JPH0475130B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a screen printing machine for flat surfaces.

An example of a conventional screen printing machine for steel plate is shown in FIG. In the figure, reference numeral 1 denotes a surface plate, on which a steel plate 2, which is a printing medium, is set. A plate frame 3, a screen 4, and a squeegee carrier 5 are arranged above the surface plate 1.
The squeegee carrier 5 includes a squeegee 6, an air cylinder 7 for driving the squeegee, a scraper 8, and an air cylinder 9 for driving the squeegee. Next, the printing process using the above device will be briefly explained. First, a steel plate 2 is set on a surface plate 1, and then a plate frame 3 holding a screen 4 is lowered. Next, the squeegee 6 is moved downward by the air cylinder 7 and pushes the screen 4. In this state, the squeegee carrier 5 moves from the illustrated standby position in the direction A, and printing is performed on the steel plate 2. When the squeegee carrier 5 moves in the direction A and then stops at a predetermined position, the scraper 8 is moved by the air cylinder 9 in the direction shown by arrow C, scraping off the ink remaining on the left side of the squeegee 6 and removing the ink between the squeegee and the squeegee. scoop up. After that, squeegee 6
returns to the top, and with the ink held between the squeegee and the scraper, the squeegee carrier moves in the direction B, returns to its original standby position, and stops. Furthermore, as soon as the squeegee 6 rises, the plate frame 3 also rises and the steel plate 2
will be sent automatically. With this, one printing process is completed. These operations are automatically performed by a control device (not shown). However, as such printing steps are repeated, ink remains at the corner of the screen opposite to the squeegee standby position, as shown by reference numeral 10, and is no longer used effectively. Therefore, in the past, the operator had no choice but to push out the residual ink 10 toward the center using a hand-held scraper. For this reason, even though the printing process is automated, workers are still required. Moreover, when printing on large scales such as steel plate printing, not only does the ink extrusion work require a lot of effort, but it also takes time, making it impossible to shorten the interval between prints, which ultimately makes it difficult to improve printing speed. The disadvantage was that it was limited. In addition, the conventional device includes an ink tank 11, an ink pump 12, and a drive motor 1.
3 and an ink supply hose 14, so that ink can be supplied onto the screen 4.
The drive motor 13 was operated manually. That is, the operator visually judges the ink consumption state on the screen and appropriately starts the drive motor 13 to supply ink. For this reason as well, a worker is required, making it impossible to achieve unmanned printing processes.

The first object of the present invention is to provide an ink extrusion device that automatically extrudes residual ink that accumulates at the corners of the screen, thereby eliminating the need for a worker to extrude the ink and increasing printing speed compared to the past. Our goal is to provide screen printing machines.

A second object of the present invention is to provide a screen printing machine that completely automates the printing process by providing a control device that automatically controls the drive motor of the ink pump in addition to the ink extrusion device described above.

A screen printing machine according to the first invention of the present application includes a scraper that pushes out residual ink at the corners of the screen toward the center, and a cylinder device that reciprocates the scraper, and the cylinder device has a squeegee at or near a standby position. The scraper is controlled according to the position of the squeegee so that the scraper is pushed out at certain times, but retracted at other times.

In addition to the features of the first invention described above, the screen printing machine according to the second invention of the present application has a control device for the drive motor of the ink pump, and the control device includes a preset counter that is incremented by the number of printing steps. ,
a timer that starts measuring time in response to an output signal when the preset counter counts up; and a switch circuit that is disposed between the drive motor and the power source and is closed by the output signal of the preset counter and opened by the output signal of the timer. It is characterized by having the following.

Embodiments of the present invention shown in FIGS. 2 to 6 will be described below. Note that the same parts as in the conventional device shown in FIG. 1 are denoted by the same reference numerals, and explanations thereof will be omitted.

Referring to FIG. 2, an ink extrusion device 15 is provided on the plate frame 3 on the opposite side of the squeegee standby position (the position shown in the figure). The ink extrusion device 15 is connected to the plate frame 3 as shown in detail in FIGS. 3 and 4.
a pair of guide rails 16 fixed to, a holder 18 movably held on the guide rail 16 via guide rollers 17, and a pair of holders 18.
It has a scraper 19 held by the holder 18, and a cylinder device (in this embodiment, an air cylinder) 20 that reciprocates the holder 18. As seen in FIG. 2, the scraper 19 is arranged so as to push out the residual ink 10 on the screen 4 toward the center of the screen.

FIG. 5 shows the air sequence for the air cylinder 20. In the figure, air source 2
1 is connected to an air cylinder 20 via a switching valve 22. The switching valve 22 is operated by pilot pressure, and pilot pressure is supplied to the switching valve 22 via a manual valve 23 and a mechanical valve 24. The mechanical valve 24 is the second
As shown in the figure, it is attached near the squeegee in the standby position, and when the squeegee returns to the standby position, it is activated and moves to the J position (see Fig. 5).

A control device 25 is connected to the drive motor 13 of the ink pump 12 . As shown in FIG. 6, this control device 25 includes a limit switch 26 for detecting the end of one printing process;
6, a timer 28 that starts control based on the output signal when the preset counter 27 counts up, and a switch circuit 29 between the drive motor 13 and the power source. The switch circuit 29 is configured to be closed by a signal from the preset counter 27 and opened by a signal from the timer 28. As mentioned above, the limit switch 26 is for detecting the end of one printing process, and is activated by the squeegee carrier 5 when it returns to its original position, or when the plate frame 3 is raised. It is mounted so that it is operated by the plate frame 3 when it returns to its original position. Note that the limit switch 26 may be activated during the printing process instead of being activated at the end of one printing process.

Referring again to FIG. 2, the ink supply pipe 1
The tip of 4 is fixed to the scraper 19 and is adapted to move together with the scraper 19. With this configuration, ink is always supplied before the scraper, which is convenient. However, the tip of the ink supply pipe 14 is not necessarily connected to the scraper 19.
It does not need to be movable together with the holder, and may be fixed at an appropriate position.

Next, the operation of the above device will be explained. Now, it is assumed that the manual valve 23 in FIG. 5 is in the I position, and the squeegee carrier 5 is in the standby position shown in FIG. In this state, the mechanical valve 24 is in the J position, and the pilot pressure acts on the switching valve 22 via the manual valve 23 and the mechanical valve 24, so that the switching valve 22 is in the F position. Thus, air source 2
The compressed air from 1 causes the piston rod of air cylinder 20 to extend, and the scraper 19 is in the forward position shown in solid line in FIG. The printing process starts from this state. The steel plate 2 is set on the surface plate 1, the plate frame 3 is lowered, and then the squeegee 6 is also moved to the air cylinder 7.
descends due to Next, squeegee carrier 5 is A
direction, and printing on the steel plate 2 is performed. When the squeegee carrier 5 leaves the standby position, the mechanical valve 24 is switched to the K position shown in FIG. 5 by the restoring force of the built-in spring, and the supply of pilot pressure to the switching valve 22 is stopped. Therefore, the switching valve is switched to the G position, and the piston rod of the air cylinder 20 can be retracted. Thus, the scraper 19 is
It retreats in the direction D to the position shown by the two-dot chain line in the figure. This position is a position that does not collide with the squeegee 6 moving in the A direction. When the squeegee 6 finishes printing on the steel plate 2 and stops, the scraper 8 and the squeegee 6 scoop up the residual ink on the screen as in the conventional case, and the squeegee carrier 5 returns to its original position in the B direction. When the squeegee carrier 5 returns to its original standby position, the mechanical valve 24 is switched to the J position, and therefore the switching valve 22 is switched to the F position. Therefore, the piston rod of the air cylinder 20 begins to extend, and the scraper 19 moves in the E direction while scraping the residual ink on the screen, and moves the residual ink toward the center of the screen, and in the next printing process, the squeegee 6 and the scraper 8 and push it out to a suitable position for scooping up. At the same time as the squeegee carrier 5 moves in the B direction, the plate frame 3 rises and the steel plate 2 is sent out. With this, one printing process is completed. Thereafter, similar operations are repeated, and the ink extrusion device 15 is automatically controlled according to the position of the squeegee for each printing process, and the remaining ink is extruded without colliding with the squeegee carrier.

When the manual valve 23 in FIG. 5 is in the H position as shown, the switching valve 22 is always kept in the K position, and the piston rod of the air cylinder 20 is in a retracted state. Therefore, the scraper 19 is always at the position shown by the two-dot chain line in FIG. 2, and does not move regardless of the reciprocating motion of the squeegee carrier 5 in the directions A and B. That is, the ink extrusion device 15 remains inactive.

Next, the ink supply operation will be explained. The end of one printing process is detected by the limit switch 26 shown in FIG. 6, and the output from the limit switch 26 increments the preset counter 27. When the printing process is repeated the number of times preset in the preset counter 27, the preset counter 27 counts up and the switch circuit 29
Close. Thus, the drive motor 13 rotates,
An ink pump 12 supplies ink onto the screen. On the other hand, the timer 28 starts timing at the same time as the switch circuit 29 closes. After the time set in the timer 28 has elapsed, the switch circuit 29 opens and the drive motor 13 stops rotating. Therefore, the drive motor 13 rotates for the time set by the timer 28 to supply a predetermined amount of ink onto the screen. The same operation is repeated thereafter. Thus, the ink pump automatically supplies a predetermined amount of ink determined by the timer 28 for each predetermined number of printing steps set in the preset counter. The settings of the preset counter 27 and timer 28 are determined appropriately based on the amount of ink consumed in one printing process.

In the above embodiment, the mechanical valve 24 occupies the J position when the squeegee carrier 5 is in the standby position, and immediately switches to the K position when the standby position leaves.
The switching may occur when the squeegee carrier 5 leaves the vicinity of the standby position. Also,
An electromagnetic switching valve may be provided in place of the mechanical valve 24, and the position of the squeegee carrier may be detected by a limit switch, a proximity switch, etc., and the electromagnetic switching valve may be switched.

As explained above, in the present invention, an ink extrusion device is provided to expel the residual ink on the screen toward the center of the screen, and this is automatically controlled according to the position of the squeegee (specifically, the squeegee carrier). There is. Therefore, the ink extrusion work, which was conventionally performed manually, is no longer necessary. In addition, the ink extrusion work is performed while the squeegee moves backward in direction B and then in direction A. Conventional manual work required this time interval of about 12 seconds, but in the present invention, this time interval is 8 seconds.
It can be shortened to about seconds. Therefore, the present invention is also useful for improving printing ability. Further, in the present invention, a predetermined amount of ink is automatically supplied every predetermined number of times of printing. Therefore, unlike the conventional method, a worker is not required for ink supply. In this way, complete automation of screen printing machines was achieved, and unmanned operation became possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing a conventional screen printing machine, FIG. 2 is a schematic side view showing an embodiment of the present invention, and FIG. 3 is a top view of an ink extrusion device used in the device shown in FIG. 4 is a side view of the same, FIG. 5 is a diagram showing the air sequence for the air cylinder of the ink extrusion device, and FIG. 6 is a block diagram of the control device for the drive motor of the ink pump. 2... steel plate, 3... plate frame, 4... screen,
5... Squeegee carrier, 6... Squeegee, 10
...Residual ink, 12...Ink pump, 13...
... Drive motor, 15 ... Ink extrusion device, 1
9...Scraper, 20...Air cylinder, 24
...Mechanical valve.

[Claims]

1. In a recording apparatus having an ink jet head having an ejection nozzle and a cap means for sealing the periphery of the nozzle of this head, an ink absorber for absorbing ink leaking from the nozzle is provided inside the cap means, and a volume is provided in the ink absorber. An inkjet recording device characterized by being provided with means for squeezing out ink by applying a change. 2. The inkjet recording apparatus according to claim 1, wherein the ink absorber is swingably provided so as to be able to come into contact with the head only when absorbing ink.

Claims (1)

The ink pump is controlled in response to the ink pump, and is further provided with a control device for the drive motor of the ink pump. A screen printing machine comprising: a timer that starts counting in response to a signal; and a switch circuit disposed between the drive motor and the power source, which closes when the output signal from the preset counter is received and opens when the output signal from the timer is received. .