SWAGING DEVICE AND SWAGING METHOD

INCORPORATION BY REFERENCE

This application is based upon and claims the benefit of priority from Japanese patent application No. 2014-96760, filed on May 8, 2014, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a swaging device and a swaging method. For example, the present invention relates to a swaging device and a swaging method in which an end of a tubular body fixed on a rotatable table and a circumferential edge of an end plate for closing an opening of the tubular body are swaged together.

2. Description of Related Art

For example, a muffler of an automobile has usually a structure in which a pressed article is attached to a main pipe by a swaging process. In such a swaging process, swaging is performed by pushing a roller into an end of a main pipe and a circumferential edge of a pressed article by a conforming method (or copying method) by using a model form (or die).

In a swaging device disclosed in Japanese Unexamined Patent Application Publication No, 2001-300666, swaging is performed by placing a flange of a tubular body formed by raising an end of the tubular body outward and a circumferential edge of an end plate for closing an opening of the tubular body on top of one another, holding the tubular body and the end plate by a core metal disposed inside the tubular body and receiving means disposed outside the end plate, pushing a roller onto the core metal, sandwiching the flange of the tubular body and the circumferential edge of the end plate by the roller and the core metal, and conforming the roller to a rotation of the tubular body.

The present inventors have found the following problem. A typical swaging device has a configuration in which a model form is disposed inside a tubular body, and a roller is pushed so that the model form and the roller sandwich the flange of the tubular body and the circumferential edge of the end plate therebetween. In this process, since a reactive force to the force for pushing the flange of the tubular body and the circumferential edge of the end plate exerted by the roller is transferred to the mechanism for controlling the position of the roller, this mechanism needs to have a structure strong enough to tolerate the reactive force, thus increasing the cost for the swaging device.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a swaging device and a swaging method capable of simplifying the mechanism for controlling the position of the roller(s) and contributing to a reduction in the cost thereof.

A first exemplary aspect of the present invention is a swaging device that swages an end of a tubular body and a circumferential edge of an end plate for closing an opening of the tubular body by utilizing a processing roller, in which

the processing roller is connected to a robot, the robot being configured to control a position of the processing roller, and swaging is performed by sandwiching the end of the tubular body and the circumferential edge of the end plate by an inner roller and an outer roller, the inner roller being disposed inside the tubular body, the outer roller being disposed outside the tubular body so that the outer roller is opposed to the inner roller, and the outer roller being movable toward the inner roller.

In the above-described swaging device, the force for pushing the end of the tubular body and the circumferential edge of the end plate exerted by the outer roller is roughly equal to the force acting to push back the outer roller exerted by the inner roller, and their reactive forces act on the robot so that they cancel out each other. As a result, the reactive force is not substantially transferred to the robot. Therefore, there is no need to construct the robot with a strong structure, thus making it possible to simplify the robot and to contribute to a reduction in the cost thereof.

In the above-described swaging device, the robot preferably controls positions of the inner and outer rollers so that rotation axes of the inner and outer rollers are in parallel with a surface sandwiched by the inner and outer rollers in the tubular body, and a direction in which the outer roller moves toward the inner roller is disposed on a normal of the sandwiched surface.

This makes it possible to reliably transfer a force acting for moving the outer roller toward the inner roller to the end of the tubular body and the circumferential edge of the end plate.

The above-described swaging device preferably further includes a first grasping part and a second grasping part for sandwiching and fixing the tubular body, and

the first and second grasping parts can preferably be replaced according to a shape of the tubular body to be fixed.

As a result, the first and second grasping parts can be replaced according to the shape of the tubular body, thus increasing the general-purpose property of the swaging device.

In the above-described swaging device, the outer roller preferably includes a first roller and a second roller, and

a straight line extending in a direction in which the first roller moves toward the inner roller and a straight line extending in a direction in which the second roller moves toward the inner roller preferably intersect with each other.

As a result, the first and second rollers can be easily chosen, thus improving the productivity.

In the above-described swaging device, the robot preferably controls the positions of the inner and outer rollers so that their positions conform to the end of the tubular body and the circumferential edge of the end plate.

This makes it possible to omit the conforming mechanism (or copying mechanism) of conventional swaging devices, thus simplifying the swaging device.

The above-described swaging device preferably further includes a pressure adjustment unit that adjusts the force for pushing the end of the tubular body and the circumferential edge of the end plate in the outer roller to a value equal to or lower than a predetermined threshold.

This makes it possible to make the outer roller push the end of the tubular body and the circumferential edge of the end plate with an appropriate pressure.

The above-described swaging device preferably further includes a rotatable table that rotates the tubular body, and

the robot and the rotatable table preferably operate in cooperation with each other.

This makes it possible to narrow the operating range of the robot, thus contributing to a reduction in the size of the robot.

Another exemplary aspect of the present invention is a swaging method for swaging an end of a tubular body and a circumferential edge of an end plate for closing an opening of the tubular body by utilizing a processing roller, the swaging method including:

controlling positions of an inner roller and an outer roller, the inner and outer rollers being the processing roller, the processing roller being connected to a robot;

disposing the inner roller inside the tubular body;

disposing the outer roller outside the tubular body so that the outer roller is opposed to the inner roller; and

moving the outer roller toward the inner roller, sandwiching the end of the tubular body and the circumferential edge of the end plate by the outer and inner rollers, and thereby swaging the end of the tubular body and the circumferential edge of the end plate together.

In the above-described swaging method, a force for pushing the end of the tubular body and the circumferential edge of the end plate exerted by the outer roller is roughly equal to a force acting to push back the outer roller exerted by the inner roller, and their reactive forces act on the robot so that they cancel out each other. As a result, the reactive force is not substantially transferred to the robot. Therefore, there is no need to construct the robot with a strong structure, thus making it possible to simplify the robot and to contribute to a reduction in the cost thereof.

In the above-described swaging method, the robot preferably controls positions of the inner and outer rollers so that rotation axes of the inner and outer rollers are in parallel with a surface sandwiched by the inner and outer rollers in the tubular body, and a direction in which the outer roller moves toward the inner roller is perpendicular to the sandwiched surface.

This makes it possible to reliably transfer a force acting for moving the outer roller toward the inner roller to the end of the tubular body and the circumferential edge of the end plate.

In the above-described swaging method, the robot preferably controls the positions of the inner and outer rollers so that their positions conform to the end of the tubular body and the circumferential edge of the end plate.

This makes it possible to omit the conforming mechanism (or copying mechanism) of conventional swaging devices, thus simplifying the swaging device.

According to the present invention, it is possible to provide a swaging device and a swaging method capable of simplifying the mechanism for controlling the position of the roller(s) and contributing to a reduction in the cost thereof.

The above and other objects, features and advantages of the present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a swaging device according to a first exemplary embodiment;

FIG. 2 is an enlarged front view showing a swaging section of the swaging device according to the first exemplary embodiment;

FIG. 3 is a plan view showing a state where an end of a tubular body and a circumferential edge of an end plate are sandwiched by an inner roller and an outer roller;

FIG. 4 is a block diagram of a control system of the swaging device according to the first exemplary embodiment;

FIG. 5 is a plan view showing a fixing jig provided in a rotatable table;

FIG. 6 is a front view showing the fixing jig;

FIG. 7 shows a positional relation among the tubular body, and the inner and outer rollers when the tubular body is rotated;

FIG. 8 shows another tubular body that can be swaged by the swaging device according to the first exemplary embodiment;

FIG. 9 shows another tubular body that can be swaged by the swaging device according to the first exemplary embodiment;

FIG. 10 is a plan view showing a swaging section according to a second exemplary embodiment;

FIG. 11 is a plan view showing the swaging section according to the second exemplary embodiment; and

FIGS. 12(
a) to 12(e) schematically show a flow of a swaging process according to the second exemplary embodiment.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Specific exemplary embodiments to which the present invention is applied are explained hereinafter with reference to the drawings. However, the present invention is not limited to the below-shown exemplary embodiments. Further, the following descriptions and the drawings may be partly omitted and simplified as appropriate for clarifying the explanations.

First Exemplary Embodiment

Firstly, an outline of a swaging device and a swaging method according to this exemplary embodiment is explained. FIG. 1 is a front view showing a swaging device according to this exemplary embodiment. FIG. 2 is an enlarged front view showing a swaging section of the swaging device according to this exemplary embodiment. FIG. 3 is a plan view showing a state where an end of a tubular body and a circumferential edge of an end plate are sandwiched by an inner roller and an outer roller.

A swaging device 1 according to this exemplary embodiment is used, for example, to manufacture a muffler of an automobile. As shown in FIGS. 1 and 2, the swaging device 1 swages an end of a tubular body 2 and a circumferential edge of an end plate 3 for closing an opening 2a of the tubular body 2 by utilizing processing rollers 4.

Note that the processing rollers 4 are connected to a robot 5 that controls the positions of the processing rollers 4. The processing rollers 4 includes an inner roller 6 disposed inside the tubular body 2 and an outer roller 7 disposed outside the tubular body 2 so that the outer roller 7 is opposed to the inner roller 6. The outer roller 7 can be moved toward the inner roller 6. The swaging device 1 sandwiches the end of the tubular body 2 and the circumferential edge of the end plate 3 by the inner and outer rollers 6 and 7 and thereby swages them together.

That is, the swaging device and the swaging method according to this exemplary embodiment control the robot 5, dispose the inner roller 6 inside the tubular body 2, dispose the outer roller 7 outside the tubular body 2 so that the outer roller 7 is opposed to the inner roller 6, sandwich the end of the tubular body 2 and the circumferential edge of the end plate 3 by the inner and outer rollers 6 and 7 by moving the outer roller 7 toward the inner roller 6, and thereby swage them together.

In the above-described swaging device 1 and the swaging method, the force for pushing the end of the tubular body 2 and the circumferential edge of the end plate 3 exerted by the outer roller 7 is roughly equal to the force acting to push back the outer roller 7 exerted by the inner roller 6, and their reactive forces act on the robot 5 so that they cancel out each other. As a result, the reactive force is not substantially transferred to the robot 5. Therefore, there is no need to construct the robot 5 with a strong structure, thus making it possible to simplify the robot 5 and to contribute to a reduction in the cost thereof.

Next, a swaging device according to this exemplary embodiment is explained in detail. FIG. 4 is a block diagram of a control system of the swaging device according to this exemplary embodiment. FIG. 5 is a plan view showing a fixing jig provided in a rotatable table. FIG. 6 is a front view showing the fixing jig.

A tubular body 2 and an end plate 3 used in this exemplary embodiment are explained hereinafter. Note that the following explanations of the tubular body 2 and the end plate 3 are given with reference to the right side of FIG. 1.

The tubular body 2 is, for example, a main pipe of a rolled muffler of an automobile, and is formed by shaping a steel plate into a tubular shape. As shown in the right side of FIG. 1, the tubular body 2 according to this exemplary embodiment is a straight pipe having a rounded-corner rectangular shape in a cross section when cut on a plane perpendicular to the height direction of the tubular body 2. Further, as shown in FIG. 2, each opened end of the tubular body 2 is formed as a flange 2b that is formed by raising the end of the tubular body 2 outward. However, the cross-sectional shape of the tubular body 2 as cut on the plane perpendicular to the height direction of the tubular body 2 may be other shapes such as an ellipse and a circle. Further, the shape of the tubular body 2 as viewed in the thickness direction may be roughly a trapezoid.

The end plate 3 is, for example, a pressed article formed by pressing a steel plate. The end plate 3 according to this exemplary embodiment has a rounded-corner rectangular shape as viewed in the height direction of the end plate 3 so that it corresponds to the shape of the tubular body 2. Further, an area inside a circumferential edge 3a of the end plate 3 is formed as a planar section 3b that is recessed with reference to the circumferential edge 3a. Further, a rising section 3c is interposed between the circumferential edge 3a and the planar section 3b. Note that the shape of the end plate 3 may be defined as appropriate according to the shape of the opened end of the tubular body 2.

As shown in FIG. 2, when the planar section 3b of the end plate 3 is inserted in the opening 2a of the tubular body 2, the circumferential edge 3a of the end plate 3 is placed over the flange 2b of the tubular body 2 so that the surfaces of this edge and flange are roughly in contact with each other. Further, the surface of the rising part 3c of the end plate 3 is roughly brought into contact with the inner circumferential surface of the tubular body 2. Note that various parameters such as the angle at which the flange 2b of the tubular body 2 is raised outward, the size of the flange 2b, the depth of the planar section 3b of the end plate 3, and the inclination angle of the rising part 3c may be defined as appropriate.

The swaging device 1 includes a rotatable table 8, a swaging section 9, a robot 5, and a control unit 10. As shown in FIG. 1, the rotatable table 8 includes a fixing jig 11 and a main body 12.

As shown in FIGS. 5 and 6, the fixing jig 11 includes a first fixing part 11a, a second fixing part 11b, a first drive mechanism 11c, a second drive mechanism 11d, and a housing 11e. Note that the following explanation of the fixing jig 11 is given with reference to the fixing jig 11 shown in FIGS. 5 and 6.

The first and second fixing parts 11a and 11b sandwich and fix the tubular body 2 therebetween. In this exemplary embodiment, the tubular body 2 is inserted between the first and second fixing parts 11a and 11b from above the fixing jig 11. Further, the first and second fixing parts 11a and 11b sandwich and fix the tubular body 2 in the thickness direction of the tubular body 2.

The first fixing part 11a includes a grasping part 11f and a frame part 11g. The grasping part 11f includes a recessed part 11h that corresponds to one of the shapes obtained by dividing the tubular body 2 into two sections in the thickness direction. The grasping part 11f is removably attached to the frame part 11g by using, for example, an engaging structure. However, the only requirement is that the grasping part 11f should be removably attached to the frame part 11g. That is, the grasping part 11f may be attached to the frame part 11g by fixing means other than the engaging structure, such as a bolt. The left and right ends of the frame part 11g are connected to the first and second drive mechanisms 11c and 11d, respectively.

The second fixing part 11b has a structure roughly identical to that of the first fixing part 11a, and includes a grasping part 11i and a frame part 11j. The grasping part 11i includes a recessed part 11k that corresponds to the other of the shapes obtained by dividing the tubular body 2 into two sections in the thickness direction. The recessed part 11k is opposed to the recessed part 11h of the first fixing part 11a in the front/back direction of the fixing jig 11. That is, when the first fixing part 11a is brought into contact with the second fixing part 11b in the front/back direction of the fixing jig 11, the shape formed by the recessed parts 11h and 11k of the first and second fixing part 11a and 11b, respectively, corresponds to the external shape of the tubular body 2.

The grasping part 11i is removably attached to the frame part 11j by using, for example, an engaging structure. However, the only requirement is that the grasping part 11i should be removably attached to the frame part 11j. That is, the grasping part 11i may be attached to the frame part 11j by fixing means other than the engaging structure, such as a bolt. The left and right ends of the frame part 11j are connected to the first and second drive mechanisms 11c and 11d, respectively.

The first drive mechanism 11c moves the left end of the fixing jig 11 in each of the first and second fixing parts 11a and 11b in the front/back direction of the fixing jig 11. The first drive mechanism 11c according to this exemplary embodiment is disposed so that the recessed parts 11h and 11k of the respective first and second fixing part 11a and 11b are interposed between the first and second drive mechanisms 11c and 11d in the left/right direction of the fixing jig 11. Further, the first drive mechanism 11c includes rail members 11l and a rod screw 11m.

The rail members 11l are disposed roughly in parallel with the rod screw 11m and extend in the front/back direction of the fixing jig 11. Further, the rail members 11l are arranged in the vertical direction (or, up/down direction) of the fixing jig 11 with intervals therebetween, and each rail member 11l is supported by the housing 11e. Further, the rail members 11l are engaged with recesses formed in the left end of the fixing jig 11 in each of the frame parts 11g and 11j.

The rod screw 11m is rotatably supported in the housing 11e. Further, the rod screw 11m is screwed into a threaded hole that is formed at the left end of the fixing jig 11 and penetrates the fixing jig 11 in the front/back direction of the fixing jig 11 in each of the frame parts 11g and 11j.

The second drive mechanism 11d moves the right end of the fixing jig 11 in each of the first and second fixing parts 11a and 11b in the front/back direction of the fixing jig 11. The second drive mechanism 11d according to this exemplary embodiment includes rail members 11n and a rod screw 11o.

The rail members 11n are disposed roughly in parallel with the rod screw 11o and extend in the front/back direction of the fixing jig 11. Further, the rail members 11n are arranged in the vertical direction of the fixing jig 11 with intervals therebetween, and both ends of each rail member 11n are supported by the housing 11e. Further, the rail members 11n are engaged with recesses formed in the right end of the fixing jig 11 in each of the frame parts 11g and 11j.

The rod screw 11o is rotatably supported in the housing 11e. Further, the rod screw 11o is screwed into a threaded hole that is formed at the right end of the fixing jig 11 and penetrates the fixing jig 11 in the front/back direction of the fixing jig 11 in each of the frame parts 11g and 11j.

The housing 11e has a box shape with an opening formed on the top. The housing 11e contains the first and second fixing parts 11a and 11b, and the first and second drive mechanisms 11c and 11d.

In the above-described fixing jig 11, when the rod screws 11m and 11o are rotated in one direction, the first and second fixing parts 11a and 11b move so that they get closer to each other in the front/back direction of the fixing jig 11. Further, when the rod screws 11m and 11o are rotated in the other direction, the first and second fixing parts 11a and 11b move away from each other in the front/back direction of the fixing jig 11.

Therefore, it is possible to sandwich and fix the tubular body 2 by the recessed parts 11h and 11k of the first and second fixing part 11a and 11b in the thickness direction of the tubular body 2, and unfix and release the tubular body 2.

In addition, each of the grasping parts 11f and 11i can be attached and removed from the frame parts 11g and 11j, respectively, thus making it possible to replace the grasping parts 11f and 11i according to the shape of the tubular body 2 (i.e., the external shape of the tubular body 2) and thereby increase the general-purpose property of the swaging device 1.

Note that although the first and second fixing part 11a and 11b are moved by rotating the rod screws 11m and 11o in this exemplary embodiment, the first and second fixing part 11a and 11b may be moved by using an actuator(s) or the like in other embodiments. Further, the only requirement is that it should be possible for at least one of the first and second fixing part 11a and 11b to be moved.

As shown in FIG. 1, the main body 12 includes a placement section 12a, a support section 12b, and a drive mechanism 12c. Note that the following explanation of the main body 12 is given with reference to the main body 12 shown in FIG. 1.

The placement section 12a is disposed above the support section 12b. The support section 12b supports the placement section 12a in such a manner that the placement section 12a can rotate around an axis AX1 extending in the vertical direction of the main body 12. Further, the drive mechanism 12c is disposed on the support section 12b.

The drive mechanism 12c includes a motor, a speed reducer, and so on, and its output shaft extends in the vertical direction of the main body 12. This output shaft is connected to the lower surface of the placement section 12a. Further, the motor of the drive mechanism 12c operates based on a control signal supplied from the control unit 10.

On the above-described placement section 12a in the main body 12, the fixing jig 11 is placed and fixed so that an axis AX2 that passes through the center O1 (see FIG. 5) of the cross-sectional shape of the tubular body 2, which is fixed to the fixing jig 11, on a plane perpendicular to the height direction of the tubular body 2 and extends in the vertical direction of the fixing jig 11 roughly coincides with the rotation axis AX1 of the placement section 12a.

As shown in FIG. 2, the swaging section 9 includes processing rollers 4, a guide mechanism 13, a drive mechanism 14, a connection section 15, and a pushing mechanism 16. Note that the following explanation of the swaging section 9 is given with reference to the swaging section 9 shown in FIG. 2.

As described above, the processing rollers 4 include an inner roller 6 and an outer roller 7. The inner roller 6 has a cylindrical shape as a fundamental shape, and includes a circumferential surface 6a that comes into contact with the rising part 3c of the end plate 3. Further, the inner roller 6 is rotatably supported from above the inner roller 6 by the connection section 15 through a rotation shaft 6b in a cantilever fashion. This inner roller 6 can be removably attached to the rotation shaft 6b by using fixing means such as a nut.

The outer roller 7 has a cylindrical shape as a fundamental shape, and includes a circumferential surface 7a for pushing the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3. In roughly the center in the vertical direction of the swaging section 9 in this circumferential surface 7a, a recess 7c for rolling in the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 and thereby swaging them together is formed.

Further, the outer roller 7 is rotatably supported from above the outer roller 7 by the guide mechanism 13 through a rotation shaft 7b in a cantilever fashion. This outer roller 7 can be removably attached to the rotation shaft 7b by using fixing means such as a nut. With the above-described configuration, each of the inner and outer rollers 6 and 7 can be replaced as desired.

The circumferential surface 7a of the outer roller 7 is disposed so as to be opposed to the circumferential surface 6a of the inner roller 6 in the left/right direction of the swaging section 9. Further, the rotation shaft 7b of the outer roller 7 is disposed roughly in parallel with the rotation shaft 6b of the inner roller 6 as viewed in the front/back direction of the swaging section 9, and extends in the vertical direction of the swaging section 9. Further, as shown in FIG. 3, a straight line L1 that is perpendicular to the rotation shaft 6b of the inner roller 6 and connects the rotation shaft 7b of the outer roller 7 with the rotation shaft 6b of the inner roller 6 extends in the left/right direction of the swaging section 9.

The guide mechanism 13 guides the outer roller 7 in the left/right direction of the swaging section 9. The guide mechanism 13 according to this exemplary embodiment includes a rail member(s) 13a, a slider 13b, and a support member 13c. The rail member 13a extends in the left/right direction of the swaging section 9.

The slider 13b is engaged with the rail member 13a and fixed to the connection section 15. The support member 13c supports the rail member 13a, and the rotation shaft 7b of the outer roller 7 is connected to the left end of the support member 13c.

The drive mechanism 14 includes a cylinder 14a and a pressurization/decompression unit 14b. The cylinder 14a is fixed to the connection section 15 through a fixing jig 14c. A rod 14d of the cylinder 14a is connected to the support member 13c of the guide mechanism 13. Further, a central axis AX3 of the rod 14d is located on the straight line L1 as viewed in the vertical direction of the swaging section 9 and extends in the left/right direction of the swaging section 9.

The pressurization/decompression unit 14b operates based on a control signal supplied from the control unit 10, and extends/contracts the rod 14d of the cylinder 14a by pressurizing or decompressing the cylinder 14a by using a fluid or a gas.

The connection section 15 supports the inner roller 6, the guide mechanism 13 supporting the roller 7, and the drive mechanism 14. Further, the connection section 15 is connected to the robot 5. The pushing mechanism 16 pushes the planar section 3b of the end plate 3. The pushing mechanism 16 according to this exemplary embodiment includes a ball plunger and is fixed to the connection section 15.

When the above-described swaging section 9 extends the cylinder 14a of the drive mechanism 14, the outer roller 7 is moved while being guided by the guide mechanism 13 so that the outer roller 7 gets closer to the inner roller 6. As a result, the circumferential surfaces 6a and 7a of the inner and outer rollers 6 and 7 sandwich the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 therebetween. On the other hand, when the swaging section 9 contracts the cylinder 14a of the drive mechanism 14, the outer roller 7 is moved while being guided by the guide mechanism 13 so that the outer roller 7 moves away from the inner roller 6.

As shown in FIG. 5, the robot 5 is, for example, a typical 6-axis robot arm, and its base is connected to a fixing jig 5a. Meanwhile, the tip of the robot 5 is connected to the swaging section 9. The motor of each joint of the robot 5 is controlled based on a control signal supplied from the control unit 10.

The control unit 10 controls the motor of the main body 12 in the rotatable table 8, the pressurization/decompression unit 14b of the drive mechanism 14 in the swaging section 9, and the motor of each joint of the robot 5. Details of the control will be described later. Note that the control unit 10 according to this exemplary embodiment controls the rotatable table 8 and the robot 5 in cooperation in an interlocking manner.

Next, a swaging method according to this exemplary embodiment is explained. Note that the below-explained swaging method may be performed by using hardware resources and/or software resources.

Firstly, an operator disposes the tubular body 2 between the recessed parts 11h and 11k of the first and second fixing part 11a and 11b of the rotatable table 8, and drives the first and second drive mechanisms 11c and 11d and thereby fixes the tubular body 2 by the recessed parts 11h and 11k of the first and second fixing part 11a and 11b. Then, the operator places the circumferential edge 3a of the end plate 3 on the flange 2b of the tubular body 2 so that the opening 2a on the top of the tubular body 2 is closed.

Next, as shown in FIG. 2, the control unit 10 disposes the inner roller 6 inside the tubular body 2 by controlling the robot 5 and thereby brings the circumferential surface 6a of the inner roller 6 into contact with the rising part 3c of the end plate 3, and disposes the outer roller 7 outside the tubular body 2. In this process, the control unit 10 makes the pushing mechanism 16 push the planar section 3b of the end plate 3.

Next, the control unit 10 rotates the tubular body 2 and the end plate 3 by controlling the motor of the drive mechanism 12c in the rotatable table 8.

Next, the control unit 10 extends the cylinder 14a of the drive mechanism 14 by controlling the pressurization/decompression unit 14b of the drive mechanism 14 in the swaging section 9 and thereby moves the outer roller 7 toward the inner roller 6, and sandwiches the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 by the circumferential surfaces 6a and 7a of the inner and outer rollers 6 and 7.

Then, the control unit 10 controls the robot 5 and thereby moves the inner and outer rollers 6 and 7 so that they conform the rotating tubular body 2 and the end plate 3, i.e., move the inner and outer rollers 6 and 7 along the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3.

Note that FIG. 7 shows a positional relation among the tubular body, and the inner and outer rollers 6 and 7 when the tubular body 2 is rotated. In particular, FIG. 7 shows a positional relation until the tubular body 2 rotates 180°.

As shown in FIG. 7, the control unit 10 controls the rotatable table 8 and the robot 5 in cooperation and thereby controls the positions of the inner and outer rollers 6 and 7 so that the straight line L1 is disposed on a normal N1 (of the outer circumferential surface) of the tubular body 2 that passes through a place (processing point P1) where the tubular body 2 is sandwiched by the circumferential surfaces 6a and 7a of the inner and outer rollers 6 and 7 even when the tubular body 2 and the end plate 3 are rotated.

In other words, the control unit 10 controls the positions of the inner and outer rollers 6 and 7 so that the rotation shafts 6b and 7b of the inner and outer rollers 6 and 7 are disposed roughly in parallel with a surface (i.e., a line in the strict sense) where the tubular body 2 is sandwiched by the circumferential surfaces 6a and 7a of the inner and outer rollers 6 and 7 as viewed in the front/back direction of the swaging section 9, and the direction in which the outer roller 7 moves toward the inner roller 6 is roughly perpendicular to the surface where the tubular body 2 is sandwiched by the circumferential surfaces 6a and 7a as viewed in the vertical direction of the swaging section 9.

As a result, the circumferential surface 6a of the inner roller 6 roughly comes into contact with the surface of the rising part 3c (i.e., with the line in the rising part 3c in the strict sense) of the end plate 3, and the circumferential surface 7a of the outer roller 7 roughly comes into contact with the outer circumferential surface (i.e., with the line in the outer circumferential surface in the strict sense) of the tubular body 2. Further, the extending/contacting direction of the cylinder 14a of the drive mechanism 14 is roughly perpendicular to the tubular body 2. Therefore, the extending force by the cylinder 14a can be reliably transferred to the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3.

Note that as shown in FIG. 3, a rotation axis AX4 of the robot 5 preferably passes through a processing point P1 and extends in a direction in which the rotation shaft 6b of the inner roller 6 extends. As a result, it is possible to control the positions of the inner and outer rollers 6 and 7 so that the straight line L1 can be easily disposed on the normal N1 that passes through the processing point P1 even when the tubular body 2 and the end plate 3 are rotated.

Further, when the tubular body 2 is one that is manufactured by swaging opened ends of a roughly U-shaped steel plate, the swaged part is present on the outer circumferential surface of the tubular body 2. Therefore, the swaging device 1 preferably has a configuration in which when the outer roller 7 comes to the swaged part, the outer roller 7 can excellently get over the swaged part.

Therefore, in this exemplary embodiment, the swaging device 1 includes a pressure adjustment unit 14a that adjusts the force for pushing the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 in the outer roller 7 to a value equal to or lower than a predetermined threshold between the cylinder 14a and the pressurization/decompression unit 14b as shown in FIG. 2. As a result, it is possible to make the outer roller 7 get over the swaged part of the tubular body 2 while pushing the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 with an appropriate pressure.

As described above, the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 are swaged together by sandwiching the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 by the inner and outer rollers 6 and 7 while rotating the tubular body 2 and the end plate 3.

As described above, in the above-described swaging device 1 and the swaging method according to this exemplary embodiment, the force for pushing the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 exerted by the outer roller 7 is roughly equal to the force acting to push back the outer roller 7 exerted by the inner roller 6, and their reactive forces act on the robot 5 so that they cancel out each other. As a result, the reactive force is not substantially transferred to the robot 5. Therefore, there is no need to construct the robot 5 with a strong structure, thus making it possible to simplify the robot 5 and to contribute to a reduction in the cost thereof.

In addition, since the inner and outer rollers 6 and 7 are moved by using the robot 5 so that they conform to the rotating tubular body 2 and the end plate 3, the conforming mechanism (or copying mechanism) of conventional swaging devices can be omitted, thus simplifying the swaging device.

Further, since the grasping parts 11f and 11i of the first and second fixing part 11a and 11b according to this exemplary embodiment can be replaced according to the shape of the tubular body 2, the swaging device 1 has a high general-purpose property.

Further, in this exemplary embodiment, since the rotatable table 8 and the robot 5 are controlled in cooperation, the operating range of the robot 5 can be narrowed, thus contributing to a reduction in the size of the robot.

Note that FIGS. 8 and 9 show other tubular bodies or the like that can be swaged by the swaging device 1 according to this exemplary embodiment. The swaging device 1 according to this exemplary embodiment controls the positions of the inner and outer rollers 6 and 7 by using the robot 5. Therefore, even when the outer circumferential surface of the tubular body 2 is inclined inward or outward (i.e., even when the tubular body 2 is a frustum) as shown in FIG. 8, the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 can be swaged together by inclining the rotation axis AX4 of the robot 5 with respect to the axis that extends in the height direction of the tubular body 2.

Further, even when a part of the opened end of the tubular body 2 is inclined with respect to a surface S1 perpendicular to the axis extending in the height direction of the tubular body 2 as shown in FIG. 9, the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 can be still swaged together by inclining the rotation axis AX4 of the robot 5 with respect to the axis that extends in the height direction of the tubular body 2.

Second Exemplary Embodiment

In this exemplary embodiment, a configuration in which the outer roller 7 includes a first roller for a coarse process and a second roller for a finishing process as in the case of a typical swaging device is explained. Note that FIGS. 10 and 11 are plan views showing a swaging section according to this exemplary embodiment. FIG. 12 schematically shows a flow of a swaging process according to this exemplary embodiment.

As shown in FIGS. 10 and 11, a fundamental configuration of a swaging section 20 according to this exemplary embodiment is roughly identical to that of the swaging section 9 according to the first exemplary embodiment, and therefore duplicated explanations thereof are omitted. However, two swaging sections 9 are arranged roughly in a V-shape as viewed in the direction in which the rotation shaft 6b of the inner roller 6 extends. Note that the following explanations of the swaging section 20 are given with reference to the swaging section 20 shown in FIGS. 10 and 11.

A connection section 21 in this exemplary embodiment is formed roughly in a V-shape as viewed in the vertical direction of the swaging section 20. Further, a first guide mechanism 23 and a cylinder 24 of a first drive mechanism are provided in the connection section 21 so that a first roller 22 can be moved toward the inner roller 6. Further, a second guide mechanism 26 and a cylinder 27 of a second drive mechanism are provided in the connection section 21 so that a second roller 25 can be moved toward the inner roller 6. Note that the first and second rollers 22 and 25 are disposed at roughly the same height as each other in the vertical direction of the swaging section 20.

As a result, as viewed from the vertical direction of the swaging section 20, a straight line L2 that is perpendicular to the rotation shaft 6b of the inner roller 6 and connects a rotation axis 22a of the first roller 22 with the rotation shaft 6b of the inner roller 6 and a straight line L3 that is perpendicular to the rotation shaft 6b of the inner roller 6 and connects a rotation axis 25a of the second roller 25 with the rotation shaft 6b of the inner roller 6 are perpendicular to each other on the rotation shaft 6b of the inner roller 6.

The above-described swaging section 20 can rotate around the rotation axis AX4 of the robot 5, and rotates around the rotation axis AX4 according to the progress of the swaging process. That is, the first and second rollers 22 and 25 revolve around the rotation axis AX4. It should be noted that the rotation axis AX4 of the robot 5 according to this exemplary embodiment passes through a place (processing point P2) where the tubular body 2 is sandwiched by the circumferential surface 6a of the inner roller 6 and the circumferential surface 22b of the first roller 22, and extends in a direction in which the rotation shaft 6b of the inner roller 6 extends.

When a coarse process shown in FIGS. 12(a) to 12(c) is performed, the control unit 10 disposes the straight line L2 on the normal N2 (of the outer circumferential surface) of the tubular body 2 that passes through the processing point P2 by controlling the position of the swaging section 20 using the robot 5 and rotating the swaging section 20 around the rotation axis AX4.

Then, the control unit 10 extends the cylinder 24 of the first drive mechanism and thereby moves the first roller 22 toward the inner roller 6 while rotating the rotatable table 8. Note that the control unit 10 controls the robot 5 and thereby moves the inner roller 6 and the first roller 22 so that the state where the straight line L2 is disposed on the normal N2 of the tubular body 2 passing through the processing point P2 is maintained.

Next, when a finishing process shown in FIGS. 12(d) and 12(e) is performed, the control unit 10 disposes the straight line L3 on the normal N3 (of the outer circumferential surface) of the tubular body 2 that passes through a place (processing point P3) where the tubular body 2 is sandwiched by the circumferential surface 6a of the inner roller 6 and the circumferential surface 25b of the second roller 25 by controlling the position of the swaging section 20 using the robot 5 and rotating the swaging section 20 around the rotation axis AX4.

Then, the control unit 10 extends the cylinder 27 of the second drive mechanism and thereby moves the second roller 25 toward the inner roller 6 while rotating the rotatable table 8. Note that the control unit 10 controls the robot 5 and thereby moves the inner roller 6 and the second roller 25 so that the state where the straight line L3 is disposed on the normal N3 of the tubular body 2 passing through the processing point P3 is maintained.

As described above, this exemplary embodiment makes it possible to select the first roller 22 for the coarse process and the second roller 22 for the finishing process by controlling the robot 5, thus improving the productivity. In addition, the common inner roller 6 can be used for both the coarse process and the finishing process.

The present invention is not limited to the above-described exemplary embodiments and they can be modified as appropriate without departing the spirit and scope of the present invention.

Although the above-described exemplary embodiments are explained while defining the vertical direction, the left/right direction, and the front/back direction for clarifying the explanations, they may be changed as appropriate according to the use of the swaging device.

Although the rotatable table 8 is rotated in the above-described exemplary embodiments, swaging may be performed by moving the cramping section along the flange 2b of the tubular body 2 and the circumferential edge 3a of the end plate 3 by using the robot 5 without rotating the rotatable table 8.

From the invention thus described, it will be obvious that the embodiments of the invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims.

SWAGING DEVICE AND SWAGING METHOD

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