JP3565462B2 - Ring expanding core and ring expanding method using the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ring-expansion core used for expanding a ring-shaped object to be expanded formed of aluminum or an aluminum alloy (hereinafter, simply referred to as an aluminum alloy or the like) and the ring-expansion core. The present invention relates to a ring expanding method for expanding the diameter of a ring-shaped object to be expanded by using the method.
[0002]
[Prior art]
Conventionally, as a method of expanding the diameter of a ring-shaped expanded body formed of an aluminum alloy or the like, a ring-shaped expanded body is arranged around the outer periphery of a cylindrical ring-shaped expanding core, and the ring-shaped expanded body is expanded. A method is known in which a body is rotated around a core for enlarging while being compressed by a press and a core for ring enlarging, thereby expanding the diameter of the ring-shaped enlarged body.
[0003]
In such a ring expanding method, when the rate of expansion of the ring-shaped expanded object may be small, only one ring-expanding core may be used. When it is necessary to increase the ratio of the diameter expansion, use of only one ring-expansion core metal causes the ring-expansion core to relatively expand when the ring-shaped diameter-expanded body is expanded to some extent. Because the radius of curvature of the outer peripheral surface of the ring becomes small, it is not possible to increase the rotation pitch when rotating the ring-shaped expanded body around the ring-expanding core metal, thereby deteriorating work efficiency. In addition, there is a problem that the roundness of the ring-shaped expanded body is deteriorated.
[0004]
Therefore, conventionally, a plurality of cylindrical or semi-cylindrical ring expanding cores having different radii of curvature are prepared, and when the expanding of the ring-shaped expanded body has progressed to a certain extent, the radius of curvature is sequentially increased. The ring-shaped enlarged-diameter object has been finished into a ring of a predetermined diameter by replacing it with a large ring-diameter core.
[0005]
[Problems to be solved by the invention]
However, the use of a plurality of cylindrical or semi-cylindrical ring expanding cores having different radii of curvature as described above increases the manufacturing cost of the core and also requires space for placing them. There was a problem. Also, when the core metal becomes large, there is a problem that a large heavy machine or a crane is required for the replacement work, and the replacement work takes a long time. Furthermore, since the ring-shaped expanded body cools when the core is replaced, the ring-shaped expanded body must be reheated every time the core is replaced, which is troublesome. There was a problem.
[0006]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention provides a ring-expanding core and a ring-expanding method using the ring-expanding core, which solve the above problems.
[0007]
The ring-expanding metal core according to the present invention is arranged such that a ring-shaped expanding object is arranged on the outer periphery of the ring-expanding metal core, and the ring-shaped expanding object is compressed by a press and a ring-expanding core metal. While rotating around the core for expanding the diameter, in the core for expanding the ring used to expand the diameter of the ring-shaped expanded body by this, the core for expanding the ring, in the circumferential direction, it is characterized in that is obtained by forming a plurality of curved surfaces having different radii of curvature (claim 1).
[0008]
Further, in the ring expanding method according to the present invention, a ring-shaped expanded body is arranged on the outer periphery of a ring-expanding core, and the ring-shaped expanded body is compressed by a press and a ring-expanding core. In the ring expanding method in which the ring-shaped expanded body is rotated by rotating the expanded metal around the expanded metal core, a plurality of rings having different curvature radii in the circumferential direction are used as the expanded ring metal. When the ring-shaped expanded body is compressed and expanded with a press and a ring-expanding core using a ring-expanding core having the curved surface formed, a curved surface having a small radius of curvature has a large radius of curvature. A ring expanding method characterized in that the curved surfaces are sequentially opposed to the press side in the order of the curved surfaces (claim 2).
[0009]
By forming a plurality of curved surfaces having different radii of curvature in the circumferential direction of the ring expanding core, a plurality of ring expanding cores having different radii of curvature can be formed by one ring expanding core. The same operation as in the case of using can be achieved. That is, when the ring-shaped expanded body is compressed and expanded by the press and the ring-expanding core, first, the curved surface having the smallest radius of curvature is fixed to face the press, and in this state, the ring-shaped expanded body is fixed. The expanded body is rotated around a ring expanding core while being compressed by a press and a curved surface having a small radius of curvature, thereby expanding the ring-shaped expanded body to a certain value. After the diameter is expanded to a certain value, the curved surface having the second smallest radius of curvature is fixed to face the press, and the ring-shaped expanded body is expanded to a certain value in the same manner as described above. Thereafter, the ring-shaped expanded member can be finished into a ring having a predetermined diameter by sequentially performing the expanding operation in the same manner.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIGS. 1A and 1B show an embodiment of a core for expanding a ring according to the present invention. The core A for expanding a ring has different radii of curvature in a circumferential direction. Four curved surfaces 1, 2, 3, 4 are formed. The magnitude of the radius of curvature satisfies R ₁ <R ₂ <R ₃ <R ₄ . The magnitude of the radius of curvature is appropriately selected according to the expanding ratio of the ring-shaped expanded body to be expanded. In addition, the length L of the curved surfaces 1, 2, 3, and 4 is also appropriately selected, and this length can be the same as the length of the press at the maximum.
[0011]
The number of curved surfaces having different radii of curvature in the circumferential direction is not limited to four, but may be six, eight, ten, twelve, or the like. For example, FIG. 2 shows a ring expanding core metal having six curved surfaces, and the radius of curvature of the six curved surfaces is R <1.4R <1.8R <2.2R <2.6R. <3.0R.
[0012]
When forming curved surfaces having different radii of curvature in the circumferential direction as described above, it is preferable that curved surfaces having different radii of curvature in the circumferential direction are connected by a smooth taper, and that the curvature radii are opposite to each other from the balance. It is preferable to arrange a close curved surface.
[0013]
Next, a case where the ring-shaped expanded body is expanded by using the ring-expanding core metal having a plurality of curved surfaces having different curvature radii in the circumferential direction as described above will be described.
As shown in FIG. 3, the ring expanding core metal A is formed with four curved surfaces having different radii of curvature R ₁ <R ₂ <R ₃ <R ₄ in the circumferential direction. With the ring-shaped enlarged-diameter object B arranged on the outer periphery of the ring-expansion core A, both ends of the ring-expansion core A are fixed to the core base C. The time of the plurality of curved surfaces of the core metal A ring diameter, fixed toward the most curvature curved surface R ₁ having a small radius of the press D side.
[0014]
Then compressing the ring-shaped object to be enlarged body B with the best curvature curved surface R ₁ having a small radius of the press D and ring diameter expanding core metal A. This compression work is performed while rotating the ring-shaped enlarged-diameter object B around the ring-expansion core metal A. Thereby, the diameter of the ring-shaped expanded body B is expanded to a certain size.
[0015]
Next, the core A for ring expansion is rotated to fix the curved surface R2 having the _second smallest radius of curvature toward the press D side. Again ring-shaped object to be enlarged body B in this state is compressed between the curved surface R ₂ press D and ring diameter expanding core metal A. This compression work is performed while rotating the ring-shaped enlarged-diameter object B around the ring-expansion core metal A. Thus, the diameter of the ring-shaped expanded body B is further expanded.
[0016]
Hereinafter similarly curved R ₃ and curved surface R ₄ sequentially toward the press D side sequentially compress the ring-shaped object to be enlarged body B at each of these curved surfaces R ₃ · R ₄ and press D. Thus, the diameter of the ring-shaped enlarged body is expanded to a predetermined size, and a ring having a desired size is formed.
[0017]
【Example】
Four curved surfaces having radii of curvature of 450 mm, 650 mm, 850 mm, and 1050 mm were formed in the circumferential direction to form the core metal for ring expansion according to the present invention.
Using this cored bar, a ring-shaped expanded body made of an aluminum alloy having an inner diameter of 980 mm was finished into a ring whose final product had an inner diameter of 2200 mm.
At this time, the 450 mm curved surface was first fixed toward the press side, and the inner diameter was expanded to 1390 mm using the curved surface. Next, the 650 mm curved surface was fixed toward the press side, and the inner diameter was expanded to 1750 mm using the curved surface. Then, a 850 mm curved surface was fixed toward the press side, and the inner diameter was increased to 2000 mm using the curved surface. Finally, the 1050 mm curved surface was fixed toward the press side, and the inner diameter was expanded to 2200 mm using the curved surface. In the course of the diameter expanding operation, the ring-shaped expanded member was not reheated.
[0018]
On the other hand, according to the conventional method, four ring-expansion cores having curvature radii of 450 mm, 650 mm, 850 mm, and 1050 mm are separately manufactured, and this is used as an aluminum alloy ring-shaped enlarged object. In order to change the aluminum ring-shaped expanded body having an inner diameter of 980 mm into a ring having an inner diameter of 2200 mm. Further, in the conventional method, it is necessary to reheat the ring-shaped expanded body every time the core is replaced.
[0019]
In the present invention, not only one ring-expansion core metal having a plurality of curved surfaces having different curvature radii in the circumferential direction but also a plurality of ring-expansion core metals are used, and the ring-shaped Needless to say, the diameter of the expanded body may be expanded.
[0020]
【The invention's effect】
As described above, the ring-expansion core metal according to the present invention has a plurality of curved surfaces having different radii of curvature in the circumferential direction. The same operation as the core metal can be performed. Therefore, since the number of cored bars can be reduced, there is an effect that the manufacturing cost of the cored bars is reduced and the space for placing them is reduced.
[0021]
Further, according to the ring expanding method according to the present invention, the work of replacing the core metal can be eliminated or greatly reduced, and the operation of changing the curved surface of the core metal can be performed in a short time. Therefore, not only can the working time required for the diameter expansion be reduced, but also the work of changing the curved surface of the cored bar can be performed in a short time, so that there is no need to reheat the ring-shaped expanded body. There is.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a core for expanding a ring of the present invention, in which (A) is a sectional view and (B) is a side view.
FIG. 2 is a cross-sectional view showing another embodiment of the core for expanding the diameter of the ring of the present invention.
FIG. 3 is an explanatory view showing an implementation state of the ring expanding method of the present invention.
[Explanation of symbols]
A Ring expanding core B Ring-shaped expanded body C Core expanding base D Press ₁ , ₂ , ₃ , 4 Curved surfaces R ₁ , R ₂ , R ₃ , R ₄ Size of radius of curvature

Claims (2)

A ring-shaped expanded body is arranged on the outer periphery of the ring-expanding core, and the ring-shaped expanded body is rotated around the diameter-expanding core while being compressed by a press and a ring-expanding core. Accordingly, in the ring-expansion core used for expanding the ring-shaped enlarged-diameter object, the ring-expansion core has circumferentially formed a plurality of curved surfaces having different radii of curvature. A core metal for expanding the diameter of a ring. A ring-shaped expanded body is arranged on the outer periphery of the ring-expanding core, and the ring-shaped expanded body is rotated around the diameter-expanding core while being compressed by a press and a ring-expanding core. In the ring expanding method in which the ring-shaped expanded body is expanded by this, a ring expanding core having a plurality of curved surfaces having different radii of curvature in a circumferential direction as the ring expanding core. When expanding the ring-shaped expanded body by compressing it with a press and a ring-expansion core metal, use a A ring expanding method characterized by being opposed to each other.

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