JPH011543A - Printing pattern correction device for screen printers - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Object of the Invention (Field of Industrial Application) The present invention is to synchronize the reciprocating back and forth motion of the screen plate and the reciprocating rotation motion of the circumferential surface, and to provide a screen that performs this synchronized reciprocating motion. A method of printing patterns in a screen printing machine, which prints by feeding printing paper between a plate and a circumferential surface and pressing the screen plate at a predetermined position with a squeegee to push the ink on the screen plate onto the printing paper. This invention relates to a correction device.

(Prior Art) This type of screen printing machine, for example, supplies ink and water onto a plate-making cylinder while uniformly mixing them through a plurality of cylinder rows, and reversely copies the printing pattern on this plate-making cylinder onto a plan cylinder. The mechanism is much simpler than offset printing, which prints by

(Problems to be Solved by the Invention) However, offset printing allows multicolor printing at the expense of complicating the mechanism, but multicolor printing is not possible with conventional screen printing machines. That is, in screen printing, it is not possible to move on to printing the second color without the ink drying up in the first color, but the temperature of the printing paper increases during this ink drying period.

The overlapping pattern of the first color printing pattern and the second color printing pattern on the printing paper becomes the same as the printing pattern on the first color screen plate and the printing pattern on the second color screen plate. The overlay print pattern is shifted from the one shown in the image.

In addition, in screen printing, the pressurizing action of a squeegee against the screen plate causes the advancing screen plate to stretch during the printing process, and the original printing pattern on the screen plate without this stretching effect and the pattern printed while undergoing the stretching effect. The printed pattern on the printing paper is misaligned. Alternatively, the printing length of the printing paper vi placed along the circumferential surface is determined by the printing angle range defined by the predetermined rotation angle of the circumferential surface, so if the printing paper used becomes thicker, the printing length will increase. changes in the elongation direction, and as the printing paper becomes thinner, the printing length changes in the shortening direction. This variation results in a misalignment of the printing pattern between printing papers of different thicknesses.

(Problems to be Solved by the Invention) Therefore, in the present invention, a movable support body supporting the screen plate is provided with an inner support portion for supporting the screen plate and an inner support portion for supporting the screen plate, which are movable relative to each other in the reciprocating direction of the screen plate. A double structure consisting of an outer support part, which converts a displacement action in a direction intersecting the reciprocating direction of the screen plate into the reciprocating direction of the screen plate, and applies this converted displacement action to the inner support part. The body is supported by the outer support part, and a correction body is disposed on at least one side of the movable support body to apply a correction displacement action in the transverse direction to the converting body over a movement range of the converting body.

(Function) That is, as the movable support moves forward for printing, the converting body receives a correction displacement action from the correcting body according to its forward position. This corrective displacement effect is converted by the converter in the forward and backward movement direction of the movable support, and this converted corrective displacement effect is applied to the inner support section on which the screen plate is placed and supported. As a result, the inner support section is displaced forward or backward relative to the outer support section, and a longitudinal position correction is performed on the screen plate on the inner support section in accordance with the correction displacement effect received from the correction body. Therefore, by appropriately setting the correction displacement amount according to the expansion and contraction of the printing paper, deviations in the printing pattern caused by multicolor printing, screen plate expansion, changes in the thickness of the printing paper used, etc. can be accurately corrected. can do.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 4.

A moving support frame 4 is constructed and supported on a slide through a metal 3 between a pair of parallel guide rails 1 and 2.
a pair of left and right outer support parts 5 and 6 connected to the metal 3;
The inner support part 8 of the movable support frame 4 having a double structure is comprised of an inner support part 8 which is slidably supported back and forth via a loss roller bearing 7 between the support parts 5 and 6 on both sides. A screen plate 9 is fitted and supported in a replaceable manner.

Support pins 10 and 11 are properly attached to the front ends of the bisexual support parts 5 and 6, and receiving pieces 12 and 13 are fixed to both sides of the front end of the inner support part 8. Pressing springs 14, 14A are interposed between 11 and the receiving piece 12.13. As a result, the inner support part 8 becomes the outer support part 5.
．． 6 and is pressed backward.

A right-angled conversion lever 15.16 is supported on a support shaft 17.18 on the upper surface of the front end of the outer support portion 5.6 so as to be rotatable in a plane parallel to the plane containing the guide rails 1 and 2. Elongated holes 15a, 15a are formed at one end thereof, and rotors 15b, 16b are attached to the other end. The long holes 15a and 16a are the projections 3a of the inner support part 8.
, 3b, and from the support shaft 21.22 to the rotor 1.
5b and the correction bar 19.20 are set to the same distance from the support shaft 21.22 to the protrusions 8a, 8b. Therefore, the relative displacement between the outer support parts 5, 6 and the inner support part 8 based on the pressing action of the pressure spring 14 is caused by the engagement of the conversion lever 15. 16 rotational displacements, and this transformation becomes an equivalent transformation.

On the outside of the guide rails 1 and 2, correction bars 19 and 20 are attached to the support shaft 2 so as to be rotatable within the rotation plane of the conversion levers 15 and 16.
1.22, and a support frame 23.24 disposed outside the tips of both correction bars 19.20 has adjustment screws 25.26 in contact with the outer surfaces of the tips of the correction bars 19.20. It is screwed in such a way that it can be accessed. The correction bar 19.20 is
Rotors 15b, 16b of a conversion lever 15.16 that moves back and forth integrally with the moving support frame 4 along guide rails l, 2.
The pressure springs 14,
The rotor 15b is rotated by the pressing action of 14A.

16b is always in contact with the inner surface of the correction bar 19.20. When the movable support frame 4 is in its original position as shown in FIG. ing.

A cylinder 2.7 is disposed below the screen plate 9 so as to be able to reciprocate, and a pinion 28 (only one shown) attached to both ends of the cylinder 2.7 is connected to a rack 5a (one side (see figure). A driven gear 29 is arranged in parallel on the cylinder shaft 27a near one pinion 28, and the driven gear 29 has a sector gear 31 connected to a crank mechanism door 30 constituting a crank mechanism.
are engaged. As a result, the cylinder 27 rotates back and forth as the sector gear 31 moves back and forth, and the movable support frame 4 reciprocates back and forth in synchronization with the back and forth rotation of the cylinder 27.

Screen plate 9 and cylinder 2 that reciprocate in synchronization
7, the printing paper P is fed between the horizontal position setting pieces 32a, 32b on the paper feed plate 32 and the vertical position setting pieces 33a, 33b on the support 33, which rotates back and forth in synchronization with the reciprocating movement.
After the tip is fed and aligned with the positioning piece 34 on the cylinder 27, it is pressed and held by the presser claw 35 against the circumferential surface of the cylinder 27. The printing paper P is rotated by the cylinder 27 in this pressing and gripping state.
is drawn between the cylinder 27 and the screen plate 9,
The printing pattern on the screen plate 9 is transferred onto the printing paper P by the pressing action of the squeegee 36 on the screen plate 9 at a predetermined position.

Now, when performing multicolor printing, the thickness of the printing paper P and the amount of elongation of the screen plate 9 due to the pressure action of the squeegee 36 should be taken into account and adjusted before printing with the screen plate 9 for the first color. 25. Perform the screw position adjustment operation in 26,
Adjust the tilt angle 0 (in radians) of the correction bar 19.20 with respect to the guide rails 1 and 2.Movement support frame 4
If L is the distance when the converter lever 15 moves from the original position in FIG. 2 to the most advanced position in FIG. 3, that is, the printing length, then
The tilting amount of the correction bar 19.20 at the position corresponding to the most advanced position of the rotors 15b, 16b is Lθ, and the rotor 15
The conversion lever 15.16, which moves forward while contacting the correction bar 19.degree. If the tilting direction of the conversion lever 15.1 (i is inward (θ>0), the displacement action in the direction approximately perpendicular to the forward direction of the screen plate 9 is transferred by the conversion lever 15.16 to the forward direction of the screen plate 9. The inner support part 8 moves forward by a distance Lθ with respect to the outer support part 5°6 as shown by the solid line in FIG. ), the displacement action in the substantially orthogonal direction is converted to the receding direction of the screen plate 9 by an equal amount, and the inner support part 8 is moved to the outer support part 5, as shown by the chain line in FIG.
Disturbs the distance for 6 and moves backwards by 0 minutes. Correction bar 19.2
The forward correction or backward correction of the inner support part 8 due to the tilting of the squeegee 36 changes linearly according to the forward distance from the original position shown in FIG. The position correction is performed linearly from the front end side to the rear end side.

The following relationship exists between the printing length of the printing paper P and the thickness t of the printing paper P. If the radius of the cylinder 27 is Rc, the rotation angle of the cylinder 27 during the pressurizing action of the squeegee 36 is e (in radians), and the printing length of the printing paper P is Ll, then L1= (Rc+t)e in the screen plate 9. The printing length is as follows, assuming that the pinch circle radius of the pinion 2nd day is Rp.

L = Rp·○ If the elongation of the screen plate 9 and the printing paper P is 111 (viewing and assuming that L and Ll are equal, the following relationship is obtained.

Rc+t=Rp That is, for printing paper P with a predetermined thickness t, cylinder 2
The outer radius of the printing paper ■] wrapped around 7 and pinion 2
The pitch circle radius of 8 matches. The thickness of printing paper P is L
When the length changes from (L+Δt), the printing length L2 of the printing paper P becomes as follows.

L2-(Rc+t+At)e If you compare L and L2, there is a difference of Δmu・θ, and the amount of change Δ
The printing length of the printing paper P expands and contracts depending on the material.

Further, when the screen plate 9 is elongated by Δ per unit length due to the pressurizing action of the squeegee 36, if the movable support frame 4 is moved by a distance, the screen plate 9 is elongated by ΔL-L, and the printing length of the screen plate 9 is Searching becomes 1+ΔL)L.

If the thickness of the printing paper P is (t+Δt) and the amount of expansion/contraction per unit length of the screen plate 9 based on the pressure action of the squeegee 36 is ΔL, then the amount of expansion/contraction of the printing length of the printing paper P is Δt
- θ, the amount of expansion of the printing length of the screen plate 9 is ΔL−L. Therefore, in order to give the inner support portion 8 a correction displacement action corresponding to the sum of the expansion/contraction ■Δt・θ and the extension amount ΔL−L (Δt・e + ΔL・shi), the inclination angle θ of the correction bar 19.20 is Give the following values for .

θ=(Δt-e+ΔL-L)/L Then, if (Δt-0+ΔL-L)>O, tilt the correction bar 19.20 inward to obtain (Δt・(3+ΔI−・
L) < O tear h C correction C 19. 20 to the outside. As a result, the deviation between the printing length on the screen plate 9 side and the printing length on the printing paper P side is absorbed, and the original printing pattern on the screen plate 9 is accurately transferred onto the printing paper P.

Before printing with the screen plate for the second color, considering that the printing paper P will expand and contract due to the action of air temperature and humidity while the first color printing ink is drying after the first color printing is completed. Then, adjust the screwing position of adjustment screws 25 and 26. In this case, the amount of expansion/contraction per unit length is Δl
Then, the printing length of the printing paper P undergoes a new expansion/contraction of ΔN−L. Therefore, the total sum (ΔL・θ+ΔL・
In order to apply a correction displacement action of L+Δl・L) to the inner support portion 8, the following correction Δ is applied to the correction bar 19.20.
Give θ.

Δθ−ΔA −L/L=Δl This absorbs the printing pattern deviation caused by the expansion and contraction of the printing paper P when the ink dries between the first color printing and the second color printing, and the original printing on the screen plate 9 is The pattern is accurately transferred onto the printing paper P.

In addition, in this embodiment, the adjustment screws 25 and 26 are provided with correction scales 25.
a (only one side shown) is engraved so that the inclination angle θ of the correction bar 19° 20 can be set in accordance with the reference line 23a (only one side shown) engraved on the support frame 23, 24 side. It has become.

Therefore, it is possible to easily correct the misalignment of the printed pattern.

The present invention is, of course, not limited to the above-mentioned embodiment, but also includes the embodiments shown in FIGS. 5 and 6, for example.

In the embodiment shown in FIG.
7a and 38a, and the rotors 39a and 4Qa attached to one end side of the conversion lever 39.40 are connected to the groove 37a.
, 38a, and as in the previous embodiment, the left-right displacement action applied to the rotors 39a, 40a is converted to the back-and-forth movement direction of the screen plate 9 via the conversion lever 39°40, and the screen plate 9 9 undergoes longitudinal position correction relative to the outer support 5.6, and correction of the printing pattern is performed. Note that the length ratio between both arms of the conversion lever 39, 40 can be selected as appropriate, and the same applies to the conversion lever 15, 16 of the first embodiment.

In the embodiment shown in FIG. 6, an inner support part 42 constituting a movable support frame 41 is slidably fitted into a groove 43a of an outer support part 43, and is urged in the backward direction by a pressure spring 44. This pressing action causes the wedge-shaped block 4 to
Uke is stopped by 5.46. wedge-shaped block 45
．． 4G is attached to the inner ends of rods 47 and 48 supported by the outer support part 43 so as to be slidable in a direction perpendicular to the guide rails 1 and 2, and rotors 49 and 50 are attached to the other ends. . Rods 47, 4.8 are pressure springs 51
, 52 toward the correction bar 19.20, and the rotor 49.50 is constantly pressed against the inner surface of the correction bar 19.20. Inner support part 42 and wedge-shaped block 45
．． 46 refers to the operating inclined surfaces 42a, 42 on the inner support portion 42 side.
b and the action inclined surfaces 45a and 4 on the wedge-shaped blocks 45 and 46 side.
The correction bar 1 for the rotor 49.50 is connected via 6a and rolls on the inner surface of the correction bar 19.20.
The displacement action of 9.20 is converted into the longitudinal movement direction of the movable support frame 41 through the wedge-shaped blocks 45 and 46, and the same printing pattern correction as in each of the embodiments described above is performed.

Effects of the Invention As described in detail above, the present invention provides a converting body interposed between the inner support part for supporting the screen plate and the outer support part for supporting the inner support part, which are relatively movable in the reciprocating direction of the screen plate. At the same time, a correction body is disposed over the movement range of the conversion body to provide a displacement effect on the conversion body in a direction crossing the reciprocating direction of the screen plate, and the correction displacement effect in the cross direction is applied via the conversion body. Since it is applied to the inner support part, the displacement of the printing pattern caused by multicolor printing, pressure action of the squeegee, and changes in the thickness of the printing paper can be absorbed by the correction displacement action, and the printing pattern on the printing paper can be absorbed. This has an excellent effect in that accurate transfer of images can be performed.

[Brief explanation of the drawing]

1 to 4 show one embodiment embodying the present invention, and the first
The figure is a perspective view of the screen printing machine, the second figure is a plan view, and the third figure is a perspective view of the screen printing machine.
4 is a schematic side view, and FIG. 5.6 is a plan view showing another example of the present invention. a movable support frame 4 as a movable support, an outer support part 5.6,
Inner support part 8, screen plate 9, conversion lever 15.16 as a conversion body, correction bar 19.20 as a correction body,
A cylinder 27 as a circumferential body, a squeegee 36, a correction bar 37.38 as a first alternative correction body, a conversion lever 39.40 also as a conversion body, a movement as a second movement support A support frame 41, an inner support portion 42 and an outer support portion 43, wedge-shaped blocks 45 and 46 as converters, and printing paper P.

Claims (1)

[Scope of Claims] 1. Synchronizing the reciprocating back and forth movement of the screen plate and the reciprocating rotational movement of the circumferential body, and feeding printing paper between the screen plate and the circumferential body that perform the synchronized reciprocating movements, In a screen printing machine that presses the screen plate at a predetermined position with a squeegee to push out ink on the screen plate onto printing paper to perform printing, a movable support that supports the screen plate is moved in the direction of reciprocating movement of the screen plate. It has a double structure consisting of an inner supporting part for placing the screen plate and an outer supporting part for supporting the inner supporting part, which are relatively movable. A converter that converts the direction and applies the converted displacement action to the inner support part is supported by the outer support part, and the cross section is provided on at least one side of the movable support body over a movement range of the converter. 1. A printing pattern correction device for a screen printing machine, characterized in that a correction body is provided for applying a correction displacement action in a direction to the converting body. 2. The correction body is a correction bar disposed such that its tilt position can be adjusted with respect to the moving direction of the screen plate, and the conversion body is a bifurcated conversion lever whose one end side is in contact with the correction bar; 2. The printing pattern correction device for a screen printing press according to claim 1, wherein the correction displacement action of the correction bar on the lever is converted into the correction displacement action in the moving direction of the screen plate by rotation of the conversion lever. 3. The correction body is a correction bar disposed such that its inclination position can be adjusted with respect to the moving direction of the screen plate, and the converting body includes a rod whose one end side is in contact with the correction bar, and a rod supported at the other end side of the rod. The correction displacement action of the correction bar on this wedge-shaped block becomes the correction displacement action in the moving direction of the screen plate via the action inclined surface on the wedge-shaped block side and the action inclined surface on the inner support side. A printing pattern correction device in a screen printing machine according to claim 1, which is converted.