Rotary cutting machine's paper crease correction mechanism
The fixed rectangular rod in the paper curl correction mechanism addresses the weakness of rotating round rods by enhancing curl correction force and preventing metal wear, ensuring effective curl removal.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- NATIONAL PRINTING BUREAU
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-29
AI Technical Summary
Conventional paper curl correction mechanisms using a rotating round rod as a pressing member are ineffective due to weakened pressure, which results in insufficient curl correction force.
The pressing member is replaced with a fixed rectangular rod, which can be of various polygonal cross-sections, including a square, to enhance the vertical pressing force and prevent metal-to-metal contact, thereby improving curl correction.
The fixed rectangular rod provides enhanced curl correction force and prevents metal wear, ensuring effective curl removal without generating iron powder, thus maintaining paper quality.
Smart Images
Figure 2026105897000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a paper curl correction mechanism for correcting the curl of a wound parent reel produced by a paper machine and finishing it into a flat size by cutting the wound parent reel with a rotary cutting device.
Background Art
[0002] Conventionally, when cutting a wound parent reel produced by a paper machine into a flat size, a paper curl correction mechanism is used to correct the curl shape (hereinafter referred to as "curl") when the wound parent reel is unwound. The paper curl correction mechanism contacts the pressing member of the curl correction part on the non-curl side of the paper unwound from the wound parent reel, and the non-curl side is squeezed by the curl correction part to forcibly remove the curl and correct it to a state without curl. The wound parent reel is corrected for curl on the front side of the cutting process and then cut into a flat size. The non-curl side of the paper is the side opposite to the side where the paper warps along the roll when it is wound around the roll and becomes a wound parent reel.
[0003] For example, as shown in the front view of FIG. 1(a) and the cross-sectional view of FIG. 1(b), a conventional paper curl correction mechanism (B1) includes a bearing (6a) attached to a frame (F1), and both ends of a round rod (5), which is a pressing member rotatably supported by the bearing (6a), are attached to a frame (F2) via a bearing (6b).
[0004] Furthermore, as shown in FIG. 2, the paper curl correction mechanism (B1) rotates and presses a round rod (5) as a pressing member against the non-curl side of the paper (W) conveyed through a conveying roller (P1) and a conveying roller (P2) to forcibly remove the curl and correct it to a state without curl. Further, the paper curl correction mechanism (B1) moves up and down in the vertical direction (Z) in accordance with the paper curl of the paper (W) with respect to the change in the roll diameter of the wound parent reel, and adjusts the holding angle ((θ2) (the angle at which the round rod (5) contacts the paper (W))) with respect to the paper (W).
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, the paper curl correction mechanism (B1) shown in Figure 1 had a problem in that the round rod (5), which is the pressing member, rotates in the same way as the moving paper (W), so the pressure on the paper (W) is weakened and the force to correct the curl is insufficient.
[0006] The present invention aims to solve the above problems by configuring the pressing member of the paper curl correction mechanism (B1) with a fixed corner member, thereby improving the force used to correct the curl of the paper (W). [Means for solving the problem]
[0007] The present invention relates to a rotary cutting device that cuts rolls of raw paper manufactured by a paper machine into flat sheets in a cutting process, and features a paper curl correction mechanism that corrects the curl of the rolls of raw paper by pressing them with a pressing member fixed to the frame of the rotary cutting device in a process prior to the cutting process, wherein the pressing member is a rectangular rod. [Effects of the Invention]
[0008] The present invention improves the force used to correct the curl of paper (W) by forming the pressing member of the paper curl correction mechanism (B1) with a fixed rectangular rod (2). [Brief explanation of the drawing]
[0009] [Figure 1] An example diagram showing the configuration of a conventional paper crease correction mechanism (B1). [Figure 2] An example diagram showing the operation of a conventional paper crease correction mechanism (B1). [Figure 3] An example diagram showing the configuration of the paper curl correction mechanism (A1) of the present invention. [Figure 4] An example diagram illustrating the operation of the paper crease correction mechanism (A1) of the present invention. [Modes for carrying out the invention]
[0010] First, the paper curl correction mechanism (A1) of the present invention will be explained with reference to the front view shown in Figure 3(a) and the cross-sectional view shown in Figure 3(b). As shown in Figures 3(a) and 3(b), the paper curl correction mechanism (A1) consists of a rectangular rod (2) having a rectangular cross-sectional shape (3) fixed at both ends to a frame (F2).
[0011] As shown in Figure 3(b), the pressing member, the rectangular rod (2), can be any polygon in which the interior angle (θ1) of the cross-sectional shape of the corner (3) is at least one right angle, obtuse angle, or acute angle. Known shapes such as triangles, rectangles, squares, and rhombuses can be used.
[0012] By making the interior angle (θ1) of the cross-sectional shape of the rectangular rod (2) a right angle or an acute angle, the vertical pressing force of the side corner (3) against the paper (W) can be increased compared to the conventional round rod (5).
[0013] The preferred cross-sectional shape of the rectangular rod (2) is a square. When the cross-sectional shape is a square, there are four corners (3), so even if one corner (3) wears down, the other corners (3) can still be used.
[0014] The rectangular rod (2) is made of iron, or an iron surface with a hardened coating layer of carbide ceramic. The carbide ceramics are titanium carbide, silicon carbide, and tungsten carbide. By using these carbide ceramics, wear resistance can be improved. The thickness of the hardened coating layer should be at least 200 μm. If it is less than 200 μm, the hardened coating layer may peel off due to wear.
[0015] Furthermore, since the rectangular rod (2) is fixed to the frame (F2) at both ends, it does not rotate via the bearings (6a) and (6b) compared to the conventional round rod (5). As a result, the metal-to-metal contact between the round rod (5) and the holding bearing (6a) does not occur, and iron powder that adheres to the paper (W) due to deterioration can be prevented.
[0016] Next, an example of the operation of the paper curl correction mechanism (A1) of the present invention will be described.
[0017] As shown in FIG. 4, the paper curl correction mechanism (A1) of the present invention presses the corner (3) on the side surface of the square rod (2), which is a pressing member, in the vertical direction (Z) against the non-curling surface side of the paper (W) being conveyed via the conveying roller (P1) and the conveying roller (P2), forcibly removing the curl and correcting it to a non-curled state.
[0018] The paper curl correction mechanism (A1) may be provided with a function of measuring the change in the roll diameter of the winding original roll by an encoder, and moving up and down in the vertical direction (Z) in accordance with the paper curl of the paper (W) with respect to the change in the roll diameter of the winding original roll to adjust the pressing force on the paper (W). Specifically, as the roll diameter of the winding original roll decreases, the square rod (2) is lowered in the vertical direction (Z) to increase the pressing force of the square rod (2), which is a pressing member, on the paper (W). In addition, the adjustment of the pressing force by the square rod (2) may be adjusted by predicting the curling state in the state where it is cut and has a flat size, recording the moisture content and basis weight of the paper at the time of manufacturing the winding original roll in the information terminal in advance, and predicting the curling state from the record, or adjusting according to the predicted value obtained by measuring the curling state after cutting and having a flat size.
[0019] Therefore, by forming the pressing member with a fixed square rod (2), the paper curl correction mechanism (A1) of the present invention improves the correction force for the paper (W), and without using the bearings (6a) and the bearings (6b), by fixing it to the frame (F2), it is possible to prevent the occurrence of dirt due to iron powder associated with deterioration due to contact between metals.
Explanation of Signs
[0020] A1 Paper curl correction mechanism B1 Paper curl correction mechanism 2 Square rod 3 Side corner 5 Round rod 6a, 6b Bearings P1, P2 conveyor rollers Z vertical direction W paper F1, F2 Frame θ1 interior angle θ2 angle of embrace
Claims
[Claim 1] In a rotary cutting machine that cuts rolls of raw material produced by a paper machine into flat sheets in a cutting process, A paper curl correction mechanism that corrects the curl of the rolled raw material by pressing it with a pressing member fixed to the frame of the rotary cutting device in a step prior to the cutting process, The aforementioned pressing member is a rectangular rod, which is a paper curl correction mechanism.