JP2002210529A - Hot forming method for titanium alloy cylindrical parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot forming method for titanium alloy cylindrical parts in which the number of welding parts is reduced, and the number of hot formings per product is reduced. SOLUTION: Blanking of a plate 1 is performed in (a), a cylindrical parts 2 is formed by performing the welding 3 after the plate is formed in a cylindrical shape in (b), a sectional die holder 13 and the cylindrical parts 2 are pressed against a die 12 within a heating furnace 15 by a punch 10 in (c), and hot- formed at the temperature of 680-720 deg.C. After the hot forming, the completed cylindrical parts 4 is taken out as shown in (d). The sectional die holder 13 connects upper portions of eight split pieces by a ring, and fits lower portions thereof to a base in a radially mobile manner. When a wedge-like projection part 11 is inserted, each split piece is expanded outwardly to expand the cylindrical parts, and the cylindrical parts is hot-formed. Welding 3 may be performed only once.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of hot forming a cylindrical part made of a titanium alloy, and more particularly to a method of forming a cylindrical part having a step portion having a tapered diameter. The number of welding points is also reduced to significantly reduce the processing time.

[0002]

2. Description of the Related Art In recent years, titanium alloy parts have been widely used in fields where high heat resistance is required at high temperatures. Requires a lot of man-hours. In particular, it is difficult to integrally mold a cylindrical part having a tapered step part in the middle, it is necessary to have a divided structure, and the number of jigs to be used and the number of welding points are large, requiring considerable man-hours. is the current situation.

FIG. 6 is a view showing an example of a conventional hot forming method for a cylindrical part made of a titanium alloy. The part is cylindrical, tapered, and has a step portion whose diameter is reduced. Things. Processing is easy if it has a simple cylindrical shape. However, in the case of such a titanium alloy having a tapered portion in the middle, simple processing cannot be performed to obtain a cylindrical shape.

[0006] In FIG. 6, first, in FIG. In (b), this titanium alloy plate 8
0 is set in the heating furnace 15 on the die 82 on which a curved mold having a tapered shape is formed.
Press on 1. About 680 ° C to 720 ° C in the heating furnace 15
Is maintained at a high temperature. After being pressed by the punch 81 for a predetermined time, the plate 80 becomes one of cylindrical parts having a tapered step.
A 分割 split piece 83 is formed and taken out of the heating furnace 15.

[0005] Next, in (c), the divided piece 83 of the cylindrical part is trimmed to a regular size to form a regular part 8.
As shown in (d), the three divided pieces 84 are combined and welded 85 at three places, and finally the stress is removed by a welding strain relief jig to obtain a finished product.

[0006]

As described above, in the conventional hot forming method of a titanium alloy cylindrical component, a flat plate material is placed on a die in a heating furnace and pressed by a punch to form the cylindrical component. (1) Hot forming needs to be performed by the number of divided pieces. (2) It is necessary to weld a plurality of divided pieces after hot forming, and the number of welding locations increases. (3) A jig for welding and a welding distortion removing jig are required because there are many welding locations. Such (1) ~
Because of the problem (3), a long processing time is required, and some countermeasures have been desired.

Therefore, the present invention relates to a method for hot forming a cylindrical part made of a titanium alloy and having a tapered step in the middle thereof, wherein the hot forming only needs to be performed once per product and the number of welding points is reduced. Eliminates the need for welding work after hot forming,
An object of the present invention is to provide a hot forming method capable of reducing the number of jigs and significantly reducing a processing time.

[0008]

The present invention provides the following methods (1) and (2) in order to solve the above-mentioned problems.

(1) A hot forming method of a cylindrical part having a step portion whose diameter changes in a tapered shape in the middle of a cylinder made of a titanium alloy, comprising cutting a titanium alloy plate to a predetermined width and length. Bending the cut plate into a tubular shape and welding a seam to form a tubular molded product; placing the tubular molded product in a die having the same female mold as the outer shape of the cylindrical component; inside the tubular molded product Inserting and setting a split mold whose circumference can be enlarged; inserting the wedge-shaped pressing die into the split mold from above while the die after setting is heated to a high temperature in a heating furnace; A method for hot forming a cylindrical part made of titanium alloy, characterized in that the cylindrical shaped part is expanded by pressing and the cylindrical molded product is pressed against the female mold wall surface of the die to perform hot forming.

(2) Instead of moving the wedge-shaped pressing die, the wedge-shaped pressing die is fixed, and the die is moved from below to the wedge-shaped pressing die. A hot forming method of the titanium alloy cylindrical part described in the above.

In the hot forming method (1) of the present invention, first, a plate material of a titanium alloy is removed, a cylindrical molded product is pressed from the plate material, and the seam is joined by welding. This cylindrical molded product is placed in a heating furnace, placed in a female mold of a die, and further formed into a cylindrical shape with a plurality of divided pieces in the cylindrical molded product. Is done.
The die on which the cylindrical molded product and the split mold are set is heated to a high temperature in a heating furnace, for example, at a temperature of 680 ° C. to 720 ° C., and a wedge-shaped press die is inserted into the split mold from above the die, and The plurality of divided pieces are expanded outward. When the plurality of divided pieces are enlarged, the outer cylindrical molded product is pushed outward and pressed against the inner wall surface of the female die of the die, and is hot-formed.

According to the hot forming method of the present invention, welding need only be performed once before being put into a heating furnace, so that welding at many places is unnecessary as in the prior art, and the number of jigs is small. And the processing time is significantly reduced.

In (2) of the present invention, instead of moving the wedge-shaped pressing die, the die is fixed and the die is moved. Therefore, the same effect as the above-mentioned invention (1) can be obtained. The range of application for implementing the molding method is expanded.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a diagram showing steps of a method for hot forming a titanium alloy cylindrical component according to a first embodiment of the present invention. In the figure, in (a), a material 1 is cut by cutting a plate material 1 made of a titanium alloy. (B)
In (2), this is bent into a circular shape and subjected to welding 3 to produce a cylindrical component 2 having a tapered shape.

In (c), the cylindrical part 2 is placed in a heating furnace 15.
Then, a split jig 13 is set inside the cylindrical part 2 in the female opening of the die 12. As will be described later, the split jig 13 has a structure in which eight split pieces are combined into a cylindrical shape, and each split piece is configured to be expandable in the radial direction from the center, and the outer shape has a tapered shape of the final product. The shape is equal to the inner diameter of the cylindrical part. When the split jig 13 is set, the inside of the heating furnace 15 is heated to a temperature of 680 ° C. to 72 ° C.
Maintain at 0 ° C.

Next, the punch 10 is lowered in this heated state, and the wedge-shaped projection 11 of the punch 10 is
The split part of the split jig 13 is pushed outward from the center by the wedge-shaped projection 11 to spread the cylindrical part 2 in the female die of the die 12. The cylindrical part 2 is a punch 10
It is pushed in the radial direction by the projections 11 and extends in the circumferential direction and expands along the mold of the die 12 to be hot-formed. Split jig 13
As described later, each of the eight divided pieces is assembled in a cylindrical shape, the upper part is connected by a ring, it can be moved in the radial direction and can be expanded, and the lower part is the same as the upper part along the groove on the base surface As described above, the structure can be moved in the radial direction and can be easily expanded in the die 12.

The cylindrical part 2 hot-formed in the heating furnace 15
Is a completed cylindrical part 14 having a tapered step portion in the middle as shown in FIG. According to the hot forming method of the titanium alloy cylindrical component of the first embodiment, hot forming has conventionally been required several times for one product, but only once is required. In addition, the conventional welding work is a production by a divided structure, and conventionally three or four places of welding were necessary, but only one time was necessary, and the conventional welding was performed after hot forming. In the present invention, welding after hot forming is not required, so that a jig for removing welding stress is not required.

FIGS. 2A and 2B show the split jig 13 described above, wherein FIG. 2A is a plan view of an upper ring, FIG. 2B is a side view of the entire split jig, and FIG. AA arrow view,
(D) is a BB arrow view in (b). (A) shows the ring 20 on the upper surface, and the ring 20 is provided with eight elongated holes 21 extending in the center direction equally, and forms bolt holes for fixing eight divided pieces.

In FIG. 2 (b), the split jig 13 is composed of an upper ring 20 and eight divided pieces, each of which forms a flange 23 at the upper part. Are connected to the ring 20 by bolts 26, each upper part of which is movable in the radial direction along the elongated hole 21 of the ring 20. Further, a projection 27 is provided at the lower end of each divided piece, and can be moved in the radial direction in a groove of the floor on the base surface as described later. The outer shape of each divided piece is the same as that of the completed cylindrical part 14, and has a tapered step.

(C) is a view of the bottom taken along the line AA. Each divided piece is formed with a flange 25 directed toward the center. Each flange 25 is provided with a projection 27, and each projection is a base. Can be moved in the radial direction along the inside of the groove provided on the floor surface.

FIG. 3D is a view taken in the direction of the arrows BB, and shows the upper flange of each divided piece. A radially oriented flange 23 is formed at the top of each split piece, and a bolt hole 24 is drilled at each flange 23 so that the long hole 2 of the upper ring 20 can be formed.
1 is connected to the ring 20 by bolts.

FIGS. 3A and 3B show the detailed structure of each part of the split mold jig. FIG. 3A is a partial side view showing the connection between the upper ring and each divided piece, and FIG. 3B is a partial side view showing the lower structure. Figure,
(C) is a CC cross-sectional view in (b), and (d) is a perspective view showing an upper part of the divided piece. In (a), the ring 20 is provided with a long hole 21 in the form of a loose hole, and the flanges 23 of the divided pieces are connected via the long holes of the ring 20 by bolts 26, so that the divided pieces are placed on the ring 20. It is movable along the elongated hole 21 in the radial direction.

In (b), an inwardly facing flange 25 is formed at the lower end of the divided piece, and a projection 27 is provided on the flange 25. The projection 27 has a radius along a groove 30 provided on the floor surface. It is installed so that it can move in the direction. (C)
5B is a cross-sectional view taken along the line CC of FIG. 5B, in which an elongated groove 30 facing the center is formed in the floor 31, and a projection 27 provided on the flange 25 of the divided piece is inserted into the groove 30. ,
It is installed so as to be movable in the radial direction.

(D) shows the upper part of the split piece, and the split piece is formed with a flange 23 facing inward, and the flange 23 is provided with a bolt hole 24 so as to be connected to the ring 20 by a bolt. . Each of the divided pieces divided into eight parts by the structure of the split jig can be easily moved in the upper part and the lower part toward the outside in the radial direction and can be enlarged.

FIG. 4 shows a method of hot forming a cylindrical part made of a titanium alloy according to a second embodiment of the present invention, in which a punch is fixed and a die is moved up and down. In the first embodiment shown in FIG. 1, the punch 10 is moved up and down to press the split jig 13 and the cylindrical part 2 set on the die 12. However, in the second embodiment, And the punch 10 is fixed on the upper part, and the die 12 on which the split jig 13 and the cylindrical part 2 are set is set.
Is moved up and down by the cylinder 40.
Other configurations are the same as those shown in FIGS. Even with such a configuration, the same operation and effect as those of the first embodiment can be obtained.

That is, in FIG. 4 (a), the punch 10 is fixed, and the cylinder 40 is actuated to raise the die 12 and join it to the wedge-shaped projection 11 of the punch 10.
Hot pressing is performed by pressing, and when hot forming is completed, the cylinder 40 is lowered to release the punch 10 and the die 12 as shown in FIG.

FIG. 5 is a view showing an example of a product using the completed cylindrical part 14 formed by the hot forming method according to the first and second embodiments described above. FIG. FIG. 2B is a perspective view of the bearing cover incorporated therein, and FIG. 2B is a cross-sectional view of a bearing portion of the engine to which the bearing cover is attached.

As shown in (a), an upper part 61 and a lower part 62 of a titanium alloy are joined to the finished cylindrical part 14 manufactured by the hot forming method of the present invention by welding, as shown in (b). Is mounted as a cover that covers the periphery of the bearing 72 of the shaft 71 in the engine body 70, and is used to protect the bearing in a high-temperature atmosphere. Thus, if the hot forming method of the present invention is applied to the production of a cylindrical component having a cylindrical and tapered step portion requiring a titanium alloy,
Only one welding point is required, hot forming only needs to be performed once per product, the number of jigs for processing can be reduced, and it is effective for the production of titanium alloy cylindrical parts. It is a means.

[0029]

According to the present invention, there is provided a method for hot forming a cylindrical part made of a titanium alloy, comprising: (1) a method of hot forming a cylindrical part made of a titanium alloy and having a step portion whose diameter changes in a tapered shape in the middle of the cylinder. Cutting a titanium alloy plate into a predetermined width and length; bending the cut plate into a cylindrical shape and welding a seam to form a cylindrical molded product; a female mold having the same outer shape as the cylindrical component The cylindrical molded article is put into a die having: a split mold whose circumference can be expanded is inserted and set inside the cylindrical molded article; and the die after setting is heated to a high temperature in a heating furnace. It is characterized in that a wedge-shaped pressing die is inserted into the split die from above, and the split die is pressed to expand the die, and the cylindrical molded product is pressed against the female mold wall surface to perform hot forming.

According to the above-mentioned hot forming method, welding needs to be performed only once before being put into a heating furnace, so that welding at many places is unnecessary as in the conventional case, the number of jigs is reduced, and the processing time is remarkably reduced. Be shorter.

In (2) of the present invention, instead of moving the wedge-shaped pressing die, the die is fixed and the die is moved, so that the same effect as the above-mentioned invention (1) is obtained. The range of application for implementing the molding method is expanded.

[Brief description of the drawings]

1A and 1B show a method for hot forming a titanium alloy cylindrical part according to a first embodiment of the present invention, wherein FIG. 1A is a plan view of a plate material, FIG. 1B is a perspective view of the cylindrical part, and FIG. () Is a configuration diagram of hot forming in a heating furnace, and (d) is a perspective view of a completed cylindrical component.

FIGS. 2A and 2B show a split jig used in the hot forming method according to the first embodiment of the present invention, wherein FIG. 2A is a plan view showing an upper ring, FIG. () Is a view on arrow AA in (b), and (d) is a view on arrow BB in (b).

FIGS. 3A and 3B show a detail of a split jig according to the first embodiment of the present invention, wherein FIG.
(B) is a partial side view of the lower part, and (c) is C in (b).
FIG. 3C is a sectional view, and FIG. 4D is a partial perspective view of a divided piece.

4A and 4B show a hot forming method of a titanium alloy cylindrical part according to a second embodiment of the present invention, wherein FIG. 4A is a cross-sectional view in which a die is raised, and FIG. FIG.

FIG. 5 shows an application example of a cylindrical component manufactured according to the present invention, wherein (a) is a perspective view of an engine bearing cover,
FIG. 2B is a cross-sectional view of the engine bearing unit to which the bearing cover is attached.

6 (a) is a plan view of a sheet material, FIG. 6 (b) is a cross-sectional view of a punch and die of hot forming, and FIG. 6 (c) is a hot working method of a conventional titanium alloy cylindrical part. FIG. 4D is a perspective view of the divided part after molding, FIG. 4D is a perspective view of the divided part after performing a precise trim processing, and FIG. 4E is a perspective view of the cylindrical part after completion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate material 2 Cylindrical part 3 Welding 10 Punch 11 Wedge type protrusion 12 Die 13 Split mold jig 14 Complete cylindrical part 20 Ring 21 Long hole 22 Split type 23,25 Flange 24 Bolt hole 26 Bolt 27 Projection 30 Groove 31 Floor 40 Cylinder

Claims (2)

[Claims] 1. A method for hot-forming a cylindrical component having a step portion whose diameter changes in a tapered shape in the middle of a cylinder made of a titanium alloy, comprising cutting a titanium alloy plate to a predetermined width and length; The cut plate is bent into a tubular shape to weld a seam to form a tubular molded product; the tubular molded product is placed in a die having the same female shape as the outer shape of the cylindrical component; into the tubular molded product Inserting and setting a split mold whose circumference can be expanded; inserting the wedge-shaped pressing die into the split mold from above while pressing the die after setting is heated to a high temperature in a heating furnace, and pressing the split mold A hot forming method for a titanium alloy cylindrical part, characterized in that the cylindrical formed part is enlarged and pressed against the female mold wall surface of the die to perform hot forming. 2. The wedge-shaped press die is fixed, and the die is moved from below toward the wedge-shaped press die instead of moving the wedge-shaped press die. Hot forming method of cylindrical parts made of titanium alloy.