JPH065167Y2 - Printing pressure display of rotary printing press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a printing pressure display device for displaying a printing pressure acting between a plate cylinder and an impression cylinder during printing in a rotary printing press.

[Conventional technology]

In a rotary printing machine, particularly an intaglio printing machine, during printing on paper passing between the plate cylinder and the impression cylinder, a large printing pressure acts as a printing force by setting the center-to-center distance between both cylinders, and The reaction force acts on the bearing portions of both barrels. As a result, the packing attached to the peripheral surface of the impression cylinder becomes thin or loses elasticity, which may cause printing failure. In addition, excessive bending stress may occur in the body end shaft, resulting in breakage accidents and bearing damage.

[Problems to be solved by the invention]

However, in the conventional intaglio printing machine, a device for displaying the printing pressure between the intaglio cylinder and the impression cylinder is not provided, and since it is not possible to know the excessive printing pressure, there is a possibility that an accident cannot be avoided in many cases. Development of a display device was requested.

The present invention has been made in order to meet such a demand, and an object thereof is to provide a printing pressure display device capable of quantitatively and accurately displaying printing pressure.

[Means for solving problems]

In order to achieve such an object, in the present invention, a strain gauge for detecting compressive strain is attached to a frame surface adjacent to a bearing fitted on the frame by pivotally supporting an end shaft of a cylinder to which a printing pressure is applied. did.

[Action]

When a printing pressure is applied between the intaglio cylinder and the impression cylinder during the printing operation, a compressive stress is generated in the strain gauge and the strain gauge is distorted. Therefore, the magnitude of the printing pressure can be known by displaying the strain amount.

〔Example〕

1 to 5 show an embodiment of a printing pressure display device according to the present invention. FIG. 1 is a schematic front view of an intaglio printing machine which carries out this, and FIG. 2 is a side view of an intaglio cylinder and an impression cylinder. FIG. 3 is a block diagram, FIG. 4 is a relational diagram of strain amount and time during a printing operation, and FIG. 5 is a cylinder arrangement diagram of an intaglio printing machine embodying the present invention. In the figure, bearings 4 and 5 are fitted to the left and right frames 2 and 3 of the intaglio printing machine 1, respectively, and the intaglio cylinder 6 has shafts 6a and 6 at both ends attached to these bearings 4 and 5, respectively.
b is pivotally supported. And on the peripheral surface of this intaglio cylinder 6, 3
A plurality of intaglio plates are mounted with their both ends gripped by a gripping device in the notch 6c shown in FIG. Also, the bearing 4,
5, eccentric bearings 7 and 8 in which an outer peripheral core and an inner hole core are eccentric are fitted to the bearing holes of the frames 2 and 3, and the impression cylinder 9 has both end shafts thereof. 9a and 9b are axially supported by eccentric bearings 7 and 8. Packing made of cardboard or blanket is attached to the peripheral surface of the impression cylinder 9 with its both ends gripped by a gripping device in a notch 9c shown in FIG. Then, by rotating the left and right eccentric bearings 7 and 8 with a detaching mechanism (not shown), the impression cylinder 9 moves in parallel in the radial direction and is pressed against the intaglio cylinder 6 or separated from the intaglio cylinder 6. It is configured to be attached and detached, and a printing pressure acts between the cylinders 6 and 9 by pressure contact. Another transfer cylinder 1 is attached to the transfer cylinder 10 that is in contact with the intaglio cylinder 9.
1 are in contact with each other, and a swing device 12 and a difference plate 13 are provided near the transfer cylinder 11. A pair of left and right paper ejection chains 1 is provided between the sprocket coaxial with the paper take-up cylinder that is in contact with the impression cylinder 9 and the sprocket of the paper ejection device (not shown).
Five are stretched. Further, the intaglio cylinder 6 has an inking device 1
The thickening roller 17 of No. 6 and the wiping roller 19 of the wiping device 18 are in contact with each other.

With such a configuration, the paper sent out onto the difference plate 13 by the paper feeding device passes through the transfer device 11 and 10 from the swing device 12, and is then provided in the notch 9c of the impression cylinder 9. It is replaced and transported. On the other hand, ink is supplied to the intaglio surface of the intaglio cylinder 6 by the inking roller 17, and the excess ink adhering to the areas other than the image indentations of this ink is wiped off by the wiping roller. A pattern is formed. As a result, the pattern on the intaglio surface is transferred to the paper passing between the impression cylinder 9 and the intaglio cylinder 6 while a large printing pressure is applied by both cylinders 6 and 9.
The paper thus printed is gripped by the claws of the paper discharge chain 15 and conveyed and discharged as the paper discharge chain 15 travels.

The intaglio printing machine configured as described above is provided with a printing pressure display device that detects and displays the compressive strain of the frame due to the printing pressure applied to the paper by the drums 6 and 9. That is, the bearing 5 that supports the end shaft 6b of the intaglio cylinder 6
Strain gauges 20 and 21 are attached to both front and back surfaces of the frame 3 at a position close to the lower side which is the printing pressure compression side, and compressive strain of the frame 3 due to bending of the end shaft 6b by the printing pressure. It is configured to detect and emit a signal. A dynamic strain measuring device 22 and a recording device 23 are connected in series to the strain gauges 20 and 21 as shown in the block diagram of FIG.
The compressive strains ε ₁₂ + ε ₁₃ detected by 0 and 21 are displayed on the recorder 23 through the dynamic strain measuring device 22. In FIG. 4, the horizontal axis represents time t _{1 and the} vertical axis represents strain amount ε =
FIG. 4 is a diagram showing ε ₁₂ + ε ₁₃ , and as shown in FIG. 2, when the notches 6c and 9e are in contact with each other, the printing pressure is released, so that the strain amount diagram is shown in FIG. The waveform looks like this. In addition, although only the strain gauge 20 may be used,
The strain amount is added by adding the strain gauge 21 on the front side of the frame 3, the output is increased, and the measurement accuracy is increased.

Now, the strain gauge 24 is attached also to the end shaft 6b, and the impression pressure is measured while changing the impression pressure from the light impression pressure to the strong impression pressure by moving the impression cylinder 9 in parallel as described above. The strain of the strain gauges ₂₀ , 21, 24 is ε ₂₀ ,
Assuming ε ₂₁ and ε ₂₄ , ε ₂₀ : ε ₂₁ = 3: 1 due to the linear relationship between ε ₂₄ and ε ₂₀ and ε ₂₁ . Quantitatively, ε ₂₄ = 65 to 120 × 10 ⁻⁶ , and ε ₂₀ = 10 to 25
It was × 10 ⁻⁶ , and the measurement was possible with sufficient accuracy.

The total printing pressure is Pkg, the distance between the bearing and the strain gauge 24 shown in FIG. 1 is 1, and the strain at that point is ε.
And the Young's modulus of the shaft material is E and the bending stress is σ
If kg / mm ² , σ = E · ε, the bearings are arranged symmetrically about the center. Therefore, if the section coefficient of the strain gauge is Z, then σ = M / Z = P / 2 × l × 1 / Z Printing pressure Becomes

Converting the amount of strain into printing pressure by the above, it is approximately 630
It was found to be 1150 kg / cm. That is, if the printing pressure is changed and the amount of strain at that time is measured, the relationship with the strain printing pressure of the frame can be known. Therefore, conversely, if the distortion of the frame is known, the total printing pressure P can be known and the printing pressure can be displayed. It has been confirmed by experiments that the relationship between the frame strain and the printing pressure preferably has linearity (linearity), and that it is linear on the compression side in the printing pressure direction.

Also, the second moment of area ID at the center of the entire length of the intaglio cylinder 6
Is sufficiently larger than the geometrical moment of inertia Id of the end shaft 6b and ID> Id. Therefore, this can be confirmed by actual measurement by pressurizing this with a load cell and measuring the applied pressure and strain ε ₂₄ .

In addition, in the present embodiment, an example in which the strain gauge is provided only on the operation side frame 3 is shown.
It can also be attached to the front and back surfaces of the driving side frame 2 as shown by 6. That is, this strain gauge 25,
Strains of 26 are ε ₂₅ and ε ₂₆ , and the strains ε ₂₀ and ε are
₂₁ together with ε ₂₀ + ε ₂₁ , ε ₂₅ + ε ₂₆ , ε ₂₀ + ε ₂₁ + ε
_{If 25} + ε ₂₆ is output and these three types of strain can be switched and recorded, the printing pressure unevenness in the longitudinal direction of the cylinder can be known by comparing ε ₂₀ + ε ₂₁ and ε ₂₅ + ε _26. . In addition, in each of the above embodiments, the present invention is applied to the intaglio cylinder 6
Although the example is shown on the side, it goes without saying that it may be provided on the impression cylinder 9 side to which the same printing pressure is applied.

[Effect of device]

As is apparent from the above description, according to the present invention, in the rotary printing press, the strain gauge is attached to the frame surface adjacent to the bearing fitted to the frame by pivotally supporting the end shaft of the cylinder to which the printing pressure is applied. However, by detecting the compressive strain due to the printing pressure and displaying the magnitude of the printing pressure, if the appropriate printing pressure is grasped numerically, it is possible to replace the paper when the packing of the impression cylinder is replaced or the packing is worn. The printing pressure can be easily adjusted when the thickness is changed, and the quality of the printed matter is stable. Further, it is possible to prevent accidents such as wear and damage of the bearing portion and breakage of the body end shaft due to excessive printing pressure, and durability and safety are improved.

[Brief description of drawings]

1 to 5 show an embodiment of a printing pressure display device of a rotary printing machine according to the present invention. FIG. 1 is a schematic front view of an intaglio printing machine which carries out this, and FIG. A cylinder and a side view, FIG. 3 is a block diagram, FIG. 4 is a relationship diagram of a strain amount and time during a printing operation, and FIG. 5 is a cylinder arrangement diagram of an intaglio printing machine embodying the present invention. 1 ... Recessed cylinder printer, 2, 3 ... Frame, 4, 5 ... Bearing, 6
... Intaglio cylinder, 7, 8 ... Eccentric bearing, 9 ... Impression cylinder, 20, 21,
24, 25, 26 ... Strain gauge, 22 ... Dynamic strain measuring device, 23 ... Recording device.

Claims (1)

[Scope of utility model registration request] 1. A rotary printing machine, wherein a strain gauge for detecting compressive strain is attached to a frame surface in the vicinity of a bearing fitted to the frame by rotatably supporting an end shaft of a cylinder to which printing pressure is applied. Printing pressure display device.