JP6189121B2 - Metal C-ring and manufacturing method thereof - Google Patents

Description

  The present invention relates to a metal C-ring and a manufacturing method thereof.

  In general, it is relatively easy to manufacture a metal C-ring having a circular overall shape, and both ends of a metal strip are connected by welding or the like, or a thin pipe is cut into a circular short cylindrical material. (Also referred to as a hoop material) (see, for example, Patent Document 3). That is, such a circular short cylindrical material (hoop material) is formed into a cross section C shape by a pair of molds, or gradually formed into a cross section C shape while being squeezed by a pair of rolls. Methods are known. (The manufacturing method of such a known circular metal C ring having a general shape will be described in more detail with reference to FIGS. 1 to 3 described later.)

However, as a manufacturing method of a metal C ring having a rectangular overall shape (see Patent Document 1), a method of punching the entire shape from a thin plate into a rectangular ring shape with a die, and thereafter forming the cross section into a C shape, or A method has been used in which a whole is formed into a flat plate-like annular shape by welding or the like and then bent by a mold.
In the conventional manufacturing method of such an overall rectangular metal C-ring, in order to manufacture metal C-rings of various sizes, large and small sizes, separate jigs and dies are required for each size, and the processing efficiency is also high. There was a problem of being low.

  Alternatively, as a prior art, there is a proposal to form a rectangular short cylindrical material by connecting both ends of a metal strip by welding or the like, and then gradually form this into a C-shaped cross section. There is a problem that the dimensional accuracy of the final product is poor and the work efficiency is poor (for example, see Patent Document 2).

JP 2005-54992 A JP-A-10-281287 JP-A-1-172682

  Thus, in the conventional manufacturing method, there is a problem that separate jigs and dies are required for each size of the metal C ring, and work efficiency is poor, or special skill is required for processing, or There was a problem that only small quantities could be produced.

  Therefore, the present invention can be easily manufactured with few jigs and requires no skill, is suitable for mass production, has high dimensional accuracy, and has stable and excellent sealing performance. An object is to provide a metal C ring having a rectangular shape. Another object of the manufacturing method of the present invention is to provide a method for efficiently manufacturing an overall rectangular metal C ring without requiring separate jigs and dies for each size.

Therefore, the metal C ring according to the present invention has an overall shape of a rectangular shape having a long side and a short side, and a joint portion formed by welding, pressure welding, or adhesion is disposed on the short side.
Moreover, it is comprised from the core material and the exterior material of the cross-sectional C shape which coat | covers this core material, The whole shape is a rectangular shape which has a long side and a short side, Comprising: The opening part of the said exterior material is an outer peripheral side In addition, a seam portion formed by welding, pressure welding or adhesion of the exterior material is disposed on the short side.
Further, the outer packaging material is composed of an inner layer and an outer layer, and the metal material of the outer layer is manufactured so that the yield point is lower than the metal material of the inner layer and plastic deformation is easy, and the overall shape is the rectangular shape. When the longitudinal tension is applied, the outer layer is configured to be more plastically deformed in the direction of diameter reduction of the cross section than the inner layer to grip the inner layer.
The rectangular shape has rounded corners at four corners, and the radius of curvature of the rounded corner is set to 4 to 25 times the outer diameter of the exterior material.

And the manufacturing method of the metal C ring which concerns on this invention manufactures the metal curling part formation receptacle for producing the metal C ring intermediate body whose whole shape is circular, and then forming four corners of a rectangle. Corresponding to the inner peripheral side of the body, the intermediate body is given longitudinal tension by the movement of the curved portion forming receiver, and the overall shape is formed while forming the four corners having the curved portion by the receiver. This is a method of plastic deformation in a rectangular shape.
In addition, the four above-described curved portions forming receivers are attached to the first member and the second member, which are reciprocally moved so as to be relatively close to each other. The short side is formed by each of the two receivers, and the long side is formed by moving the first member and the second member in the separating direction.
Preferably, the rounded bent portion forming receiver is a rotatable roller.
Further, a seam formed by welding, pressure welding or adhesion of a metal C ring intermediate body is arranged between the two receivers of the first member or between the two receivers of the second member. This is a method in which the tension acting on the long side by the movement of the first member and the second member in the separation direction indirectly acts on the joint portion on the short side via the support.

The metal C-ring of the present invention can be manufactured without applying an excessive tensile force to a joint portion such as welding that is easily damaged during the manufacturing. And it is excellent in sealing performance and the dimensional accuracy is also stable and excellent.

  In addition, according to the metal C-ring manufacturing method of the present invention, it has been possible to realize mass production of a generally rectangular metal C-ring at a low cost for the first time. In addition, the number of jigs and dies can be minimized, and the processing efficiency can be remarkably improved.

It is sectional explanatory drawing explaining the basis of the manufacturing method. It is sectional explanatory drawing explaining the basis of the manufacturing method. It is sectional explanatory drawing explaining the basis of the manufacturing method. It is a principal part fracture perspective view showing one embodiment of a metal C ring of the present invention. It is a front view of the state which showed one embodiment of the manufacturing method of the metal C ring concerning the present invention, and set the metal C ring intermediate body of whole shape circle. It is the front view which showed the state in the middle of transforming the whole shape of a metal C-ring from the circular shape of an intermediate body to a rectangle. It is a front view which shows the state which changed the whole shape of the metal C ring to the rectangle. It is an AA expanded sectional view of FIG. It is a front view of the whole shape of one embodiment of a metal C ring concerning the present invention. It is BB expanded sectional drawing of FIG. It is an expanded sectional view showing other embodiments of a metal C ring. It is a front view of the state which showed other embodiments of the manufacturing method of the metal C ring concerning the present invention, and set the metal C ring intermediate body of the whole shape circle. It is the front view which showed the state in the middle of transforming the whole shape of a metal C-ring from the circular shape of an intermediate body to a rectangle. It is a front view which shows the state which changed the whole shape of the metal C ring to the rectangle. It is a graph which shows the relationship between a displacement and a load in the case of changing from a circle to a rectangle.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
FIG. 9 shows a metal C-ring 1 manufactured by the manufacturing method according to the present invention, and this metal C-ring 1 is a transverse having an opening 10 opening in the (radial) outward direction as shown in FIG. As shown in FIG. 9, the shape is a rectangular shape having a long side 21 and a short side 22 (rectangular closed ring) as shown in FIG. Arranged on the short side 22.

  Also, as shown in FIGS. 4 and 10, a core material 11 made of a coil spring (or an elastic wire material such as rubber not shown) and a C-shaped exterior material 12 covering the core material 11 are provided. It is configured. 4 and 10, the exterior material 12 is composed of an inner layer 12A and an outer layer 12B, and the metal material of the outer layer 12B is selected to have a lower yield point than the metal material of the inner layer 12A and is easily plastically deformed. Yes. For example, the inner layer 12A is made of a hard material having a high yield point such as stainless steel or a Ni-based alloy such as a Ni—Fe—Cr—Nb—Mo alloy. As the outer layer 12B, a soft material having a low yield point such as aluminum, aluminum alloy, silver, or silver alloy is used. As described above, the outer layer 12B is made of a soft material and a material having a low yield point, so that the “familiarity” with respect to each of the two planes can be obtained in a sealed use state in which the metal C ring 1 is attached between two opposed planes. In addition to this, in the present invention, according to the manufacturing method described later, other actions and effects can be obtained (described later).

Next, the overall shape will be described with reference to FIG. 9. It is a rectangular shape (rectangular shape) with rounded corners 3 formed at four corners, and the radius of curvature of the rounded corners 3 (on the inner side surface). R ₃ is 4 times or more, preferably 5 times or more, of the outer diameter D ₁₂ (in the cross section) of the exterior material 12. The upper limit need not be specified, preferably not more than 25 times the outer diameter D _12. If it is less than the lower limit value, deformation from a circular shape to a rectangular shape (see FIG. 5, FIG. 6, FIG. 7 or FIG. 12, FIG. 13, FIG. 14) described later tends to be difficult. Moreover, if the upper limit is exceeded, there is a possibility that the shape of the rectangular window portion in use does not match.

Further, in FIG. 9, the following equation is established between the long side dimension L ₂₁ and the short side dimension S ₂₂ measured on the inner peripheral side of the entire rectangle.
1.5 ≦ L ₂₁ / S ₂₂ ≦ 3
Preferably
1.8 ≦ L ₂₁ / S ₂₂ ≦ 2.2
Specifically, for example, L ₂₁ = 700 mm, S ₂₂ = 350 mm, etc. are set.

In the embodiment shown in FIG. 4 and FIG. 8 to FIG. 10, it is composed of a core material 11 and an exterior material 12, and the overall shape is a rectangular shape having a long side 21 and a short side 22. 12 opening portions 10 are arranged along the outer peripheral side (radially outward), and the joint portion 20 of the exterior material 12 is arranged on the short side 22.
By the way, as the seam part 20, there can be mentioned one by welding (welding seam part), one by pressure welding (pressure welding seam part), one by adhesion (adhesion seam part), etc., but there is little variation between lots, In addition, a welded seam is preferable from the viewpoints of less variation in the seam and stability.

  Next, a method for manufacturing a metal C ring according to the present invention will be described. 1 to 3 sequentially illustrate the steps of manufacturing the metal C-ring intermediate 5 having a circular overall shape. In order to make the inner layer 12A of FIG. 4, both ends of the metal strip 6A are connected by joints 7A such as welding, adhesion or pressure welding (indicated by a two-dot chain line), and a circular short cylindrical material (hoop material) Make 8A. Further, in order to make the outer layer 12B of FIG. 4, both ends of another metal strip 6B are connected by joints 7B such as welding, adhesion or pressure welding (indicated by a two-dot chain line), and a circular short cylindrical material (Hoop material) 8B is manufactured.

Next, as shown in FIG. Next, the core material 11 is inserted into the upper part of FIG. 2 in a U-shape as shown by a two-dot chain line by bending or rolling, and further plastically processed to a C-shape. 3, the metal C-ring intermediate body 5 having a circular overall shape and an outward C-shaped cross section is manufactured.
Although not shown, after the core material 11 is inserted into the hoop material 8A and made into a C shape, the hoop material 8B is placed along the outside of the C-shaped hoop material 8A, and the hoop material 8B is placed on the outer periphery of the hoop material 8A. You may make it into a C shape along with.
The latter is preferable because the hoop materials are processed separately, and can be manufactured without considering the expansion and contraction of each hoop material due to the processing, as compared with the case of simultaneous processing.
Further, when the exterior material 12 has two layers, the joint portions 20 and 20 of the hoop materials 8A and 8B are not necessarily matched.

  By the way, the manufacturing method of the intermediate-shaped circular intermediate body 5 described above with reference to FIGS. 1 to 3 is a known method, which is also described in the above-mentioned Patent Document 3 and is widely implemented. It is also free to produce the intermediate body 5 using a manufacturing method other than those described in the above. However, the subsequent steps are unique and will be described in detail below.

  That is, as shown in FIG. 5, the curved portions forming receptacles 30, 30, 31, 31 for forming the four corners of the rectangle are made to correspond to the inner peripheral side of the intermediate body 5, and the curved portions 3 ( The circular intermediate body 5 as shown in FIG. 5 is shown in FIG. 6 by the movement of the curved portions 30, 31, 31, 31 in the direction of arrows G, G to form Through such a barrel shape (a shape in which the center of the long side swells from the short side of both ends), it is further deformed to the rectangular shape shown in FIG. That is, the longitudinal tension F is applied to the exterior body 12 as a linear body, and the curved portions 3, 3, 3, 3 are formed at the four corners by the receivers 30, 30, 31, 31. 7 and 9 are plastically deformed into an overall rectangular shape as shown in FIGS.

More specifically, the four rounded curved portion forming receptacles 30, 30, 31, 31 are reciprocally moved in the direction of the arrow G and in the opposite direction so as to be relatively close to each other. Two pieces are attached to the second member 14 separately.
Further, the two rounded curve part forming receivers 31, 31 may be fixed, and the two rounded curve part forming receivers 30, 30 may be relatively close to and separable from each other.
The latter is preferable because the equipment can be configured simply. In the example shown in the figure, the upper first member 13 has two receivers 30 and 30 attached thereto, and the lower second member 14 has other two receivers 31 and 31 attached thereto. Yes.

As is apparent from FIGS. 9 and 7, the two receiving members 30, 30 of the first member 13 form the upper short side 22 of FIG. 9, while the two receiving members of the second member 14. The short side 22 in the lower part of FIG. In addition, the long sides 21 and 21 are formed by the movements G and G in the separation direction of the first member 13 and the second member 14.
As is apparent from FIG. 8, the rounded bent portion forming receivers 30 and 31 are rollers R ₀ that are rotatable around an axis L ₁₅ of the pivot shaft 15.

As shown in FIG. 5, the joint portion 20 of the intermediate body 5 is disposed between the two receiving members 30, 30 of the first member 13, preferably in the vicinity of the center. With this arrangement, the tension F (see FIGS. 7 and 6) acting on the long side 21 by the movement of the first member 13 and the second member 14 in the separating direction (see arrow G) causes the receiving members 30 and 30 to move. It acts indirectly on the joint 20 on the short side 22 side.
Further, when the exterior material 12 has a two-layer structure of the inner layer 12A and the outer layer 12B, the joint portion 20 of the outer layer 12B is between the two receivers 30 and 30 of the first member 13, preferably in the vicinity of the center. (The seam portion 20 of the inner layer 12A may not be between the two receiving members 30 and 30 of the first member 13. In a preferred embodiment, the seam of the inner layer 12A and the outer layer 12B may be used. The portion 20 may be disposed between the two receiving members 30 and 30 of the first member 13, preferably in the vicinity of the center.
When the core material 11 is a coil spring, the inner layer 12A is made of stainless steel, and the outer layer 12B is made of aluminum or an aluminum alloy, the joint portion 20 of the inner layer 12A has sufficient elongation and strength even when deformed from a circle to a rectangle. Breakage at the seam 20 is unlikely to occur.
On the other hand, when the seam portion 20 of the aluminum or aluminum alloy of the outer layer 12B is deformed from a circular shape to a rectangular shape, the seam portion 20 does not have an elongation and strength that can withstand the deformation. The seam portion 20 of the outer layer 12B must be disposed between the two receptacles 30 and 30 of the first member 13, preferably in the vicinity of the center.

  The seam 20 of the intermediate body 5 is disposed between the two receiving members 31 and 31 of the second member 14 (preferably near the center) (not shown), and the first member 13 and The tension F (see FIGS. 7 and 6) acting on the long side 21 by the (relative) separation movement of the second member 14 in the direction of arrow G causes the lower side 22 on the lower side through the support members 31, 31. It is also preferable to transmit it indirectly to the joint portion 20.

As shown in FIG. 8, the roller R ₀ is provided with both flange portions 16 and 16 projecting at a sufficient height, and the U-shaped groove 18 is an outer diameter in the cross-sectional shape of the intermediate body 5. And a groove width dimension W ₁₈ equal to the outer diameter dimension. Further, the groove bottom radius R ₁₈ of the groove 18, to the radial dimension of the cross-sectional shape of the intermediate 5 is desirable. By configuring the concave groove 18 and the flanges 16 and 16 of the roller R ₀ as described above, when the large tension F acts and plastically deforms (as shown in FIGS. 6 to 7), the metal C ring 1 The cross sectional shape of the original intermediate 5 can be maintained. That, together with the outer diameter D ₁₂ of at metal C-ring 1 on the finished product shown in FIG. 9 is maintained equal to the outer diameter of the intermediate 5, (as shown in FIG. 10) the perfect circular shape Can be maintained. The groove bottom radius R ₁₃ of the groove 18 shown in FIG. 8, a phase equal to the radius of curvature R ₃ of the rounded curved portion 3 shown in FIG.

  FIG. 11 is an enlarged cross-sectional view of another embodiment shown corresponding to FIG. 10, in which the exterior material 12 is formed with only one layer. It is also free to have such a one-layer exterior material 12. Although not shown, the core material 11 shown in FIG. 10 or FIG. 11 may be provided with an elastic body such as a linear rubber material instead of a coil spring.

Next, FIGS. 12 to 14 illustrate another embodiment instead of the above-described FIGS. It is shown that the rounded curved portion forming receivers 30 and 31 can be freely changed from the roller R ₀ to the arc-shaped fixing members 32 and 33. Each of the fixing members 32 and 33 has, for example, a quadrangular arc shape, and a pair of fixing members 32 and 32 are fixed to the first member 13, and another pair of fixing members is attached to the second member 14. 33 and 33 are fixed. The curvature radii R ₃₂ and R ₃₃ of the sliding surface 34 on the outer peripheral side of each fixing member ₃₂ and ₃₃ are set to be equal to the curvature radius R ₃ of the rounded curved portion 3 of the metal C ring 1 as a finished product shown in FIG. To do.

By the way, the cross-sectional shape of the outer peripheral sliding surface 34 of each of the fixing members 32 and 33 is formed as a sliding concave groove surface having the same radius R ₁₈ as the concave groove 18 shown in FIG. 8 or a slightly larger radius. Is desirable. However, if desired, a smooth cylindrical surface in which no concave groove is formed on the outer peripheral sliding surface 34 of each of the fixing members 32 and 33 can be used (this is the same for the roller _{R0 in} FIG. 8).

  The metal C-ring manufacturing method in the embodiment shown in FIGS. 12 to 14 is the same as the manufacturing method described in FIGS. 5 to 7, and the same reference numerals indicate the same configuration. A duplicate description is omitted here.

  Next, in the graph shown in FIG. 15, the displacement ΔH is taken on the horizontal axis and the load Wg is taken on the vertical axis, and as shown in FIGS. It shows how the load Wg in the direction of the arrow G applied to the annular intermediate body 5 changes according to the change (displacement; ΔH) of the distance H between the upper and lower holders 30 and 31.

  That is, the state shown in FIG. 5 (FIG. 12) corresponds to the symbol a in FIG. 15, and the displacement ΔH advances rapidly even if the load Wg is small. Subsequently, the state shown in FIG. 6 (FIG. 3) corresponds to the region b in FIG. 15 and is a region where the load Wg suddenly increases linearly by the displacement ΔH of the distance H, and the tension F is The intermediate body 5 expands (from a circular shape) and elastically deforms into a rectangular shape while deforming while increasing rapidly.

  A cross in FIG. 15 indicates a region where the load Wg rapidly increases with respect to the displacement ΔH along the inclined two-dot chain line 24, and sharply if the load Wg slightly increases away from the two-dot chain line 24. A displacement point with respect to a region (symbol e) where the displacement ΔH occurs is shown. This displacement point (x mark) is called the apparent yield point.

In the present invention, the state of plastic deformation to the final overall shape rectangle shown in FIG. 7 (FIG. 14) is shown in FIG. That is, in the present invention, a final load Wc that is larger than the load Wx of the apparent yield point (x mark) is applied.
A final load Wc is set between the two loads Wx and Wc so that the following equation is established.
1.001 · Wx ≤ Wc ≤ 1.10 · Wx
More preferably,
1.005 ・ Wx ≦ Wc ≦ 1.05 ・ Wx
And

  As described above, the reason for applying the final load Wc larger than the apparent load Wx is as follows. That is, as shown in FIG. 5 (FIG. 13) to FIG. 6 (FIG. 14), in the course of deforming the overall shape into a rectangle, due to the circumferential length difference between the inner and outer circumferences, This is because, if the apparent yield point is the final, buckling may occur.

  Alternatively, in the exterior material 12 composed of the inner layer 12A and the outer layer 12B shown in FIGS. 4 and 10, etc., the yield point of the material (metal material) is different, and even if one of them is plastically deformed, the other is slightly elastic. If there is a residual, there is a possibility that the above buckling or local deformation may occur, so it is desirable to load up to the final load.

When the metal material of the outer layer 12B has a lower yield point and is more easily plastically deformed than the metal material of the inner layer 12A, when the entire shape is rectangular (see FIGS. 7 and 14), the longitudinal tension F As a result, the outer layer 12B is more plastically deformed in the direction of diameter reduction of the cross section than the inner layer 12A, and the inner layer 12A can be gripped from the outside to form two layers densely without a gap.
By the way, in this invention, the longitudinal direction tension F shows the tension | tensile_strength (load) which acts in the same direction as the side which becomes a long side, when it makes it a rectangle.

  Applications of the metal C ring 1 according to the present invention include a semiconductor manufacturing apparatus, a pressure vessel, a vacuum vessel, and the like. As described above, in the manufacturing method according to the present invention, a metal C ring having a circular overall shape that has been widely used in the past is used as a starting point, and this is skillfully plastically deformed into a rectangular shape. And jigs and tools can be omitted, and this method is also suitable for small-lot, multi-product production.

  In the metal C-ring manufacturing method according to the present invention, the joint portion 20 is difficult to stretch and easily breaks. Therefore, it is desirable to perform heat treatment at a temperature at which the material of the circular intermediate body 5 shown in FIG. Also, as shown in FIG. 4 and FIG. 10, in the case of the two-layer type metal C ring 1, the outer layer 12B is more likely to break than the inner layer 12A, so it is desirable to heat-treat at a temperature at which the outer layer 12B softens. When the outer layer 12B is a soft metal, it is desirable to select a temperature at which the outer layer 12B softens without the inner layer 12A softening.

  Since the plastic processing to the overall shape rectangle described in FIGS. 7, 14 and 15 is likely to cause a difference in mechanical strength (hardness) between the rounded curved portion 3, the linear long side 21, and the short side 22, It is also preferable to perform a heat treatment (as described above).

  As described above, the metal C ring according to the present invention has a rectangular shape having a long side 21 and a short side 22 and the seam portion 20 is disposed on the short side 22. A circular metal C-ring (intermediate body 5) is used as a base, and the four receivers 30, 30; 31, 31 are moved G as shown in FIG. 6 and FIG. When Wg is applied, an indirect tensile force acts on the short side 22 even though a tensile force F or an impact acts directly on the long sides 21, 21, and the holders 30, 30; Since the impact is relieved and damage such as cracks does not occur in the joint portion 20, it is easy to manufacture and the quality is stably stabilized without generating defective products.

  Moreover, it is comprised from the core material 11 and the exterior material 12 of the cross-sectional C shape which coat | covers this core material 11, Comprising: The whole shape is a rectangular shape which has the long side 21 and the short side 22, Comprising: The said exterior material 12 The opening 10 is arranged along the outer peripheral side, and the seam 20 of the exterior material 12 is arranged on the short side 22, so that the opening 10 is a curved portion forming receptacle. 30 and 31 can prevent abnormal deformation and damage, and the rounded curved portion 3 can be formed in a highly accurate and stable cross-sectional shape. Further, using the metal C ring (intermediate body 5) having a circular overall shape as a base, as shown in FIG. 6 and FIG. 7 (FIGS. 13 and 14), four receivers 30, 30; Thus, when the load Wg is applied, even though the tensile force F or impact acts directly on the long sides 21 and 21, an indirect tensile force acts on the short side 22 and the receptacles 30, 30 ; 31 and 31 also reduce the impact, and damage such as cracks does not occur in the seam portion 20. Therefore, it is easy to manufacture and the quality is stably stabilized without generating defective products.

  The exterior material 12 includes an inner layer 12A and an outer layer 12B. The metal material of the outer layer 12B has a lower yield point and is more easily plastically deformed than the metal material of the inner layer 12A, and the overall shape is the rectangular shape. Since the outer layer 12B is configured to be more plastically deformed in the direction of reduced diameter in cross section than the inner layer 12A by applying a longitudinal tension F during manufacturing, the inner layer 12A is gripped. When sealing closely to two parallel planes, the outer layer 12B is not only soft and easy to adapt, but the sealing performance is improved, and the outer layer 12B is brought into close contact with the inner layer 12A by a manufacturing process that transforms the overall shape into a rectangle. Thus, it can be externally fitted without a gap, and the cross-sectional shape is stable and a highly accurate circular two-layer structure is obtained (see FIG. 10).

Further, the rectangular shape is rounded curved portion 3 is formed in the four corners, the radius of curvature R ₃ of the rounded curved portion 3 is set to 4 times to 25 times the outer diameter D ₁₂ of the outer member 12 Therefore, the curved portion 3 can be formed beautifully without causing excessive excessive plastic deformation in the curved portion 3 during manufacturing. In particular, the radius of curvature _{R 3,} preferably 5 times to 10 times the outer diameter _{D 12.}

  Moreover, according to the manufacturing method of the metal C-ring according to the present invention, the metal C-ring intermediate body 5 having a circular overall shape is manufactured, and then the curved portion forming receptacle 30 for forming the four corners of the rectangle is formed. 30, 31, 31 correspond to the inner peripheral side of the intermediate body 5, and the longitudinal bending force F is applied to the intermediate body 5 by the movement of the curved portion forming receivers 30, 30, 31, 31. In addition, since the overall shape is plastically deformed into a rectangular shape while forming the four corners having the curved portions 3 by the receivers 30, 30, 31, and 31, the overall shape currently manufactured in large quantities is circular. The metal C-ring can be used as it is, and the manufacturing equipment can be simplified. In addition, the quality of the metal C-ring is stable. In particular, it is a manufacturing method that does not require molds or jigs according to the size of the product, can be manufactured at low cost with simple equipment, and is also suitable for high-mix low-volume production. It is possible to respond quickly to requests.

  Further, the four rounded curved portion forming receptacles 30, 30, 31, 31 are attached to the first member 13 and the second member 14 which are reciprocally moved so as to be relatively close to and separated from each other. The short side 22 is formed by the two receiving members 30, 30; 31, 31 of the first member 13 and the second member 14, and the first member 13 and the second member 14 are moved by moving in the separating direction. Since the sides 21 and 21 are formed, one or both of the first member 13 and the second member 14 are reciprocated by a fluid cylinder, an electrically driven reciprocating actuator, etc. In addition, it is possible to easily realize multi-item and small-quantity production, particularly without requiring the skill of a conventional worker and without requiring a large mold or jig.

Moreover, when the above-mentioned curved portions 30 and 31 are made of a rotatable roller R ₀ , an excessive force can be prevented from acting locally when plastically deforming to the overall shape, and high quality. Metal C-ring can be manufactured smoothly in a container.

  Further, the joint portion 20 of the metal C ring intermediate body 5 is disposed between the two receivers 30 and 30 of the first member 13 or between the two receivers 31 and 31 of the second member 14. Thus, the tension F acting on the long side 21 by the movement of the first member 13 and the second member 14 in the separating direction is indirectly applied to the joint portion 20 on the short side 22 side via the support members 30, 30. Since it acted, the damage (crack generation etc.) at the time of manufacture of the joint part 20 can be prevented.

DESCRIPTION OF SYMBOLS 1 Metal C ring 3 Curved part 5 Metal C ring intermediate body 10 Opening part 11 Core material 12 Exterior material 12A Inner layer 12B Outer layer 13 1st member 14 2nd member 20 Seam part 21 Long side 22 Short side 30, 31 Earl curved part Forming receiver F Tension R ₀ Roller R ₃ Curvature radius D ₁₂ Outer diameter

Claims (8)

The overall shape is a rectangular shape having a long side (21) and a short side (22), and a seam portion (20) formed by welding, pressure welding or adhesion is disposed on the short side (22). Metal C-ring characterized by A rectangular shape having a long side (21) and a short side (22), which is composed of a core material (11) and a C-shaped exterior material (12) covering the core material (11). And the opening part (10) of the said exterior | packing material (12) is arrange | positioned along an outer peripheral side, and also the seam part (20) formed by welding of the said exterior | wrapping material (12) , pressure welding, or adhesion | attachment is provided. A metal C-ring arranged on the short side (22).   The exterior material (12) includes an inner layer (12A) and an outer layer (12B), and the metal material of the outer layer (12B) has a lower yield point than the metal material of the inner layer (12A), and is easily plastically deformed. In addition, the outer layer (12B) is more plastically deformed in the direction of diameter reduction of the cross section than the inner layer (12A) by applying a longitudinal tension (F) during the manufacture so that the overall shape becomes the rectangular shape. The metal C-ring according to claim 2, wherein the metal C-ring is configured to grip the inner layer (12A). The rectangular shape rounded bend region (3) is formed in the four corners, the radius of curvature (R ₃₎ of the rounded curved portion (3), said outer package outside diameter of (12) four times (D ₁₂₎ The metal C-ring of Claim 2 or 3 set to -25 times.   The metal C-ring intermediate (5) having a circular overall shape is manufactured, and then the curved portion forming receivers (30) (30) (31) (31) for forming the four corners of the rectangle are Corresponding to the inner peripheral side of the intermediate body (5), the longitudinal bending force (F) is applied to the intermediate body (5) by the movement of the curved portion forming receiver (30) (30) (31) (31). The metal C is characterized in that the overall shape is plastically deformed into a rectangular shape while forming the four corners having the curved portions (3) by the receivers (30) (30) (31) (31). Ring manufacturing method.   The four above-described curved portions forming receptacles (30), (30), (31), and (31) are two in the first member (13) and the second member (14) that reciprocate so as to be relatively close to each other. The short side (22) is formed by the two receiving members (30) (30); (31) (31) of the first member (13) and the second member (14). The metal C-ring manufacturing method according to claim 5, wherein the long sides (21) and (21) are formed by moving the first member (13) and the second member (14) in the separating direction. 7. The method of manufacturing a metal C-ring according to claim 6, wherein the rounded bent portion forming receiver (30) (31) is a rotatable roller ( _R0 ). Metal C ring intermediate body between two receivers (30) and (30) of the first member (13) or between two receivers (31) and (31) of the second member (14) The long side (21) is arranged by moving the first member (13) and the second member (14) in the separating direction by arranging the seam portion (20) formed by welding, pressure welding or adhesion in (5). The metal C according to claim 6 or 7, wherein a tension (F) acting on the seam indirectly acts on the seam portion (20) on the short side (22) side through the support (30) (30). Ring manufacturing method.

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