Cutting machine

Abstract

In a running cutting machine equipped with a set of drums, each having a helical blade, the objective is to suppress cutting defects at the start of cutting. [Solution] The running cutting machine (1) has a pair of drums (11, 31) that are arranged opposite each other and can rotate around their respective rotation axes (C1, C2), The system comprises at least one pair of helical blades (21, 41) provided on the outer circumference of each of a pair of drums (11, 31), each having an elliptical arc-shaped cutting edge. At least in the axial direction of each rotation axis (C1, C2), With respect to a reference plane (L1) passing through the respective rotation axes (C1, C2) of a pair of drums (11, 31), the cutting surfaces of a pair of helical blades (21, 41) are offset towards the entry side of the object to be cut, and the cutting surfaces of one and the other are configured to be parallel.

Description

Technical Field

[0001] The present invention relates to a cutting machine for cutting a continuously running metal plate such as a steel strip.

Background Art

[0002] In a metal plate production line, as an example of an in-line cutting machine for cutting a continuously running metal plate, for example, Patent Document 1 discloses a drum shear in which helical blades are mounted opposite to each other on each side surface of a pair of drums that rotate in opposite directions. In the apparatus of Patent Document 1, the helical blades are mounted inclined with respect to the rotation axis of the drum, and the cutting edges of the helical blades are elliptical so that the distance from the rotation axis of the drum to the cutting edges of the helical blades is equal in the axial direction. In addition, in the apparatus of Patent Document 1, the helical blades are mounted perpendicular to the drum surface at the central portion in the longitudinal direction of the drum, and are mounted so that the lap of the cutting edges of the pair of helical blades engages with 0 or minus as the drums rotate in opposite directions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the in-line cutting machine of Patent Document 1, it is said that the strip is cut substantially at a right angle to the running direction, and the equipment cost and maintenance costs such as blade grinding can be reduced.

[0005] However, according to the inter-running cutting machine of Patent Document 1, as shown in Figure 2(b) of Patent Document 1, at the center of the rotation axis of a pair of drums, a pair of helical blades are parallel to each other. However, at positions offset from the center, as shown in Figure 2(a) of Patent Document 1, a pair of helical blades are tilted relative to each other. Starting cutting with a pair of tilted helical blades may result in poor cutting. Patent Document 1 also points out that although cutting is possible with a pair of tilted helical blades, the shape of the cut surface is not good. Based on the above, the present invention aims to suppress cutting defects at the start of cutting in a running cutting machine that comprises a set of drums, each having at least one set of helical blades. [Means for solving the problem]

[0006] The inter-running cutting machine of the present invention A pair of drums are positioned opposite each other and are rotatable around their respective axes of rotation, Each drum is provided with at least one pair of helical blades, each having an elliptical arc-shaped cutting edge, At least in the axial direction of each axis of rotation, With respect to a reference plane passing through the rotation axis of each drum in a pair, the cutting surfaces of a pair of helical blades are offset towards the entry side of the object to be cut, and the cutting surfaces of one and the other are configured to be parallel.

[0007] It is preferable that the cutting surfaces of a pair of helical blades are configured to be parallel at the start of cutting.

[0008] Each of the drums in the set is equipped with a blade groove that holds a helical blade, It is preferable that a base is provided between the helical blade and the bottom surface of the blade groove.

[0009] Preferably, the base is configured such that the horizontal central axis of the helical blade is inclined radially with respect to the rotation axis of the drum.

[0010] The helical blade preferably has a shape that is 2-fold or 4-fold symmetric with respect to an axis passing through the center point of the helical blade.

[0011] The cutting surface of the knife is positioned to contact one side of the groove, and a knife holding member is provided between the other side of the groove and the knife. Preferably, the retaining member is provided so as to contact the side of the knife opposite to the cutting surface, and includes an inclined surface that increases in distance from the knife as it approaches the bottom surface of the blade groove, and a bolt that applies a force to press the inclined surface toward the knife. [Effects of the Invention]

[0012] According to the present invention, the cutting surface of a pair of helical blades is configured to be parallel to a reference plane passing through the rotation axis of each of the pair of drums at the start of cutting. As a result, the running cutting machine according to the present invention can suppress cutting defects at the start of cutting. [Brief explanation of the drawing]

[0013] [Figure 1] This is a front view showing a running cutting machine according to an embodiment. [Figure 2] This is a side view showing a running cutting machine according to an embodiment. [Figure 3] This is a view taken along line III-III in Figure 2. [Figure 4] (a) is a perspective view of the first cutting section with the first knife and first holder removed, and (b) is a perspective view showing the first cutting section with the first knife and first holder assembled. [Figure 5] (a) is a magnified view of the first cutting section, and (b) is a diagram showing the arrangement of the first base and the first knife of the first cutting section from the side of the first wedge. [Figure 6] (a) is a magnified section of Figure 1, and (b) is a magnified section of Figure 3. [Modes for carrying out the invention]

[0014] Hereinafter, with reference to the accompanying drawings, the running cutting machine 1 according to an embodiment of the present invention will be described. The running cutting machine 1 that cuts a cutting target with a set of helical blades is configured such that, in a reference plane, the cutting surfaces of the set of helical blades are parallel at the start of cutting. According to this running cutting machine 1, at the start of cutting of the cutting target, since two cutting surfaces are perpendicular to the cutting target such as a metal plate, cutting defects can be suppressed.

[0015] [Configuration of running cutting machine 1: Refer to FIGS. 1 to 3] The running cutting machine 1 includes a first cutting unit 10 and a second cutting unit 30. The first cutting unit 10 rotates about its first rotation axis C1 (counterclockwise CCW in FIG. 1), and the second cutting unit 30 rotates about its second rotation axis C2 (clockwise CW in FIG. 1). Thus, the first knife 21 provided in the first cutting unit 10 and the second knife 41 provided in the second cutting unit 30 cooperate to cut the cutting target.

[0016] [First cutting unit 10: Refer to FIGS. 1 to 3] The first cutting unit 10 includes a first drum 11 that is rotatable about a first rotation axis C1, a plurality of, for example, six first knives 21 provided on the outer peripheral side of the first drum 11, and a first holder 23 that positions and fixes the first knives 21 to the first drum 11. The first drum 11, the first knives 21, and the first holder 23 are made of a metal material such as steel, for example.

[0017] [First drum: Refer to FIGS. 1 to 3] The first drum 11 includes a first fitting hole 12 formed as a gap into which an output shaft of a rotating electric machine (not shown) is fitted, a first drum main body 14 surrounding the periphery of the first fitting hole 12, and a plurality of first blade grooves 16 recessed from a first outer surface 14B of the first drum main body 14 toward the first rotation axis C1. The first drum main body 14 has a cylindrical form including a first inner surface 14A and a first outer surface 14B. It is rotated about the first rotation axis C1 by a rotating electric machine having an output shaft fitted into the first fitting hole 12 provided inside the first inner surface 14A.

[0018] Multiple, for example, six, first cutting grooves 16 are formed in the first drum 11. Each first cutting groove 16 is formed to intersect the first generatrix 14GL (see Figure 2) on the first outer surface 14B of the first drum 11. This is to make the cutting edge of the first knife 21 helical by intersecting the first generatrix 14GL. In other words, the first knife 21 has a helical cutting edge. The generatrix refers to the line segment that forms the side surface of the rotating body, and the first generatrix 14GL appears on the first inner surface 14A of the first drum body 14. The intersection referred to here means that when the first knife 21 is viewed from a direction perpendicular to the first generatrix 14GL, the cutting edge of the first knife 21 is inclined with respect to the first generatrix 14GL. The same applies to the second knife 41 and the second generatrix 34GL.

[0019] The first cutting groove 16 is formed in the first drum body 14 from one end to the other of the first rotation axis C1. The dimensions of the circumferential CD (width) and radial RD (depth) of the first drum body 14 are set in the first cutting groove 16. The groove is set to accommodate the first knife 21 and the first holder 23, and to be sufficient to fix the first knife 21 inside the first cutting groove 16 by the first holder 23.

[0020] [First knife 21: See Figures 1-3, Figure 5(b)] The first knife 21, together with the second knife 41 of the second cutting section 30, cuts the object to be cut. The first knife 21 has a rectangular parallelepiped shape, and for example, its four corners form the first cutting edges 21E1, 21E2, 21E3, and 21E4. Each of the first cutting edges 21E1, 21E2, 21E3, and 21E4 is elliptical in shape (see Figure 5(b)), and with each first knife 21 held inside the first cutting groove 16, the distance from the first rotation axis C1 of the first drum 11 to each of the first cutting edges 21E1, 21E2, 21E3, and 21E4 is configured to be equal in the direction in which the first rotation axis C1 extends.

[0021] The first knife 21 is equipped with four cutting edges: first cutting edges 21E1, 21E2, 21E3, and 21E4. Therefore, for example, if the first cutting edge 21E1 is used to cut the object but becomes dull due to wear, the orientation of the first knife 21 can be changed so that it can cut with, for example, the first cutting edge 21E2. In this way, a single first knife 21 equipped with four cutting edges can maintain its sharpness over a long period of time simply by changing its orientation without the need for replacement.

[0022] Here, we have shown an example of four-fold symmetry in which the first knife 21 has four first cutting edges 21E1, 21E2, 21E3, and 21E4 with respect to the central axis C21 (see Figure 5(b)) passing through the center point CP of the first knife 21. However, in this embodiment, the first knife 21 can also be a first knife 21 with cutting edges that are two-fold symmetry with respect to the central axis C21, or a first knife 21 with only one cutting edge. The same applies to the second knife 41, which will be described later.

[0023] [First retainer 23: See Figures 3 and 4] The first holder 23 is provided in the first blade groove 16 and positions and fixes the first knife 21 relative to the first drum 11. To achieve this purpose, the first holder 23 includes a first base 24, a first wedge 25, a second wedge 26, and a first liner 27.

[0024] [First base 24: See Figures 4 and 5(b)] The first base 24 is a rectangular parallelepiped member provided between the bottom surface 16BS of the first cutting groove 16 and the first knife 21. When the first base 24 is attached to the first drum 11, it is configured such that the radial dimension RD (wall thickness) in the direction in which the first rotation axis C1 extends increases from one end 24A to the other end 24B. This allows the central axis C21 of the first knife 21 to be tilted radially RD with respect to the first rotation axis C1 of the first drum 11 which is aligned with the horizontal direction H. Multiple first bases 24 of the same specifications (shape, dimensions) can be prepared and used interchangeably for first knives 21 of the same specifications. However, if there are manufacturing tolerances, fine adjustments may be made.

[0025] [First wedge 25, second wedge 26: See Figures 3 and 4] The first wedge 25 and the second wedge 26 can position and fix the first knife 21, whose dimensions have been altered by grinding the first cutting edges 21E1, 21E2, 21E3, and 21E4, without using shims. The first wedge 25 has a front surface 25F and a back surface 25R, with the back surface 25R inclined relative to the front surface 25F to form a taper. Similarly, the second wedge 26 has a front surface 26F and a back surface 26R, with the back surface 26R inclined relative to the front surface 26F to form a taper. When the first wedge 25 and the second wedge 26 are positioned in the first cutting groove 16, the thickness of the first wedge 25 increases from the outside to the inside in the radial direction RD, while the thickness of the second wedge 26 decreases from the outside to the inside in the radial direction RD. In other words, the taper directions of the first wedge 25 and the second wedge 26 are opposite in the radial direction RD. The first wedge 25 and the second wedge 26 are positioned such that the front surface 25F of the first wedge 25 is in contact with the side surface of the first knife 21, the back surface 25R of the first wedge 25 is in contact with the front surface 26F of the second wedge 26, and the back surface 26R of the second wedge 26 is in contact with the first side surface 16S1 of the first blade groove 16.

[0026] If the first wedge 25 and the second wedge 26 are arranged as described above, the first wedge 25 can be pressed toward the first knife 21 by pushing the second wedge 26 from the outside to the inside in the radial direction RD. By fixing the second wedge 26 to the bottom surface 16BS of the first cutting groove 16 with fasteners (not shown), the first liner 27, the first knife 21, the first wedge 25, and the first base 24 can be positioned and fixed in the predetermined positions of the first cutting groove 16.

[0027] [Second cutting section 30: See Figures 1 to 3] Next, the second cutting section 30 will be described. The second cutting section 30 comprises a second drum 31 that is rotatable around a second rotation axis C2, a plurality of second knives 41, for example six, provided on the outer circumference of the second drum 31, and a second holder 43 for attaching the second knives 41 to the second drum 31.

[0028] [Second drum: See Figures 1-3] The second drum 31 comprises a second fitting hole 32 which is a gap into which the output shaft of a rotating electric machine (not shown) is fitted, a second drum body 34 surrounding the second fitting hole 32, and a plurality of second cutting grooves 36 recessed from the second outer surface 34B of the second drum body 34 toward the second rotation axis C2. The second drum body 34 has a cylindrical shape with a second inner surface 34A and a second outer surface 34B. It is rotated around a second rotation axis C2 by a rotating electric machine that has an output shaft fitted into a second fitting hole 32 located inside the second inner surface 34A. In Figures 1 and 3, the second drum body 34 is rotated clockwise (CW).

[0029] Multiple, for example, six, second cutting grooves 36 are formed in the second drum 31. Each second cutting groove 36 is formed to intersect the second generatrix 34GL (see Figure 2) on the second outer surface 34B of the second drum 31. This makes the cutting edge of the second knife 41 spiral (helical) by intersecting the second generatrix 34GL. In other words, the second knife 41, together with the first knife 21, constitutes a helical blade.

[0030] The second cutting groove 36 is formed in the second drum body 34 from one end to the other of the second rotation axis C2. The dimensions of the second drum body 34 are set in the second cutting groove 36, specifically the circumferential CD (width) and radial RD (depth). The groove is set to accommodate the second knife 41 and the second holder 43, and to be sufficient to secure the second knife 41 inside the second cutting groove 36 by the second holder 43.

[0031] [Second knife 41: See Figures 1-3] The second knife 41, together with the second knife 41 of the second cutting section 30, cuts the object to be cut. The second knife 41 has a rectangular parallelepiped shape, and for example, its four corners form the second cutting edges 41E1, 41E2, 41E3, and 41E4. Each of the second cutting edges 41E1, 41E2, 41E3, and 41E4 is elliptical in shape, similar to the first cutting edges 21E1, 21E2, 21E3, and 21E4. With each second knife 41 held inside the second cutting groove 36, the distance from the second rotation axis C2 of the second drum 31 to each of the second cutting edges 41E1, 41E2, 41E3, and 41E4 is set to be equal in the direction in which the second rotation axis C2 extends.

[0032] The second knife 41 is equipped with four cutting edges: second cutting edges 41E1, 41E2, 41E3, and 41E4. Therefore, for example, if the cutting edge 41E1 is used to cut the object but becomes worn and its cutting performance deteriorates, the orientation of the second knife 41 can be changed so that it can cut with the first cutting edge 21E2. In this way, even with the second knife 41 equipped with four cutting edges, cutting performance can be maintained over a long period of time simply by changing its orientation without the need for replacement.

[0033] [Second retainer 43: See Figure 3] The second holder 43 is provided in the second blade groove 36 and positions and fixes the second knife 41 relative to the second drum 31. To achieve this purpose, the second holder 43 includes a second base 44, a third wedge 45, a fourth wedge 46, and a second liner 47.

[0034] [Second pedestal 44] The second base 44 is a rectangular parallelepiped member provided between the bottom surface 36BS of the second cutting groove 36 and the second knife 41. The second base 44 is a rectangular parallelepiped member configured in the same way as the first base 24.

[0035] [Third wedge 45, fourth wedge 46: See Figure 3] The third wedge 45 and the fourth wedge 46 can position and fix the second knife 41, whose dimensions have been altered by grinding the second cutting edges 41E1, 41E2, 41E3, and 41E4, without using shims. The third wedge 45 has a front surface 45F and a back surface 45R, with the back surface 45R inclined relative to the front surface 45F to form a taper. Similarly, the fourth wedge 46 has a front surface 46F and a back surface 46R, with the back surface 46R inclined relative to the front surface 46F to form a taper. The tapers of the third wedge 45 and the fourth wedge 46 are in opposite directions in the radial direction RD. The third wedge 45 and the fourth wedge 46 are positioned such that the front surface 45F of the third wedge 45 is in contact with the side surface of the second knife 41, the back surface 45R of the third wedge 45 is in contact with the front surface 46F of the fourth wedge 46, and the back surface 46R of the fourth wedge 46 is in contact with the second side surface 36S1 of the second cutting groove 36.

[0036] If the third wedge 45 and the fourth wedge 46 are arranged as described above, the third wedge 45 can be pressed toward the second knife 41 by pushing the fourth wedge 46 from the outside to the inside in the radial direction RD. The fourth wedge 46 can be fixed to the bottom surface 36BS of the second cutting groove 36 by fasteners, which are not shown in the figure.

[0037] [Relationship between the first cutting section 10 and the second cutting section 30: See Figures 1 to 3] The first cutting section 10 and the second cutting section 30 are arranged such that the first rotation axis C1 and the second rotation axis C2 are parallel, and the first knife 21 and the second knife 41 are engaged to cut the object to be cut, with the first drum 11 and the second drum 31 facing each other. Furthermore, in the first cutting section 10 and the second cutting section 30, the direction in which the first knife 21 is inclined with respect to the first generatrix 14GL is opposite to the direction in which the second knife 41 is inclined with respect to the second generatrix 34GL (see Figure 2). Note that the first generatrix 14GL and the second generatrix 34GL are parallel. The inclination θ1 (absolute value) of the first knife 21 with respect to the first generatrix 14GL and the inclination θ2 (absolute value) of the second knife 41 with respect to the second generatrix 34GL are equal. By arranging the first knife 21 and the second knife 41 as described above, cutting with a pair of helical blades becomes possible.

[0038] [Relationship between the first knife 21 and the second knife 41: See Figures 6(a) and (b)] When cutting a metal plate or the like is started in the first cutting section 10 and the second cutting section 30, a preferred state for cutting is to make the exit side 21B of the first knife 21 and the entry side 41F of the second knife 41 parallel, as shown in Figure 6(a). The exit side 21B of the first knife 21 and the entry side 41F of the second knife 41 constitute the respective cutting surfaces. In other words, the cutting surfaces of the first knife 21 and the second knife 41 are configured to be parallel to a reference plane L1 passing through the first rotation axis C1 and the second rotation axis C2. If the point where this cutting starts is considered the front end of the first knife 21 and the second knife 41, as the rotation of the first drum 11 and the second drum 31 progresses, the point where the first knife 21 and the second knife 41 mesh shifts to the rear end. Here, as an example of parallelism, an example is shown where the reference plane L1, the exit side 21B, and the entry side 41F coincide. As the first drum 11 and the second drum 31 rotate and the cutting by the first knife 21 and the second knife 41 progresses, the parallel relationship between the first knife 21 and the second knife 41 is broken, and the first knife 21 and the second knife 41 become tilted relative to each other. The "input side" refers to the side from which the object to be cut is sent, while the "output side" refers to the side from which the cut object is sent.

[0039] In FIG. 6(a), the exit surface 21B of the first knife 21 and the entrance surface 41F of the second knife 41 are parallel. However, whether the two blade surfaces are parallel or not can vary depending on the thickness of the object to be cut. That is, assuming that the offset amount is adjusted so that the two blade surfaces are parallel at the start of cutting for an object to be cut A with a plate thickness T1, in the case of an object to be cut B with a plate thickness T2 (> T1) and an object to be cut C with a plate thickness T3 (< T1), the two blade surfaces are displaced from parallel at the start of cutting. However, even in the case of the object to be cut B and the object to be cut C, the two blade surfaces are parallel before and after the start of cutting. This suggests that by appropriately adjusting the offset amount, the two blade surfaces can be made parallel at the start of cutting for objects to be cut with different plate thicknesses. Here, the offset amount refers to the distance between the exit surface 21B or the entrance surface 41F and the reference plane L1. As an example, even if the offset amount is adjusted to 21 mm assuming an object to be cut with a plate thickness of 2.5 mm, by increasing or decreasing the offset amount from 21 mm, the two blade surfaces can be made parallel at the start of cutting for an object to be cut with a plate thickness of 3.5 mm and an object to be cut with a plate thickness of 1.5 mm.

[0040] At the axial center of the first rotation axis C1 and the second rotation axis C2, as shown in FIG. 6(b), the first knife 21 and the second knife 41 are in a positional relationship shifted in the advancing direction of the object to be cut. The first knife 21 is arranged such that the plane L2 including the line segment extending the entrance surface 41F of the second knife 41 coincides with the exit surface 21B. That is, the first knife 21 is arranged on the entrance side relative to the second knife 41. And with respect to the reference plane L1, the exit surface 21B of the first knife 21, which is the cutting surface, and the entrance surface 41F of the second knife 41 are offset to the entrance side of the object to be cut. By having this offset relationship of the cutting surface, a parallel relationship between the first knife 21 and the second knife 41 involved in cutting is realized when starting the cutting. In FIG. 6(b), although the exit surface 41B of the second knife 41 is shown to coincide with the reference plane L1, actually, it is arranged with a displacement corresponding to the difference between the offset amount and the thickness of the second knife 41.

[0041] [Effects achieved by the embodiment] [First effect: The effect of having a pair of knives parallel to each other] In the running cutting machine 1, the cutting surfaces of the first knife 21 and the second knife 41 are configured to be parallel to a reference plane L1 passing through the first rotation axis C1 and the second rotation axis C2 at the start of cutting. In this way, the cutting surface of the first knife 21 (exit side 21B) and the cutting surface of the second knife 41 (inside side 41F) are parallel to the thickness of the metal plate being fed in from the input side, and the two cutting surfaces are perpendicular to the metal plate, thus suppressing cutting defects. Although we have described the ideal case where the two cross-sections are parallel, we will allow for a slight inclination between the two cross-sections.

[0042] [Second effect: Effects of providing the first base 24 and the second base 44] In the running cutting machine 1, the first knife 21 and the second knife 41 are offset from each other. This offset requires that the elliptical shape of the cutting edges of the first knife 21 and the second knife 41 be slightly deviated from symmetrical. In response to this, by providing the first base 24 and the second base 44, the central axes (long axes) of the first knife 21 and the second knife 41 are supported so as to be tilted radially RD with respect to the first rotation axis C1 and the second rotation axis C2, respectively, thereby compensating for the deviation in the elliptical arc shape of the cutting edges.

[0043] [Third effect: Effect due to the four-fold symmetrical shape of the first knife 21 and the second knife 41] The first knife 21 (second knife 41) has cutting edges that are four times symmetrical with respect to an axis passing through the center point. Therefore, by changing the orientation of a single first knife 21 (second knife 41), four cutting edges can be used, thereby reducing the cost of cutting. Here, we have mentioned four-fold symmetry as the most preferred example, but it is also possible to use a first knife 21 (second knife 41) with a blade edge that is two-fold symmetrical.

[0044] [Fourth effect: Effects of the first holder 23 and the second holder 43] The first knife 21 and the second knife 41 regenerate their cutting edges by grinding them in the thickness direction with continued use. Therefore, the thickness of the first knife 21 and the second knife 41 decreases with continued use. To address this, the running cutting machine 1 is equipped with two wedges (first wedge 25 and second wedge 26) with opposite taper directions on the first holder 23, and two wedges (third wedge 45 and fourth wedge 46) with opposite taper directions on the second holder 43. As a result, even if the first knife 21 and the second knife 41 become thinner, the positioning and fixing of the first knife 21 and the second knife 41 corresponding to the grinding allowance can be achieved simply by inserting the two wedges into the first cutting groove 16 and the second cutting groove 36. For example, the positioning and fixing of the first knife 21 and the second knife 41 can also be achieved by preparing shims corresponding to the polishing allowance. However, in this case, it is necessary to prepare shims corresponding to the polishing allowance each time polishing is performed, which is time-consuming.

[0045] In addition to the above, it is possible to select or replace the configurations listed in the above embodiments, or to change them to other configurations as appropriate, as long as it does not deviate from the spirit of the present invention. For example, in this embodiment, the first knife 21 is positioned on the entry side relative to the second knife 41, but the reverse is also possible, where the second knife 41 is positioned on the entry side relative to the first knife 21. [Explanation of symbols]

[0046] 1 Running cutting machine 10 1st cutting section 11 First Drum 12 First fitting hole 14. Main body of the first drum 14GL 1st bus bar 14A First inner surface 14B 1st outer surface 16 First cutting edge groove 16 16BS bottom 16S1 First side 21 First Knife 21E1, 21E2, 21E3, 21E4 First cutting edge 23 1st holder 24. First Pedestal 25. First Wedge 25F Front 25R Reverse side 26. Second wedge 26F Front 26R Reverse side 27 First Liner 30 Second cutting section 31. Second Drum 32 Second fitting hole 34. Second drum unit 34GL 2nd bus bar 34A 2nd inner surface 34B 2nd outer surface 36. Second cutting edge groove 36S1 2nd side 36BS bottom 41 Second knife 41 41E1, 41E2, 41E3, 41E4 Second cutting edge 43 Second holder 44. Second Pedestal 45 Third wedge 45 45F Front 45R Reverse side 46 4th wedge 46 46F Front 46R Reverse side 47 Second Liner C1 First rotation axis C2 Second rotation axis CD circumferential direction RD radial direction

Claims

1. A pair of drums are positioned opposite each other and are rotatable around their respective axes of rotation, The drum comprises at least one pair of helical blades, each having an elliptical arc-shaped cutting edge, provided on the outer circumference of each of the drums, At least in the axial direction of each of the aforementioned rotation axes, A running cutting machine configured such that the cutting surfaces of a pair of helical blades are offset toward the entry side of the object to be cut with respect to a reference plane passing through the rotation axis of each of the pair of drums, and that one cutting surface and the other cutting surface are parallel.

2. The cutting surfaces of a set of helical blades are configured to be parallel at the start of cutting. The inter-running cutting machine according to claim 1.

3. Each of the drums in the set is provided with a groove in which the helical blade is held, A base is provided between the helical blade and the bottom surface of the blade groove. The inter-running cutting machine according to claim 1.

4. The base is configured such that the horizontal central axis of the helical blade is inclined radially with respect to the rotation axis of the drum. The inter-running cutting machine according to claim 3.

5. The helical blade has a shape that is 2-fold or 4-fold symmetric with respect to an axis passing through the center point of the helical blade. A running cutting machine according to any one of claims 1 to 4.

6. The helical blade is provided with a holder for positioning and fixing it in the blade groove, The aforementioned holder is The drum is provided with a pair of wedges in which the direction of the taper is opposite in the radial direction. The inter-running cutting machine according to claim 3 or claim 4.

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