JPH08108393A - Disc spring of round teeth slitter and its cutting method - Google Patents

Abstract

PURPOSE: To lengthen the service life of both upper and lower edges by adjusting contact pressure between the upper edges and the lower edges, and cut a sheet with high accuracy by obtaining proper contact pressure, by improving a defect of a round teeth slitter, and working grooves only in an outer peripheral part of disc springs. CONSTITUTION: In a round teeth slitter composed of plural sets of rotary upper edges and lower edges, a large number of grooves 3 are arranged toward the center from only an outer peripheral part of respective disc springs 2, and contact pressure between the respective upper edges and the respective lower edges is properly adjusted by the respective disc springs 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a round blade slitter for cutting a long sheet such as a film, a magnetic sheet, a paper or a metal foil into a predetermined number of strips.

[0002]

2. Description of the Related Art Generally, a round blade slitter of this type includes an upper blade (first knife) and a lower blade (second knife). Hard materials such as cemented carbide and ceramics are used for the upper and lower blades. A plurality of upper blades are fixed to the rotatable first shaft at regular intervals in the axial direction. The plurality of lower blades are rotatable and are fixed to a second shaft positioned so that the respective cutting edge portions and the plurality of upper blades are in contact with each other at an interval corresponding to the interval between the upper blades. .

For example, when cutting a magnetic sheet, the magnetic sheet is inserted between a rotating upper blade and a lower blade, and the upper blade and the lower blade are sequentially contacted with each other at their contact points. The magnetic sheet is cut to produce a slender audio tape or video tape.

In FIG. 7, the first shaft S ₁ and the second shaft S ₂ of the round blade slitter are provided so as to be rotatable in parallel with each other and relatively movable in the axial direction. The upper blade holder 1 is fixed to the first shaft S ₁ while being divided in the axial direction, and the upper blade K1 is attached to the step portion 1a of each upper blade holder 1. The upper blade K1 has a wall thickness of 0.1 to 1.0 mm, and is arranged between one end surface of the flange portion 1b of the adjacent upper blade holder 1 and the step portion 1a,
The disc spring 2 having elasticity is fixed to the flange portion 1b of the adjacent upper blade holder 1 in a pressed state.

On the other hand, the lower blade K2 has a stepped shape having a large diameter portion K2a and a small diameter portion K2c, and the end surface of the large diameter portion K2a is a cutting blade portion K2b.

The upper blade K1 is pressed against the end surface of the flange portion 1b of the upper blade holder 1 by the disc spring 2, and the upper blade K1 is further pressed.
The lower blade K2 and the lower blade K2 are rotated by bringing the cutting edge portion into close contact with each other to cut the original sheet.

The structure of the conventional disc spring 2 is shown in FIG. 10 (the groove and the drill hole are not provided), and the disc spring 2 shown in FIG. 11 is provided with a large number of drill holes 6 in the peripheral portion thereof. And a large number of grooves 7 in the radial direction on the inner peripheral portion of the disc spring 2 shown in FIG.
In addition, a plurality of grooves 3 are also provided in the radial direction on the outer peripheral portion, and the grooves 7 and 3 are arranged alternately.

[0008]

[Problems to be Solved by the Invention]

(1) In the round-blade slitter, in order for all the tapes to be satisfactorily cut, it is necessary that all the upper blades and the lower blades are in contact with each other with a uniform pressure. The tape cut by the upper blade and the lower blade that are not in contact with each other has a badly torn cut end, and a tape having a sharp cut surface cannot be obtained. In a multi-threaded round blade slitter, variations in contact pressure affect the quality of the tape. In order to improve productivity, the raw tape has a tendency to become wider year by year, and as the number of strips is increased, the contact pressure between the upper blade and the lower blade becomes different. The factors can be listed as follows.

A. Side run-out of the upper or lower blade alone B. Variation in thickness, parallelism or flatness of the lower blade or upper blade holder C. Difference in cumulative thickness dimension of lower blade or upper blade holder (product of unit thickness dimension and number of sheets) Assemble upper blade, upper blade holder, disc spring and lower blade into each shaft, and move upward toward blade surface of lower blade. When any one of the above factors A, B or C is present when the blade axis is moved to bring the upper blade and the lower blade into contact with each other, the upper blade and the lower blade may or may not come into contact with each other. Occurs. To bring all the upper and lower blades into contact, it is necessary to move the shaft. Therefore, the pushing amount (the amount moved further after the contact between the upper blade and the lower blade) is different between the upper blade and the lower blade that came into contact first, and the upper blade and the lower blade that came into contact last, There is a difference in the contact pressure between the blade and the lower blade.

Particularly, the upper blade and the lower blade, which have a high contact pressure, are subject to wear or chipping (spillage) during cutting, and even if the sharpness of most of the upper blade and the lower blade is good, If there is an upper blade and a lower blade that have poor sharpness in part, the cutting must be stopped, and the cutting life of the slitter knife will be shortened.

(2) Generally, when a slitter knife is worn, the outer peripheral surface is ground to remove the worn portion and is reused. When polishing is repeated many times, the outer diameter of the upper blade is
It gradually shrinks like. If the same disc spring is used, the contact pressure between the upper and lower blades will be stronger in response to the smaller outer diameter of the upper blade, and the tape will be applied with a stronger contact pressure than before re-polishing. Disconnect. Therefore, the cutting edge of the upper blade is significantly worn or chipping occurs, and the life of the slitter knife is shortened.

(3) A high-quality magnetic tape having a hard magnetic layer and a hard base film is required to be cut with an appropriate contact pressure between the upper blade and the lower blade, which is suitable for the upper blade. It cannot be sharply cut by the conventional means for pressing the disc with a disc spring.

(4) A schematic view of a conventional disc spring is shown in FIG. The disc spring is characterized by a small volume, particularly a small dimension in the pushing direction, and a large spring capacity. Hardened steel is generally used as the material of the disc spring, and there are variations in hardening strain and hardness. In order to reduce the contact pressure difference between the upper and lower blades of the round blade slitter, the height H dimension and the thickness t dimension in FIG. 9 were considered important and the processing method and the shape of the disc spring were changed. , Due to unevenness and hardness variation due to quenching distortion in the quenching process of disc springs,
Since the variation in H and t dimensions cannot be 0.005 mm or less and it is difficult to maintain the accuracy due to changes over time, reduce the contact pressure difference between the upper and lower blades of the round blade slitter. Was difficult.

Therefore, the present invention improves the drawbacks of the conventional round blade slitter and controls the contact pressure between the upper blade and the lower blade by forming a groove only on the outer peripheral portion of the disc spring, thereby allowing the slitter to move. The purpose is to extend the life of the knife (upper blade and lower blade) and obtain an appropriate contact pressure to cut the sheet with high accuracy.

[0015]

[Means for Solving the Problems] As a drawback of the multi-strand round blade slitter, the greater the number of knives,
Due to the precision of the knife, there is a difference in cumulative thickness between the lower blade and the upper blade holder after assembly. Therefore, the contact pressure between the upper blade and the lower blade is different for each portion, and the knife damage degree is different for each portion, which is a factor of shortening the cutting life.

In order to solve the above-mentioned problems, the present invention adjusts the pushing amount in a range of 0.05 to 0.30 mm in a round blade slitter composed of a plurality of rotating upper blades and lower blades, A means for cutting the sheet by adjusting the contact pressure between each upper blade and each lower blade in the range of 150 to 350 gf by each disc spring provided with a large number of grooves from the outer peripheral portion only toward the center is adopted. .

[0017]

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

First, an embodiment of the present invention is shown in FIG. 1.0m width evenly distributed on the outer periphery of the disc spring 2 with n = 36 places
The groove 3 having a depth of m and a depth of 1.0 mm was processed. The outer diameter of the disc spring is 80 mm, the inner diameter is 60 mm, the thickness is 0.4 mm, and the height is 1.
It was set to 61 mm.

FIG. 2 shows a method of measuring the relationship between the pressing amount (the amount of further movement after the contact between the upper and lower blades) and the contact pressure. The blade holder 1 on which is fixed to the first shaft S ₁ equipped with the upper blade K1 and disc spring 2, on the disc spring 2 blade K
When 1 is brought into contact with the lower blade (the load cell 4 is a virtual lower blade in FIG. 2) and the upper blade K1 is moved in the lower blade direction P, the contact pressure increases. The moving amount of the upper blade K1 at that time was measured with the dial gauge 5, and the measured value was taken as the pushing amount, and the contact pressure at that time was measured with the load cell 4 and shown in the graph of FIG.

In FIG. 3, the conventional disc spring 2 having no groove shown in FIG. 10 is compared with the disc spring 2 of one embodiment of the present invention to have an outer diameter, an inner diameter, a thickness t and a height H. The graph at the time of experimenting under the same conditions as the blade K1, the upper blade holder 1, and the lower blade is shown.

When an appropriate contact pressure of 350 gf and a difference in the pushing amount of 40 μm are required, the point on the graph of the contact pressure of 350 gf is A, and the pushing amount is 20 μ to the left and right from A respectively.
m, and the intersections with the graph are A ₁ and A ₂ , respectively, A ₁ and A ₂ are moved at right angles to the vertical axis, and the intersections with the vertical axis are A ₃ and A ₄ , A ₃ and A ₄ Is the difference in contact pressure.

Then, in the conventional disc spring, the difference in contact pressure is 140 gf, whereas in the disc spring of one embodiment of the present invention, the difference in contact pressure is 35 gf.
Becomes

Further, the number of slitter knives is increased,
Even if the difference in the pushing amount increases to 60 μm, the difference in contact pressure is as small as 55 gf in the disc spring of the embodiment of the present invention. It is desirable that the disc spring has a small difference in contact pressure even if the pushing amount increases.

Next, FIG. 4 shows a graph when only the groove depth of the disc spring 2 of one embodiment of the present invention is changed to 2.0 mm, and a graph when it is changed to 3.0 mm. , Respectively.

When an appropriate contact pressure of 250 gf and a difference of pushing amounts of 40 μm are required, the conventional disc spring has a contact pressure difference of 170 gf, whereas the disc springs of one embodiment of the present invention have: Contact pressure difference is 60g each
f, 45 gf, 35 gf, which are significantly reduced. Further, even if the pushing amount increases to 60 μm, the difference in contact pressure between the disc springs is 50 gf.

FIG. 5 shows a conventional disc spring 2 (FIG. 10),
Conventional disc spring 2 (FIG. 11, where the number of drill holes 6 is n =
18, drill hole diameter 5mm), conventional disc spring 2 (Fig. 1
2, however, the number of grooves 3, 7 n = 18, groove width 1.0 m
m, groove depth 1.0 mm), disc spring 2 (FIG. 1) of one embodiment of the present invention, and only groove depth of one embodiment of the present invention is 2.0.
3 shows respective graphs of a disc spring (FIG. 1) changed to mm and a disc spring (FIG. 1) in which only the groove depth of one embodiment of the present invention is changed to 3.0 mm. The dimensions of the disc spring are 80 mm in outer diameter, 60 mm in inner diameter, t = 0.4 mm in thickness, and H = 1.61 m in height.
m.

As a result, when the pushing amount increases, the contact pressure also increases. Comparison of increase rates >>
>>>, the conventional disc spring (Fig. 10) was the largest, and the disc spring in which the groove depth was changed to 3.0 mm in the embodiment of the present invention was the smallest.

On the other hand, a cutting test of the magnetic sheet was conducted using the above-mentioned disc spring. The cutting test was carried out by using a cutting device of 50 blades each for the upper blade / set, and the same lower blade for the upper blade was subjected to outer peripheral polishing before use. The thickness of the magnetic sheet to be cut is 19μ
There are 2 types, m and 8 μm, and the cutting speed is 25
It was set to 0 m / min.

When chipping occurs on the upper blade or the lower blade and the cut tape appears to be damaged, or when the tape is torn due to a weak contact pressure, the cutting is stopped, and the above-mentioned time is set to the plate. The life was determined to be when the spring was used, and the cutting distances were compared and measured. Further, when the predetermined cutting distance was reached, the wear state of the tip of the upper blade was checked.

The contact pressure between the upper blade and the lower blade is 350 gf when the VTR tape thickness is 19 μm, and the high-grade tape thickness is 8 μm.
For m, a cutting test was conducted with 200 gf, and the results are shown in Table 1 below.

[0031]

[Table 1] ○: Good up to 700,000 m, abrasion of the upper blade is 3 μm or less △: Good up to 500,000 m ×: Abnormality on the tape without reaching 500,000 m Thickness 19 μm All the disc springs cut the tape to 700,000 m. However, when the wear state of the tip of the upper blade was observed, it was found that the wear was 2.5 μm,
The wear was 1.0 to 1.5 μm. (Refer to FIG. 6) Further, in cutting the tape having a thickness of 8 μm, 700,000 m was cleared when the disc spring of was used.
When the disc spring of No. 1 was used, chipping occurred before reaching 700,000 m, and the tape was damaged. The upper blade had a wear condition of 2.0 to 3.0 μm.

As described above, good results were obtained even when the tape was thin, that is, when the cutting property was to be deteriorated.

The following items could be confirmed by the experiment of the embodiment of the present invention.

(1) Shape and size of disc spring (thickness, height,
Even if the outer diameter and the inner diameter are the same, it was difficult to make the spring strength uniform due to the occurrence of distortion in the quenching process, but by processing the slit groove on the outer periphery of the disc spring,
Quenching distortion was eliminated and it became possible to control spring strength uniformly.

(2) In order to slit the magnetic tape with high accuracy, it is necessary to change the contact pressure of the knife depending on the tape thickness and the hardness of the base film and the magnetic layer. The conventional cone-shaped contact pressure is usually 600 gf, which is a limit that can be reduced by 400 gf even by adjusting the components, and does not satisfy the recent demand level for high-precision cutting. By machining slit grooves on the outer circumference of the disc spring in 0.1 mm increments so that the conventional disc spring has an appropriate constant contact pressure, the existing disc spring can be used as it is for high-quality products, resulting in cost reduction and manufacturing. The number of days was shortened.

(3) When a wide original sheet is cut, by using a disc spring having slit grooves, even if the pushing amount is increased, the contact between the upper and lower blades is increased. The difference in pressure is small, and chipping of the upper blade, which has been caused by the large difference in contact pressure as in the past, is eliminated, and the life of the upper blade and the lower blade is greatly extended.

[0037]

The present invention has the following effects due to the above-mentioned configuration.

(1) By processing the slit groove only on the outer peripheral portion of the conventional disc spring, the contact pressure between the upper blade and the lower blade is reduced to 1
It can be held constant at 50-350 gf, and can always cut with the appropriate contact pressure between the upper and lower blades, depending on the requirement for multiple strips and the type of tape, film, etc. to be cut. Therefore, the life of the slitter knife is extended.

(2) Even if the dimension of the worn slitter knife after re-polishing changes, the contact pressure between the upper blade and the lower blade can be kept constant, and the life of the slitter knife is extended.

(3) The pushing amount is 0.05 to 0.30 m
Adjust the contact pressure between the upper and lower blades to be 15 in the range of m.
By obtaining an appropriate value of 0 to 350 gf, it is possible to cut the sheet with high accuracy.

[Brief description of drawings]

FIG. 1 shows a disc spring of an embodiment of the present invention, (a) is a front view and (b) is a side view.

FIG. 2 is a schematic diagram of a method for measuring the pressing amount and the contact pressure when the disc spring of the embodiment of the present invention is used.

FIG. 3 is a graph showing a pressing amount and a contact pressure when a disc spring according to an embodiment of the present invention and a conventional disc spring (having neither a groove nor a drill hole) are used.

FIG. 4 is a graph of the pressing amount and the contact pressure when a disc spring of one embodiment of the present invention (three kinds of groove depths) and a conventional disc spring (without a groove and a drill hole) are used. Is.

FIG. 5 is a graph of the pressing amount and the contact pressure when using a disc spring of one embodiment of the present invention (three kinds of groove depths) and three conventional disc springs.

FIG. 6 is a diagram showing a worn state of the upper blade when the disc spring of the embodiment of the present invention is used.

FIG. 7 is a cross-sectional view of a conventional round blade slitter.

FIG. 8 shows the state of wear of the upper blade of a conventional round blade slitter and the dimensions after re-polishing, where (a) is a front view and (b) is a side view.
(C) is an enlarged cross-sectional view of a main part in (b).

FIG. 9 is a schematic sectional view of a conventional disc spring.

FIG. 10 Conventional disc spring (without a groove and a drill hole)
Is a front view and (b) is a side view.

FIG. 11 shows a conventional disc spring having a drill hole,
(A) is a front view and (b) is a side view.

FIG. 12 shows a conventional disc spring having grooves in the outer peripheral portion and the inner peripheral portion, (a) is a front view and (b) is a side view.

[Explanation of symbols]

1 Upper blade holder 1a Step portion 1b Flange portion 2 Disc spring 3 Groove 4 Load cell 5 Dial gauge 6 Drill hole 7 Groove K1 Upper blade K2 Lower blade K2a Large diameter portion K2b Cutting blade portion K2c Small diameter portion S ₁ First shaft S ₂ Second shaft

Claims (2)

[Claims] 1. A round-blade slitter comprising a plurality of rotating upper blades and lower blades, wherein a large number of grooves are provided from the outer peripheral portion of each disc spring toward the center, and each disc spring forms an upper blade. A disc spring for a round blade slitter, which is characterized by adjusting the contact pressure between the lower blade and each lower blade. 2. A round blade slitter composed of a plurality of sets of rotating upper blades and lower blades, with a pushing amount of 0.05.
Adjust the contact pressure between each upper blade and each lower blade in the range of 150 to 350 gf by each disc spring provided with a large number of grooves from only the outer peripheral portion toward the center. A method for cutting a round blade slitter, which comprises cutting a sheet.