JP7499638B2 - Reciprocating linear motion mechanism for can forming device and can forming device - Google Patents

Description

The present invention relates to a reciprocating linear motion mechanism for a can forming device and a can forming device.

Conventionally, bottomed cylindrical DI (Drawing & Ironing) cans are known. DI cans are manufactured by subjecting a circular aluminum alloy blank to cupping, DI, and other processes. In cupping, the blank is drawn into a cup-shaped body. In DI, the cup-shaped body is pressed with a cup holder and drawn and ironed between a punch and a die.

A known example of a can forming device that performs DI processing on a cup-shaped body is described in Patent Document 1. This can forming device uses a reciprocating linear motion mechanism to perform reciprocating linear motion of a punch in a predetermined stroke direction via a ram shaft.

JP 2018-54065 A

Conventional can forming equipment had room for improvement in terms of keeping the external dimensions of the reciprocating linear motion mechanism small.

One of the objectives of the present invention is to provide a reciprocating linear motion mechanism for a can forming device, and a can forming device, that can keep the external dimensions of the reciprocating linear motion mechanism small.

One aspect of the reciprocating linear motion mechanism of the can forming apparatus of the present invention includes a housing having an internal gear centered on a first central axis, a first rotor located inside the housing in a first radial direction perpendicular to the first central axis, a first bearing connecting the housing and the first rotor to be relatively rotatable around the first central axis, a recess recessed from a surface facing one axial side of the first rotor to the other axial side and centered on a second central axis parallel to the first central axis, and a second rotor having an external gear centered on the second central axis and meshing with the internal gear and positioned on one axial side of the first rotor. The housing comprises a rolling body, a convex portion protruding in the other axial direction from a surface facing the other axial direction of the second rotating body and inserted into the concave portion, a second bearing connecting the convex portion and the concave portion so that they can rotate relatively around the second central axis, and a ram shaft connecting portion connected to the second rotating body and capable of reciprocating linear motion along a predetermined direction in the first radial direction , wherein the internal gear is arranged at an end on one axial side of the housing, the first rotating body is accommodated in the housing, and when viewed from a second radial direction perpendicular to the second central axis, the first bearing, the concave portion, the second bearing and the convex portion overlap each other.
Furthermore, one aspect of the can forming apparatus of the present invention comprises a reciprocating linear motion mechanism of the above-mentioned can forming apparatus, a ram shaft extending in the specified direction and having one end connected to the ram shaft connecting portion, a punch arranged on the other end of the ram shaft, a die having a through hole through which the punch is inserted, and a cup holder pressed against the end face of the die into which the through hole opens.

In the present invention, the axial positions of the first bearing, the recess, the second bearing, and the protrusion are the same, so the bulkiness of the axial dimensions of the reciprocating linear motion mechanism can be reduced. In addition, the axial dimensions of the external gear and the internal gear can also be easily reduced. At least the axial external dimensions of the reciprocating linear motion mechanism can be reduced, and the structure can be simplified.

In the reciprocating linear motion mechanism of the can forming device, it is preferable that the internal gear and the external gear are arranged on one axial side of the first bearing, the recess, the second bearing, and the protrusion.

In this case, the structure of the reciprocating linear motion mechanism can be simplified while keeping the external dimensions in the axial direction smaller.

In the reciprocating linear motion mechanism of the can forming device, it is preferable that the internal gear and the external gear are located in an opening on one axial side of the housing.

In this case, the structure of the reciprocating linear motion mechanism can be simplified, while the outer dimensions in the axial direction can be made smaller.
In the reciprocating linear motion mechanism of the can forming apparatus, it is preferable that the first bearing and the second bearing are not on one axial side of the internal gear and the external gear.

According to one embodiment of the reciprocating linear motion mechanism of a can forming device and the can forming device of the present invention, the external dimensions of the reciprocating linear motion mechanism can be kept small.

FIG. 1 is a schematic diagram showing a can forming apparatus according to the present embodiment. FIG. 2 is a perspective view showing a reciprocating linear motion mechanism of the can forming apparatus of this embodiment. FIG. 3 is a cross-sectional view showing a schematic diagram of a reciprocating linear motion mechanism of the can forming apparatus of this embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A can forming apparatus 1 according to one embodiment of the present invention and a reciprocating linear motion mechanism 10 (hereinafter, may be simply referred to as the reciprocating linear motion mechanism 10) of the can forming apparatus 1 will be described with reference to the drawings.
As shown in FIG. 1, the can forming apparatus 1 of this embodiment is a DI can manufacturing apparatus that performs DI processing on a cup-shaped body W, which is a workpiece, to produce a DI can 100.

First, the DI can 100 will be described.
The DI can 100 is a cylindrical shape with a bottom. The DI can 100 is used for can bodies such as two-piece cans and bottle cans in which contents such as beverages are filled and sealed. In the case of a two-piece can, the can body includes the DI can 100 and a disk-shaped can lid that is wrapped and fastened around the open end of the DI can 100. In the case of a bottle can, the can body includes a bottle can body formed by subjecting the DI can 100 to necking and threading, and a cap that is screwed onto the open end of the bottle can body.

The DI can 100 is formed into a bottomed cylindrical shape by subjecting a disk-shaped blank punched out of a plate material such as an aluminum alloy to a cupping process (drawing process) and a DI process (drawing and ironing process). Specifically, in the case of a two-piece can, for example, the DI can 100 is manufactured through a plate material punching process, a cupping process, a DI process, a trimming process, a printing process, a painting process, a necking process, and a flanging process, in that order.

In the process of manufacturing the DI can 100, a blank is drawn (cupped) using a cupping press to form a cup-shaped body W. In other words, the cup-shaped body W is a formed intermediate body produced in the process of transitioning from the blank to the DI can 100 in the cupping process. The cup-shaped body W is a bottomed cylinder with a smaller peripheral wall height (length along the can axis) and a larger diameter than the DI can 100.

Next, the can forming apparatus 1 will be described.
The can forming apparatus 1 is used in the DI process, and performs DI processing, i.e., drawing (redrawing) and ironing, on the cup-shaped body W to form a DI can 100 having a peripheral wall greater in height and a smaller in diameter than the cup-shaped body W. Furthermore, in the DI process, the can forming apparatus 1 forms the bottom of the DI can 100 into a dome shape.

The can forming apparatus 1 includes a reciprocating linear motion mechanism 10, a ram shaft 3 extending in a predetermined direction (hereinafter sometimes referred to as a stroke direction S) in which a ram shaft connecting part 35 (described later) of the reciprocating linear motion mechanism 10 is caused to linearly reciprocate, and having one end connected to the ram shaft connecting part 35, a punch 2 arranged at the other end of the ram shaft 3, a ram bearing 5 supporting the ram shaft 3 so as to be able to reciprocate along the axial direction of a central axis O of the ram shaft 3, a die 8 having a through hole 7 into which the punch 2 is inserted, a cup holder 6 pressed against an end face 9 into which the through hole 7 of the die 8 opens, and a domer 11 that sandwiches the bottom of a DI can 100 between the punch 2 and the domer 11 to form it into a dome shape.
The central axes O of the ram shaft 3, punch 2, ram bearing 5, through hole 7 of the die 8, cup holder 6, and domer 11 are arranged coaxially with one another. In this embodiment, the central axis O, which is the common axis of these members, extends in the horizontal direction.

The can forming device 1 also includes a cup feeder (not shown) that supplies a cup-shaped body W onto the end surface 9 of the die 8, a receiving seat (not shown) that holds the cup-shaped body W on the end surface 9, a can conveying mechanism (not shown) that conveys the formed DI can 100 to the outside of the device, an air discharge mechanism (not shown) that discharges air from an air discharge hole that opens on at least one of the tip surface and the outer peripheral surface of the punch 2 to release the DI can 100 from the punch 2, a cup holder drive mechanism (not shown) that is driven in synchronization with the reciprocating linear motion mechanism 10 and moves the cup holder 6 back and forth in the axial direction of the central axis O with a stroke length different from that of the ram shaft connection part 35 of the reciprocating linear motion mechanism 10, and a drive source (not shown) such as a drive motor.

The reciprocating linear motion mechanism 10 converts a rotational driving force about a first central axis C1 input from a driving source into reciprocating linear motion in a stroke direction S along a central axis O, and outputs the reciprocating linear motion to a ram shaft connecting portion 35. A specific configuration of the reciprocating linear motion mechanism 10 will be described separately later.
The ram shaft 3 has a shaft shape extending along the central axis O. The ram shaft 3 is slidably supported by a pair of ram bearings 5 that are arranged spaced apart from each other in the axial direction of the central axis O.
The punch 2 has a cylindrical or columnar shape extending along a central axis O.

The pair of ram bearings 5 are arranged between the reciprocating linear motion mechanism 10 and the die 8 in the axial direction of the central axis O. Of the pair of ram bearings 5, one ram bearing 5 arranged closer to the die 8 is the front bearing 5F, and the other ram bearing 5 arranged closer to the reciprocating linear motion mechanism 10 is the rear bearing 5R. The front bearing 5F and the rear bearing 5R have a fluid bearing structure, such as a hydrostatic bearing or hydrostatic bearing.

A plurality of dies 8 are provided in line in the axial direction of the central axis O. Each of the plurality of dies 8 has a through hole 7 having a circular cross section penetrating the die 8 in the axial direction of the central axis O. The plurality of dies 8 includes one redrawing die 8A and a plurality of ironing dies (ironing dies) 8B located closer to the domer 11 than the redrawing die 8A. Although not shown in particular, a pilot ring is disposed on the domer 11 side of each ironing die 8B. The provision of the pilot ring prevents the punch 2 from contacting each ironing die 8B due to the impact when the DI can 100 leaves (passes through) each ironing die 8B during molding.
During forming, a coolant liquid is supplied to the redrawing die 8A and each ironing die 8B for lubrication and cooling.

The cup holder 6 has a cylindrical cup holder sleeve 6a extending in the axial direction of the central axis O. The cup holder sleeve 6a is fitted onto the outside of the punch 2 and is slidable in the axial direction of the central axis O relative to the punch 2. The cup holder sleeve 6a is inserted into the inside of a cup-shaped body W arranged on an end face 9 of the redrawing die 8A and holds the bottom wall of the cup-shaped body W by pressing it against the end face 9. In other words, the cup holder 6 supports the cup-shaped body W by pressing the bottom wall of the cup-shaped body W against the end face 9 facing the reciprocating linear motion mechanism 10 of the die 8.
Although not specifically shown, the cup holder drive mechanism converts the rotational drive force transmitted from the drive source via the reciprocating linear motion mechanism 10 into reciprocating motion in the axial direction of the central axis O, thereby moving the cup holder 6 back and forth in a linear manner in the axial direction of the central axis O.

The domer 11 is a die that forms the bottom of the DI can 100. The domer 11 is substantially cylindrical and extends in the axial direction of the central axis O. When the punch 2 is positioned at the forward end position in the stroke direction S, the domer 11 faces the punch 2 in the axial direction of the central axis O.

The DI processing into the cup-shaped body W by the can forming apparatus 1 is performed as follows.
First, the cup-shaped body W, which is the workpiece, is placed between the punch 2 and the redrawing die 8A with the cup axis (can axis) extended horizontally and its opening facing the punch 2. The bottom wall of the cup-shaped body W faces the end surface 9 of the redrawing die 8A.

The cup holder 6 and punch 2 are moved forward in the axial direction of the central axis O relative to this cup-shaped body W. That is, the cup holder 6 and punch 2 move in the stroke direction S from the reciprocating linear motion mechanism 10 toward the die 8, i.e., toward the front. Then, while the cup holder 6 presses the bottom wall of the cup-shaped body W against the end face 9 of the redrawing die 8A to perform a cup pressing operation, the punch 2 pushes the cup-shaped body W into the through hole 7 of the redrawing die 8A, thereby subjecting the cup-shaped body W to the redrawing process.

The redrawing process reduces the diameter of the cup-shaped body W and increases its length in the axial direction of the cup. The cup-shaped body W is then pressed into the punch 2 and ironed as it passes through each of the through holes 7 of the ironing dies 8B in sequence. That is, the peripheral wall of the cup-shaped body W is ironed and stretched, increasing the peripheral wall height and reducing the peripheral wall thickness, and is formed into the shape of a cylindrical DI can 100 with a bottom. The DI can 100 is cold-work hardened by ironing the peripheral wall, increasing its strength.

The ironed DI can 100 is pushed out by the punch 2 from the through hole 7 of the die 8 toward the domer 11. The bottom of the DI can 100 (the part that will become the bottom of the can) is then sandwiched and pressed between the punch 2 and the domer 11, so that the bottom of the DI can 100 is formed into a dome shape.

Next, the reciprocating linear motion mechanism 10 will be described.
As shown in Figures 2 and 3, the reciprocating linear motion mechanism 10 includes a housing 15 having an internal gear 16, a first rotating body 21, a first bearing 31, a recess 28, a second rotating body 22 having an external gear 23 that meshes with the internal gear 16, a convex portion 29, a second bearing 32, a ram shaft connecting portion 35, a weight portion 51, and a shaft body 26.

The housing 15 and its internal gear 16, the first rotor 21, the first bearing 31 and the shaft 26 are centered on the first central axis C1, i.e., are arranged coaxially with each other about the first central axis C1 as a common axis. The recess 28, the second rotor 22 and its external gear 23, the protrusion 29 and the second bearing 32 are centered on the second central axis C2, i.e., are arranged coaxially with each other about the second central axis C2 as a common axis.
The first central axis C1 and the second central axis C2 are parallel to each other and spaced apart from each other. In this embodiment, the first central axis C1 and the second central axis C2 extend in the horizontal direction.

In the following description, the direction in which the first central axis C1 extends and the direction in which the second central axis C2 extends are simply referred to as the axial direction. In the axial direction, the first rotating body 21 and the ram shaft connecting portion 35 are disposed at different positions from each other. In the axial direction, the direction from the first rotating body 21 to the ram shaft connecting portion 35 is referred to as one axial side, and the direction from the ram shaft connecting portion 35 to the first rotating body 21 is referred to as the other axial side. Note that the one axial side may also be referred to as the front side, and the other axial side may also be referred to as the rear side.

A direction perpendicular to the first central axis C1 is referred to as a first radial direction. In the first radial direction, a direction approaching the first central axis C1 is referred to as an inner side of the first radial direction, and a direction away from the first central axis C1 is referred to as an outer side of the first radial direction.
The direction of rotation around the first central axis C1 is referred to as a first circumferential direction. Within the first circumferential direction, the direction in which the first rotor 21 is rotated relative to the housing 15 during operation of the can forming apparatus 1 is referred to as a first rotational direction T1.

A direction perpendicular to the second central axis C2 is referred to as a second radial direction. In the second radial direction, a direction approaching the second central axis C2 is referred to as an inner side of the second radial direction, and a direction away from the second central axis C2 is referred to as an outer side of the second radial direction.
The direction of rotation around the second central axis C2 is referred to as a second circumferential direction. Of the second circumferential directions, the direction in which the second rotor 22 is rotated relative to the first rotor 21 during operation of the can forming apparatus 1 is referred to as a second rotation direction T2.

The housing 15 is cylindrical and centered on the first central axis C1. The housing 15 has an internal gear 16 and a housing body 17.

The internal gear 16 is annular and centered on the first central axis C1. The internal gear 16 is cylindrical and extends in the axial direction. The internal gear 16 is disposed at one end of the housing 15 in the axial direction. The internal gear 16 is located in an opening on one axial side of the housing 15.

The internal gear 16 has multiple internal teeth 16a arranged in a first circumferential direction on the inner periphery of the internal gear 16. In this embodiment, the internal teeth 16a are exposed to the outside of the reciprocating linear motion mechanism 10 through an opening on one axial side of the housing 15.

As shown in FIG. 3, the housing body 17 is a cylindrical shape with a bottom and centered on the first central axis C1. A first rotating body 21 and a first bearing 31 are arranged inside the housing body 17. An internal gear 16 is fixed to one axial end of the housing body 17.

The housing body 17 has a peripheral wall portion 17a and a bottom wall portion 17b.
The peripheral wall portion 17a is generally cylindrical and centered on the first central axis C1, and extends in the axial direction. The internal gear 16 is fixed to one axial end of the peripheral wall portion 17a. The bottom wall portion 17b is connected to the other axial end of the peripheral wall portion 17a.
The bottom wall portion 17b is annular and extends in a direction perpendicular to the first central axis C1. The outer periphery of the bottom wall portion 17b is connected to the other axial end of the peripheral wall portion 17a. In the illustrated example, the peripheral wall portion 17a and the bottom wall portion 17b are integrally formed.

The first rotating body 21 is located inside the housing 15 in the first radial direction. The first rotating body 21 is connected to the housing 15 so as to be capable of relative rotation around the first central axis C1. The first rotating body 21 is cylindrical and centered on the first central axis C1. The first rotating body 21 is accommodated within the housing 15.

The first bearing 31 is, for example, a tapered roller bearing. The first bearing 31 is capable of supporting a load from a first radial direction (radial load) and a load from an axial direction (axial load). The first bearing 31 is annular about a first central axis C1. The first bearing 31 connects the housing 15 and the first rotating body 21 to be capable of relative rotation about the first central axis C1.
Although not particularly shown, an outer ring of the first bearing 31 is fixed to an inner circumferential surface of the peripheral wall portion 17a of the housing body 17. An inner ring of the first bearing 31 is fixed to an outer circumferential surface of the first rotating body 21.

The recess 28 is recessed from the surface 21d facing one axial side of the first rotor 21 toward the other axial side and extends in the axial direction. The recess 28 is a circular hole centered on the second central axis C2. In other words, the recess 28 opens to one axial side.

The second rotating body 22 is disposed on one axial side of the first rotating body 21. The second rotating body 22 is connected to the first rotating body 21 so as to be capable of relative rotation about the second central axis C2. The second rotating body 22 is substantially cylindrical and centered on the second central axis C2. The second rotating body 22 has an external gear 23 and a top wall portion 22b.

The external gear 23 is cylindrical and centered on the second central axis C2, and extends in the axial direction. A part of the surface 22e of the external gear 23 facing the other axial side faces a part of the surface 21d of the first rotor 21 facing one axial side with a gap in the axial direction. Another part of the surface 22e of the external gear 23 facing the other axial side faces a part of the first bearing 31 with a gap in the axial direction. In other words, when viewed from the axial direction, a part of the external gear 23 and a part of the first bearing 31 overlap each other. The external gear 23 is located at an opening on one axial side of the housing 15.

The external gear 23 has a plurality of external teeth 23a arranged in the second circumferential direction on the outer periphery of the external gear 23. In this embodiment, the external teeth 23a are exposed to the outside of the reciprocating linear motion mechanism 10 through an opening on one axial side of the housing 15.
At least one of the plurality of external teeth 23a meshes with at least one of the plurality of internal teeth 16a. The pitch circle diameter of the external teeth 23a of the external gear 23 is half the pitch circle diameter of the internal teeth 16a of the internal gear 16.

2, when the can forming apparatus 1 is in operation, the external gear 23 rotates (revolves) in a first rotational direction T1 along the inner periphery of the internal gear 16 while rotating (rotating) in a second rotational direction T2. In this embodiment, when the reciprocating linear motion mechanism 10 is viewed from one axial side, that is, when viewed from the front of the reciprocating linear motion mechanism 10, the first rotational direction T1 is a counterclockwise direction centered on the first central axis C1, and the second rotational direction T2 is a clockwise direction centered on the second central axis C2. However, this is not limited to this, and when the reciprocating linear motion mechanism 10 is viewed from one axial side, the first rotational direction T1 may be a clockwise direction centered on the first central axis C1, and the second rotational direction T2 may be a counterclockwise direction centered on the second central axis C2.

The top wall portion 22b is disposed on one axial side of the external gear 23. The top wall portion 22b is disk-shaped and extends in a direction perpendicular to the second central axis C2. As shown in FIG. 3, the top wall portion 22b is connected to one axial end of the external gear 23 and the other axial end of the ram shaft connecting portion 35. In other words, the top wall portion 22b connects the external gear 23 and the ram shaft connecting portion 35.

The protrusion 29 protrudes from the surface 22e facing the other axial side of the second rotating body 22 in the axial direction and extends in the axial direction. The protrusion 29 is cylindrical and centered on the second central axis C2. The protrusion 29 is inserted into the recess 28.

The second bearing 32 is, for example, a tapered roller bearing. The second bearing 32 can support a load from a second radial direction (radial load) and a load from an axial direction (axial load). The second bearing 32 is annular about a second central axis C2. The second bearing 32 connects the protrusion 29 and the recess 28 to be relatively rotatable about the second central axis C2.
Although not particularly shown, an outer ring of the second bearing 32 is fixed to an inner circumferential surface of the recessed portion 28. An inner ring of the second bearing 32 is fixed to an outer circumferential surface of the protruding portion 29.

When viewed from the second radial direction, the first bearing 31, the recess 28, the second bearing 32, and the protrusion 29 overlap one another. That is, the first bearing 31, the recess 28, the second bearing 32, and the protrusion 29 each include a portion that is arranged at the same position as one another in the axial direction. In the illustrated example, when viewed from the second radial direction, the second bearing 32 overlaps with the first bearing 31 over its entire axial length.
The internal gear 16 and the external gear 23 are disposed on one axial side of the first bearing 31 , the recessed portion 28 , the second bearing 32 and the protruding portion 29 .

The ram shaft connecting portion 35 is connected to the second rotor 22 and is caused to move back and forth linearly along a predetermined direction (stroke direction S) in the first radial direction. The ram shaft connecting portion 35 is, for example, cylindrical and extends in the axial direction. The ram shaft connecting portion 35 protrudes from the top wall portion 22b to one side in the axial direction. The ram shaft connecting portion 35 is located on one side in the axial direction relative to the housing 15. The ram shaft connecting portion 35 protrudes from the top wall portion 22b to the outside in the second radial direction.

The third central axis C3 of the ram shaft connecting part 35 is parallel to the first central axis C1. The third central axis C3 of the ram shaft connecting part 35 is arranged parallel to and spaced apart from the second central axis C2. The second radial distance between the third central axis C3 and the second central axis C2 is equal to the second radial distance between the first central axis C1 and the second central axis C2. When the reciprocating linear motion mechanism 10 is viewed from the axial direction, the third central axis C3 of the ram shaft connecting part 35 is located on the pitch circle diameter of the external teeth 23a of the external gear 23.

In FIG. 1, the ram shaft connecting portion 35 is connected to the ram shaft 3 via a connecting bearing (not shown) that is provided on the outer periphery of the ram shaft connecting portion 35. This connecting bearing connects the ram shaft connecting portion 35 to a connecting rod located at one end of the ram shaft 3 so that they can rotate relatively around the third central axis C3.

2 and 3, the weight portion 51 is connected to the first rotor 21 and is located on the opposite side of the second center axis C2 in the first radial direction, sandwiching the first center axis C1 therebetween. The weight portion 51 functions as a so-called counterweight for maintaining good rotational balance in the first circumferential direction when the first rotor 21, the recessed portion 28, the protruding portion 29, the second bearing 32, the second rotor 22, and the ram shaft connecting portion 35 rotate around the first center axis C1. The weight portion 51 is located on one axial side of the first rotor 21. The weight portion 51 is semicircular. In the illustrated example, the weight portion 51 is formed integrally with the first rotor 21.

The shaft body 26 is cylindrical and centered on the first central axis C1, and extends in the axial direction. The shaft body 26 is disposed on the other axial side of the first rotating body 21. The outer diameter of the shaft body 26 is smaller than the outer diameter of the first rotating body 21. The end of the shaft body 26 on one axial side is connected to the end of the first rotating body 21 on the other axial side. In the illustrated example, the shaft body 26 is formed integrally with the first rotating body 21.

The shaft body 26 is supported by a third bearing (not shown) so as to be rotatable about the first central axis C1. A rotational driving force in a first rotational direction T1 is input to the shaft body 26 from a driving source (not shown). The shaft body 26 and the first rotating body 21 are rotated in the first rotational direction T1 relative to the housing 15 by the rotational driving force of the driving source.

In the reciprocating linear motion mechanism 10 of this embodiment described above, when a rotational driving force about the first central axis C1 is transmitted from a driving source (not shown) to the shaft body 26 and the first rotating body 21, the first rotating body 21 is rotated about the first central axis C1 relative to the housing 15. When the first rotating body 21 is rotated about the first central axis C1, the second rotating body 22 supported by the first rotating body 21 is also rotated about the first central axis C1.

At this time, because the external gear 23 of the second rotating body 22 and the internal gear 16 of the housing 15 are meshed with each other, the second rotating body 22 is rotated (revolved) around the first central axis C1 while also rotating (rotating) around the second central axis C2. When the reciprocating linear motion mechanism 10 is viewed from the axial direction, the first rotation direction T1 in which the second rotating body 22 is revolved around the first central axis C1 and the second rotation direction T2 in which the second rotating body 22 is rotated around the second central axis C2 are opposite to each other.

The ram shaft connecting portion 35 connected to the second rotor 22 performs linear reciprocating motion along a predetermined direction in the first radial direction, that is, along the stroke direction S.
In this way, the reciprocating linear motion mechanism 10 of the present embodiment converts the rotational driving force input to the first rotor 21 into reciprocating linear motion in the stroke direction S and outputs it to the ram shaft connecting part 35. As a result, the punch 2 connected to the ram shaft connecting part 35 via the ram shaft 3 is caused to perform reciprocating linear motion in the stroke direction S. The punch 2, die 8, cup holder 6, etc. make it possible to perform DI processing on the cup-shaped body W, and the cup-shaped body W can be formed into a DI can 100.

And according to this embodiment, the first bearing 31, the recess 28, the second bearing 32, and the protrusion 29 are arranged to overlap each other when viewed from the second radial direction. That is, the axial positions of the first bearing 31, the recess 28, the second bearing 32, and the protrusion 29 are the same, so the bulkiness of the axial dimension of the reciprocating linear motion mechanism 10 can be suppressed. It is also easy to keep the axial dimensions of the external gear 23 and the internal gear 16 small. At least the axial outer shape of the reciprocating linear motion mechanism 10 can be kept small, and the structure can be simplified.

In this embodiment, the internal gear 16 and the external gear 23 are disposed on one axial side of the first bearing 31 , the recessed portion 28 , the second bearing 32 and the protruding portion 29 .
In this case, the structure of the reciprocating linear motion mechanism 10 can be simplified while the outer dimensions in the axial direction can be made smaller.

In this embodiment, the internal gear 16 and the external gear 23 are located at an opening on one axial side of the housing 15 .
In this case, the structure of the reciprocating linear motion mechanism 10 can be simplified while the outer dimensions in the axial direction can be made smaller.

In this embodiment, a portion of the external gear 23 and a portion of the first bearing 31 overlap each other when viewed in the axial direction.
For example, unlike the present embodiment, in which the first bearing 31 does not overlap with the external gear 23 when viewed from the axial direction and is positioned further outward in the first radial direction than the external gear 23, the above-described configuration of the present embodiment allows the diameter of the first bearing 31 to be kept small, thereby enabling the outer shape of the reciprocating linear motion mechanism 10 in the first radial direction to be kept small.

In this embodiment, the second bearing 32 is arranged to overlap the first bearing 31 over its entire axial length when viewed from the second radial direction.
In this case, a large axial dimension of the second bearing 32 is ensured, so that the load acting on the second bearing 32 from the second radial direction is easily distributed, and the load is prevented from varying greatly at each axial position of the second bearing 32. Since the load on the second bearing 32 is equalized in the axial direction, the function of the second bearing 32 is well maintained, and the frequency of maintenance and the like can be reduced.

The present invention is not limited to the above-described embodiment, and the configuration may be modified without departing from the spirit of the present invention, for example as described below.

The shape of the weight portion 51 is not limited to the shape described in the above embodiment.
Although not shown, a second weight portion connected to the top wall portion 22b of the second rotor 22 may be provided in addition to the weight portion (first weight portion) 51. In this case, the second weight portion is located on the opposite side to the ram shaft connecting portion 35 in the second radial direction, with the second central axis C2 in between. The second weight portion functions as a so-called counterweight for maintaining good rotational balance in the second circumferential direction when the second rotor 22, the protrusion 29, and the ram shaft connecting portion 35 rotate around the second central axis C2.

The present invention may be implemented by combining the various configurations described in the above-mentioned embodiments and modifications, etc., without departing from the spirit of the present invention, and addition, omission, substitution, and other modifications of configurations are possible. Furthermore, the present invention is not limited to the above-mentioned embodiments, etc., but is limited only by the scope of the claims.

The reciprocating linear motion mechanism of the can forming device and the can forming device of the present invention can keep the external dimensions of the reciprocating linear motion mechanism small. Therefore, it has industrial applicability.

1...can forming device, 2...punch, 3...ram shaft, 6...cup holder, 7...through hole, 8...die, 9...end face, 10...reciprocating linear motion mechanism, 15...housing, 16...internal gear, 21...first rotor, 21d...surface facing one axial side of the first rotor, 22...second rotor, 22e...surface facing the other axial side of the second rotor, 23...external gear, 28...recess, 29...projection, 31...first bearing, 32...second bearing, 35...ram shaft connection, C1...first central shaft, C2...second central shaft

Claims (5)

a housing having an internal gear centered on a first central axis;
a first rotor located inside the housing in a first radial direction perpendicular to the first central axis;
a first bearing that connects the housing and the first rotor to be capable of relative rotation about the first central axis;
a recessed portion recessed from a surface of the first rotor facing one axial direction toward the other axial direction and centered on a second central axis parallel to the first central axis;
a second rotor having an external gear meshing with the internal gear and centered on the second central axis, the second rotor being disposed on one axial side of the first rotor;
a protrusion that protrudes from a surface of the second rotor facing the other axial direction toward the other axial direction and is inserted into the recess;
a second bearing that connects the protruding portion and the recessed portion so as to be relatively rotatable about the second central axis;
a ram shaft connecting portion connected to the second rotor and capable of reciprocating linear motion along a predetermined direction in the first radial direction;
The internal gear is disposed at one axial end of the housing,
The first rotating body is accommodated in the housing,
When viewed from a second radial direction perpendicular to the second central axis, the first bearing, the recessed portion, the second bearing, and the protruding portion overlap each other.
Reciprocating linear motion mechanism for can forming equipment. the internal gear and the external gear are disposed on one axial side of the first bearing, the recess, the second bearing, and the protrusion.
2. The reciprocating linear motion mechanism of a can forming apparatus according to claim 1. The internal gear and the external gear are located in an opening on one axial side of the housing.
3. The reciprocating linear motion mechanism for a can forming apparatus according to claim 1 or 2. The first bearing and the second bearing are not on one axial side of the internal gear and the external gear.
The reciprocating linear motion mechanism for a can forming apparatus according to any one of claims 1 to 3. A reciprocating linear motion mechanism for a can forming apparatus according to any one of claims 1 to 4;
a ram shaft extending in the predetermined direction and having one end connected to the ram shaft connecting portion;
a punch disposed at the other end of the ram shaft;
a die having a through hole into which the punch is inserted;
a cup holder that is pressed against an end surface of the die where the through hole is open.
Can forming equipment.

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