The present invention relates to a spinning forming device for forming a plate in a desired shape while rotating the plate.
Conventionally known is a spinning forming device designed to transform a plate by pressing a processing tool against the plate while rotating the plate. The spinning forming device normally includes a mandrel (shaping die) attached to a rotating shaft and performs forming in such a manner that the plate is pressed against the mandrel by the processing tool.
In recent years, proposed is a spinning forming device designed to perform spinning forming while locally heating the plate. For example, as a spinning forming device for a titanium alloy, PTL 1 discloses a spinning forming device configured such that a portion (transform target portion) of the plate which is pressed against the mandrel by a spatula (processing tool) is heated by high frequency induction heating.
As a heater suitable for the spinning forming device, the inventors of the present invention have developed a heater including a coil portion extending in a rotational direction of the plate and having a doubled circular-arc shape facing the plate (see PTL 2). By using such a heater, local heating of the transform target portion of the plate can be continuously performed in the rotational direction of the plate. Thus, excellent forming can be realized.
PTL 1: Japanese Laid-Open Patent Application Publication No. 2011-218427
PTL 2: International Publication No. 2014/024384
The inventors of the present invention have newly found in recent studies that when the processing tool is pressed against the transform target portion, an outer peripheral original portion including the transform target portion is inclined in some cases. According to the above heater including the coil portion having the doubled circular-arc shape, the coil portion is parallel to the plate before the processing tool is pressed against the plate. Therefore, if the outer peripheral original portion is inclined, a distance from the coil portion to the outer peripheral original portion becomes nonuniform. Thus, heating by the heater may become inadequate, or the inclined outer peripheral original portion may contact the coil portion of the heater in some cases.
An object of the present invention is to provide a spinning forming device capable of appropriately maintaining a positional relation between an outer peripheral original portion of a plate and a coil portion of a heater even when the outer peripheral original portion is inclined.
To solve the above problems, a spinning forming device of the present invention includes: a rotating shaft that rotates a plate to be formed; a processing tool that presses a transform target portion of the plate to transform the plate; a heater that locally heats the transform target portion by induction heating and includes a coil portion extending in a circumferential direction of the rotating shaft and having a doubled circular-arc shape facing the plate; a measuring unit that measures distances each from the coil portion to an outer peripheral original portion of the plate at a plurality of measurement points distributed in the circumferential direction of the rotating shaft, the outer peripheral original portion including the transform target portion; an inclining device that inclines the heater relative to a direction from the rotating shaft toward the processing tool; and a controller that controls the inclining device based on a measurement result of the measuring unit such that an angle difference between the coil portion and the outer peripheral original portion becomes not more than a predetermined angle.
According to the above configuration, the distance from the coil portion of the heater to the outer peripheral original portion of the plate can be kept substantially constant. As a result, even when the outer peripheral original portion is inclined, the positional relation between the outer peripheral original portion and the coil portion can be appropriately maintained.
For example, the spinning forming device may be configured such that: the heater is disposed at a position displaced from a position that is right opposite to the processing tool across the rotating shaft; and the inclining device swings the heater around a swing axis extending in a radial direction of the rotating shaft.
For example, the spinning forming device may be configured such that: the heater is disposed at a position that is right opposite to the processing tool across the rotating shaft; and the inclining device swings the heater around a swing axis extending in a direction orthogonal to a radial direction of the rotating shaft.
For example, the spinning forming device may be configured such that the controller controls the inclining device such that an absolute value of a difference between the distances measured at the plurality of measurement points becomes not more than a threshold.
For example, the spinning forming device may be configured such that the measuring unit includes a plurality of distance sensors disposed so as to be spaced apart from one another in the circumferential direction of the rotating shaft.
For example, the spinning forming device may be configured such that the heater is at least one of a rear-side heater disposed at an opposite side of the processing tool across the plate and a front-side heater disposed at a same side as the processing tool relative to the plate.
The spinning forming device may further includes a heat station to which the heater is coupled and in which an AC power supply circuit is formed, wherein the inclining device may incline the heater through the heat station. According to this configuration, since the heater is inclined together with the heat station, the heater can be strongly held by the heat station. As a result, even if a high current flows through the coil portion of the heater, and a high attractive force and a high repulsive force act on the heater, deformation of the heater can be suppressed.
The spinning forming device may further include a receiving jig attached to the rotating shaft and supporting a central portion of the plate. For example, it is presumed that when the mandrel is used, the inclination of the outer peripheral original portion of the plate is caused mainly by elastic deformation of the plate. On the other hand, when the receiving jig is used instead of the mandrel, an overhanging portion of the plate which portion overhangs from the receiving jig (i.e., a portion other than the central portion supported by the receiving jig) becomes a cantilever, so that the inclination of the outer peripheral original portion of the plate becomes larger by deflection of the overhanging portion. Therefore, when such receiving jig is used, the effects of the present invention can be remarkably obtained.
According to the present invention, even when the outer peripheral original portion of the plate is inclined, the positional relation between the outer peripheral original portion and the coil portion of the heater can be appropriately maintained.
An axial direction of the rotating shaft 21 (i.e., a direction in which the center axis 20 extends) is a vertical direction in the present embodiment. However, the axial direction of the rotating shaft 21 may be a horizontal direction or an oblique direction. A lower portion of the rotating shaft 21 is supported by a base 11. The rotating shaft 21 is rotated by a motor, not shown. An upper surface of the rotating shaft 21 is fiat, and the receiving jig 22 is fixed to the upper surface of the rotating shaft 21.
The plate 9 is, for example, a flat circular plate. However, the shape of the plate 9 may be a polygonal shape or an oval shape. The plate 9 is not necessarily flat over the entirety. For example, the central portion 91 of the plate 9 may be thicker than a peripheral edge portion of the plate 9, or the entire plate 9 or a part of the plate 9 may be processed in advance to have a tapered shape. A material of the plate 9 is not especially limited and is, for example, a titanium alloy.
The receiving jig 22 has a size within a circle defined by a forming start position of the plate 9. For example, in a case where the receiving jig 22 has a disc shape, a diameter of the receiving jig 22 is equal to or smaller than a diameter of the circle defined by the forming start position of the plate 9. Unlike conventional mandrels, the plate 9 is not transformed by being pressed against a radially outer side surface of the receiving jig 22.
The fixing jig 31 is attached to a pressurizing rod 32. The pressurizing rod 32 is rotatably supported by a supporting portion 33. The supporting portion 33 is driven by a driving portion 34 in an upward/downward direction. The driving portion 34 is attached to a frame 12 disposed above the rotating shaft 21. It should be noted that the fixing jig 31 may be omitted, and the plate 9 may be directly fixed to the receiving jig 22 by, for example, bolts.
In the present embodiment, the processing tool 10 that presses the transform target portion 92 of the plate 9 is disposed above the plate 9, and the plate 9 is processed by the processing tool 10 in a downwardly opening shape that accommodates the receiving jig 22. To be specific, an upper surface of the plate 9 is a front surface, and a lower surface of the plate 9 is a rear surface. However, the processing tool 10 may be disposed under the plate 9, and the plate 9 may be processed by the processing tool 10 in an upwardly opening shape that accommodates the fixing jig 31. To be specific, the lower surface of the plate 9 may be the front surface, and the upper surface of the plate 9 may be the rear surface.
The processing tool 10 is moved by a first radial direction movement mechanism 14 in a radial direction of the rotating shaft 21 and is also moved by a first axial direction movement mechanism 13 through the first radial direction movement mechanism 14 in the axial direction of the rotating shaft 21. The first axial direction movement mechanism 13 extends so as to couple the base 11 and the frame 12. In the present embodiment, used as the processing tool 10 is a roller that follows the rotation of the plate 9 to rotate. However, the processing tool 10 is not limited to the roller and may be, for example, a spatula.
The rear-side heater 4 is disposed at an opposite side of the processing tool 10 across the plate 9, and the front-side heater 5 is disposed at the same side as the processing tool 10 relative to the plate 9. In the present embodiment, the rear-side heater 4 and the front-side heater 5 are coupled to a common heat station 6. The rear-side heater 4 and the front-side heater 5 face each other in the axial direction of the rotating shaft 21. The heat station 6 is disposed outside the heaters 4 and 5 in the radial direction of the rotating shaft 21.
The rear-side heater 4 and the front-side heater 5 are moved by a second radial direction movement mechanism 16 through the heat station 6 in the radial direction of the rotating shaft 21 and are also moved by a second axial direction movement mechanism 15 through the heat station 6 and the second radial direction movement mechanism 16 in the axial direction of the rotating shaft 21. The second axial direction movement mechanism 15 extends so as to couple the base 11 and the frame 12.
As shown in
The connection boxes 61 and 62 are electrically connected to each other through the electric conducting pipe 41 of the rear-side heater 4 and the electric conducting pipe 51 of the front-side heater 5. To be specific, an alternating current flows from one of the connection boxes 61 and 62 to the other through the electric conducting pipes 51 and 41. A frequency of the alternating current is not especially limited but is desirably a high frequency of 5 k to 400 kHz. To be specific, the induction heating performed by the rear-side heater 4 and the front-side heater 5 is desirably high frequency induction heating.
The connection boxes 61 and 62 are provided with cooling liquid ports 63 and 64, respectively. A cooling liquid is supplied to one of the connection boxes 61 and 62 through the cooling liquid port (63 or 64) and circulates through the electric conducting pipes 51 and 41. After that, the cooling liquid is discharged from an inside of the other of the connection boxes 61 and 62 through the cooling liquid port (64 or 63). By this circulation of the cooling liquid through the electric conducting pipes 51 and 41, a large current (such as 1,000 to 4,000 A) can flow through the electric conducting pipes 51 and 41.
As shown in
The electric conducting pipe 41 includes a coil portion 44 and a pair of lead portions 42 and 43. The coil portion 44 extends in a circumferential direction of the rotating shaft 21 and has a doubled circular-arc shape facing the plate 9. The lead portions 42 and 43 extend from a middle of the coil portion 44 outward in the radial direction of the rotating shaft 21. To be specific, the coil portion 44 includes one inner circular-arc portion 45 and two outer circular-arc portions 46 spreading at both sides of the lead portions 42 and 43. An opening angle (angle between both end portions) of the coil portion 44 is, for example, 60° to 120° . The lead portions 42 and 43 are connected to the connection boxes 61 and 62 of the heat station 6, respectively.
The rear-side heater 4 also includes one first core 47 and two second cores 48. The first core 47 covers the inner circular-arc portion 45 of the coil portion 44 from an opposite side of the plate 9. The second cores 48 cover the outer circular-arc portions 46 from the opposite side of the plate 9. The first core 47 is intended to collect magnetic flux generated around the inner circular-arc portion 45, and the second cores 48 are intended to collect magnetic flux generated around the outer circular-arc portions 46. The first core 47 and the second cores 48 are supported by the supporting plate 40 through an insulating member, not shown.
As shown in
The electric conducting pipe 51 includes a coil portion 54 and a pair of lead portions 52 and 53. The coil portion 54 extends in the circumferential direction of the rotating shaft 21 and has a doubled circular-arc shape facing the plate 9. The lead portions 52 and 53 extend from a middle of the coil portion 54 outward in the radial direction of the rotating shaft 21. To be specific, the coil portion 54 includes one inner circular-arc portion 55 and two outer circular-arc portions 56 spreading at both sides of the lead portions 52 and 53. An opening angle (angle between both end portions) of the coil portion 54 is, for example, 60° to 120° . The lead portions 52 and 53 are connected to the connection boxes 61 and 62 of the heat station 6, respectively. To be specific, the electric conducting pipe 51 of the front-side heater 5 is connected to the connection boxes 61 and 62 in parallel with the electric conducting pipe 41 of the rear-side heater 4. However, the electric conducting pipe 51 may be connected to the connection boxes 61 and 62 in series with the electric conducting pipe 41.
The front-side heater 5 also includes one first core 57 and two second cores 58. The first core 57 covers the inner circular-arc portion 55 of the coil portion 54 from the opposite side of the plate 9. The second cores 58 cover the outer circular-arc portions 56 from the opposite side of the plate 9. The first core 57 is intended to collect magnetic flux generated around the inner circular-arc portion 55, and the second cores 58 are intended to collect magnetic flux generated around the outer circular-arc portions 56. The first core 57 and the second cores 58 are supported by the supporting plate 50 through an insulating member, not shown.
The relative positions of the heaters 4 and 5 and the processing tool 10 are not especially limited as long as they are located on substantially the same circumference around the center axis 20 of the rotating shaft 21. As shown in
Referring back to
More specifically, since a relative positional relation among the heaters 4 and 5 and the processing tool 10 is as shown in
The movement mechanisms 13 and 14 for the processing tool 10, the movement mechanisms 15 and 16 for the heaters 4 and 5, and the inclining device 7 are controlled by a controller 17 shown in
In the present embodiment, as shown in
More specifically, in a plan view, the distance sensors 81 are disposed on a center line of the coil portion 54 so as to sandwich the coil portion 54 (in other words, the distance sensors 81 are disposed at both respective sides of the coil portion 54). The bracket 85 includes: a post 86 standing on the supporting plate 50; and arms 87 each extending from the post 86 to the distance sensor 81.
By the above-described configuration, the relative positions of the distance sensors 81 and the coil portion 54 never change. To be specific, the distance sensors 81 also serve as a measuring unit 8 that measures distances each from the coil portion 54 to an outer peripheral original portion 93 of the plate 9 at a plurality of (in the present embodiment, two) measurement points distributed in the circumferential direction of the rotating shaft 21. The outer peripheral original portion 93 includes the transform target portion 92.
The controller 17 controls the inclining device 7 based on measurement results of the distance sensors 81 such that an angle difference between the coil portion 54 and the outer peripheral original portion 93 becomes not more than a predetermined angle (five degrees, for example). Specifically, the controller 17 controls the inclining device 7 such that an absolute value of a difference between the distances measured at the plurality of measurement points becomes not more than a threshold. For example, the controller 17 controls the inclining device 7 so as to satisfy the following formula where A denotes a distance that is measured by one of the distance sensors 81 and is from one end of the coil portion 54 to the outer peripheral original portion 93, B denotes a distance that is measured by the other distance sensor 81 and is from the other end of the coil portion 54 to the outer peripheral original portion 93, and α denotes the threshold.
|A−B|≦α
The measuring unit 8 does not necessarily have to be constituted by a plurality of distance sensors 81. For example, an imaging system including a camera and an image processor may be used as the measuring unit 8, and distances at a plurality of measurement points may be measured by image processing.
As explained above, according to the spinning forming device 1 of the present embodiment, the distance from the coil portion 44, 54 of the heater 4, 5 to the outer peripheral original portion 93 of the plate 9 can be kept substantially constant. As a result, even when the outer peripheral original portion 93 is inclined as shown in
The present invention is not limited to the above embodiment, and various modifications may be made within the scope of the present invention.
For example, as shown in
According to a layout shown in
As shown in
The spinning forming device 1 does not necessarily have to include both the rear-side heater 4 and the front-side heater 5 and may include only one of the rear-side heater 4 and the front-side heater 5. To be specific, the heater of the present invention may be at least one of the rear-side heater 4 and the front-side heater 5.
The inclining device 7 does not necessarily have to incline at least one of the rear-side heater 4 and the front-side heater 5 through the heat station 6. For example, the inclining device 7 may be disposed between the heat station 6 and each of the rear-side heater 4 and the front-side heater 5 so as to be able to individually incline the rear-side heater 4 and the front-side heater 5. In this case, the inclining device 7 may be constituted by: a supporting portion which supports swingably the supporting plate (40 or 50) of the heater (4 or 5); and an actuator (such as an electric-powered cylinder) that drives the supporting plate.
In the above embodiment, the receiving jig 22 is used. However, instead of the receiving jig 22, a mandrel may be adopted. When the mandrel is used, the transform target portion 92 of the plate 9 is pressed against the mandrel by the processing tool 10, so that the inclination of the outer peripheral original portion 93 becomes small. On the other hand, when the receiving jig 22 is used, the transform target portion 92 of the plate 9 is pressed by the processing tool 10 in the air away from the receiving jig 22, so that the inclination of the outer peripheral original portion 93 becomes large. Therefore, the spinning forming device 1 including the receiving jig 22 can remarkably obtain the effects of the present invention.
The present invention is useful when performing spinning forming of plates made of various materials.
Number | Date | Country | Kind |
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2014-080696 | Apr 2014 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2015/001905 | 4/3/2015 | WO | 00 |