JPH11123810A - Pad printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to print an image with a thick coat without deteriorating a printing efficiency, in a pad printing machine which transfers an ink for forming a specified pattern to a matter to be printed by first, causing the ink for forming a specified pattern to stick to a transfer pad by pressing the transfer pad to a printing plate to which the ink is applied. SOLUTION: After pressing a transfer pad 10 to a heater 60 and thereby heating the transfer pad 10 before the movement of a printing plate 37 to a transfer position, the transfer pad 10 is pressed to the printing plate 37 to which an ink is applied and thereby, the ink for forming a print pattern is transferred to the transfer pad 10. Thus the ink is satisfactorily transferred to a matter to be printed X, even when the coating build-up of the ink is increased, by promoting the volatirization of a solvent component contained in the ink, as a structural feature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of printing, and more particularly to the field of pad printing machines using transfer pads.

[0002]

2. Description of the Related Art A pad printing machine used for printing various articles such as resin molded articles is provided with a printing plate to which ink is applied and a printing material placed adjacent to each other.
By reciprocating the transfer pad along the gate-shaped path between the printing plate and the printing material, first, the transfer pad is pressed against the printing plate coated with ink, and the predetermined printing surface provided on the printing plate is pressed. After the ink in the grooves constituting the printing pattern is applied, the transfer pad is pressed against the substrate to transfer the ink constituting the pattern to the substrate. Printing machines include an ink tray type and an ink container type.

In the ink container type, an ink container having a lower surface opened is placed on a printing plate, and the ink stored in the ink container is provided on the printing plate by moving the printing plate. The ink is not applied to the outside air because the ink is applied to the printed pattern forming grooves, and the evaporation of the volatile solvent contained in the ink is suppressed, thereby preventing the workplace environment from being deteriorated. At the same time, there is an advantage that the viscosity of the ink is kept constant and a good finish is maintained.

[0004]

By the way, according to the pad printing machine, the transfer pad can be moved between the printing plate and the printing material at high speed by either the ink tray type or the ink container type. In this case, high printing efficiency is obtained, but in this case, the ink is transferred from the printing plate to the transfer pad within a very short time after the ink is attached to the transfer pad. Is transferred to the printing material in a state where the solvent component contained in the ink is not sufficiently volatilized, and the following problem occurs.

[0005] That is, if the solvent component in the ink is not sufficiently volatilized, the viscosity of the ink becomes small and the required adhesive strength to the printing material cannot be obtained. The remaining ink causes a lack of a pattern, a lack of print density, or the like, and a low-viscosity ink is pressed against a printing material, so that the lines constituting the print pattern are blurred or thickened.

[0006] In particular, the problem due to insufficient volatilization of the solvent component is that, in order to perform printing with a large film thickness, the printing pattern forming groove provided on the printing plate is made deep to adhere to the transfer pad. This becomes remarkable when the amount of ink is increased.

[0007] Therefore, in a pad printing machine, the amount of ink adhered from a printing plate to a transfer pad must be reduced so that the solvent component in the ink is transferred to a printing material in a sufficiently volatilized state. Printing with a large film thickness such as screen printing has been considered difficult.

Further, when printing with a large film thickness by increasing the amount of ink to be attached to the transfer pad, it is necessary to lengthen the time from pressing the pad to the printing plate to pressing the pad against the printing material. It is conceivable to transfer after sufficiently evaporating the solvent component therein, but in this case, the printing efficiency is remarkably reduced.

Accordingly, the present invention provides an ink container-type pad printing machine as described above without lowering printing efficiency.
Moreover, it is an object to provide a pad printing machine capable of performing printing with a large film thickness.

[0010]

In order to solve the above problems, the present invention uses the following means.

First, the invention according to claim 1 of the present application (hereinafter referred to as the invention)
An ink container having a lower end opened, a printing plate in which ink is applied to a print pattern forming groove by moving relatively in contact with the lower end of the ink container,
A printing plate driving means for applying ink to the pattern forming grooves by horizontally moving the printing plate in the longitudinal direction thereof, and a transfer pad for transferring the ink forming the printing pattern from the printing plate and transferring the ink to a printing substrate, In a pad printing machine provided with pad driving means for raising and lowering the transfer pad and pressing the transfer pad against a printing plate and a printing material, a heater for heating the transfer pad is arranged on a side of a position above the transfer pad. At the same time, the transfer pad is swingable from a downward position to a lateral position facing the side where the heater is disposed.
A pad rocking means for rocking the transfer pad between a downward position and a horizontal position; and a heater for horizontally moving the heater and pressing the transfer pad against the transfer pad rocked in the horizontal position at the upper position. And a driving means.

According to a second aspect of the present invention (hereinafter referred to as a second aspect), in the first aspect, a reaction force generated when the transfer pad is pressed against the printing plate and the printing substrate causes the transfer pad to move in a predetermined direction. The rotational center of the transfer pad is offset from the center line of the transfer pad so that the rotational force of the transfer pad is generated, and the transfer by the rotational force is performed when the transfer pad is pressed against the printing plate and the printing material. It is characterized in that a stopper for restricting swinging of the pad and holding the pad in a downward position is provided.

Further, the invention according to claim 3 (hereinafter referred to as third invention)
The invention is characterized in that the stopper according to the second invention is configured using a shock absorber that absorbs an impact when the transfer pad swings from a horizontal position to a downward position and comes into contact with the stopper.

The invention according to claim 4 (hereinafter referred to as the fourth invention)
The invention is characterized in that in any one of the first to third inventions described above, after the transfer pad is swung in the horizontal position at the upper position, the heater is pressed against the transfer pad, and then the transfer pad is placed in the downward position. Pad driving means, so as to be pressed vertically against the printing plate and the printing material in order
A control means for controlling the operation of the pad swinging means, the heater driving means and the printing plate driving means is provided.

By using such means, the following effects can be obtained according to each of the above inventions.

According to the first aspect of the invention, the heater is horizontally moved by the heater driving means in a state where the transfer pad is in the horizontal position at the upper position before the ink of the print pattern forming groove is attached to the transfer pad. This makes it possible to press the heater against the transfer pad. Therefore, as described above, the transfer pad is first pressed against the heater and heated, and then the transfer pad is placed in a downward position, and the transfer pad is pressed against the printing plate coated with ink in the printing pattern forming groove to form the pattern. If ink is adhered, and then the transfer pad is pressed against the printing material, the ink constituting the pattern is transferred from the transfer pad to the printing material.
Since the transfer pad is heated by the heater before the ink is applied from the printing plate as described above, the ink applied to the transfer pad is subsequently heated by the heat of the transfer pad. Thus, the evaporation of the solvent component contained in the ink is promoted.

Therefore, even if the printing pattern forming groove provided on the printing plate is made deep and a large amount of ink adheres to the transfer pad from the printing plate, the solvent component in the ink is transferred to the printing material. By this time, sufficient volatilization is achieved to obtain the required viscosity or adhesive strength. As a result, printing with a large amount of ink, that is, printing with a large film thickness can be performed favorably without increasing the time from the attachment of the ink from the printing plate to the transfer pad to the transfer to the print substrate.

According to the first aspect of the present invention, the heater is provided on the side of the upper position of the transfer pad.
The ink in the ink container or on the printing plate is less likely to be affected by the heat of the heater, and the ink can be prevented from being solidified by the heat.

By the way, if the transfer pad can be swung from the downward position to the horizontal position as described above, when the transfer pad is pressed against the printing plate or the printing material in the downward position, the reaction force is applied in either direction by the reaction force. Rotational force may be generated to cause rocking. At this time, the adhesion of ink from the printing plate to the transfer pad and the transfer of ink from the transfer pad to the printing material are not performed well.

Therefore, in the second invention, even if a rotational force is generated in the transfer pad when the transfer pad is pressed against the printing plate and the printing substrate, the rotational force is always generated in a predetermined direction, and The rotation of the transfer pad due to its rotational force is regulated by the stopper, which makes it possible to reliably hold the transfer pad in a downward position when pressing the transfer pad against the printing plate and the printing medium. Adhesion of the ink from the printing plate to the transfer pad and transfer of the ink from the transfer pad to the printing substrate are performed favorably.

Further, according to the third aspect of the invention, the stopper in the second aspect of the invention is constituted by using a shock absorber, so that the vibration when the transfer pad swings from the horizontal position to the downward position can be quickly absorbed. Can be
Immediately after the transfer pad is heated by the heater, the transfer pad can be pressed against the printing plate.

According to the fourth aspect of the invention, the operation of the first aspect of the invention is automatically achieved by the control means, so that printing with a large film thickness can be performed more efficiently and easily. become able to.

[0023]

Embodiments of the present invention will be described below.

First, the overall structure of the pad printing machine 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. The pad printing machine 1 includes a machine base 2 and a vertical And a main frame 3 having an inverted L-shape in side view, which is provided and whose upper part projects forward.

A guide rod 4 extending in the front-rear direction (left-right direction when viewed from the side) is provided in a forwardly projecting portion of the main body frame 3, and a slide member 5 is slidably supported by the guide rod 4. A screw shaft 6 is installed in parallel with the guide rod 4. The slide member 5 is screwed to the screw shaft 6, and a motor 7 for rotating the screw shaft 6 is provided. When the screw shaft 6 is driven to rotate by the motor 7, the slide member 5 moves back and forth. A cylinder 8 is mounted on the slide member 5 and a cylinder rod 8 a extending downward from the cylinder 8.
A transfer mechanism 9 is attached to a lower end of the transfer mechanism 9, and the entire transfer mechanism 9 is moved up and down by operation of the cylinder 8.

The driving of the slide member 5 in the front-rear direction can be performed by a cylinder or the like instead of the motor 7. In this case, the movement of the slide member 5 in the front-rear direction by the cylinder is regulated at a predetermined position by a stopper member using, for example, a shock absorber.

Here, the structure of the transfer mechanism 9 will be described. This mechanism 9 includes a transfer pad 10 and a swing mechanism 11 for swinging the transfer pad 10 from a downward posture to a rearward lateral posture.

As shown in FIGS. 3 and 4, the swing mechanism 11 has a horizontal lifting plate 12 attached to the lower end of a cylinder rod 8a projecting downward from the inside of the main body frame 3. The lift plate 12 is moved up and down along the two guide rods 13 by the cylinder 8 described above.

On the lower surface of the elevating plate 12, two mounting plates 14, 14 'are mounted vertically and parallel to each other, and a downward opening is provided between the mounting plates 14, 14'. A U-shaped pad mounting member 15 is disposed, and rotating shafts 16 and 16 ′ provided on both sides thereof are attached to mounting plates 14 and 1.
4 'is mounted in a straight line via bearings 17, 17'.

The transfer pad 10 is suspended from the pad mounting member 15 via an XY adjustment mechanism 18, and is free to swing around the axes of the rotating shafts 16 and 16 '. .

On the other hand, a rotary cylinder mounting plate 19 is mounted on the side of the elevating plate 12 so as to be parallel to the mounting plates 14, 14 ', and a rotary cylinder 20 is mounted on the mounting plate 19. .

A drive shaft 21 of the rotary cylinder 20 is connected to the pad mounting member 15 via a connecting member 22, whereby the transfer pad 10 swings by the operation of the rotary cylinder 20. I have.

The center of the rotation shafts 16 and 16 'with respect to the mounting plates 14 and 14' is offset rearward from the center line of the support shaft 10 'of the transfer pad 10 by a distance d, and the rotation shafts 16 and 16' In order to prevent the transfer pad 10 from tilting from the downward position to the forward sideways position around the center point of 16, 16 ', a stopper 23 is provided.
The pad mounting member 15 is mounted via a stopper mounting member 24 so as to abut on the left rear surface in front view.

On the other hand, as shown in FIGS. 2 and 5, a rail member 31 extending forward through a mounting base 30 is provided at the center of the upper surface of the machine base 2 and provided below the slide base 32. The engagement member 33 is engaged with the rail member 31,
The slide table 32 is supported on the rail member 31 so as to be movable in the front-rear direction. A cylinder 34 is installed on the upper surface of the machine base 2 in parallel with the rail member 31.
Since the piston rod 34a of the cylinder 34 is attached to the bracket 32a provided at the distal end of the slide table 32, the slide table 32 is moved in the front-rear direction by the operation of the cylinder 34.

A stopper member 35 using a shock absorber is provided upright at the front end of the upper surface of the machine base 2, and a bracket 32b is provided at the front end of the slide base 32.
The advancing of the slide table 32 is restricted at a position where the contact member 36 attached via the contact member comes into contact with the stopper member 35.

As shown in FIG. 2, a printing plate 37 provided with a print pattern forming portion 37a on the front side is set on the slide table 32 as shown in FIGS. In addition, an ink container 38 having an open lower surface is placed on the upper surface of the printing plate 37.

A front end of a pair of arms 40, 40 extending forward with a rear end pivotally connected to the frame body 3 is connected to a pressure ring 39 mounted on the ink container 38. At the same time, springs 43, 43 are mounted between spring receivers 41, 41 provided on the frame main body 3 and spring mounts 42, 42 provided on the arms 40, 40, and the urging force of the springs 43, 43 is provided. Arm 40,
By pressing down 40, the ink container 38 is pressed against the printing plate 37 with an appropriate force via the pressure ring 39.

The printing plate 37 is moved by the cylinder 34 from the rearward position where the printing pattern forming portion 37a is located below the ink container 38 to the printing pattern forming portion 37a.
Is moved to the front position where it protrudes forward, so that the ink in the ink container 38 is applied to the print pattern forming portion 37a.

As shown in FIGS. 1 and 2, an extension base 50 is provided at the front of the machine base 2 so as to protrude forward.
A work (substrate to be printed) X is placed on the extension table 50 via a receiving table 51.

The receiving table 51 is composed of upper and lower members 51a and 51b which are relatively movable in the left-right direction when viewed from the front in FIG. The position of the workpiece X on the receiving table 51 can be adjusted in the front, rear, left, and right directions.

Then, the entire transfer mechanism 9 including the transfer pad 10 is moved by the operation of the motor 7 so that the transfer position where the printing pattern forming portion 37a of the printing plate 37 located at the front position is located and the printing object X is set. The transfer pad 10 moves up and down at these two positions by the operation of the cylinder 8 while moving horizontally between the printing positions.

In addition to the above, the pad printing machine 1 is provided with a heater 60 for heating the transfer pad 10.

That is, as shown in FIG.
A cylinder 61 is attached to the main body frame 3 on the side of the upper position at the transfer position of 0, and a heater 60 is attached to the tip of a cylinder rod 61a extending forward of the cylinder 61 with the heating surface facing forward. The heater 60 moves forward or backward by the operation of the cylinder 61.

In this case, the cylinder 61 is supported by the frame main body 3 via the rail members 62 engaged with each other. Can be adjusted.

Next, the operation of the pad printing machine will be described.

First, it is assumed that the previous transfer operation to the printing medium is completed, and the transfer pad 10 is located above the transfer position as shown in FIG. In this state, as shown in FIG. 7, after the transfer pad 10 is swung from the downward posture to the rearward lateral posture by the rotary cylinder 16, the heater 60 is moved forward by the cylinder 61. Thus, the heater 60 is pressed against the transfer pad 10, and the transfer pad 10 is heated by the heater 60.

Next, as shown in FIG. 8, the heater 60 is moved backward by the cylinder 61, and the transfer pad 10 is swung from the horizontal position to the downward position by the rotary cylinder 20, and thereafter, the transfer pad 10 is moved by the cylinder 8. Lower it. At this time, the printing pattern forming portion 37a of the printing plate 37 sliding directly below the transfer pad 10
Is transferred to the transfer pad 10.

When the above transfer operation is completed, the printing plate 37 is retracted rearward in preparation for the next transfer.

As shown in FIG. 9, the transfer pad 10 is once raised by the cylinder 8, and the transfer pad 10 is horizontally moved by the motor 7 to a position immediately above the printing object X.
The transfer pad 10 is lowered again by the cylinder 8 and pressed against the printing substrate X. As a result, the ink is transferred from the transfer pad 10 to the printing material X, and a predetermined pattern is printed on the printing material X.

Incidentally, in FIG. 10, the transfer pad 1
The following effects can be obtained by offsetting the swing center of 0 and providing the stopper 23.

That is, when the transfer pad 10 is pressed against the printing plate 37 or the printing material X, the transfer pad 10 receives an upward reaction force from them.
If 0 is allowed to swing from the downward posture to the lateral posture, there is a possibility that the reaction force a may generate a rotational force in any direction and tilt. At this time, there are disadvantages that the ink of the pattern forming portion 37a does not accurately adhere to the transfer pad 10 or that the printing on the printing substrate is shifted.

Therefore, in this embodiment, the transfer pad 1
The center of swing of 0 is offset from the center line of the transfer pad 10 so that a rotational force (arrow A) always acts on the transfer pad 10 in a predetermined direction. By contacting the contact surface 25 on the rear surface 15 'on the left side of the view, the rotational force is canceled, the tilt of the transfer pad 10 is prevented, and the downward posture is maintained. Thereby, the adhesion of the ink from the printing plate 37 to the transfer pad 10 and the transfer of the ink from the transfer pad 10 to the printing substrate X are accurately performed.

When the transfer pad 10 swings at high speed from the horizontal position to the downward position after the heater 60 is pressed against the transfer pad 10 and retreats, the transfer pad 10 is not immediately stopped but vibrates. Printing plate 37 as it is
, The ink of the pattern forming portion 37a does not accurately adhere to the transfer pad 10, and the accuracy of ink adhesion is reduced.

Therefore, the above-mentioned vibration is absorbed by the stopper 23 formed by using a shock absorber, and the ink of the pattern forming portion 37a is accurately adhered to the transfer pad 10.

Further, by mounting the heater 60 at the above-described position, the heat of the heater 60 is less likely to be transmitted to the ink inside the ink container 38 and the ink on the printing plate 37, and the heat causes the heat inside the ink container 38 and the printing plate 37 As a result, it is possible to prevent the solvent component of the ink from volatilizing and to solidify the ink, and to allow a space for cleaning the pad.

[0056]

As described above, according to the pad printing machine of the present invention, the transfer pad is heated by the heating means before pressing the transfer pad against the printing plate, so that the transfer pad can be pressed against the printing plate. The ink attached to the transfer pad is heated by the pad, and the solvent component contained in the ink is quickly volatilized.

Therefore, even if the pattern forming groove provided in the printing plate is deepened so that a large amount of ink adheres to the transfer pad from the printing plate, the solvent component in the ink is transferred to the printing material. Sufficiently volatilized to obtain a required viscosity or a required adhesive strength to a substrate.

Accordingly, printing with a large amount of ink can be performed well without causing bleeding or the like, without increasing the time from the attachment of the ink on the transfer plate to the transfer pad and the transfer to the printing material. Thus, as this kind of pad printing machine, a pad printing machine having good printing efficiency and excellently performing thick film printing is realized.

Further, by providing the heater at the above position, the ink in the ink container and on the printing plate is less affected by the heat of the heater, and the ink is solidified in the ink container and on the printing plate. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view of a pad printing machine according to an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of the pad printing machine.

FIG. 3 is an enlarged front view of a transfer mechanism of the pad printing machine.

FIG. 4 is an enlarged side view of a transfer mechanism of the pad printing machine.

FIG. 5 is an enlarged view taken along an arrow line in FIG. 2;

FIG. 6 is a plan view showing a stamp plate and a pattern forming section of the pad printing machine.

FIG. 7 is a partially broken side view showing another operation state.

FIG. 8 is a partially broken side view showing another operation state.

FIG. 9 is a partially cutaway side view showing another operation state.

FIG. 10 is an action diagram of a force acting on a transfer pad of the pad printing machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pad printing machine 8 pad driving means 10 transfer pad 23 stopper 34 printing plate driving means (printing plate driving device) 37 printing plate 60 heater 61 heater driving means (heating device driving device) X substrate (work)

Claims (4)

[Claims] An ink container having a lower end opened, a printing plate in which ink is applied to a printing pattern forming groove by being relatively moved in contact with the lower end of the ink container, and a printing plate in a longitudinal direction thereof. A printing plate driving means for applying ink to the pattern forming grooves by moving the printing plate horizontally, a transfer pad for copying the ink forming the printing pattern from the printing plate and transferring the ink to a printing material, What is claimed is: 1. A pad printing machine comprising: a pad driving means for pressing a printing plate and a printing material; wherein a heater for heating the transfer pad is disposed on a side of a position above the transfer pad; The pad is swingable from a downward position to a horizontal position facing the side where the heater is disposed, and the pad is configured to rock the transfer pad between the downward position and the horizontal position. A pad printing machine comprising: a pad swing unit; and a heater driving unit that horizontally moves the heater and presses the transfer pad that has been swung in a horizontal position at an upper position. 2. The center of oscillation of the transfer pad is such that a rotational force in a predetermined direction is generated on the transfer pad by a reaction force when the transfer pad is pressed against the printing plate and the printing medium. And a stopper for restricting the transfer pad from swinging due to the rotational force when the transfer pad is pressed against the printing plate and the printing material, and holding the transfer pad in a downward position. The pad printing machine according to claim 1, wherein 3. The stopper according to claim 2, wherein the stopper is configured by using a shock absorber that absorbs a shock when the transfer pad swings from a horizontal position to a downward position and contacts the transfer pad. Pad printing machine. 4. After the transfer pad is swung in a horizontal position at an upper position, a heater is pressed against the transfer pad, and then the transfer pad is moved up and down in a state where the transfer pad is in a downward position, so that the printing plate and the printing material are moved. 4. A control means for controlling the operation of a pad driving means, a pad swinging means, a heater driving means and a printing plate driving means so as to sequentially press the pad driving means. A pad printing machine as described in Crab.