JP2014114941A - Manufacturing method of metal c ring - Google Patents

Abstract

A metal C-ring manufacturing method capable of manufacturing a good-quality metal C-ring having an opening inside without causing wrinkles or the like is provided.
In a method of manufacturing a metal C-ring having a C-shaped cross section that opens radially inward, a U-shaped peak that protrudes radially outward by plastic working at a width center portion 7 of a circular short cylindrical material. The bulging portion 3 of the mold is formed, and then the hem portion 4 of the bulging portion 3 is cut to separate the intermediate member having a U-shaped cross section that opens radially inward. The inner end portions are plastic processed so as to approach each other to form a C-shaped cross section.
[Selection] Figure 3

Description

  The present invention relates to a method for manufacturing a metal C ring.

Generally, in a metal C ring manufacturing method, both ends of a metal strip are connected by welding or the like, or a thin pipe is cut and manufactured from a circular short cylindrical material (also called a hoop material) (for example, , See Patent Document 1). That is, it is a method of gradually forming a cross-sectional shape into a C shape while sandwiching such a circular short cylindrical material between a pair of rolls (for example, see Patent Document 1).
By the way, the C-ring is a sealing material that seals (seals) two opposing planes, and has two types of openings facing the radially outward direction or the radially inward direction (for external pressure and for internal pressure). Is present.
FIG. 7 shows a manufacturing method for a metal C-ring 21 having a C-shaped cross section that opens radially outward, and the cross-section is gradually formed into a C-shape while sandwiching a circular short cylindrical material 20 between a pair of rolls. It is a way to go. In this method, as shown in FIG. 7, the diameter D ₁ of the both end portions of the final C-shaped cross section than the outer diameter D ₀ of the (indicated by two-dot chain line in FIG. 7) based on the circular short tube-shaped material 20 The circular short cylindrical material 20 is stretched in the circumferential direction. In this case, there is no particular problem in plastic working.

However, the case of producing a metal C-ring 23 with an opening 22 inwardly roll forming, as shown in FIG. 8, the diameter D ₂ of the opposite ends 24 of the C-shaped cross section is shown by a two-dot chain line (FIG. 8 ) smaller than the outer diameter D ₀ of the original circular short cylindrical material 20, subjected to compression plastic deformation in the circumferential direction. Since the circular short cylindrical material 20 is thin, in most cases, due to the compressive force in the circumferential direction, the end 24 is not uniformly compressed in the circumferential direction, but is locally recessed (due to buckling) and wrinkles are generated, There was a fatal defect that it was not realized as a seal product (fluid leakage occurred). That is, since the metal C-ring 23 is pressed against two parallel planes to exhibit sealing performance, the smoothness of the press-contact sealing region (Z) shown in FIG. 8 is extremely important. However, the above-mentioned local dent (wrinkle) generated in the end portion 24 is also generated in the press-contact sealing region Z, and there is a possibility that sufficient sealing performance (sealability) cannot be exhibited.

Japanese Patent Laid-Open No. 01-172682

  The problem to be solved is that when forming a metal C ring with an opening on the inside by roll forming, the end part or the press-contact sealing region is not uniformly compressed in the circumferential direction, but locally dents and wrinkles occur, The sealing performance is lowered and it is not established as a sealed product.

  Therefore, the manufacturing method of the metal C ring according to the present invention is a method of manufacturing a metal C ring having a C-shaped cross section that opens radially inwardly. Forming a U-shaped ridge-like bulge projecting outward, and then cutting the hem of the bulge to separate the U-shaped intermediate member that opens radially inward; In addition, the radial inner end portions of the intermediate member are plastically processed so as to approach each other to form a C-shaped cross section.

  According to the metal C-ring manufacturing method of the present invention, there is no step of compressing plastic deformation of the metal (material) in the manufacturing process, and therefore there is an opening on the inner side without causing wrinkles (due to buckling). A metal C-ring having a stable and excellent sealing performance can be manufactured. In addition, an inner opening type metal C ring capable of sealing an internal pressure with a lower clamping force than a conventional metal C ring can be manufactured.

It is a cross-sectional side view which shows the metal C-ring manufactured by one Embodiment of this invention. It is a principal part expanded end view which shows a circular short cylindrical raw material. It is a principal part expanded end view which shows a bulging part formation process. It is a principal part expansion end view which shows an intermediate member isolation | separation process. It is a principal part expansion end view which shows an inner end part approach process. It is a principal part expanded sectional view for an effect | action description while showing a modification. It is a cross-sectional side view which shows a prior art example. It is a cross-sectional side view which shows another prior art example.

FIG. 1 shows a metal C-ring 1 manufactured by the manufacturing method according to the present invention. This metal C-ring 1 has a C-shaped cross section having an opening 10 that opens radially inward. 1 consists of aluminum, stainless steel, steel, etc., for example. The outer diameter _{d 1} of the cross-section of the metal C-ring 1, for example, set to 5 mm to 7 mm. The external dimensions _{d 2} of the metal C-ring 1, for example, set to 500mm~ 700mm.

  Next, the manufacturing method of the metal C ring of one Embodiment of this invention is demonstrated. First, a U-shaped mountain projecting radially outward as shown in FIG. 3 by plastic working while maintaining the inner diameter dimension D at the width center portion 7 of the circular short cylindrical material 2 as shown in FIG. The bulging part 3 of the mold is formed (bulging part forming step). The circular short cylindrical material 2 is generally called a hoop material.

  Specifically, the bulging part forming step includes, for example, a method of forming with a pair of rolls (not shown) having a concavo-convex shape, a method of repeatedly forming a partial press, a tube hydroforming (a mold on the outside) By applying an internal pressure to the tube and keeping it along the mold).

The width dimension W ₁ (see FIG. 2) of the circular short cylindrical material 2 and the circumferential length dimension L ₀ (see FIG. 1) of the metal C ring 1 to be manufactured are set so as to satisfy W ₁ ≧ L _0. . In the case of W ₁ <L ₀ , a metal C ring cannot be manufactured.

  Next, as shown in FIG. 4, the hem portion 4 of the bulging portion 3 is cut to separate the intermediate member 5 having a U-shaped cross section that opens in the radial inward direction (intermediate member separation step). Specifically, the intermediate member separation step is, for example, by cutting with a saw, cutting with a laser, or the like.

  Next, as shown in FIGS. 1 and 5, the radial inner end 6 of the intermediate member 5 (see FIG. 4) is plastically processed so as to have a C-shaped cross section having an opening 10. (Inner end approaching step). Specifically, the inner end approaching step is, for example, by roll forming.

  The present invention can be changed in design, and may include a coil spring insertion step of inserting the coil spring 11 between the intermediate member separation step (FIG. 4) and the inner end approaching step (FIG. 5), for example. That is, the coil spring 11 (shown in FIG. 6) is housed in the U-shaped intermediate member 5 in FIG. 4, and then plastic working is performed so that the inner end portions 6 are close to each other, as shown in FIG. The metal C-ring 1 having a cross-sectional view can be produced freely.

  In the enlarged cross-sectional view shown in FIG. 6, the method of using the metal C-ring manufactured according to the present invention and its operation and effect will be described. The sealing material that forms a sealing action between two parallel planes 12 and 13 facing each other is described. The opening 10 opens in the radial inward direction (downward in FIG. 6). When the two planes 12 and 13 approach each other from the directions of the arrows Y and Y, in the cross section (substantially from the position of the opening 10). Upon receiving the pressure contact force F in the pressure contact sealing regions Z and Z (perpendicular to each other), the opening 10 is slightly closed and the cross section is slightly elliptical so that it has a compressive and elastic deformation to form a sealing action. . In addition, when the coil spring 11 is housed inside, the elastic reaction force against the pressing force F can be increased. According to the above-described manufacturing method of the present invention, the press contact sealing regions Z and Z are included from both end portions 14 and 14 forming the opening 10, and minute uneven portions such as wrinkles are generated on the entire outer peripheral surface of the metal C ring 1. In particular, the fluid sealability (sealing performance) is stable and excellent by using a smooth surface in which such minute uneven portions are not present in the press-contact sealing regions Z and Z. Or, compared with the conventional metal C-ring 23 of FIG. 8, it becomes possible to exhibit a sufficient sealing performance with a low tightening force, and in FIG. Power can be reduced. For example, it can be said that it is suitable when the material of the members forming the two planes 12 and 13 is fragile.

  As described above, the present invention is a method for manufacturing a metal C ring having a C-shaped cross section that opens radially inward. A protruding U-shaped bulged portion 3 is formed, and then the hem portion 4 of the bulged portion 3 is cut to separate the intermediate member 5 having a U-shaped cross section that opens radially inward. In addition, since the radial inner end 6 of the intermediate member 5 is plastically processed so as to approach each other, the cross section is C-shaped, so that there is no step of compressing the metal (material) in the manufacturing process (compression plastic deformation step). Therefore, it is possible to manufacture a high-quality metal C ring 1 (having an opening on the inside) without generating fine uneven portions such as wrinkles (due to buckling). Further, the inner opening type metal C ring 1 capable of sealing the internal pressure with a lower tightening force than the conventional metal C ring can be manufactured.

2 Circular short cylindrical material 3 Swelling part 4 Bottom part 5 Intermediate member 6 Radial inner end part 7 Width center part

Claims (1)

In the manufacturing method of a metal C-ring having a C-shaped cross section that opens radially inward,
A U-shaped ridge-shaped bulge portion (3) projecting radially outward is formed by plastic working at the width center portion (7) of the circular short cylindrical material (2), and then the bulge portion ( 3) The skirt (4) of 3) is cut to separate the intermediate member (5) having a U-shaped cross section that opens radially inward, and then the radial inner end (6) of the intermediate member (5) A metal C-ring manufacturing method, wherein the metal C-ring is plastically processed so as to approach each other to have a C-shaped cross section.

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