Screw forming tool and can manufacturing apparatus

Abstract

To provide a screw forming tool and a can manufacturing apparatus capable of reducing the load on a bearing member that rotatably supports an outer roller, extending the service life of the bearing member and maintaining excellent machining accuracy of screw forming.SOLUTION: A screw forming tool 30 for performing screw forming on an opening of a cylindrical can W, comprises: a core roller 33 inserted into the opening of the can W along an axial direction in which the central axis C of the screw forming tool 30 extends; an outer roller 36 disposed on the outer side in the radial direction of the opening of the can W, sandwiches the peripheral wall of the opening together with the core roller 33 and is rotated around the central axis C; a bearing member 37 that rotatably cantilevers a roller shaft 36b of the outer roller 36; an outer block body 38 in which the bearing member 37 is disposed; and a support roller 39 which extends in the axial direction from the outer block body 38, faces the outer roller 36 with a gap from the outer side in the radial direction or is in contact therewith.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a screw forming tool and a can manufacturing apparatus.

Background Art

[0002] Conventionally, there is known a bottle can manufacturing apparatus (hereinafter sometimes referred to as a can manufacturing apparatus) that manufactures a bottle can (a can with a screw) by performing various processes on the opening of a cylindrical can (DI can) as shown in Patent Document 1 below.

[0003] The can manufacturing apparatus includes a holding table (turn table), a processing table (die table), a table indexing mechanism, and a crank mechanism. The holding table has a plurality of chucks that hold a plurality of cans. The processing table is disposed to face the holding table from the axial direction of the table. The processing table has a plurality of processing tools for performing processing on each can held by the holding table. The table indexing mechanism intermittently rotates and moves the holding table relative to the processing table around the table axis. The crank mechanism reciprocates the processing table relative to the holding table in the table axis direction.

[0004] The plurality of chucks of the holding table are arranged side by side around the outer periphery of the holding table around the table axis. Each can is held by each chuck in a posture with the opening facing the processing table side. The plurality of processing tools of the processing table are arranged side by side around the outer periphery of the processing table around the table axis. The plurality of processing tools include a plurality of die processing tools and a plurality of rotary processing tools. The plurality of die processing tools perform various die processes such as drawing (diameter reduction) and diameter expansion on the opening of the can. The plurality of rotary processing tools perform various rotary processes such as trimming, screw forming, curling, and slot (curling flattening) on the opening of the can.

[0005] The holding table and the processing table are repeatedly moved closer to and away from each other in the table axis direction by a crank mechanism, and are intermittently rotated relative to each other around the table axis by a table indexing mechanism. Specifically, the processing table repeatedly moves closer to and away from the holding table in the table axis direction, and during one stroke (reciprocating movement) of this approach and separation, the holding table rotates by a predetermined amount around the table axis relative to the processing table (intermittent rotation).

[0006] And for each stroke in which the tables approach and separate from each other, a predetermined process is performed on the can by a processing tool, and the can is moved to the processing position by the next processing tool. By repeating this operation, sequential processing is performed on the cans held by the holding table by a plurality of processing tools provided on the processing table, and when the processing by all the processing tools is completed, a bottle can having a predetermined shape is obtained.

[0007] Patent Document 1 discloses a screw forming processing tool capable of improving the dimensional stability of a screw portion formed in the opening (base portion) of a can and improving the re-sealing operability.

[0008] The screw forming processing tool includes a mandrel roller inserted into the inside of the opening of the can and an outer roller disposed outside the opening. During the forming of the can, the mandrel roller and the outer roller sandwich the peripheral wall of the opening, and while each roller rotates around its roller axis and revolves around the can axis, screw forming processing is performed on the peripheral wall of the opening.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] During screw forming, the follower roller receives a large load directed outward in the can diameter direction perpendicular to the can axis. In particular, in recent years, as the cans are being made thinner, the load on the follower roller has been increasing. For this reason, there has been a problem that the load on the bearing member that rotatably supports the follower roller is large, and the bearing member is likely to be damaged early. Specifically, since the roller shaft of the follower roller is cantilevered by the bearing member, the roller shaft is likely to tilt when receiving a large load, and the load on the bearing member is also large.

[0011] An object of the present invention is to provide a screw forming tool and a can manufacturing apparatus that can reduce the load on the bearing member that rotatably supports the follower roller, extend the component life of the bearing member, and maintain good processing accuracy of screw forming.

Means for Solving the Problems

[0012] In order to solve the above problems, the present invention provides the following means.

[0013] 〔Aspect 1 of the Present Invention〕 A screw forming tool for performing screw forming on the opening of a cylindrical can, comprising: a mandrel roller inserted into the opening along the axial direction in which the central axis of the screw forming tool extends; an outer roller disposed radially outside the opening, sandwiching the peripheral wall of the opening together with the mandrel roller, and rotated around the central axis; a bearing member that rotatably cantilevers the roller shaft of the outer roller; an outer block body in which the bearing member is disposed; and a support roller extending axially from the outer block body, facing the outer roller with a gap or in contact therewith from the radially outer side.

[0014] According to the screw forming tool of the present invention and the can manufacturing apparatus equipped with the same, during screw forming, when the outer roller receives a large load directed radially outward (outward in the can diameter direction orthogonal to the can axis) orthogonal to the central axis of the screw forming tool, the support roller supports the outer roller from the radially outer side. Thereby, it is possible to suppress the inclination of the roller shaft of the outer roller.

[0015] Especially in recent years, with the trend of making cans thinner, the load on the outer roller tends to increase further. However, according to the present invention, the load on the bearing member that rotatably supports the outer roller cantilever can be stably reduced to a small value. For this reason, breakage of the bearing member can be prevented. In addition, since the occurrence of screw forming defects associated with the inclination of the roller shaft of the outer roller can be suppressed, the processing accuracy of screw forming can be stably improved.

[0016] As described above, according to the present invention, the load on the bearing member that rotatably supports the outer roller can be reduced, the component life of the bearing member can be extended, and the processing accuracy of screw forming can be maintained well.

[0017] 〔Aspect 2 of the present invention〕 The screw forming tool according to Aspect 1, wherein a pair of the support rollers are provided at intervals around the roller central axis of the outer roller.

[0018] In this case, the pair of support rollers support the outer roller from the radially outer side respectively. For this reason, it is more stably suppressed that the roller shaft of the outer roller bends (inclines) under the load.

[0019] 〔Aspect 3 of the present invention〕 A support shaft for supporting the outer block body, and a cam mechanism for rotating the outer block body around the support shaft, wherein, when the outer roller is viewed from the roller axial direction in which the roller central axis extends, the outer roller is perpendicular to an imaginary straight line passing through the center of the support shaft and the roller central axis, and when an imaginary perpendicular line passing through the roller central axis is defined, the pair of support rollers are arranged on both sides with the imaginary perpendicular line interposed therebetween, and a predetermined angular difference is provided between a first angle formed between an imaginary straight line passing through the center of one of the pair of support rollers and the roller central axis and the imaginary perpendicular line, and a second angle formed between an imaginary straight line passing through the center of the other of the pair of support rollers and the roller central axis and the imaginary perpendicular line. The thread forming tool according to aspect 2.

[0020] In this case, during the thread forming process, the outer block body is rotated around the support shaft by the cam mechanism, and thereby the outer roller presses the peripheral wall of the opening of the can to perform the thread forming process. As in the above configuration, when a predetermined angular difference is provided between the first angle and the second angle, when the outer roller rotates around the support shaft together with the outer block body and receives a reaction force (load) by performing the thread forming process, it becomes possible to equalize the loads acting on the pair of support rollers via the outer roller. That is, by appropriately setting the predetermined angular difference, it is possible to greatly suppress the variation in the loads acting on the pair of support rollers, suppress damage to the support rollers, and maintain their functions well.

[0021] 〔Aspect 4 of the present invention〕 The thread forming tool according to any one of aspects 1 to 3, further comprising an adjustment mechanism capable of adjusting the distance between the support roller and the outer roller.

[0022] In this case, by adjusting the distance between the support roller and the outer roller by the adjustment mechanism, the support roller can more stably support the outer roller from the radially outer side during the thread forming process. Therefore, the above-described operational effects according to the present invention are more stably achieved.

[0023] [Aspect 5 of the present invention] A can manufacturing apparatus comprising a holding table that is intermittently rotated about a table axis, and a processing table that reciprocates in the table axis direction with respect to the holding table, wherein the holding table has a plurality of chucks for holding a plurality of cans, the processing table has a plurality of processing tools for processing each of the cans held by each of the chucks, the plurality of processing tools include a plurality of die processing tools and a plurality of rotary processing tools, and at least one of the plurality of rotary processing tools is the thread forming processing tool according to any one of Aspects 1 to 4. [Advantages of the invention]

[0024] According to the thread forming processing tool and the can manufacturing apparatus of the above aspect of the present invention, it is possible to reduce the load on the bearing member that rotatably supports the outer roller, extend the component life of the bearing member, and maintain good processing accuracy of the thread forming processing. [Brief description of the drawings]

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0026] A can manufacturing apparatus 1 according to an embodiment of the present invention and a screw forming tool 30 will be described with reference to the drawings. As shown in FIGS. 1 and 2, the can manufacturing apparatus 1 of the present embodiment is a so-called bottle necker (bottle can manufacturing apparatus) that manufactures a bottle can (product can) P having a predetermined shape by performing a plurality of types of forming processes including die processing and rotational processing on a cylindrical can (intermediate formed body can) W as a workpiece.

[0027] The can W supplied to the can manufacturing apparatus 1 as a workpiece is a DI can that has been subjected to processes such as DI (Drawing & Ironing) processing, printing, and painting in a previous process than the can manufacturing apparatus 1. The DI can is formed into a bottomed cylindrical shape by performing a capping process (drawing process), a DI process (drawing and ironing process), a trimming process, a printing process, a painting process, etc. on a disc-shaped blank punched from an aluminum alloy plate.

[0028] The can W includes a circumferential wall (can body) having a cylindrical shape and a bottom wall (can bottom) having a generally disc shape. In the present embodiment, the central axis of the can W is referred to as the can axis, and the direction in which the can axis extends is referred to as the can axis direction. As shown in FIG. 3, in the can manufacturing apparatus 1, a bottle necking process is performed on the opening of the can W having a bottomed cylindrical shape, whereby a base portion 101 and a shoulder portion 102 are formed. The base portion 101 is the minimum diameter portion of the circumferential wall of the can W. The shoulder portion 102 is disposed between the body portion 103, which is the maximum diameter portion of the circumferential wall of the can W, and the base portion 101, and has a tapered shape in which the diameter gradually decreases as it goes from the body portion 103 to the base portion 101 along the can axis direction.

[0029] The bottle can P manufactured by processing the can W by the can manufacturing apparatus 1 is filled with contents such as beverages in a subsequent process than the can manufacturing apparatus 1, and is sealed by screwing a cap onto the screw portion of the base portion 101.

[0030] As shown in FIGS. 1 and 2, the can manufacturing apparatus 1 includes an apparatus main body 4, a holding table 3, a processing table 2, a shaft portion 5, a crank mechanism 8, a drive motor 11, a table index mechanism 9, a supply wheel 10, a discharge wheel 14, a wheel index mechanism 15, and a conveying means 12.

[0031] For the processing table 2 and the holding table 3, each table axis TA, which is the central axis of each, extends in the horizontal direction, and these table axes TA are arranged coaxially with each other. The processing table 2 and the holding table 3 are arranged side by side in the direction in which the table axis TA extends and face each other.

[0032] In the present embodiment, the direction in which the table axis TA extends is referred to as the table axis direction. In each figure, the table axis direction corresponds to the X-axis direction. Of the table axis direction, the direction from the processing table 2 toward the holding table 3 (+X side) is referred to as one side of the table axis direction, and the direction from the holding table 3 toward the processing table 2 (-X side) is referred to as the other side of the table axis direction. Note that the table axis direction may be referred to as the front-rear direction. In this case, one side (+X side) of the table axis direction corresponds to the rear side, and the other side (-X side) of the table axis direction corresponds to the front side.

[0033] Also, the direction orthogonal to the table axis TA is referred to as the table radial direction. Of the table radial direction, the direction approaching the table axis TA is referred to as the inner side of the table radial direction, and the direction away from the table axis TA is referred to as the outer side of the table radial direction. Also, the direction of orbiting around the table axis TA is referred to as the table circumferential direction.

[0034] The apparatus main body 4 supports the holding table 3, the processing table 2, the shaft portion 5, the crank mechanism 8, the table index mechanism 9, the drive motor 11, the supply wheel 10, the discharge wheel 14, and the wheel index mechanism 15. The conveying means 12 extends outside the apparatus main body 4.

[0035] Although detailed illustrations are omitted, the apparatus main body 4 has, for example, a base, a frame attached to the base, and an exterior member that covers the base and the frame. The base is installed on the floor of a facility such as a factory. The frame is assembled on the base and fixed to the base by fastening members such as bolts or welding. The exterior member has a housing shape and includes a plurality of plate-like members. A part of the exterior member is a door portion that can be opened and closed, and is opened and closed during maintenance of the components of the apparatus.

[0036] The holding table 3 is called, for example, a turntable or an index table. The holding table 3 has a circular ring shape. The holding table 3 is, for example, a circular ring-shaped or disc-shaped table with a large diameter (for example, a radius of 650 mm or more).

[0037] On the outer peripheral portion of the surface facing the other side (-X side) in the table axis direction of the holding table 3, a plurality of chucks 7 are provided at equal pitches along the table circumferential direction. That is, the holding table 3 has a plurality of chucks 7 arranged side by side in the circumferential direction of the holding table 3 on the outer peripheral portion of the holding table 3. The plurality of chucks 7 hold a plurality of cans W.

[0038] Specifically, the bottom of each can W is held by each chuck 7. The can W held by the chuck 7 has its opening facing the other side (-X side) in the table axis direction and faces the processing table 2. The holding table 3 is intermittently rotated in the circumferential direction of the table by a table indexing mechanism 9. That is, the holding table 3 holds a plurality of cans W and is intermittently rotated around the table axis TA.

[0039] In the present embodiment, the direction in which the holding table 3 is intermittently rotated with respect to the processing table 2 in the circumferential direction of the table is called the holding table rotation direction R1, and the rotation direction opposite to this is called the direction opposite to the holding table rotation direction R1 or the reverse holding table rotation direction.

[0040] Note that the holding table rotation direction R1 is the same as the direction in which a plurality of machining tools 6 (described later) provided on the machining table 2 are arranged in the circumferential direction of the table in the order of machining the cans W. Therefore, the holding table rotation direction R1 can be described as the downstream side (or simply the machining order direction) in the machining order of the cans W, and the direction opposite to the holding table rotation direction R1 (the reverse holding table rotation direction) can be described as the upstream side in the machining order of the cans W.

[0041] The machining table 2 is called, for example, a die table. The machining table 2 has a circular annular shape. The machining table 2 is, for example, a circular ring-shaped or disc-shaped table with a large diameter. The diameter dimension (outer diameter dimension) of the machining table 2 is substantially the same as the diameter dimension of the holding table 3.

[0042] The machining table 2 is supported by the apparatus main body 4 via the shaft portion 5. The shaft portion 5 is fixed to the machining table 2 and extends in the table axis direction around the table axis TA. The shaft portion 5 penetrates the holding table 3 in the table axis direction. The shaft portion 5 is movable in the table axis direction with respect to the holding table 3. The shaft portion 5 is slidably supported by the apparatus main body 4 in the table axis direction, and one end (the +X side) of the shaft portion 5 in the table axis direction is connected to a connecting rod 18 (described later) of the crank mechanism 8.

[0043] The machining table 2 is arranged to face the holding table 3 from the other side (-X side) in the table axis direction. The machining table 2 is reciprocated in the table axis direction with respect to the holding table 3 by the crank mechanism 8.

[0044] The machining table 2 has a plurality of machining tools 6 for machining each can W held by each chuck 7. The plurality of machining tools 6 are arranged side by side in the circumferential direction of the table on the outer peripheral portion of the machining table 2. Specifically, the plurality of machining tools 6 are arranged at equal pitches along the circumferential direction of the outer peripheral portion of the machining table 2, and are respectively arranged to face a plurality of cans W held by the holding table 3 from the other side in the table axis direction. The plurality of machining tools 6 are different in type from each other.

[0045] As shown in FIG. 1, the central axis (tool central axis) C of each processing tool 6 extends parallel to the table axis TA. In the present embodiment, the direction in which the central axis C of the processing tool 6 extends is referred to as the axial direction. The axial direction is the same direction as the table axis direction and corresponds to the X-axis direction in each figure. In the present embodiment, one side of the axial direction corresponds to one side (+X side) of the table axis direction, and the other side of the axial direction corresponds to the other side (-X side) of the table axis direction. Note that the axial direction may be rephrased as the front-rear direction. In this case, one side (+X side) of the axial direction corresponds to the rear side, and the other side (-X side) of the axial direction corresponds to the front side.

[0046] Also, the direction orthogonal to the central axis C is referred to as the radial direction. Among the radial directions, the direction approaching the central axis C is referred to as the inner radial direction, and the direction away from the central axis C is referred to as the outer radial direction. Further, the direction of orbiting around the central axis C is referred to as the circumferential direction.

[0047] Note that the axial direction may be rephrased as the tool axis direction for the purpose of distinguishing it from the table axis direction. The radial direction may be rephrased as the tool radial direction for the purpose of distinguishing it from the table radial direction. The circumferential direction may be rephrased as the tool circumferential direction for the purpose of distinguishing it from the table circumferential direction.

[0048] Also, in the present embodiment, when explaining a member, the axial direction, radial direction, and circumferential direction based on the central axis of a member other than the processing tool 6 (central axis other than the central axis C) may be used. In this case, it is explained by appropriately supplementing as necessary which member's central axis the direction is based on.

[0049] The central axis C of the processing tool 6, the central axis of the chuck 7 facing the processing tool 6, and the can axis of the can W held by this chuck 7 are arranged coaxially with each other during processing of the can W (see FIG. 3). Each processing tool 6 faces each can W from the other side of the axial direction (the other side of the tool axis direction, that is, the -X side). Then, with the central axis of the chuck 7 and the can axis of the can W coinciding with the central axis C of the processing tool 6, the can W is processed by the processing tool 6.

[0050] Although not particularly shown, the processing table 2 has mounting holes that penetrate the processing table 2 in the table axis direction (X-axis direction). A plurality of mounting holes are provided in the processing table 2. The plurality of mounting holes are arranged side by side in the circumferential direction of the table on the outer peripheral portion of the processing table 2. A plurality (a plurality of types) of processing tools 6 are mounted in each mounting hole in the order of processing on the can W along the holding table rotation direction R1.

[0051] The plurality of processing tools 6 include a plurality of die processing tools and a plurality of rotary processing tools. In the present embodiment, the die processing tools and the rotary processing tools are detachably mounted in the plurality of mounting holes of the processing table 2 in the order of processing on the can W. Note that an oiling tool for attaching oil to the processing planned portion of the can W may be detachably mounted in one or more of the plurality of mounting holes.

[0052] The plurality of die processing tools move in the axial direction (can axis direction) with respect to the can W, and perform various die processes such as drawing (diameter reduction process) and diameter expansion process on the opening of the can W. One type (predetermined) of die process is performed on the can W by one die processing tool.

[0053] The plurality of rotary processing tools perform various rotary processes such as trimming, thread forming, curling, and slot (curling flattening) processes on the opening of the can W by a rotational movement that moves in the circumferential direction (around the can axis) with respect to the can W. One type (predetermined) of rotary process is performed on the can W by one rotary processing tool.

[0054] FIG. 3 shows a thread forming processing tool 30 as an example of the rotary processing tool of the present embodiment. That is, at least one of the plurality (a plurality of types) of rotary processing tools is the thread forming processing tool 30 of the present embodiment. The detailed configuration of the thread forming processing tool 30 will be described separately later.

[0055] As shown in Fig. 1, the crank mechanism 8 reciprocates the machining table 2 in the table axis direction with respect to the holding table 3. The crank mechanism 8 includes a drive shaft 16 to which rotation (rotary driving force) from a drive motor 11 is input, a crank shaft 17 connected to the drive shaft 16 and rotated about the axis O of the drive shaft 16 as the drive shaft 16 rotates, and a connecting rod 18 connecting the crank shaft 17 and the shaft portion 5. The crank mechanism 8 converts the rotational motion about the axis O input from the drive motor 11 to the drive shaft 16 into a linear motion in the table axis direction and outputs it to the shaft portion 5. The drive motor 11 is, for example, an inverter motor or the like.

[0056] The table indexing mechanism 9 rotates and stops (intermittently rotates) the holding table 3 in the circumferential direction of the table every one stroke of the reciprocating movement along the table axis direction of the machining table 2. The table indexing mechanism 9 has a structure for intermittently rotating the holding table 3 about the table axis TA with respect to the machining table 2 according to the crank angle around the drive shaft 16 of the crank mechanism 8.

[0057] Therefore, the holding table 3 and the machining table 2 are repeatedly moved closer to and away from each other in the table axis direction by the crank mechanism 8, and are intermittently rotated relative to each other in the circumferential direction of the table by the table indexing mechanism 9. Specifically, the machining table 2 moves closer to and away from the holding table 3 in the table axis direction, and during one stroke (reciprocating movement) of this approach and separation, the holding table 3 rotates (intermittently rotates) by a predetermined amount in the circumferential direction of the table with respect to the machining table 2.

[0058] Then, for each stroke in which the machining table 2 and the holding table 3 approach and separate, predetermined machining is performed on the can W held by the chuck 7 of the holding table 3 by each machining tool 6 of the machining table 2, and the holding table 3 moves the can W to the downstream side (holding table rotation direction R1) of the machining sequence to the machining position by the next (another) machining tool 6. By repeating this operation, the cans W held by the holding table 3 are sequentially processed by a plurality of processing tools 6 provided on the processing table 2, and when the processing by all the processing tools 6 is completed, a bottle can P having a predetermined shape is obtained.

[0059] As shown in FIG. 2, the supply wheel 10 supplies the cans W to the holding table 3. The supply wheel 10 is called an infeed wheel and has a substantially cylindrical shape. The supply wheel 10 receives the cans W supplied from the outside of the can manufacturing apparatus 1 (the previous process than the can manufacturing apparatus 1) to the shooter 13 and transfers the cans W to the holding table 3. The supply wheel 10 has a wheel axis SA which is its central axis extending parallel to the table axis TA and is supported by the apparatus main body 4. The supply wheel 10 is rotated in the wheel rotation direction R2 about the wheel axis SA.

[0060] The discharge wheel 14 discharges the processed cans W (bottle cans P) from the holding table 3. The discharge wheel 14 is called a discharge wheel and has a substantially cylindrical shape. The discharge wheel 14 receives the cans W (bottle cans P) processed by the can manufacturing apparatus 1 from the holding table 3 and transfers (discharges) them to the conveying means 12. The conveying means 12 conveys the bottle cans P toward the outside of the can manufacturing apparatus 1 (the subsequent process than the can manufacturing apparatus 1). The discharge wheel 14 has a wheel axis DA which is its central axis extending parallel to the table axis TA and is supported by the apparatus main body 4. The discharge wheel 14 is rotated in the wheel rotation direction R3 about the wheel axis DA.

[0061] The supply wheel 10 has a plurality of concave pockets 23 capable of holding the peripheral wall of the can W. The plurality of pockets 23 are arranged at equal pitches in the circumferential direction of the wheel around the wheel axis SA on the outer peripheral portion of the supply wheel 10. Further, the discharge wheel 14 has a plurality of concave pockets 24 capable of holding the peripheral wall of the can W (bottle can P). The plurality of pockets 24 are arranged at equal pitches in the circumferential direction of the wheel around the wheel axis DA on the outer peripheral portion of the discharge wheel 14. In FIG. 2, the illustration of each of the pockets 23, 24 is partially omitted.

[0062] These pockets 23, 24 are formed in a concave curved surface shape in which a cross section perpendicular to the wheel axes SA, DA is a concave arc shape corresponding to the fact that the peripheral wall of the can W is cylindrical. Further, suction holes communicating with an air suction source (not shown) are opened on the inner surfaces of the pockets 23, 24. The pockets 23, 24 can hold the can W by the air suction force of the air suction source acting on the peripheral wall of the can W through the suction holes.

[0063] The wheel indexing mechanism 15 intermittently rotates and moves the supply wheel 10 and the discharge wheel 14 around the respective wheel axes SA, DA in synchronization with the intermittent rotation of the holding table 3 around the table axis TA.

[0064] Specifically, the supply wheel 10 and the discharge wheel 14 are intermittently rotated in wheel rotation directions R2, R3 (clockwise around the respective wheel axes SA, DA in the example of FIG. 2), which are reverse rotations to the holding table rotation direction R1 (counterclockwise around the table axis TA in the example of FIG. 2), by the wheel indexing mechanism 15.

[0065] When the supply wheel 10 rotates intermittently and the can W held in the pocket 23 of the supply wheel 10 is arranged at a position overlapping with the chuck 7 of the holding table 3 when viewed from the table axis direction (directly above the chuck 7), a pushing portion (not shown) provided on the processing table 2 pushes this can W toward one side (+X side) in the table axis direction. Thereby, the can W is transferred from the pocket 23 to the chuck 7 and held by the chuck 7.

[0066] Also, the can W held by the chuck 7 of the holding table 3 is transferred in the holding table rotation direction R1 for each stroke of the processing table 2. After all the processing is completed, when it is arranged at a position overlapping with the pocket 24 of the discharge wheel 14 (directly below the pocket 24) as viewed from the table axis direction, the extrusion piston provided in the chuck 7 pushes out this can W (the bottle can P of the product subjected to all the processing) toward the other side (-X side) in the table axis direction. As a result, the can W (bottle can P) is transferred from the chuck 7 to the pocket 24 and held by the pocket 24. In FIG. 3, the chuck 7 is shown in a simplified manner, and the illustration of the extrusion piston and the like is omitted.

[0067] The bottle can P held by the pocket 24 is transferred around the wheel axis DA as the discharge wheel 14 rotates intermittently, is released from the pocket 24, and is transferred to the conveying means 12.

[0068] The drive motor 11, the crank mechanism 8, the table index mechanism 9, and the wheel index mechanism 15 are mechanically connected to each other so as to be synchronizable by, for example, gears, belts, joints, etc. That is, by the rotational driving force of the drive motor 11, the crank mechanism 8, the table index mechanism 9, and the wheel index mechanism 15 are driven in synchronization with each other.

[0069] Next, with reference to FIGS. 3 to 8, the screw forming processing tool 30 of the present embodiment will be described. The screw forming processing tool 30 is one of a plurality of rotary processing tools provided in the can manufacturing apparatus 1, and performs screw forming processing on the opening (base portion 101) of the cylindrical can W. Specifically, for example, as shown in the above Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2016-036843), the screw forming processing tool 30 sandwiches the peripheral wall of the base portion 101 of the can W with a pair of rollers from the radially inner side and the radially outer side, and presses it over the entire circumference around the can axis from the radially inner side and the outer side, thereby performing processing for forming a screw portion.

[0070] As shown in FIG. 3, the thread forming tool 30 includes a first housing 31, a second housing 32, a core roller 33, a core bearing member (not shown), a core block body 34, a core support shaft (not shown), a core cam mechanism 35, an outer roller 36, an outer bearing member (bearing member) 37, an outer block body 38, a support roller 39, an outer support shaft (support shaft. Not shown), an outer cam mechanism (cam mechanism) 40, and an adjustment mechanism 41.

[0071] Note that the first housing 31, the second housing 32, the core roller 33, the core block body 34, the core support shaft, the core cam mechanism 35, the outer roller 36, the outer block body 38, the outer support shaft, and the outer cam mechanism 40, etc. have the same basic structure as the respective constituent members described in the above Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-036843). Therefore, detailed descriptions of the above members may be omitted below.

[0072] The first housing 31 is disposed between the processing table 2 and the holding table 3 in the axial direction. The first housing 31 is rotatably attached around the central axis C to the mounting hole of the processing table 2 via a bearing member (not shown). The first housing 31 has a cylindrical shape centered on the central axis C and extends in the axial direction. Specifically, the first housing 31 has a toped cylindrical shape and has a peripheral wall and a top wall. The end on one side (+X side) in the axial direction of the peripheral wall of the first housing 31 is open, and the end on the other side (-X side) in the axial direction is closed by the top wall.

[0073] The second housing 32 is disposed within the first housing 31. The second housing 32 is rotatably supported around the central axis C by the tool spindle 25. The tool spindle 25 is inserted into the mounting hole of the processing table 2 and extends in the axial direction. The tool spindle 25 is connected to a rotary processing motor (not shown) provided on the processing table 2 via a transmission member such as a belt.

[0074] The second housing 32 is cylindrical about the central axis C and extends in the axial direction. Specifically, the second housing 32 has a capped cylindrical shape and has a peripheral wall and a top wall. The end on one axial side (+X side) of the peripheral wall of the second housing 32 is open, and the end on the other axial side (-X side) is closed by the top wall. The first housing 31 and the second housing 32 are coaxially arranged with the central axis C as a common axis and are relatively movable in the axial direction.

[0075] The core block body 34 is supported by the second housing 32 via a core support shaft (not shown). That is, the core support shaft supports the core block body 34. The core support shaft extends from the top wall of the second housing 32 toward one axial side (+X side). The core block body 34 is rotatable about the central axis of the core support shaft with respect to the second housing 32.

[0076] The core roller 33 is rotatably supported by the core block body 34 via a core bearing member (not shown). The core roller 33 protrudes from the core block body 34 toward one axial side (+X side) and extends in the axial direction.

[0077] The core roller 33 is inserted into the opening (cap portion 101) of the can W along the axial direction in which the central axis C of the screw forming tool 30 extends. The core roller 33 has a core forming portion 33a and a roller shaft 33b.

[0078] The core forming portion 33a is inserted into the cap portion 101 of the can W, contacts the peripheral wall of the cap portion 101 from the radially inner side, and performs screw forming. The roller shaft 33b has a smaller diameter than the core forming portion 33a and extends from the core forming portion 33a toward the other axial side (-X side). The roller shaft 33b is supported by the core block body 34 via a core bearing member (not shown). Specifically, the roller shaft 33b is rotatable about the roller central axis of the core roller 33 and is supported by the core block body 34.

[0079] The core cam mechanism 35 has a cam 35a and a cam follower 35b. The cam 35a is disposed on the inner peripheral surface of the peripheral wall of the first housing 31. The cam 35a has an inclined surface shape that extends radially inward as it goes toward the other axial side (-X side). The cam follower 35b is disposed at the radially outer end portion of the core block body 34. The cam follower 35b is capable of rolling on the cam 35a.

[0080] In the process of the processing table 2 approaching and moving toward one side in the table axial direction (one axial side, +X side) with respect to the holding table 3, the second housing 32 is restricted from moving further toward one axial side from a predetermined position in the axial direction by the function of a stopper member (not shown) or the like. At this time, since the first housing 31 moves further toward one axial side, the second housing 32 and the first housing 31 move relative to each other in the axial direction.

[0081] Thereby, while the cam follower 35b rolls on the cam 35a of the core cam mechanism 35, it is displaced radially inward. Due to this displacement of the cam follower 35b, the core block body 34 is pushed radially inward, and the core block body 34 is rotated around the central axis of the core support shaft. Along with the rotation of the core block body 34, the core roller 33 contacts the peripheral wall of the opening (base portion 101) of the can W from the radially inner side and presses the peripheral wall radially outward.

[0082] The outer block body 38 is supported by the second housing 32 via an outer support shaft (not shown). That is, the outer support shaft (support shaft) supports the outer block body 38. The outer support shaft extends from the top wall of the second housing 32 toward one axial side (+X side). The outer block body 38 is rotatable around the central axis of the outer support shaft with respect to the second housing 32.

[0083] The outer roller 36 is rotatably supported by the outer block body 38 via the outer bearing member 37. That is, the outer bearing member 37 is disposed in the outer block body 38. The outer roller 36 protrudes from the outer block body 38 toward one axial side (+X side) and extends in the axial direction. That is, the roller central axis A of the outer roller 36 extends parallel to the central axis C of the thread forming tool 30.

[0084] Further, the outer roller 36, the outer support shaft, the inner roller 33, and the inner support shaft each have a gear (not shown). The gears of the outer roller 36, the outer support shaft, the inner roller 33, and the inner support shaft are meshed with each other so as to be rotatable in synchronization (for details, refer to FIG. 7 and the like of the above Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-036843)).

[0085] The outer roller 36 is disposed radially outside the opening (base portion 101) of the can W. The outer roller 36 has an outer forming portion 36a and a roller shaft 36b.

[0086] The outer forming portion 36a contacts the peripheral wall of the base portion 101 of the can W from the radially outside and performs thread forming. The roller shaft 36b has a smaller diameter than the outer forming portion 36a and extends from the outer forming portion 36a toward the other axial side (-X side). The roller shaft 36b is supported by the outer block body 38 via the outer bearing member 37. Specifically, the roller shaft 36b is rotatable around the roller central axis A of the outer roller 36 and is supported by the outer block body 38.

[0087] As shown in FIGS. 3 and 7, a plurality of outer bearing members 37 are provided side by side in the axial direction. In the present embodiment, a pair of outer bearing members 37 are provided at intervals in the axial direction. The outer bearing member (bearing member) 37 rotatably cantilever supports the roller shaft 36b of the outer roller 36.

[0088] Here, the "cantilever support" in the present embodiment means a mode in which the outer bearing member 37 is provided only on the other axial side (-X side) with respect to the outer forming portion 36a of the outer roller 36. Specifically, when the outer bearing members 37 are provided on both sides (one axial side (+X side) and the other axial side (-X side)) with the outer forming portion 36a interposed therebetween in the axial direction, it is "double support", and when the outer bearing member 37 is provided only on one side (the other axial side (-X side)) of the outer forming portion 36a in the axial direction, it is "cantilever support".

[0089] The outer cam mechanism 40 has a cam 40a and a cam follower 40b. The cam 40a is disposed on the inner peripheral surface of the peripheral wall of the first housing 31. The cam 40a has an inclined surface shape extending radially inward as it goes toward the other axial side (-X side). The cam follower 40b is disposed at the radially outer end portion of the outer block body 38. The cam follower 40b is capable of rolling on the cam 40a.

[0090] In the process of the processing table 2 approaching and moving toward one side in the table axial direction (the one axial side, +X side) with respect to the holding table 3, the second housing 32 is restricted from further moving toward one axial side from a predetermined position in the axial direction by the function of a stopper member (not shown) or the like. At this time, since the first housing 31 further moves toward one axial side, the second housing 32 and the first housing 31 relatively move in the axial direction.

[0091] As a result, the cam follower 40b is displaced radially inward while rolling on the cam 40a of the outer cam mechanism 40. Due to this displacement of the cam follower 40b, the outer block body 38 is pushed radially inward, and the outer block body 38 is rotated around the central axis of the outer support shaft. That is, the outer cam mechanism (cam mechanism) 40 rotates the outer block body 38 around the outer support shaft (support shaft). Along with the rotation of the outer block body 38, the outer roller 36 contacts the peripheral wall of the opening (base portion 101) of the can W from the radially outer side and presses the peripheral wall radially inward.

[0092] As described above, the peripheral wall of the base portion 101 of the can W is sandwiched and pressed from the radially inner side and the radially outer side by the inner roller 33 and the outer roller 36. In this state, when the tool spindle 25 is rotationally driven around the central axis C by the rotary machining motor, the inner roller 33 and the outer roller 36 rotate (self-rotate) around their respective roller central axes A while rotating (revolving) around the central axis C of the screw forming tool 30. As a result, a screw portion is formed on the opening (base portion 101) of the can W. That is, the outer roller 36 sandwiches the peripheral wall of the opening of the can W together with the inner roller 33 and is rotated around the central axis C.

[0093] Also, in the process in which the machining table 2 moves away from the holding table 3 toward the other side in the table axis direction (the other side in the axis direction, the -X side), the opening (base portion 101) of the can W is released from the inner roller 33 and the outer roller 36 in the reverse order of the above-described order, and the inner roller 33 is withdrawn from the inside of the opening of the can W toward the other side in the axis direction.

[0094] As shown in FIGS. 3 to 8, the support roller 39 extends from the outer block body 38 toward one side in the axis direction (+X side), faces or contacts the outer roller 36 with a gap therebetween from the radially outer side. In other words, the outer roller 36 is arranged so as to be sandwiched between the inner roller 33 and the support roller 39 in the radial direction. The central axes (B1, B2) of the support roller 39 extend parallel to the roller central axis A of the outer roller 36 and the central axis C of the screw forming tool 30.

[0095] The support roller 39 has a roller portion 39a that faces or contacts the outer circumferential surface of the outer forming portion 36a of the outer roller 36 with a gap therebetween, and a shaft body 39b that rotatably supports the roller portion 39a around the central axis (B1, B2) of the support roller 39 and is attached to the outer block body 38. In the present embodiment, the roller portion 39a faces or contacts the end portion on the other axial side (-X side) of the outer circumferential surface of the outer forming portion 36a with a gap therebetween. Further, the shaft body 39b supports the roller portion 39a at the end portion on one axial side (+X side) thereof. When providing the gap, the distance between the rollers 39 and 36 is, for example, about 0.05 mm.

[0096] Further, a pair of support rollers 39 are provided at intervals from each other around the roller central axis A of the outer roller 36. Here, what is indicated by reference sign D in FIG. 5 represents the central axis D of an outer support shaft (support shaft) (not shown). Further, reference sign 38a represents an insertion hole 38a that penetrates the outer block body 38 in the axial direction. The outer support shaft is inserted into the insertion hole 38a.

[0097] In the present embodiment, as shown in FIG. 5, when the outer roller 36 is viewed from the roller axial direction in which the roller central axis A extends (that is, viewed from the axial direction), a virtual straight line VL1 passing through the center (central axis D) of the outer support shaft (support shaft) and the roller central axis A is defined, and a virtual perpendicular line VP passing through the roller central axis A is defined. The pair of support rollers 39 are arranged on both sides with the virtual perpendicular line VP interposed therebetween. In the present embodiment, among the pair of support rollers 39, the support roller 39 arranged on the side opposite to the central axis D with respect to the virtual perpendicular line VP in FIG. 5 is referred to as one support roller 39A, and the support roller 39 arranged on the central axis D side with respect to the virtual perpendicular line VP is referred to as the other support roller 39B.

[0098] Also, in FIG. 5, among the pair of support rollers 39A and 39B, the angle formed between the first virtual straight line VL2 passing through the center (central axis B1) of the support roller 39A on the side far from the central axis D and the roller central axis A and the virtual perpendicular line VP is defined as the first angle θ1. Among the pair of support rollers 39A and 39B, the angle formed between the second virtual straight line VL3 passing through the center (central axis B2) of the other support roller 39B close to the central axis D and the roller central axis A and the virtual perpendicular line VP is defined as the second angle θ2. The first angle θ1 and the second angle θ2 are different from each other, and a predetermined angular difference (θ2 - θ1) is provided between the first angle θ1 and the second angle θ2. In the present embodiment, the first angle θ1 is, for example, 22.5°, and the second angle θ2 is, for example, 30°. The angular difference (θ2 - θ1) between the first angle θ1 and the second angle θ2 is, for example, 7.5°.

[0099] The adjustment mechanism 41 is provided on the outer block body 38. The adjustment mechanism 41 can adjust the distance between the support roller 39 and the outer roller 36. As shown in FIG. 8, in the present embodiment, the adjustment mechanism 41 is a male screw member such as a wood screw screwed into the female screw hole of the outer block body 38. The adjustment mechanism 41 is provided in the same number as the number of support rollers 39, and in the present embodiment, a pair of them is provided.

[0100] The tip of the adjustment mechanism 41 is in contact with the shaft body 39b of the support roller 39 from the outer side in the radial direction orthogonal to the central axes B1 and B2 of the support roller 39. In the present embodiment, by adjusting the screwing amount of screwing the adjustment mechanism 41 into the female screw hole, the distance between the roller portion 39a of the support roller 39 and the outer forming portion 36a of the outer roller 36 is adjusted.

[0101] According to the screw forming tool 30 of the present embodiment described above and the can manufacturing apparatus 1 including the same, when the outer roller 36 receives a large load directed outward in the radial direction (outward in the can diameter direction orthogonal to the can axis) orthogonal to the central axis C of the screw forming tool 30 during screw forming, the support roller 39 supports the outer roller 36 from the outer side in the radial direction. Thereby, it is possible to suppress the inclination of the roller shaft 36b of the outer roller 36.

[0102] Particularly in recent years, as the thickness of the can is being reduced, the load on the outer roller tends to increase even more. However, according to the present embodiment, the load on the outer bearing member (bearing member) 37 that rotatably supports the outer roller 36 in a cantilever manner can be stably and significantly suppressed. For this reason, breakage of the outer bearing member 37 can be prevented. Further, since the occurrence of defective thread forming due to the inclination of the roller shaft 36b of the outer roller 36 can be suppressed, the processing accuracy of the thread forming process can be stably enhanced.

[0103] As described above, according to the present embodiment, the load on the outer bearing member (bearing member) 37 that rotatably supports the outer roller 36 can be reduced, the component life of the outer bearing member 37 can be extended, and the processing accuracy of the thread forming process can be favorably maintained.

[0104] Also, in the present embodiment, a pair of support rollers 39 are provided at intervals around the roller central axis A of the outer roller 36. In this case, the pair of support rollers 39 support the outer roller 36 from the radially outer side respectively. For this reason, it is more stably suppressed that the roller shaft 36b of the outer roller 36 bends (tilts) under the load.

[0105] Also, in the present embodiment, as shown in FIG. 5, when viewed from the roller axial direction in which the roller central axis A of the outer roller 36 extends, a first angle θ1 formed between a first virtual straight line VL2 passing through the center (central axis B1) of one support roller 39A and the roller central axis A, and a virtual perpendicular line VP, and a second angle θ2 formed between a second virtual straight line VL3 passing through the center (central axis B2) of the other support roller 39B and the roller central axis A, and the virtual perpendicular line VP, a predetermined angular difference (θ2 - θ1) is provided therebetween.

[0106] During screw forming, while the cam follower 40b rolls on the cam 40a and receives an external force indicated by the arrow F in Fig. 5, the cam follower 40b is displaced radially inward. Along with this, the follower block body 38 is rotated in the rotation direction R around the central axis D of the follower support shaft (support shaft). As a result, the follower roller 36 presses against the peripheral wall of the opening of the can W to perform screw forming.

[0107] At this time, when a predetermined angular difference (θ2 - θ1) is provided between the first angle θ1 and the second angle θ2 as in the above configuration, the follower roller 36 rotates around the follower support shaft together with the follower block body 38. When a reaction force (load) is received by performing screw forming, it becomes possible to equalize the loads acting on the pair of support rollers 39 via the follower roller 36. That is, by appropriately setting the predetermined angular difference (θ2 - θ1), it becomes possible to significantly suppress the variation in the loads acting on the pair of support rollers 39A and 39B, suppress damage to the support rollers 39, and maintain their functions well.

[0108] Further, the screw forming tool 30 of the present embodiment further includes an adjustment mechanism 41 capable of adjusting the distance between the support roller 39 and the follower roller 36. In this case, by adjusting the distance between the support roller 39 and the follower roller 36 by the adjustment mechanism 41, the support roller 39 can more stably support the follower roller 36 from the radially outer side during screw forming. Therefore, the above-described operational effects according to the present embodiment are more stably achieved.

[0109] Note that the present invention is not limited to the foregoing embodiments. For example, as described below, modifications and the like of the configuration are possible without departing from the spirit of the present invention.

[0110] In the foregoing embodiments, the can manufacturing apparatus 1 was exemplified by a bottle can manufacturing apparatus that manufactures a bottle can P by performing various processes on a bottomed cylindrical can W, but the present invention is not limited thereto. The can manufacturing apparatus 1 may be, for example, an aerosol can manufacturing apparatus that manufactures an aerosol can by performing various processes on the can W, or may be a can manufacturing apparatus that manufactures other cans other than bottle cans and aerosol cans. Further, the can W is not limited to a bottomed cylindrical shape, and may be a simple cylindrical shape having a peripheral wall and no bottom wall.

[0111] The present invention may combine the respective configurations described in the foregoing embodiments and modified examples, etc. within a range not departing from the gist of the present invention, and addition, omission, substitution, and other changes of the configuration are possible. Further, the present invention is not limited by the foregoing embodiments, etc., and is limited only by the scope of the claims.

Industrial Applicability

[0112] According to the screw forming tool and the can manufacturing apparatus of the present invention, it is possible to reduce the load on the bearing member that rotatably supports the outer roller, extend the component life of the bearing member, and maintain good processing accuracy in screw forming. Therefore, it has industrial applicability.

Explanation of Reference Numerals

[0113] 1... Can manufacturing apparatus, 2... Processing table, 3... Holding table, 6... Processing tool, 7... Chuck, 30... Screw forming tool, 33... Inner roller, 36... Outer roller, 36b... Roller shaft, 37... Outer bearing member (bearing member), 38... Outer block body, 39, 39A, 39B... Support roller, 40... Outer cam mechanism (cam mechanism), 41... Adjusting mechanism, 101... Base portion (opening of can), A... Roller central axis, B1, B2... Centers of support rollers (central axes), C... Central axis of screw forming tool, TA... Table axis, VL1... Virtual straight line, VL2... First virtual straight line, VL3... Second virtual straight line, VP... Virtual perpendicular, W... Can, θ1... First angle, θ2... Second angle

Claims

1. A thread forming tool for performing thread forming on an opening of a cylindrical can, comprising: a mandrel roller inserted into the opening along an axial direction in which a central axis of the thread forming tool extends; an outer roller disposed radially outside the opening, sandwiching a peripheral wall of the opening together with the mandrel roller, and rotatable about the central axis; a bearing member rotatably supporting one end of a roller shaft of the outer roller; an outer block body in which the bearing member is disposed; a support roller extending axially from the outer block body, facing or contacting the outer roller with a gap therebetween from the radially outer side; a thread forming tool.

2. The thread forming tool according to claim 1, wherein a pair of the support rollers are provided at intervals around a roller central axis of the outer roller. The thread forming tool according to claim 1.

3. a support shaft for supporting the outer block body; a cam mechanism for rotating the outer block body about the support shaft; when viewed from a roller axial direction in which a roller central axis of the outer roller extends, perpendicular to a virtual straight line passing through a center of the support shaft and the roller central axis, and when a virtual perpendicular line passing through the roller central axis is defined, the pair of support rollers are disposed on both sides with the virtual perpendicular line therebetween; a first angle formed between a first virtual straight line passing through a center of one of the pair of support rollers and the roller central axis and the virtual perpendicular line; a predetermined angular difference is provided between the first angle and a second angle formed between a second virtual straight line passing through a center of the other of the pair of support rollers and the roller central axis and the virtual perpendicular line. The thread forming tool according to claim 2.

4. The thread forming tool according to any one of claims 1 to 3, further comprising an adjustment mechanism for adjusting a distance between the support roller and the outer roller. The thread forming tool according to any one of claims 1 to 3.

5. a holding table intermittently rotated about a table axis; a processing table reciprocally moved in a table axial direction with respect to the holding table; the holding table having a plurality of chucks for holding a plurality of cans; the processing table having a plurality of processing tools for processing each of the cans held by each of the chucks; the plurality of processing tools including a plurality of die processing tools and a plurality of rotary processing tools. At least one of the plurality of rotary machining tools is a thread forming machining tool according to any one of claims 1 to 3, A can manufacturing apparatus.

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