JPS6023045Y2 - press mold - Google Patents

Description

[Detailed description of the invention] This invention relates to a press die for bending a steel plate into an arc shape.

1, 2, 3, and 4 show conventional press dies.

Figure 1 shows a pair of left and right roller-shaped lower molds 2 placed on a pedestal 1, and the upper mold 3 is a narrow one with its lower end rounded into an arc shape. However, it shows a distribution type in which the upper mold 4 is wide and the arc of the lower surface is large.

In the press molds shown in FIGS. 3 and 4, the lower mold 5 has an arcuate concave upper surface, and the upper molds 3 and 4 are the same as those in FIGS. 1 and 2.

Among the conventional molds as described above, the one shown in FIG. 1 has a small load during bending, but the upper mold 3 is narrow, so it has the disadvantage that impressions are easily formed by the upper mold 3.

Therefore, the ones shown in FIGS. 2 to 4 are often used, especially the ones shown in FIGS. 3 and 4.

All of these can be considered to be centrally concentrated (distributed) from a mechanical point of view, but the load increases in the order of FIGS. 1, 2, 3, and 4.

Also, although the load in the one shown in Figure 3 is smaller than that in Figure 4, I am not impressed by the impressions left by the upper die.

The one in Fig. 4 has been improved to prevent impressions from forming, but it has the same effect as rolling and requires a large load, especially when the plate thickness is large.

This idea solves the above-mentioned drawbacks of conventional press molds, and uses a lower mold with a concave curved upper surface, and a brush mold that can be moved left and right on this upper surface. The present invention provides a press mold which is mounted so as to be fixed at any desired position.

The details of this invention will be explained in detail below based on the drawings from FIG. 5 onwards.

In FIGS. 5 and 6, 11 is a lower mold, and its upper surface 12 is a concave curved surface with radius R centered at point O.

Reference numeral 13 is a brush type, and its lower surface is an arc-shaped surface that fits the upper surface 12, and can be moved left and right and fixed at any position.The upper surface has a pair of left and right arc-shaped protrusions 14.
The center 01 of the radius r is from the 0 point to the brush type 1 as shown in Figure 6.
It is assumed that the point lies on a straight line with an angle β open to the left and right from the 0 point with respect to the straight line passing through the center of 3.

Moreover, the lower surface of the upper mold 15 has a radius R centered on the above-mentioned point O.
1 is an arcuate curved surface 16.

In such a press mold, when bending the very edge of the metal plate 17, the brush mold 13 is fixed by shifting it to the right by an angle α as shown in FIG. If the surface 14 is in a position tangentially touching the surface 16 of the upper mold 15, that is, the position is 11 to the left of the center of the lower mold 11 and the upper mold 15, it will bend well and have little springback.

After bending the ends of the metal plate 17 in this manner, the brush mold 13 is returned to the center and fixed as shown in FIG. 6, and the parts of the metal plate 17 following the ends are successively pressed.

In this state, the load during pressing is less than in the state shown in FIG. 5, and a stable arc can be obtained.

Next, the mechanical advantages of this invention will be explained, but to make it easier to understand, a comparison will be made with the conventional example shown in FIG.

Moreover, the one shown in FIG. 5 is shown as FIG. 7, and the one shown in FIG. 2 is shown as FIG. 9.

Further, respective vector diagrams are shown in FIGS. 10 and 11.

In FIGS. 10 and 11, a is the same in both cases when the metal plates to be bent are the same plate.

However, B2 is the same as B□ in the case of Figure 11, but
In the case of FIG. 10, 1□ is larger than 11, so Bt>Bird, and the resultant force P becomes P<P'.

The above load formula is shown as M... (1) P = Store In the above formula (1), if 1° is large and 1 and 12 are omitted approximately, then P = U - (2) ne o - p' = agony = companion = shinobi... (3) 121
□ 11 Comparing the above equations (2) and (3), it is found that P <P'.

However, in reality, 1° cannot be made very large, so P′
Although P is not twice as large as P, compared to the press type shown in Fig. 4, this invention is not a distributed type, so it can be about twice as effective.

The upper surface 12 of the lower mold 11 is made into an arcuate curved surface in order to prevent lateral loads from being applied to the upper mold 15 (the lateral loads are balanced in FIG. 10). Instead of a wide distribution type as shown in the figure, a narrow convex type may be used, but the distribution type has the advantage that it is difficult to form impressions.

Note that the same effect can be obtained by using a roller-shaped brush mold 13' as shown in FIG.

[Brief explanation of the drawing]

Figures 1 to 4 are front views showing each side of a conventional press mold, Figures 5 to 7 are front views showing each state of the press mold of this invention, and Figure 8 is a front view of another embodiment. Front view shown, No. 9
The figure is a front view of a conventional press die, and FIGS. 10 and 11 are vector diagrams of the press die of this invention and the conventional press die. 11...Lower mold, 12...Top surface, 13.
... Brush type, 14 ... Arc-shaped protruding surface, 15
...Upper mold, 17...Metal plate.

Claims (1)

[Scope of utility model registration request] a lower mold having an upper surface with a concave curved surface; a brush mold movable left and right along the upper surface of the lower mold and having a pair of left and right arch-shaped protrusions on the upper surface; A press die consisting of an upper die that presses a metal plate.