JPS6236840B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cutting a strip-like soft material such as cardboard.

Conventionally, this type of device is called a slitter, and has quite thick rotary blades arranged in a staggered manner on rotating shafts arranged above and below, and the rotating shafts are rotated at a speed slightly faster than the transport speed of the material to be cut. , a method was adopted in which the material to be cut was sandwiched between both blades and sheared.

For this reason, when the material to be cut is a composite paper such as corrugated cardboard with a liner paper on the surface and a corrugated core paper on the inside, the area around the cut part is deformed due to compression before the cutter starts cutting. Since the shearing is done with a thick knife, the cut end is crushed, resulting in what is commonly called crow's feet.Also, when adjusting the gap between the upper and lower cutters, strict adjustment of the cutting edge is required to obtain the best possible cut surface. Furthermore, each time the width of the paper to be cut was changed, it was necessary to move and adjust the double-edged tools on the vertical rotation axis, but this alignment required a great deal of effort and effort.
There were drawbacks that required time and skill.

Therefore, in order to improve these shortcomings, 1.
Cutting devices using two rotary blades, such as circular or serrated blades, have been proposed in the past, but since these rely on shearing in the same way as the aforementioned two-blade blade, they It is desirable to provide a receiving member for the material to be cut, but this also has the drawback that the cut surface is likely to be crushed, deformed, and scratched by the receiving member as described above.

Furthermore, if the rotation of the rotary blade is accelerated, damage and deformation of the cut surface will be improved to some extent, but on the other hand, the blade edge will overheat and become soft due to heat generated by friction between the cut material or receiving material and the blade. However, this method not only deteriorates the sharpness of the blade but also accelerates its wear, and the receiving material also suffers from wear and other damage due to contact with the blade and the material to be cut.

Furthermore, in the case of low-speed rotation with a single blade, the material to be cut is pushed through between it and the receiving material, so the load acting on the blade is large, and the thickness of the blade must therefore be increased. Therefore, the angle of the cutting edge becomes larger, and the force that pushes the cut surface of the material to be cut apart during cutting increases, resulting in an increase in the rotational power of the cutting tool.
There were disadvantages such as crushing of the cut end and increased frictional heat. Therefore, it is better to make the blade as thin as possible, but in the case of a thin blade, the lateral rigidity of the cutting edge will be weakened, causing waving of the cutting edge during cutting, which will not only cause defects in the cutting surface, but also cause damage to the blade itself, overheating, etc. There was a risk of causing an accident, so there were restrictions on the thickness of the blade.

The present invention was proposed to eliminate the various drawbacks of the conventional devices, and its gist is as follows:
A device having a disc-shaped thin blade whose cutting edge is longer than the thickness of the material to be cut and has teeth with the tip sharpened into a wedge shape, and the material to be cut is introduced in a direction tangential to the outer circumference of the disc-shaped thin blade, The material to be cut is cut by slightly varying the transport speed of the material to be cut and the circumferential speed of the rotating disc-shaped thin blade.The purpose of this is to cut the material to be cut in the form of a soft strip, especially for corrugated paper slivers. The purpose of the present invention is to provide a suitable cutting method.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the principle of cutting, and the principle of the present invention will be explained with reference to FIG. 1 in comparison with a conventional case. FIG. 1A shows a side view of cutting using a conventionally proposed circular saw blade, B shows a state of cutting using a conventional circular cutter, and C shows cutting according to an embodiment of the present invention. Shows the state when cutting by the device.
In both figures, the material to be cut 1 is transported in a direction approaching the cutter, and after cutting is completed, it moves away from the cutter.

First, in Fig. 1A, the circumferential speed of the circular saw blade is usually several times or more (for example,
Since cutting is performed at a speed ratio of 10 to 20 times), from the state shown in the figure, the cutting blade 2 cuts the cutting part 3 at the same time,
The cutting blade 2a cuts the end cut surface of the material 1 to be cut. Further, in FIG. 1B, the circular cutter 4 rotates and cuts the cutting portion 5 of the material 1 to be cut according to the feed rate of the material 1 to be cut.

Therefore, conventional cutting devices such as the circular serrated blade shown in Figure 1A and the circular blade shown in Figure 1B have a cutting mechanism that gradually tears apart the side surface of the workpiece 1 as if breaking a cliff. It's summery. However, as shown in FIG. 1C, in the case of the present invention, the cutting blade 6 is longer than the thickness of the material 1 to be cut, and its tip is wedge-shaped and very sharp. In addition, since the circumferential speed of the cutting blade 6 is slightly different from the transport speed of the material to be cut 1, the cutting mechanism is completely different from conventional ones, and the cutting blade 6 pierces the material to be cut one after another, forming a wedge shape. The cutting blade 6 is pushed in, and the cutting parts r ₁ , r ₂ ,
The method is to cut r ₃ while expanding it.

Therefore, when cutting with the cutting blade 2 in Figure 1A,
Since cutting is performed with the side cutting blade 2b, a large cutting load is applied in the circumferential direction, and there are problems such as the required rigidity of the cutting tool as mentioned above. Since this is a method in which the cutting proceeds while cutting, the main cutting load is applied in the radial direction, which is not only advantageous in terms of the rigidity of the blade, but also reduces the cutting load.

The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 2 shows a front view of one embodiment, and FIG. 3 shows a sectional view taken along line XX in FIG. 2. In Figure 2, 7 is a solid or hollow rotating shaft, and 8 is a coaxial shaft 7.
The bearing 8 is fixed to a stand or frame (not shown) at both ends. Further, one end of the rotating shaft 7 is connected to a high-speed rotating prime mover (not shown), for example, a motor equipped with a speed reducer. Further, a fixing jig 9 is fitted onto the rotating shaft 7, and a cutter 10 similarly fitted thereon is fixed with bolts 11.

Next, in FIG. 3, reference numeral 12 denotes a support roll for supporting or transporting the material 1 to be cut. Further, the material to be cut 1 is transported in the direction of the arrow by a transport conveyor or the like (not shown). Here, the transfer speed V' of the transfer conveyor and the circumferential speed V of the cutter 10 need to be set as follows. That is, Z/Z+1VV'<V, or V<V'Z+1/ZV (where Z is the number of blades of the cutter). Note that if V'=V, an uncut portion will be generated at the bottom of the material to be cut 1, so the uncut portion can be eliminated by making V' slower or earlier than V by a maximum of one pitch blade.

Now, in the conventional device described above, a brush roll or a soft material such as urethane is often used as a cradle at the cutting part, but this is necessary because the material to be cut 1 escapes from the blade when the resistance during cutting is large. However, in the case of the present invention, the cutting resistance is so small that it is not necessarily necessary.

Next, to explain the structure of the cutter 10 in detail, the blade edge 10a needs to be at least longer than the thickness of the material 1 to be cut, and as a guide, the thickness of the material 1 to be cut should be
It is better to set it to 1.3 to 3.0 times. In addition, the sharper the cutting edge, the better the cutting quality, so the cutting edge angle should be set as permissible in terms of rigidity.
Moreover, it is preferable that the pitch is smaller. FIG. 4 shows an example of the structure of a cutter with a very sharp cutting edge 10a'. However, by making the cutting edge sharper and having a larger pitch,
If the speed ratio between the material to be cut 1 and the blade is constant, uncut portions are likely to occur, so in this case, it is necessary to reduce the pitch of the cutting edge or to provide the above-mentioned speed difference.

Next, to explain the cutting action of the apparatus according to the embodiment of the present invention, the blade 10 rotates in the direction of movement of the material 1 to be cut as shown by the arrow in FIG. It is transported as shown in FIG. 1, supported and guided by the support rolls 12, and introduced in the tangential direction of the outer circumference of the cutter 10 to approach the cutter 10. Here, since the circumferential speed of the blade 10 and the transport speed of the material to be cut 1 are slightly different from each other as described above, the blade 10
The cutting blade 10a carved on the outer periphery of the material 1 is cut one after another.
The cutting blade 10a penetrates into the surface of the cutting blade 10a, and is cut while being spread out by the wedge-shaped shape of the cutting blade 10a. That is, the process of first stabbing with the tip of the cutting blade 10a and then tearing with the side cutting blades is repeated.

Since the present invention is configured as explained in detail above, the cutting surface is not crushed unlike the conventional two-blade cutting method or single-blade method, and multiple cutting blades simultaneously cut into the material to be cut. Because it's pushed in, 1
The cutting resistance applied to the blade is small and there is little heat generation. In addition, the cutting surface is not crushed, and the cutting quality is improved, and the deterioration of cutting quality due to softening of the cutting edge due to heat generation, accelerated wear, and the wavering phenomenon of the cutting edge are significantly improved.

[Brief explanation of the drawing]

1A and 1B are explanatory diagrams showing conventional cutting methods, FIG. 1C is an explanatory diagram showing a cutting method using a device showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an embodiment of the present invention. Front view of the cutting device, Figure 3 is the X in Figure 2
-X sectional view, FIG. 4 is a side view showing a part of the cutter of a different embodiment from FIG. 3. Description of the main parts of the figure: 1... Material to be cut, 7... Rotating shaft, 10... Blade, 10a... Cutting blade, 12... Support roll.

Claims (1)

[Claims] 1 Using a rotating disc-shaped thin blade whose cutting edge is longer than the thickness of the material to be cut and has a plurality of teeth with a wedge-shaped sharp tip, the material to be cut is cut in the direction of the outer periphery of the disc-shaped thin blade. A belt-shaped soft material is introduced, and the plurality of cutting edges of the disc-shaped thin blade simultaneously advance and cut each part of the cutting surface by slightly shifting the peripheral speed of rotation of the thin blade and the feed speed of the material to be cut. How to cut the material.