JPS5848263B2 - Method and device for forming a ring into a perfect circle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for forming a ring into a perfect circle by enlarging or shaping a ring material to obtain a perfect circle ring-shaped product with specified dimensions. .

Conventionally, in order to obtain a ring-shaped product by molding a ring material, a ring material 1 is placed on a core metal 3 and then pressed or hammered, as shown in FIGS. A ring-shaped product is obtained by rolling the ring between the crosshead 5 or the rolling anvil 2 attached to the block 5, reducing its thickness, expanding its diameter, and shaping it to a specified size.

In this process, the thickness of the ring material 1 is gradually reduced, and the processed amount moves in the circumferential direction of the ring material 1. Due to factors such as the width during forming, the moving direction of the processed portion becomes non-uniform, so that the ring material 1 is always shaped with distortion or a circular shape.

Furthermore, if we look in detail at the already formed part and the unformed part shown in FIG. There is.

For this reason, as shown in FIG. 4, a phenomenon occurs in which the material swings as indicated by arrow X when it is rolled down, which further promotes distortion or irregularity.

As the ring made of ring material 1 deforms in this way, it becomes difficult to clearly measure the specified dimensions, and as a result, the current situation is that workers rely on their intuition and experience to determine the dimensions. It is.

The result is a decrease in material yield, an increase in machining allowance, an increase in molding time, etc., which are major causes of high costs.

In order to overcome these drawbacks, the present invention aims to provide a circular correction mechanism on the left and right sides of the reduction anvil to improve the roundness of the ring and to obtain a ring-shaped product at low cost.

This will be explained based on FIGS. 5 to 11.

5 indicates a press crosshead or a hammer block, and 6 indicates an anvil mounted thereon.

A reduction anvil 2 is attached to the anvil stand 6, and straightening pieces 7, 7' are arranged on the left and right sides thereof.

The height h of the reduction anvil 2 can be changed by inserting a liner 8 depending on the specified dimensions of the ring.

In this case, separately prepared rolling anvils 2 of different heights may be used.

The width W of the correction piece 7 can also be changed by moving it laterally in accordance with the designated dimensions of the ring.

Figures 7 and 8 show the case where h1<h2 Wl:'W2, and only the height h of the rolling anvil 2 is changed without changing the width W between the straightening pieces 7 and 7'. Fig. 7 shows the case where the cross section is applied to a small diameter ring, and Fig. 8 shows the case where the cross section is applied to a large diameter ring.

In FIGS. 9 and 10, W1<W2 h1=h2, and the height h of the reduction anvil 2 remains unchanged, and the straightening pieces 7,
Fig. 9 shows a case where the width W between γ is changed, and Fig. 9 shows a case where this is applied to a small diameter ring, and Fig. 10 shows a case where this is applied to a large diameter ring.

a, a', a' indicate three points where the curvatures of the rolling anvil 2 and both straightening pieces 7, 7' and the ring-shaped product 1' match.

In each figure, the correction pieces 7 and 7' are shown as having a metal mold shape with a taper, but in short, the correction pieces 7 and 7' are formed at three points a, a', a'
Any material that can match the curvature of the material is sufficient, so it can be replaced with a roller or other shape.

When a ring-shaped product is hot- or warm-molded by this method, the ring material 1 with the hole drilled has a core metal 3 inserted into the hole, and both ends of the ring material 1 are supported by well-known hole expanding tables. Ru.

(The hole expander is marked 4 and 4' in Figures 1 and 2.
This is indicated by .

) Then, this ring material 1 is rolled down onto the core bar 3 using a rolling anvil 2 to form a certain shape.

During this time, the ring material 1 is fed in the circumferential direction by being rotationally driven by a large rolling force source (not shown).

The curvature of the straightening pieces 7, 7' of the roll anvil 2 with respect to the specified dimensions, that is, the curvature of the roll anvil 2 and both straightening pieces 7, 7 shown in FIG.
' or the three points a shown in Figures 7 to 10.
, a', the curvature of a' is determined in advance before the start of the precept,
Set them up as shown in each diagram.

Therefore, at the beginning of a certain form, the ring material 1 is rolled down only by the rolling anvil 2 placed in the center, and the straightening pieces 7,
7' usually does not touch this.

As the ring material 1 is sequentially expanded, the correction piece 7
, 7' begin to come into contact with each other, and as a result, the perfect circle is gradually corrected.

Finally, the reduction anvil 2 and both straightening pieces 7, 7' are attached to the ring-shaped product 1.
The same material has been formed into a perfect circle when it comes into contact with ' at three points a, a', and a'.

The above is an explanation of obtaining a perfectly circular ring-shaped product from the ring material 1, but as shown in Figure 11, the ring-shaped product 1', which has already been shaped to the specified dimensions, may When the product is deformed into an oval shape or the like, it can be corrected to the original perfectly circular ring-shaped product 1'.

In this case as well, while rotating the ring-shaped product 1', the reduction anvil 2 and the two straightening pieces 7, 7', which have been set in advance with the same curvature, are rotated.
By pressing down to three points a, a', and a' where the curvature matches that of the curvature, the molding is performed solely for the purpose of correction.

In this case, the principle is to shape the ring in a certain way without reducing its wall thickness or enlarging or changing its diameter.

In addition, when setting the initial curvatures of the rolling anvil 2 and both straightening pieces 7, γ, as shown in FIGS. 7 and 8, both straightening pieces 7, 7' are fixed and the width W is set. without changing (w1-w2), change the height h of the rolling anvil 2 (h1<
h2) As shown in FIGS. 9 and 10, the rolling anvil 2 is fixed and its height h remains unchanged (h1=h2), and both straightening pieces 7, 7'
This can also be done by changing the width W (w1<W2).

Further, both the reduction anvil 2 and both straightening pieces 7, 7' can be changed.

It has been experimentally confirmed that the amount of distortion or ellipse formed by the present invention is reduced to less than i compared to the conventional method, and that specified dimensions can be measured more accurately.

As can be seen from the above description, the present invention improves the material yield, and in other words, by reducing the amount of material brought in, the heating time for molded products and the heat treatment heating time can be shortened. This also eliminates the conventional process of correcting distortions or irregularities, shortening the molding time and process.

Furthermore, for products that require machining, the time required for machining is shortened, and it is easier to form perfect circles to specified dimensions.

[Brief explanation of the drawing]

Fig. 1 is a front view of the conventional device, Fig. 2 is a vertical cross-sectional view of Fig. 1, Fig. 3 is a cross-sectional view illustrating a certain state of the conventional device, and Fig. 4 is a process of forming the conventional device. 5 to 11 are cross-sectional views for explaining the present invention,
Figure 5 shows the main parts when a press or hammer is used, Figure 6 is a cross-sectional view taken along the line A-A', Figure 6 is a side view,
Figure 7 is a front view showing the precept state, Figures 8 to 10 are front views of main parts showing examples of adjustment of specified dimensions, and Figure 11
The figure is a front view showing round correction of a pre-formed ring-shaped product. 1... Ring material, 1'... Ring-shaped product, 2... Rolling anvil, 3... Core metal,
6...Anvil stand, 7,7'...Correcting piece.

Claims (1)

[Scope of Claims] 1. When shaping a ring material by hot or warm processing, a reduction anvil and straightening pieces provided on the left and right sides of the anvil are pre-aligned with a ring-shaped product of specified dimensions. The curvature is set to match the contact point, and the ring material placed on the core metal is rolled down using this rolling anvil.Then, the straightening pieces are used to correct distortions or circles formed on the ring material, and then the rolling anvil is used to A method of forming a ring into a perfect circle by continuing until both the straightening piece and the straightening piece match the curvature of the ring-shaped product with specified dimensions. 2. When determining the curvature of the rolling anvil and straightening piece that matches the contact point with a ring-shaped product of specified dimensions, fix the rolling anvil or straightening piece, and adjust the width (position) or height of the straightening piece or rolling anvil. A method for shaping a ring into a perfect circle according to claim 1, which is modified. 3. To correct distortions or circles in a ring-shaped product that has already been shaped to the specified size, use a reduction anvil and correction pieces placed on the left and right sides of the anvil to match the point of contact with the ring-shaped product of the specified size in advance. A method of forming a ring into a perfect circle by setting the curvature and forming it into a perfectly circular ring-shaped product of a predetermined size using the reduction anvil and right and left straightening pieces. 4. A reduction anvil is installed on an anvil stand to be attached to a press or a hammer, a straightening piece is attached to the left and right sides of the reduction anvil, and a core bar on which the ring material is fitted is provided below it, and the reduction anvil and A device that forms a ring into a perfect circle by matching the curvature of both correction pieces at the point of contact with a ring-shaped product of specified dimensions. 5. A device for shaping a ring into a perfect circle according to claim 4, in which the height of the reduction anvil and/or the width (position) of the correction piece can be adjusted.