JP2543770B2 - Press molding equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sheet metal press forming apparatus.

<Prior Art> For example, in the case of an automobile quarter panel as shown in FIG. 6, a rectangular recess H is simultaneously press-formed in the plane of the sheet metal W at the fuel injection port.

As shown in FIG. 7, a sheet metal press molding apparatus having such a shape is a press die including an upper die 1 having an upper die punch 2 and a lower die 3 corresponding to the shape of the upper die punch 2. The lower die 3 is provided with a rectangular protrusion 4 on the plane portion thereof, the upper die 2 is provided with a recess 5 corresponding to the protrusion 4, and the sheet metal W set on the lower die 3 is lowered to the upper die 1. The recess H is simultaneously formed by the movement.

<Problems to be Solved by the Invention> According to the above-described conventional press-forming apparatus, as shown in FIG. 8, the periphery of the recess 5 presses the upper surface of the sheet metal W at the portion of the projecting portion 4, and the sheet metal W and the lower die. The sheet metal W warps at the beginning of hitting 3. As a result, as shown in FIG.
However, there was a problem that distortion 6 was generated at the four corners.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned conventional problems, and the gist of the constitution that characterizes the present invention lies in the plane of a sheet metal press-molded by an upper die and a lower die. An apparatus for simultaneously drawing rectangular recesses, in which a lower punch is provided on the lower die side so that it can project from the lower die surface, and an upper die punch capable of moving relative to the upper die is provided on the upper die side. The die punch is provided with a receiving member facing the lower die punch so as to be retractable from the upper die punch surface by a spring, and the sheet metal is fixed to the lower die between the upper die and the lower die several millimeters before the upper die bottom dead point. A lever structure for interlocking the lower die punch with the lowering movement of the upper die is provided between the point just before the point and the bottom dead center, and the lever structure is pivotally supported by the lower die so as to be vertically swingable by a fulcrum. One end is pivotally attached to the lower die punch and the other end is on the lower die. It is pivotally attached to a passive rod held so as to be movable downward, and the length b from the fulcrum to the pivotal attachment point of the lower die punch is made larger than the length a from the fulcrum to the pivotal attachment point of the passive rod. b> a lever having a lever ratio, the passive rod is brought into contact with the upper die punch, and the lever causes the lower die punch to project from the lower die surface several times faster than the lowering speed of the upper die. It is equipped with an actuating rod.

<Operation> In the above-described device of the present invention, the sheet metal held by the lower die and the upper die punch, and the lower die punch on the lower die side and the receiving member on the upper die side moves from just before bottom dead center as the upper die moves downward. The lower die punch protruding at a speed faster than the lowering speed of the upper die draws the concave portion, and the periphery thereof is fixed, so that no distortion occurs.

<Examples> Examples of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the press die used in the apparatus of the present invention comprises an upper die 10, an upper die punch 11 and a lower die 12, and a lower die punch 13 for forming a recess H in the lower die 12 is lowered. The upper die 11 is provided with a receiving member 14 facing the lower die punch 13 so as to project from the die surface, and is pressed by a spring 15 so as to be retractable from the surface of the upper die 10.

The lower die punch 13 is adapted to project from the lower die surface at a speed several times faster than the lowering speed of the upper die 10 from just before the bottom dead center of the upper die 10 to the bottom dead center. The operating speed of the lower die punch 13 utilizes the lowering movement of the upper die 10 as shown in FIG. 1 to save energy and simplify the mechanism due to the lever structure.

The lever structure is as follows. That is, the lower mold 12 is attached with a lever 16 that swings up and down by a fulcrum 17,
One end of this lever 16 is pivotally attached 19 to the lower punch 13.
The other end of the lever 16 is pivotally attached 20 to a passive rod 18 held by the lower mold 12 so as to be vertically movable.

The length b between the fulcrum 17 of this lever 16 and the two pivot points 19, 20
The lever ratio of a has a relation of b> a as shown in FIG. 5 (C), whereby the molding speed = upper die lowering speed × a / b. That is, the ascending speed of the lower die punch 13 is set to several times the descending speed of the upper die 10 by the lever ratio.

On the other hand, on the upper die 10 side, an operating rod 21 that comes into contact with the passive rod 18 is provided integrally with the upper die punch 11. The operating rod 21 is brought into contact with the passive rod 18 a few millimeters before the bottom dead center of the upper die 10.

Therefore, due to the stroke A of the operating rod 21 up to the bottom dead center of the upper die 10, the lifting stroke B of the lower die punch 13 is the stroke A of the operating rod 21 depending on the lever ratio of the lever 16.
N times, and thus the depth of the recess H is obtained.

The press molding of the device of the present invention using such a press die will be described. First, as shown in FIG. 1, the plate mold W is set on the lower mold 12.

Then, the upper die 10 is moved downward and, as shown in FIG.
By pressing the sheet metal W, the blank hold state is obtained.

Further, when the upper die punch 11 moves downward and reaches a position just before the bottom dead center of several millimeters, the lower die punch is moved as shown in FIGS. 3 and 5 (A).
The sheet metal W of the sheet metal around 13 has a lower die 12 and an upper die punch 11
Then, the working rod 21 is brought into contact with the passive rod 18 by being pressed by.

At this time point, the lower die punch 13 starts to move upward, and from this point onward, the die punch 13 reaches the bottom dead center shown in FIG. 4 and FIG. 5 (C) from just before the bottom dead center. Rises at a speed several times faster than the lowering speed of the upper die punch 11, and is formed into a recessed portion H having a required depth by a sheet metal W in a portion held by the lower die punch 13 and the receiving member 14, so-called drawing. It is.

<Effects of the Invention> As described above, according to the present invention, the sheet metal around the lower die punch for forming the recess formed in the lower die by the upper die punch that moves relative to the upper die when the upper die moves downward is placed on the lower die. A lever having a lever ratio of b> a in which the length b from the fulcrum to the pivot point of the lower die punch for forming the recess is larger than the length a from the fulcrum to the pivot point of the passive rod in a fixed state. Since the lower die punch for forming the recess is projected at a speed several times faster than the lowering speed of the upper die from the position just before the lower fulcrum of the upper die by the lever structure, the recess is formed in an instant. Press molding with good quality can be performed without distortion in the four corners.

[Brief description of drawings]

1, 2, 3, 4, and 5 are sectional views showing an embodiment of the device of the present invention, and FIG. 6 is a perspective view showing an example of a sheet metal member press-molded by the device of the present invention. FIG. 7 is a cross-sectional view of a conventional press mold, FIG. 8 is an enlarged view of an arrow VIII in FIG. 7, and FIG. 9 is an explanatory view of conventional problems. 10 …… Upper die, 11 …… Upper die punch, 12 …… Lower die, 13 …… Lower die punch, 14 …… Receiving member, 15 …… Spring, 16 ……
Lever, 18 ... Passive rod, 21 ... Actuating rod.

Claims (1)

(57) [Claims] 1. A device for simultaneously drawing a rectangular recess in the plane of a sheet metal press-formed by an upper die and a lower die, wherein a lower punch is provided on the lower die side so as to project from the lower die surface. An upper die punch capable of moving relative to the upper die is provided on the upper die side, and a receiving member facing the lower die punch is provided on the upper die punch by a spring so as to be retractable from the upper die punch surface. After fixing the sheet metal between the upper and lower molds several millimeters before the bottom dead center of the upper die, a lever structure is provided in which the lower die punch is interlocked by the lowering movement of the upper die between the position just before the bottom dead center and the bottom dead center. The structure is pivotally supported on the lower die by a fulcrum so as to be vertically swingable, one end is pivotally attached to the lower die punch, and the other end is pivotally attached to a passive rod held in the lower die so as to be vertically movable. , Length b from the fulcrum to the pivot point of the lower punch
Is the length a from the fulcrum to the pivot point of the passive rod.
A lever having a lever ratio of b> a which is larger than that of the lower die from the lower die surface at a speed several times faster than the lowering speed of the upper die by contacting the passive rod with the upper die punch. A press forming apparatus comprising an operating rod for projecting a punch.