JP2004001579A - Tubular object molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tubular object molding apparatus which molds a tubular object by winding a sheet-like blank around a mandrel so that both ends of the blank are superposed over each other, and binding these mutually superposed ends. <P>SOLUTION: This apparatus is constituted of a mandrel 22 around which the sheet-like blank 3 is wound so that its both ends are superposed over each other, installed on stations for molding the tubular object and a support mechanism for supporting the sheet-like blank 3 in the state that both ends of the blank 3 are superposed over each other and at the same time, transferring the blank 3 from one station for molding the tubular object to the other. The support mechanism is equipped with a support part 7la for supporting the mutually superposed both ends from inside and a jamming part 66 for jamming the ends toward the support 7la from outside. In addition, the support mechanism has a notched part 22a for inserting the support 7la on the outer peripheral face of the mandrel 22. It is possible to almost prevent irregularities from being generated on the outer peripheral face of the mandrel 22 particularly without reducing the thickness of the support 7la of the support mechanism, so that the tubular object almost corresponding to the shape of the outer peripheral face of the mandrel 22 is molded. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a tubular body forming apparatus in which a sheet blank is wound around a mandrel so that both ends thereof overlap each other, and a tubular body is formed by joining the mutually overlapped both ends, particularly paper. It is most suitable for use in forming a tubular body portion such as a tubular paper portion in a container such as a cup.

Conventionally, a paper cup composed of a substantially frustoconical cylinder paper and a substantially circular bottom paper fitted and fixed near an end opening on the small diameter side of the cylinder paper has been continuously formed. A paper cup forming machine as shown in FIGS. 8 to 10 is known.

As shown in FIG. 8, this conventional paper cup forming machine has a turret 2 on which eight metal mandrels 1 each having a substantially frustoconical outer peripheral surface are attached at substantially equal intervals along the outer periphery thereof. It has. Note that these mandrels 1 are arranged on the turret 2 such that the axial direction thereof substantially coincides with the radiation direction of the turret 2 and their large-diameter ends face the center of the turret 2. The turret 2 rotates intermittently by about 45 ° counterclockwise in FIG. 8 about the vertical axis, and the eight mandrels 1 are arranged along the outer periphery of the turret 2. The turret 2 is sequentially stopped at stations A to H at two places with the intermittent rotation of the turret 2. Then, in these eight stations A to H, as described below, various processings or inspection steps necessary for forming the paper cup are repeatedly performed for each intermittent rotation of the turret 2.

(1) Station A
In this station A, a bottom paper supply arm 11 for supplying the bottom paper 10 to the mandrel 1 is disposed so as to be able to move forward and backward with respect to the mandrel 1. The base paper 10 is composed of a substantially circular flat plate portion 10a and an annular narrow width margin portion 10b formed by integrally rising from the outer periphery of the flat plate portion 10a. Then, the bottom paper supply arm 11 advances toward the mandrel 1 while holding the bottom paper 10 with the margin portion 10b directed away from the central axis of the turret 2, and forms a concave portion on the outer surface of the mandrel 1. The bottom paper 10 is fitted into the bottom paper holding portion 1a formed as described above, as shown in FIG. 9, so that the bottom paper 10 is air-chucked to the mandrel 1. Next, the bottom paper supply arm 11 moves backward and returns to the original position shown in FIG.

(2) Station B
In this station B, a bottom sheet detecting means 12 for detecting whether or not the bottom sheet 10 is accurately held by the bottom sheet holding section 1a of the mandrel 1 is arranged. The bottom paper detecting means 12 may be an optical sensor having a light emitting element and a light receiving element, and the intermittent rotation of the turret 2 continues only when the bottom paper 10 is detected by this optical sensor. Is

(3) Station C
In this station C, a conveyor mechanism 4 and a blank positioning table 5 for supplying a sheet blank 3 for forming a substantially frustoconical cylinder paper to the mandrel 1 are arranged. The blank 3 is composed of a somewhat curved rectangular sheet member so as to form a substantially frustoconical cylinder paper by joining a pair of marginal portions consisting of both end portions thereof. The surface is covered with a thermoplastic resin.

The conveyor mechanism 4 includes a pair of upper and lower belt conveyors, and transports the blank 3 sandwiched between the pair of belt conveyors toward the center of the turret 2 and sequentially supplies the blank 3 to the blank positioning table 5. During the supply, the blank 3 is heated at both left and right ends by a heating means 6 such as a pair of left and right gas burners disposed on the left and right sides of the conveyor mechanism 4 to melt the thermoplastic resin on the surface. You. When the blank 3 supplied to the blank positioning table 5 is positioned at a predetermined position on the blank positioning table 5 by the fixed pin 5a and the movable pin 5b, the blank positioning table 5 moves in the direction toward the center of the turret 2. The mandrel advances to move below the mandrel 1, and holds the blank 3 at a predetermined position below the mandrel 1.

Next, the blank 3 is pressed against the lower end of the mandrel 1 at a position between the left and right ends thereof by a pressing lever such as a blank pressing lever shown in FIG. Next, a pair of left and right winding arms 7 arranged obliquely below the blank 3 and curved in a substantially arc shape are rotated obliquely upward from the left and right sides toward the axis of the mandrel 1. Accordingly, the blank 3 is wound around the outer peripheral surface of the mandrel 1 in a substantially frustoconical shape, and a pair of margins formed on both right and left ends thereof are overlapped with each other, thereby forming a substantially frustoconical tubular paper.

In this case, since a substantially rectangular notch 20 is formed at the front of the blank positioning table 5, the winding arm 7 can rotate obliquely upward through the notch 20. For this reason, the blank positioning table 5 at the forward position does not hinder the rotation of the winding arm 7 obliquely upward. Further, since the bottom paper 10 is fitted to the bottom paper holding portion 1a of the mandrel 1 and air-chucked to the mandrel 1, as shown in FIG. 9, the bottom paper 10 hinders the winding operation of the blank 3. There is no. As shown in FIG. 9, the blank 3 is wound around the outer peripheral surface of the mandrel 1 such that the small-diameter end of the cylindrical paper 3 slightly protrudes from the front end surface of the mandrel 1. This is because, at a station F to be described later, the end on the small diameter side of the paper cylinder 3 is bent so as not to hinder the bottom bending operation of attaching the bottom paper 10 to the paper cylinder 3.

Next, the blank positioning table 5 moves backward and returns to the original position shown in FIG. 8, and a pair of rubber pads 8 attached to the distal end of the holding lever 9 are superimposed on each other as shown in FIG. The glued portions are pressed to weld each other. In this case, as described above, the small-diameter end of the cylindrical paper 3 slightly protrudes from the distal end surface of the mandrel 1, and thus the small-diameter end of the pair of margins is formed by the pad 8 of the holding lever 9. It is not pressed.

Therefore, in the station C, the blank 3 is formed into a substantially frustoconical cylindrical shape, and a pair of margins at both ends thereof are fixed to each other.

(4) Stations D and E
At these stations D and E, a first bottom heating arm 17 and a second bottom heating arm 18 are respectively arranged so as to be able to move back and forth with respect to the mandrel 1.

In these stations D and E, the first and second bottom heating arms 17 and 18 respectively advance to insert their leading end surfaces into the bottom paper 10 held by the bottom paper holding section 1a of the mandrel 1. Therefore, the bottom paper 10 and the small-diameter end of the cylindrical paper 3 located around the bottom paper 10 are heated. After the above-mentioned heating, these bottom heating arms 17 and 18 move backward and return to the original positions shown in FIG. 8, respectively.

(5) Station F
In this station F, a bottom folding arm 14 is arranged as shown in detail in FIGS.

In FIG. 9, the bottom paper 10 is fitted to the bottom paper holding portion 1a of the mandrel 1 and is air chucked to the bottom pushing arm 1b. The blank 3 is wound around the outer peripheral surface of the mandrel 1 and a pair of glued portions is overlapped with each other at the upper portion of the mandrel 1 to form a substantially conical tubular paper. The end on the small diameter side of the tubular paper 3 slightly protrudes from the distal end surface of the mandrel 1. The pad 8 of the holding lever 9 presses the pair of marginal portions of the cylinder paper 3 except for the small-diameter end. Further, the bottom folding arm 14 is arranged so as to be able to move forward and backward with respect to the tip end surface of the mandrel 1 (and, consequently, the bottom paper 10).

In this station F, the bottom paper pushing arm 1b and the bottom bending arm 14 of the mandrel 1 advance from the return position shown in FIG. 9 to the forward movement position shown in FIG. The part (ie, the bottom) is folded inward.

That is, when the bottom pushing arm 1b advances outward along the axial direction of the mandrel 1, the bottom sheet 10 held by the bottom sheet holding section 1a of the mandrel 1 is pushed out from the bottom sheet holding section 1b. The margin portion 10b is brought into contact with the inner surface of the cylinder paper 10. When the bottom folding arm 14 advances as described above and is pressed against the bottom paper pushing arm 1b via the flat plate portion 10a of the bottom paper 10, the bottom of the paper tube 3 is formed on the front surface of the bottom folding arm 14. It is guided in the molding recess 19 and bent inward. For this purpose, the margin 10b of the bottom paper 10 is sandwiched between the bottom of the paper cylinder 3 and the portion of the paper cylinder 3 adjacent to the bottom. Further, by the sandwiching, the margin portion 10b is welded to the bottom portion and the adjacent portion, respectively. Then, the bottom folding arm 14 moves backward and returns to the original position shown in FIG. 9, but the bottom sheet pushing arm 1b of the mandrel 1 is kept at the forward movement position shown in FIG.

Therefore, in this station F, bottom molding is performed in which the bottom paper 10 is attached to the cylinder paper 3 and fixed.

(6) Station G
In this station G, the bottom crimping arm 15 is arranged so as to be able to move forward and backward with respect to the mandrel 1.

In this station G, the bottom pressure bonding arm 15 moves forward to press the center portion of the bottom pressure bonding arm 1b through the flat plate portion 10a of the bottom paper 10 to the bottom paper pushing arm 1b. Crimp to Then, in this state, the laminated portion of the bottom portion of the sleeve paper 3 and the margin portion of the bottom paper 10 is sandwiched from both inside and outside by the pair of knurls formed at the central portion and the peripheral portion, and is pressed. The margin of the bottom paper 10 is firmly welded to the bottom of the cylinder paper 3, and as a result, an unfinished paper cup formed of the cylinder paper 3 and the bottom paper 10 is formed. Then, the bottom pressing arm 15 moves backward and returns to the original position shown in FIG. 8, but the bottom sheet pushing arm 1b of the mandrel 1 is kept at the forward movement position shown in FIG.

(7) Station H
In this station H, a paper cup take-out arm 16 is arranged so as to be able to move forward and backward with respect to the mandrel 1.

In this station H, first, the bottom paper pushing arm 1b of the mandrel 1 in the forward movement position shown in FIG. 10 is further advanced to push the paper cup formed of the cylinder paper 3 and the bottom paper 10 outward from the mandrel 1. . Then, the paper cup take-out arm 16 moves forward and comes into contact with the bottom paper 10, and moves backward when the unfinished product of the paper cup is air-chucked. The paper cup is pulled out from the mandrel 1 and transferred to a predetermined position. Further, the bottom sheet pushing arm 1b moves backward and returns to the original position shown in FIG.

Unfinished paper cups obtained through various processing or inspection processes in stations A to H described above are curled with the curl machine (not shown) so that the large-diameter end of the paper tube 3 is curled outward. , Finished into a finished paper cup.

In the conventional paper cup forming machine shown in FIGS. 8 to 10, at the station F, the end on the small diameter side of the paper cylinder 3 is bent so as not to hinder the bottom bending operation of attaching the bottom part 10 to the paper cylinder 3. As described above, the end on the small diameter side of the cylindrical paper 3 is slightly protruded from the front end surface of the mandrel 1. Therefore, the small-diameter end portions of the pair of margin portions of the sleeve paper 3 are not pressed by the pad 8 of the holding lever 9, so that the mandrel 1 is not pinched by the pad 8 of the holding lever 9. In addition, there is a possibility that the pair of marginal portions at the small-diameter side ends are not welded to each other firmly.

In order to correct such a drawback, the present inventor uses a different apparatus from the bottom forming in which the body forming performed in station C in the conventional paper cup forming machine shown in FIGS. In order to be able to do so, the present inventors have conceived to carry out this by using a body forming apparatus as an auxiliary device provided separately from the conventional paper cup forming machine. In this case, a plurality of mandrels are attached to the turret at substantially regular intervals along the outer periphery of the turret, and the turret is intermittently rotated, as in the case of the conventional paper cup molding machine. By doing so, it is conceivable that the plurality of mandrels are sequentially fed to a station for waist forming.

However, when configured as described above, both the bulk and the weight of the intermittently rotating portion including the plurality of mandrels are increased, and the drive mechanism of the intermittently rotating portion can be configured to be small. Since it is not possible, the configuration of the entire body stretching forming apparatus becomes complicated and large.

The present invention has been made in order to solve such a problem, and a sheet-shaped blank is wound around a mandrel so that both ends thereof overlap with each other, and the overlapping both ends are joined to form a tube. A cylindrical body forming apparatus configured to form a body, wherein a plurality of support mechanisms for supporting the sheet blank in a state where both ends thereof overlap each other are intermittently moved, and the plurality of support mechanisms are intermittently moved. The support mechanism is configured to be sequentially fed to a station for forming a tubular body, and a mandrel around which the sheet blank is wound and a mandrel around which the sheet blank is wound around the mandrel. Blank wrapping means for each, the intermittent movement of the support mechanism causes the support mechanism to In a tubular body forming apparatus configured to support the sheet-shaped blank in a state where both end portions thereof are overlapped with each other and to transfer the tubular blank from a station for forming the tubular body to the next station, the supporting mechanism includes A supporting portion for supporting both ends overlapping each other from the inside thereof, and a pressing portion for pressing against the supporting portion from the outside thereof, for inserting the supporting portion into the outer peripheral surface of the mandrel. The present invention relates to a cylindrical body forming apparatus characterized in that a notch portion is provided.

According to the present invention, both overlapping ends can be elastically clamped by the supporting portion and the pressing portion. Further, in the present invention, a heating means for heating at least one of the pressing portion and the support portion can be provided.

According to the present invention, a plurality of support mechanisms for supporting a sheet-shaped blank wound in a cylindrical shape with both ends overlapping each other are intermittently moved, and the plurality of support mechanisms are cylindrical members. A mandrel, which is configured to be sequentially fed to a molding station and on which a sheet-like blank is wound, is provided at the cylinder molding station. Therefore, the plurality of mandrels are intermittently moved, and the plurality of mandrels are intermittently moved as compared with the conventional example of FIG. 8 in which the plurality of mandrels are sequentially fed to a station for forming a cylindrical body. The bulk and the weight of the portion to be made can be significantly reduced, and the drive mechanism for the intermittently moving portion can be made small. Therefore, the configuration of the entire cylindrical body forming apparatus can be made simple and small. it can.

Further, according to the present invention, it is possible to make the outer peripheral surface of the mandrel hardly have irregularities without particularly reducing the thickness of the support portion of the support mechanism. A corresponding cylindrical body can be formed.

According to the second aspect of the present invention, the mutually overlapping ends of the sheet blank can be elastically clamped from both inside and outside, so that the support of the sheet blank by the support mechanism can be reliably performed. it can.

Further, according to the third aspect of the present invention, the two ends of the sheet blank can be heated and welded only by sandwiching the overlapping both ends between the support portion and the pressing portion. Heat welding can be performed simply and efficiently.

Next, an embodiment in which the present invention is applied to a body tension forming apparatus of a paper cup forming machine will be described with reference to FIGS. In this embodiment, the same parts as those of the conventional example shown in FIGS. 8 to 10 are denoted by the same reference numerals, and the description thereof will be omitted as necessary.

FIG. 1 schematically shows the entire body forming apparatus. The body forming apparatus is a conventional paper cup forming machine shown in FIGS. It is for carrying out molding, and constitutes an auxiliary device of a paper cup forming machine as a main device having almost the same configuration as the conventional paper cup forming machine.

That is, the paper cup forming machine as the main device in the present embodiment includes a station A for supplying the bottom sheet, a station B for detecting the bottom sheet, and a heating section for the bottom in the conventional paper cup forming machine shown in FIG. Or stations D and E, a station F for bottom folding, a station G for bottom crimping, and a station H for paper cup removal. The paper cup forming machine as the main device is different from the conventional paper cup forming machine shown in FIG. 8 in that the station C for body forming shown in FIGS. There is provided a paper cylinder supply station for supplying the paper cylinder 3 obtained from the molding apparatus.

As shown in FIG. 1, the body tension forming apparatus according to the present embodiment includes a support mechanism 50 having a pressing arm 61 and a support arm 71 constituting a heat seal bar. The turret 51 is provided with eight turrets. The turret 51 rotates intermittently about 45 ° clockwise in FIG. 1 around the horizontal axis, and the eight sets of support mechanisms 50 are arranged along the outer periphery of the turret 51. The turret 51 is configured to stop sequentially at the stations A to H with the intermittent rotation of the turret 51. Then, in the station A, the supply of the sheet-shaped blank 3 and the forming of the body blank are performed, and in the stations BF, the heat welding of the pair of marginal portions consisting of the left and right end portions of the cylinder paper 3 is continuously performed. In the station G, the cylinder paper 3 is taken out, and in the station H, the support arm 71 is moved back.

As shown in FIG. 2, the support mechanism 50 includes a guide block 54 attached to the inner surface of the turret 51. The guide block 54 is provided with thrust bearings 52 and 53, respectively. The pressing arm 61 is supported by the thrust bearing 52 so as to be able to reciprocate in the axial direction substantially coincident with the radial direction of the turret 2, and a heater is embedded at the tip of the thrust bearing 52, and the heat sealing piece is provided. The constituting pressing member 66 is provided. Further, the support arm 71 is supported by the thrust bearing 53 so as to be able to reciprocate in the axial direction substantially parallel to the axial direction of the pressing arm 61, and the distal end thereof is bent to form the support portion 71a. To form an L-shape as a whole.

The pressing arm 61 is constantly urged upward in FIG. 2 by a return spring 65 interposed between the pressing arm 61 and the guide block 54, and the pressing arm 61 and the operating arm 67 are connected to each other. The operation arm 67 is pressed downward in FIG. 2 via a pressure adjusting spring 64 interposed therebetween. A rotating wheel 63 as a cam follower is attached to one end of the operating arm 67, and the rotating wheel 63 is pressed against the cam surface of the first operating cam 62 by the urging force of a pressure adjusting spring 64. The support arm 71 is constantly urged downward in FIG. 2 by a return spring 74 interposed between the support arm 71 and a chassis 75 fixed to the turret 51. A rotating ring 73 as a cam follower is attached to an intermediate portion of the support arm 71, and the rotating ring 73 is pressed against the cam surface of the second operation cam 72 by the urging force of the return spring 74.

In the station A, various mechanisms necessary for supplying the sheet-like blank 3 and forming the body are arranged.

That is, in this station A, a conveyor mechanism 4 composed of a pair of upper and lower belt conveyors 4a and 4b and a blank positioning table 5 are arranged, similarly to the station C of the conventional paper cup molding machine shown in FIG. Have been. The blank 3 is sandwiched between the pair of belt conveyors 4a and 4b, transported in a direction substantially parallel to the axial direction of the mandrel 22 disposed in the station A, and sequentially transferred to the blank positioning table 5. Supplied. When the blank 3 supplied to the blank positioning table 5 is positioned at a predetermined position on the blank positioning table 5 by the fixed pin 5a and the movable pin 5b in the same manner as in the case of FIG. The mandrel 22 moves forward in a direction substantially parallel to the axial direction and moves to a position below the mandrel 22, and holds the blank 3 at a predetermined position below the mandrel 22. In the present embodiment, it is not necessary to provide a pair of right and left heaters disposed on both left and right sides of the conveyor mechanism 4 in the case of the conventional example shown in FIG. The reason is that the pair of glued portions of the cylinder paper 3 can be successively heated and welded by the pressing arm 61 that is configured.

The mandrel 22 is attached to the chassis 21 as described below with reference to FIGS. 1 and 3 to 6.

That is, as shown in FIGS. 3 to 6, the guide block 23 is fixed to the chassis 21, and a pair of through holes 44 are formed in the guide block 23. Two pairs of thrust bearings 45 are provided in the pair of through holes 44, respectively. The pair of thrust bearings 45 support the pair of guide shafts 24 so that they can reciprocate in the axial direction. I have.

Since the mandrel 22 is attached to one end of each of the pair of guide shafts 24 as shown in FIG. 6, the mandrel 22 cannot rotate around its axis. 6 so that it can reciprocate in the left-right direction of FIG. When the turret 51 rotates intermittently, the axial direction of the mandrel 22 substantially coincides with the movement direction of the pressing piece 66 of the pressing arm 61 and the supporting piece 71a of the supporting arm 71 in the station A, and The end on the small diameter side of the mandrel 22 faces the movement direction. The other ends of the pair of guide shafts 24 are respectively attached to rear mounting blocks 25 for connecting the guide shafts 24 to each other. Further, a front mounting block 32 is slidably mounted on the pair of guide shafts 24, and a blank stopper 31 is fixed to the front mounting block 32.

A pair of adjustment bolts 33 is mounted on the surface of the front mounting block 32 on the side opposite to the mandrel 22 side, and the pair of adjustment bolts 33 is fixed by a nut 33a after adjusting the amount of protrusion. . Further, a pair of stopper operation levers 34 are disposed to face the pair of adjustment bolts 33, respectively, and the pair of stopper operation levers 34 are integrally connected to a common support shaft 46. A pair of spring mounting shafts 35 is mounted on a surface of the front mounting block 32 on the side opposite to the mandrel 22 side, and a guide block is provided between the pair of spring mounting shafts 35 and the guide block 23. The return springs 36 housed in the 23 are interposed respectively. Therefore, the pair of stopper operation levers 34 is held in a state where the tips thereof are in contact with the tips of the adjustment bolts 33.

3 to 5, the blank holding lever 37 is integrally connected to the support shaft 46, so that the blank holding lever 37 is rotatable about the support shaft 46 as a fulcrum. I have. A pad 38 made of rubber is attached to the tip of the blank holding lever 37.

The distal end of the mandrel operating lever 27 is opposed to the rear mounting block 25, and the base end of the mandrel operating lever 27 is integrally connected to the support shaft 48. A pair of return springs 26 each having one end inserted into the guide block 23 is interposed between the guide block 23 and the rear mounting block 25, and the rear mounting block 25 is separated by the pair of return springs 26. It is always energized toward the right in FIG. Therefore, the rear mounting block 25 is crimped to the tip of the mandrel operating lever 27.

An air pipe 47 is connected to the rear mounting block 25. The air pipe 47 is connected to the air chamber 22b of the mandrel 22 via the air hole 25a of the rear mounting block 25 and the center hole 24a of the pair of guide shafts 24, respectively. Communicating. The mandrel 22 has a plurality of air holes 22c extending from the air chamber 22b to the outer peripheral surface of the mandrel 22.

A notch 22a is formed at the upper end of the mandrel 22 so that the support 71a of the support arm 71 can be just inserted. Further, below the mandrel 22, a pair of left and right winding arms 7, which may have the same configuration as that of the conventional example shown in FIG. The pair of winding arms 7 are rotatably supported by a support shaft 49 attached to the chassis 21. The pair of winding arms 7 are pushed up by push-up rods (not shown) connected to the winding arms 7, respectively, so that the support shafts extend obliquely upward from both left and right sides toward the axis of the mandrel 22. Rotation is performed with the support 49 as a fulcrum, and their pressing surfaces are pressed against the outer peripheral surface of the mandrel 22 via the blank 3. Therefore, the pressing surfaces of the pair of winding arms 7 are formed in a substantially semicircular shape having substantially the same diameter as the outer periphery of the central portion of the mandrel 22.

Next, the operation of the waist-forming apparatus configured as described above will be described. In eight stations of the waist-forming apparatus, various processing steps necessary for shaping the paper tube are described below. And the like are repeated for each intermittent rotation of the turret 51.

(1) Station A
At the time when the body stretching process is started at the station A, the various mechanisms and the support mechanisms 50 arranged at the station A are held in the state described below.

That is, the blank positioning table 5 is held at the return position shown by the solid line in FIG. 8, and the mandrel 22, the blank holding lever 37, the blank stopper 31 and the winding arm 7 are also held at the return position shown in FIG. I have. Further, since the support arm 71 of the support mechanism 50 is held at the return position shown in FIG. 2, the support part 71 a formed of the tip end is held in a state inserted into the notch 22 a of the mandrel 22. Further, since the pressing arm 61 is held at the return position shown in FIG. 2, a solid line shown in FIG. 2 is provided between the pressing piece 66 of the pressing arm 61 and the supporting portion 71a of the supporting arm 71. Thus, a sufficiently large gap is formed.

In the station A, from the initial state, first, as described above, the blank 3 sequentially supplied by the conveyor mechanism 4 and the blank positioning table 5 is held at a predetermined position below the mandrel 22. At this time, since the blank stopper 31 is at the return position shown in FIG. 3, the blank 3 is positioned by bringing the blank stopper 31 at the return position into contact with its front end.

Next, since the support shaft 46 makes a forward rotation in the clockwise direction in FIG. 3, the stopper operating lever 34 similarly makes a forward rotation about the support shaft 46 as a fulcrum. The mounting shaft 35, the mounting block 32, and the blank stopper 31 integrally move forward to the position shown in FIG. At the same time, the blank holding lever 37 rotates forward in the clockwise direction in FIG. 3 around the support shaft 46 in conjunction with the forward rotation of the support shaft 46. 38 presses the blank 3 against the lower end of the mandrel 22 at an intermediate position between the left and right ends thereof, as shown in FIG.

Then, a pump (not shown) sucks air from the air pipe 47, so that the air hole 22c of the mandrel 22, the air chamber 22b of the mandrel 22, the center hole 24a of the guide shaft 24, and the air hole 25a of the rear mounting block 25 are formed. , Air starts to be sucked through each of them. Then, the pair of winding arms 7 move forward and backward from the chain line position to the solid line position in FIG. 7 with the support shaft 49 as a fulcrum. Therefore, the blank 3 is wound around the outer peripheral surface of the mandrel 22 in a substantially frustoconical shape, and a pair of girth portions including both left and right ends thereof are overlapped with each other as clearly shown in FIGS. 4 and 7. It becomes a truncated cone paper.

In this case, one of the pair of winding arms 7 (the right winding arm 7 in the case of FIG. 4) rotates forward before the other, so that a pair of the left and right ends of the blank 3 is provided. The vertical relationship of the parts to each other is always uniquely determined. Further, since air is sucked from the air holes 22c of the mandrel 22, the winding arm 7 does not loosen the winding of the blank 3 around the outer peripheral surface of the mandrel 22. Further, since the blank stopper 31 moves forward to the position shown in FIG. 4 and retracts with respect to the blank 3 as described above, the front end of the blank 3 rubs against the blank stopper 31 when the blank 3 is wound, and is damaged. I can't. Further, as in the case of the conventional paper cup forming machine shown in FIGS. 8 to 10, the end of the cylindrical paper 3 is wound around the outer peripheral surface of the mandrel 22 so as to slightly protrude from the front end surface of the mandrel 22. It is not necessary, and as shown in FIG.

Next, the blank positioning table 5 moves backward and returns to the original position as shown in FIG. Further, as shown by a chain line in FIG. 2, when the first operation cam 62 moves forward, the pressing piece 66 of the pressing arm 61 moves forward toward the support portion 71 a of the support arm 71, and this support Since the pair of margins of the cylinder paper 3 are elastically pressed against the portion 71a by the urging force of the pressure adjusting spring 64, the pair of margins are heated and welded to each other. In this case, the supporting portion 71a extends over the entire length of the inner surface of the pair of margins, and the pressing piece 66 extends over the entire length of the outer surface of the pair of margins. Is elastically sandwiched between the supporting portion 71a and the pressing piece 66 and is welded by heating.

Then, since the support shaft 46 rotates counterclockwise in FIG. 4, the blank stopper 31 returns to the original position together with the spring mounting shaft 35 and the front mounting block 32 as shown in FIG. The lever 37 and the pad 38 also return to their original positions as shown in FIG. 5, and release the pressing of the blank 3 against the lower end of the mandrel 22. At the same time, the pair of winding arms 7 return from the solid line position in FIG. 7 to the chain line position, respectively.

Next, air is supplied from the air pipe 47 to the air hole 25a of the rear mounting block 25. The air passes through the center hole 24a of the guide shaft 24 and the air chamber 22b and the air hole 22c of the mandrel 22, and the outer peripheral surface of the mandrel 22. Is diffused between the outer peripheral surface of the mandrel 22 and the inner surface of the cylinder paper 3 to prevent the inner surface of the cylinder paper 3 from firmly adhering to the outer peripheral surface of the mandrel 22. In addition, since the support shaft 48 rotates clockwise in FIG. 4 together with the mandrel operating lever 27, the rear mounting block 25, the pair of guide shafts 24, and the mandrel 22 are moved by the urging force of the return spring 26. 4 moves from the return position of FIG. 4 to the position of FIG. In this case, the mandrel 22 moves in the axial direction toward the end portion on the larger diameter side. The pair of margins of the sleeve paper 3 are elastically held between the support portion 71a of the support arm 71 and the pressing piece 61a of the pressing arm 61, and the lower portion thereof is formed as shown in FIG. Since the mandrel 22 is prevented from moving to the right in FIG. 5 by the blank stopper 31, it is relatively removed from the mandrel 22 as the mandrel 22 moves to the right in FIG. It will be left behind.

Then, as described above, the turret 22 rotates clockwise in FIG. 1 by about 45 °, so that the support mechanism 50 which has been in the station A until the next time the station B is supported while the cylinder paper 3 is supported. Move towards. At the same time, the supply of air to the air pipe 47 is interrupted, and the support shaft 48 rotates counterclockwise in FIG. 5, so that the mandrel 22 is moved together with the rear mounting block 25 and the pair of guide shafts 22. It returns to the original position shown in FIG.

(2) Station BF
In these stations B to F, the cylinder paper 3 is elastically clamped by the support portion 71a of the support arm 71 and the pressing piece 66 of the pressing arm 61, and is continuously heated and welded. The heat welding is also performed while the support mechanism 50 is moving between the stations A to G while supporting the sleeve 3.

Therefore, in this embodiment, since the blank or the paper 3 can be heated for a long time by the pressing arm 61 constituting the heat silver bar, it is not necessary to particularly heat the blank or the paper 3 by another heating means. Absent.

(3) Station G
In this station G, a cylinder paper receiving plate 81 for taking out the cylinder paper 3 is arranged.

The tubular paper receiving plate 81 may be formed of a rotating disk rotatable about a vertical axis, and the rotating disk may have a plurality of circular openings formed along its outer periphery. Note that the diameter of the plurality of circular openings is substantially equal to the diameter of an intermediate portion between the upper end and the lower end of the cylinder paper 3. Further, when the support portion 71a of the support arm 71 passes through the circular openings, the base end portion of the support arm 71 moves from one surface of the tube receiving plate 81 to the other surface. It has a cut portion communicating with the outer periphery of the rotating disk so that the rotary disk can be moved to a position other than the circle.

Therefore, in the station G, when the support mechanism 50 supporting the cylinder paper 3 moves to the station G, the cylinder paper 3 is moved to one of the circular openings of the cylinder paper receiving plate 81. And is held by the tubular paper receiving plate 81 from the lower end of the small diameter side. Then, when the turret 22 performs the next intermittent rotation, the first operation cam 62 moves backward, the pressing arm 61 returns from the chain line position in FIG. 2 to the solid line position, and the second operation cam 2 and the support arm 71 moves downward in FIG. 2, so that the pressing arm 61 and the support arm 71 move to the next station H while the cylinder paper 3 is held by the cylinder paper receiving plate 81. You can move.

(4) Station H
In this station H, since the second operation cam 72 moves backward, the support arm 71 that has moved forward in the station G before that returns to the original position shown in FIG.

As described in detail above, the cylinder paper 3 obtained by performing the body-stretching forming and the complete welding of the pair of margins at the stations A to F is received by the cylinder paper receiving plate 81 at the station G. After being held by the leverage paper receiving plate 81, a paper cylinder supply station of a paper cup forming machine as a main device (corresponding to a station C for body tension forming in a conventional paper cup forming machine shown in FIG. 8). Supplied to Then, the tubular paper 3 is fitted to the mandrel at this station in the same manner as shown in FIG. Further, as in the case of the stations D to H of the conventional paper cup forming machine shown in FIG. 8, the paper cup is taken out from the paper cup forming machine as an unfinished product.

In the above-described embodiment, a substantially frustoconical cylindrical portion is formed from the sheet-shaped blank 3. However, various shapes such as a substantially cylindrical shape, a substantially square cylindrical shape, and a substantially pyramid truncated pyramid shape are used. A tubular body can also be formed. Further, although the tubular portion of the paper cup is formed, a tubular portion of the box box or the like may be formed.

In the above-described embodiment, the turret 51 is provided with a plurality of support mechanisms 50 at substantially equal intervals along the outer periphery thereof, and the turret 51 is intermittently rotated. Alternatively, a plurality of support mechanisms 50 may be attached to the endless chain having a movement locus such as a rectangle at substantially equal intervals, and the endless chain may be intermittently moved.

Further, in the above-described embodiment, the overlapping both ends of the sheet-shaped blank 3 wound in a cylindrical shape are elastically applied from both the inside and the outside by the supporting portion 71a of the supporting arm 71 and the pressing portion 66 of the pressing arm 61. However, the both ends may be elastically supported by a suction arm capable of sucking the vicinity of both ends from outside. Further, since the pressing of the pressing ends 66 by the pressing pieces 66 of the pressing arm 61 is performed elastically by the pressure adjusting spring 64, there is no need to provide an elastic member such as rubber on the pressing pieces 66. For this reason, it is not necessary to frequently replace parts due to wear of the elastic member, but it is not always necessary to do so. Further, although the heater is built in the pressing piece 66 of the pressing arm 61, a heater may be built in the support portion 71a of the support arm 71, or a heater may be built in both.

In the above embodiment, the pressing arm 61 is moved forward by the first operation cam 62, and the support arm 71 is moved forward by the second operation cam 72. Although the forward movement of the support arm 71 can be reliably and easily performed, the forward movement may be performed by another operation mechanism (for example, a link mechanism or a cylinder mechanism) other than the cam.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows roughly the whole body stretching forming apparatus in one Example which applied this invention to the body stretching forming apparatus of the paper cup molding machine. FIG. 2 is a longitudinal sectional view showing the support mechanism shown in FIG. 1. FIG. 2 is an enlarged front view of a portion of a station A in FIG. 1 in a state immediately before a forward movement of a winding arm. FIG. 4 is a view similar to FIG. 3 but in a state immediately after retraction of a blank stopper after a forward movement of a winding arm. FIG. 4 is a view similar to FIG. 3 immediately after the mandrel has retreated. FIG. 5 is a sectional view taken along the line II of FIG. 4. FIG. 5 is a cross-sectional view along the line II-II in FIG. 4. It is a schematic plan view of a conventionally known paper cup forming machine. FIG. 10 is a cross-sectional view taken along the line III-III of FIG. 8 in a state before the forward movement of the bottom bending arm. FIG. 10 is a cross-sectional view along a line III-III in FIG. 8 in a state where the bottom bending arm is moving forward.

Explanation of reference numerals

3 blank (paper cylinder)
7 Winding arm 22 Mandrel 22a Notch 31 Blank stopper 50 Support mechanism 51 Turret 61 Pressing arm 66 Pressing piece (pressing portion)
71 Support arm 71a Support section A Station B Station

Claims (3)

A tubular body forming apparatus that winds a sheet-shaped blank around a mandrel so that both ends thereof overlap each other, and forms a tubular body by joining the mutually overlapping both ends,
A plurality of support mechanisms for supporting the sheet-shaped blank in a state where both ends thereof are overlapped with each other are intermittently moved so that the plurality of support mechanisms are sequentially fed to a station for forming a cylindrical body. Make up,
A station for forming the cylindrical body, a mandrel around which the sheet blank is wound, and blank winding means for winding the sheet blank around the mandrel, respectively.
By the intermittent movement of the support mechanism, the support mechanism supports the sheet blank in a state where both ends thereof overlap each other, and transfers the sheet blank from a station for forming the tubular body to a next station. In the cylindrical body molding device
The support mechanism includes a support portion for supporting the mutually overlapping end portions from the inside thereof, and a pressing portion for pressing the support portion from the outside toward the support portion,
A cylindrical body forming apparatus, wherein a cutout portion for inserting the support portion is provided on an outer peripheral surface of the mandrel. (4) The apparatus according to claim 1, wherein said overlapping end portions can be elastically clamped by said support portion and said pressing portion. 3. The apparatus according to claim 1, further comprising heating means for heating at least one of the pressing portion and the support portion.

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