JPH09323287A - Cutting method of corrugated cardboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To finish a cutting surface of a cut work neatly without crushing it, insofar as possible and to make a cutter so as to dispense with its being worn out, at the time of cutting work on corrugated cardboard or the like. SOLUTION: A thin rotary cutter 1 attached with a serrated tooth form making a line connecting a cutting edge turn to a straight line and a receiving roll 2 are set up so as to make a part of the cutter 1 enter in a groove of this receiving roll 2, rotating the cutter, and a cut work is traveled in an interval between the cutter 1 and the roll 2 and thereby this cut work is cut off, and at the time, an S value or the ratio of a travel speed of the cut work and a peripheral velocity of the rotary cutter is made larger than r/(r-αd-e), and further an upper limit is set to the range of 1.2r/(r-αd-e) and it is adjusted so as to an approximate value to r/(r-αd-e) insofar as possible. Where, (r) is a radius of the ritary cutter, αd is apparent thickness in time of cutting the cut work, (e) is depth of engagement between the cutter and the receiving roll, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting method for cutting a sheet-shaped object to be cut such as corrugated cardboard.

[0002]

2. Description of the Related Art One of the methods for cutting corrugated board is slit cutting as a method for cutting the corrugated board parallel to the traveling direction of the corrugated board. As a concrete content, a method which is generally used is as follows.
A so-called shear cut method, in which a plurality of rotating circular knives 5 and 6 are arranged so that their tips are slid on each other, and an object to be cut 3 such as a corrugated board is cut while running, b).
Instead of slicing cut, one sharp knife is positioned so that the tip faces the groove of the receiving roll with a thin groove, and the knife is rotated at high speed to cut it, just with "Sashimi knife" There are a method of cutting in a state where it is cut by pull-cutting, a method of c) a rotating saw-like thing and a cutting at high speed rotation.

[0003]

In the method a), two knives are slid on each other and cut. Therefore, there is no problem in cutting a thin object, but when it is thick, the cutting surface is crushed. There is a problem that it is inevitable to cause such a phenomenon. In order to solve it, the cutting edge has an acute angle,
If you try to reduce the crushing phenomenon, it is a mechanism that slides the two blade edges together, so if you do not try a little, the blade edges will reverse and the phenomenon of what is called an "Isuka's beak" will occur. The actual situation is that it will be damaged and it will not be possible to form a sharply cutting edge. When slit-cutting a thick one such as a three-layer corrugated board having a thickness of 15 mm or more, which is different from a general corrugated board sheet, cutting with such a shear cut method is a crushing phenomenon of a cutting part. Is severe, and the cut surface is torn, and there are many problems in terms of the quality of the cut surface.

In the method b), the cut surface is cut very sharply, and ideal cutting is achieved without the crushing phenomenon. On the other hand, the blade is sharply cut at an acute angle and rotated at high speed. Therefore, it cannot be licked that the cutting edge becomes worn and the sharpness deteriorates in a short time. Therefore, the cutting device is required to have a polishing mechanism or the like at a position where it does not interfere with the cutting of the upper part of the blade, and to provide means for automatically and sometimes sharpening the sharpness.

Further, in the above method c), since the blade has a saw-like shape and rotates at a high speed, the blade passes through the same place of the object to be cut many times, resulting in a large amount of sawdust peculiar to the saw and abrasion. Since it has a serrated cutting edge, it has many problems such as the inability to use the above-mentioned polishing mechanism.

The present invention has been made in view of the above problems of the prior art, and the purpose thereof is to make the cut surface of an object to be cut clean and finish it as clean as possible.
Moreover, it is intended to minimize the wear of the blade. What must be particularly understood about the present invention is that if the object to be cut has a thickness of 10 mm or more, such as three-layer corrugated board, or 15 mm or more, it cannot be cut neatly with a general shear-cut type slitter, and A method must be provided that not only cuts thick ones, but also cuts thin and thick ones irrespective of thickness, and must also reduce the wear of the blade. It means that it must be.

[0007]

In order to achieve the above object, in the corrugated board cutting method of the present invention, a thin rotary blade having a saw-like blade shape and a receiving roll provided with a groove having an appropriate width are provided. The part of the blade of the blade is arranged so as to enter the groove of the receiving roll and the blade is rotated, and the object to be cut is cut by running the object to be cut between the blade and the receiving roll, At this time, regarding the relative speed between the traveling speed of the object to be cut and the peripheral speed of the rotary blade, optimum conditions are always given to variable conditions such as the diameter of the rotary blade and the thickness of the object to be cut. As the optimum conditions, the ratio of the traveling speed of the object to be cut and the peripheral speed of the rotary knife is S, the radius of the rotary knife is r, the thickness of the object is d, the compressibility of the object is α, and the knife When the engagement depth with the receiving roll is e, the S value is r /
In order not to be less than (r-αd-e), r / (r-
It is desirable to adjust the value to be as close as possible to αd-e). However, as a practical matter, the radius r of the rotary blade, the thickness d of the object to be cut, the compressibility α of the object to be cut, and the engagement depth e of the knife with the receiving roll constantly change. That is, the radius r of the rotary blade slightly changes due to the wear of the blade, the thickness d of the cut object always fluctuates within a certain range, and the compressibility α of the cut object depends on the material of the cut object. It has a feature that it changes within a certain range depending on the situation, such as change, and is not constant. Therefore, the S value, which is the ratio of the running speed of the object to be cut and the peripheral speed of the rotary blade, is constantly changed depending on the situation, but in practice, it is very difficult. On the other hand, as a result of examining the effect of cutting and the change of wear of the cutting device and the generation of sawdust within a range of the minimum value and the maximum value of the actual conditions by slightly changing the S value, it is found that there is no great difference in the change. found. Therefore, the inventors further conducted a test and, for safety, worked sufficiently even in the range where the upper limit of the maximum value of the actual condition range was increased by 20%, whereby the cutting condition of the cutting object and the cutting device It was confirmed that there was almost no difference in wear and generation of sawdust. That is, in order to accurately respond to constantly changing conditions, S
It was found that it is sufficient to operate by fixing the S value within the safe range so as to change the value. Therefore, in the present invention, the S value, which is the ratio of the running speed of the object to be cut and the peripheral speed of the rotary blade, is set to r / (r-αd-e) <S ≦ 1.2 r / (r-αd-e). It is to be adjusted.

[0008]

In the cutting method for corrugated cardboard or the like of the present invention having the above-described structure, basically, the cutting is performed by using a knife as in the above method b). The cutting is done slowly. In addition, the traveling speed of the object to be cut is too fast with respect to the peripheral speed of the rotary blade, and the phenomenon that the object to be struck against the blade while the object to be cut does not occur.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. In FIG. 1, 1 is a rotary blade, 2 is a receiving roll, 3 is an object to be cut, and a three-layer corrugated cardboard is shown as the object to be cut 3 in the figure. The rotary knife 1 is, as shown in FIG.
A circular knife is formed into a sawtooth shape in which the line connecting the cutting edges 11 is a straight line, and is formed into a round saw shape without a set. Further, the receiving roll 2 has a groove 21 having an appropriate width on the peripheral surface. The rotary blade 1 and the receiving roll 2 are respectively the rotary shafts 12 and 22.
The blade 11 of the blade 1 is arranged so that part of the blade 11 of the blade 1 enters the groove 21 of the receiving roll 2. The object to be cut 3 is rotated by a suitable feeding device (not shown).
And the receiving roll 2 are fed and run. The rotary shafts 12 and 22 of the rotary blade 1 and the receiving roll 2 are driven by a driving device (not shown) to rotate in the traveling direction of the object 3. It should be noted that the rotation shaft 22 of the receiving roll 2 may be rotationally free without being intentionally driven to rotate.

Thus, the object to be cut 3 is cut by running between the rotary blade 1 and the receiving roll 2. In the present invention, however, the running speed and rotation of the object to be cut 3 at this time. The S value, which is the ratio of the peripheral speed of the blade 1, is optimally adjusted. The determination of the S value will be described below.

Assuming that the radius of the rotary cutting tool 1 is r, the thickness of the cutting object 3 is d, and the engagement depth of the cutting tool 1 with the receiving roll 2 is e, OP = r, AB = d, BC = in FIG. It becomes e. The material to be cut 3 has different hardness depending on the material,
The softer the material, the more deformed it will be when it is pressed by the tip of the blade 1 during cutting. The degree of compression is α
When expressed by, the apparent thickness at the time of cutting is αd. Hence AB
= Αd.

Now, an angle formed by a line connecting points P and O and a line connecting points O and C when one point of the tip of the rotary blade 1 enters the object 3 at point P = θo Then, the angle formed by the line connecting points Pi and O when rotating from point P to Pi and the line connecting points O and C is set to θi, and at the point Q, the tip of the rotary cutting tool 1 The peripheral speed of the tip of the rotary blade 1 is V, where the angle formed by the line connecting the points Q and O and the line connecting the points O and C when one point leaves the object 3 again is set to V.
If the traveling speed of the object to be cut 3 is v, the relative positional relationship with the object to be cut 3 is defined as the position where one of the tips of the blade 1 enters the object to be cut 3 at point P and moves. Let y be the origin, P be the origin, and θ be the parameter, and the traveling direction of the object to be cut 3 is x.
If expressed by a coordinate system in which the axis and the direction perpendicular to the axis are the y-axis, that is, x = r (θ / S-sin θ) -K ... ...... Y = (r-αd-e) -rcos θ ...... = V / v K = a conversion factor with the point P as the origin.

If this is shown in a concrete example, Table 1 and a graph thereof are as shown in FIG. That is, as changing conditions, r: radius of the rotary cutting tool 1 d: thickness of the cutting target 3 e: depth of engagement between the rotary cutting tool 1 and the receiving roll 2 α: degree of compression of the cutting target 3 The values of x and y are obtained from the formula by giving specific numerical values. However, the value is S = V
Depending on how to determine the value of / v, the relational value of x and y changes as shown in Table 1 and FIG.

[0014]

[Table 1]

Table 1 is a table showing the relationship between the relative position of the tip of the rotary blade 1 and the object 3 to be cut according to the values of S in (1) to (4) shown in the table. (1) is a case where the peripheral speed V of the tip of the rotary blade 1 and the traveling speed of the object 3 are equal at S = 1. (2) is a case where the tip of the rotary blade 1 enters from the P point and the cut object 3 moves from the P point to the traveling position of the Q point while exiting at the Q point. (3) is a case where the speed at the tip of the rotary blade 1 at the point P in the traveling direction of the workpiece 3 is equal to the traveling speed of the workpiece 3. (4) is a case where S = ∞. That is, this is a case where the rotary blade 1 is cut at high speed. Among the values of S for each of these, S = 1 / cos θo in (3)
In the case of a smaller S value, a negative value appears in the value of x. That is, during cutting, during the movement of the tip of the rotary cutting tool in the x-axis direction, a large point of time when the object to be cut 3 travels appears, which causes a phenomenon of hitting the object 1 and damaging the tool 1 or running the object 3 to be cut. It will be a situation that will disturb you. When (4) is larger than the S value of (3), there is no hindrance to the cutting traveling, but since the peripheral speed of the rotary blade 1 is fast, the blade 1 wears quickly, and because it is a saw blade, so-called sawdust Is more likely to occur, and there are more problems such as worsening the cutting environment. From Table 1 and FIG. 5, the most desirable S value is the condition (3), that is, S = 1 / cos θo =
It is understood that it is desirable that the value is larger than the value of r / (r-αd-e) and is as close as possible. Therefore, in the present invention, when the corrugated cardboard or the like is cut, the traveling speed of the object to be cut 3 and the rotary blade 1
The S value, which is the ratio of the peripheral velocities of S, is adjusted so as to be larger than S = r / (r-αd-e) and as close as possible to r / (r-αd-e). The upper limit is r / (r-αd-
It is S = 1.2 r / (r-αd-e), which is a 20% increase of e). The upper limit of the S value is set to be 20% higher than r / (r-αd-e) because the cutting condition of the object to be cut is within this range,
This is because the inventors confirmed by tests that there was almost no difference in wear of the cutting device and generation of sawdust.

A feature of the method of the present invention is that the optimum S value can be easily calculated with respect to variations in the thickness of the object 3 to be cut and changes in blade conditions such as r and e. The optimum S value for cutting described so far changes variously depending on the diameter of the rotary blade 1, the engagement depth between the rotary blade 1 and the receiving roll 2 and the apparent thickness of the object 3 to be cut. Figure 5
It is expressed by. That is, the optimum S value shows a situation in which only the apparent thickness of the object to be cut 3 changes if the conditions of the rotary blade 1 are determined.

[0017]

[Table 2]

Incidentally, r = 120 mm, d = 15 mm,
When e = 2 and α = 0.8, the optimum value is S = 1.132, and if the peripheral speed of the tip of the cutting tool 1 is set to 1.132 times the traveling speed of the cutting object 3, It will be good. That is, the peripheral speed should be 13.2% faster than the running speed.
Thus, increasing the peripheral speed of the cutting tool 1 by 13.2% with respect to the traveling speed of the object to be cut 3 makes the traveling speed 100% per minute.
In the case of m, the relative speed is 13.2 m / min, and the cutting is performed at a very slow speed, and the blade 1 does not wear unnecessarily.

Since the cutting is carried out under such a condition that the relative speed is small, the rotary cutting tool 1 is a saw-like blade as shown in FIG. 3 in the present invention so that the cutting tool 1 can easily bite into the cutting object 3. Is characterized by.

[0020]

The present invention is configured as described above, and has the following effects. (1). Basically, since the object to be cut is cut with a knife, the cut surface is cut extremely sharply, and there is no crushing phenomenon, which is ideal cutting. (2). Since the relative speed between the traveling speed of the object to be cut and the peripheral speed of the rotary cutting tool is reduced to a necessary minimum and cutting is performed at a very slow speed, the cutting tool is hardly worn. (3). Since the rotary blade is provided with a saw-tooth blade shape in which the lines connecting the blade edges are straight, the biting of the blade with respect to the object to be cut is good despite the fact that the rotary blade is cut under the condition that the relative speed is small as described above. (4). Radius of rotary blade 1: r, thickness of cut object 3:
d, the depth of meshing of the cutting tool 1 with the receiving roll 2: e, which is the ratio of the traveling speed of the object to be cut to the peripheral speed of the rotating tool S
Since the value is set to be larger than r / (r-αd-e), there is a possibility that the traveling speed of the object to be cut is too fast with respect to the peripheral speed of the rotary blade, and the object may hit the blade. In addition, there is no possibility of causing damage to the cutting tool or obstructing the traveling of the cut object.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method of cutting a corrugated board or the like of the present invention.

FIG. 2 is an explanatory view explaining the principle of the method of the present invention.

3A and 3B are explanatory views of a rotary blade, where FIG. 3A is a front view and FIG.
Is rotatably illustrated in the enlarged view of part A of FIG.

FIG. 4 is a graph showing a locus of cutting for each S value, which is a ratio of the traveling speed of the object to be cut and the peripheral speed of the rotary blade.

FIG. 5 shows the diameter of the rotary blade and the apparent thickness of the cut object,
The graph which shows the relationship of S value.

FIG. 6 is a perspective view showing an example of a conventional method for cutting a corrugated board or the like.

[Explanation of symbols]

1: Rotary blade 2: Receiving roll 3: Object to be cut 11: Blade edge 21: Groove

Claims (1)

[Claims] 1. A thin rotary blade having a circular knife and a saw-like blade shape in which the line connecting the blade edges is straight, and a receiving roll provided with a groove having an appropriate width, wherein a part of the blade of the blade receives the blade. Cut the object by placing it so that it fits in the groove of the roll and rotating the tool between the tool and the receiving roll to cut the object. At this time, run speed and rotation of the object. A method for cutting corrugated board or the like, characterized in that the S value, which is the ratio of the peripheral speed of the cutting tool, is adjusted so that r / (r-αd-e) <S ≦ 1.2 r / (r-αd-e). However, r: radius of rotary blade d: thickness of object to be cut α: compressibility of object to be cut e: depth of engagement with rotary tool receiving roll