JPH06190458A - Hemming device - Google Patents

Abstract

PURPOSE:To make possible hemming through a simple structure without the buckling and deformation of a work. CONSTITUTION:A bracket 22 is attached oscillatably to an upper die 12 by the use of a horizontal axis 24; to this bracket 22, a hem blade 24 is fixed which is engaged with the bending flange W of a work W1 mounted on the work mounting part 13 of a lower die; the upper die is lowered in a state where the bracket 22 is abutted on a first stopper 28 by a tension spring 25; and the bracket 22 is oscillated by the use of a reaction from the bending flange W. Thus, the hem blade 24 is moved along the bending outline of the bending flange W, and pre-hemming and regular hemming are continuously performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemming device for bending a bending flange at one end of one work to sandwich the other work.

[0002]

2. Description of the Related Art Conventionally, in order to carry out hemming, generally, as shown in FIG. 7, a work 3 having a bending flange 2 on a lower die 1 and a work (a mating work) 4 having a flat end portion.
Then, the prehem blade 5 is moved obliquely downward as indicated by an arrow a in accordance with the lowering of the upper die (not shown), and the bending flange 2 of the work 3 is moved by the prehem blade 5. Is pre-bent by a predetermined angle (pre-hemming), then the pre-hem blade 5 is retracted from the working area, and the bending flange 2 is bent by the hem blade 6 descending in the vertical direction (pressing direction) as indicated by an arrow b. The main work 4 was sandwiched by the main bending (main hemming).

However, according to the above processing method, the prehem blade 5 must be moved obliquely downward (in the direction of arrow a) in accordance with the lowering of the upper die, so that a complicated shifting cam mechanism is required and the structure of the apparatus is reduced. There was a problem in that it was inevitable that it would become complicated and large. Further, when the angle of the bending flange 2 becomes large due to the convenience of pre-processing so that the bending flange stands upright in the pressing direction b, the sliding of the bending flange 2 with respect to the processing surface 5a of the prehem blade 5 by the friction force (arrow). (indicated by c) is suppressed, and problems such as buckling 7 and deformation 8 occur in the work 3. In addition,
If the angle θ formed between the pressing direction b and the processing surface 5a of the prehem blade 5 is reduced, the slip is promoted, but in this case, the prehemming amount is insufficient and the main hemming becomes difficult, It is not a fundamental measure.

Therefore, in Japanese Patent Laid-Open No. 56-131018, a hem blade is swingably attached to an upper die via a link, and a pivot provided on the hem blade is lowered to a lower die as the upper die descends. A hemming processing apparatus has been proposed which engages with a support stopper provided and rotates a hem blade about the pivot to perform pre-hemming and main hemming continuously. According to this hemming device, since only one hem blade is required to be provided, the structure is simpler than that of the general device, and since the rotation of the hem blade is utilized, the occurrence of buckling or deformation can be prevented. become.

[0005]

However, according to the hemming apparatus disclosed in the above publication, since a rotating mechanism such as a link mechanism, a pivot and a support stopper is required, the degree of simplification of the structure is high. There was another shortage, and there were many problems in terms of assembly and cost.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to achieve a further simplification of the structure while causing problems such as buckling and deformation. An object of the present invention is to provide a hemming processing device capable of reliably preventing the occurrence of

[0007]

In order to achieve the above object, the present invention has a bracket attached to an upper mold so as to be swingable about a horizontal axis, and the lower mold is attached to the bracket in accordance with the lowering of the upper mold. A hem blade is supported so that it can be engaged with a bending flange of an upper workpiece, and the bracket is urged between the upper die and the bracket to displace the hem blade in a direction opposite to the bending direction of the bending flange. The upper die is provided with two stoppers for interposing the urging means for controlling the swing of the bracket to position the hem blade in the initial pre-hemming posture and the main hemming posture. Is characterized by.

[0008]

In the hemming apparatus configured as described above, by adjusting the urging force of the urging means, the hem blade moves along the bending locus of the bending flange according to the lowering of the upper die, and the prehemming operation is performed. And hemming can be done continuously.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 4 show a first embodiment of the present invention. In these figures, 11 is a lower mold, 12 is an upper mold, and the lower mold 11 is provided with a first work (outer panel) W ₁ and a second work (inner panel) W ₂ which are targets for hemming. A work placing portion 13 for positioning and placing is provided. The upper die 12 is attached to a press ram (not shown) so as to move toward and away from the lower die 11 integrally with the press ram. Further, the work rest part 13 is shown in FIG.
The portion located on the right side of is a hemming portion 14, and the outer panel W ₁ is placed on the work placing portion 13 with the bending flange w corresponding to the hemming portion 14. Each of the lower die 11 and the upper die 12 is provided with a guide rod 15 and a guide tube 16 that can be fitted to each other (Fig. 4).
12 smooth movements are guaranteed.

A supporting portion 20 is formed on one side of the upper die 12 so as to project downward, and a central portion of an L-shaped bracket 22 is rotatable on the supporting portion 20 by using a horizontal shaft 21. Are combined. The bracket 22 is configured to swing about the horizontal axis 21 in a direction intersecting with the hemming processing portion 14 of the work placing portion 13, and one end portion thereof located above the hemming processing portion 14 is provided. A hem blade 24 is attached using bolts 23. The hem blade 24 has a flat surface 24a and an inclined surface 24b that can be aligned with the receiving surface 14a of the hemming portion 14 in a continuous manner at the tip extending downward.

On the other hand, a coil spring 25 is stretched between the other end of the bracket 22 and the upper die 12. The coil spring 25 is a tension spring, and both ends of the coil spring 25 are hooked on the bracket 22 and pins 26 and 27 provided on the upper die 12. The coil spring 25 urges the bracket 22 in the counterclockwise direction in FIG. 1, so that the hem blade 24 is separated from the hemming portion 14 of the lower mold 11 to the outside of the mold in a direction intersecting the pressing direction P. Direction, that is, in the direction opposite to the bending direction of the bending flange w.

On the other hand, a first stopper for restricting the swing of the bracket 22 is provided at a portion of the upper die 12 that sandwiches the support portion 20.
28 and a second stopper 29 are provided. The first stopper 28 restricts swinging of the bracket 22 in the counterclockwise direction (FIG. 1).
In a state where 22 abuts, the heme blade 24, the flat surface 24a with respect to the bent flange w outer panel W ₁ placed on the workpiece support 13 as shown in FIG. 1 by the two-dot chain line
Are positioned in the initial pre-hemming posture corresponding to the above.
Further, the second stopper 29 regulates the swinging of the bracket 22 in the clockwise direction, and when the bracket 22 is in contact with the second stopper 29, the hem blade 24 moves to the work mounting portion 13 The hemming portion 14 is positioned in the main hemming posture with its inclined surface 24b facing the receiving surface 14a. The bracket 22 is always kept in contact with the first stopper 28 by the bias of the coil spring 25.

The operation of the first embodiment will be described below.

In the hemming process, the upper die 12 is separated from the lower die 11 in advance (the mold is opened), and the inner panel W ₁ and the outer panel W ₂ are superposed on the work placing portion 13 of the lower die 11. The upper die 12 is lowered together with the press ram.
By the lowering of the upper die 12, first, the flat surface 24a of the hem blade 24 is engaged with the bending flange w of the outer panel W ₁ , and the hem blade 24
The reaction force of the bending flange w is applied to. At this time, as shown in FIG. 3, the reaction force F of the bending flange w is converted into a downward component force F ₁ and a lateral component force F ₂ . Therefore, the spring force of the coil spring 25 is set to be slightly larger than the lateral component force F ₂ , and as a result, the bending of the bending flange w, that is, prehemming proceeds, and the bracket 22 is moved to the horizontal shaft 24. Is oscillated in a clockwise direction (FIG. 1) about the fulcrum, and as shown in FIG. 2, the initial pre-hemming position is moved to the A ₁ position and further to the A ₂ position along the bending locus of the bending flange w.

Then, when the hem blade 24 is displaced to the A ₂ position, the bracket 22 contacts the second stopper 29 and its swing is restricted. After that, as the upper die 12 descends, the hem blade 24 descends along the pressing direction P to the A ₃ position, during which the bending flange w is further bent by the inclined surface 24b of the hem blade 24 and the main hemming proceeds. Then, finally, the end portion of the inner panel W ₂ is sandwiched between the outer panel W ₁ , and the hemming process is completed.

5 and 6 show a second embodiment of the present invention. The feature of the second embodiment is that
A T-shaped bracket 31 is used as a bracket for supporting the hem blade 24, and one end of the bracket 31 is attached to the horizontal shaft 24.
And the other end of the bracket 31 is urged by a coil spring 32 composed of a compression spring, and the first stopper 28 is extended from the upper mold 12 to a lower end of a support arm 33. The second end of the bracket 31 is supported by the second stopper 29, and the second stopper 29 is set between the horizontal shaft 24 and the first stopper 28. The point is that they are brought into contact with each other.
In these figures, the same parts as those shown in FIG. 1 are designated by the same reference numerals.

In the second embodiment, the hem blade 24 is positioned in the initial pre-hemming posture by the urging force of the coil spring 32, and the hem blade 24 is first moved to the outer panel W ₁ in accordance with the lowering of the upper die 12. Engage the bending flange w,
Then, the bracket 31 swings against the biasing force of the coil spring 32, and the pre-hemming and the main hemming continuously proceed in the same manner as in the first embodiment (FIG. 2).

[0019]

As described above in detail, according to the hemming apparatus of the present invention, the preheming and the main hemming are performed by utilizing the simple swinging motion of the bracket that supports the hem blade. Since it can be made continuous, it is possible to reliably prevent the occurrence of problems such as buckling and deformation, and the structure is remarkably simple, resulting in a significant improvement in assembly and a significant reduction in equipment costs. Produces the effect of

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a hemming processing apparatus according to the present invention.

FIG. 2 is a front view showing a progress state of hemming processing in the first embodiment.

FIG. 3 is an explanatory diagram for explaining a processing theory by the present hemming processing apparatus.

FIG. 4 is a cross-sectional view showing the overall structure of a hemming processing apparatus according to the first embodiment.

FIG. 5 is a front view showing a second embodiment of the hemming processing apparatus according to the present invention.

FIG. 6 is a front view showing the final stage of hemming processing in a second embodiment.

FIG. 7 is a front view schematically showing a mode of use of a conventionally commonly used hemming device.

[Explanation of symbols]

11 Lower mold 12 Upper mold 13 Work placement part 21 Horizontal shaft 22 Bracket 24 Hem blade 25 Coil spring (tensile spring) 28 Stopper 29 Stopper 31 Bracket 32 Coil spring (compression spring) W ₁ Work W ₂ Opposite work w Bending flange

Claims (1)

[Claims] 1. A bracket is attached to the upper die so as to be swingable about a horizontal axis as a fulcrum, and a hem blade is supported on the bracket so as to engage with a bending flange of a work on the lower die as the upper die descends. Between the upper die and the bracket, there is interposed an urging means for urging the bracket to displace the hem blade in a direction opposite to the bending direction of the bending flange, and to the upper die, A hemming apparatus, wherein two stoppers are provided for restricting the swing of the bracket to position the hem blade in an initial pre-hemming posture and a main hemming posture.