JP3059067B2 - Offset printing device with dampening water amount detecting mechanism and dampening water amount detecting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset printing apparatus having a dampening water amount detecting mechanism, and more particularly to a method of mounting a dampening water amount detector.

[0002]

2. Description of the Related Art In an offset printing apparatus, an operator determines the amount of dampening water to be applied to a plate while checking the printing surface so that a high-quality printed matter is obtained. Need to hold. For this reason, the offset printing apparatus requires a dampening water amount detector for detecting the film thickness of the plate surface. In this dampening water amount detector, it is necessary to keep the distance between the dampening water amount detector and the printing plate at a predetermined distance in order to accurately detect the dampening water amount.

On the other hand, in detecting the amount of dampening water, a non-image area where ink does not adhere is selected as a detection point for detecting the amount of dampening water. The position of this non-image area changes depending on the plate to be set.

As described above, the slide bar set in parallel with the plate cylinder so that the amount of dampening water can be detected regardless of the position of the plate at any detection point while maintaining the distance to the plate surface accurately. There is known a dampening water amount detecting device provided so as to move the dampening water amount detector along the slide bar.

[0005]

However, the dampening water amount detecting device has the following problems.

Since the slide bar is fixed to the plate cylinder, it is necessary to perform maintenance such as cleaning the ink roller, attaching and detaching the plate to and from the plate cylinder, or attaching and detaching the ink foam roller. The slide bar gets in the way.

The present invention solves the above-mentioned problems, and it is possible to detect the dampening water amount regardless of the position of the plate at any detection point while maintaining the distance from the plate accurately. An object of the present invention is to provide a fountain solution amount detection device in an offset printing device with good workability.

[0008]

According to a first aspect of the present invention, there is provided an offset printing apparatus with a dampening water amount detecting mechanism, the printing mechanism in an offset printing apparatus having a plate cylinder, a safety cover for opening and closing the printing mechanism. Holding means for holding the safety cover at a predetermined position with respect to the plate cylinder when the safety cover is closed, a slide bar fixed to the safety cover, wherein the plate cylinder is closed when the safety cover is closed. A slide bar provided so as to be parallel to the axis of, the plate held by the plate cylinder, irradiating light,
A dampening water amount detector that receives light reflected by the plate and detects a dampening water amount based on the received light amount, and a dampening water amount detector movably provided along the slide bar. It is characterized by having.

According to a second aspect of the present invention, there is provided an offset printing apparatus with a dampening water amount detecting mechanism, further comprising a connecting cord storing means for storing a connecting cord of the dampening water amount detector, wherein the connecting cord is provided in the connecting cord storing means. And is housed in a telescopic shape.

According to a third aspect of the present invention, in the method for mounting a dampening water amount detector, the printing mechanism is covered with a safety cover so as to be openable and closable. The dampening water amount detector is attached to the safety cover so as to be freely movable in parallel and to be held at a predetermined position with respect to the plate cylinder.

According to a fourth aspect of the present invention, there is provided a jig in which a tip of the fountain solution detector is inserted and at least a part of the tip is in contact with a bottom surface, and the body is located on a side opposite to the bottom surface. An abutting portion provided in a protruding manner, wherein the abutting portion is in contact with the plate surface to keep a distance between the bottom surface portion and the plate surface at a predetermined distance, and connects the dampening water amount detector to an axial center of the plate cylinder. And a contact portion that is directed at a predetermined angle with respect to.

In the fountain solution amount detecting apparatus of the offset printing apparatus according to the present invention, when the irradiation start signal is received, the plate held by the plate cylinder is irradiated with light and reflected by the plate. A dampening solution amount detector that detects the amount of dampening solution based on the received light amount, an irradiation candidate position determining unit that inputs a non-image area of the plate held by the plate cylinder as an irradiation candidate position, Receiving a drive signal, rotating drive means for rotationally driving the plate cylinder, an irradiation surface formed by the dampening solution amount detector, and correction data storage means for storing a positional deviation between the irradiation candidate position as correction data, An irradiation start signal output unit that outputs an irradiation start signal to the dampening water amount detector so that irradiation is performed on the irradiation candidate position for each rotation cycle of the plate cylinder based on the correction data. And it said that there were pictures.

[0013] In the dampening water detection method in an offset printing apparatus of claim 6, held on a plate cylinder which is rotationally driven
The amount of dampening water based on the light reflected by the plate
Wetness in offset printing equipment using dampening water detector
A method for detecting an amount of water, comprising: a printing mechanism provided with the plate cylinder.
Is openably and closably covered with a safety cover and held by the plate cylinder.
Illuminates the plate and receives light reflected by the plate
And the amount of dampening water is detected based on the amount of received light.
When the detector is closed, the dampening solution
The amount detector is movable parallel to the axis of the plate cylinder,
And held at a predetermined position with respect to the plate cylinder.
Attach to the safety cover, determine the irradiation candidate position which is shifted by a predetermined rotation angle from the detection position of the dampening solution amount detector with respect to the rotation direction of the plate cylinder, and based on the rotation deviation angle, The amount of dampening water is detected at the irradiation candidate position while rotating the body.

[0014]

In the offset printing apparatus with a dampening water amount detecting mechanism according to claim 1, when the openable and closable safety cover is closed, the safety cover is held at a predetermined position with respect to the plate cylinder by the holding means. Is done. The slide bar is fixed to the safety cover, and the slide bar is parallel to the axis of the plate cylinder when the safety cover is closed. The dampening water amount detector is provided movably along the slide bar. Therefore, when the safety cover is closed , the dampening water amount detector is held at a predetermined position and is movable parallel to the axis of the plate cylinder. In a state where the safety cover is opened, the dampening water amount detector moves away from the printing mechanism together with the safety cover. Thus, the slide bar does not interfere with maintenance work or the like.

In the offset printing apparatus with a dampening water amount detecting mechanism according to a second aspect, the connection cord is stored in the connection cord storage means in a stretchable shape. Therefore, when the dampening water amount detector is moved, the connection cord can be smoothly moved without being entangled.

According to a third aspect of the present invention, the printing mechanism is covered with an openable / closable safety cover. When the safety cover is closed, the dampening water amount detector is movable in parallel with the axis of the plate cylinder, and the dampening water amount detector is held at a predetermined position with respect to the plate cylinder. A water detector is attached to the safety cover. Therefore, in a state where the safety cover is closed, the dampening water amount detector is held at a predetermined position and is movable in parallel to the axis of the plate cylinder. In a state where the safety cover is opened, the dampening water amount detector moves away from the printing mechanism together with the safety cover. This facilitates the work of the printing mechanism.

In the jig of the fourth aspect, the main body includes:
A tip of the dampening water detector is inserted and has a bottom surface with which at least a part of the tip contacts. Further, the contact portion is provided so as to protrude on the opposite side to the bottom portion of the main body, contacts the plate surface, and keeps a distance between the bottom portion and the plate surface at a predetermined distance. The dampening water amount detector is directed at a predetermined angle with respect to the axial center of the plate cylinder. Therefore, the distance between the tip of the dampening water amount detector and the printing plate is maintained at a predetermined distance only by contacting the tip of the dampening water amount detector with the bottom surface portion, and the dampening water amount detector is It can be oriented at a predetermined angle with respect to the axial center of the plate cylinder.

In the dampening water amount detecting device of the offset printing apparatus according to the present invention, when the rotation driving signal is further received , the rotation driving means rotates the plate cylinder. When the irradiation candidate position is inputted by the irradiation candidate position determining means, the correction data irradiation start signal output means outputs the correction data irradiation start signal for each rotation cycle of the plate cylinder based on the correction data stored in the correction data storage means. Then, an irradiation start signal is output to the dampening solution amount detector so that the irradiation candidate position is irradiated. Upon receiving the irradiation start signal, the dampening solution amount detector detects the dampening solution amount. Therefore, by simply inputting a non-image area portion as the irradiation candidate position by the irradiation candidate position determination means, detection is performed at this irradiation candidate position.

According to a sixth aspect of the present invention, there is provided a method for detecting the amount of dampening water in an offset printing apparatus, comprising the steps of:
The plate held by the plate cylinder covered with a safety cover so that it can be opened and closed freely
Irradiate light, receive the light reflected by the plate,
Damping water volume detection that detects the amount of dampening water based on the amount of light received
When the safety cover is closed, the dampening solution
The dispenser is movable parallel to the axis of the plate cylinder,
To be held in a predetermined position with respect to the plate cylinder,
It is attached to the safety cover. Therefore, the safety
With the cover closed, the dampening water amount detector
Position and parallel to the axis of the plate cylinder
It becomes movable. Also, with the safety cover open
The dampening water amount detector together with the safety cover
Move away from the printing mechanism. Thereby, the slide bar
Does not interfere with maintenance work. Further, with respect to the rotation direction of the plate cylinder, an irradiation candidate position that is shifted from the detection position of the dampening water amount detector by a predetermined rotation angle is determined, and based on the rotation shift angle, the plate cylinder is rotated while rotating. The amount of dampening water is detected at the irradiation candidate position. Therefore, at the irradiation candidate position shifted by a predetermined rotation angle from the detection position of the dampening water amount detector,
Since it is sufficient to determine the detection position, it is easy to determine the irradiation candidate position.

[0020]

An embodiment of the present invention will be described with reference to the drawings. The attachment of the dampening water detector 20 to the offset printing apparatus will be described with reference to FIG. As shown in FIG.
The dampening water detector 20 is attached to an openable / closable cover 25. Therefore, maintenance and inspection of the printing plate 13 can be easily performed only by opening the cover 25 before starting printing.
The cover 25 is positioned by the positioning pins 30.
Therefore, the distance d between the dampening water detector 20 and the plate 13 is determined.
2 can be held accurately.

The damping water amount detector 20 is mounted on a slider 24 as shown in FIG. The slider 24 is movable in the direction of arrow 26 along the support bars 11a and 11b. That is, by rotating the plate cylinder 5 or moving the slider 24, the amount of dampening solution in any part of the plate surface 13 can be detected.

In this embodiment, the positioning pins 30 serve as holding means, the support bars 11a and 11b serve as slide bars, and
The cover 25 corresponds to a safety cover.

FIG. 3 shows a fountain solution amount detecting device 22 using the fountain solution amount detector 20. In the dampening water amount detection device 22, it is necessary to select a non-image area portion, which is a region of the plate surface where ink is not applied, as a dampening water amount detection point. In this apparatus, an operator searches for a non-image area on the printing plate 13 and sets a detection point thereof, thereby detecting the dampening water amount.

The damping water amount detector 22 includes a damping water amount detector 20, a manual pointer 21, an angle correction value memory 43,
A controller 39, an adder / subtractor 34, an angle setter 35, a comparator 36, and a trigger output circuit 37 are provided. The manual pointer 21 is stored in the angle correction value memory 43.
And the angle of deviation θ from the dampening water amount detector 20 are stored as correction data.

In this embodiment, the controller 39, the adder / subtractor 34, the angle setting unit 35, and the comparator 3
6 and the trigger output circuit 37 constitute irradiation start signal output means. The angle correction value memory 43 corresponds to a correction data storage unit, and the manual pointer 21 corresponds to an irradiation candidate position determination unit.

Referring to FIGS. 2 and 3, the dampening water amount detecting device 2 will be described.
2 will be described. The operator looks into the printing plate 13 through the viewing hole 21a of the manual pointer 21,
The plate cylinder 5 is rotated to search for a non-image area. As shown in FIG. 2, the slider 24 is arranged in a lateral direction of the plate surface (axial direction of the plate cylinder 5).
Is moved, the manual pointer 21 integrated with the slider 24 moves in the lateral direction of the plate surface. The slider 24 is moved or the plate cylinder 5 is rotated until a non-image area that is deemed appropriate for detection is found. When a non-image area is found, the machine is stopped at that point. After stopping the machine, tighten the stopper bolt 23 shown in FIG.
The slider 24 is fixed.

After the setting is completed, the manual setting switch SW1 shown in FIG. In this way, the operator can set the plate cylinder 5
Is input as the irradiation candidate position.

The angle detector 32 includes an encoder 33 and an A / D converter. The encoder 33 is installed so as to be in phase with the plate cylinder 5 coaxially with the plate cylinder 5 or via a gear or a belt (not shown).
The angle detector 32 detects the angle data at the position and gives the angle data to the controller 39. The controller 39
The angle data 40 given from the angle detector 35 and the correction data given from the angle correction value memory 43 are
This is given to the angle setting device 35. When the manual setting signal is input in this manner, the angle setting unit 35 supplies the deviation angle θ
The value corrected by the minute is given.

Upon receiving the rotation drive signal, the plate cylinder 5 is driven to rotate by rotation drive means (not shown). The set angle data set and the detected angle data are compared by the comparator 36, and a signal is sent to the trigger output circuit 37 at each coincident timing. Trigger output circuit 37
Supplies a trigger signal of a detection point to the dampening water amount detector 20. The dampening water amount detector 20 detects the dampening water amount using the trigger signal as an irradiation start signal. Thus, every time the plate cylinder 5 makes one rotation, the dampening solution amount in the non-image area portion of the plate 13 set by the operator is detected.

In this embodiment, the displacement angle θ of the dampening water amount detecting device is stored in the angle correction memory 43 in advance. However, the manual pointer 21 may be configured so that the positional relationship with the dampening water amount detector 20 can be changed so that the shifted angle θ after the change can be input. With this configuration, the manual pointer 21 can be set at a position that is easy for the operator to see.

Referring to FIGS. 4 to 8, the dampening water amount detector 20 will be described.
A dampening water amount detection device 122 which is another dampening water amount detection device using the following will be described. The dampening water amount detection device 122 includes:
Similar to the dampening water amount detection device 22, the operator searches for a non-image area on the printing plate 13 and sets a detection point thereof, thereby detecting the dampening water amount at the detection point. It is.

FIG. 4 is an exploded perspective view of a slide mechanism portion of the dampening water amount detecting device 122. Also in this embodiment, a slide bar 111 is screwed to the cover 25 via a block 25a. Slide bar 11
A damping water detector 20 is movably attached to the slide bar 111 along the slide bar 111. Damping water detector 20
Will be described with reference to FIG. Metal fittings 128 and 129 are screwed to the bracket 127 so as to surround the slide bar 111. By tightening the stopper bolt 23, the bracket 127, the metal fitting 128, and the metal fitting 129 are fixed to the slide bar 111. The plate 130 is screwed to the bracket 127 so as to pass through the long hole 25b of the cover 25. At the tip of the plate 130, as shown in FIG.
The dampening water amount detector 20 is connected via the detector mounting bracket 132.
Is attached. The other end of the plate 130 has a slot 13
0a is provided. As shown in FIG. 5, the manual setting pointer 21 is attached between the dampening water amount detector 20 and the plate 130 so as to be sandwiched therebetween. The connection cord 115 of the dampening water detector 20 is curled as shown in FIG. The connection cord 115 is stored in the connection cord receiver 114. Connection cord receiver 114
4, a rod 116 is screwed as shown in FIG. 4, and is wound in a curl shape by the rod 116. The connection cord receiver 114 is screwed to the cover 25. Since the connection cord 115 is wound in a curled shape in this manner, the dampening water amount detector 20 can move along the slide bar 111 without the connection cord 115 being entangled.

The shape of the connection cord 115 will be described with reference to FIG. As shown in FIG.
5 is a non-curl portion 115a on the dampening water amount detector 20 side and a curl portion 115b connected to the non-curl portion 115a.
Having. The length L1 of the non-curled portion 115a is about half the length of the slide bar 111, and the length L2 of the curled portion 115b is also about half the length of the slide bar 111. When the dampening water amount detector 20 moves in the direction of arrow 125, FIG.
As shown in B, the curl portion 115b extends. Therefore, the dampening water amount detector 20 can move in the direction of the arrow 125 without the connection cord 115 being entangled. Further, since the non-curl portion L1 having a length of about half the length of the slide bar 111 is provided, as shown in FIG. 6C, the non-curl portion 115a and the curl portion 115b overlap each other, so that It can move in the direction of arrow 126. The length L2 of the curled portion 115b is about half the length of the slide bar 111, so that the curl portion 115b can be expanded and contracted in a state shown in FIG. 6C (a state in which the curled portion 115b is most extended). What is necessary is just to determine the winding diameter of the part 115b.

As shown in FIG. 4, when the slide bar 111 is attached to the cover 25, the damping water amount detector 20 is not properly attached to the plate 13 due to lack of accuracy of the cover 25 or a metal fitting for mounting the damping water amount detector. May not be set in a proper state. Therefore, in the present embodiment, FIGS.
The positioning of the slide bar 111 and the dampening water amount detector 20 was performed using jigs 141, 142, and 150 shown in FIG. In addition, about the cover 25, the dampening water amount detection device 2
As in the case of 2, positioning is performed by the positioning pins 30. When the cover 25 is closed, the magnet 17 shown in FIG.
At 0, it is fixed to a frame (not shown) of the offset printing apparatus.

For positioning the slide bar 111, jigs 141 and 142 shown in FIG. 7 are used. Positioning pins (not shown) are provided on the frame of the offset printing apparatus to which the detection device 122 is attached. The positioning pins have through holes 141 of the jigs 141 and 142.
a, 142a, so that the jigs 141, 1
42 is set in the frame.

For positioning in the directions of arrows 145 and 146, gaps S1 and S2 between blocks 141c and 142c are used.
Is adjusted so as to have a predetermined interval with a shim interposed between the slide bar 111 and the block 25a. Further, regarding the positioning in the directions of arrows 143 and 145, the mounting holes 1 of the elongated slide bar 111 are formed so that the gap between the slide bar 111 and the jigs 141 and 142 is eliminated.
Adjustment is made at 11a and 111b. Thereby, the slide bar 111 is positioned with respect to the plate cylinder 5. After the slide bar 111 is positioned with respect to the plate cylinder 5, the jig 1
Remove 41.

Next, the positioning of the dampening water amount detector 20 with respect to the plate cylinder 5 will be described. For this positioning, a jig 150 shown in FIGS. 8 and 9 is used. As described below, the jig 150 can move the dampening water amount detector 20 toward the center of the plate cylinder 5 and set the distance d2 between the dampening water amount detector 20 and the plate 13 to a predetermined value. Can be kept at a distance.

As shown in FIG. 8, the jig 150 is
51 and a pair of rod-shaped members 152, 152 that are abutting portions
It has. The main body 151 has a bottom surface portion 151a into which the tip of the dampening water detector 20 is inserted and at least a part of which is in contact with the tip. A pair of bar-shaped members 152, 152 are provided on the opposite side of the bottom surface portion 151a of the main body 151 so as to protrude. In this embodiment, as shown in FIG. 9, one surface 151c of the main body 151 is
52 is attached, the rod-shaped member 152,
152 is provided so as to protrude from the main body 151. In addition, the rod-shaped members 152, 152 were attached to the main body 151 by screwing (not shown) by partially milling the circumferential portion in the same shape. The bottom 151
About the depth of a, the plate 13
Is determined such that the distance d2 between the dampening water amount detector 20 and the plate 13 is maintained in a state where the contact is made.

The bar 13 of the jig 150 is mounted on the plate 13.
The damping solution detector 20 is set on the jig 150 in this state. While temporarily held by the leaf spring 151d, the dampening water amount detector 20 is fixed to the detector mounting bracket 132 using the screw hole 20a. As described above, since the detector mounting bracket 132 is provided with the long hole 132a, the damping water amount detector 20 can be directed to the center of the plate cylinder 5. 5, the other end of the plate 130 is provided with a long hole 130a. By loosening the screw 136, the distance between the dampening water amount detector 20 and the plate surface can be adjusted. Thus, the positioning in the directions of arrows 155 and 156 and the positioning in the directions of arrows 153 and 154 can be easily performed by the jig 150. After the dampening water amount detector 20 is positioned with respect to the plate cylinder 5, the jig 150 is removed.

As shown in FIG. 10, the damping water amount detector 20 can be attached to the cover 25 in an oblique direction. Since such an attachment method is possible, even if it is a multicolor printing apparatus (for example, four-color printing), the damping water amount detector 20 can be attached without limiting the attachment location. In this case, the auxiliary fitting 13 as shown in FIG.
3 may be used. In addition, similarly to the above embodiment, the plate 130 is provided with a long hole 130a,
By loosening 36, the distance between the dampening water amount detector 20 and the plate surface can be adjusted. Further, the slide bar 111 may be attached in the same manner as shown in FIG. In this case, the slide bar 111 is used as the dampening water amount detector 2
Since it is disposed obliquely above zero, the manual setting pointer 21 may be attached to the lower part of the dampening water amount detector 20 as shown in FIG. In this embodiment, the connection cord receiver 114 is exposed not to the inside of the cover 25 but to the outside. However, this is due to a space problem, and is not particularly limited thereto. As in the example, it may be provided inside the cover 25.

The method by which the operator uses the manual pointer 21 to search for a detection point and the method for detecting the amount of dampening water at this detection point are the same as those in the above embodiment, and will not be described.

The mounting position of the dampening water detector 20 is not limited to the position shown in the above embodiment. For example, FIG.
As shown in FIG. 1, an ink roller group 27, a water roller 28,
In relation to blanket cylinder 29, 220a, 220b, or 2
20c may be attached to any position. By arranging the dampening water amount detector 20 at these positions and inputting the detected value to the control device, the detected dampening water amount can be used as an input for the dampening water amount control device. .

Further, 220a, 220b, 220c
By providing detection devices at all three positions, a change in the plate surface in the ink roller group 27 or a change in the plate surface in the printing state can be detected with high resolution.

In this embodiment, the plate spring 151d for temporarily holding the damping water detector 20 in the jig 150 is used.
Is provided. As a result, the state where the dampening water amount detector 20 is positioned is temporarily held, so that the dampening water amount detector 20
Setting is easy. The temporary holding means is not limited to this, and may have another shape.

In this embodiment, a pair of rod-like members 152, 152 are employed as the abutting portions.
50 can be manufactured accurately and easily. The contact portion is not limited to this, and may have a shape corresponding to the plate cylinder on which the plate is mounted.

In this embodiment, by using the jig 150, the dampening water amount detector can be directed to the axial center of the plate cylinder. However, the present invention is not limited to this. If the jig 150 is adjusted so that a predetermined angle with respect to the axis of the plate cylinder is formed, the jig 150 can be oriented at a predetermined angle with respect to the axis of the plate cylinder.

In this embodiment, the connection cord 1
The connection cord 115 is formed in a stretchable shape by forming the connection cord 115 into a curl shape. However, the extendable shape of the connection cord 115 is not limited to the curl shape,
The connection cord 115 is not entangled, and
Any shape may be used as long as it is movable. For example, the shape may be a broken shape.

[0048]

In the offset printing apparatus with a dampening water amount detecting mechanism according to the first aspect, when the safety cover that can be opened and closed is closed, the safety cover is held at a predetermined position with respect to the plate cylinder by holding means. Is held. The slide bar is fixed to the safety cover, and is parallel to the axis of the plate cylinder when the safety cover is closed. The dampening water amount detector is provided movably along the slide bar. Therefore, when the dampening water amount detector is closed with the safety cover, the dampening water amount detector is held at a predetermined position, and is movable parallel to the axis of the plate cylinder. Further, when the safety cover is opened, the dampening solution detector separates from the printing mechanism together with the safety cover. Thus, the slide bar does not interfere with the operation of the printing mechanism. Therefore, it is possible to provide a dampening water amount detection device in an offset printing apparatus that can detect a dampening water amount and can easily work regardless of the position of a detection point in a plate while accurately maintaining a distance from the plate surface. can do.

In the offset printing apparatus with the dampening water amount detecting mechanism according to the second aspect, the connection cord storing means stores a connection cord having a stretchable shape. Therefore, the connection cord does not get tangled when the dampening water amount detector is moved. Accordingly, it is possible to provide a dampening water amount detecting device in which the dampening water amount detector can be moved and the connection cord does not become entangled in detecting the dampening water amount.

According to a third aspect of the present invention, the printing mechanism is covered with an openable / closable safety cover. When the safety cover is closed, the dampening water amount detector is movable in parallel with the axis of the plate cylinder, and the dampening water amount detector is held at a predetermined position with respect to the plate cylinder. A water detector is attached to the safety cover. Therefore, in a state where the safety cover is closed, the dampening water amount detector is held at a predetermined position and is movable in parallel to the axis of the plate cylinder. Also, when the dampening water amount detector opens the safety cover,
At the same time, it separates from the printing mechanism. This allows
The operation of the printing mechanism is facilitated. Therefore, it is possible to provide a method for detecting the amount of dampening water in an offset printing apparatus that can detect the amount of dampening water and can easily work with any plate at any detection point while accurately maintaining the distance to the plate surface. can do.

In the jig of the fourth aspect, the main body is
A tip of the dampening water detector is inserted and has a bottom surface with which at least a part of the tip contacts. Further, the contact portion is provided so as to protrude on the opposite side to the bottom portion of the main body, contacts the plate surface, and keeps a distance between the bottom portion and the plate surface at a predetermined distance. The dampening water amount detector is directed at a predetermined angle with respect to the axial center of the plate cylinder. Therefore, the distance between the tip of the dampening water detector and the plate surface can be maintained at a predetermined distance, and the dampening water detector can be oriented at a predetermined angle with respect to the axial center of the plate cylinder. Thereby, the mounting of the dampening water amount detector becomes accurate and easy.

In the dampening water amount detecting device in the offset printing apparatus according to a fifth aspect, when a rotation driving signal is received, the rotation driving means rotates the plate cylinder. When the irradiation candidate position is inputted by the irradiation candidate position determining means, the correction data irradiation start signal output means outputs the correction data irradiation start signal for each rotation cycle of the plate cylinder based on the correction data stored in the correction data storage means. In order to irradiate the irradiation candidate position, for the dampening water amount detector,
An irradiation start signal is output. Upon receiving this irradiation start signal,
The fountain solution amount detector detects a fountain solution amount. Therefore, by simply inputting a non-image area portion as the irradiation candidate position by the irradiation candidate position determination means, detection is performed at this irradiation candidate position. This makes it possible to provide a dampening water amount detecting device in which the detection position can be easily determined.

According to a sixth aspect of the present invention, in the method for detecting the amount of dampening water in the offset printing apparatus, an irradiation candidate position which is deviated from the detection position of the dampening water amount detector by a predetermined rotation angle with respect to the rotation direction of the plate cylinder is determined. And, based on the rotation deviation angle,
A dampening solution amount is detected at the irradiation candidate position while rotating the plate cylinder. Therefore, since the detection position may be determined at the irradiation candidate position that is shifted from the detection position of the dampening water amount detector by a predetermined rotation angle, the irradiation candidate position is easily determined.
This makes it possible to provide a dampening solution amount detecting method in which the detection position can be easily determined.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method of mounting a dampening water amount detector 20 according to an embodiment of the present invention.

FIG. 2 is a view of FIG. 1 as viewed from the direction of arrow A.

FIG. 3 is a dampening water amount detecting device 2 according to one embodiment of the present invention.
2 is a functional block diagram of FIG.

FIG. 4 is an exploded perspective view of main components for describing a method of mounting the damping water amount detector 20 in the damping water amount detection device 122.

FIG. 5 is a diagram for explaining a method of mounting the dampening water amount detector 20 in the dampening water amount detection device 122.

FIG. 6 is a diagram for explaining the expansion and contraction state of the connection cord 115.

FIG. 7 is a perspective view showing a jig 141.

FIG. 8 is a perspective view showing a jig 150.

FIG. 9 is a sectional view showing a jig 150.

FIG. 10 is a diagram for explaining another mounting method of the dampening water amount detector 20 in the dampening water amount detection device 122.

FIG. 11 is a diagram for explaining another mounting method of the dampening water amount detector 20.

[Description of Signs] 11a ··· support rod 11b ··· support rod 20 ··· dampening water amount detector 21 ··· manual setting pointer 25 ··· cover 30 ··· positioning pin 34 · ... Addition / subtraction unit 35 ... Angle setting unit 36 ... Comparator 37 ... Trigger output circuit 39 ... Controller 43 ... Angle correction value memory 70 ... Switching unit 72 ···· Water motor speed setting device 74 ··· Water amount setting device 75 ··· PID 76 ··· Motor controller 150 ··· Jig 151 ··· Main body 152 ··· Bar member

Continuation of the front page (56) References JP-A-60-196349 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41F 33/00 B41F 7/24 B41F 13/42 B41F 33 / 10 B41F 33/14

Claims (6)

(57) [Claims] 1. A printing mechanism in an offset printing apparatus having a plate cylinder, a safety cover for opening and closing the printing mechanism, and when the safety cover is closed, the safety cover is moved to a predetermined position with respect to the plate cylinder. Holding means for holding the position, a slide bar fixed to the safety cover, a slide bar provided to be parallel to the axis of the plate cylinder when the safety cover is closed, A dampening water amount detector that irradiates light to the held plate, receives light reflected by the plate, and detects a dampening water amount based on the received light amount, the dampening water amount detector being disposed along the slide bar. And a fountain solution amount detector movably provided. An offset printing apparatus with a fountain solution amount detection mechanism. 2. The offset printing apparatus with a dampening water amount detecting mechanism according to claim 1, further comprising a connection cord storing means for storing a connection cord of said dampening water amount detector, wherein said connection cord is said connection code storing means. An offset printing apparatus with a dampening water amount detection mechanism, wherein the offset printing apparatus is housed in a stretchable shape. Irradiating the plate held by the plate cylinder with light;
A method for receiving a light reflected by the plate, and mounting a dampening water amount detector for detecting a dampening water amount based on the received light amount to an offset printing apparatus having a printing mechanism unit having a plate cylinder, When the printing mechanism is covered with a safety cover so as to be openable and closable, and when the safety cover is closed, the dampening solution amount detector is movable in parallel to the axis of the plate cylinder, and is movable with respect to the plate cylinder. So that it is held in place,
A dampening water detector mounting method, wherein the dampening water detector is attached to the safety cover. 4. A jig for positioning a dampening water amount detector with respect to the offset printing apparatus according to claim 1, wherein a tip of the dampening water amount detector is inserted, and at least a part of the tip is inserted. A main body having a bottom surface portion that is in contact with the main body, a contact portion provided so as to protrude from the bottom surface portion of the main body on a side opposite to the bottom surface portion, the main body contacting the plate surface, and determining a distance between the bottom portion and the plate surface And a contact portion for keeping the distance of the dampening water amount detector at a predetermined angle with respect to the axial center of the plate cylinder. 5. An offset with a dampening water amount detecting mechanism according to claim 1.
In the printing apparatus, further, irradiation candidate position determining means for inputting a non-image area of the plate held on the plate cylinder as irradiation candidate positions, a rotation driving means for receiving a rotation drive signal and rotating the plate cylinder, An irradiation surface formed by the dampening water amount detector, a correction data storage unit that stores a displacement between the irradiation candidate position as correction data, based on the correction data, for each rotation cycle of the plate cylinder,
An irradiation start signal output unit that outputs an irradiation start signal to the dampening water amount detector so that the irradiation is performed at the irradiation candidate position. apparatus. 6. Reflection by a plate held by a rotationally driven plate cylinder
Fountain solution detector that detects the amount of fountain solution based on the reflected light
Of detecting dampening water in an offset printing apparatus using a printer
In the above , the printing mechanism unit having the plate cylinder is opened and closed freely with a safety cover.
Cover, and irradiate the plate held by the plate cylinder with light, and
Receives the reflected light, and based on the amount of received light, the amount of dampening water
The dampening water amount detector to close the safety cover
Occasionally, the dampening water detector is positioned with respect to the axis of the plate cylinder,
Moveable in parallel and at a predetermined position with respect to the plate cylinder
Attached to the safety cover so as to be held in the direction of rotation of the plate cylinder, the irradiation position determined by a predetermined rotation angle from the detection position of the dampening water amount detector is determined, the rotation deviation angle And detecting the dampening water amount at the irradiation candidate position while rotating the plate cylinder based on the method.