JP3420798B2 - Press working method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press working method for bending a workpiece made of a plate material into a spherical shape. 2. Description of the Related Art In conventional drawing and bending processes of press working, a male mold is pressed into a workpiece (material) to plastically deform the workpiece. [0003] Therefore, in the conventional drawing and bending of press working, the shape of the product after the processing can be pushed into the male mold into the workpiece,
And after pushing the male mold into the workpiece and plastically deforming it,
The male mold is limited to a shape that allows the male mold to be pulled out from the workpiece, and there has been a problem that a shape in which the side wall portion swells outward cannot be machined. The present invention has been made in view of such circumstances, and provides a press working method capable of working a product having a shape that cannot be achieved by conventional drawing or bending in press working. The purpose is to: [0005] A press working method according to the present invention is a press working method for working a workpiece made of a plate material into a spherical shape, comprising a first mold and a first mold. a second mold to mold movable relatively linear direction, the the first die, wherein is provided so as to face the second mold to form a spherical curved surface A concave portion that is depressed, and is movable in the linear direction relative to the first mold and the second mold ;
And a biasing means for biasing the third mold toward the second mold, wherein the second mold and the third mold are provided. With the workpiece made of a plate material interposed therebetween, the second mold is relatively moved in the linear direction toward the first mold, and the second mold is moved. While holding the workpiece between the third mold, the workpiece is pushed toward the first mold against the urging means by the second mold, The workpiece is inserted into the recess while slidingly contacting the curved surface.
Finally, the tip of the workpiece is moved out of the third mold.
By abutting against the peripheral surface, the workpiece is deformed along the curved surface without sandwiching the workpiece between the first mold and the third mold. is there. According to the present invention, the workpiece is made to enter the concave portion of the first mold while sliding on the curved surface of the concave portion of the first mold, so that the workpiece is brought into the curved surface. In order to plastically deform the workpiece in a spherical shape, unlike the conventional press-drawing and bending,
Since the mold is not pushed into the work, the side wall portion is outward, as the mold (male mold) could not be pulled out from the work by conventional drawing or bending, and could not be processed. It is possible to process a spherical shape in which the bulging portion and the opening on the distal end side are narrower than the internal space. Also final
The tip of the workpiece is abutted against the outer peripheral surface of the third mold
The workpiece will try to bulge outwards,
Surface causes large plastic deformation of the workpiece
Progress and reduce the amount of springback after unloading
Can be . The present invention will be described below with reference to an embodiment shown in the drawings. 1 to 6 show an embodiment in which a workpiece is formed into a spherical shape according to the present invention. FIG. 1 shows a state before processing of a workpiece 1 in the present embodiment, and includes a cylindrical portion 1a,
A hemispherical portion 1b is formed continuously and integrally with one end of the cylindrical portion 1a. Such a workpiece 1 can be manufactured by drawing a flat plate of a metal plate such as a steel plate by drawing in a conventional press working. 2 to 5, reference numeral 3 denotes a fixed portion such as a bed of a press machine. Above the fixed portion 3, a fixed plate 5 provided with a hole 4 is fixed in a horizontal direction.
A first mold 6 is fixed on the fixing plate 5, and a hemispherical concave portion 7 opening upward is provided on an upper surface side of the first mold 6. The first die 6 is provided with a center hole 8 that passes through the center of the concave portion 7 and vertically passes through the die 6. The center hole 8 is the fixing plate 5
The hole 4 has the same diameter as that of the hole 4 and is positioned so that the center of the hole 4 coincides with the hole 4. As shown in FIG. 3 in an enlarged manner, a chamfered portion 9 having an arc-shaped cross section is provided at an edge of the concave portion 7. Reference numeral 10 denotes a second mold. The second mold 10 is mounted above a first mold 6 on a slide (not shown) of a press machine which moves vertically. ing. A hemispherical concave portion 11 that opens downward is provided on the lower surface side of the second mold 10. Here, the concave portions 7 and 11 have a diameter corresponding to the outer surface of the hemispherical portion 1b of the workpiece 1. Reference numeral 12 denotes a third die, which has a rod shape having a circular cross section, and has a collar portion 13 at an intermediate portion thereof. The upper end of the third mold 12 has a spherical shape corresponding to the inner surface of the hemispherical portion 1b of the workpiece 1. The upper part of the third mold 12 is fitted to the hole 4 of the fixing plate 5 and the center hole 8 of the first mold 6 so as to be movable in the vertical direction. A compression coil spring 14 is interposed between the lower surface of the collar portion 13 and the fixed portion 3, and the spring 14 urges the third mold 12 upward. Next, a press operation in this embodiment will be described. First, as shown in FIGS. 2 and 3, the hemispherical portion 1b
The opening end of the cylindrical portion 1a of the workpiece 1 is fitted to the edge of the concave portion 7 of the first mold 6 with the side facing upward. At this time, the third mold 12 is urged by the spring 14 and is at the upper limit position. At this upper limit position, the third mold 12
It is assumed that the upper end protrudes from the first mold so as to contact the inner surface of the hemispherical portion 1b of the workpiece 1. Next, the second mold 10 is lowered by lowering the slide of the press machine. Then
First, as shown in FIG. 4, the concave portion 11 of the second mold 10 fits into the hemispherical portion 1b of the workpiece 1, and the hemispherical portion 1b of the workpiece 1
Is sandwiched between the second mold 10 and the third mold 12. When the second mold 10 is further lowered, the third mold 12 also holds the workpiece 1 between the second mold 10 and the third mold 12 against the spring 14. It comes down with the second mold 10. At the same time, the cylindrical portion 1a of the workpiece 1 enters the concave portion 7 while sliding on the spherical surface of the concave portion 7 of the first mold 6, thereby causing the cylindrical portion 1a of the workpiece 1 to move. When the first mold 6 is plastically deformed into a spherical shape along the spherical surface of the concave portion 7 of the first mold 6 and the first mold 6 is lowered to the lower limit position as shown in FIG. Plastically deformed. As a result, the entire workpiece 1 has a spherical shape having the hole 15 corresponding to the third mold 12. In addition, as is apparent from FIG.
Indicates that the tip of the workpiece 13 projects into the outer peripheral surface of the third mold 12.
Hit. For this reason, the workpiece 1 tries to expand outward.
However, since it is restricted by the curved surface of the concave portion 7, the fitting piece
The plastic deformation of No. 3 greatly progressed, and the spring back after unloading
The amount of work can be reduced. FIG. 6 shows only the workpiece 1 (product) after the completion of such press working. According to this press working method, unlike the conventional press work of drawing and bending, the die is not pushed into the workpiece 1, so that the conventional drawing and bending work. For example, it is impossible to process a product having a spherical curved surface in which a side wall portion bulges outward and a distal opening portion (hole 15) is narrower than an internal space, such as the spherical product of the present embodiment. Can be. In this embodiment, the workpiece 1 is held between the second mold 10 and the third mold 12 while being supported between the second mold 10 and the third mold 12 as described above. Recess 7 of one mold 6
The workpiece 1 is made to enter the recess 7 while being in sliding contact with the curved surface, so that the workpiece 1 can be prevented from being crushed without being deformed into a shape to be processed. In the above embodiment, the portion of the workpiece 1 deformed by the concave portion 7 of the first die 6 has a continuous cylindrical shape over the entire circumference. The part of the workpiece that is deformed by the concave portion of the first mold may have another shape. As described above, according to the present invention, the side wall portion swells outward and the tip side open portion is narrower than the internal space, which was impossible with the conventional drawing or bending of press working. Can process products with a spherical curved surface and unload
Excellent is obtained an effect such that Ru can be suppressed the amount of springback after.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing only a workpiece before processing in an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a state of a die and a workpiece before processing in the embodiment. FIG. 3 is a longitudinal sectional view showing the vicinity of an edge of a concave portion of a first mold in the embodiment. FIG. 4 is a longitudinal sectional view showing a state where a second mold is lowered in the embodiment and a concave portion of the second mold is fitted to a workpiece. FIG. 5 is a longitudinal sectional view showing a state where a second mold has reached a lower limit position in the embodiment. FIG. 6 is a longitudinal sectional view showing a workpiece (product) after completion of press working in the embodiment. [Description of Signs] 1 Workpiece 6 First mold 7 Recess 10 Second mold 12 Third mold 14 Spring

Continuation of the front page (56) References JP-A-5-123741 (JP, A) JP-A-4-89152 (JP, A) JP-A-48-50974 (JP, A) JP-A-53-16356 (JP) , A) JP-A-50-75163 (JP, A) JP-A-49-94558 (JP, A) JP-B-47-48053 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B21D 51/02 B21D 51/08 B21D 22/00-26/14 B21D 41/04

Claims (1)

(57) [Claim 1] A press working method for working a workpiece made of a plate material into a spherical shape, comprising: a first mold and a first mold relative to the first mold. a recess and a second mold which is movable in a linear direction, the first die, wherein is provided so as to face the second mold, is recessed to form a spherical curved surface, met movable relative said linear direction relative to the first mold and the second mold
And a third mold that penetrates the concave portion in the linear direction, and an urging unit that urges the third mold toward the second mold. In a state where a workpiece made of a plate material is interposed between the mold and the third mold, the second mold is relatively moved in the linear direction toward the first mold. Then, the workpiece is sandwiched between the second mold and the third mold, and the workpiece is pressed against the urging means by the second mold. push toward one of the mold, said-out line by entering into the recess while the workpiece is brought into sliding contact with the curved surface, finally the workpiece tip of said third
By abutting against the outer peripheral surface of the mold, the workpiece is deformed along the curved surface without sandwiching the workpiece between the first mold and the third mold. Press working method characterized by making it.