JPH0514854Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inking device in printing machines such as multicolor offset printing machines and rotary presses, and particularly to a device effective for electric ink adjustment mechanisms.

[Conventional technology]

As is well known, the inking device in multicolor offset printing machines for letterpress and lithographic printing uses a row of rollers to knead and spread the ink supplied from the ink fountain, and ink a few μm onto the surface of the form roller that contacts the plate cylinder at the final stage. The ink is applied from between the fountain roller and the bottom plate as the roller rotates, and the applied amount (finally applied on the surface of the roller) is As a means of determining the ink thickness of
A device configuration is adopted that adjusts the roller gap using the bottom plate.

Furthermore, in order to adjust the amount of ink spread, it is necessary to adjust the distribution in the width direction of the plate cylinder depending on the ink coverage on the plate cylinder, that is, the color tone distribution of the design pattern on the printing paper. In this method, the bottom plate is divided into a large number of zones and the bottom plate portions corresponding to these zones are adjusted independently.

To this end, in the conventional device, the device is constructed of a thin spring band plate, and the bottom plate is partially pushed up by operating individual screw shafts arranged at intervals corresponding to the zones on the back side of the device. However, recently, in order to more precisely determine the accuracy of bottom plate adjustment for each zone, the bottom plate has been separated into zone widths corresponding to the individual screw shafts, so that these zones can move independently. has been proposed.

On the other hand, the adjustment of the screw shaft is performed by magnetically recording the data of the average drawing density of each zone of the printing plate in advance, and using an automatic or manual remote control device to adjust the ink distribution to the appropriate level based on the data. Ink presetting means, which is adjusted from the start of printing, is widely used.

[Problem that the invention attempts to solve]

By the way, according to the remote control of the screw shaft in the ink presetting means as described above, the initial position of the screw shaft can be determined based on the data of the length of the screw shaft that is fed out, that is, the amount of ink spread, calculated by plate analysis. Since it is necessary to install sensors such as encoders to actually measure the bottom plate (for example, the fully closed state of the bottom plate) and the feeding position, etc., it is necessary to install sensors such as encoders to measure the feeding position of each screw shaft, including the signal circuit from these sensors and the power supply circuit to the motor. Five or six lead wires are wired for each device, and as a result, the bundle of wires from the feeding device for each zone to the central control unit such as the computer control device becomes thicker.
It was extremely difficult to maintain and manage the layout and configuration. Furthermore, since the accuracy of adjusting the amount of ink by adjusting the screw shaft is directly affected by the accuracy of position detection by the sensors, it is necessary to increase the detection accuracy by these sensors as much as possible.

When using Hall elements (switching elements with an IC configuration) as such sensors, there is an advantage that they are non-contact sensors, but as shown in Figure 3, these elements have an operating point p ₁ and a release point p ₂ relative to the near magnetic field. There is a hysteresis between the air gap s (about 500μ
(degree) becomes the inactive zone, so if it is used as is, it will not be able to function as this type of position detection sensor.

Therefore, in the automatic ink amount adjustment mechanism, the present invention simplifies the wiring in the adjustment screw shaft feeding device for each zone, which is optimal for the weighing device configuration and allows high adjustment accuracy to be obtained. The purpose is to provide equipment.

[Means for solving problems]

According to the present invention, the above-mentioned object can be achieved by an electric ink adjustment mechanism in which a bottom plate, which is located between the ink fountain roller and regulates the application gap, is operated by a screw shaft delivery device connected to a small motor operated by a positioning signal, a gear is provided which can move axially integrally with the screw shaft in conjunction with the screw shaft, a position detection sensor consisting of a Hall element is provided in the rotation area of a magnet arranged on the periphery of the gear, and the ink adjustment device is configured to determine the adjustment reference position by the delivery device based on the sensor signal.

[Effect]

The small motor that controls the feeding device is a direct current motor that can rotate in forward and reverse directions, and its reverse rotation is controlled by the power supply circuit to drive the screw shaft of the feeding device toward a reference position (for example, the bottom plate fully closed position). In conjunction with this operation, the gear rotates and moves toward the position detection sensor.

When the gear approaches the sensor and the magnets disposed around it rotate and cross the sensor surface in a direction that intersects, the magnetic field strength of the magnet reaches an approach area (operation point area) sufficient to activate the sensor. As a result, the power supply to the small motor is stopped in response to an activation signal from the sensor, and the screw shaft and gear are placed in the reference position.

In such a reference position determination operation, as shown in FIG. 4, which shows the relative change position between the magnet M and the sensor u across its magnetic field F, the gear (magnet M) interlocking with the screw shaft changes the sensor U on the diagram
The distance (several tens of μ) in which the moving distance (between one pitch of the screw shaft) in the direction away from the sensor (position U ₁ in the figure) retreats outside the operating point p ₂ area
As described above, the movement condition for operating the sensor u at the closest position to the sensor u is the turning angle of the magnet, that is, several tenths of the distance between one pitch of the movement.
Moreover, the dead zone based on the hysteresis of the sensor u is also within the operating point p ₂
The gear and its magnet are in an extremely narrow range (the range of the gear's small turning movement range), which is the range of the area l ₁ and the area _{l 2} leading to the release point p ₁ plus the sensing surface area l 3 of the sensor u. It acts as an enlarged positioning element for the movement of the screw shaft in the feeding direction.

The screw shaft, whose reference position has been determined, adjusts the bottom plate by moving the screw shaft from the reference position as a starting point by a length that corresponds to the drive amount of a small motor that is activated by a positioning signal from the outside.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is a plan view thereof. A small motor 2 is attached to a substrate 1, and a fixed screw shaft 4 is arranged parallel to a drive shaft 3 of the motor 2. The drive shaft 3 is attached to the screw shaft 4.
A gear 5 that meshes with the gear 5 is screwed together so as to be movable in the axial direction.

On the other hand, a sensor 6 made of a Hall IC circuit element is fixed to the substrate 1, and its tip sensing portion is connected to a gear 5.
It faces the rotation area of the magnet 7 buried in the side of the magnet.

Further, the gear 5 is provided with a gear 9 integrated with a screw shaft 8 for adjusting the gap between the ink fountains by pushing up the bottom plate (not shown) of the ink fountain, etc., and interlockingly connected to the bearing plate 10 and the base plate 1. I have let you. Others, 11
12 is a manual rotation knob provided at one end of the drive shaft 3, and 12 is a tachometer, which is composed of a magnet and a fixed Hall element arranged on a rotation plate 13 provided at the other end of the drive shaft 3. be.

Further, a circuit component 14 is attached to the board 1, which functions as an input/output mechanism for a central control section consisting of a microcomputer, etc., and is used to analyze operating signals from the central control section, position signals from the sensor 6, and the counting section. It is designed to perform arithmetic processing, etc. of the counter signal from 12.

According to the embodiment having the above-mentioned configuration, this is used by being attached to the screw shaft 8 for each zone of the ink fountain bottom plate, which is independently separated for each vertically divided zone of the printing plate, or which is continuous.

At the time of ink presetting, the adjustment device at the end of the zone receives a positioning signal calculated from the data of the average print density of each zone read by the central control section. The motor 2 is reversely rotated to rotate the gear 5 meshed with its drive shaft 3. With this operation, the gear 5 moves to the left in FIG. 1 due to the pitch feed of the fixed screw shaft 4, and approaches the sensor 6.
As the gear 5 approaches the sensor, the sensor 6 is activated when the magnetic flux density display section, which is the operating point p ₂ of the magnet 7 that has arrived from the rotating direction, reaches the position of the sensor u as shown in FIG. to reverse the previous switch state (for example, from ON to
OFF state).

The circuit component 14 that received this sensor signal is
The current power supply to motor 2 is stopped, and the motor operation is stopped.

Therefore, the gear 5 stops its movement, but
If the motor continues to rotate due to inertial movement after the motor stops, the magnet 7 will move to the sensor u in Figure 4.
When an overrun condition occurs that exceeds position 2 (release point p ₁ ), motor 2 operates in the forward direction when sensor 6 is reversed again (ON state).
The reversal operation of directing the magnet 7 toward the sensor 6 is repeated on the opposite side, resulting in l ₁ + l ₂ +
l Stop at a position within the range of ₃ .

Using this stop position as the reference position of the gear 5, that is, the screw shaft 7, the circuit component 14 then controls the motor 2 based on the motor rotation speed information in the positioning signal.
The motor 2 is started by applying a current in the direction of forward rotation to the motor 2, and while subtracting the count signal from the tachometer 12 in operation from the information value, when the rotation speed reaches the given information value, the motor 2 is started. Discontinue power supply to. As a result, the gear 5 and screw shaft 8 are moved from the reference position by the number of rotations of the motor 2 given by the positioning signal, so that the ink fountain bottom plate pushed by the screw shaft 8 is at the reference position. (For example, the fully closed position) is moved in the opening direction by an amount based on the information of the positioning signal, and the width of the ink application slit is thereby adjusted.

It is also possible to perform the reference positioning and position adjustment by motor drive by operating the manual rotary knob 11.

By providing the circuit configuration unit 14 in this adjustment device with a function of synchronizing signal input and output with the central control unit, the signal circuits in each circuit configuration unit 14 of the adjustment device for each zone can be configured in series. possible, and under such a configuration, each regulating device only needs to be wired with a three-wire power supply circuit for forward and reverse rotation of the motor and a signal circuit between adjacent devices, and therefore the ink control unit can be connected to the central control unit for centralized control. It becomes possible to configure the wire bundle heading toward the device section into an extremely thin bundle consisting of four or five wires.

[Effect of idea]

As described above, the device of the present invention performs electric adjustment in the inking device of a printing machine, and
When detecting the initial adjustment reference position of the screw shaft that presses the bottom plate of the ink fountain for adjustment using a positioning sensor consisting of a Hall element, a magnet placed around a gear that integrally interlocks with the screw shaft is attached to the sensor. Since it is arranged so that it faces from the turning area, it is possible to take a large amount of displacement of the magnet corresponding to the pitch at which the screw shaft is fed out. In order to deal with this, the influence of the hysteresis on the movement of the screw shaft is minimized by configuring the magnetic field cross-cutting method using the magnet rotation movement.
The positioning accuracy by the sensor can be extremely improved. Moreover, by adjusting the ink amount by controlling the amount of screw shaft extension from the reference position, this control can be performed remotely by energizing the signal processing circuit component in the adjustment device section arranged for each zone of the printing plate. The configuration of the ink processor using the central control unit becomes possible with a very limited number of wiring lines.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of the device of the present invention;
FIG. 2 is a plan view, FIG. 3 is a diagram showing the operating characteristics of the sensor used in the device of the present invention, and FIG. 4 is a diagram showing the relative positional relationship between the sensor and its sensing body in the device of the present invention. 2...Motor, 3...Drive shaft, 4...Fixed screw shaft, 5...Gear, 6...Sensor, 7...Magnet,
8...screw shaft.

Claims (1)

[Claim for Utility Model Registration] An electric type in which the bottom plate, which is located between the ink fountain roller and regulates the printing gap, is operated by a screw shaft feeding device connected to a small motor activated by a positioning signal. In the ink adjustment mechanism, a DC motor capable of forward and reverse rotation is arranged on the substrate as the motor, a fixed screw shaft is arranged parallel to the drive shaft of the motor, and the screw shaft meshes with the drive shaft. The gears are screwed together so as to be movable in the axial direction, and a distance detection sensor made of a Hall IC circuit element is disposed on the substrate, and when the gear rotates in one direction, the sensor approaches the sensor, and when the gear rotates in one direction, the sensor approaches the sensor. a magnet that faces and separates from the sensor when rotated to is disposed on a side surface of the gear; a second gear that is integral with the screw shaft that adjusts the gap between the bottom plate is meshed and connected to the gear; An ink adjusting device for a printing machine, characterized in that when a magnet approaches the ink adjusting device for a printing machine, power supply to the motor is stopped in response to a signal from the sensor, and a reference position for adjustment by the feeding device is determined.