JP2866630B2 - Thin plate mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin plate forming die.

[0002]

2. Description of the Related Art Negative angle forming of a thin plate such as a sheet metal or a plastic is usually performed using a slide cam. by the way,
Negative angle molding here means that when a workpiece placed on the lower mold is formed by lowering the upper mold in the vertical direction and abutting, it has a molding part that enters the lower mold from the processing locus of the upper mold. Say

In the conventional negative angle forming of a thin plate product, a work is placed on a lower die, the upper die is lowered vertically downward, and a passive cam of the lower die is driven by an operation cam of the upper die to move the side of the work. When the machining was completed and the upper die was raised, the passive cam was retracted by a spring. In this case, the forming part of the passive cam that forms the work by sliding from the outside of the work is formed in the same integral shape as the shape of the forming part of the work, but the lower die on which the work is placed is formed. Since the part must be removed from the lower mold after machining is completed, the negative angle of the lower mold is divided and retracted, or the rear part of the negative angle is deleted and the work is moved forward and Must be able to be taken out. This is not a problem when the degree of the negative angle is slight, but when the degree of the negative angle is large or when the product has an elongated frame-shaped cross section, such as a front pillar outer part of a sheet metal part of an automobile. Since the width of the groove of the work is narrow, if the lower mold part that becomes a negative angle is divided or deleted, not only the shape cannot be clearly formed at the molding part of the passive cam but also the strength of the lower mold is insufficient and Square forming was not possible.

Further, in the negative angle forming by the slide cam, since the passive cam is formed by sliding over a considerably long linear distance, it is not always easy to repeatedly slide the passive cam exactly to a predetermined position. In addition, it is difficult to produce products of stable quality. In addition, the product may be twisted or distorted, and the product may need to be modified.However, the outer panels of the car, such as the side panel, front fender, roof, hood, trunk lid, door panel, and front pillar outer, are configured. Such a part has a three-dimensional curved surface / curve, and it is practically impossible to modify the product. In the case of sheet metal assembly of automobiles, if the product is twisted or distorted, it is difficult to combine with other parts and it is not possible to provide a high quality automobile sheet metal structure, and it is possible to maintain the predetermined product precision of thin sheet molded products could not.

In addition, when a slide cam is used, a large passive cam or heel is provided on the side on which the work of the lower die is mounted, so that the area of the lower die is increased. Had become. Therefore, in order to solve the above problems, a method of forming a thin plate for converting a linear motion in the vertical direction of a press into a rotary motion and a forming die thereof have already been proposed by the present applicant as Japanese Patent Publication No. 63-41662. I have.

First, the molding die will be described in detail with reference to FIGS. FIG. 4 is a schematic left and right perspective view of a finished product of a front pillar outer, which is a sheet metal part of an automobile formed by the molding die. In the figure, the lower part is for right and the upper part is for left. This front pillar outer is part of the front door frame, part of the windshield frame, and also part of the frame that supports the roof panel, and has connections for many parts. However, it is a product that requires strict product accuracy, and if the accuracy is not satisfied, it is impossible to provide a sheet metal body of good quality.

The front pillar outer has a three-dimensional curved surface / curve to constitute an outer plate portion of an automobile. The part formed by the negative angle molding by the main mold is a part indicated by F, and its cross section is shown as a work W in FIG. That is, the work W shown in FIG.
After the negative angle forming from the state shown in FIG. 8, the state shown in FIG. 8 is obtained. Incidentally, in this press working step, first, drawing processing is performed, then, outer peripheral trimming processing is performed in a state shown in FIG. 5, and there is a main forming step as a third step thereafter.

In the lower mold 100, a cylindrical rotary cam 102 having a groove 101 formed in the axial direction is rotatably provided on a lower mold body 103. The lower die body 103 is provided with a bolt 1 on a lower substrate 121.
22. The upper surface of the lower die body 103 is formed in a shape capable of mounting the work W, and the negative angle forming portion 104 is formed on the edge of the groove 101 of the rotary cam 102 near the upper surface of the lower die 103.
To form After the work W is formed, an automatic return device 105 for rotating and retracting the rotary cam 102 so as to be able to be taken out from the lower mold body 103 is embedded in the lower mold body 103. In this example, the automatic return device 105 includes a push pin 107 urged by a coil spring 106 fixed to a surface of the groove 101 of the rotary cam 102 facing the negative angle forming portion 104 with a bolt 151 with a lower end of a rotary plate 108. Contact. The automatic return device 105 may be a pneumatic device, a hydraulic device, a link mechanism, a cam, or a mechanism similar thereto.
It can also be provided between them.

On the other hand, the upper die 109 has the rotary cam 102.
The slide cam 110 is provided at a position opposed to. This slide cam 110 forms a negative angle forming portion 112 at the lower end,
The slide cam 110 is guided by a guide (not shown), and a bolt 1 is attached to the upper surface of the slide cam 110 and the upper substrate 152.
A coil spring 117 compressed between the lower surface of the inclined guide 154 and the lower surface of the inclined guide 154 is urged outward from the mold. The slide cam 110 is stopped by a stop plate 156 fixed to the inclined guide 154 by bolts 155. The pad 157 is urged downward by a coil spring 158, is suspended from the upper substrate 152 by a suspension bolt 119, and strongly pushes the work W to the lower die body 103 so that the work W does not move before forming the work W at a negative angle. Press.

Next, the operation of the mold will be described.
First, as shown in FIG. 5, the upper die 109 is located at the top dead center, and at this time, the work W
Is placed. At this time, the rotating cam 102 is set to the automatic return device 1
05, it is turned back. Next, as shown in FIG. 6, first, the lower surface of the slide cam 110 is moved downward without the slide cam 110 interfering with the negative angle forming portion 104 of the rotary cam 102, as shown in FIG.
8 to rotate the rotating cam 102 clockwise in FIG.

When the upper mold 109 continues to descend, the slide cam 110 urged in the outward direction of the mold moves leftward in the horizontal direction by the action of the cam against the urging force of the coil spring 117. 7, the negative angle forming part 104 of the rotating rotary cam 102 and the slide cam 1 are rotated.
The workpiece W is negative-angle-formed with the ten negative-angle forming portions 112.

After the negative angle forming, the upper mold 109 starts to rise.
The slide cam 110 is urged outward from the mold by the coil spring 117, moves to the right in FIG. 8, and rises without interfering with the workpiece W formed with the negative angle.
On the other hand, the rotating cam 102 is
8 is rotated by the automatic return device 105 to the right in FIG.
3, the work W can be taken out without interfering with the negative angle forming part 104 of the rotary cam 102.

[0013]

As described above, the negative angle forming of a thin sheet product is performed using the rotating cam.
Since the rotating cam rotates around the rotation axis to machine the work, unless the work is substantially linear and largely bent when viewed from the working direction, a negative angle is formed in one cylindrical rotating cam having the same diameter. Although the formed part can be machined, if the work is greatly bent, the negative angle formed part cannot fit into one cylindrical rotary cam having the same diameter, and processing cannot be performed.

In particular, sheet metal parts of automobiles have many bent parts such as door panels, and in recent years, there are many bent parts, and in addition, there are many negative angle forming parts due to design reasons. There is a demand for improving the production efficiency by enabling molding in one step without using many steps.

[0015]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention forms a large bent negative angle forming portion with a single rotating cam having a plurality of cylindrical rotating cam portions having different diameters. This is a thin plate forming die. The size of the diameter of the rotating cam cannot be increased unreasonably in practice from the viewpoint of manufacturing a mold, and is, for example, about 320 mm, and a large bent work includes a plurality of columnar rotating cam portions having different diameters. One rotating cam is provided. The diameter is changed at a predetermined position of the rotating shaft according to the degree of bending of the work. Also, the size of the diameter of the rotating cam is taken into consideration so that the negative angle forming portion of the rotating cam does not become too sharp. If the negative angle forming portion of the rotating cam becomes an acute angle, the strength becomes insufficient, so that it is preferable that the angle does not become 30 ° or less.

Further, in the present invention, since one rotating cam is used, when a plurality of rotating cams are used, when the rotating cams rotate, end faces thereof may interfere with each other at a joint between adjacent rotating cams. But there is nothing like that.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to a specific embodiment shown in FIGS. The workpiece W to be molded by the molding die of the present invention is a trunk lid outer of an automobile as shown in FIG. As shown in FIG. 2, the negative angle is formed so as to change from the upper cross section to the lower cross section.

FIG. 1 is a plan view of a mold for forming the present thin plate, FIG. 2 is a view showing a state of a flange 1 before and after forming a work W, and FIG.
The I-III sectional view is shown. The processed portion of the work W of this thin mold is the rear edge of the trunk lid outer, as shown in FIG. 1, is convex in plan view, and both ends are considerably displaced forward. In order to work with one rotating cam, a very large rotating cam must be used. In making the mold, it is practically impossible to increase the size unnecessarily, and the maximum diameter is about 320 mm. In addition, there are cases where the flange angle is different between the center portion and both end portions, and the negative angle forming portion of the rotating cam becomes too acute to maintain the strength. In the present invention, the rotary cam is formed on the small-diameter central rotary cam portion at the center and the large-diameter double-ended rotary cam portions at both ends.

The small diameter of the rotating shaft C _A in FIG. 1 the central rotary cam section 2
The rotating cam 3 composed of the large-diameter end rotating cam portion 3 is disposed at both ends of the rotating cam 3. As can be seen from FIG.
Is concentric with the small-diameter central rotating cam portion 2 and has a larger diameter than the small-diameter central rotating cam portion 2. For example, the diameter of the large-diameter end rotating cam portion is 290 mm, and the diameter of the small-diameter end rotating cam portion is 2 mm.
50 mm.

The lower die 5 is, as shown in FIG.
A support block 8 is fixed to the support block 8 with bolts 7, and a cylindrical large-diameter end rotary cam portion 3 having a groove 10 formed in the axial direction in a horizontal hole groove 9 at the center of the upper surface of the support block 8 is rotatable. To support. In this embodiment, as shown in FIG. 1, an air cylinder 11 is provided as an automatic return device for the rotary cam 4. Needless to say, the automatic return device is not limited to an air cylinder, but may be a spring, a hydraulic device, a link mechanism, a cam or a mechanism similar thereto, and may be provided not only in a lower die but also in a vertical die.

A connecting member 1 is provided on the lower surface of the small-diameter center rotating cam portion 2.
2, and the connecting member 12 is pivotally attached to the distal end of a piston rod 15 of an air cylinder 11 whose base end is pivotally attached via a bracket 14 fixed to a support block 8 with bolts 13, and the piston rod 14 is contracted. Thus, the large-diameter center rotating cam portion 2 is returned. At the bottom of the hole 9 of the support block 8, there is provided a window hole that allows the connecting member 12 to swing.

A negative angle forming portion 16 is formed at the edge of the groove 10 of the end rotary cam portion 3, and a rotating plate 17 is fixed by bolts 18 on the side of the groove 10 facing the negative angle forming portion 16. ing. Further, the negative angle forming portion 1 of the large diameter end rotating cam portion 3
6 is formed on a work supporting portion 19 having the same shape as the lower surface of the work W so as to be able to support the work W, and the lower surface of the work W is shifted toward the upper outside connected to the work supporting portion 19 of the end rotating cam portion 3 of the support block 8. To form a work placement part 20 having the same shape as that of the work placement part 20.

The upper die 21 has a support block 23 fixed to the lower surface of the upper base 22 with bolts 24, a wear plate 25 fixed to the lower slope of the support block 23 with bolts 26, and slides on the lower surface of the wear plate 25. The cam 27 is slid while being held by a guide plate (not shown). Slide cam 27
A negative angle forming portion 28 is fixed to a portion of the end portion of the end rotating cam portion 3 facing the groove 10 with a bolt 29.

A receiving plate 29 is provided on the upper slope of the slide cam 27.
Are fixed by bolts 30, and the coil spring 3 is fixed between the receiving plate 29 and the support plate 31 fixed to the support block 23.
2, the slide cam 27 is urged toward the outside of the mold. The coil spring 32 is provided on the support plate 3.
1 is externally fitted to the positioning pin 33 screwed to
A tip end of the positioning pin 33 penetrates a stop plate 34 fixed to a side surface facing the support plate 31. Upper die 21
Is raised, the slide cam 27 moves outward from the mold until the receiving plate 29 comes into contact with the stop plate 34 by the urging force of the coil spring 32.

Although not shown, the work W
In order to stably support the work W, a positioning member for the work W is provided on the lower mold 5, and the upper mold 21 is provided with a pad for pressing the work W on the lower mold 5 as described in the conventional example. , Because it becomes complicated and it becomes difficult to understand the main part of the present invention,
The positioning member and the pad are omitted. The central portion of the work W is shown in FIG. 3 by a two-dot chain line with a small-diameter central rotating cam portion 2 and otherwise substantially the same as the large-diameter rotating cam portion.

Next, the operation of the mold for forming the present thin plate will be described. The state shown in FIG. 3 shows the state of the bottom dead center, and corresponds to FIG. 7 of the conventional example. Although not shown in the present invention, as shown in FIG. 5 of the conventional example, the upper die 21 is located at the top dead center, and at this time, the work W is mounted on the work mounting part 20 of the lower die 5. At this time, the rotary cam 4 has been rotated and retracted by the air cylinder 11.

Next, as shown in FIG. 6 of a conventional example, the upper die 21 firstly moves the slide cam 27 to the negative angle forming portion 16 of the small-diameter central rotary cam portion 2 and the large-diameter end rotary cam portion 3. The slope 41 of the slide cam 27 abuts on the rotation plate 17 without interference, and rotates counterclockwise through the small-diameter central rotary cam portion 2 and the large-diameter end rotary cam portion 3 (the rotation direction is opposite in the conventional example and the present embodiment). ).

When the upper mold 21 continues to descend, the slide cam 27 urged in the outward direction of the mold moves to the right in the lateral direction by the action of the cam against the urging force of the coil spring 32. The state shown in FIG. 7 of the conventional example, that is, FIG.
, And the negative angle forming portion 16 of the rotated small-diameter central rotary cam portion 2 and large-diameter end rotary cam portion 3 and the slide cam 2
The workpiece W is formed with the negative angle forming section 28 at the negative angle.

After the negative angle forming, the upper mold 21 starts to rise. The slide cam 27 is urged outward from the mold by a coil spring 32, and moves to the left to ascend without interfering with the negative-angle-formed workpiece W, as shown in FIG. On the other hand, the small-diameter central rotary cam portion 2 and the large-diameter end rotary cam portion 3 rotate leftward in FIG. 3 when the constrained slide cam 27 rises and the air cylinder 11 contracts the piston rod 15. Lower die 5 of workpiece W formed with negative angle
When the work W is taken out, the work W
The large-diameter end rotating cam portion 3 can be taken out without interfering with the negative angle forming portion 16.

[0030]

According to the present invention, as described above, the first type has the second type.
A molding die having a molding portion that forms a negative angle when the mold is moved in a linear direction to form an abutment, wherein a cylindrical rotary cam having a groove formed in an axial direction is rotatable to the first mold. And forming a negative angle forming portion at the groove edge of the rotating cam, and providing a slide cam having the negative angle forming portion in the second mold so as to face the rotating cam until the workpiece can be removed from the first mold after forming. In a thin plate forming die provided with an automatic return device for rotating and retracting a rotating cam in a first die, a large bent negative angle forming portion is processed by one rotating cam including a plurality of cylindrical rotating cam portions having different diameters. Since it is a thin plate forming die, it is possible to form a large bent negative angle forming portion with one forming die, thereby reducing the number of steps and improving processing accuracy.

In particular, the mold for forming a thin plate according to the present invention is suitable for forming a negative angle at a convex arc-shaped curved portion in plan view. Since the formed flange is a convex shape, it becomes a shrinking flange, and wrinkles are easily generated at the time of forming. In the present invention, since the rotary cam is formed as an integral body, bottom butting can be accurately performed. Further, in the present invention, since the negative angle forming part which is greatly bent is formed in a plurality of diameter parts, it is possible to take care that the negative angle forming part of the rotating cam does not become too sharp, so that the rotating cam becomes insufficient in strength. There is nothing.

Further, since one rotating cam is used in the present invention, when a plurality of rotating cams rotate, end faces of the rotating cams may interfere with each other at a joint portion between adjacent rotating cams.
Not at all.

[Brief description of the drawings]

FIG. 1 is a plan view of a specific embodiment of the present invention.

FIG. 2 is a two-sided view of a cross section of the work taken along the line III-III of FIG. 1 before negative angle forming and a cross section after negative angle forming.

FIG. 3 is a vertical sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a schematic left and right perspective view of a finished product of a front pillar outer, which is a sheet metal part of an automobile.

5 is a longitudinal sectional view showing a state in which an upper die of a molding die for molding the front pillar outer of FIG. 4 at a negative angle is at a top dead center.

6 is a longitudinal sectional view of a state in which the upper mold of FIG. 5 is lowered and the lower mold contacts.

FIG. 7 is a longitudinal sectional view showing a state where the upper die of FIG. 5 is at a bottom dead center.

FIG. 8 is a vertical cross-sectional view of the mold of FIG. 5 in a state where the upper mold is lifted by molding at a negative angle and is at a top dead center.

[Explanation of symbols]

 W ... Work 1 ... Flange 2 ... Small diameter center rotating cam part 3 ... Large diameter end rotating cam part 5 ... Lower die 21 ... Upper die 27 ... Slide cam

Claims (1)

(57) [Claims] 1. A molding die having a molding part having a negative angle when a second die is moved in a linear direction to a first die to form an abutment, and has a cylindrical shape having a groove formed in an axial direction. Rotating cam 1
A negative angle forming portion is formed on the groove edge of the rotating cam, and a slide cam having the negative angle forming portion is provided on the second die so as to face the rotating cam, and the formed work is formed on the first die. In a thin plate forming die provided with an automatic return device for rotating and retracting a rotary cam to a state where the rotary cam can be removed from the die, a large bent negative angle forming portion including a plurality of cylindrical rotary cam portions having different diameters. A thin plate forming die designed to be processed with a rotary cam.