JPH07285184A - Square paper pipe and production thereof - Google Patents

Abstract

PURPOSE:To obtain a square paper pipe free from a twist or warpage and having extremely high quality and high strength. CONSTITUTION:The first - third strip like papers 31-33 successively supplied in the axial direction of a square shaft 27 to be laterally folded in succession so that four surfaces forming a square are formed by molding devices 82a-82c and a plurality of the first - third strip like papers 31-33 thus molded are laminated so that the abutted parts thereof become an alternately symmetric position at every layers and two fourth strip like papers 34 supplied in two opposed directions are laterally bent and molded so that two adjacent surfaces are formed by a molding device 82d. Thereafter, the strip like papers 31-34 are axially sent while held and pressed by four rollers 22 provided in opposed relation to the side surfaces of the square shaft 27 to form an outer layer. Since the strip like papers are pressed through the outer layer composed of two fourth strip like papers 34 having the same V-shape cross section, they are uniformly pressed as a whole and a high strength square paper pipe free from a twist or warpage is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a square paper tube and a method for manufacturing the same, and more specifically, it shows a rectangular cross-section manufactured by pressing a strip-shaped paper on a shaft having a square cross-section in the axial direction of the shaft. The present invention relates to a paper tube having a mold, and a method for manufacturing the paper tube.

[0002]

2. Description of the Related Art Heretofore, a square paper tube has been known which is manufactured by bending a paperboard to form a ridge and a surface and connecting the edges together. However, this square paper tube
Not only is the strength of the joints extremely weaker than other parts, but also sufficient strength cannot be obtained due to strain on the outer surface due to bending of the thick paperboard and compression on the inner surface, so building materials such as columns and beams. As a structural material, it could not be used.

Therefore, as a means for solving such a problem, a plurality of strips of paper are formed in a width direction so that two or three surfaces are formed along the axial direction of a square shaft serving as a core metal. Some of them are manufactured by bending them, sequentially shifting them so that they overlap each other on at least one surface, and sequentially stacking them linearly in the axial direction, followed by crimping (Japanese Patent Publication No. 59-15).
92 publication).

Since the square paper tube manufactured in this manner is constructed by laminating a plurality of strips of paper, almost no distortion occurs on the outer surface and the inner surface, and it is joined at one ridge. Since there are no special points, the strength increases.

[0005]

By the way, since the conventional rectangular paper tube is constructed by bending a plurality of strip-shaped papers in the width direction and stacking them so as to overlap each other on at least one surface, The cross-sectional shape of the pattern tube is such that the respective band-shaped papers are out of phase by the same amount in the circumferential direction, and the strength after manufacturing is substantially uniform at each position of the cross-section.

However, in the case of manufacturing the above-mentioned conventional rectangular paper tube, since the belt-shaped papers are sequentially laminated while being shifted in a certain direction and adhered to each other, the outermost belt-shaped paper is a square-shaped paper. Of the four surfaces that make up, for example, any 2
It is configured to cover one side or three sides. Therefore, the pressing force finally applied by the roller or the like is not uniformly applied to the whole of the belt-shaped papers already laminated. For this reason, the adhesive for adhering the strip-shaped papers to each other is pressed by the roller or the like in a state where it is not completely dried, and there is a problem that the fed rectangular paper tube is twisted or warped. It was

In particular, recently, there has been a method of use in which a plurality of rectangular paper tubes are arranged in parallel between two boards arranged in parallel, and these are joined together. If the pattern paper tube is twisted or warped, a gap or rattling will occur between the rectangular paper tube and the board, and not only tight bonding will be possible but also the board may be bent if forcibly bonded. . Moreover, the strength was not always satisfactory.

Further, a so-called spiral type square paper tube constituted by winding a strip-shaped paper in an oblique direction while rotating a square shaft serving as a core bar has been conventionally known. Not suitable for intended use. That is, since the direction of the fibers of the band-shaped paper is usually the longitudinal direction and it has the property of expanding and contracting in the direction orthogonal to the fiber direction, that is, the width direction of the band-shaped paper due to moisture, this band-shaped paper is wound diagonally. This is because the formed rectangular paper tube tends to cause twisting.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to obtain an extremely high-quality rectangular paper tube which is free from twisting and warping. It is in.

[0010]

In order to achieve the above object, the present invention provides a rectangular paper formed by bending a plurality of strips of paper in the width direction of the strips, stacking them, and pressing them while feeding them in the longitudinal direction. In the tube, a plurality of strip-shaped papers folded in the width direction so that four square surfaces are formed are laminated so that the abutting portions are at different positions for each layer, and two adjacent surfaces are stacked. The rectangular paper tube is characterized in that the outer layer is formed by press-bonding two strips of paper that are folded in the width direction so that they are formed so as to face each other in two directions.

Further, in the case of manufacturing the square paper tube, a plurality of strips of paper are sequentially bent in the width direction along a square shaft serving as a core bar to be laminated and fed in the axial direction of the square shaft. In a method for manufacturing a rectangular paper tube formed by pressure bonding, a molding machine provided so as to surround the rectangular shaft so that a band-shaped paper sequentially supplied in the axial direction of the rectangular shaft is formed with a predetermined gap. Are sequentially bent in the width direction so as to form four rectangular surfaces, and a plurality of band-shaped papers thus formed are laminated so that the abutting portions are at different positions for each layer, Two strips of paper supplied from two directions toward the opposite edges of the mold shaft,
The rectangular shaft is bent and molded in a width direction so that two adjacent surfaces are formed by a molding machine surrounding the rectangular shaft so as to form a predetermined gap, and then the rectangular shaft is penetrated through the center. By moving the axial direction while sandwiching and pressing the strip-shaped paper between the four rollers provided on one surface of the fixed support plate facing the side surface of the square shaft and the square shaft, It may be manufactured by a method for manufacturing a rectangular paper tube characterized by forming an outer layer. Further, it is preferable that the four corners of the rectangular shaft are formed into a predetermined chamfered shape or an R shape.

[0012]

According to the present invention having such a structure, the strip-shaped paper sequentially supplied in the axial direction of the square shaft is inserted into a predetermined gap between the square shaft of the molding machine and the square shaft. Are bent in the width direction so that four surfaces are formed. Next, the band-shaped papers thus formed are laminated so that the butted portions are located at different positions for each layer. Then, two strips of paper are supplied so as to face each other, are bent and formed in the width direction so that two adjacent surfaces are formed, and then are provided so as to face the side surface of the square shaft. The strip-shaped paper is sandwiched between the individual rollers and the square shaft, and is pressed and fed in the axial direction.

As described above, not only the paper tube having a rectangular cross-section which is sequentially laminated linearly in the axial direction and press-bonded can be manufactured simply and continuously, but the inner layer from the outer layer is formed by bending one strip of paper. In addition to being configured so that four rectangular surfaces are formed and the abutting portions are sequentially laminated so as to be at different positions in each layer, extremely uniform and strong manufacturing is performed.

Moreover, since the outer layer is composed of two second strip-shaped papers having the same shape and facing each other, the pressing force applied by the roller is uniformly applied to all the layers already laminated, and therefore Since the layers are pressed against each other uniformly, twisting and warping are prevented.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a schematic configuration of an apparatus for manufacturing a square paper tube according to an embodiment of the present invention. As shown in FIG. 1, the apparatus for manufacturing the square paper tube of the present embodiment (hereinafter referred to as the present apparatus) includes a first molding section 62, a second molding section 64,
The first crimping portion 65, the third molding portion 67, the fourth molding portion 70, the second crimping portion 71, and the cut portion 72 are provided, and the belt-shaped paper is arranged in the axial direction of the square shaft 27 serving as a core metal. This is a so-called linear type square-shaped paper tube manufacturing apparatus in which layers are sequentially laminated linearly and pressure-bonded.

On the upstream side of the first molding section 62, a first supply section 61 is provided as shown in the figure. This first supply unit 61
Has a first base paper roll 72, and
Is set in a rolled state. The first band-shaped paper 31 has a width that covers four surfaces around the square shaft 27, and, for example, in the case of a square paper tube having an outside dimension of 45 mm square (inside dimension 40 mm), has a width of 162 mm. Since the first strip paper 31 supplied from the first raw paper roll 72 constitutes the innermost layer of the square paper tube, no adhesive is applied, and paraffin is applied to the inner side of the roller 73 that contacts the square shaft 27. Is applied. This is to improve the sliding of the formed rectangular paper tube so that it is fed in the axial direction to proceed. The first strip-shaped paper 31 coated with paraffin is fed from below toward the square shaft 27 while being guided by a plurality of guide rollers 74 arranged at predetermined positions.

A bending roller 75a is installed at a position where the first belt-shaped paper 31 supplied from the first supply section 61 reaches the rectangular shaft 27. The folding roller 75a is
As shown in FIG. 2, it is rotatably supported by a shaft 76 via a bearing 77. The folding roller 75a has a V
The character-shaped groove 106 is provided, and a predetermined gap 78 is formed between the character-shaped groove 106 and the square shaft 27. The supplied first strip-shaped paper 31 is allowed to pass through the gap 78 and bent into a V shape.

3A is a side view showing the first molding portion 62, FIG. 3B is a sectional view taken along the line QQ, and FIG. 3C is a partial plan view. The first forming section 62 is provided on the downstream side adjacent to the folding roller 75a and has a base paper guide 80.
And an insertion guide 81 and a first molding device 82a.
The base paper guide 80 has a U-shaped groove portion 80a as shown in the drawing, and is configured so that the widthwise edge of the first strip 31 passes through the groove portion 80a and is fed. Thereby, meandering of the edge of the supplied first strip 31 can be prevented. The insertion guide 81 is installed on the immediate upstream side of the first molding device 82a, but has two guide plates 83 and 84, and caps the lower mold 86 of the first molding device 82a described later with the wing bolt 87. It is attached to a square rod 98 fixed by a screw 108 (see FIG. 4). As shown in FIG. 3C, the guide plates 83 and 84 are formed such that the upstream inlet portions 83a and 84a have a small plate thickness, which increases the gap between the guide shafts 83 and 84a and the square shaft 27. The one strip 31 is easily guided to this insertion guide 81. On the other hand, the guide plates 83 and 84 are gradually increased in thickness toward the outlets 83b and 84b on the downstream side, and the first strip 31 extends along the four side surfaces of the square shaft 27. Shaped into a shape.

The first molding device 82a includes an upper mold 85 and a lower mold 86.
And a square bar 98 fixed to the end of the lower die 86.
The upper mold 85 and the upper mold 85 are tightened with butterfly bolts 87. As a result, a predetermined gap 88a is formed between the square shaft 27 and the first belt-shaped paper 31 fed through the base paper guide 80 and the insertion guide 81 is inserted into the gap 88a and passes therethrough, As shown in FIG. 4, the first layer a is molded as a result of being bent in the width direction so that four square surfaces are formed. The first
The width of the band-shaped paper 31 is dimensioned so that a slight predetermined gap is formed in the butted portion 89a that is bent in the width direction, and is configured not to be stretched at the butted portion 89a. Further, the four corners 27a of the square shaft 27 are formed in a predetermined R shape of R2 to R3, for example, and the bent portion of the first strip 31 has a shape substantially following the R shape. The corner 97a does not protrude outside the quadrangular shape. The four corners 27a of the square shaft 27 are not limited to the R shape, but may be linear chamfered shapes.

In the lower part of the lower die 86 of the first molding device 82a,
The support rods 90, 90 are attached by welding, and are supported on the upper surface of the spherical bearing 92 via a spring member 91. Further, the spherical bearing 92 is arranged at the center of the bearing cover 93 of the spherical bearing 92, and the bearing cover 93
A shaft 94 attached to the side surface of the is fixed and supported by a pillow block 95. Therefore, the first molding device 82a is installed with a predetermined degree of freedom in the direction orthogonal to the axial direction of the square shaft 27. A male screw is formed at the tip of each of the support rods 90, 90 so that the nut 96 can adjust the height to some extent.

As shown in FIG. 1, a second molding section 64 is provided on the downstream side of the first molding section 62, and a second supply section 63 is provided on the upstream side thereof. From the second supply section 63, the second strip-shaped paper 32 (width dimension 166 mm; first supply section 6)
(The width is 4 mm larger than the first strip 31 used in No. 1), but since it constitutes the second layer from the inside, the adhesive is applied to the lower surface side in the figure by the roller 55a. . Polyvinyl acetate-based adhesives are usually used as this adhesive, but urea resin-based adhesives, phenolic resin-based adhesives, or glue can be used to enhance the strength of the product or for adherends other than paper. Used.

The molding unit 82b of the second molding unit 64 has a shape in which the upper mold and the lower mold of the first molding unit 62 are reversed, but has substantially the same configuration and has a predetermined shape. Gap 8
8b is formed (see FIG. 5). The second strip-shaped paper 32, which is supplied from above from the second supply section 63 toward the square shaft 27, is bent into a V shape by the folding roller 75b, and is then square-shaped by the second molding section 64. As a result of being bent in the width direction so as to form four surfaces, the second layer b is formed as shown in FIG. In this way, the first layer a and the second layer b are layered so as to overlap each other on the four surfaces, and the abutting portions 89a and 89a of the respective layers are joined together.
Since 9b is arranged in a symmetrical position, it is uniform and strong.

The first crimping portion 65 is provided on the downstream side adjacent to the second molding portion 64. FIG. 6 shows the first crimp portion 65.
Is a side view, FIG. 7 is an enlarged cross-sectional view of the main part, and FIG.
6 is a cross-sectional view taken along the line RR of FIG. 6, FIG. 9 is a cross-sectional view showing a power transmission mechanism for the roller, FIG. 10 is a cross-sectional view showing a mounting state of the roller, and FIG. 11 is a roller showing manufacturing of a rectangular paper tube. It is sectional drawing which shows the position of.

As shown in FIGS. 6 and 7, the fixed support plate 2 having the cavity 1 in the center thereof is arranged coaxially with the hollow tube 3 and fixed to the hollow tube 3. For example, the fixed support plate 2 is coupled to the flange portion 4 of the hollow tube 3 with a bolt 5. The hollow tube 3 is held by a block 7 provided on a frame 6. The hollow tube 3 is provided with a bearing 8 between the fixed support plate 2 and the block 7, which are continuously provided at one end of the hollow tube 3. Further, the bearing 8 has a parallel shaft gear device 9 for branching a rotary system. Is provided. That is, the drive gear 10 of the parallel shaft gear device 9 is provided coaxially with the hollow tube 3 and is rotatably supported by the bearing 8. A desired number of driven gears 11, usually four, are provided around the drive gear 10. And
As shown in FIG. 7, the driven gear 11 is attached to one end of a rotatable shaft 13 that penetrates the fixed support plate 2 through the holes 12 provided in the number.
The driven gear 11 is rotated about the axis by the power transmitted from the drive gear 10. On the other hand, the parallel shaft gear device 9 is provided with transmission means 14 such as gears and pulleys via a collar, if necessary. This transmission means 1
4 is locked to the drive gear 10 of the parallel shaft gear device 9 with bolts 15 and the like. And this transmission means 14
It is connected to the power source. In this device, the power of the variable speed motor 16 of the second crimping portion 71 described later is branched and transmitted by the transmission shaft 107. For example, the sprocket 14 in FIGS. 6 and 7 is decelerated from the sprocket 17 via the chain 18. The generated power is transmitted. In addition,
This power transmission mechanism does not necessarily have to be as described above, and deceleration can be transmitted from the motor shaft using any means such as a gear, a sprocket, and a pulley.

The shaft 13 rotatably pierced through the hole 12 of the fixed support plate 2 is held by a bearing 19 provided on the fixed support plate 2, as shown in FIGS. Is a transmission means 20 such as a bevel gear.
Is provided. The other end of the bevel gear 21, which is in contact with the bevel gear 20, is connected to a roller 22 provided on the fixed support plate 2 via a universal joint 43. The rollers 22 are provided in the same number as the driven gears 11, and are normally held by the bracket 23.

The hollow portion 1 has a square shaft 2 whose one end is held by a stand 25 provided on a frame 24.
7 (see FIG. 1) is penetrated, and the other end is the roller 2
Held by two.

Next, a mechanism for transmitting the power transmitted from the bevel gear 20 of the first crimping portion 65 to the roller 22 will be described. As shown in FIG. 9, the shaft 13 of the bevel gear 20
Are pierced through holes 12 provided in the fixed support plate 2 and supported by bearings 19 and 19 ′ provided on both sides of the support plate 2. A bearing 34 is further accommodated at the tip of a casing 33 that accommodates the bearing 19 ′, and an end portion 36 of a bracket 35 is fitted and inserted. At the upper part of the end portion 36,
The bracket 35 is locked to a stopper 38 provided near the tip of the casing 33 with a screw 37 or the like.
The stopper 38 is rotatably provided with respect to the casing 33, and is tightened with a screw 39 after adjusting the direction. The shaft 13 passes through a hole provided at the bottom of the bracket 35, and the bevel gear 2 is provided at the tip thereof.
0 is fixed. Bearings 40 and 41 are provided on both sides of the bracket 35, and support a shaft 42. Another bevel gear 21 is fitted into the shaft 42 and meshes with the bevel gear 20. The tip of the shaft 42 penetrates the side of the bracket 35, and is further connected to the shaft of the roller 22 via a universal joint 43.

As shown in FIGS. 9 and 10, a base plate 45 is provided on the fixed support plate 2 with pins 44.
On the shaft 5, a shaft 46 having a bracket 23 is further provided.
Is provided, and the shaft 46 is held by a stand 47. A bearing 48 is provided on the bracket 23,
A spline shaft 49 provided on the shaft of the roller 22 is fitted and inserted. The bracket 23 is supported by a shaft 46 at its bottom. Further, the back surface of the bracket 23 is supported by a holding member 51 provided with a cushioning material 50 such as rubber if necessary. Like the stand 47, the holding member 51 has its angle adjusted by a screw 53 screwed to a stand 52 provided on the same pedestal 45, and the position of the roller is also adjusted by this adjustment. That is, since the roller 22 is constantly pressed by the action of the screw 53, as shown in FIG. 11, the layers a and b of the first belt-shaped paper 31 are sandwiched between the shaft 27 and each other. It is configured to be formed into a square shape by being crimped. The surface of the roller 22 has a sufficient force to feed the belt-shaped paper, so that the knurled groove 2
2a is provided.

As shown in FIG. 1, a third molding portion 67 is provided on the downstream side adjacent to the first crimp portion 65, and a third supply portion 66 is provided below the third molding portion 67. Third supply unit 66
The third belt-shaped paper 33 (width dimension 171 mm; width is 5 mm larger than the second belt-shaped paper 32) is supplied from the roller 55.
The adhesive is applied to the surface by b. This third molding part 6
7 has a configuration similar to that of the first molding portion 62,
As shown in FIG. 12, the molding device 82c forms a predetermined gap 88c. The third belt-shaped paper 33 supplied from below from the third supply unit 66 toward the square shaft 27.
Is bent in a V shape by the bending roller 75c, and then bent in the width direction so that four square surfaces are formed by the third forming portion 67, and as a result, as shown in the drawing, Three layers c are molded. In this way, the first layer a, the second layer b, and the third layer c are layered so that the four surfaces overlap each other, and the respective butting portions 89 are formed.
The a, 89b, and 89c are arranged so as to be alternately symmetrical positions.

Further, in the present apparatus, a fourth molding section 70 is provided on the downstream side of the third molding section 67, a fourth supply section 68 is located below the fourth molding section 70, and a fifth supply section 69 is located upstream thereof. It is provided. The fourth strip-shaped paper 34 is configured to be supplied from the respective supply units 68 and 69, and the fourth strip-shaped paper 34 is provided on the square shaft 27.
The width of the layer c is slightly smaller than the width covering the two outer surfaces of the layer c, and the width of the device is 87 mm. Then, the rollers 55c, 55d are provided on the surface side of the fourth belt-shaped paper 34 facing the square shaft 27 in the drawing.
By this, an adhesive is applied.

The molding device 82d of the fourth molding portion 70 is shown in FIG.
As shown in FIG. 3, it has an upper mold 99 and a lower mold 100,
A predetermined gap 88d is formed by these joining.
The fourth belt-shaped paper 34 supplied from below from the fourth supply unit 68 toward the square shaft 27 is a folding roller 75d.
While being bent into a V shape by the
Fourth supplied from above toward the square shaft 27 from
The band-shaped paper 34 is bent into a V shape by the folding roller 75e. As described above, the fourth band-shaped paper 34 folded in the width direction so as to form two V-shaped surfaces is combined by the fourth forming unit 70 from the vertical direction toward the square shaft 27, As shown in FIG. 13, the fourth layers d and d'are formed. Thus, the first layer a, the second layer b, the third layer c, and the fourth layers d and d ′ are layered so that they overlap each other in the plane. A slight predetermined gap may be formed in the abutting portions 89d and 89d of the fourth layers d and d '.

A second pressure-bonding portion 71 is provided on the downstream side of the fourth molding portion 70. The second crimping portion 71 has substantially the same structure as the first crimping portion 65,
Since the strip-shaped paper sent to the pressure-bonding section 71 has a thickness of the first layer a to the fourth layer d, the setting position of the roller differs depending on the adjustment of the screw 53. As described above, the single variable speed motor 16 provided in the second crimp portion 71 is configured to transmit power to both the first and second crimp portions 65 and 71.

In particular, in this embodiment, the outer layers of the fourth layers d and d ′ are bent in a V-shaped cross section and have the same shape.
Since it is composed of the fourth strip of paper 34, as described above, when it is uniformly pressed by the roller 22 of the second pressure-bonding portion 71 from the opposite direction, the pressing force applied is already laminated. It will be added evenly to the whole of each strip of paper. Therefore, the layers are pressed against each other uniformly,
Twisting and warpage are effectively prevented.

The cutting section 72 is located at the most downstream side in this apparatus.
Is provided. The rectangular paper tube 30 made of laminated band-shaped paper which is sandwiched and pressed by the second pressure bonding portion 71 and is fed in the axial direction is cut into a predetermined length at the cutting portion 72 by, for example, a disc saw.

Next, the method of manufacturing the rectangular paper tube according to the present invention will be described while explaining the operation of the present apparatus configured as described above. First, the desired size and shape, eg 40
The square shaft 27 having a square cross section of mm square is
The crimp portion 65 and the second crimp portion 71 are inserted into the cavity 1 and one end thereof is attached and fixed to the stand 25. Then, according to the size and shape of the shaft 27, each crimping portion 65,
71 the pin 44 is adjusted and the pedestal 45 is rotated to rotate the roller 22.
At the same time that the direction of is determined, the rollers 22 are held at intervals of the desired thickness of the band-shaped paper. With such an adjustment, the direction of the bracket 35 holding the bevel gears 20 and 21 connected to the spline shaft 49 by the universal joint 43 changes at the stopper 38.

On the other hand, the power of the variable speed motor 16 is transmitted to the parallel shaft gear unit 9 via the sprocket 17, the chain 18 and the sprocket 14, and after being branched there, the bevel gears 20 and 21 are rotated by the rotation of the driven gear 11.
Is transmitted to each roller 22 via.

The first strip-shaped paper 31 constituting the innermost layer, which is supplied from the first supply section 61, is coated with paraffin by the roller 73 without applying an adhesive, and the first molding section 6 is applied from below.
Sent to 2. The first band-shaped paper 31 may be composed of, for example, glass fiber or carbon fiber, although other band-shaped papers described later are the same. This first strip 3
1 is inserted into a predetermined gap 88a between the first molding device 82a of the first molding portion 62 and the rectangular shaft 27, and four rectangular surfaces are formed as shown in FIG. As a result of being bent in the width direction, the abutting portion 89a is moved upward.
The first layer a having is formed. Here, since the four corner portions 27a of the square shaft 27 are formed in a predetermined R shape, the corner portion 9 is formed at the bent portion of the first belt-shaped paper 31.
7a does not protrude outside the quadrangular shape, and the layers after the second layer, which will be described later, are closely stacked.

Next, from the second supply section 63 to the second strip 3
2 is supplied, an adhesive is applied by the roller 55a, and the adhesive is sent to the second molding unit 64 from above. This second strip 32
Is inserted into a predetermined gap 88b of the second molding portion 64, and is bent in the width direction so as to form four rectangular surfaces as shown in FIG. The second layer b having is formed.

The paper tube composed of the first layer a and the second layer b on the square shaft 27 thus constructed is introduced into the first pressure-bonding section 65. Then, the paper tube is pressed forward by the roller 22 rotating on its surface and pressure-bonded to be sent forward. This is especially true for roller 22
Shallow and narrow groove 22a carved by knurling on the surface of
Becomes more noticeable.

Furthermore, from the third supply section 66 to the third strip 3
3 is supplied and after applying the adhesive by the roller 55b, it is inserted into a predetermined gap 88c of the third molding portion 67, and as shown in FIG. 12, a third layer c having an abutting portion 89c above is molded. To be done.

Next, the fourth supply section 68 and the fifth supply section 6
9 to the fourth strip 34 are respectively supplied, and the rollers 55
After applying the adhesive with c and 55d, the fourth molding part 7
It is inserted into a predetermined gap 88d of 0. Then, as shown in FIG. 13, the fourth layers d and d ′ are molded as a result of being fitted toward the square shaft 27 from the vertical direction.

In this way, the first layer a, the second layer b, the third layer c, and the fourth layers d and d ′ are layered so that they are superposed on each other, and are introduced into the second pressure-bonding portion 71. The four-layer paper tube is uniformly pressed by the roller 22 of the second pressure-bonding portion 71 from the opposite direction, but the fourth layer d, which is an outer layer,
Since d'is composed of two fourth strips 34 of the same shape bent in a V-shaped cross section, the pressing force applied is evenly applied to all the layers already stacked. Become. Therefore, since the layers are pressed against each other uniformly, it is possible to prevent twisting and warpage. Next, the square paper tube 3 sent from the second pressure bonding unit 71.
0 is cut into a predetermined length by the cutting unit 72.

FIG. 14 is a perspective view showing a square paper tube 30 manufactured by this apparatus. The first layer a to the third layer c of the rectangular paper tube 30 are formed by bending one strip of paper, and are layered so as to overlap each other on four surfaces, and the abutting portions 89a and 89b thereof are respectively formed. , 89c are alternately laminated at symmetrical positions, so that they are uniform and strong. Moreover, since the fourth layers d and d ′ serving as the outer layers are composed of two fourth strip-shaped papers 34 of the same shape bent in a V-shaped cross section, they are opposed to each other by the roller 22 of the second pressure-bonding portion 71. When pressed evenly from the direction,
The applied pressing force is evenly applied to the entire laminated webs, and the respective layers are evenly pressed against each other, resulting in high quality without twisting or warping.

The table below shows one of the square paper tubes 30 of this embodiment.
It is a compression resistance test result per book, the length S of one side in FIG. 14 = 45 mm, the plate thickness t = 2.4 mm, the length L = 5
This is data at an ambient temperature of 20 ° C. and a humidity of 65% in the case of 00 mm.

[0045]

[Table 1]

The square paper tube 30 has the strength as described above, and can be used for purposes such as a girder material for a pallet as shown in FIG. This pallet consists of two boards 105, 105 arranged in parallel.
A plurality of the square paper tubes 30 are arranged in parallel and interposed between the two. However, since the square paper tubes 30 are not twisted or warped, the square paper tubes 30 are closely joined to the board 105 to form a desired shape. It is possible to retain a predetermined strength that Further, as shown in FIG. 13, the fourth layers d and d ′, which are the outer layers, are aligned from the vertical direction toward the square shaft 27,
Since a slight predetermined gap is formed between the abutting portions 89d, 89d, the corner portion of the square paper tube after completion does not stick out from the quadrangular shape having one side L dimension to the outside.
The bond with 5 is kept tight. In addition, this square paper tube 30
Since it has no twist or warp and has high quality and high strength, it can be used for a structure such as a leg of a chair, a cross beam, or a backrest, which is entirely made of paper products, as shown in FIG.
Needless to say, it can be applied to various products such as tables and beds.

As described above, according to the present embodiment, not only the paper tube having a rectangular cross-section which is sequentially laminated linearly in the axial direction and pressure-bonded can be manufactured simply and continuously, but also the fourth layer as an outer layer. The inner layer is one of the first to third strips 31, 32,
Since it is configured by bending 33 and the abutting portions thereof are sequentially laminated so as to be alternately symmetrical, it is possible to manufacture an extremely uniform and strong rectangular paper tube.

Moreover, since the fourth layers d and d'which are outer layers are composed of the two fourth strips 34 of the same shape which are bent in a V-shaped cross section, they are applied by the second crimping portion 71. Since the pressing force is pressed through the outer layer composed of two sheets of the fourth belt-shaped paper 34 having the same V-shaped cross section, the pressing force is uniformly applied to all the layers already laminated. Therefore, the layers are pressed against each other uniformly, so that it is possible to obtain an extremely high-quality rectangular paper tube 30 without twisting or warping.

As a result, the square paper tube 3 is attached to a flat board or the like.
Since the side surface of No. 0 can be tightly attached without a gap and has high strength, it can be used as, for example, a building material or a girder material for a pallet. In addition, it can be used for various structures such as chairs and table legs, which are entirely paper products, by taking advantage of the high quality and high strength rectangular paper tube without twisting or warping. It is possible.

Further, since the strip-shaped papers 31 to 34 are supplied to the square shaft 27 in the axial direction thereof and stacked on the square shaft 27, the supply speed of the strips 31 to 34 and the square papers. The stacking speed on the mold shaft 27, that is, the transport speed of the manufactured square paper tube 30 is equal to the stack speed, and can be set to a very high speed, so that the productivity is high.

Further, the rollers 22 in the pressure-bonding portions 65 and 71 simultaneously press from all four directions to form the square shaft 27.
Since the square paper tube can be formed by sandwiching it with each other, a square paper tube tightly folded into a square shape can be obtained. Further, since the four corners of the square shaft 27 are formed in a predetermined R shape, the corners 97a do not protrude outside the quadrangular shape at the bent portion, and the layers are tightly stacked. Moreover, since the fourth layers d and d'which are outer layers are joined to each other from the vertical direction toward the square shaft 27, and a predetermined gap is slightly formed in the butted portions 89d and 89d,
The corner portion does not protrude outward from the quadrangular shape having L dimension on one side. Therefore, it is convenient for mounting on the flat board or the like as described above.

It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and not for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents within the technical scope of the present invention. For example, in the embodiment described above, the square shaft 27
In the above description, the square cross section is taken as an example, but the present invention is not limited to the square cross section and can be applied to various rectangular cross sections. Further, although the square paper tube 30 has a four-layer structure, for example, as shown in FIG.
It is also possible to have a five-layer structure as shown in FIG.

Further, it is preferable that the layers inside the outer layer of the rectangular paper tube are laminated so as to be alternately symmetrical as in the present embodiment, but the present invention is not limited to this and, for example, sequentially. If it is configured so as to be displaced at different positions in the two layers where the abutting portions are overlapped with each other, or if the material is compositely laminated with a material other than paper having strength such as glass fiber or carbon yarn, predetermined uniformity and strength can be obtained. Can be secured.

[0054]

As described above, according to the present invention, not only a paper tube having a rectangular cross section which is sequentially laminated linearly in the axial direction and pressure-bonded can be manufactured simply and continuously, but also inside the outer layer. The layers are made by bending a sheet of paper that has four square sides, and the abutting parts are laminated in order so that they are at different positions. Square paper tube can be manufactured.

Moreover, since the outer layers are composed of two strip-shaped papers of the same shape facing each other and bent so that two adjacent surfaces are formed, a roller is applied through this. The applied pressing force can be uniformly applied to all the layers already laminated. Therefore, since the layers are pressed against each other uniformly, it is possible to obtain an extremely high-quality rectangular paper tube without twisting or warping.

As a result, the side surface of the square paper tube can be tightly attached to a flat board without a gap, and since it has high strength, it can also be used as a structural material for construction or a girder material for pallets, for example. it can. Further, by taking advantage of such a high quality and high strength rectangular paper tube, it is possible to use it for various structures such as chairs and table legs which are entirely paper products.

Further, since the strip-shaped paper is supplied to the square shaft in the axial direction and laminated on the square shaft, the feeding speed of the strip paper and the stacking speed on the square shaft, that is, Since it is equal to the transport speed of the manufactured square paper tube and can be set at an extremely high speed, the productivity is high.

Further, since the square paper tube can be molded by being pressed by a plurality of rollers and sandwiched by the square shaft, a square paper tube tightly folded into a square shape can be obtained.
Further, since the corners of the square shaft are formed in a predetermined chamfered shape or R-shape, the corners do not protrude outside the quadrangular shape at the bent portion of the square paper tube, and the layers are closely packed with each other. Since they are laminated, the corners of the completed square paper tube do not protrude outward from the square shape. This is convenient for mounting on a flat board or the like.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of an apparatus for manufacturing a rectangular paper tube according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line P-P shown in FIG.

3A is a side view showing the first molding portion 62 shown in FIG. 1, FIG. 3B is a sectional view taken along the line Q-Q, and FIG.
[FIG. 6] is a partial plan view.

FIG. 4 is a sectional view taken along line VV shown in FIG.

5 is a cross-sectional view taken along the line WW shown in FIG.

FIG. 6 is a side view of the first crimping portion shown in FIG. 1.

7 is an enlarged cross-sectional view of the main part of the first crimping part shown in FIG.

8 is a cross-sectional view taken along line RR shown in FIG.

FIG. 9 is a cross-sectional view showing a power transmission mechanism for a roller.

FIG. 10 is a cross-sectional view showing a mounting state of rollers.

FIG. 11 is a cross-sectional view showing a position of a roller showing manufacturing of a rectangular paper tube.

FIG. 12 is a sectional view taken along line XX shown in FIG.

13 is a cross-sectional view taken along the line YY shown in FIG.

14 is a perspective view showing a square paper tube according to an embodiment of the present invention manufactured by the apparatus shown in FIG.

FIG. 15 is a perspective view showing a rectangular paper tube according to another embodiment.

FIG. 16 is a perspective view showing a usage example of a rectangular paper tube.

FIG. 17 is a perspective view showing another usage example of the rectangular paper tube.

[Explanation of Codes] 2 ... Fixed support plate, 22 ... Roller, 27 ... Square shaft, 27a ... Corner, 31 ... First strip paper (strip), 32 ... Second strip paper (strip), 33 ... Third band-shaped paper (band-shaped paper), 34 ... Fourth band-shaped paper (band-shaped paper), 62 ... First molding part, 64 ... Second molding part, 65 ... First crimping part, 67 ... Third molding part, 70 ... 4th molding part, 71 ... 2nd crimping part, 72 ... Cut part, 88a-88d ... Gap, 82a-82d ... 1st molding device-4th molding device, (molding device) 89a-89d ... Butt part, a , B, c ... First layer to third layer (layer), d, d '... Fourth layer (outer layer).

Claims (3)

[Claims] 1. Formed by bending a plurality of strips (31, 32, 33, 34) in the width direction of the strips (31, 32, 33, 34), stacking them, and pressing them while sending them in the longitudinal direction. In the square paper tube, the strip-shaped paper (31, 32, 33) folded in the width direction so that four square surfaces are formed is formed at its abutting part (89a, 89a).
b, 89c) are laminated so that each layer (a, b, c) is at a different position, and two strips of paper (34) are folded in the width direction so that two adjacent surfaces are formed. ) Is pressure-bonded so as to face each other in two directions to form an outer layer (d, d ′). 2. A plurality of strip-shaped papers (31, 32, 33, 34) are sequentially bent in the width direction along a rectangular shaft (27) serving as a core bar to be laminated, and the rectangular shaft (27) In a method for manufacturing a rectangular paper tube formed by crimping while sending in the axial direction, a strip-shaped paper sequentially supplied in the axial direction of the rectangular shaft (27).
A molding machine provided with (31, 32, 33) surrounding the square shaft (27) so as to form a predetermined gap (88a, 88b, 88c).
(82a, 82b, 82c) are sequentially bent in the width direction so as to form four rectangular surfaces, and the plurality of strips (31, 32, 33) formed in this way are abutted with each other ( 89a, 89b, 89c)
Are laminated so that each layer (a, b, c) is at a different position, and two strips of paper (34) supplied from two directions are directed toward the opposite edges of the square shaft (27). , Formed by bending in the width direction so that two adjacent surfaces are formed by a molding machine (82d) provided around the square shaft (27) so as to form a predetermined gap (88d). After that, the four rollers (22) provided on one surface of the fixed support plate (2) penetrating the square shaft (27) in the center to face the side surface of the square shaft (27) and the square roller (22). Between the mold shaft (27) and the strip (31,
32, 33, 34) is sandwiched and pressed and fed in the axial direction to form an outer layer (d, d ′), which is a method for manufacturing a square paper tube. 3. The square shaft (27) has four corners.
The method for manufacturing a square paper tube according to claim 2, wherein (27a) is formed into a predetermined chamfered shape or an R shape.