipped with this blade can be freely changed according to the length direction of the ink pocket.

Hereinafter, an embodiment shown in the drawings will be described in detail.

In the figure, reference numeral 1 denotes a pad printing machine stand, and a support stand 3 for a workpiece 2, which is a printing material, is fixed at the front upper part of the machine stand, and a plate holder 4 is placed behind this support stand 3. An ink tray 5 is fixed therebetween.

Reference numeral 6 denotes a printing plate fixed in the above-mentioned ink tray 5, which is usually an intaglio plate, and therefore has ink pockets 7 recessed in its surface as illustrated in FIGS. 3 and 4, for example. There is.

8 is a highly elastic pad as an ink medium,
While supported by a known suitable support mechanism (not shown),
It is assumed that it is made to reciprocate between a position above the work 2 and a position above the printing plate 6, and to be raised and lowered between the respective above positions to the work 2 and the printing plate 6.

However, the illustrated pad printing machine is intended for a workpiece 2 whose horizontal width is larger than its front-to-back width, and therefore the ink tray 5, printing plate 6, and pad 8 are also made to have larger horizontal widths.

Reference numeral 9 denotes a head of a doctor device according to the present invention, which includes a brush 10 for applying a wide range of ink and a blade 11 for scraping off ink.

Reference numeral 12 denotes a base of the doctor device, and its upper surface includes a guide means for guiding the doctor head 9 horizontally above the ink tray 5 along the plate surface of the printing plate 6, and a guide means for guiding the head in a reciprocating manner. A drive means is provided for causing the movement.

As an example of such a guide means, an ink tray 5 is shown in the illustrated example.
A horizontal guide shaft 13 extending along the outer upper side of one of the sides is attached to the doctor base 12 using a bracket 14, 15, and a slide block 16 is provided that is slidable along the shaft. , the doctor head 9 is supported by the block via one end of its frame 17.

In addition, as an example of a driving means, the illustrated example shows a fluid pressure cylinder 1.
8 is used, and the cylinder is attached to one of the brackets 15
The tip of the plunger 19 is connected to the slide block 16 while the plunger 19 is attached to the slide block 16.

In such a doctor device, in order to be able to freely change the reciprocating direction of the doctor head 9 from the front-rear direction to the left-right direction, the above-mentioned guide means and drive means of the doctor head 9 must be changed in their respective guide directions and drive directions. Both need to be able to be changed freely.

Therefore, in the illustrated example, in order to use the tray holder 4 on the machine base 1 as a turning fulcrum, several units are formed into a circular shape, for example, and the doctor base 12 is placed around the tray holder on the machine base. It is rotatable and can be appropriately fixed onto the machine base using fixing means such as screws or clamps (not shown).

In addition, since the stamp plate 6 in the illustrated example has a horizontal width that is smaller than the front-rear width, the stroke of the doctor head 9 that reciprocates on the printing plate is determined whether the reciprocating direction of the head is the front-rear direction or the left-right direction. It is necessary to adjust depending on the

Therefore, in the illustrated example, a movable stopper 20.21 at a fixed position is attached to the guide shaft 13 as a simple stroke adjustment means, and the range in which the slide block 16 can slide is regulated according to the required stroke. It is now possible to do so.

Furthermore, when the reciprocating direction of the doctor head 9 is changed,
The widths of the brush 10 and blade 11 described above also need to be changed in accordance with the left-right width or front-back width of the printing plate 6, so the brush 10 and blade 11 can be replaced with ones of different widths at any time.

A specific example of the structure of the doctor head 9 is as shown in FIG.

- That is, the brush 10 is supported by a brush par 23 via a brush holder 22, and is attached to a fluid pressure cylinder 2 attached to the head frame 17 via a bracket 24.
It can be raised and lowered by a plunger 26 of No. 5.

The blade 11 is held between a blade holder 27 and a blade presser 28 and supported by a blade base 30 via a blade par 29, and is supported by a bell crank supported by the head frame 17 via a pivot 31. 3
2, and a bracket 33 is attached to the frame.
The plunger 3 of the hydraulic body cylinder 34 supported via
It can be raised and lowered at 5.

Further, numeral 36 in the figure is ink stored in the ink tray 5.

In the above-described configuration, it is assumed that the pad 8 is located at the front and the doctor head 9 is located at the rear of the ink tray 5, as shown in FIGS.

In this state, the blade 11 is raised to a position higher than the plate surface of the printing plate 6 as shown in FIG. After raising the doctor head 9 to a position higher than the plate surface of the printing plate 6, the entire doctor head 9 is moved forward to the front of the ink tray 5.

Next, the blade 11 is lowered to a height such that its tip is brought into pressure contact with the plate surface of the printing plate 6, and the brush 10 is also lowered.
The doctor head 9 is lowered to a height where it can be rubbed on the plate surface, and the entire doctor head 9 is moved back to the rear of the ink tray 5 again.

Then, more than the required amount of ink is first applied to the surface of the printing plate 6 by the brush 10, and then the excess ink is scraped off by the blade 11, leaving ink only in the ink pocket 7.

Therefore, the pad 8 located above the front of the ink tray 5 is moved above the printing plate 6 and then lowered so as to press against the plate surface.

Then, the ink in the ink pocket 7 is deposited on the lower surface of the pad 8.

After that, when this pad 8 is raised, then returned to the front again, and then lowered to press it against the upper surface of the workpiece 2, the ink adhering to the pad is transferred to the upper surface of the workpiece, where - Pad printing will be completed once.

In such pad printing, even if the ink pockets 7 on the printing plate surface have a continuous elongated groove shape, the length direction is not parallel to the width direction of the blade 11, for example, the first
If they are orthogonal as shown by the solid lines in the figure, or in a state close to this, the blades 1
Since the width W across the first ink pocket 7 is small, there is no risk that the tip of the blade will enter the pocket.

However, if the length direction of this elongated ink pocket 7 is parallel to or close to the width direction of the blade 11 as shown by the chain line in FIG.
, B, the width W of the blade 11 across the ink pocket 7 becomes large, so the tip of the blade enters into the pocket and scrapes out the ink 36 in the pocket, causing an ink shortage situation.

Therefore, when there is an elongated ink pocket 7 on the plate surface of the printing plate 6 and the length direction of this pocket is parallel to or close to the width direction of the blade 11, it is indicated by a chain line in FIG. As shown in FIG. 1, the doctor base 12 is rotated 90 degrees clockwise in FIG. The drive means including the cylinder 18 and the like and the entire doctor head 9 supported by the guide means are also turned as shown by the chain lines.

Then, the reciprocating direction of the doctor head 9 is changed from the previous front-rear direction to the left-right direction with the printing plate 6 as the de facto center of rotation, so that the ink pocket 7 length direction and the blade 11
The width direction of the blade is perpendicular to or close to the width direction, so there is no possibility that the tip of the blade will enter the ink pocket 7.

Note that the changing angle of the reciprocating direction of the doctor head 9 is not limited to the above-mentioned 90 degrees, but can also be set to, for example, 45 degrees, so that it can be set optimally according to the length direction of the ink pocket 7. Please select as appropriate.

In any case, when the reciprocating direction of the doctor head 9 is changed, it is necessary to adjust its stroke accordingly, and in the illustrated example, this adjustment is performed by displacing the fixed position of the stopper 20, 21. .

Also, along with this adjustment, the brush 10 and blade 11
If the widths do not match, you can replace them with ones of the required width.

As described above, the present invention allows the reciprocating direction of the doctor head to be freely changed in the doctor device of a pad printing machine, so even when there are elongated groove-shaped ink pockets on the printing plate surface, The doctor head can be moved back and forth in the most suitable direction according to the length direction of the pocket, and when scraping excess ink from the printing plate surface with the blade, the tip of the blade does not enter the ink pocket. Therefore, the situation in which the ink pocket runs out of ink can be effectively avoided, and the effect that printing on the printing surface by the pad can always be made clear can be expected.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view thereof, and Fig. 3A is a partially cutaway front view showing a preferred state of scraping off excess ink. B is a sectional view taken along line I-I in Figure A, FIG.
FIG. 5 is an enlarged sectional view taken along line -■ in FIG. 1. 1...Machine base, 4...Plate holder, 5...
...Ink tray, 6...Print plate, 7...
Ink pocket, 8...Pad, 9...
・Doctor head, 10...Brush, 11...
...Blade, 12...Doctor Base,
13... Guide shaft, 16... Slide block, 18... Fluid pressure cylinder, 19...
...Plunger, 36...Ink.

Claims (1)

[Scope of utility model registration request] An ink tray fixed on the machine table via a tray holder, a printing plate fixed in the tray, a brush for applying ink to the plate surface of the printing plate, and a blade for scraping excess ink from the plate surface. In a pad printing machine equipped with a doctor head that is to be reciprocated along the plate surface, there is a doctor base on the machine stand that can be rotated around a plate holder, and on this doctor base there is a A horizontal guide shaft is attached along the outer upper side of one of the sides of the ink tray, the doctor head is supported by a slide block on the shaft, and a fluid pressure control shaft is also attached to the doctor base. A doctor device for a pad printing machine, characterized in that a plunger tip of a cylinder is connected to its slide block.