JPH0438892Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement of a hemming press die for performing hemming on the edge of a panel-shaped workpiece.

BACKGROUND TECHNOLOGY For example, in opening/closing bodies such as automobile doors and hoods, it is common to hem the flange portion of the peripheral edge of the outer panel to join it to the mating inner panel. Figure 5 shows an example of a press die for hemming.

In FIGS. 4 and 5, 1 is a punch as a lower die, and on this punch 1, for example, an outer panel P _a and an inner panel P _b of a hood are positioned as workpieces. outer panel
As shown in Fig. 7, flange portions F _a , F _b , and F _c are bent in advance on the peripheral edge of P _a , and among these flange portions, for example, flange portions F _a and F _c are bent. As shown in FIG. 6, the flange heights l and P are set to be different from each other.

Reference numeral 2 denotes an upper holder that moves up and down with respect to the punch 1, and a sectional die 3 for hemming processing is fixed to this upper holder 2, forming a hemming die 4. Further, a die holder 5 is elastically supported on the outer periphery of the upper holder 2 via an elastic body 6 such as urethane rubber so as to be movable up and down.A sectional die 7 for pre-hemming is fixed to this die holder 5, and a pre-hemming die 8 It consists of 9
is a retainer pin that regulates the vertical stroke of the die holder 5.

According to such a mold structure, in the process of lowering the upper holder 2, the sectional die 7 for pre-hemming comes into contact with the flange parts F _a , F _b , F _c before the other sectional dies 3 and As shown in Figure 6, the flange parts F _a , F _b , and F _c are bent to about 45 degrees and prehemmed. Then, when the upper holder 2 further descends, the sectional die 3 for hemming comes into contact with the flange parts F _a , F _b , F _c , and the flange parts F _a , F _b , F _c are further bent and hemmed. will be administered.

Problems to be solved by the invention In the above-mentioned press die, for example, as shown in Fig. 6, the flange portions on two opposite sides are
Although the heights l and P of F _a and F _c are different, the vertical stroke of the die holder 5 with respect to the upper holder 2 is constant, so the flange height l,
The timing at which the sectional die 7 hits the tips of the flange portions Fa _{and Fc} differs by the difference m in P.

Therefore, in the example of FIG. 6, the sectional die 7 first hits the flange portion F _a with the flange height l, so the sectional die 7
As a result, the outer panel P _a may be pushed in the direction of the arrow A in FIG. 6, causing a positional shift, making it impossible to perform proper hemming.

In order to prevent the above-mentioned forming defects, the present invention enables pre-hemming to be performed at the same timing even if there are differences in flange height.

Means for Solving the Problems As shown in the embodiments, the present invention consists of dividing a part of a pre-hemming die to form a separate floating die, and making this floating die the same as the pre-hemming die. It is characterized in that it is elastically supported on the hemming die so as to be slidable in the direction.

Function The floating die mentioned above has the same function as the pre-hemming die, so by setting the stroke of this floating die to be different from the stroke of the pre-hemming die,
The machining timing can be made the same even for parts having different flange heights as described above.

Embodiment FIGS. 1 and 2 are diagrams showing an embodiment of the present invention, and substantially the same parts as in FIG. 4 are given the same reference numerals.

In this embodiment, as shown in FIGS. 1 and 2, a floating holder 10 that can be slid relative to each other is provided between the upper holder 2 and the die holder 5, and a sectional die 7 for pre-hemming processing is provided.
Of these, a portion corresponding to the flange portion F _c of the outer panel P _a is divided into a separate sectional die 11 , and the floating die 12 is constructed by fixing this sectional die 11 to a floating holder 10 .

The floating holder 10 is individually elastically supported by the upper holder 2 via an elastic body 13 such as urethane rubber, and at the same time, the floating holder 10 is supported by retainer means (not shown) similar to the retainer pin 9 in FIG. The vertical stroke of the upper holder 2 is regulated by the upper holder 2.

Here, as shown in Fig. 6, the flange part F _a
Since there is a difference of m in the flange heights l and P between and F _c , the stroke of this difference m is added to the stroke of the sectional die 11 (floating die 12), thereby moving the upper holder 2 to the upper limit position. 3, the molding surface 11a of the sectional die 11 shown in FIG. 3 is not flush with the molding surface 7a of the sectional die 7, but is set to protrude below the molding surface 7a.

Therefore, according to the structure of the above embodiment, since the sectional die 3 constituting the pre-hemming die 4 and the sectional die 11 constituting the floating die 12 are independent from each other, the flange portion F as shown in FIG. The timing when the sectional die 7 hits _a is the same as the timing when the sectional die 11 hits the flange part _Fc , and even if there is a difference in height between the flange parts F _a and F _c , both are prehemmed at the same time. Therefore, it is possible to prevent the positional shift of the workpiece due to a delay in the molding timing as in the conventional method.

Effects of the invention According to the invention, a part of the pre-hemming die is divided into a floating die, and this floating die is elastically supported by the hemming die in the same way as the pre-hemming die. Therefore, even if there is a difference in the height of the flange formed by the floating die and the height of the flange formed by the floating die, the molding timing for both can be made the same, and the position of the workpiece due to the difference in molding timing as in the conventional method can be avoided. Prevents misalignment and performs hemming with high precision.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a bottom view of the upper mold in Figure 1, Figure 3 is an enlarged view of the main part of Figure 1 and corresponds to the - line cross section in Figure 7,
Figure 4 is a cross-sectional view of a conventional press die, and Figure 5 is a cross-sectional view of a conventional press die.
FIG. 6 is a bottom view of the upper die, FIG. 6 is an enlarged view of the main part of FIG. 4, and a view corresponding to the cross section taken along the line - in FIG. 7. FIG. 7 is a perspective view showing an example of the workpiece. 1... punch, 2... upper holder, 3... sectional die, 4... hemming die, 5... die holder, 6... elastic body, 7... sectional die,
8...Pre-hemming die, 10...Floating holder, 11...Sectional die, 12...
Floating die, F _a , F _c ... flange part,
P _a ... Outer panel as a workpiece.

Claims (1)

[Scope of utility model registration request] A hemming die that moves up and down with respect to a punch in which a workpiece is positioned elastically supports a pre-hemming die that is slidable in the same direction as the up and down direction of the hemming die, and a flange portion formed at the peripheral edge of the workpiece. In a hemming press type in which a pre-hemming process is performed using a pre-hemming die, and then a hemming process is performed using a hemming die, a part of the pre-hemming die is divided to form a separate floating die, A hemming press type characterized in that the floating die is elastically supported with respect to the hemming die so as to be slidable in the same direction as the pre-hemming die.