JPH0725059B2 - Rotary cutter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is required for cutting a sheet-like material such as a corrugated cardboard sheet, which continuously flows in one direction, in a direction intersecting with a transport direction. The present invention relates to a rotary cutter that forms a sheet of length. 2. Description of the Related Art As shown in FIG. 7, the rotary cutter is a pair of rolls 20 and 2 which are synchronously rotated in opposite directions.
Attach the long knives 21, 21 to the outer peripheral surface of 0,
The pair of knives 21 and 21 cuts the sheet A continuously supplied between the rolls 20 in the width direction. When a corrugated cardboard sheet is cut using the rotary cutter as described above, a pair of rolls 20 is used.
Is rotated at a non-constant speed to cut the corrugated cardboard sheet into a desired length. That is, in a range I from a position where the knives 21 stop immediately above the upper roll 20 to the time when both knives 21 start to contact each other, the knives 21 are accelerated to the traveling speed of the corrugated board sheet A, and the pair of knives 21 cut the corrugated board sheet A. Range from the position to start cutting to the completion of cutting
In II, the traveling speed is the same as that of the corrugated board sheet A, and the range in which the knife 21 reaches right above the roll 20 after completion of cutting.
In III, the speed control of both knives 21 is performed in three stages so as to rotate deceleratingly. Acceleration time, deceleration time, and stop within a single cycle depending on the cutting length of corrugated cardboard sheet A running at high speed. I try to control the time accurately. Naturally, the traveling speed of the corrugated board sheet A is not always constant. In general, in order to control the rotation speed of a rotating body, the moment of inertia, so-called GD ² value is made as small as possible to improve the response to speed to achieve high speed, and the motor used is small in size. Is preferable. Therefore, in the rotary cutter that controls the rotation speed of the roll 20 as described above, it is preferable to make the outer diameter of the roll 20 as small as possible to make it lightweight, but if the roll diameter is made small, the rigidity decreases. Therefore, the roll 20 is bent or bent due to an impact when the corrugated board sheet A is cut, and the sharpness of the knife 21 is deteriorated. If the outer diameter of the roll 20 is increased to improve the sharpness, a roll driving motor having a small GD ² and a large output torque is required. However, there is a limit to the development of a large-capacity motor that meets such conditions, and there is still no motor that can be satisfied. In order to solve such a problem, in JP-A-57-48492, a roller provided with a knife is made hollow so as to be lightweight, and both ends of a shaft inserted inside the hollow roller are arranged. It is supported by a frame, and the hollow roller is rotatably supported by interposing a plurality of bearings between the shaft and the hollow roller, so that the shaft receives the impact when cutting the corrugated cardboard sheet and prevents the hollow roller from bending. A rotary plate-shaped material cutting device is disclosed. Further, in Japanese Patent Application Laid-Open No. 57-138591, a roller provided with a knife is made hollow, and both ends of a shaft inserted inside thereof are supported by a frame, and the roller is rotatably supported by the roller. Disclosed is a rotary plate-shaped material cutting device in which a body is brought into contact with a shaft, and the shaft receives an impact when the corrugated cardboard sheet is cut to prevent the hollow roller from bending. [0007] In any of the above-mentioned cutting devices, since the roller rotated by the motor is hollow, there is an advantage that a small drive motor can be used. However, since it is necessary to insert a shaft inside the roll to provide a required gap between them, there is a disadvantage that the roll diameter becomes large and the minimum cutting length at high speed becomes long. Generally, the minimum cut length of the roll at the maximum speed is considered to be limited to 90 to 95% of the roll circumference. Further, since the roll diameter is large, GD ² cannot be reduced much, and satisfactory problems have not yet been solved in terms of high-speed roll control and motor miniaturization. Therefore, the present invention solves the above-mentioned inconveniences, reduces the minimum cutting length of the sheet-like material, and reduces GD ² to improve the control response to speed up the cutting control and downsize the motor. It is considered a technical issue to measure. In order to solve the above-mentioned problems, according to the present invention, each of the rollers equipped with a knife comes into contact with the outer peripheral surface of the roll when the sheet-like material is cut. A structure is provided in which a rotating body that receives an impact at the time of cutting that is applied to the roll is arranged, and an avoiding unit that avoids a collision between the rotating body after the cutting and the next rotating cutting and the rotating body is provided. Here, the avoidance means is provided with a cutout portion in which a knife can be fitted on a part of the outer circumference of the rotating body, and the rotating body is rotated in time with the roll so that the knife fits into the cutout portion. Alternatively, the rotating body may be supported so as to come into contact with or separate from the outer peripheral surface of the roll, and the rotating body may be separated from the outer peripheral surface of the roll by the operation of the rotating body moving mechanism. . As described above, when the pair of knives cuts the sheet-like material, the rotating body is brought into contact with the outer peripheral surface of the roll, so that the rotating body supports the impact at the time of cutting. be able to. Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, a pair of upper and lower rolls 2 and 2 ′ whose both ends are supported by frames 1 and 1 are mutually engaged by meshing of a gear 4 fixed to an end of a roll shaft 3. It is rotated in the opposite direction synchronously. Each roll 2,
On the outer peripheral surface of 2 ', an axially long knife 5 is attached,
The knife 5 cuts the sheet material continuously supplied between the pair of rolls 2 and 2 '. Upper and lower rolls 2'of the upper roll 2
A gate-shaped support frame 6 is provided in the lower part of the, and a plurality of brackets 7 are attached to the inner periphery of the support frame 6. Each of the brackets 7 has a roll 2,
A support shaft 8 provided in parallel with 2 ′ is rotatably supported, and a rotary body 9 that comes into contact with the outer circumference of the upper roll 2 and the outer circumference of the lower roll 2 ′ is attached to each support shaft 8. A notch 10 into which the knife 5 can fit is provided. The rotating body 9 is rotated at the same peripheral speed as the roll bodies 2 and 2'by engagement of a gear 11 attached to the end of the support shaft 8 and a gear 12 attached to the end of the roll shaft 3, Moreover, the knife 5 is rotated in time with the roll bodies 2 and 2 ′ so that the knife 5 fits well in the notch 10. Now, by rotating the pair of rolls 2 and 2'in opposite directions and supplying a sheet-like material such as a corrugated cardboard sheet toward the pair of rolls 2 and 2 ', each roll 2, The sheet-shaped material can be cut by a pair of knives 5 provided on 2 ', and the cutting length of the sheet-shaped material can be arbitrarily controlled by controlling the rotation speed of the rolls 2, 2'. The impact of cutting such a sheet-like material acts on each of the rolls 2 and 2 ', but since the rotating body 9 is in contact with the outer peripheral surfaces of the rolls 2 and 2', the impact is rotated. It acts on the body 9. Therefore, it is possible to prevent the rolls 2 and 2 ′ from being bent by the impact at the time of cutting, and the pair of knives 5 can surely cut the sheet-shaped material. Further, as shown in FIG. 3, when the knife 5 rotates to the position of the rotating body 9, the notch 10 faces the knife 5, and the knife 5 fits into the notch 10, so that the knife 5 is The sheet-like material can be reliably cut without interfering with the rotating body 9. In the embodiment shown in FIGS. 1 to 3, the rotary member 9 is used.
Although the notch 10 is formed in the notch 10 and the knife 5 is fitted into the notch 10 to avoid the knife 5 colliding with the rotating body 9, the collision avoiding means is not limited to this. . For example, as shown in FIGS. 4 to 6, the roll 2 is attached to the bracket 13 attached to the support frame 6,
A long hole 14 is formed in a direction orthogonal to the radial direction of 2 ', and the rolls 2, 2'are mounted on the support shaft 8 inserted in the long hole 14.
A cam 15 in which a rotating body 9 that can come into contact with the outer circumference of
Alternatively, the rotating body 9 may be pushed up to separate from the outer circumference of the rolls 2 and 2 ′, and the support shaft 8 may be deflected by the elastic force of the spring 16 to bring the rotating body 9 into contact with the outer circumferences of the rolls 2 and 2 ′. The means for bringing the rotating body 9 into contact with and separating from the rolls 2 and 2'is not limited to the above configuration, and any other mechanism can be adopted. As described above, according to the present invention, the impact applied to the roll at the time of cutting the sheet-like material is received by the rotating body in contact with the outer peripheral surface of the roll, so that the sheet-like material is cut. Sometimes there is no inconvenience that the roll bends, and the pair of knives can surely cut the sheet-like material. Further, since the rotating body is brought into direct contact with the outer peripheral surface of the roll and the rotating body receives an impact at the time of cutting, as compared with the case where the rotating body is brought into contact with the protrusion provided on the outer periphery of the roll, The weight is light and the outer diameter can be made as small as possible. Therefore, the minimum cutting length of the sheet material can be made shorter than that of the conventional one, and the GD
² can be reduced, and the rotation control of the roll can be speeded up and the motor can be downsized. Further, by providing the avoiding means for avoiding the impact between the rotating body and the knife, which receives the impact at the time of cutting, the knife which rotates and moves from after cutting the sheet-like material to the next cutting interferes with the rotating body. Therefore, the cutting work can be reliably performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional front view showing an embodiment of a rotary cutter according to the present invention. FIG. 2 is a vertical sectional side view of the same. FIG. 3 is a vertical sectional side view showing an operating state of the same. 4] A front view showing another embodiment of the above rotary cutter [Fig. 5] A vertical side view of the same [Fig. 6] A vertical side view of the same working state [Fig. 7] An explanatory view of the action of the rotary cutter Description] 2, 2'Roll 5 Knife 9 Rotating body 10 Notch

Claims (1)

Claims: (1) A long knife is attached to the outer circumference of each of a pair of rolls that are rotated in opposite directions in synchronism with each other, and a pair of rolls is rotatably moved between the pair of rolls during intermittent meshing. In a rotary cutter configured to cut a continuously supplied sheet material in a direction intersecting the transport direction, each of the pair of rolls is in contact with an outer peripheral surface of the roll when the sheet material is cut. A rotary cutter provided with a rotating body which receives an impact at the time of cutting applied to the rolls, and which is provided with an avoiding means for avoiding a collision between the knife and the rotating body which is rotationally moved from one cutting to the next cutting. . (2) The avoiding means is provided with a notch portion in which a knife can be fitted on a part of the outer circumference of the rotating body, and a mechanism for rotating the rotating body at a timing with a roll so that the knife fits into the notch portion. The rotary cutter according to claim 1 having the above structure. (3) A rotating body moving mechanism in which the avoiding means supports the rotating body such that the rotating body can come into contact with and separate from the outer peripheral surface of the roll, and moves the rotating body in a direction away from the outer peripheral surface of the roll when the knife passes. The rotary cutter according to claim 1, wherein the rotary cutter is provided.