The present disclosure relates to a centrifugal casting mold and a centrifugal casting mold assembly device.
A centrifugal casting method has been known as a method for shaping a cylindrical cast. The centrifugal casting method is a method of shaping a cylindrical cast on the inner periphery of a mold having a cylindrical shape by pouring molten metal into the mold while the mold is rotated and by pressurizing the molten metal by using centrifugal force. The mold used in such a centrifugal casting method is, for example, a mold disclosed in Patent Literature 1 below. The mold disclosed in Patent Literature 1 includes a mold body having a cylindrical shape and a lid member that is detachably mounted at one end part of the mold body. A screw ring having a circular ring shape and having a male screw part on the outer peripheral surface is fixed to one end surface of the mold body. A flange part having a female screw part on the inner peripheral surface is provided at the lid member. The lid member is fastened and assembled to the one end part of the mold body when the female screw part formed on the inner peripheral surface of the flange part of the lid member is screwed to the male screw part formed on the outer peripheral surface of the screw ring of the mold body.
When the mold body is assembled to the lid member by a fastening structure including a screw mechanism like the mold disclosed in Patent Literature 1, a process of fastening the lid member to the mold body is performed a worker by using a device or a hand. Thus, force of fastening the lid member to the mold body potentially varies between workers. Accordingly, when the force of fastening the lid member to the mold body varies in a weakening direction, the lid member cannot closely contact the mold body and a gap is potentially formed therebetween. When molten metal is poured into the mold body with such a gap formed between the mold body and the lid member, such a failure that the molten metal externally leaks through the gap formed between the mold body and the lid member or the lid member is firmly fixed when the molten metal cools and thus the gap formation is not preferable.
The present disclosure is intended to provide a centrifugal casting mold in which a mold body can more reliably closely contact a lid member, and an assembly device for the centrifugal casting mold.
A centrifugal casting mold according to an aspect of the present disclosure is used for centrifugal casting and includes a mold body formed in a cylindrical shape and a lid member that is detachably assembled to an end part of the mold body in an axial direction. The lid member includes a lid body that is attached to an opening part formed at the end part of the mold body, a fitting part that is fitted to the mold body, and an elastic force application part that applies elastic force to the lid body in a direction in which the lid body closely contacts the mold body.
With this configuration, the lid body can closely contact the mold body with the elastic force of the elastic force application part, and thus the lid member can more reliably closely contact the mold body than in a case of a conventional mold in which the lid member is mounted on the mold body by using a screw fastening structure.
In the above-described centrifugal casting mold, a protrusion part protruding outward may be formed as the fitting part on an outer peripheral surface of the lid member, a groove part into which the protrusion part of the lid member is inserted may be formed at the end part of the mold body, and the protrusion part of the lid member may be fitted to the groove part of the mold body.
With this configuration, a fitting structure of the mold body and the lid member can be easily achieved.
In the above-described centrifugal casting mold, the groove part may include a first extending part having an opening part at an end face of the mold body and formed to extend in a direction parallel to the axial direction of the mold body and a second extending part formed to extend in a circumferential direction of the mold body from an end part opposite to the opening part of the first extending part, the lid member may further include a movable member including the fitting part, the movable member may be formed separately from the lid body and can be displaced relative to the lid body in the axial direction of the mold body, the protrusion part of the lid member may be fitted to the second extending part of the groove part of the mold, the elastic force application part may apply elastic force to the lid body and the movable member in a direction in which the lid body separates from the movable member in the axial direction of the mold body, and the mold may have a mechanism that the lid body closely contacts the mold body with the elastic force applied to the lid body by the elastic force application part and the fitting part is pressed to an inner wall surface of the second extending part with the elastic force applied to the movable member by the elastic force application part.
With this configuration, the fitting part is unlikely to be come off the second extending part of the groove part because of the elastic force applied to the movable member by the elastic force application part. As a result, the lid member is unlikely to fall off the mold body.
In the above-described centrifugal casting mold, a concave part into which the protrusion part is inserted may be formed at the inner wall surface of the second extending part that the protrusion part of the movable member contacts.
With this configuration, even when the protrusion part of the lid member is displaced in a direction in which the protrusion part comes off the second extending part of the groove part, the protrusion part of the lid member is prevented from coming off because the protrusion part is unlikely to come off the concave part. Thus, the lid member is more unlikely to fall off the mold body.
In the above-described centrifugal casting mold, a plurality of the protrusion parts may be formed on the outer peripheral surface of the lid member, and a plurality of groove parts in a number larger than the number of the protrusion parts may be formed at the end part of the mold body.
With this configuration, the number of groove parts into which each protrusion part can be inserted is larger than in a case in which the number of the protrusion parts and the number of the groove parts are equal to each other. As a result, the lid member can be easily assembled to the mold body.
An assembly device for the above-described centrifugal casting mold includes an attachment-detachment device configured to attach and detach the lid member to and from the end part of the mold body, and a control device configured to control the attachment-detachment device. The attachment-detachment device includes a grasping unit configured to grasp the lid member, and an image capturing unit provided at the grasping unit. When attaching the lid member to the mold body, the control device grasps the lid member with the grasping unit, and then captures an image of the end face of the mold body with the image capturing unit and detects the position of the mold body relative to the grasping unit based on image data obtained by the image capturing, and fits the fitting part of the lid member to the mold body by displacing the grasping unit based on the position of the mold body.
With this configuration, work of attaching the lid member to the mold body can be automatically performed by the attachment-detachment device, and thus convenience can be improved.
In the above-described centrifugal casting mold assembly device, the attachment-detachment device may further include a position detection unit configured to detect the position of the grasping unit relative to the mold body in the axial direction of the mold body, and the control device may fit the fitting part of the lid member to the mold body by further displacing the grasping unit based on the position of the grasping unit detected by the position detection unit.
With this configuration, the grasping unit can be more accurately displaced, and thus the lid member can be further accurately attached to the mold body.
In the above-described centrifugal casting mold assembly device, the control device may displace the grasping unit in a direction in which the fitting part of the lid member is fitted to the mold body, and then captures an image of the end face of the mold body with the image capturing unit, determine whether the fitting part of the lid member is fitted to the mold body based on image data obtained by the image capturing, and determine that the attachment of the lid member to the mold body is normally performed when having determined that the fitting part of the lid member is fitted to the mold body.
With this configuration, whether the process of attaching the lid member to the mold body is normally performed can be accurately detected.
In the above-described centrifugal casting mold assembly device, when detaching the lid member from the mold body, the control device may capture an image of the end face of the mold body with the image capturing unit, detect the position of the mold body relative to the grasping unit based on image data obtained by the image capturing, grasp the lid member with the grasping unit by displacing the grasping unit based on the position of the mold body, and then cancel a state in which the fitting part of the lid member is fitted to the mold body by further displacing the grasping unit.
With this configuration, work of detaching the lid member from the mold body can be automatically performed by the attachment-detachment device, and thus convenience can be improved.
An embodiment of a centrifugal casting mold and a centrifugal casting mold assembly device will be described below with reference to the accompanying drawings. To facilitate understanding of the description, any identical constituent components in the drawings are denoted by the same reference sign when possible, and duplicate description thereof is omitted.
First, a mold 10 of the present embodiment will be described below with reference to
End parts 200 and 201 of the mold body 20 are both opened. The one lid member 30 is attached to an opening part of the one end part 200 of the mold body 20. The lid member 30 is fastened and fixed to the one end part 200 of the mold body 20 by a bolt 31. The other lid member 40 is attached to an opening part of the other end part 201 of the mold body 20. The lid member 40 is detachably attached to the other end part 201 of the mold body 20.
The mold 10 illustrated in
The structures of the mold body 20 and the lid member 40 will be described below in detail.
As illustrated in
The cylindrical member 21 is formed in a cylindrical shape about the axis line m10 and formed to extend in the axial direction Ma. The cylindrical member 21 is a part into which molten metal is poured, in other words, a part in which a cast is shaped. A tapered surface 211 is formed at the inner wall surface of one end part 210 of the cylindrical member 21.
The stopper ring 22 is integrally fixed to the one end part 210 of the cylindrical member 21. The stopper ring 22 is formed in a cylindrical shape about the axis line m10. The stopper ring 22 is provided as a part to which the lid member 40 is attached. Specifically, a groove part 220 is formed at the stopper ring 22. The groove part 220 includes a first extending part 221 and a second extending part 222 and is formed in a J shape as a whole, the first extending part 221 having an opening part at an end face 202 of the stopper ring 22 and formed to extend in the axial direction Ma, the second extending part 222 being formed to extend in the circumferential direction Mc from an end part opposite to the opening part of the first extending part 221. The second extending part 222 has inner wall surfaces 222a and 222b extending in the circumferential direction Mc, and a concave part 222c is formed at the inner wall surface 222b disposed near the end face 202 of the stopper ring 22. As illustrated in
Note that, in the mold 10 of the present embodiment, the stopper ring 22 is a constituent component of the mold body 20. Accordingly, the end face 202 of the stopper ring 22 is an end face of the mold body 20, and thus the end face 202 is also referred to as “the end face 202 of the mold body 20” in the following description.
As illustrated in
The lid body 41 is formed in a substantially circular truncated cone shape about the axis line m10 and tapered in a direction from a proximal end part 410 to a distal end part 411 opposite thereto. When the lid member 40 is mounted on the mold body 20, a tilt surface 412 of the lid body 41 closely contacts the tapered surface 211 formed at the inner periphery of the cylindrical member 21 of the mold body 20 illustrated in
As illustrated in
The movable ring 43 is a member formed in a circular ring shape about the axis line m10 and fitted to the outer periphery of the cylindrical part 421 of the flange part 42. The length of the movable ring 43 in the axial direction Ma is shorter than the length of the cylindrical part 421 of the flange part 42 in the axial direction Ma. The movable ring 43 is formed separately from the lid body 41 and the flange part 42 and can be displaced relative to the lid body 41 and the flange part 42 in the axial direction Ma. In the present embodiment, the movable ring 43 corresponds to a movable member. An insertion hole 430 is formed through the movable ring 43 in a direction parallel to the axial direction Ma. A stepped bolt 44 is inserted into the insertion hole 430. A stepped part 431 that engages with a head 440 of the stepped bolt 44 in the axial direction Ma is formed at the inner wall surface of the insertion hole 430. The movable ring 43 is prevented from coming off the flange part 42 when the head 440 of the stepped bolt 44 engages with the stepped part 431 of the insertion hole 430 in the axial direction Ma. As illustrated in
As illustrated in
As illustrated in
Note that, as clearly understood from comparison between
A method of attaching the lid member 40 to the mold body 20 of the present embodiment will be described below.
When the lid member 40 is to be attached to the mold body 20, first, pressing force is applied to an end face of the movable ring 43 of the lid member 40, which is opposite to the end face 432, to press the movable ring 43 toward the flange part 42 against elastic force of the springs 46 so that the movable ring 43 of the lid member 40 closely contacts the flange part 42 as illustrated in
The above-described process of attaching the lid member 40 can be performed by, for example, a worker. In the present embodiment, the process of attaching the lid member 40 is automatically performed by an assembly device 50 as illustrated in
The configuration of the assembly device 50 will be specifically described below.
As illustrated in
The attachment-detachment device 60 is a robotic-arm device and performs attachment of the lid member 40 to the mold body 20 and detachment of the lid member 40 from the mold body 20. The attachment-detachment device 60 includes an arm unit 61 and a hand unit 62.
The arm unit 61 has what is called a six-axis vertical multi-joint structure including first to sixth joint parts 611 to 616 that are rotatable about first to sixth axes L1 to L6 illustrated in
The hand unit 62 is provided at a distal end part of the sixth joint part 616. The hand unit 62 is a part configured to grasp the lid member 40. Specifically, as illustrated in
As illustrated in
The pressing mechanism 80 includes a pressing unit 81 and a power generation unit 82.
The pressing unit 81 is attached to the hand unit 62 such that the pressing unit 81 can be relatively displaced in a direction illustrated with an arrow Hx. The Hx direction is a direction parallel to the sixth axis L6.
In the following description, a direction orthogonal to both the Hx direction and the Hz direction is referred to as an “Hy direction”. In the Hx direction, a direction from a proximal end part 623 to a distal end part 624 of the hand unit 62 is referred to as an “Hx1 direction”, and a direction from the distal end part 624 to the proximal end part 623 of the hand unit 62 is referred to as an “Hx2 direction”.
The power generation unit 82 applies force in the Hx direction to the pressing unit 81 by using force of compression air or the like. In the pressing mechanism 80, the pressing unit 81 is displaced in the Hx direction based on the force applied to the pressing unit 81 by the power generation unit 82, and accordingly, the click parts 621 and 622 can grasp the chuck groove 422 of the lid member 40 and the pressing unit 81 can press the end face of the movable ring 43 opposite to the end face 432.
The image capturing device 90 is fixed and attached to an outer periphery part of the proximal end part 623 of the hand unit 62. The image capturing device 90 is a camera or the like and generates image data by capturing an image of an image capturing region that is a front side of the hand unit 62. For example, when the lid member 40 is to be attached to the mold body 20, the image capturing device 90 captures an image of the end face 202 of the mold body 20 of the stopper ring 22 and generates image data of the image.
The position sensor 100 is an air-cylinder position sensor and includes a contact part 101. When receiving force in the Hx2 direction, the contact part 101 is pressed and displaced relative to the hand unit 62 in the Hx2 direction. The position sensor 100 is a sensor configured to output an on-signal based on the displacement of the contact part 101 in the Hx2 direction. Accordingly, the output signal from the position sensor 100 switches from an off-state to an on-state when the contact part 101 contacts the mold body 20 while the hand unit 62 is displaced in the Hx1 direction. Thereafter, the contact part 101 returns to an initial position illustrated in
The control device 70 illustrated in
Specifically, as illustrated in
The control device 70 includes, as functional elements achieved as the processor executes a computer program stored in the storage unit, an image data acquisition unit 71, a plane-directional position detection unit 72, a depth-directional position detection unit 73, an attachment-detachment control unit 74, an assembly determination unit 75, and an anomaly processing unit 76.
The image data acquisition unit 71 acquires image data by capturing an image of a front side region of the hand unit 62 with the image capturing device 90 and provides appropriate image processing to the acquired image data.
The plane-directional position detection unit 72 detects the position of an object existing on the front side of the hand unit 62, more specifically, the position of the object relative to the hand unit 62 based on the image data acquired by the image data acquisition unit 71. The plane-directional position detection unit 72 can accurately detect the position of an object in a plane including the Hy and Hz directions illustrated in
The depth-directional position detection unit 73 illustrated in
The attachment-detachment control unit 74 performs attachment of the lid member 40 to the mold body 20 and detachment of the lid member 40 from the mold body 20 by detecting the positions of the mold body 20 and the hand unit 62 with the plane-directional position detection unit 72 and the depth-directional position detection unit 73 and driving the attachment-detachment device 60 based on the detected positions.
The assembly determination unit 75 determines whether assembly of the lid member 40 to the mold body 20 is normally performed by using the image data acquired by the image data acquisition unit 71.
When it is determined that the attachment of the lid member 40 to the mold body 20 is not normally performed, the anomaly processing unit 76 executes processing corresponding to the anomaly, such as issuing of an alert from a notification unit 63 provided at the attachment-detachment device 60.
Specific procedures of processing of attaching the lid member 40 and processing of detaching the lid member 40 executed by the control device 70 will be described below.
Description will be first made on the procedure of processing of attaching the lid member 40 with reference to
As illustrated in
After the processing at step S10, the attachment-detachment control unit 74 drives the arm unit 61 of the attachment-detachment device 60 based on predetermined coordinate data to move the hand unit 62 closer to the lid member 40 to a position where the lid member 40 can be grasped (step S11).
After the processing at step S11, the attachment-detachment control unit 74 grasps the lid member 40 with the hand unit 62 by driving the hand unit 62 so that the first click part 621 and the second click part 622 are closed (step S12). Specifically, the attachment-detachment control unit 74 grasps the chuck groove 422 illustrated in
After the processing at step S12 as illustrated in
After the processing at step S13 as illustrated in
After step S14, the attachment-detachment control unit 74 moves the lid member 40 closer to the mold body 20 by driving the arm unit 61 of the attachment-detachment device 60 based on the position of the mold body 20 detected by the plane-directional position detection unit 72, more specifically, driving the arm unit 61 about the first axis L1 to the fifth axis L5 except for the sixth axis L6 (step S15). In this case, the attachment-detachment control unit 74 detects the positions of the groove parts 220 of the mold body 20 relative to the hand unit 62, in other words, the positions of the groove parts 220 of the mold body 20 relative to the lid member 40 in a rotational direction centered at the sixth axis L6 based on the image data of the end face 202 of the mold body 20 acquired by the image data acquisition unit 71. The attachment-detachment control unit 74 rotates the hand unit 62 about the sixth axis L6 so that the detected relative rotational position of the end face 202 of the mold body 20 reaches a predetermined rotational position. The predetermined rotational position is a position where the protrusion parts 450 of the lid member 40 face the first extending parts 221 of the groove parts 220 of the mold body 20 as illustrated in
After the processing at step S15 as illustrated in
Thereafter, when the output signal from the position sensor 100 switches from the off-state to the on-state, in other words, when the contact part 101 of the position sensor 100 moves to a position where the contact part 101 contacts the mold body 20, the depth-directional position detection unit 73 performs positive determination in the processing at step S17. In this case, the attachment-detachment control unit 74 drives the arm unit 61 to rotate the hand unit 62 about the sixth axis L6 (step S18) so that the protrusion parts 450 of the lid member 40 are inserted and fitted into the second extending parts 222 of the groove parts 220 of the mold body 20.
Subsequently, the assembly determination unit 75 determines whether the protrusion parts 450 of the lid member 40 are normally assembled to the groove parts 220 of the mold body 20 (step S19). The assembly determination unit 75 requests the image data acquisition unit 71 to acquire image data of the end face 202 of the mold body 20. The image data acquisition unit 71 captures an image of the end face 202 of the mold body 20 with the image capturing device 90 based on the request from the attachment-detachment control unit 74 and transmits image data of the image to the assembly determination unit 75. Accordingly, the assembly determination unit 75 can obtain, for example, such image data illustrated in
When the positional relation of the groove parts 220 of the mold body 20 and the stepped bolts 44 of the lid member 40 is a positional relation as illustrated in
Consider a case in which image data as illustrated in
After the lid member 40 is attached to the mold body 20 through the processing illustrated in
The procedure of processing of detaching the lid member 40 executed by the control device 70 will be described below with reference to
As illustrated in
When positive determination is performed in the processing at step S34, in other words, when the contact part 101 of the position sensor 100 moves to a position where the contact part 101 contacts the mold body 20, the attachment-detachment control unit 74 grasps the lid member 40 with the hand unit 62 by driving the hand unit 62 so that the first click part 621 and the second click part 622 are closed (step S35). In this case, after grasping the lid member 40 with the hand unit 62, the attachment-detachment control unit 74 drives the pressing mechanism 80 of the hand unit 62 to apply pressing force to the movable ring 43 of the lid member 40 so that the movable ring 43 is pressed toward the flange part 42 against elastic force of the springs 46. Accordingly, the movable ring 43 of the lid member 40 closely contacts the flange part 42 and fitting of the protrusion parts 450 of the lid member 40 to the groove parts 220 of the mold body 20 is canceled.
After the processing at step S35, the attachment-detachment control unit 74 drives the arm unit 61 to rotate the hand unit 62 about the sixth axis L6 (step S36) so that the protrusion parts 450 of the lid member 40 move to the first extending parts 221 of the groove parts 220 of the mold body 20. Thereafter, the attachment-detachment control unit 74 detaches the lid member 40 from the mold body 20 by further driving the arm unit 61 to move the hand unit 62 in the Hx2 direction illustrated in
After the processing at step S37, the attachment-detachment control unit 74 drives the arm unit 61 based on coordinate data to move the hand unit 62 to the cooling table (step S38). Then, the attachment-detachment control unit 74 cancels the grasping of the lid member 40 by the hand unit 62 (step S39), and then drives the arm unit 61 to retract the hand unit 62 to the predetermined standby position (step S40) and ends the series of processes illustrated in
According to the mold 10 and the assembly device 50 of the present embodiment described above, it is possible to obtain operations and effects listed at (1) to (9) below.
(1) The lid member 40 includes the lid body 41 that is attached to the opening part formed at the end part 201 of the mold body 20, each protrusion part 450 as the fitting part that is fitted to the mold body 20, and each spring 46 as the elastic force application part that applies elastic force to the lid body 41 in a direction in which the lid body 41 closely contacts the mold body 20. With this configuration, the lid body 41 can closely contact the mold body 20 with the elastic force of the springs 46, and thus the lid member 40 can more reliably closely contact the mold body 20 than in a case of a conventional mold in which the lid member is mounted on the mold body by using a screw fastening structure.
(2) As illustrated in
(3) As illustrated in
Note that the second extending part 222 preferably extends in a direction opposite to a direction in which the mold 10 rotates in centrifugal casting. Accordingly, the protrusion part 450 is unlikely to be come off the second extending part 222 when the mold 10 rotates, and as a result, the lid member 40 is unlikely to fall off the mold 10.
(4) As illustrated in
(5) As illustrated in
(6) When attaching the lid member 40 to the mold body 20, the control device 70 grasps the lid member 40 with the hand unit 62 of the attachment-detachment device 60 and then captures an image of the end face 202 of the mold body 20 with the image capturing device 90 and detects the position of the mold body 20 relative to the hand unit 62 based on image data obtained by the image capturing. Then, the control device 70 fits each protrusion part 450 of the lid member 40 to the mold body 20 by displacing the hand unit 62 based on the detected position of the mold body 20. With this configuration, work of attaching the lid member 40 to the mold body 20 can be automatically performed by the attachment-detachment device 60, and thus convenience can be improved.
(7) The attachment-detachment device 60 further includes the position sensor 100 configured to detect the position of the hand unit 62 relative to the mold body 20 in the axial direction Ma. The control device 70 fits each protrusion part 450 of the lid member 40 to the mold body 20 by further displacing the hand unit 62 based on the position of the hand unit 62 detected by the position sensor 100. With this configuration, the hand unit 62 can be more accurately displaced, and thus the lid member 40 can be more accurately attached to the mold body 20.
(8) The control device 70 displaces the hand unit 62 in a direction in which each protrusion part 450 of the lid member 40 is fitted to the mold body 20, and then captures an image of the end face 202 of the mold body 20 with the image capturing device 90 and determines whether each protrusion part 450 of the lid member 40 is fitted to the mold body 20 based on image data obtained by the image capturing. Then, the control device 70 determines that the attachment of the lid member 40 to the mold body 20 is normally performed when having determined each protrusion part 450 of the lid member 40 is fitted to the mold body 20. With this configuration, whether the process of attaching the lid member 40 to the mold body 20 is normally performed can be accurately detected.
(9) When detaching the lid member 40 from the mold body 20, the control device 70 captures an image of the end face 202 of the mold body 20 with the image capturing device 90 and detects the position of the mold body 20 relative to the hand unit 62 based on image data obtained by the image capturing. Then, the control device 70 grasps the lid member 40 with the hand unit 62 by displacing the hand unit 62 based on the detected position of the mold body 20, and then cancels a state in which each protrusion part 450 of the lid member 40 is fitted to the mold body 20 by further displacing the hand unit 62. With this configuration, work of detaching the lid member 40 from the mold body 20 can be automatically performed by the attachment-detachment device 60, and thus convenience can be improved.
Note that the above-described embodiment may be performed forms described below.
The shape of each groove part 220 formed at the mold body 20 is changeable as appropriate to an optional shape such as a V shape as long as each protrusion part 450 of the lid member 40 can be fitted to the groove part 220. Alternatively, the shape of each groove part 220 may be, for example, the shape of a slit having a cutout or the shape of a groove having a concave part. In this manner, the definition of each groove part of the present embodiment includes a slit and a recess.
The number of the protrusion parts 450 of the lid member 40 and the number of the groove parts 220 of the mold body 20 may be equal to each other.
The fitting structure for assembling the lid member 40 to the mold body 20 is changeable as appropriate. For example, a protrusion part may be provided at the mold body 20, a groove part into which the protrusion part is inserted may be provided at the lid member 40, and the lid member 40 may be assembled to the mold body 20 by fitting the protrusion part of the mold body 20 to the groove part of the lid member 40.
The process of attaching the lid member 40 to the mold body 20 may be performed by a worker with a hand without using the attachment-detachment device 60.
The present disclosure is not limited to the above-described specific examples. Those obtained by adding designing change to the above-described specific examples as appropriate by the skilled person in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Elements included in the above-described specific examples, and their disposition, conditions, shapes, and the like are not limited to those exemplarily described but may be changed as appropriate. Combination of elements included in the above-described specific examples may be changed as appropriate without technological inconsistency.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/047750 | 12/21/2020 | WO |