Friction shaft for slitter

Abstract

The present invention relates to a friction shaft for a slitter, which has a winding tube on its outer surface for winding up unit materials formed by cutting raw materials such as various types of paper, fabric, and film at predetermined intervals into rolls.The rotating shaft includes a first main body portion that constitutes the main body, a plurality of main flow paths that pass through the first main body portion along the longitudinal direction and have different lengths, and a plurality of sub-flow paths that connect the plurality of main flow paths to the outside of the first main body portion.

Description

[Technical Field]

[0001] The present invention relates to a friction shaft, and more particularly to a friction shaft for a slitter, which has a winding tube on its outer surface for winding up unit pieces formed by cutting raw materials such as various types of paper, fabric, and film at predetermined intervals into rolls. [Background technology]

[0002] A slitter is a device that cuts rolled raw materials such as textiles, paper, and synthetic resin films along the longitudinal direction while unwinding them.

[0003] The raw material is cut into a number of small width units by a slitter and wound up in a roll before being supplied.

[0004] When using a slitter, the multiple divided unit materials must be individually wound onto the outer surface of the corresponding winding tube, but it is difficult to wind all the unit materials with uniform torque using a single rotating shaft.

[0005] If all the units are wound on a single rotating shaft, the units will be wound unevenly around the winding tube, with some being wound loosely and some being wound too tightly.

[0006] Therefore, the former has the problem that the roll is unwound during supply or use, and the latter has the problem that the unit material is broken or stretched.

[0007] When expensive films are stretched, they can lose their merchantability, resulting in great losses.

[0008] Therefore, a winding device is provided for winding all the unit materials with a uniform torque.

[0009] The important component of the shaft used here is usually called a friction shaft, and is also called an air friction shaft because it mostly uses air pressure.

[0010] In this regard, Korean Patent Publication No. 10-2014-0083406 (July 4, 2014) discloses a winding device including a rod-shaped winding shaft rotated by a winding motor, a first hole drilled inside the winding shaft along the longitudinal direction of the winding shaft, a plurality of third holes drilled on the outer circumferential surface of the winding shaft so as to communicate with the first hole and spaced apart along the extension direction of the first hole, a plurality of holders each having a short tube shape fitted to the inner periphery of a paper tube for winding unit materials and fitted sequentially to the outer periphery of the winding shaft, the holders being installed at positions where the third holes are provided, and a first air pressure generating unit that supplies compressed air to the first hole so that the holders apply pressure to the paper tube. The friction shaft for a slitter includes: a holder base in the form of a short tube, with a plurality of lug seating grooves formed along its outer periphery, and with communication holes formed by drilling to connect the third hole with the lug seating grooves; a lug that fits into the lug seating groove so as to rise along the radial direction of the winding shaft; a spring, one end of which is supported by the lug and the other end of which is supported by the lug seating groove, so that the lug receives a force that elastically tends to protrude along the radial direction of the winding shaft; a fixed cover that is fixed to the holder base while pressing the outer periphery of the lug to prevent the lug from coming out of the lug seating groove; and air pressure guide means that guides compressed air supplied to the first hole so that the lug is pressed toward the center of the winding shaft.

[0011] The air pressure generated by the air compressor of such a friction shaft flows into the interior of the winding shaft from an air pressure generating section engaged with one end of the winding shaft.

[0012] Furthermore, the air pressure flowing in from one end of the winding shaft causes a plurality of lugs arranged along the longitudinal direction of the winding shaft to protrude from the outer peripheral surface of the winding shaft.

[0013] On the other hand, in such a conventional friction shaft, air flows in from one end of the winding shaft.

[0014] In this case, even if air of the same pressure is supplied to each holder from one end of the winding shaft, there is a problem that variations in torque occur in each holder due to various causes such as assembly tolerances of each component such as the retainer and bearings that make up the friction shaft, surface roughness, heat generated during product operation, wear, and clogging with foreign matter.

[0015] This has conventionally resulted in a problem in that the unit material is wound unevenly around the winding tube.

[0016] Therefore, some are wound loosely and some are wound too tightly, the former causing problems such as the roll unwinding during supply or use, and the latter causing problems such as breakage or stretching of the unit material. For the reasons mentioned above, the field has been searching for a method for winding the unit material uniformly onto the winding tube, but the reality is that no satisfactory results have been obtained to date. Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention has been made to solve the above-mentioned problems, and its object is to provide a friction shaft for a slitter that can uniformly wind unit materials around a winding tube.

[0018] The above and other objects, advantages and features of the present invention, as well as the manner in which they are achieved, will become apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. [Means for solving the problem]

[0019] In order to achieve the above-mentioned object, one embodiment of the present invention provides a friction shaft for a slitter, which has a winding tube on its outer surface for winding up unit materials formed by cutting raw materials such as various types of paper, fabric, and film at predetermined intervals into rolls. The friction shaft includes: a rotating shaft that is rotated by a drive motor and to which compressed air is supplied from an air supply unit; a plurality of short-tube-shaped friction cores that are attached to the rotating shaft in a line; lug portions that are attached to the friction cores so that they are spaced equally apart along the axial direction of the rotating shaft; and a rotary joint that is connected to the end of the rotating shaft and supplies air supplied from the air supply unit to the rotating shaft. The rotating shaft includes a first main body portion that constitutes a main body; a plurality of main flow paths that penetrate the first main body portion along the longitudinal direction and have different lengths; and a plurality of sub-flow paths that connect the plurality of main flow paths to the outside of the first main body portion.

[0020] The friction core includes a second body portion forming a main body, an insertion hole that penetrates the second body portion radially and into which the lug portion is inserted, a plurality of seating holes that are equally spaced apart along the circumferential direction of the rotating shaft in positions in the second body portion that do not overlap with the through hole, and a plurality of roller portions seated in the seating holes.

[0021] The friction core further includes a retainer support mounted adjacent to the rotary shaft, and a retainer supported by the retainer support and generating torque by air pressure introduced from the outside.

[0022] The plurality of friction cores are composed of four first cores arranged in a first region which is one end where the rotary joint is connected, four second cores arranged in a second region which is adjacent to the first region in a region opposite to the position where the rotary joint is connected based on the first region, four third cores arranged in a third region which is adjacent to the second region in a region opposite to the position where the rotary joint is connected based on the second region, and four fourth cores arranged in a fourth region which is adjacent to the third region in a region opposite to the position where the rotary joint is connected based on the third region.

[0023] The plurality of friction cores are attached to the first body portion in sequence.

[0024] The main flow passages include a first main flow passage that penetrates from one end where the rotary joint is coupled to a first region, a second main flow passage that does not overlap with the first main flow passage and penetrates from one end where the rotary joint is coupled to a second region, a third main flow passage that does not overlap with the first main flow passage and the second main flow passage and penetrates from one end where the rotary joint is coupled to a third region, and a fourth main flow passage that does not overlap with the first main flow passage to the third main flow passage and penetrates from one end where the rotary joint is coupled to a fourth region.

[0025] The sub-channels include a first sub-channel formed in a first region of the first main channel, a second sub-channel formed in a second region of the second main channel, a third sub-channel formed in a third region of the third main channel, and a fourth sub-channel formed in a fourth region of the fourth main channel.

[0026] The rotation shaft may further include a plurality of grooves formed on an outer circumferential surface of the first body portion along a longitudinal direction thereof and communicating with the sub-channels.

[0027] The recesses are formed in the first sub-channel, the second sub-channel, the third sub-channel, and the fourth sub-channel, respectively.

[0028] The lug portion includes an upper lug whose upper surface contacts the inner peripheral surface of the winding tube when compressed air flows in from the air supply portion to chuck the winding tube; a connecting portion extending downward from the lower surface of the upper lug; a lower lug having a seat formed on its upper surface and extending from a lower end of the connecting portion to both ends in the circumferential direction of the rotating shaft; and an elastic member whose one end is seated on the seat and whose other end contacts the inner peripheral surface of the second main body portion.

[0029] The elastic member is a compression spring.

[0030] The rotary joint includes a third main body portion forming a main body, a first communication hole penetrating one end and the other end of the third main body portion and communicating with the first main flow path, a second communication hole penetrating one end and the other end of the third main body portion and communicating with the second main flow path, a third communication hole penetrating one end and the other end of the third main body portion and communicating with the third main flow path, and a fourth communication hole penetrating one end and the other end of the third main body portion and communicating with the fourth main flow path. [Effects of the Invention]

[0031] According to the present invention, a plurality of main flow paths are respectively connected to a plurality of friction cores provided in various regions, and different air pressures flow into each of the plurality of friction cores, so that the torque generated by the air pressure is applied to each of the plurality of friction cores, thereby reducing the variation in torque of each of the plurality of friction cores. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a perspective view showing a friction shaft for a slitter according to an embodiment of the present invention. [Figure 2]1 is a cross-sectional view of a friction shaft for a slitter according to an embodiment of the present invention. [Figure 3] FIG. 4 is a cross-sectional view of a friction shaft for a slitter according to another embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view showing a rotary shaft and a rotary joint of a friction shaft for a slitter according to an embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view taken along the line AA' shown in FIG. 4. [Figure 6] FIG. 5 is a cross-sectional view taken along the line BB' shown in FIG. 4. [Figure 7] FIG. 2 is a perspective view showing a lug portion of a friction shaft for a slitter according to an embodiment of the present invention. [Figure 8] FIG. 3 is an enlarged view showing a portion A shown in FIG. 2. [Figure 9a] 4 is a diagram illustrating the operation of a friction shaft for a slitter according to an embodiment of the present invention. FIG. [Figure 9b] 4 is a diagram illustrating the operation of a friction shaft for a slitter according to an embodiment of the present invention. FIG. [Figure 10] FIG. 10 is a perspective view showing a rotating shaft according to another embodiment of the present invention. [Figure 11] 11 is a cross-sectional view taken along the line CC' shown in FIG. 10. FIG. [Figure 12] 11 is a cross-sectional view taken along the line DD' shown in FIG. 10. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0033] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following embodiments can be modified into various other forms, and the scope of the present invention is not limited to the following embodiments. Rather, these embodiments are provided to make the present disclosure more complete and complete, and to fully convey the concept of the present invention to those skilled in the art. In addition, the configurations in the following drawings are exaggerated for convenience and clarity of explanation, and the same elements are designated by the same reference numerals in the drawings. As used in this specification, the term "and / or" includes any one of the listed items and all combinations of one or more of the listed items.

[0034] The terms used in this specification are used to describe particular embodiments and are not intended to limit the present invention.

[0035] As used herein, the singular forms "a," "an," and "the" can include the plural forms unless the context clearly dictates otherwise. Also, as used herein, the words "comprise" and / or "comprising" specify the presence of stated shapes, numbers, steps, operations, members, elements, and / or groups thereof, but do not exclude the presence or addition of one or more other shapes, numbers, operations, members, elements, and / or groups.

[0036] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0037] FIG. 1 is a perspective view of a friction shaft for a slitter according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a friction shaft for a slitter according to one embodiment of the present invention, FIG. 3 is a cross-sectional view of a friction shaft for a slitter according to another embodiment of the present invention, FIG. 4 is a perspective view of a rotating shaft and a rotary joint of the friction shaft for a slitter according to one embodiment of the present invention, FIG. 5 is a cross-sectional view taken along line A-A' in FIG. 4, FIG. 6 is a cross-sectional view taken along line B-B' in FIG. 4, FIG. 7 is a perspective view of a lug portion of a friction shaft for a slitter according to one embodiment of the present invention, FIG. 8 is an enlarged view of portion A in FIG. 2, FIGS. 9a and 9b are operation diagrams of a friction shaft for a slitter according to one embodiment of the present invention, FIG. 10 is a perspective view of a rotating shaft according to another embodiment of the present invention, FIG. 11 is a cross-sectional view taken along line C-C' in FIG. 10, and FIG. 12 is a cross-sectional view taken along line D-D' in FIG.

[0038] 1 to 12, a friction shaft according to one embodiment of the present invention has a take-up tube on its outer surface for winding up unit materials formed by cutting raw materials such as various types of paper, fabric, and film at predetermined intervals into rolls. The friction shaft includes a rotating shaft 100, a friction core 200 attached to the rotating shaft 100, a lug portion 300 attached to the friction core 200 for selectively chucking the take-up tube, and a rotary joint 400 connected to one end of the rotating shaft 100.

[0039] On the other hand, the winding tube can be made of a paper tube or an FRP core, or the like.

[0040] The rotary shaft 100 is rotated by a drive motor, and compressed air is supplied from an air supply unit 500 .

[0041] The rotating shaft 100 includes a first main body portion 110, a main flow passage 120, and a sub-flow passage .

[0042] The first main body portion 110 forms the main body of the rotating shaft 100 .

[0043] The main flow passage 120 penetrates the first body portion 110 in the longitudinal direction and is made up of a plurality of passages with different lengths.

[0044] Further, compressed air selectively supplied from an air supply unit 500 moves through the main flow path 120 .

[0045] The sub-channels 130 are provided in a number corresponding to the number of main channels 120, and communicate with the outside of the first body portion 110.

[0046] That is, the sub-flow passage 130 supplies the compressed air supplied from the air supply section 500 to the friction core 200 .

[0047] The friction cores 200 are short-tube shaped, and a plurality of them are attached to the rotary shaft 100 in a line at predetermined intervals along the longitudinal direction.

[0048] Furthermore, a take-up tube is attached to the outer peripheral surface of the friction core 200.

[0049] The friction core 200 includes a second main body portion 210 , a through hole 220 , a seating hole 230 , a roller portion 240 , a retainer support base 250 , and a retainer 260 .

[0050] The second main body portion 210 constitutes the main body of the friction core 200 and has a short pipe shape.

[0051] There are a plurality of through holes 220, which are spaced apart at equal intervals along the circumferential direction of the second main body portion 210.

[0052] Furthermore, the through-hole 220 penetrates the second main body portion 210 in the radial direction, and the lug portion 300 is inserted therein.

[0053] Such through holes 220 allow the outside and inside of the friction core 200 to communicate with each other.

[0054] Furthermore, the through-hole 220 has a T-shape in cross section that converges downward.

[0055] There are multiple seating holes 230, which are formed along the longitudinal direction of the rotation axis 100 of the second main body portion 210 and are spaced apart at equal intervals from each other along the circumferential direction of the second main body portion 210.

[0056] Such seating holes 230 are formed in regions of the second body portion 210 that do not overlap with the plurality of through holes 220 , that is, between the plurality of through holes 220 .

[0057] The roller portions 240 are provided in a plurality to correspond to the seating holes 230, and are seated in the seating holes 230 respectively.

[0058] The outermost surface of the roller portion 240 abuts against the inner peripheral surface of the take up tube.

[0059] That is, the roller portion 240 allows the take up tube to easily move from the friction core 200 without the lug portion 300 chucking the take up tube.

[0060] As a result, when the mounting position of the take-up tube to the friction core 200 is adjusted while the lug portion 300 is not chucking the take-up tube, the roller portion 240 rotates together with the take-up tube, allowing the heavy take-up tube to be easily moved and the position adjusted.

[0061] The retainer support bases 250 are preferably ring-shaped and consist of a pair of rings, each of which is disposed at one end and the other end of the second main body portion 210 .

[0062] Furthermore, the outer peripheral surface of the retainer support base 250 contacts the inner peripheral surface of the second main body portion 210 , and the inner peripheral surface contacts the retainer 260 .

[0063] The retainers 260 are made up of a pair and are arranged on the inner peripheral surface of the retainer support base 250 in the left-right direction of the lug portion 300 .

[0064] The outer circumferential surface of the retainer 260 contacts the inner circumferential surface of the retainer support base 250 , and the inner circumferential surface contacts the outer circumferential surface of the first main body portion 110 .

[0065] The retainer 260 is made of an elastic material such as silicone or urethane, and has grooves formed in opposing directions.

[0066] As a result, when air pressure is injected from the outside, the grooves of retainer 260 are elastically deformed by the air pressure, and the outer surface of retainer 260 presses against the inner surface of retainer support base 250, which in turn presses against the outer surface of first main body portion 110.

[0067] With this structure, the retainer 260 can effectively transmit torque to the friction core 200 when the rotating shaft 100 rotates.

[0068] The plurality of friction cores 200 configured as described above can be made up of a first core 200_1, a second core 200_2, a third core 200_3, and a fourth core 200_4.

[0069] As shown in FIG. 2, the first core 200_1 refers to four of the plurality of friction cores 200 arranged in a first region A1, which is one end where the rotary joint 400 is connected, and the second core 200_2 refers to four of the plurality of friction cores 200 arranged in a second region A2, which is a region adjacent to the first region A1 in the opposite direction from the position where the rotary joint 400 is connected, based on the first region A1.

[0070] Furthermore, the third core 200_3 refers to another four friction cores 200 among the plurality of friction cores 200 arranged in a third region A3, which is a position adjacent to the second region A2 in the region opposite to the position where the rotary joint 400 is connected, with the second region A2 as the reference, and the fourth core 200_4 refers to another four friction cores 200 among the plurality of friction cores 200 arranged in a fourth region A4, which is a position adjacent to the third region A3 in the region opposite to the position where the rotary joint 400 is connected, with the third region A3 as the reference.

[0071] On the other hand, for the sake of convenience, the friction shaft for a slitter of the present invention has been described as being divided into a first region A1 to a fourth region A4. However, as shown in FIG. 3, depending on the usage environment of the present invention, the friction shaft for a slitter of the present invention may be composed of at least a second region or more, i.e., the first region A1 to the nth region An, and thus the friction core 200 can also be composed of a first core 200_1 and a second core 200_2 or the first core 200_1 to the nth core 200_n in a corresponding manner.

[0072] The plurality of friction cores 200, namely the first core 200_1, the second core 200_2, the third core 200_3, and the fourth core 200_4, are fitted into the first main body portion 110 in sequence along the axial direction.

[0073] As a result, the lug portion 300 inserted into the through hole 220 of the second main body portion 210 comes into contact with various positions on the inner peripheral surface of the take up tube, thereby enabling the take up tube to be chucked stably.

[0074] The main channels 120, which are different in length from one another, include a first main channel 121, a second main channel 122, a third main channel 123, and a fourth main channel .

[0075] The first main flow path 121 penetrates from one end of the first main body portion 110 where the rotary joint 400 is connected to the first region A1, and the second main flow path 122 does not overlap with the first main flow path 121 in the first main body portion 110 and penetrates from one end of the first main body portion 110 where the rotary joint 400 is connected to the second region A2.

[0076] In addition, the third main flow path 123 does not overlap with the first main flow path 121 or the second main flow path 122 in the first main body portion 110, and passes through from one end where the rotary joint 400 is connected to the third region A3, and the fourth main flow path 124 does not overlap with the first main flow path 121 to the third main flow path 123, and passes through from one end where the rotary joint 400 is connected to the fourth region A4.

[0077] In addition, the sub-channel 130 formed at the end of the main channel 120 consists of a first sub-channel 131, a second sub-channel 132, a third sub-channel 133, and a fourth sub-channel 134, depending on the formation positions of the first main channel 121 to the fourth main channel 124.

[0078] The first sub-channel 131 is formed in a first region A1 of the first main channel 121 that penetrates to the first region A1, and the second sub-channel 132 is formed in a second region A2 of the second main channel 122 that penetrates to the second region A2.

[0079] In addition, the third sub-channel 133 is formed in the third region A3 of the third main channel 123 that penetrates to the third region A3, and the fourth sub-channel 134 is formed in the fourth region A4 of the fourth main channel 124 that penetrates to the fourth region A4.

[0080] These sub-flow passages 130 are formed at positions corresponding to the respective friction cores 200 .

[0081] That is, the present invention can supply compressed air at different pressures through a plurality of main flow paths 120 and sub-flow paths 130 .

[0082] Therefore, compressed air of different pressures is supplied to each of the friction cores 200 inserted in the first area A1 to the fourth area A4 through the multiple main flow paths 120 and sub-flow paths 130, and torque generated by the air pressure is applied to each of the multiple friction cores 200.

[0083] That is, it is possible to reduce variations in torque that occur due to various causes such as assembly tolerances between components that make up the friction shaft, surface roughness, heat generated during product operation, wear, and clogging with foreign matter.

[0084] This allows a constant torque to be generated in each friction core to which the take-up tube is attached, making it possible to stably wind the fabric onto the take-up tube.

[0085] Furthermore, the present invention can be made versatile according to the usage environment by supplying compressed air of different pressures to the first core 200_1 to the fourth core 200_4, or by supplying compressed air only to necessary areas of the first core 200_1 to the fourth core 200_4, thereby reducing variations in torque applied to the multiple friction cores 200.

[0086] The lug portions 300 chuck the take up tube, and are attached to the friction core 200 so as to be slidable in the radial direction, with a plurality of lug portions 300 spaced apart at equal intervals along the circumferential direction of the rotary shaft 100 .

[0087] Specifically, the lug portions 300 are inserted into a plurality of through holes 220 formed in the second body portion 210 along the circumferential direction thereof.

[0088] That is, the lug portion 300 is inserted into the through-hole 220 that penetrates the outer peripheral surface and the inner peripheral surface of the second main body portion 210, and thereby moves slidably along the compressed air supplied from the sub-flow passage .

[0089] The lug portion 300 includes an upper lug 310 , a connecting portion 320 , a lower lug 330 , and an elastic member 340 .

[0090] The upper surface of the upper lug 310 is exposed to the outside, and when compressed air flows in from the air supply part 500, the upper surface comes into contact with the inner peripheral surface of the take up tube.

[0091] That is, the upper lug 310 chucks the take up tube when compressed air flows into it.

[0092] The connecting portion 320 extends downward from the lower surface of the upper lug 310 and is formed with a width shorter than the width of the rotating shaft 100 in the longitudinal direction.

[0093] The lower lug 330 extends from the lower end of the connecting portion 320 to both ends in the circumferential direction of the rotary shaft 100, and has seats 331 formed on both upper surfaces thereof with the connecting portion 320 at the center.

[0094] That is, the lower lug 330 is shielded by the second body portion 210 .

[0095] Therefore, when the lower lug 330 is pressed through the sub-passage 130, it is possible to effectively prevent the lower lug 330 from being removed from the through-hole to the outside.

[0096] The resilient member 340 is preferably a compression spring and seats on the seat 331 of the lug portion 300 .

[0097] Furthermore, the elastic member 340 allows the lug portion 300 to return toward the rotation axis 100 when the supply of air pressure to the sub-flow passage 130 is stopped.

[0098] For this reason, one end of the elastic member 340 is seated on the seating portion 331 and the other end is in contact with the inner circumferential surface of the second main body portion 210 .

[0099] As a result, the elastic member 340 elastically supports the lower lug 330, allowing the lug portion 300 to elastically return toward the rotation axis 100 when the supply of air pressure to the sub-flow path 130 is stopped.

[0100] The rotary joint 400 engages with either one of the ends of the rotary shaft 100 and supplies air supplied from the air supply unit 500 to the main flow path of the rotary shaft 100.

[0101] Such a rotary joint 400 includes a third main body portion 410 , a first communication hole 420 , a second communication hole 430 , a third communication hole 440 , and a fourth communication hole 450 .

[0102] The third body portion 410 forms the main body of the rotary joint 400 .

[0103] The first communication hole 420 penetrates between one end and the other end of the third main body portion 410 and communicates with the first main flow path 121, and the second communication hole 430 penetrates between one end and the other end of an area of ​​the third main body portion 410 that does not overlap with the first communication hole 420 and communicates with the second main flow path 122.

[0104] In addition, the third communication hole 440 penetrates one end and the other end of the area in the third main body portion 410 that does not overlap with the first communication hole 420 and the second communication hole 430, and is connected to the third main flow path 123, and the fourth communication hole 450 penetrates one end and the other end of the area in the third main body portion 410 that does not overlap with the first communication hole 420 to the third communication hole 440, and is connected to the fourth main flow path 124.

[0105] To the first through fourth communication holes 420 to 450, connection pipes through which compressed air is supplied from the air supply section 500 are connected, respectively.

[0106] Therefore, compressed air with different pressures can be supplied to the first communication hole 420 to the fourth communication hole 450 from the air supply section 500 as required.

[0107] Therefore, the first communication hole 420 to the fourth communication hole 450 can effectively reduce the variation in the torque applied to the first core 200_1 to the fourth core 200_4 in the first region A1 to the fourth region A4 by supplying compressed air of different pressures to the multiple main flow paths 120 and sub-flow paths 130, respectively.

[0108] For example, when the torque of the second core 200_2 of the first core 200_1 to the fourth core 200_4 is low, a larger air pressure is selectively supplied to the second core 200_2 than to the other cores 200_1, 200_3, and 200_4, thereby generating a larger torque than that of the retainer 260 of the second core 200_2, and when the torque of the fourth core 200_4 of the first core 200_1 to the fourth core 200_4 is high, a smaller air pressure is selectively supplied to the fourth core 200_4 than to the other cores 200_1, 200_2, and 200_3, thereby generating a smaller torque than that of the retainer 260 of the fourth core 200_4.

[0109] This makes it possible to reduce variations in torque among the first core 200 to the fourth core 200_4 arranged in the first region A1 to the fourth region A4.

[0110] Meanwhile, the rotating shaft 100 according to another embodiment of the present invention may further include a groove 140 .

[0111] The recesses 140 are made up of a plurality of recesses, which are formed on the outer peripheral surface of the first main body portion 110 along the longitudinal direction of the rotary shaft 100, and communicate with the plurality of sub-flow paths 130, respectively.

[0112] Specifically, the recesses 140 are formed in the first sub-channel 131, the second sub-channel 132, the third channel 133, and the fourth channel 134, respectively.

[0113] This allows the recesses 140 to supply compressed air at a uniform pressure to the lug portions 300 inserted into the four friction cores 200 that make up the first core 200, for example.

[0114] As stated above, the embodiments disclosed herein should be considered as illustrative and exemplary, not restrictive. The scope of the present invention is defined by the claims, not the foregoing description, and all differences within the scope of the claims should be construed as belonging to the present invention.

Claims

1. A friction shaft for a slitter, the shaft having a winding tube on its outer surface for winding unit materials formed by cutting raw materials including various types of paper, fabrics, or films at predetermined intervals into rolls, a rotating shaft that is rotated by a drive motor and to which compressed air is supplied from an air supply unit; a plurality of friction cores each having a short tube shape and attached to the rotary shaft in a line; a plurality of lug portions attached to the friction core and spaced apart at equal intervals along the axial direction of the rotary shaft; a rotary joint connected to an end of the rotary shaft and supplying air from an air supply unit to the rotary shaft; The rotation axis is a first main body portion constituting a main body; a plurality of main flow paths that extend through the first main body portion in a longitudinal direction and have different lengths; a plurality of sub-flow passages that connect the plurality of main flow passages to the outside of the first body portion;

2. The friction core is a second body portion forming a main body; an insertion hole that radially penetrates the second body portion and into which the lug portion is inserted; a plurality of seating holes spaced apart at equal intervals along the circumferential direction of the rotary shaft in the second main body portion at positions not overlapping with the through hole; 2. The friction shaft for a slitter according to claim 1, further comprising: a plurality of roller portions seated in the seating holes.

3. The friction core is a retainer support base attached to the rotary shaft; 3. The friction shaft for a slitter according to claim 2, further comprising a retainer supported by the retainer support base and generating torque by air pressure introduced from the outside.

4. The plurality of friction cores are four first cores arranged in a first region that is one end to which the rotary joint is connected; four second cores arranged in a second region, the second region being adjacent to the first region and located in a region opposite to a position where the rotary joint is coupled relative to the first region; four third cores arranged in a third region, which is a region adjacent to the second region and located in an opposite direction from a position where the rotary joint is coupled with respect to the second region; and and four fourth cores arranged in a fourth region, which is a region adjacent to the third region and in a region opposite to the position where the rotary joint is connected with respect to the third region.

5. 4. The friction shaft for a slitter according to claim 3, wherein the plurality of friction cores are attached to the first body portion in sequence.

6. The main flow path is a first main flow path extending from one end to which the rotary joint is connected to a first region; a second main flow path that does not overlap with the first main flow path and penetrates from one end to which the rotary joint is connected to a second region; a third main flow path that does not overlap the first main flow path and the second main flow path and penetrates from one end to which the rotary joint is coupled to a third region; a fourth main flow path that does not overlap with the first to third main flow paths and penetrates from one end to a fourth region where the rotary joint is coupled.

7. The sub-channel is a first sub-channel formed in a first region of the first main channel; a second sub-channel formed in a second region of the second main channel; a third sub-channel formed in a third region of the third main channel; 7. The friction shaft for a slitter according to claim 6, further comprising: a fourth sub-flow passage formed in a fourth region of the fourth main flow passage.

8. The rotation axis is The friction shaft for a slitter according to claim 7, further comprising a plurality of grooves formed on an outer circumferential surface of the first body portion along a longitudinal direction thereof and communicating with the sub-flow passages.

9. 9. The friction shaft for a slitter according to claim 8, wherein the recesses are formed in the first sub-flow path, the second sub-flow path, the third sub-flow path, and the fourth sub-flow path, respectively.

10. The lug portion is an upper lug whose upper surface comes into contact with the inner peripheral surface of the winding tube when compressed air flows in from the air supply section, thereby chucking the winding tube; a connecting portion extending downward from the lower surface of the upper lug; a lower lug having a seat formed on its upper surface and extending from a lower end of the coupling portion to both ends in the circumferential direction of the rotating shaft; 4. The friction shaft for a slitter according to claim 3, further comprising: an elastic member having one end seated on said seat portion and the other end in contact with the inner circumferential surface of said second main body portion.

11. 11. The friction shaft for a slitter according to claim 10, wherein the elastic member is a compression spring.

12. The rotary joint is a third body portion forming a main body; a first communication hole that penetrates one end and the other end of the third body portion and communicates with the first main flow path; a second communication hole that penetrates one end and the other end of the third body portion and communicates with the second main flow path; a third communication hole that penetrates one end and the other end of the third body portion and communicates with the third main flow path; 7. The friction shaft for a slitter according to claim 6, further comprising: a fourth communication hole that penetrates one end and the other end of the third body portion and communicates with the fourth main flow path.

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