JP4076102B2 - Sheet metal thickening press method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet metal thickening press method in which a thick portion is formed in a part of a sheet metal by press working.
[0002]
[Prior art]
For example, FIG. 13 shows a pulley 50 that is a transmission component of an automobile. The pulley 50 is a nut that is inserted into a screw portion 51a formed at the end of a rotating shaft 51 and screwed to the screw portion 51a. It is attached to the end of the rotating shaft 51 by 52.
[0003]
By the way, since the tightening portion 50a of the pulley 50 is required to have higher strength than other portions, the tightening portion 50a needs to be formed thick.
[0004]
Thus, as a method of manufacturing a part such as a pulley having a thick part in such a part, as shown in FIG. 14, after drawing into a desired shape with a thick plate 60, unnecessary parts are formed by machining. FIG. 15B shows a method of cutting (a hatched portion in the figure), crushing the end face of the member 70 formed into a predetermined shape by upsetting as shown in FIG. As shown, there is a method of locally forming the thick portion 70a (thickening method).
[0005]
[Problems to be solved by the invention]
However, the method shown in FIG. 14 requires a great number of man-hours for machining, and there is a problem that the product cost increases due to the waste of material, and the method shown in FIG. 15 (thickening method) shows the same figure. As shown in (b), since a fold defect P due to buckling occurs at the base of the thick portion 70a, it is necessary to remove that portion by machining, which increases the number of processing steps and the associated cost increase. There was an inevitable problem.
[0006]
The present invention has been made in view of the above problems, and the purpose of the processing is that of a sheet metal that can form a thick part without folding defects in a part of the sheet metal only by pressing without requiring machining. The purpose is to provide a thickening press method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a preliminary step of obtaining an intermediate member having a truncated cone-shaped inclined flange portion by bending or drawing or burring a sheet metal material,
A part of the outer peripheral surface of the inclined flange portion of the intermediate material obtained by the preliminary process is plated by a die having a die having a truncated cone-shaped concave portion and a punch having a truncated cone-shaped convex portion. Crushing in the direction of decreasing thickness, surplus generated by crushing, into a ring-shaped space portion formed between the intermediate material and the mold, respectively , within the thickness range of the intermediate material A thickening step of forming a thick portion in a part of the intermediate material by flowing;
Through this process, a part of the sheet metal is thickened.
[0008]
Therefore, according to the present invention, in the thickening process, a part of the outer peripheral surface of the inclined flange portion is crushed in the direction in which the plate thickness decreases, and the surplus generated by the crushing flows within the thickness range of the sheet metal material. As a result, a thick part is formed in a part of the sheet metal, so that there is no fold defect in the thick part as in the upsetting process. A thick part free of folding defects can be formed in a part of the sheet metal only by processing, and the number of processing steps can be reduced and the cost can be reduced.
[0009]
Moreover, according to this invention, a thick part can be formed not only in the end surface of a sheet metal raw material but in arbitrary positions like an upsetting process.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0011]
1 to 4 are cross-sectional views for explaining a preliminary process in the method of the present invention.
[0012]
In the construction method of the present invention, a drawing process using the upper die 1 and the lower die 2 and the punch 3 shown in FIG. 2 using a disk-shaped sheet metal material W ₀ having a thickness t and a diameter φD as shown in FIG. after obtaining the intermediate member W ₁ performs, by cutting the upper surface of the intermediate material W _1, or circular hole W _a at the center in the thickness t, the diameter φD as shown in FIG. 1 (b) A ring-shaped sheet metal material W _{0 having} 'is used to perform burring with the upper die 11, the lower die 12 and the burring punch 13 shown in FIG. An intermediate material W ₂ having a flange portion W _b is obtained.
[0013]
In the drawing shown in FIG. 2, by determining the number of drawing operations with an appropriate drawing ratio, an intermediate portion having a truncated cone-shaped inclined flange portion W _b having a surplus necessary for the target thickening molding. it is possible to manufacture a wood W _2. In this case, even with a small inner diameter, it is possible to increase the height h of the inclined flange portion W _b.
[0014]
Further, in the burring shown in FIG. 3, the height h of the inclined flange portion W _b of the intermediate member W ₂ frustoconical for hole expansion ratio with the sheet metal material W ₀ 'is limited, necessary for the thickening The surplus meat is also limited.
[0015]
Therefore, burring processing is adopted as a preliminary process when an intermediate material W ₂ having a large inner diameter is required, and drawing processing is preliminary when a small inner diameter but a high height h of the inclined flange portion W _b is required. Adopt as a process.
[0016]
Next, it is practiced thickened process using a press apparatus shown in FIGS. 5 to 7 with respect to the intermediate member W ₂ shown in Fig. 4 obtained as described above, shown in FIG. 9 by the thickening step An intermediate material W ₃ having a thick portion W _d in a part is obtained.
[0017]
Here, the structure of the press apparatus provided for the thickening step will be described with reference to FIGS. 5-7 is sectional drawing of the principal part of the press apparatus provided to a thickening process.
[0018]
5 to 7 includes an upper die 21 and a lower die 22. In the lower die 22, 23 is a die set. On the die set 23, a punch holder 24 and a die ring 25 are provided. They are fixed one after another. A punch 26 is inserted and held in a circular hole 25a penetrating in the center of the die ring 25, and a ring-shaped stepped recess having a predetermined depth and diameter around the circular hole 25a on the upper surface of the die ring 25. 25b is formed.
[0019]
By the way, the upper end portion of the punch 26 constitutes a truncated cone-shaped convex portion 26 a, and the lower end of the punch 26 is attached to the punch holder 24 by a bolt 27.
[0020]
An intermediate material W ₃ (see FIG. 7 and FIG. 9) after molding is removed from the lower die 22 in a plurality of circular holes 28a penetrating the die ring 25, punch holder 24 and die set 23. Ejector pins 28 for insertion are respectively inserted. The upper ends of the ejector pins 28, as illustrated in the flange portion W _c of the intermediate material W ₂ (W ₃₎ abuts the lower end is attached to the cushion plate 29 in the lower die set 23. A die cushion 30 is connected under the cushion plate 29.
[0021]
On the other hand, the upper die 21 includes a die set 31 and a cylindrical die 32 attached to the die set 31, and the bottom of the die 32 is a truncated cone of the punch 26 constituting the lower die 22. A frustoconical concave portion 32a corresponding to the convex portion 26a is formed.
[0022]
Reference numeral 33 denotes a stripper constituting the upper die 21. The die 32 is fitted in a circular hole 33a penetrating in the center of the upper die 21 so as to be slidable up and down. A plurality of springs 34 are interposed between the stripper 33 and the die set 31. Around the circular hole 33 a on the bottom surface of the stripper 33, the die ring 25 constituting the lower die 22 is formed. A ring-shaped stepped convex portion 33b to be fitted into a stepped concave portion 25b formed on the upper surface is integrally formed.
[0023]
Next, the thickness increasing process implemented using the press apparatus which has the above structure is demonstrated based on FIGS. FIG. 8 is an enlarged detail view of part A in FIG.
[0024]
In the set state shown in FIG. 5, the upper die 21 is positioned above the lower die 22 so as to be separated from the upper die 21. In the lower die 22, the ejector pin 28 is located at the upper limit position via the cushion plate 29 and the die cushion 30. The intermediate material W ₂ is positioned and set so as to slightly contact the peripheral surface (step wall) 25c of the step recess 25b of the die ring 25.
[0025]
Thus, when the upper die 21 is lowered by the driving means (not shown) from the set state shown in FIG. 5, the stripper 33 is placed on the upper surfaces of the intermediate material W ₂ and the die ring 25 of the lower die 22 as shown in FIG. abuts the flange portion W which Dantotsu portion 33b projecting from the bottom of the stripper 33 excluding an inclined flange portion W _b of the intermediate member W ₂ fitted into stepped recess 25b formed on the upper surface of the die ring 25 the _c is pressed to the die-ring 25 side, the ejector pins 28 and the cushion plate 29 and the die cushion 30 is the rear surface and the die ring 25 of the flange portion W _c of the intermediate material W ₂ as shown in the lower die 22 along with this It descends until the stepped recess 25b comes into contact.
[0026]
When the upper die 21 is further lowered in the above state, the die 32 is guided and lowered by the circular hole 33a of the stripper 33, and the spring 34 interposed between the die set 31 and the stripper 33 of the upper die 21 is moved. The reaction force is increased by being compressed.
[0027]
And Thus, the die 32 of the upper mold 21 is lowered as described above, part of the outer circumferential surface of the inclined flange portion W _b of the intermediate member W ₂ is the slope of the frustoconical recess 32a of the die 32 along with this The surplus portion of the portion a shown in FIG. 8 generated by the crushing is formed between the stripper 33, the die 32, and the intermediate material W ₂ . Part of the intermediate material W ₂ flows into the ring-shaped space c (see FIG. 8) formed between the ring-shaped space b (see FIG. 8), the die ring 25, the punch 26, and the intermediate material W ₂ . Is increased. As a result, the intermediate member W ₃ in which thick portion W _d is partially formed around the tapered hole W _e narrowed down upward as shown in FIG. 9 is obtained.
[0028]
The intermediate material W ₃ shown in FIG. 9 obtained through the burring process or the drawing process as the preliminary process described above is cut off along the cut line c shown in the drawing by the punching process, thereby removing the intermediate material W ₃ . As shown in FIG. 10, an intermediate material W ₄ in which a thick portion W _g is formed around the central circular hole W _f is obtained.
[0029]
Thus, in the intermediate material W ₄ shown in FIG. 10, the flange portion W _c excluding the thick portion W _g is drawn into a shape as shown in FIG. 11 and FIG. Product 10 is obtained.
[0030]
As described above, in the thickened pressing method according to the present invention, crushed part of the inclined flange portion W _b of the intermediate material W ₂ in the direction of its thickness is reduced by the die 32 in the thickness increasing process, crushed 8 is caused to flow into the spaces b and c shown in FIG. 8 within the range of the thickness of the intermediate material W ₂ , thereby causing a thick portion in a part of the intermediate material W _2. Since W _d is formed, no fold defects are generated in the thick portion W _d , and therefore, machining for removing the fold defects is not required, and the thick portion W having no fold defects only by pressing. _{Since d} can be formed, the number of processing steps can be reduced and the cost can be reduced accordingly.
[0031]
Further, in this embodiment, since a method of cutting unnecessary portions by machining after a drawing process with a thick plate is not adopted, waste of materials can be saved, material costs can be reduced, and cost can be reduced. You can go down.
[0032]
Further, according to the method of the present invention, the thickness T and the height H of the thick portion W _g shown in FIG. 10 are about 1.5 times the thickness t of the sheet metal material W ₀ (T = 1.5 t, H = 1.5t). Incidentally, the width T ′ and the height H ′ of the thick part formed by the conventional upsetting increase by 20% of the material thickness t ′ at the maximum (T ′ = 1.2 t, H ′ = 1.2 t). )Met.
[0033]
One feature of the method of the present invention is that a thick portion can be formed only by press molding at an arbitrary intermediate position as well as the edge of the sheet metal material.
[0034]
【The invention's effect】
As is clear from the above description, according to the present invention, in the thickening step, a part of the inclined flange portion is crushed in the direction in which the plate thickness decreases, and the surplus generated by the crushing is reduced to the thickness of the sheet metal material. Since the thick part is formed in a part of the sheet metal by flowing within the range, no fold defect is generated in the thick part, and therefore, machining for removing the fold defect is unnecessary, and only the press work is performed. Thus, it is possible to form a thick portion without a folding defect in a part of the sheet metal, and it is possible to reduce the number of processing steps and reduce the cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a sheet metal material used in the method of the present invention.
FIG. 2 is a cross-sectional view for explaining drawing as a preliminary process in the method of the present invention.
FIG. 3 is a cross-sectional view for explaining a burring process as a preliminary process in the method of the present invention.
FIG. 4 is a cross-sectional view of an intermediate material obtained by a preliminary process in the method of the present invention.
FIG. 5 is a cross-sectional view of a main part of a press apparatus used for a thickening process.
FIG. 6 is a cross-sectional view of a main part of a press apparatus used for a thickening process.
FIG. 7 is a cross-sectional view of a main part of a press apparatus used for a thickening process.
8 is an enlarged detail view of a part A in FIG. 7;
FIG. 9 is a cross-sectional view of an intermediate material obtained by a preliminary and thickening process.
FIG. 10 is a cross-sectional view of an intermediate material obtained by a preliminary process, a thickening process, and a punching process.
FIG. 11 is a cross-sectional view of the final product.
FIG. 12 is a perspective view of the final product.
FIG. 13 is a cross-sectional view of a pulley.
FIG. 14 is a cross-sectional view showing a conventional example of a pulley manufacturing method.
FIG. 15 is a partial cross-sectional view showing a manufacturing method by upsetting.
[Explanation of symbols]
W ₀ , W ₀ ′ Sheet metal material W _{1 to} W ₄ Intermediate material W _b Inclined flange portion W _d , W _g Thick portion 21 Upper die 22 Lower die 25 Die ring 26 Punch 32 Die 33 Stripper

Claims (1)

A preliminary step of bending or drawing or burring the sheet metal material to obtain an intermediate material having a truncated cone-shaped inclined flange portion in part;
A part of the outer peripheral surface of the inclined flange portion of the intermediate material obtained by the preliminary process is plated by a die having a die having a truncated cone-shaped concave portion and a punch having a truncated cone-shaped convex portion. Crushing in the direction of decreasing thickness, surplus generated by crushing, into a ring-shaped space portion formed between the intermediate material and the mold, respectively , within the thickness range of the intermediate material A thickening step of forming a thick portion in a part of the intermediate material by flowing;
A thickening press method for sheet metal, characterized in that a part of the sheet metal is thickened through the process.

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