JPH0318832B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for driving a transfer pad in a pad printing press, and more particularly to a device for driving the pad according to an optimal speed change pattern in each movement path. .

(Prior art) A pad printing machine used for various types of printing involves installing a printing plate coated with ink and a substrate to be printed adjacent to each other, and first pressing a transfer pad made of silicone rubber or the like onto the printing plate. The printing pattern drawn on the surface is transferred to the pad, and the pad is then pressed against the printing material to print the printing pattern on the printing material, and the transfer pad is It moves vertically at the installation position of the printing plate and printing substrate, and horizontally between the installation positions of both, and repeats the above printing operation while reciprocating along a gate-shaped movement path as a whole. . Therefore, this type of pad printing machine is equipped with driving means for horizontal and vertical movement of the transfer pad, and conventionally, an air cylinder or a hydraulic cylinder is generally used as this driving means. Also, some large, high-speed pad printing machines use motors.

(Problems to be solved by the invention) By the way, in this type of pad printing machine,
It is necessary to set the horizontal movement distance of the transfer pad in the gate-shaped movement path in accordance with the distance between the installation positions of the printing plate and the printing medium. In addition, the optimum pressing force of the transfer pad against the printing plate and printing material varies depending on the shape of the printing pattern drawn on the printing plate, the material of the ink and transfer pad used, the surface shape of the printing material, etc. Since the installation heights of the pads also differ from one another, it is also necessary to set the vertical movement distances of the pads on the gate-shaped movement path at the positions where the printing plate and printing medium are installed. Therefore, in cases where a cylinder is used as a driving means for the transfer pad, adjustable mechanical stoppers are provided to regulate the upper and lower limit positions at both ends of the horizontal movement path and the vertical movement path. In those that drive the transfer pad, a cam mechanism is used to set the moving distance of each movement path of the pad.

However, in the case where the movement of the transfer pad by the cylinder is regulated by a mechanical stopper, when the movement of the cylinder or the transfer pad is stopped by the stopper, an impact is generated and the flexible transfer pad vibrates, especially the printing plate and the printing plate. If the pad vibrates when the transfer pad is pressed onto the printed matter, misalignment will occur in the transfer of the print pattern from the printing plate to the pad and in the printing of the print pattern from the pad to the substrate, resulting in printing defects. . To deal with this, it is possible to reduce the operating speed of the cylinder to reduce the impact or vibration of the transfer pad when it stops, but this increases the time required for one printing operation. As a result, efficiency will decrease.

On the other hand, in the case where the transfer pad is driven by a motor via a cam mechanism, by appropriately setting the cam profile, the overall movement time can be shortened, while the speed at the stop on each movement path can be reduced. Although it is possible to prevent the generation of shock and vibration of the transfer pad by slowing it down, the structure of this type of pad printing machine is extremely complicated due to the above-mentioned cam mechanism, and the shape of the printing pattern and the printing material When changing the travel distance of each gate-shaped travel path depending on the shape, size, etc. of There is a drawback that it is necessary to do so.

Therefore, the present invention makes it possible to freely and easily set the distance of each moving path of the transfer pad that moves in a gate-like manner between the printing plate and the printing material, and to adjust the moving speed of the pad in each moving path. can be controlled to an optimal change pattern that does not increase the travel time as a whole and does not cause impact when stopped. To enable efficient and good printing at all times regardless of the surface shape, size, etc. of an object.

(Means for Solving the Problems) That is, the present invention provides a pad printing machine in which a transfer pad is reciprocated along a gate-shaped movement path between a printing plate and a substrate. First and second AC servo motors, which rotate in response to input pulses, are used as driving means for horizontally moving the transfer pad between the printing plate installation position and the printing substrate installation position, and as a driving means for vertically moving the transfer pad in both of the above installation positions, respectively. and a movement mode setting means for setting the respective movement distances of the horizontal movement path in the gate-shaped movement path and the vertical movement path at the printing plate and printing substrate installation positions, and the movement distances are respectively set by the setting means. speed calculation means for calculating an optimum speed change pattern of the transfer pad in each of the travel paths determined, and the first and second AC servo motors configured to move the transfer pad according to the speed change pattern calculated by the calculation means. The present invention is characterized by comprising a pulse output means for outputting a pulse signal. If it is particularly necessary, the movement mode setting means sets the lowering time and upward movement time of the transfer pad at the printing plate installation position, and the lowering movement time and upward movement time of the transfer pad at the printing substrate installation position. The transfer pad is configured to be able to set the forward movement time and return movement time of the transfer pad between the two installation positions, respectively. It is configured to calculate an optimal speed change pattern according to the travel distance on the route and the travel time.

(Function) According to the above configuration, the movement mode setting means controls the gate shape of the transfer pad according to the shape of the printing pattern drawn on the printing plate, the material of the ink and transfer pad, the shape and size of the printing medium, etc. The moving distance of each of the horizontal and vertical paths in the moving path can be arbitrarily set, and the optimum speed pattern of the transfer pad is calculated by the speed calculating means for each moving path for which the moving distance is set. In this case, the calculating means may be configured to calculate speed changes for each movement path, such as starting the transfer pad at a low speed, gradually accelerating it, and then decelerating and stopping the pad when it reaches a sufficiently low speed. The pattern is calculated, and specifically, the output time interval of the number of pulses corresponding to the set moving distance is calculated so that the above-mentioned optimal speed change pattern is obtained. Then, the pulse signals whose output time intervals of each pulse are calculated in this way are outputted from the pulse output means to the first and second servo motors, respectively, so that the transfer pad can be moved for each set movement distance. The route will be moved according to the optimal speed change pattern as described above.

In addition, when the travel mode setting means can also set the travel time of each travel route, the speed calculation means sets the output time interval of the number of pulses corresponding to the travel distance for each travel route in the optimal manner as described above. Calculation is performed so that a speed change pattern is obtained and the total time is the set travel time.

(Example) Hereinafter, an example of the present invention shown in the drawings will be described.

First, the overall general configuration of the pad printing press according to the present embodiment will be explained with reference to FIG. Inverted L-shaped protrusion 2
The transfer pad 3, the ink plate 4, and the doctor blade 5 are suspended from the main body protruding portion 2b, and the base portion 2a
An ink tray 7 containing a printing plate 6 is installed on the top surface, and an extension stand 8 is provided in front of the stand 2a.
A printing material 9 is placed on top.

On the other hand, the transfer pad 3, the ink plate 4 and the doctor blade 5 are inside the main body protrusion 2b.
A driving device 10 is housed therein.

Next, to explain the structure of the drive device 10 with reference to FIGS. 2 and 3, a pair of side frames 11, 11 are provided on both left and right sides within the main body protruding portion 2b, and a pair of side frames 11, 11 are provided at the front end and the base end, respectively. A frame 12 and a rear frame 13 are erected. A pair of guide rods 14, 14 are installed on both left and right sides between the front frame 12 and the rear frame 13, and the first unit 20 has the transfer pad 3 attached to these guide rods 14, 14; An ink plate 4 and a second unit 30 to which a doctor blade 5 is attached are supported. These units 20 and 30 each have a slide base 2.
1 and 31, and cylinder bodies 22, 22 and 32, 32 fixed to both ends of the bases 21, 31, respectively, are fitted into the guide rods 14, 14 and supported so as to be movable back and forth. And the first unit 2
0 and the upper surface of the slide base 31 of the second unit 30 are fixedly provided with sleeves 23 and 33 having female threads formed on their inner peripheral surfaces, respectively, and the front and rear frames 12,
First and second horizontal drive shafts 41 and 42 having male threads are installed between the shafts 41 and 42.
and the sleeves 23 and 33 are screwed together, respectively. Further, a first AC servo motor 43 is provided on the rear surface of the rear frame 13, and the rotating shaft of the motor 43 is directly connected to the first horizontal drive shaft 41, and the first and second horizontal drive shafts 41, 42 A belt 44 is wound between them. As a result, both drive shafts 41 and 42 are simultaneously rotated by the motor 43, and accordingly, the first and second units 2
The transfer pad 3, ink plate 4 and doctor blade 5 attached to these units 20, 30 are horizontally moved back and forth along guide rods 14, 14.
Here, the diameters of the pulleys 45 and 46 around which the belt 44 is wound are set so that the rotation speed of the first horizontal drive shaft 41 is faster than the rotation speed of the second horizontal drive shaft 42, and The first unit 20 is configured to move more than the second unit 30 for a constant rotation amount of the servo motor 43, and at the backward end, the slide bases 21, 31 of both units 20, 30 move up and down. Although they are in an overlapping state, at the forward end, as shown in FIGS. 1 and 2, the first unit 20 is located near the front end of the main body protrusion 2b, while the second unit 30 is located in the middle of the protrusion 2b. That is, the first unit 2
The transfer pad 3 attached to the second unit 30 moves horizontally between the printing plate 6 and the printing substrate 9 shown in FIG. It's starting to move back and forth.

On the other hand, on the slide base 21 of the first unit 20, a vertical drive shaft 51 with a male screw is rotatably provided, and the shaft 51 and
A belt 53 is wound around the rotating shaft of a second AC servo motor 52 installed on the slide base 21 . Further, guide sleeves 5 are provided on both sides of the vertical drive shaft 51 in the slide base 21.
4 and 54 are fixed in the vertical direction, and a guide rod 5 is installed inside these sleeves 54 and 54.
5 and 55 are fitted so as to be vertically movable. The upper and lower ends of both guide rods 55 and 55 are connected by connecting members 56 and 57, respectively, and a sleeve 58 having a female thread formed on the inner peripheral surface is fixed to the upper connecting member 56. is screwed onto the vertical drive shaft 51, and is connected to the lower connecting member 57.
As shown in FIG. 1, the transfer pad 3 is attached to the transfer pad 3 via a support shaft 58 and a pad attachment member 59.
2 causes the transfer pad 3 to move between the guide rods 55, 55 and the connecting member 56,
57, it can be moved up and down.

The ink plate 4 and doctor blade 5 are connected to the second unit 30 as shown in FIG.
It is supported on the lower surface of the slide plate 31 via an elevating mechanism 34, and is moved up and down at a predetermined timing by the elevating mechanism 34 as the slide base 31 moves back and forth. In other words,
When the ink plate 4 moves forward, it is in a downward position and applies the ink in the ink tray 7 to the upper surface of the printing plate 6.
Further, the doctor blade 5 is positioned downward when retracting to scrape off excess ink on the upper surface of the printing plate 6.

In addition to the above configuration, this pad printing press 1 is equipped with a control unit 60 that controls the operation of the first and second AC servo motors 43 and 52. This control unit 60 is
As shown in FIG.
a memory unit 62 that transfers data between the
An input interface 63 inputs signals from sensors and switches for detecting the position of the transfer pad 3 to a calculation section 61, and an input interface 63 that inputs signals from the calculation section 61 to a solenoid for driving the ink plate 4 and doctor blade 5. An output interface 64 that outputs an output to a relay for emergency stop brake, etc., first and second pulse generators 65 and 66 that generate pulse signals according to the calculation result of the calculation unit 61, and first and second servos. first and second control signal input/output sections 67 that input and output control signals for the motors 43 and 52;
68. Then, the pulse signal from the first pulse generating section 65 and the first control signal input/output section 6
7 is input to the first AC servo motor 43 via the D/A converter 69 and amplifier 70, and a signal from the encoder 71 provided in the motor 43 is input to the D/A converter 69.
The signal is fed back to the first control signal input/output section 67 via the control signal input/output section 67. Similarly, the pulse signal from the second pulse generator 66 and the control signal from the second control signal input/output section 68 are transmitted to the D/A converter 7.
2. A signal is input to the second AC servo motor 52 via the amplifier 73, and a signal from the encoder 74 provided in the motor 52 is input to the second control signal input/output section 68 via the D/A converter 72. It's starting to get feedback.

Further, a keyboard 75 as an external input device for data setting and a display 76 as a display device for various data are connected to the arithmetic unit 61, and signals are input and output between these. ing. The keyboard 75 has a fifth
As shown in the figure, a home position A on the gate-shaped path where the transfer pad 3 is to be moved from the origin 0 set at a predetermined position of the main body 2 of the pad printing machine 1.
(the point above the printing substrate 9 where the moving direction changes from horizontal to vertical or vice versa), the horizontal distance l ₁ and the vertical distance l ₂ from the home position A to the point above the printing plate 6. The horizontal distance L ₁ to position B,
Pressing position C from the position B to the printing plate 6 below
vertical distance L ₂ to the home position A above
Vertical distance L ₃ from the position D to the pressing position D on the printing substrate 9 below, the backward movement (backward) time T ₁ and the forward movement of the transfer pad 3 between the home position A and the position B above the printing plate. Movement (advance) time T ₂ , downward movement time T ₃ and upward movement time T ₄ of the transfer pad 3 between the printing plate upper position B and the printing plate pressing position C, the above home position A and the printing substrate The downward movement time _T5 and the upward movement time _T6 of the transfer pad 3 between the pressing position D and the pressing position D can be set. still,
The horizontal distance L ₁ from the home position A to the upper position B of the printing plate may be set by the horizontal distance l ₁ ' from the second origin 0' set on the main body 2, or each of the above data. In addition, it may be possible to set the round trip time T of the gate-shaped moving route from the home position A through each position B→C→B→A→D and back to the home position A.

Next, the operation of the above embodiment will be explained with reference to the flowchart of FIG. 6 showing the operation of the control unit 60.

First, when the power switch is turned on, the control unit 60 operates the first and second AC servo motors 43 and 52 to move the transfer pad 3 in step _S1 .
to the origin 0 shown in Figure 5, and then step
In _S2 , an optimal speed change pattern for the transfer pad 3 is created. In that case, in the pattern creation immediately after startup, each of the above data L ₁ to _{L 3} and T ₁ to
The T ₆ (and T) that was set during the previous work is used, but specifically, each route that makes up the portal movement route, namely A → B, B → C, C → B, B → A,
For each of the six routes A→D and D→A, an optimal speed change pattern for the transfer pad 3 is created based on the set travel distances L ₁ to L ₃ and travel times T ₁ to _{T 6} . Transfer pad 3 according to the pattern
The number of pulses of the pulse signal for moving the pulse signal and its output time interval are calculated. Further, as the optimum speed change pattern, as shown in FIG. 7, a pattern is set in which the robot starts moving at a low speed, gradually accelerates, then decelerates, and stops when the speed reaches a sufficiently low speed.

Next, the control unit 60
At _S3 , pulse signals are output to the first and second AC servo motors 43 and 52 to move the transfer pad 3 horizontally and vertically by distances _l1 and _l2, respectively, and the transfer pad 3 is returned to the home position. At the same time, it is determined in step _S4 whether or not the data setting has been changed using the keyboard 75. If no change has been made, the data is set to A, and if it has been changed, a new one is set in accordance with steps _S5 and _S6 . After storing the data set and checking the data for errors, step _S7 is executed to determine whether the start switch has been turned on. Then, when the start switch is turned on, the control unit 60 executes step _S8 , and if the data has not changed, immediately executes it, and if the data has changed, executes step _S2 described above to change the data. After recalculating the number of pulse signals and their output time intervals to obtain the optimal speed change pattern as shown in Fig. 7 based on the data obtained, in step _S9 , the pulse signals are applied to the first and second AC servos. Output to motors 43 and 52. As a result, the transfer pad 3 is first moved from the home position _A to the position B by the first AC servo motor 43 in a speed change pattern as shown in _FIG. It is stopped when the number of pulses corresponding to .

Through this operation, the transfer pad 3
is pressed against the printing plate 6 coated with ink by the ink plate 4 and doctor blade 5, and the printing pattern drawn on the printing plate 6 is transferred to the surface thereof, and the printing pattern is transferred along the gate-shaped movement path. The printing pattern is printed on the printing material 9 by moving the transfer pad 3 and then pressing it against the printing material 9. In this case, the transfer pad 3 moves along each path constituting the gate-shaped movement path. Since the pad 3 moves according to the optimum speed change pattern as shown in FIG. 7, shocks and vibrations when the pad 3 is stopped can be prevented or reduced without unnecessarily lengthening the travel time. Therefore, when the transfer pad 3 is pressed against the printing plate 6 and the printing material 9, displacement of printing due to vibration of the pad 3 is prevented, and a good printing condition can always be obtained.

(Effects of the Invention) As described above, according to the present invention, the printing pattern drawn on the printing plate is printed on the printing material by moving the transfer pad in a gate-like manner between the printing plate and the printing material. In the pad printing machine, the distance of each path constituting the gate-shaped movement path of the transfer pad can be freely set, and the shape of the printing pattern, the material of the ink and transfer pad, or the size of the printing substrate can be freely set. The optimum movement path can be easily set according to the pod surface shape, etc., and the transfer pad is moved along each path according to the optimum speed change pattern according to the set distance (and movement time). This will prevent the generation of shocks and vibrations when the pad is stopped. As a result, printing work efficiency and finishing accuracy can be improved without using a complicated or large-scale mechanism.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic side view of the entire pad printing machine, FIG. 2 is an enlarged plan view of the pad driving device, and FIG. 4 is a block diagram showing the configuration of the control unit, FIG. 5 is an explanatory diagram of the travel distance and travel time of the pad movement route set by the keyboard, and FIG. 6 is a flowchart showing the operation of the control unit. The chart diagram, FIG. 7, is a graph showing an example of a speed change pattern. 3... Transfer pad, 6... Printing plate, 9... Printing material, 10... Drive device, 43, 52... First, first
2AC servo motor, 60...control unit (speed calculation means, pulse output means), 75...
Keyboard (movement mode setting means).

Claims (1)

[Claims] 1. By reciprocating a transfer pad along a gate-shaped path between a printing plate coated with ink and a substrate, a printing pattern drawn on the printing plate is transferred to the pad. A driving device for the transfer pad in a pad printing machine configured to print on a printing material after transfer, comprising: a first AC servo motor for horizontally moving the transfer pad between a printing plate installation position and a printing substrate installation position; , a second AC servo motor that moves the pad vertically at both installation positions, and a horizontal movement distance of the transfer pad by the first AC servo motor and a first
a movement mode setting means for setting each vertical movement distance at the printing plate installation position and printing substrate installation position by the 2AC servo motor; a speed calculation means for calculating an optimum speed change pattern; and a pulse output means for outputting a pulse signal to the first and second AC servo motors so as to move the transfer pad according to the speed change pattern calculated by the calculation means. A transfer pad drive device for a pad printing machine, characterized in that it has: 2. The movement mode setting means determines the downward movement time and upward movement time of the transfer pad at the printing plate installation position, and the forward movement time and backward movement time of the transfer pad between the printing plate installation position and the printing substrate installation position. , is configured to be able to set the downward movement time and upward movement time of the transfer pad at the printing substrate installation position, and the speed calculation means is configured to be able to set the moving distance for each movement set by the movement mode setting means. Claim 1 is characterized in that the transfer pad is configured to calculate an optimum speed change pattern for the transfer pad so that the transfer pad moves along each of the above-mentioned travel times along the respective paths set by the movement mode setting means. Transfer pad drive device for pad printing machines. 3. The speed calculation means is configured to calculate an optimal speed change pattern so that the transfer pad starts moving at a low speed, gradually accelerates, decelerates again, and stops when the speed reaches a sufficiently low speed in each movement path. Claim 1 characterized in that
A transfer pad drive device in a pad printing machine according to item 1 or 2.