JP3429658B2 - Method for forming constriction in cylindrical member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a constriction in a cylindrical member constituting an anode container or the like of a sodium-sulfur battery.

[0002]

2. Description of the Related Art A cylindrical member provided with a constriction that expands and contracts in the axial direction on the peripheral surface is used in a wide range of fields as a component of an anode container of a sodium-sulfur battery, a bellows, and the like.

When a cylindrical member having such a constriction is used in, for example, a sodium-sulfur battery, the cylindrical member absorbs a load applied to an anode container of the sodium-sulfur battery and breaks the sodium-sulfur battery. It works to prevent

That is, the configuration of a sodium-sulfur battery is as follows:
In general, as shown in FIG. 8, a bottomed cylindrical anode container 6 containing an anode conductive material 11 such as carbon felt impregnated with sulfur as an anode active material, a sodium container 12, and sodium ions are stored. And a bottomed cylindrical solid electrolyte tube (beta-alumina tube) 2 having a function of selectively transmitting light. The anode container 6 has a cylindrical member 13.
And an anode container lid 8. The solid electrolyte tube 2 is joined to the upper end of the cylindrical member 13 via a cylindrical metal fitting 7 having an insulator ring 1 made of, for example, alpha alumina, a ring-shaped bottom 18 and a flange 19.

[0005] The joining state will be described in more detail.
As shown in FIG. 9A, the insulator ring 1 is inserted into a cylinder of the cylindrical metal fitting 7 having a ring-shaped bottom portion 18 and a flange 19, and is thermally and pressure-bonded at a bottom portion by a bonding material 14, and the inside of the ring. The peripheral surface is joined to the upper end of the solid electrolyte tube 2 by the joining glass 15, and the lower surface of the flange 19 of the cylindrical metal fitting 7 and the upper end of the anode container 6 are welded.

[0006] In the sodium-sulfur battery 17 having the above-described configuration, during discharge, the sodium 12 emits electrons to become sodium ions, which are converted into sodium ions.
It passes through the inside and moves to the anode side, reacts with the sulfur in the anode conductive material 11 and the electrons passed through the external circuit to generate sodium polysulfide, and generates a voltage of about 2V. On the other hand, at the time of charging, a reaction of producing sodium and sulfur occurs in reverse to the discharging.

Such a sodium-sulfur battery 17
There is a temperature difference between when the battery is operating and when the battery is stopped, and when the temperature drops when the battery is stopped, sodium polysulfide or sulfur solidifies, and the solid electrolyte tube 2 and the anode container 6 are mutually restrained. When the temperature of the battery is lowered, both the solid electrolyte tube 2 and the anode container 6 thermally contract, but the metal anode container 6
The thermal contraction of the anode container 6 is large, and the contraction of the anode container 6 is suppressed by the solid electrolyte tube 2 having a small thermal contraction.
A downward load acts on the joint 4 between the insulator ring 1 and the cylindrical metal fitting 7, which connects the anode ring and the anode container 6 (FIG. 9).
(A)) arrow direction). Further, a load is also applied to the joint 3 between the insulator ring 1 and the solid electrolyte tube 2, the weld 5 between the cylindrical fitting 7 and the anode container 6, and the weld 9 between the cylindrical member 13 and the anode container lid 8. In some cases, these joints were broken. Further, the insulator ring 1 itself may be destroyed, or the cylindrical metal fitting 7 may be bent by a load.
As shown in FIG. 9B, since the heat shrinkage of the anode container 6 is larger than the heat shrinkage of the solid electrolyte tube 2, the sulfur or sodium polysulfide 20 at the tube bottom of the solid electrolyte tube 2 and in the vicinity of the tube bottom can be used.
Was pressed against the bottom of the solid electrolyte tube 2 and the bottom of the solid electrolyte tube 2 was sometimes damaged.

Therefore, conventionally, in order to prevent the above-mentioned breakage caused by solidification of sodium polysulfide or sulfur and a difference in heat shrinkage between the solid electrolyte tube 2 and the anode container 6, the anode container 6
A part of the peripheral surface is formed with a constriction 10 in the direction of the inner peripheral surface that expands and contracts in the axial direction to provide a spring effect and reduce the load.

Conventionally, for forming such a constriction, for example, as shown in FIG. 7, a cylindrical member 34 constituting an anode container is provided with a concave portion 31 having a shape complementary to the constriction 10 to be formed. Inserting the metal core 30 and rotating the cylindrical member 34, the outer peripheral surface of the cylindrical member 34 is
This was done by pressing at 6.

[0010]

However, in the above-described method, since the thickness of the constricted portion, particularly the tip portion of the constricted portion is smaller than that of the other portion of the cylindrical member, distortion is concentrated. corrosion resistance is deteriorated, with inability to have a sufficient spring effect, there is a repeated problem that poor durability due to the stretching.

On the other hand, if the entire constricted portion is simply made thicker, the compressive and tensile strength of the constricted portion becomes too large, so that when used as an anode container, the generated stress can be sufficiently absorbed. The anode container and the solid electrolyte tube may be damaged.

[0012] The present invention has been made in view of such circumstances, it is an object of the cylindrical member, has a sufficient spring effect, durability, meat excellent in corrosion resistance An object of the present invention is to provide a method for forming a thick neck.

[0013]

Means for Solving the Problems According to the present invention, a core metal having a concave portion extending over the entire circumference on the peripheral surface is arranged inside a cylindrical member, and at least the cylindrical member is rotated while rotating the cylindrical member. The portion of the outer peripheral surface of the cylindrical member corresponding to the concave portion of the metal core is formed such that the radius of curvature of the pressing tip thereof is the concave portion of the metal core.
Pressing with a first peripheral surface pressing member that is larger than the radius of curvature of the portion to form a first constriction, and then applying a half curvature to the pressing tip
The second is smaller in diameter than the pressing tip of the first peripheral surface pressing member .
And pressed by the circumferential surface pressing member, in a state where <br/> only the side end portion of the constriction abuts against the said recess of the core metal, the stretched <br/> one Tsuso depth And the thickness of the side edge is
Method of forming a constriction of the circular tubular member which forms the second constriction is provided to be thinner than the thickness of the.

In the above method, the metal core may be divided into two parts in the length direction near the center of the concave portion, and the cylindrical member may be divided from both end surfaces to an end surface holding member. May be pinched. Further, one piece constituting the core metal may be joined to one of the two end face holding members, and the other piece may be joined to the other of the end face holding members.

In the method of the present invention, the first peripheral surface pressing member and the second peripheral surface pressing member may be processing rollers that rotate following the rotation of the cylindrical member.
Further, the core metal and the end face holding member may rotate together with the cylindrical member. Further, the first peripheral surface pressing member and the second
By forming the concave portions provided in the peripheral surface pressing member and the cored bar into predetermined shapes, a constriction having no bending point on the outer peripheral surface may be formed. Further, in the method of the present invention, only the formed constricted portion may be annealed.
Note that annealing is not necessarily required before the constriction processing.

[0016]

Further, according to the present invention, there is provided a cylindrical member having a constriction formed by any one of the above methods. Further, there is provided an anode container for a sodium-sulfur battery in which a constriction is formed by any of the above methods. Further, according to the present invention, there is provided a sodium-sulfur battery using the above-described anode container for a sodium-sulfur battery.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, first, as shown in FIG. 1, in a state where a core metal 30 having a concave portion 31 on a peripheral surface is inserted into a cylindrical member 34, first, a first peripheral surface pressing is performed. By pressing with the member 36a to form the first constriction 10a , and then pressing with the second peripheral surface pressing member 36b, the first constriction 10a is formed.
Forming a second constriction 10b deeper than the constriction
Curvature radius of the pressing tip of the first peripheral surface pressing member 36a
It is greater than the radius of curvature of the recess 31, and the radius of curvature of the pressing target end of the first circumferential surface pressing member 36a is larger than the radius of curvature of the pressing target end of the second circumferential surface pressing member 36b ing. Therefore, in the process of pressing by the second peripheral surface pressing member, only the side end of the first constriction is extended in a state of being in contact with the concave portion of the cored bar, and the depth thereof is increased. as a second constriction is formed that have a side end portion of the small wall thickness than the wall thickness of the tip constricted. This makes it possible to disperse the strain acting on the constricted tip.

That is, first, as shown in FIGS. 2 and 3, the cylindrical member 34 is evenly stretched by the first peripheral surface pressing member 36a, so that the entire wall thickness is uniform and The wall thickness is smaller than other portions of the cylindrical member 34
A first constriction 10a is formed. Next, FIGS. 4 and 5
As shown in FIG. 5, the first constriction 10a formed by the first peripheral surface pressing member 36a is
Accordingly, it is further extended, as shown in FIG. 6, but the final second constriction 10b is formed, pressed destination end of the second circumferential surface pressing member 36b has a first circumferential surface pressed Member 36
Because having a pressing destination end by Ri small radius of curvature of a, the first constriction 10a tip vicinity 50 of the initially formed second
Is fixed by the peripheral surface pressing member 36b , and its side end 51
Only the end portion 50 of the first constriction 10a is a portion other than the vicinity of the front end portion 50 of the first constriction 10a while being kept in contact with the concave portion 31.
Is further stretched. Therefore, the first constriction 10
a is being stretched in contact with the recess of the metal core,
The depth of the tip 50 of the second constriction 10b is increased by the thickness of the cylindrical member 34 constituting the anode container.
Ri becomes thin, a constricted shape which a thin side edge 51 than the thickness of the tip portion 50 to the second constriction 10b.

That is, the second constriction 10b manufactured by the above method has a sufficient spring effect and disperses the stress even when concentrated stress is applied, so that the cylindrical member is damaged. There is no. Meanwhile, constricted due to the side end portion in the constricted that Yusuke <br/> wall thickness thinner than the thickness of the tip, waist compression part can be a tensile strength to an appropriate size, cylindrical It is possible to sufficiently absorb the stress generated in the member. If the first peripheral surface pressing member, the second peripheral surface pressing member, and the concave portions provided in the cored bar are formed in a predetermined shape, it is possible to form a constriction having no bending point on the outer peripheral surface.

In the case of a cylindrical member used for an application other than the anode container, for example, a bellows or the like, if the first peripheral surface pressing member is pressed, the wall thickness in the vicinity of the tip of the constriction is reduced. Since the thickness can be increased as compared with the method, it is possible to form a constriction having sufficient strength, a spring effect, and durability without pressing by the second peripheral surface pressing member. In this case, the radius of curvature of the pressing destination end of the peripheral surface pressing member, it is necessary to be larger than the radius of curvature of the bottom of the recess provided in the core metal.

FIG. 1 shows an example of a method for forming a constriction according to the present invention.
Shown in

First, as shown in FIG. 1A, a metal core 30 joined to an end face holding member 33 from both sides of an opening of the cylindrical member 34 inside the cylindrical member 34.
Is inserted, and the cylindrical member 34 is clamped from both end surfaces by the end surface clamping member 33 in a state where the fragments constituting the core metal 30 are in contact with each other. It is preferable that the core metal 30 be divided into two in the length direction near the center of the concave portion 31. Otherwise, after making the constriction, the core metal 3
This is because it becomes difficult to pull out 0 from the cylindrical member 34. An elastic body 46 such as a rubber or a spring is provided between one of the end faces of the cylindrical member 34 and one of the end face holding members 33.
Is preferably arranged. This is because there is a gap between the pieces constituting the metal core 30 due to variations in the length of the cylindrical member 34 used, or a compressive force is applied to the cylindrical member 34 when the pieces constituting the metal core 30 are brought into contact with each other. This is to prevent the occurrence of the deformation and to prevent a variation in the distance from the end face of the cylindrical member 34 to the position where the constriction is formed. The insertion of the core 30 into the cylindrical member 34 is performed as follows.
This is performed by advancing the fragments of the core metal 30 by an air cylinder or the like.

Next, as shown in FIG. 1B, while rotating the end face holding member 33 together with the metal core 30 and the cylindrical member 34, the end face holding member 33 is inserted into the concave portion 31 of the metal core 30 on the outer peripheral surface of the cylindrical member 34. The first constriction 10a is formed by applying pressure to the corresponding portion with the first peripheral surface pressing member 36a. At this time, the elastic body 46 rotates one end of the end face holding member 33 by the core metal 30, the cylindrical member 34, and the end face holding member 3.
Plays the role of communicating to the other of the three. In addition, the end face holding member 3
It is also possible to rotate only the cylindrical member 34 without rotating the core 3 and the metal core 30. A processing roller that rotates following the rotation of the cylindrical member 34 is preferably used as the first peripheral surface pressing member 36a.

Next, as shown in FIGS. 1 (c) and 1 (d), the final second constriction 10b is formed by applying pressure with the second peripheral surface pressing member 36b while continuing to rotate. Form. A processing roller that rotates following the rotation of the cylindrical member 34 is preferably used as the second peripheral surface pressing member 36b.

After forming the constriction, the rotation is stopped and the core metal 30 is attached to the cylindrical member 3 by an air cylinder.
Pull out from 4. By attaching a bottom plate to the cylindrical member 34 provided with the second constriction 10b as described above, an anode container for a sodium-sulfur battery is obtained. When used as an anode container, only the vicinity of the tip of the formed constriction may be annealed. This is because the annealing has the advantage that the hardness and strength near the tip of the neck become small, and the strain applied to the entire anode container can be absorbed by the neck.

[0027]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) Length 500 mm, outer diameter 89
± 0.1 mm, inner diameter 84.4 ± 0.1 mm, wall thickness 2.3
A constriction having a width of 18 mm and a depth of 8.9 mm (inner diameter side depth of 8.2 mm) was formed on the cylindrical member of t by the following method.

As shown in FIG. 1A, the cylindrical member 3
The pieces of the core metal 30 joined to the end face holding members 33 were inserted into the inside of each of the members 4 from both the openings of the cylindrical member 34 by an air cylinder. When the pieces of the cored bar 30 are joined together, a recess 31 having a width of 18 mm, a depth of 8.2 mm, and a radius of curvature (R) of 4 at the bottom is formed at the joint, as shown in FIG.

Next, as shown in FIG. 1B, while holding the cylindrical member 34 with the end face holding member 33, the end face holding member 33 is rotated together with the metal core 30 and the cylindrical member 34 to form a cylindrical member. The concave portion 31 of the core metal 30 in the outer peripheral surface of the member 34
By applying pressure to the portion corresponding to the above by the processing roller 36a, a first constriction 10a as shown in FIG. 3 was formed. The thickness of the first constriction 10a was 2.2 t, the outer diameter was 77.4 mm, and the inner diameter was 73.0 mm. still,
The processing rollers 36a, has a cross-sectional shape as shown in FIG. 10, the curvature of the pressing destination end radius (R) is used as a 15. The rotational speed of the cylindrical member 34 is 165 rpm, and the moving speed of the processing roller 36a is 0.8 mm /
Seconds.

Next, as shown in FIGS. 1C and 1D, while the rotation of the cylindrical member 34 is maintained, the final second constriction 10 b is formed by the processing roller 36 b.
As the working roller 36b, has a cross-sectional shape as shown in FIG. 11, the curvature of the pressing destination end radius (R) was used as the 3. The rotation speed of the cylindrical member 34 is 165 rpm.
The moving speed of the processing roller 36b is 0.5 mm on average.
/ Sec.

After the formation of the second constriction 10b, the rotation was stopped and the core 30 was pulled out of the cylindrical member 34 by an air cylinder. As shown in FIG.
The thickness of the tip of the formed second constriction 10b is 1.6 ± 0.1 mm with respect to the actual design value of 1.6 ± 0.15 mm, and the minimum thickness of the side end of the second constriction 10b. Was 1.3 ± 0.1 mm against the actual design value of 1.3 ± 0.15 mm. The inner diameter of the constricted portion is 68.0 ± 0.25 m, which is the actual design value.
m was 68.0 ± 0.2 mm, and the neck diameter was 71.2 ± 0.1 mm.

Table 1 shows the outer diameter of the constriction, the inner diameter of the constriction, etc. during the formation of the first constriction, the completion of the formation of the first constriction, the formation of the final constriction, and the completion of the formation of the final constriction. I do.

[0034]

[Table 1]

15 to 18 show photographs of the appearance and cross section of the constriction at each stage shown in Table 1. Further, Table 2 shows various dimensions of the constrictions formed, and their average values and standard deviations for the ten cylindrical members having constrictions formed under the same conditions.

[0036]

[Table 2]

Next, three of the ten cylindrical members having the constriction are locally annealed in the vicinity of the tip of the formed constriction, that is, in a region of 9 mm on both sides from the top of the constriction. Were measured for compressive strength and Pickers hardness. The results are shown in Tables 3 and 4 and FIG.

[0038]

[Table 3]

[0039]

[Table 4]

The sectional structures of the constricted portion before and after local annealing are shown in photographs in FIGS. 19 and 20, respectively.

FIGS. 21 and 22 show graphs obtained by measuring the strain of the constriction at the time of 1.0 mm compression and 1.0 mm tension, respectively. FIG. 21 and FIG.
From FIG. 2, it can be seen that the strain distribution in the constricted portion (the portion from the center of the constriction to about 9 mm) is in a small range of ± 2 × 10 ⁻² .

Comparative Example 1 A constriction having a width of 18 mm and a depth of 8.9 mm was formed on a cylindrical member having the same dimensions as the cylindrical member used in Example 1 by the method shown in FIG. .

First, pieces of the core metal 30 having an outer diameter of 84.4 mm were respectively inserted into the cylindrical member 34 from both openings of the cylindrical member 34 by an air cylinder. When the pieces of the core metal 30 are joined together, a concave portion 31 having a width of 18 mm and a depth of 8.2 mm is formed at the joint.
Is formed.

Next, the mandrel 30 and the cylindrical member 34 are rotated, and pressure is applied to a portion of the outer peripheral surface of the cylindrical member 34 corresponding to the concave portion 31 of the mandrel 30 by the processing roller 36 to form the constriction 10. Was formed.

After forming the constriction 10, the core metal 30 was pulled out of the cylindrical member 34 by an air cylinder. The thickness of the tip of the formed constriction 10 is 1.0 m
m, and the thickness of the side edge of the constriction 10 was 1.2 mm.

[0046]

In the method for forming a constriction on a cylindrical member according to the present invention, the radius of curvature of the pressing tip is determined by adjusting the radius of curvature of the core metal.
By the first peripheral surface pressing member having a larger radius of curvature of the concave portion, the peripheral surface of the cylindrical member is extended evenly, and the entire wall thickness is equal, and the wall thickness is more than that of other portions of the cylindrical member. after forming the small first constriction, the pressing info
The radius of curvature of the end is greater than the pressing tip of the first peripheral surface pressing member.
Side edges of the first constriction due to the small second peripheral surface pressing member
While stretching the tip other than the portion in a state in which only the in contact with the recess of the core part, the final constricted by a deep
(Second constriction) is formed. Accordingly, the side end portions that have a thickness thinner than the thickness of the above end portion is formed in the constriction. That is, in the constriction formed by the method of the present invention, since the vicinity of the constriction tip is thick, it has a sufficient spring effect, and even if stress is concentrated, the cylindrical member is not damaged. Absent. On the other hand, because the side end portion was thin Ri by thick <br/> wall of the tip of the constriction, compression of the constricted portion, the tensile strength can be appropriate size, the stress generated in the cylindrical member sufficiently Can be absorbed.

[Brief description of the drawings]

FIG. 1 is a process chart showing an example of a method for forming a constriction on a cylindrical member of the present invention.

FIG. 2 is a schematic cross-sectional view showing a process of forming a constriction when the constriction is formed by the method of the present invention.

FIG. 3 is a schematic cross-sectional view showing a process of forming a constriction when the constriction is formed by the method of the present invention.

FIG. 4 is a schematic cross-sectional view showing a process of forming a constriction when the constriction is formed by the method of the present invention.

FIG. 5 is a schematic cross-sectional view showing a process of forming a constriction when the constriction is formed by the method of the present invention.

FIG. 6 is a schematic cross-sectional view showing a process of forming a constriction when the constriction is formed by the method of the present invention.

FIG. 7 is a schematic sectional view showing an example of a conventional method for forming a constriction on a cylindrical member.

FIG. 8 is a sectional view showing a structure of a sodium-sulfur battery.

FIG. 9A is a schematic diagram showing a state of connection between a solid electrolyte tube and a cylindrical member. (B) It is explanatory drawing which shows the load applied to the tube bottom of a solid electrolyte tube.

FIG. 10 is a cross-sectional view illustrating an example of a processing roller used in the method of forming a constriction on a cylindrical member according to the present invention.

FIG. 11 is a cross-sectional view showing another example of the processing roller used in the method of forming a constriction on a cylindrical member according to the present invention.

FIG. 12 is a cross-sectional view showing an example of a concave portion provided in a core used in the method of forming a constriction in a cylindrical member according to the present invention.

FIG. 13 is a graph showing Pickers hardness at each point of a constriction.

FIG. 14 is a sectional view showing an example of a constriction formed by the method of the present invention.

FIG. 15 is a photograph showing (a) the appearance and (b) a cross section of the constriction during the formation of the first constriction.

FIG. 16 is a photograph showing the (a) appearance and (b) cross section of the constriction at the completion of the formation of the first constriction.

FIG. 17 is a photograph showing (a) the appearance and (b) a cross section of a constriction during formation of a final constriction.

FIG. 18 is a photograph showing the (a) appearance and (b) cross section of the constriction at the time when the final constriction is completed.

FIG. 19 is a photograph showing a cross-sectional structure of a neck before local annealing.

FIG. 20 is a photograph showing a cross-sectional structure of a neck after local annealing.

FIG. 21 is a graph showing strain at the time of 1.0 mm compression of a neck after local annealing.

FIG. 22 is a graph showing a strain at the time of pulling 1.0 mm of a neck after local annealing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulator ring, 2 ... Solid electrolyte tube, 3 ... Joint part between insulator ring and solid electrolyte pipe, 4 ... Joint part between insulator ring and cylindrical metal fitting, 5 ... ..Welded portion between cylindrical fitting and anode container, 6 ... Anode container, 7 ... Cylindrical fitting, 8 ...
Anode container lid, 9: welded part between cylindrical member and anode container lid, 10: constriction, 11: conductive material for anode, 12: molten metal sodium, 13: cylindrical member , 14 ... joining material, 15 ... joining glass, 16 ... strength measuring jig, 17 ...
・ Sodium-sulfur battery, 18 ・ ・ ・ Ring bottom, 19 ・ ・
.Flange, 20 ... sulfur or sodium polysulfide, 21 ..
・ Pipe, 22 ・ ・ ・ Constriction length, 30 ・ ・ ・ Core bar, 31 ・ ・ ・
Recessed part, 33 ... end face holding member, 34 ... cylindrical member, 36
... periphery pressing member (processing rollers) 41 and 43 ... circumferential surface pressed destination end of the pressing member, 46 ... elastic body, 50 ... tip portion, 5
1 ... side end .

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21D 17/04 B21D 15/04 B21H 1/00-9/00 H01M 2/02 H01M 10/39

Claims (11)

(57) [Claims] 1. A core metal having a concave portion extending over the entire circumference on a peripheral surface is disposed inside a cylindrical member, and at least the cylindrical member is rotated while rotating the cylindrical member at least on the outer peripheral surface of the cylindrical member. The part corresponding to the recess ,
The radius of curvature of the pressing tip is half the curvature of the concave portion of the cored bar.
A first Ku <br/> fin formed by pressing in diameter larger than the first circumferential surface pressing member, then the radius of curvature of the pressing tip the first
1 by pressing the first constriction at the pressing tip is smaller than the second circumferential surface pressing member of the peripheral surface pressing member, the first neck <br/> Re side edge only the core metal in a state in which the of the recessed portion abuts, by increasing the depth of the elongated Sorcerer Tsuso, of the end portion
The second neck so that the thickness is less than the thickness of its tip
Method of forming a constriction of the cylindrical member, characterized that you formed les. 2. The method for forming a constriction in a cylindrical member according to claim 1, wherein the core metal is divided into two parts in the length direction near the center of the concave part. 3. The method for forming a constriction in a cylindrical member according to claim 1, wherein the cylindrical member is sandwiched from both end surfaces thereof by end face clamping members. 4. The cylindrical member according to claim 2, wherein one of the pieces constituting the metal core is joined to one of the two end face holding members, and the other piece is joined to the other of the end face holding members. The method of forming the constriction. 5. The method according to claim 1, wherein the first peripheral surface pressing member and the second peripheral surface pressing member are processing rollers that rotate following the rotation of the cylindrical member. The method of forming a constriction on a cylindrical member. 6. The method for forming a constriction in a cylindrical member according to claim 1, wherein the core metal and the end face holding member rotate together with the cylindrical member. 7. A constriction having no bending point on the outer peripheral surface by forming the first peripheral surface pressing member, the second peripheral surface pressing member, and the concave portion provided on the cored bar into a predetermined shape. The method for forming a constriction in a cylindrical member according to any one of claims 1 to 6. 8. The method of forming a constriction on a cylindrical member according to claim 1, wherein only the tip of the constriction is annealed. 9. cylindrical member, characterized in that the formation of the constriction by the method according to any one of claims 1-8. 10. A sodium-containing material, wherein the constriction is formed by the method according to any one of claims 1 to 8.
Anode container for sulfur batteries. 11. A sodium-containing battery comprising the anode container for a sodium-sulfur battery according to claim 10.
Sulfur battery.