JPH0428653Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a press mold for bending and forming a flange portion, which is a so-called inverse portion, at the end of a panel-shaped workpiece.

2. Description of the Related Art For example, a press die having the structure shown in FIG. 3 is known as a press die for the purpose of flange forming. A collapse cam 2 is placed on the lower die 1, and a drive cam 3 is fixed to the collapse cam 2. The collapse cam 2 is connected to an air cylinder 4 and is capable of sliding on the lower die 1 in the horizontal direction. On the other hand, in addition to the drive cam 6, the upper mold 5 includes
A slide cam 7 corresponding to the drive cam 3 on the lower mold 1 side is attached. This slide cam 7
is horizontally slidable and is given a return force by a compression type coil spring 8.

In the forming procedure, the upper die 5 is lowered to hold the workpiece W on the collapse cam 2 by the pad 9 which is elastically supported on the upper die 5 side. After the collapse cam 2 and the upper mold 5 are positioned relative to each other by sliding contact between the guide surface 10 on the collapse cam 2 side and the drive cam 6, the drive cam 3 and the slide cam 7 come into sliding contact and the slide cam 7 slides in direction A. As a result, due to the cooperation of the collapse cam 2 and the slide cam 7, the flange portion F preformed in the previous process (the preformed shape is shown by an imaginary line) is folded so that its corner portion C forms an acute angle θ. Curved and at the same time horizontal leg Q
A bulging portion E will be formed in the area.

In this case, since the corner portion C is an acute angle as described above, the flange portion F becomes a so-called inverse portion, and even if the upper die 5 rises, it becomes difficult to take out the workpiece W directly above. Therefore,
After the upper die has been raised, the air cylinder 4 is operated to move the collapse cam 2 back to the imaginary line position, thereby making it possible to take out the workpiece W directly above.

Problems to be Solved by the Invention However, in the conventional mold structure, a problem similar to the corner part C occurs in the inverse part when the collapse cam 2 is slid. That is, since the slope G of the bulging portion E becomes an inverse portion, the oblique mold surface 2a of the collapse cam 2 pushes the flange portion F upward when the collapse cam 2 is moved in the direction A. As a result, the horizontal leg portion Q in particular of the flange portion F is deformed, resulting in a decrease in product quality.

Means for Solving the Problems The present invention provides a mold structure that can avoid inverse portions, particularly at the horizontal leg portions of the flange portions. Specifically, as shown in the examples, the portion of the collapse cam corresponding to the bulging portion of the flange portion is divided into a sectional punch, and the sectional punch is supported so as to be movable up and down relative to the lower die. The collapse cam is provided with a back cam that moves the sectional punch up and down in accordance with the horizontal sliding displacement of the collapse cam.

As is clear from FIG. 2, the sectional punch descends in conjunction with the horizontal displacement of the collapsing cam 2, making it possible to remove the workpiece W directly above without deformation of the flange portion F.

Embodiment FIGS. 1 and 2 are diagrams showing an embodiment of the present invention, and parts common to those in FIG. 3 are given the same reference numerals.

The collapse cam 2 is connected to a piston rod 4a of an air cylinder 4, and is configured to be able to slide horizontally on the lower die 1 by the operation of the air cylinder 4. A window 1a is formed in the center of the collapse cam 2, and a sectional punch 11 for forming the bulge Q of the flange F is disposed within the window 1a. The sectional punch 11 is guided by a rib 12 on the side of the lower mold 1 and can move up and down. Further, a retainer pin 14 having a compression type coil spring 13 is connected to the sectional punch 11, and the sectional punch 11 is always urged downward.

On the other hand, a wedge-shaped back cam 15 that fits into the lower surface of the sectional punch 11 is integrally fixed to the lower surface of the collapse cam 2. Therefore, the sectional punch 11 moves up and down in accordance with the sliding displacement of the back cam 15. The lower limit position of the sectional punch 11 is set at a position where the upper surface of the sectional punch 11 is flush with the upper plane 2b of the collapse cam 2, as shown in FIG.

In the above-described press die structure, press working is performed with the sectional punch 11 protruding from the upper plane 2b of the collapse cam 2, as shown in FIG. The collapse cam 2 and the slide cam 7 work together to form the flange part F into a predetermined shape, and at the same time, the sectional punch 11 and the slide cam 7 work together to form the bulge part E.

After the molding is completed, the air cylinder 4 is activated after the upper mold 5 is raised, and the collapse cam 2 slides in the direction A as shown in FIG. When the collapse cam 2 slides, the back cam 15 integrated with the collapse cam 2 also slides in the A direction, so the sectional punch 11 gradually descends by an amount corresponding to the amount of displacement of the back cam 15. That is, the sectional punch 11 gradually escapes downward by the force of the coil spring 13 until the upper surface of the sectional punch 11 becomes flush with the upper surface 2a of the collapse cam 2, and finally the state shown in FIG. 2 is reached. Therefore, in the process of sliding the collapse cam 2, the sectional punch 11 does not push up the horizontal leg portion Q of the flange portion F.

After the collapse cam 2 reaches the slide limit position, it becomes possible to take out the workpiece W from the lower mold 1 directly above.

Although the drive cam 3 is fixed to the collapse cam 2 in this embodiment, it may be fixed directly to the lower die 1 instead.

Effects of the invention As described above, according to the invention, the part of the flange part that forms the bulge of the horizontal leg is made independent as a sectional punch, and the bulge is formed in accordance with the displacement of the sectional punch and the collapse cam. Since the structure allows the workpiece to escape from the horizontal leg part, the horizontal leg part is not forced up when taking out the workpiece, and deformation of the workpiece can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is an explanatory diagram of the operation of FIG. 1, and FIG. 3 is a sectional view of a conventional press die. 1...Lower die, 2...Collapse cam, 3...Drive cam, 4...Air cylinder, 5...Upper die, 7
...Slide cam, 11...Sexual punch, 15...Back cam, W...Work, F...
Flange part, Q...Horizontal leg part, E...Bulging part.

Claims (1)

[Scope of utility model registration request] A collapse cam that can slide horizontally is installed on the lower mold, while a slide cam that slides horizontally in sliding contact with the drive cam fixed to the lower mold or the collapse cam is attached to the upper mold. In cooperation with the slide cam, a roughly L-shaped flange is bent and formed at an acute angle at the end of a panel-shaped workpiece, and at the same time, a bulge is formed on the horizontal legs of the flange. The press die is a press die in which a portion of the collapse cam corresponding to the bulge is divided into a sectional punch, and the sectional punch is supported so as to be movable up and down relative to the lower die, while the collapse cam is A press type characterized by being equipped with a pack cam that moves the sectional punch up and down according to the horizontal sliding displacement of the sectional punch.