JP4628343B2 - Manufacturing method of cylindrical ring with bead - Google Patents

Description

  The present invention relates to a method of manufacturing a cylindrical ring with a bead that can be used, for example, as a reinforcing ring for a run-flat tire, a cylindrical ring with a bead manufactured by the method, and an aluminum alloy plate used in the method.

  A run-flat tire is a tire that can travel a certain distance even when a car tire is punctured and the air pressure is completely lost. For example, Patent Document 1 described below is one of the methods, and a tire called a metal reinforcing ring or support ring is installed on the outer periphery of a rim in the tire, and the tire is crushed by puncture. Is supported by this reinforcing ring to ensure a certain distance of travel.

JP-T-2001-519279

As described in Patent Document 1, this type of reinforcing ring has a plurality of beads (such as bump-like protrusions or stepped portions) bulging in the outer circumferential direction in the circumferential direction. As a manufacturing method of this reinforcing ring, the following methods have been proposed so far.
(1) A flat plate is rolled and formed into a cylindrical shape, and the ends are welded together to form a cylindrical ring, and overhang forming called hydroform (bulge forming) is added to this to bulge in the outer circumferential direction. The bead is formed in the circumferential direction.
(2) A flat plate is rolled and formed into a cylindrical shape, and the ends are welded to form a cylindrical ring. Spinning (squeezing) is applied to this to expand and expand the bead to form a bead. Or the part which was not diameter-reduced by reducing in diameter partially is left as a bead which expanded in the outer peripheral direction.
(3) A flat plate is press-molded to form a plate that has been beaded in the vertical direction, or a plate whose cross-section is beaded is formed by extrusion, and this is bent (by a roll or a press). Then, the ends are welded together.
(4) Using a bending roll having irregularities corresponding to the beads, beading is performed on a flat plate, and at the same time, a roll is bent to form a cylindrical ring, and the ends are welded.

  However, the method (1) has the disadvantages that the equipment is large and the initial investment is high, and the management of the pressurized medium (water, oil, etc.) is troublesome. The method (2) has the disadvantages that the cycle time is long and the productivity is poor. The method (3) has a drawback that the bending accuracy is poor because the bending is performed after the bead is formed. The method (4) has the disadvantage that the accuracy of bending is poor, as in (3).

  The present invention has been made in view of the problems of the conventional method of manufacturing a reinforcing ring, and manufactures a highly accurate reinforcing ring and a similar cylindrical ring with a bead at low cost and with high productivity. The purpose is to do.

  The method for manufacturing a cylindrical ring with a bead according to the present invention is such that, on the outer peripheral side of a closed cylindrical metal ring made of metal, the inner surface side is a molding surface and a groove for bead molding is formed along the circumferential direction of the molding surface. An electromagnetic forming coil is arranged on the inner peripheral side of the cylindrical material ring, and an instantaneous large current is passed through the electromagnetic forming coil in this state to expand the diameter of the cylindrical material ring. Then, it is pressed against the molding surface of the molding die and electromagnetically molded into a shape corresponding to the molding surface. In the present invention, the bead means a protrusion protruding in the outer diameter direction of the cylindrical ring.

Further, another manufacturing method of the cylindrical ring with beads according to the present invention is such that a bead molding is performed along the circumferential direction of the molding surface with the outer surface side being a molding surface on the inner circumferential side of the closed cylindrical metal ring made of metal. A mold having protrusions formed thereon, an electromagnetic forming coil is arranged on the outer peripheral side of the cylindrical material ring, and in that state, an instantaneous large current is passed through the electromagnetic forming coil, and the cylindrical material The ring is reduced in diameter, pressed against the molding surface of the molding die, and electromagnetically molded into a shape corresponding to the molding surface. In this case, groove portions along the circumferential direction are formed on both sides of the protrusion on the molding surface of the mold as necessary.
Both methods are suitable for the production of reinforcing rings for run-flat tires.
Electromagnetic forming itself is a method in which a strong current is instantaneously applied to a coil to create a strong magnetic field, which is formed by the interaction of the eddy current and magnetic field generated in the molded object (conductor) placed in the coil. For example, as disclosed in JP-A-6-31226, JP-A-9-166111, JP-A-58-4601, etc. The instantaneous large current is, for example, a current value at a level of 10 kA or more.

In both the above manufacturing methods, it is desirable that the molding surface of the mold is plane symmetric with respect to a plane perpendicular to the axial direction at a central position in the axial direction. Furthermore, it is desirable to match the axial center position of the cylindrical material ring with the axial center position of the molding surface of the mold. When a cylindrical material ring is formed by expanding or reducing the diameter by electromagnetic forming, the axial length is shortened (because the material is drawn into the groove of the forming surface), but the forming surface should be as described above. This is because the possibility of more uniform shortening and molding of the cylindrical material ring is increased. The axial direction of the mold forming surface and the axial direction of the cylindrical material ring are matched.
Further, when the diameter is increased, the inner diameter at the axial center position of the molding surface of the mold is set to be the smallest, and the outer peripheral surface of the cylindrical material ring and the molding surface of the mold are in contact with each other at that location. When set, the cylindrical material ring has a shape positioned at the location at the time of molding, and more uniform molding is realized. Conversely, when the diameter is reduced, the outer diameter at the axial center position of the molding surface of the mold is set to the largest, and the inner peripheral surface of the cylindrical material ring and the molding surface of the mold are in contact with each other at that location. It should be set as follows. In any case, it is desirable to match the axial center position of the molding surface of the mold with the axial center position of the cylindrical material ring.

  In the manufacturing method, the material of the cylindrical material ring is preferably copper, copper alloy, aluminum, or aluminum alloy having good conductivity. In addition, as for the quality of the material, the annealed material (O material specified in JISH0001 if aluminum or aluminum alloy) has good electrical conductivity, and the hot-heated material (also specified in JISH0001). F material) is desirable because it has good conductivity and can be supplied at low cost. Aluminum alloys generally have good electrical conductivity and relatively high specific strength, and JIS 6000 series aluminum alloys, particularly 6063 and 6061, are particularly desirable. If it is 5000 series, 5052 etc. are especially desirable.

In the manufacturing method, as the cylindrical material ring to be subjected to electromagnetic forming, a rolled plate material or an extruded plate material is bent into a ring shape, the ends are joined, or extruded into a cylindrical cross section, which is a predetermined length. What was cut into (length in the direction of the extrusion axis) can be used.
In the case of an extruded plate material, the thickness of the cross section can be set arbitrarily, so that the portion that becomes thinner when expanded or reduced in diameter by electromagnetic forming (if expanded, the location where the bead is formed and its vicinity, When the diameter is set, the thickness of the cylindrical ring with the bead after electromagnetic forming can be made uniform by previously setting the thickness of the groove portions on both sides of the bead and the vicinity thereof in advance.

Further, a rolled plate material or an extruded plate material can be used as a cylindrical material ring by spirally winding a spiral tube in the manner of manufacturing a spiral tube and joining the joints. In this case, a long spiral tube may be manufactured and cut into a necessary length as a cylindrical material ring.
When forming a cylindrical ring by welding, lap welding inevitably creates a minute gap in the overlapping part of the plates, and there is a risk that sparks will occur at the time of electromagnetic forming, preventing normal electromagnetic forming. Butt welding is desirable.
Various methods such as resistance welding, MIG welding, laser welding, and FSW (friction stir welding) can be used as the welding method, and various shapes can be used as the groove shape of the butt joint. In particular, it is not desirable that the thickness of the joint is reduced after joining. Conversely, if there are too many surpluses, it is necessary to remove them. For this reason, laser welding with less surplus is suitable.

As the cylindrical material ring, a ring in which a large number of holes are formed can be used. It is desirable that the holes are regularly arranged on the peripheral wall. By forming a large number of holes in the peripheral wall, the weight of the cylindrical ring with beads can be reduced. A cylindrical material ring in which holes are regularly formed on almost the entire surface of the peripheral wall is highly effective in reducing the weight. As this type of cylindrical material ring, for example, a punching metal bent into a ring shape and joined at the ends, or a spirally wound seam welded.
Moreover, the hole formed in the cylindrical material ring can be used for connection with other members in the cylindrical ring with beads after molding. For example, in the case of a reinforcement ring of a run-flat tire, resin is attached to both ends of the reinforcement ring in the axial direction (see Patent Document 1). At this time, resin enters the hole, and the connection between the reinforcement ring and the resin is more Surely done.

  At the time of electromagnetic forming, the material of the cylindrical material ring is pushed into the groove of the molding surface of the mold, and accordingly, the material of the cylindrical material ring moves in the axial direction along the molding surface of the mold. A strong frictional resistance is generated between the molding surface of the steel and the cylindrical material ring. By forming a large number of holes in the cylindrical material ring, the contact area between the mold and the cylindrical material ring that are in contact with each other during electromagnetic forming is reduced, and the frictional resistance between them is reduced. The flow of the material into the groove portion can be made smoother and more accurate molding can be performed. In particular, it is effective to form a large number of holes along the circumferential direction in a portion of the peripheral wall of the cylindrical material ring that flows into the groove portion from outside the groove portion of the molding surface of the mold during electromagnetic forming. This location is generally the axial ends of the cylindrical material ring.

The hole formed in the cylindrical material ring can also be used as a positioning hole during electromagnetic forming. When forming a cylindrical ring with a bead by expanding the diameter by electromagnetic forming, a large number of protrusions are formed along the circumferential direction at a portion having the smallest inner diameter on the molding surface of the mold, and the protrusion is formed on the cylindrical material ring. A number of holes are formed along the circumferential direction at corresponding locations, and when the mold is disposed on the outer peripheral side of the cylindrical material ring, the protrusions are fitted into the holes. In this case, the protrusion is formed at the axial center position of the molding surface of the mold, and is formed between the adjacent groove portions of the molding surface, and the hole is the axial center position of the cylindrical material ring. It is desirable to be formed.
When forming a cylindrical ring with a bead by reducing the diameter by electromagnetic forming, a large number of protrusions are formed along the circumferential direction at a portion having the largest outer diameter on the molding surface of the mold, and the protrusion is formed on the cylindrical ring. A number of holes are formed along the circumferential direction at corresponding locations, and when the mold is disposed on the inner peripheral side of the cylindrical ring, the protrusion is fitted into the hole. In this case, the protrusion is formed at the center position in the axial direction of the molding surface of the mold and is formed in the protrusion on the molding surface, and the hole is formed at the center position in the axial direction of the cylindrical material ring. Is desirable.
As a result, the cylindrical material ring is accurately positioned in the mold, and the axial movement of the material of the cylindrical material ring does not occur at the position of the positioning hole even during electromagnetic forming.

  As an electromagnetic molding die for carrying out the manufacturing method, an electromagnetic molding die in which the inner surface side is a ring-shaped molding surface and a groove portion for bead molding is formed along the circumferential direction of the molding surface, or The outer surface side is a ring-shaped molding surface, and bead-forming ridges are formed along the circumferential direction of the molding surface (further grooves are formed on both sides of the ridges if necessary). A mold is used. Since electromagnetic forming is completed in a very short time of around several hundreds of microseconds, there is no time for air to escape in the gap between the mold and the cylindrical material ring during molding, and in particular, the mold and the material pressed against it in the groove There is a problem that the pressure is increased by being confined between the two and the high pressure air prevents the material from being pressed against the molding surface in the groove portion, and a dent is formed on the surface of the bead after electromagnetic molding. Therefore, it is desirable to form a hole or a slit for air bleeding in the groove.

  A more preferable mold structure is an electromagnetic mold in which the inner surface side is a ring-shaped molding surface and a bead molding groove is formed along the circumferential direction of the molding surface, and the groove is divided in the axial direction. The divided molds are arranged with a gap in the axial direction. In the case of an electromagnetic molding die in which the outer surface side is a ring-shaped molding surface, and a bead-forming ridge and grooves are formed on both sides along the circumferential direction of the molding surface, the groove is divided in the axial direction. The divided molds are arranged with a gap in the axial direction. As a result, the mold is formed with slits in the groove part over the entire circumference, and the problem of the dent is completely eliminated. In addition, it cannot be overemphasized that an axial direction means the axial direction of the molding surface (and cylindrical raw material ring) of a metal mold | die.

  When the hole formed in the cylindrical material ring is used as a positioning hole for electromagnetic forming, the electromagnetic forming mold has a ring-shaped forming surface on the inner surface side when the electromagnetic forming is expanded, A groove portion for bead molding is formed along the circumferential direction, and a number of positioning projections are formed along the circumferential direction at a portion having the smallest inner diameter on the molding surface. On the other hand, when the electromagnetic forming has a reduced diameter, the outer surface side is a ring-shaped forming surface, and a bead forming protrusion is formed along the circumferential direction of the forming surface, and the outer diameter of the forming surface is the largest. A large number of positioning projections are formed in the circumferential direction.

  A cylindrical ring with a metal bead having a bead in the circumferential direction can be manufactured by the manufacturing method described above. The cylindrical ring with a bead is desirably plane-symmetric with respect to a plane perpendicular to the axial direction at a central position in the axial direction as a plane of symmetry, and one or a plurality of beads can be formed as necessary. . In addition, a typical cylindrical ring with a bead can be recognized as a substantially rotating body (one having a hole in the side wall is not a rotating body in the strict sense, but the cylindrical ring has If you look at the outline, it can be regarded as a rotating body). However, a shape slightly deviated from the rotating body is included in the present invention as long as the overall shape can be recognized as a cylindrical ring with a bead.

Electromagnetic forming has the characteristic that a workpiece is repeatedly loaded in a very short time, so it has excellent shape freezing (less springback), can form a cylindrical ring with a bead with high precision, It is easy to get the degree precisely. In particular, when forming by radially expanding the diameter, higher roundness can be realized than when forming by reducing the diameter. In addition, since electromagnetic forming has the above characteristics, work hardening is greater than that of conventional processing methods, and the bead (particularly the top of the bead) is strengthened by work hardening. On the other hand, the run-flat tire reinforcement ring requires high roundness and the tread surface (the part that contacts the tire via the tire) becomes the top of the bead, so the roundness is high and the bead is reinforced (that is, by expanding the diameter). Electromagnetically formed) beaded cylindrical rings are particularly suitable as the reinforcing ring. Note that aluminum or an aluminum alloy having a plate thickness of 3 mm or less is used as a reinforcing ring of the run-flat tire.
The cylindrical ring with beads does not have a joint when a cylindrical extruded material is used, but usually has at least one joint, preferably a joint by butt welding. This joint is formed parallel or oblique to the axial direction.

  In addition, after forming a cylindrical ring with a bead by electromagnetic forming (expanding diameter, reducing diameter), if the dimensional accuracy is insufficient, the cylindrical ring with bead is subjected to a correction process such as roll correction to bead Thus, the dimensional accuracy of each part can be improved. Further, the dimensional accuracy can be improved by repeating the electromagnetic forming a plurality of times. In this case, after performing electromagnetic forming (expansion), perform electromagnetic forming (reduced diameter), or in reverse order, or repeatedly perform the same type of electromagnetic forming of expanded or reduced diameter multiple times. Is also possible. In any case, the second and subsequent electromagnetic forming has the meaning of correction.

In addition, in electromagnetic forming (expanding diameter, reducing diameter), a plurality of cylindrical rings with beads can be taken (forming a plurality of cylindrical rings with beads at one time). In this case, the mold needs to have a plurality of sets of forming surfaces corresponding to the cylindrical ring with beads in the axial direction, and the coil body for electromagnetic forming must also have a corresponding axial length. In this case, by arranging a circular cutting blade between the molding surfaces corresponding to the cylindrical rings with beads of the mold, it is possible to separate the cylindrical rings with beads at the same time as electromagnetic forming.
When taking multiple pieces, if the cylindrical ring with beads is not separated in the electromagnetic molding die, use a roll with a cutting blade and separate into each cylindrical ring with beads at the same time as roll correction in the manner of roll correction. You can also

  Furthermore, the beaded cylindrical ring formed by electromagnetic forming can be cut and separated in the circumferential direction as necessary. The cutting direction is preferably parallel to the axial direction of the cylindrical ring with beads or oblique to the axial direction, for example. Since this cylindrical ring with a bead can fit two through the cut | disconnected location (cut | interruption), there exists an advantage in which an occupation space becomes small in the case of storage and conveyance. Moreover, this cylindrical ring with a bead can be made into the ring closed again by joining the cut | disconnected location as needed. When joining by welding, butt welding is desirable, and laser welding with less surplus is particularly suitable.

  According to the present invention, a cylindrical ring with a bead having high accuracy by electromagnetic forming can be manufactured at low cost and with high productivity. Moreover, the cylindrical ring with a bead formed by expanding the diameter has excellent characteristics particularly for a reinforcing ring of a run-flat tire.

Hereinafter, with reference to FIGS. 1-25, the manufacturing method of the cylindrical ring with a bead concerning this invention and the cylindrical ring with a bead manufactured by it are demonstrated concretely.
A cylindrical material ring 1 shown in FIG. 1 is formed, for example, by bending an aluminum alloy plate and butt-welding the ends. Reference numeral 2 denotes a joint portion by butt joint.
FIG. 3 shows a method of electromagnetic forming (expanding diameter) the cylindrical material ring 1. In FIG. 3A, the inner surface side is a molding surface on the outer peripheral side of the cylindrical material ring 1, and the molding surface. A mold 6 having bead forming grooves 3 to 5 formed along the circumferential direction is disposed, and an electromagnetic forming coil body 7 is disposed on the inner peripheral side of the cylindrical material ring 1. The molding surface of the mold 6 is substantially a rotating surface (in a strict sense, it is not a rotating surface because there are holes 11 to be described later, but as a function of the molding surface, The plane is substantially plane symmetric with respect to a plane perpendicular to the axial direction at the center position in the axial direction. Further, the axial center position of the molding surface of the mold 6 and the axial center position of the cylindrical material ring 1 are matched. A slight gap is formed between the outer peripheral surface of the cylindrical material ring 1 and the inner peripheral surface of the mold 6 and between the inner peripheral surface of the cylindrical material ring 1 and the coil body 7 for electromagnetic forming.

The mold 6 is preferably made of a metal having low conductivity, such as stainless steel. Materials other than metals, for example, non-conductive structural materials such as fiber reinforced plastics and bakelites can also be used. The groove portions 3 to 5 formed on the molding surface of the mold 6 are connected to each other in a wavy shape with the opening directed radially inward, and the ends of the groove portions 3 and 5 are connected to end parallel portions 8 and 9 of the molding surface, respectively. ing. A large number of air vent holes 11 are formed along the circumferential direction at the bottom of each of the grooves 3 to 5. The hole 11 may be a slit formed long in the circumferential direction. The electromagnetic forming coil body 7 is formed by embedding a forming coil 7a in an electrical insulator.
When an instantaneous large current is passed through the coil body 7 for electromagnetic forming in the state of FIG. 3A, a magnetic repulsive force is generated in the cylindrical material ring 1, and the cylindrical material ring 1 instantaneously expands in diameter and the mold 6 As shown in FIG. 3 (b), it is molded into a shape along the molding surface, and has short parallel portions 12 and 13 at both ends in the axial direction and a circumference that bulges radially outward between them. It becomes a cylindrical ring 17 with beads consisting of three beads 14 to 16 in the direction (each bead 14 to 16 is connected to the waveform) (see FIG. 2 for the detailed shape). The beaded cylindrical ring 17 is a substantial rotating body, and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position. With the electromagnetic forming, the material of the cylindrical material ring 1 is drawn into the grooves 3 to 5, and as a result, the axial width of the cylindrical ring 17 with beads is smaller than the axial width of the cylindrical material ring 1. Yes.
After the molding, the mold 6 is divided into a plurality of divided pieces (divided pieces 25a constituting the divided mold 25 in FIG. 4) divided in the circumferential direction so that the cylindrical ring 17 with beads can be taken out from the mold 6. , 25b).

FIG. 4 is an example of a mold structure composed of a plurality of divided molds divided in the axial direction. The mold 21 has a molding surface on the inner surface side, and is formed with groove portions 22 to 24 for bead molding along the circumferential direction of the molding surface, and a plurality of pieces divided in the axial direction in the groove portions 22 to 24. Ring-shaped split molds 25 to 28, and each of the split molds 25 to 28 is arranged via ring-shaped spacers 29 to 31. As a result, a gap 32 is provided between the adjacent split molds 25 to 28. -34 are formed.
Further, the split mold 25 (same as the split molds 26 to 28) is composed of a plurality of split pieces 25a and 25b (in some cases, two or more split pieces) divided in the circumferential direction. These are connected by a bolt 35 and a locking piece 36 to constitute a split mold 25.
In FIG. 4, 37 is a bolt for fixing the divided molds 25 to 28, and 38 is a nut.

  In this mold 21, each of the divided molds 25 to 28 is formed with a curved molding surface that constitutes a part of each of the groove portions 22 to 24, and the molding surface is located at the central portion (the bottom portion of the groove portions 22 to 24). The grooves 22 to 24 are configured together with the gaps 32 to 34 to be performed. That is, the groove portion 22 is composed of a curved molding surface and a central gap 32 between the adjacent divided molds 25 and 26, and the groove portion 23 is a gap 33 between the curved molding surface and the central portion of the adjacent divided molds 26 and 27. The groove portion 24 includes a curved molding surface of the adjacent divided molds 27 and 28 and a gap 34 at the center portion. The molding surface of the mold 21 is substantially a rotational surface, and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position. The gaps 32 to 34 exist over the entire circumference of each of the groove portions 22 to 24, and function as air vent slits during electromagnetic forming.

  The cylindrical material ring is arranged on the inner surface side of the mold 21 so that the axial center position of the molding surface of the mold 21 coincides with the axial center position of the cylindrical material ring. When the electromagnetic forming coil body is arranged on the base plate and electromagnetic forming is performed, the cylindrical material ring is instantly expanded in diameter as described with reference to FIGS. In the gaps 32 to 34 (bottom portions of the groove portions 22 to 24), the cylindrical material ring is pressed according to the load applied. Freely deform. That is, the top part of the bead of the cylindrical ring with beads is formed in the gaps 32 to 34 (bottom parts of the groove parts 22 to 24). By appropriately setting the widths of the gaps 32 to 34, air can be removed without any trouble, and in the gaps 32 to 34, the molding surfaces of the adjacent divided molds are sandwiched by sandwiching the gaps 32 to 34. It can be deformed into a shape substantially along the curve (see the phantom line E in FIG. 4C). The obtained cylindrical ring with a bead is substantially a rotating body, and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position.

  FIG. 5 shows a method of electromagnetic forming (reducing the diameter) of the cylindrical material ring 1. In FIG. 5A, the outer surface side is a molding surface on the inner peripheral side of the cylindrical material ring 1, and the molding surface. The bead-forming ridges 41 and 42 are formed along the circumferential direction, and a mold 44 having grooves 43a to 43c formed on both sides thereof is disposed. On the outer peripheral side of the cylindrical material ring 1, electromagnetic forming is performed. A coil body 45 is disposed. A slight gap is formed between the inner peripheral surface of the cylindrical material ring 1 and the outer peripheral surface of the mold 44 and between the outer peripheral surface of the cylindrical material ring 1 and the coil body 45 for electromagnetic forming.

  The ridges 41 and 42 formed on the molding surface of the mold 44 are directed outward in the radial direction, the grooves 43a to 43c are directed outward in the radial direction, and the ridges 41 and 42 and the grooves 43a to 43c are The end portions of the grooves 43a and 43c are connected to the end parallel portions 46 and 47 of the molding surface, respectively. The molding surface of the mold 44 is substantially a plane of rotation, and is substantially plane symmetric with respect to a plane perpendicular to the axial direction at the axial center position. Further, the axial center position of the molding surface of the mold 44 is matched with the axial center position of the cylindrical material ring 1. In addition, air vent holes or slits 48 are formed at the bottom of each of the grooves 43a to 43c, as in FIG.

When an instantaneous large current is passed through the electromagnetic forming coil body 45 in the state of FIG. 5A, a magnetic repulsive force is generated in the cylindrical material ring 1, and the cylindrical material ring 1 is instantaneously reduced in diameter and the mold 44. As shown in FIG. 5 (b), it is molded into a shape along the molding surface, short parallel portions 51 and 52 at the end portions, and a circumferential direction projecting radially outward therebetween. A beaded cylindrical ring 56 is formed of two beads 53 and 54 (grooves 55a to 55c are formed on both sides thereof and connected to the beads 53 and 54 in a waveform). The beaded cylindrical ring 56 is substantially a rotating body, and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position. With the electromagnetic forming, the material of the cylindrical material ring 1 is drawn into the grooves 43a to 43c, and as a result, the axial width of the cylindrical ring 56 with beads is smaller than the axial width of the cylindrical material ring 1. Yes.
The mold 44 is composed of a plurality of divided pieces divided in the circumferential direction so that the cylindrical ring 54 with beads can be removed from the mold 44 after molding.

FIG. 6 shows a roll correction method for improving the dimensional accuracy of the cylindrical ring 57 with a bead after electromagnetic forming (expanding diameter, reducing diameter). For example, it may be performed when the air is not sufficiently vented and the bead is depressed, or when the accuracy of the top of the free-deformed bead is inferior by electromagnetic forming using a mold of the type shown in FIG.
A cylindrical ring 57 with a bead is sandwiched between an inner roll 58 and outer rolls 59 and 59 whose outer shapes are finished to the required accuracy, the amount of pushing of the inner roll 58 is adjusted, and each roll is rotated to roll. Correct.

  FIG. 7 shows a correction method for further performing electromagnetic forming (reducing diameter) in order to improve the dimensional accuracy of the cylindrical ring 61 with beads after electromagnetic forming (expanding diameter). It may be performed when the air is not sufficiently vented and a dent is generated in the bead, or when the accuracy of the top part of the bead which is freely deformed by electromagnetic forming using a mold of the type shown in FIG. 4 is inferior. In this case, the beaded cylindrical ring 61 is formed in a slightly larger diameter than the final shape.

As shown in FIG. 7 (a), on the inner peripheral side of the beaded cylindrical ring 61 that has been electromagnetically molded (expanded in diameter) in advance, the outer surface is the molding surface corresponding to the final shape, and the circumferential direction of the molding surface A metal mold 65 having corrective protrusions 62 to 64 formed thereon is disposed, and an electromagnetic forming coil body 66 is disposed on the outer peripheral side of the cylindrical ring 61 with beads. The molding surface of the mold 65 is substantially a rotating surface. 67 is a hole or slit for air bleeding. Moreover, the metal mold | die 65 consists of the some division | segmentation piece divided | segmented into the circumferential direction similarly to the conventional metal mold | die.
In this state, when an instantaneous large current is passed through the electromagnetic forming coil 66, as shown in FIG. 7B, electromagnetic forming (diameter reduction) is performed in the same manner as described with reference to FIG. 61 is formed into a shape along the molding surface of the mold 65, that is, corrected, and becomes a cylindrical ring 69 with a bead having high dimensional accuracy.

FIG. 8 shows an attempt to obtain a beaded cylindrical ring with high dimensional accuracy by repeating electromagnetic forming.
First, as shown in FIG. 8 (a), on the outer peripheral side of the cylindrical material ring 1, the inner surface side is formed as a molding surface, and groove portions 71 to 73 for bead molding are formed along the circumferential direction of the molding surface. A mold 74 is disposed, and an electromagnetic forming coil body 75 is disposed on the inner peripheral side of the cylindrical material ring 1. The molding surface of the mold 74 substantially forms a rotating surface. A large number of holes or slits 76 for air bleeding are formed in the bottom of each of the grooves 71 to 73 along the circumferential direction. The mold 74 is composed of a plurality of divided pieces divided in the circumferential direction.

  When an instantaneous large current is passed through the electromagnetic forming coil body 75 in the state of FIG. 8A, the cylindrical material ring 1 is instantaneously expanded in diameter and pressed against the forming surface of the mold 74. However, the electric energy applied to the coil body 75 for electromagnetic forming at this time, that is, the magnetic repulsive force generated in the cylindrical material ring 1 is formed by forming the cylindrical ring 1 into the mold 74 as shown in FIG. It is set not to be so large as to be formed into a shape sufficiently along the surface (particularly the grooves 71 to 73). That is, the cylindrical material ring 1 is drawn into the grooves 71 to 73 and swells, but there is a gap between the molded cylindrical ring 77 with beads and the molding surface (particularly the grooves 71 to 73) of the die 74. Has been actively left. Therefore, even if air bleeding is insufficient and air is trapped in the gap, the problem of dents is reduced because the air pressure is not extremely high.

Subsequently, as shown in FIG. 8C, electromagnetic forming is performed once again, and this time the beaded cylindrical ring 77 is formed into a shape along the forming surface (particularly the grooves 71 to 73) of the die 74, that is, the final shape. Mold. This molding can also be called a kind of correction.
In this example, a magnetic repulsive force is generated more efficiently using the electromagnetic forming coil body 78 having a large coil diameter. The formed cylindrical ring 79 with beads is shaped along the molding surface of the mold 74 and both are in close contact with each other, but from the state of the cylindrical material ring 1, the cylindrical ring 79 with beads is formed at once. Compared to the case, since the amount of air that may be trapped in the grooves 71 to 73 is small, even if air bleeding is insufficient, the pressure does not increase so much and the problem of dents is solved.
In this example, two-stage molding is performed using the same mold 74, but different molds (pre-molding mold and finishing mold) may be used. In that case, you may shape | mold in the shape along the shaping | molding surface of a preforming metal mold | die by the 1st shaping | molding.

FIG. 9 shows a method of forming a plurality (two in this example) of cylindrical rings with beads at a time. On the outer peripheral side of the cylindrical material ring 81 of two lengths, a mold 82 whose inner surface side is a molding surface is disposed, and on the inner peripheral side of the cylindrical material ring 81, an electromagnetic forming coil body 83 is disposed. ing. On the molding surface of the mold 82, groove portions 84 to 86 for bead forming are formed along the circumferential direction, and two sets of the groove portions 84 to 86 are formed side by side in the axial direction. A circular cutting blade 87 is formed inwardly. A large number of holes or slits 88 for releasing air are formed along the circumferential direction at the bottom of each of the grooves 84 to 86. The mold 82 includes a plurality of divided pieces divided in the circumferential direction.
When an instantaneous large current is passed through the electromagnetic forming coil body 83 in the state of FIG. 9, a magnetic repulsive force is generated in the cylindrical material ring 81, and the cylindrical material ring 1 instantaneously expands in diameter to form the molding surface of the mold 82. And is formed into a shape along the forming surface, and at the same time, separated at an intermediate position by a cutting blade. Thereby, two same thing as the cylindrical ring 17 with a bead shown in FIG.3 (b) can be shape | molded simultaneously.

When the cutting blade 87 is not provided in the mold 82 shown in FIG. 9, a cylindrical ring with a bead in which a plurality of cylindrical rings with a bead are connected is formed.
FIG. 10 shows a roll straightening and cutting method for improving the dimensional accuracy of a cylindrical ring 91 with a bead in which a plurality (two) of cylindrical rings with a bead are connected in this way and separating them into a plurality (two) at the same time. Is shown. The roll correction is basically the same idea as the method of FIG. 6, but in this case, a circular cutting blade 93 is formed at an intermediate position of the inner roll 92, and the receiving edge of the cutting blade 93 is received at a corresponding portion of the outer rolls 94, 94. A blade 95 is formed. A cylindrical ring 91 with a bead is sandwiched between the inner roll 93 and the outer rolls 94, 94, and each roll is rotated and the inner roll 93 is pushed in to perform roll correction and cutting.

FIG. 11 shows a cylindrical material ring 101, in which a large number of holes 102 are formed on the entire peripheral wall. The cylindrical material ring 101 is a rectangular metal plate (for example, an aluminum alloy plate) in which holes 102 are regularly formed in a grid pattern, that is, a punching metal is bent into a cylindrical shape, and ends are joined by welding or the like. Can be obtained.
When the cylindrical material ring 101 is electromagnetically formed using, for example, the mold 6 and the electromagnetic forming coil 7 shown in FIG. 3, a lighter cylindrical ring with a bead can be formed. In addition, since a large number of holes 102 are formed on the entire surface of the peripheral wall of the cylindrical material ring 101, air vent holes and slits formed in the mold 6 and the like, and the mold 21 (see FIG. 4) are formed. There is no need for a vented air gap.

  FIG. 12 shows a cylindrical material ring 103, in which a large number of holes 102 are formed symmetrically on the peripheral walls at both ends in the axial direction along the circumferential direction. These holes 102 constitute two hole rows (the outer row is 102a and the inner row is 102b) that make a round on the peripheral wall at each end in the axial direction, and each hole 102 is equal in each of the hole rows 102a and 102b. Arranged at intervals. This cylindrical material ring 103 is formed by winding a rectangular metal plate (for example, an aluminum alloy plate) in which a large number of holes 102 are formed in two rows in the vicinity of each long side edge in parallel with the long side. The end can be obtained by welding or the like.

  An electromagnetic forming method using the cylindrical material ring 103 is shown in FIG. In FIG. 13 (a), a mold 106 (metal mold) in which the inner surface side is a molding surface on the outer circumferential side of a cylindrical material ring 103, and grooves 104, 105 for bead molding are formed along the circumferential direction of the molding surface. As in the mold 6, a plurality of divided pieces divided in the circumferential direction are disposed, and an electromagnetic forming coil body 107 is disposed on the inner peripheral side of the cylindrical material ring 103. The molding surface of the mold 106 is substantially a rotational surface and is substantially plane symmetric with respect to a plane perpendicular to the axial direction at the axial center position. Further, the axial center position of the molding surface of the mold 106 is matched with the axial center position of the cylindrical material ring 103.

  When an instantaneous large current is passed through the electromagnetic forming coil body 107 in the state of FIG. 13A, a magnetic repulsive force is generated in the cylindrical material ring 103, and the cylindrical material ring 103 is instantaneously expanded in diameter and the mold 106. As shown in FIG. 13 (b), it is molded into a shape along the molding surface, short parallel portions 108 and 109 at both ends in the axial direction, and a circumference that bulges radially outward between them. This is a cylindrical ring 113 with beads composed of two beads 111 and 112 in the direction (both beads 111 and 112 are connected in a waveform). The beaded cylindrical ring 113 is substantially a rotating body (there is a hole 102 and the like, and it cannot be said that it is a rotating body in a strict sense. It can be regarded as a rotating body) and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position.

Along with the electromagnetic forming, the material of the cylindrical material ring 103 is pushed into the groove portions 104 and 105, and as a result, the material of the end portion of the cylindrical material ring 103 located axially outside the groove portions 104 and 105 is removed. , Flows into the grooves 104 and 105. Before molding, the hole 102 of the cylindrical material ring 103 was positioned outside the grooves 104 and 105 on the molding surface of the mold 106 in both hole rows (hole rows 102a and 102b). The hole row 102b is positioned in the groove portions 104 and 105 as the material at the end of the hole flows into the groove portions 104 and 105. That is, in the cylindrical ring 113 with beads, the axially inner hole row 102b is located on the beads 111 and 112, and the axially outer hole row 102a is located near the boundary between the parallel portions 108 and 109 and the beads 111 and 112. is doing.
When the end of the cylindrical material ring 103 flows into the grooves 104 and 105 from the end parallel portion of the mold 106, the portion where the hole 102 is formed compared to the cylindrical ring 1 or the like where no hole is formed. The contact area between the molding surface of the mold 106 and the cylindrical ring 103 is reduced, and the frictional resistance therebetween is reduced. As a result, the flow into the grooves 104 and 105 of the cylindrical ring 103 is smoothed, and the electromagnetic wave is accurately generated. Molding can be performed. This effect can be obtained in the same manner when the cylindrical ring 101 is formed.

FIG. 14 shows a cylindrical material ring 115, in which a large number of holes 102 are formed at equal intervals in the circumferential direction at a central position in the axial direction. The cylindrical ring material 115 can be obtained by winding a rectangular metal plate (for example, an aluminum alloy plate) in which a large number of holes 102 are formed in a row into a cylindrical shape and joining the ends by welding or the like.
An electromagnetic forming method using this cylindrical material ring 115 is shown in FIG. In FIG. 15A, a mold 116 (consisting of a plurality of divided pieces divided in the circumferential direction like the mold 6) arranged on the outer peripheral side of the cylindrical material ring 115 has a molding surface on the inner surface side. The groove portions 117 and 118 for bead molding are formed along the circumferential direction of the molding surface, the intermediate portion 119 of the groove portions 117 and 118 protrudes toward the inner diameter side, and the protrusion is formed at the apex where the inner diameter is the smallest. 121 are formed at equal intervals along the circumferential direction. The molding surface of the mold 116 is substantially a rotational surface (in other words, it is not a rotational surface in the strict sense because there are projections 121 and the like, but it can be regarded as a rotational surface as a function of the molding surface. ), And a plane perpendicular to the axial direction at the axial center position is substantially plane-symmetrical.
When the interval between the adjacent protrusions 121 of the mold 116 and the interval between the adjacent holes 102 of the cylindrical material ring 115 are the same, and the mold 116 is disposed around the cylindrical material ring 115, the intermediate The inner diameter of the apex of the portion 119 is substantially the same as the outer shape of the cylindrical material ring 115, the projection 121 is fitted in the hole 102, and the molding surface of the mold 116 and the outer periphery of the cylindrical material ring 115 at the apex of the intermediate portion 119 The surfaces are touching.

When an instantaneous large current is passed through the electromagnetic forming coil body 122 in the state of FIG. 15A, a magnetic repulsive force is generated in the cylindrical material ring 115, and the cylindrical material ring 115 instantaneously expands in diameter and the mold 116. As shown in FIG. 15 (b), it is shaped into a shape along the molding surface, and has short parallel portions 123 and 124 at both ends in the axial direction and a circumference that bulges radially outward between them. A beaded cylindrical ring 127 consisting of two beads 125, 126 in the direction (both beads 125, 126 are connected in a wave form). The beaded cylindrical ring 127 is substantially a rotating body, and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position.
By fitting the protrusion 121 of the mold 116 into the hole 102 of the cylindrical material ring 115, the cylindrical material ring 115 is accurately positioned in the mold 116, and even at the time of electromagnetic forming, at the central portion of the cylindrical material ring 115. Since the material does not move in the axial direction, molding is performed with high accuracy.

When the diameter of the cylindrical material ring 115 is reduced by electromagnetic molding (the mold is disposed inside the cylindrical ring 115), the protrusion that fits into the hole 102 of the cylindrical material ring 115 is the outer diameter of the molding surface of the mold. Is formed at the place where the is the largest. The protrusion is preferably formed at the center position in the axial direction, similar to the mold 116. In addition, when a mold is disposed inside the cylindrical material ring 115, the outer diameter of the molding surface is made substantially the same as the inner diameter of the cylindrical material ring 115.
Even in the cylindrical material ring 101, the holes 102 formed in the circumferential direction (particularly the hole row in the center or the vicinity thereof) can be used for positioning.

FIG. 16 shows a cylindrical material ring 131, in which a large number of holes 102 are formed at equal intervals in one row along the circumferential direction at both ends in the axial direction. The cylindrical material ring 131 obtained by electromagnetic forming using the mold 106 shown in FIG. 13 is a cylindrical ring 132 with beads (solid line portion) shown in FIG. As shown by phantom lines in FIG. 17A, when the resin 133 is melted and attached to both ends in the axial direction of the cylindrical ring 132 with beads, the resin 133 is inserted into the holes 102 as shown in FIG. The cylindrical ring 132 with beads and the resin 133 are firmly connected.
This effect can be similarly obtained even when the cylindrical rings 101 and 103 are used.

18 (a) and 18 (b) show a cylindrical ring with a bead formed by electromagnetic forming and cut in the circumferential direction. The cutting direction is parallel (a) to the axial direction and oblique (b) to the axial direction. The beaded cylindrical rings 134 and 135 can be fitted together through cut portions (cuts 136 and 137).
The beaded cylindrical rings 134 and 135 can be closed again by joining the cut portions by welding or the like, if necessary. 19 (a) and 19 (b) show cylindrical rings 134 and 135 with beads joined by welding (welded portions 138 and 139).
The beaded cylindrical rings 134 and 135 may be used either in a circumferentially separated state (see FIG. 18) or in a joined state again (see FIG. 19). It may be desirable to cut diagonally. For example, when a cylindrical ring with a bead is used as a reinforcing ring for a run-flat tire, the circumferential length t1 of the cut 137 or the welded portion 139 in the cylindrical ring 135 with a bead obliquely cut is determined as the circumferential width of the ground contact surface. If it is set to be larger than t0, the entire vehicle weight is not applied to the cut 137 or the welded portion 139 having a relatively low strength at a time.

When the cylindrical ring with a bead in which a large number of holes are formed is cut off in the circumferential direction and then joined again, the hole 102 can be used for joining. This will be described using a cylindrical ring 132 with beads as an example.
In FIG. 20, the cylindrical ring 132 with beads is cut in the circumferential direction, and then the end portions are partially overlapped and joined by a rivet 141. The rivet 141 passes through the overlapped hole 102 and joins the ends.
FIG. 21 shows a case where the cylindrical ring 132 with beads is cut off in the circumferential direction, and ends thereof are partially overlapped and joined by a molten resin 142. The resin 142 enters the solidified hole 102 and solidifies, and joins the ends.
In FIG. 22, the cylindrical ring 132 with beads is cut in the circumferential direction, and then the cut 143 is opened, and these are joined by molten resin 144. The resin 144 enters into the hole 102 at the end and solidifies to join the ends. In this case, the cut line 143 may be closed and bonded with the resin 144.

  When a cylindrical ring with a bead formed with a large number of holes is cut off in the circumferential direction, particularly when the cutting line is formed obliquely with respect to the axial direction, the arrangement of the large number of holes 102 is shown in FIG. From the grid-like arrangement (see the cylindrical ring 101 with beads in FIG. 11), the zigzag arrangement shown in FIG. 23B (the positions of the holes 102 in the adjacent hole rows are shifted by a half pitch in the circumferential direction). There are times when it is preferable. As shown in FIGS. 23 (a) and 23 (b), when an oblique hole row constituted by a large number of holes 102 is viewed, the interval between the hole rows is greater than that in the grid arrangement (h1). This is because (h2> h1) can be taken more widely in the staggered arrangement (h2). Thereby, the zigzag arrangement is easier to cut, and when joining again, it is easier to weld.

FIG. 24 shows a method for electromagnetically forming the cylindrical material ring 1 using a mold 156 similar to the mold 106 (consisting of a plurality of divided pieces divided in the circumferential direction as in the mold 6). It is shown. The mold 156 has a molding surface on the inner surface, and groove portions 151 and 152 for bead molding are formed along the circumferential direction of the molding surface. An intermediate portion 153 of both the groove portions 151 and 152 protrudes toward the inner diameter side, and the intermediate portion At 153, the inner diameter of the molding surface is the smallest. The molding surface of the mold 156 is substantially a rotational surface, and is substantially plane-symmetric with a plane perpendicular to the axial direction at the center position in the axial direction of the mold 156 as a symmetry plane.
As shown in FIG. 24A, the cylindrical material ring 1 is disposed inside the mold 106, and the electromagnetic forming coil body 157 is disposed on the inner peripheral side thereof. The outer diameter of the cylindrical material ring 1 and the inner diameter of the intermediate portion 153 of the mold 106 are substantially the same, and the molding surface of the mold 156 and the outer peripheral surface of the cylindrical material ring 1 are in contact with each other at the intermediate portion 153. Further, the axial center position of the molding surface of the mold 156 and the axial center position of the cylindrical material ring 1 are matched.

When an instantaneous large current is passed through the electromagnetic forming coil body 157 in the state shown in FIG. 24A, a magnetic repulsive force is generated in the cylindrical material ring 1, and the cylindrical material ring 1 instantaneously expands in diameter to form a mold 156. 24B, as shown in FIG. 24 (b), it is molded into a shape along the molding surface, short parallel portions 158, 159 at both ends in the axial direction, and a circumference that bulges radially outward between them. This is a cylindrical ring 164 with beads composed of two beads 161 and 162 in the direction (both beads 161 and 162 are connected to each other by a small diameter portion 163). The beaded cylindrical ring 164 is substantially a rotating body, and is substantially plane-symmetric with respect to a plane perpendicular to the axial direction at the axial center position.
In the case of this method, the axial center position of the cylindrical material ring 1 is positioned at the position of the intermediate portion 153 where the inner diameter of the molding surface of the mold 156 is the smallest (the axial center position of the molding surface). Therefore, more uniform molding can be realized.

FIGS. 25A to 25D show a manufacturing method of a cylindrical material ring. The cylindrical material ring 171 shown in FIG. 25A is joined to the cylindrical material ring 1 shown above by butt joining. The difference is that the portion (weld bead) 172 is formed obliquely with respect to the axial direction. Since the joint portion 172 is oblique, the circumferential weight balance of the cylindrical material 171 is improved as compared with the cylindrical material 1 in which the joint portion 2 is formed in parallel to the axial direction.
A cylindrical material ring 173 shown in FIG. 25 (b) is formed by spirally winding a rolled plate material and joining a seam, and a joint (weld bead) 174 makes one round of the cylinder. The cylindrical material ring 173 has a long joint, but has an excellent weight balance in the circumferential direction.
FIG. 25 (c) is a drawing of individual cylindrical shapes obtained by spirally rolling a rolled plate material, joining seams, manufacturing a spiral tube in advance, and cutting this into a predetermined length (the cutting position is indicated by a virtual line). A method for manufacturing the material ring 173 will be described.
FIG. 25 (d) manufactures a spiral tube in which the joints 176 are densely formed, and cuts this to a predetermined length (the cutting position is indicated by phantom lines) to manufacture individual cylindrical material rings 175. How to do. This cylindrical material ring 175 further has a longer joint 176, but has an excellent weight balance in the circumferential direction.

A cylindrical material ring similar to that shown in FIG. 1 was formed from an aluminum alloy plate, and this was electromagnetically formed to produce a cylindrical ring with a bead.
The material aluminum alloy plate is an extruded plate (6061-F material), which is formed into a cylindrical shape by roll bending using three rolls so that the extrusion direction becomes the feed direction of roll bending. The parts were butt welded (the joint was parallel to the center axis direction of the ring). The cylindrical ring had a thickness of 2.2 mm, an inner diameter of 494 mm, and an axial width of 222 mm. Welding is performed by laser welding and MIG welding. Laser welding is performed under the conditions of output 40 kW, speed 3 m / min, wire A5356WY, φ1.2 mm, feed rate 4 m / min, atmosphere Ar 100%, supply rate 25 l / min. Welding was performed under the conditions of current 80A, voltage 18V, wire A5356WY, φ1.2 mm, feed rate 60 cm / min, atmosphere Ar 100%, supply rate 15 l / min.

Subsequently, this cylindrical material ring was subjected to electromagnetic forming (expanding diameter) using the same mold and electromagnetic forming coil body as shown in FIG. Minimum diameter of mold surface (diameter of parallel part at both ends) 504 mm, diameter of coil body for electromagnetic forming 490 mm, length of magnetic field stabilization region (region where almost same magnetic flux density can be obtained) of coil body for electromagnetic forming The cylindrical ring was placed at the center of this magnetic field stabilization region, and the input energy was 45 kJ.
FIG. 2 shows an electromagnetically formed beaded cylindrical ring. Each of the welding methods had an inner diameter of 500 mm, an outer diameter of 570 mm, an end thickness of 2 mm, and an axial width of 192 mm. The bead had no dent and was shaped along the molding surface of the mold.

It is the side view (a) and front view (b) of the cylindrical material ring before electromagnetic forming. It is sectional drawing (a) of the cylindrical ring with a bead after electromagnetic forming, a side view (b), and a front view (c). The manufacturing method of the cylindrical ring with a bead by electromagnetic shaping | molding is demonstrated, and it is sectional drawing (a) before shaping | molding, and sectional drawing (b) after shaping | molding. It is the side view (a) which shows an example of the metal mold | die structure of the metal mold | die for electromagnetic forming, sectional drawing (b), and its one part enlarged view (c). The manufacturing method of the cylindrical ring with a bead by electromagnetic shaping | molding is demonstrated, and it is sectional drawing (a) before shaping | molding, and sectional drawing (b) after shaping | molding. The correction method of the cylindrical ring with a bead is shown, and is side surface sectional drawing (a) and front sectional drawing (b). The correction method of a cylindrical ring with a bead is shown, and is a cross-sectional view before correction (a) and a cross-sectional view after correction (b). It shows a multistage molding method of a cylindrical ring with a bead, and is a sectional view before molding (a), a sectional view after one-stage molding (b), and a sectional view after two-stage molding (c). It is sectional drawing which shows the multiple taking method of the cylindrical ring with a bead. The separation | separation and the correction | amendment method of a cylindrical ring with a bead which connected two or more are shown, and are side sectional drawing (a) and front sectional drawing (b). It is a front view of the other cylindrical material ring used for this invention. It is a front view of the other cylindrical material ring used for this invention. The manufacturing method of the cylindrical ring with a bead using the cylindrical raw material ring is demonstrated, It is sectional drawing (a) before shaping | molding, and sectional drawing (b) after shaping | molding. It is a front view of the other cylindrical material ring used for this invention. The manufacturing method of the cylindrical ring with a bead using the cylindrical raw material ring is demonstrated, It is sectional drawing (a) before shaping | molding, and sectional drawing (b) after shaping | molding. It is a front view of the other cylindrical material ring used for this invention. It is the front view (a) of the cylindrical ring with a bead shape | molded using the cylindrical raw material ring, and sectional drawing (b) explaining the mode after resin bonding. It is a perspective view of the cylindrical ring with a bead cut away in the circumferential direction. It is a perspective view of the cylindrical ring with a bead joined by welding again after cutting. It is the side view (a) of the cylindrical ring with a bead joined again by the rivet after cut | disconnecting, and its AA sectional drawing (b). It is the side view (a) and AA sectional drawing (b) of the cylindrical ring with a bead joined by resin again after cutting. It is the side view (a) and AA sectional drawing (b) of the cylindrical ring with a bead joined by resin again after cutting. It is a schematic diagram explaining the arrangement | positioning of a hole and the space | interval of a hole row | line | column when cut | disconnecting the cylindrical ring with a bead in which many holes were formed in the circumferential direction. The manufacturing method of the cylindrical ring with a bead by electromagnetic shaping | molding is demonstrated, and it is sectional drawing (a) before shaping | molding, and sectional drawing (b) after shaping | molding. It is a figure explaining the manufacturing method of a cylindrical material ring.

Explanation of symbols

1, 81, 101, 103, 115, 131 Cylindrical material ring 2 Joint 3-5, 22-24, 41-43, 71-73, 84-86, 104-105, 117-118, for bead molding Groove 6, 21, 44, 74, 82, 106, 116 Mold
7, 45, 66, 75, 78, 83, 107, 122 Electromagnetic forming coil bodies 14-16, 53-55, 111-112, 125-126 Beads 17, 56, 57, 61, 69, 77, 79, 91, 113, 127, 132, 134, 135, cylindrical ring with bead 25 to 28 Split mold constituting the mold 21
32 to 34 Clearance 62 to 64 Convex part for correction
65 Die for straightening 58, 59, 92, 94 Straightening roll 87, 93 Cutting blade 102 Hole 121 Protrusion

Claims (11)

On the outer peripheral side of the closed metal cylindrical material ring made of metal, a mold in which the inner surface side is a molding surface and a groove portion for bead formation is formed along the circumferential direction of the molding surface is arranged. An electromagnetic forming coil is arranged on the inner peripheral side, and in that state, an instantaneous large current is passed through the electromagnetic forming coil, the diameter of the cylindrical material ring is expanded and pressed against the molding surface of the molding die, and the molding is performed. Electromagnetic forming into a shape corresponding to the surface, and a large number of protrusions are formed at equal intervals along the circumferential direction at the smallest inner diameter portion of the molding surface of the mold. A number of holes are formed at equal intervals along the circumferential direction at corresponding locations, and when the mold is disposed on the outer peripheral side of the cylindrical material ring, the protrusion is fitted into the hole. Manufacturing method of cylindrical ring with bead. The projection is formed at the center position in the axial direction of the molding surface of the mold, and the hole is defined in claim 1, characterized in that it is formed in the center position in the axial direction of the cylindrical material ring Of manufacturing a cylindrical ring with a bead. 3. The method for manufacturing a cylindrical ring with a bead according to claim 2 , wherein the protrusion is formed between adjacent groove portions of the molding surface. Molding surface of the mold, according to claim smallest inner diameter of the center position in the axial direction, wherein the wherein the molding surface of the mold and the outer peripheral surface of the cylindrical material ring is in contact 1-3 The manufacturing method of the cylindrical ring with a bead described in any one of. The bead according to any one of claims 2 to 4 , wherein the molding surface of the mold is substantially plane symmetric with respect to a plane perpendicular to the axial direction at a central position in the axial direction. Manufacturing method of cylindrical ring. Said cylindrical material ring, the rolling plate or extruded sheet material was bent into a ring shape, claim, characterized in that one is obtained by joining the ends is obtained by joining the seam wound helically 1 The manufacturing method of the cylindrical ring with a bead described in any one of -5 . The method of manufacturing a cylindrical ring with a bead according to any one of claims 1 to 6 , wherein the cylindrical ring with a bead is cut and separated in a circumferential direction after the electromagnetic forming. The method for manufacturing a cylindrical ring with beads according to claim 7 , wherein the cut portions are joined again to form a closed cylindrical ring with beads. The method for producing a cylindrical ring with a bead according to any one of claims 1 to 8 , wherein the cylindrical ring with a bead is used for a reinforcing ring of a run flat tire. The inner surface side is a ring-shaped molding surface, a groove for bead molding is formed along the circumferential direction of the molding surface, and a projection for positioning the cylindrical material ring is formed around the smallest inner diameter of the molding surface. A cylindrical ring with a bead , wherein a plurality of positioning protrusions are formed at equal intervals along a direction, and the positioning protrusions are fitted into holes of the cylindrical material ring formed corresponding to the protrusions. Mold for electromagnetic molding. 11. The electromagnetic forming of a cylindrical ring with a bead according to claim 10 , wherein the molding surface of the mold is substantially plane symmetric with respect to a plane perpendicular to the axial direction at a central position in the axial direction. Mold.

Images