JPH0527209Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a bending flange processing die that is provided with an upper curved blade for two-stage bending of a material.

[Conventional technology]

Conventionally, Fig. 4 shows a bending flange processing die in which two stages of bending flanges are formed on a material with one stroke of the ram. After that, at the bottom dead center of the ram (not shown), the material 9 shown by the chain line is inserted into the second stage curved blade 4b and the first stage curved blade 4a of the upper mold curved blade 4' for two-stage bending. This shows an example in which the bending process is completed between the lower die 7 and the lower die 7.

[The problem that the idea attempts to solve]

However, in the case of FIG. 4, the following phenomenon occurs depending on the flange length conditions of the material 9.

That is, in FIG. 5, the second stage curved blade 4b of the upper mold curved blade 4' bends the second stage flange 9b of the material 9 between it and the lower mold 7, and then the upper mold curved blade 4 1 of the material 9 between the first stage curved blade 4a and the lower mold 7.
When the bending process of the step flange 9a is started, the material 9 is subjected to tension in the directions of arrows A and B.

At this time, the second flange 9b of the material 9 is
Since the material 9 is restrained by the second stage curved blade 4b of the upper mold curved blade 4' and the lower mold 7, if a tension exceeding its allowable elongation rate is applied to the material 9, as shown in FIG. 9 is broken at the first flange 9a.

Further, the smaller the roundness (R) of the ridge line of the first stage curved blade 4a of the upper mold curved blade 4', the easier the material 9 will break.

Therefore, in order to prevent the material 9 from breaking, as shown in FIG.
The gap T between the lower mold 7 and the material 9 is expanded by adding Δt to the plate thickness t of the material 9, and the press quality is unavoidably deteriorated due to the waving phenomenon in the second stage flange 9b. Alternatively, as shown in FIG. 8, in order to reduce the elongation rate of the material 9,
Increasing the roundness (R) of the ridge line of the first stage curved blade 4a of the upper mold curved blade 4' and also increasing the roundness (R) of the ridge line of the lower mold 7 degrades the press quality, so no countermeasures are required. The problem is that you don't get it.

Therefore, in order to solve such problems, the purpose of this invention is to process a two-step bent flange of a material in one step without causing wrinkles or cracks.

[Means to solve the problem]

Therefore, this idea solves the above-mentioned problem by maintaining a wide clearance between the lower mold and the second-stage curved blade until the bending flange of the material is processed, and at the bottom dead center of the ram, the second-stage curved blade and the bottom To ensure proper clearance between the mold and the mold, the second stage curved blade is moved by a cam on the bolster, and together with the first stage curved blade fixed to the ram, each stroke of the ram creates a step-like bend in the material. This problem is attempted to be solved by processing the flange.

More specifically, referring to the reference numerals shown in FIG. 1, the ram 1 is provided with a material presser 3 and an upper mold bending blade 4 for two-stage bending of the material 9. In the bending flange processing die for forming a stepped bending flange on the material 9 by the lower die 7 disposed on the upper die curved blade 4 and the bolster 6 at the bottom dead center of The curved blade 4a of the first stage is divided into the curved blade 4a of the first stage and the curved blade 4b of the second stage is fixed to the ram 1, and the curved blade 4 of the second stage is
b is attached to the first stage curved blade 4a via a spring 5 so as to be movable in the left and right direction.
A step-shaped bending flange is formed on the material 9 by bringing the second stage curved blade 4b and the lower die 7 closer together or apart from each other by making them come into contact with a cam 8 fixedly attached to the cam 8. It is.

[Effect]

According to the above-mentioned means, after the material presser 3 restrains the material 9 on the lower mold 7 by lowering the ram 1, the second stage curved blade 4b of the upper mold curved blade 4 presses the second stage of the material 9. At the same time, the flange 9b of the flange 9b is slightly bent, and at the same time, the second stage curved blade 4b contacts the cam 8 fixed to the bolster 6, and while compressing the spring 5, the second stage curved blade 4b is directed toward the lower mold 7. By moving close to each other in the left-right direction, at the bottom dead center of the ram 1, the second-stage curved blade 4b, together with the first-stage curved blade 4a, connects the second-stage and first-stage flanges 9b, 9a of the material 9. Complete the bending process.

Further, when the ram 1 is raised after completing step-like bending and flange processing on the material 9, the second-stage curved blade 4b is separated from the lower die 7 in the left-right direction by the spring force of the spring 5.

〔Example〕

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

The drawings from FIG. 1 to FIG. 3 show an embodiment of this invention, and as can be seen from FIG.
A first stage curved blade 4a forming an upper mold curved blade 4 for two-stage bending is fixed to the ram 1.

A second stage curved blade 4b is attached to the first stage curved blade 4a so as to be movable in the left and right direction via a spring 5. In other words, the upper mold curved blade 4 is attached to the first stage curved blade 4a. The curved blade 4b of the second stage is formed separately.

Further, a lower die 7 and a cam 8 are fixed to the bolster 6, and a step portion 7a for bending the first flange 9a of the material 9 is formed on the lower die 7. The cam 8 has the second stage curved blade 4b.
An inclined portion 80 having the same slope as the oblique side portion 40 is formed.

Therefore, when the oblique side portion 40 of the second stage curved blade 4b comes into contact with the inclined portion 80 of the cam 8 fixed to the bolster 6 as shown in FIGS. 2 and 3 as the ram 1 descends, , the oblique side 40 of the second stage curved blade 4b is the cam 8
The second-stage curved blade 4b slides on the inclined portion 80, and moves toward the lower die 7 in the left-right direction while compressing the spring 5.

In detail, as shown in Figure 2, the ram 1
After the material presser 3 restrains the material 9 on the lower mold 7 by lowering the material 9, the second stage curved blade 4b of the upper mold curved blade 4 for two-stage bending presses the second stage flange 9b of the material 9.
bend it slightly.

Next, when the first-stage curved blade 4a shown in FIG. 2 starts bending the first-stage flange 9a of the material 9, the material 9 is subjected to tension in the directions of arrows A and B. At this time, the second stage curved blade 4b has a spring 5
Since the flange 9b of the second stage, which is the end of the material 9, is not restrained and smoothly slides in the direction of arrow C, the material 9 elongates. The ratio is reduced, and cracking or breakage of the material 9 can be prevented.

Thereafter, when the ram 1 further descends, as shown in FIG. The oblique side 40 of the curved blade 4b is connected to the cam 8
While sliding on the inclined part 80 of the ram 1 to compress the spring 5, the second stage curved blade 4b moves toward the lower mold 7 in the left and right direction, and at the same time, as the ram 1 moves toward the bottom dead center, the lower mold 7 , the distance between them approaches the appropriate value, and the ram 1 reaches the bottom dead center as shown in FIG.

In this way, at the bottom dead center of the ram 1 shown in FIG. 4b completes the bending of the second and first flanges 9b and 9a of the material 9 together with the first stage curved blade 4a.

In addition, when the ram 1 is raised after completing step-shaped bending flange processing of the material 9, the second stage curved blade 4b
is moved in a direction away from the lower die 7 by a predetermined distance by the spring force of the spring 5, and waits for the next step.

[Effect of idea]

As mentioned above, this idea consists of dividing the upper curved blade into the first and second stage curved blades, and forming the second stage curved blade into one stage.
It is possible to move in the left and right direction with respect to the curved blade of the second stage.
Since the curved blade of the step and the lower mold are made to be close to each other or separated, the roundness (R) of the ridge line of the curved blade of the first step of the upper mold curved blade is made small, and the steps can be completed with one stroke of the ram. When processing a two-stage bent flange, the elongation rate of the material is reduced to prevent material breakage, and the roundness of the ridgeline of the upper die curved edge is reduced, making it easier to assemble the press-formed product into a vehicle. The quality of appearance can be improved.

Another advantage is that even if the second stage flange of the material is at a negative angle with respect to the pressing direction, it can be bent.

[Brief explanation of drawings]

The drawings from FIG. 1 to FIG. 3 show an embodiment of this invention. 2 and 3 are cross-sectional views showing the approaching state of the upper die curved blade and the lower die during the descent of the ram, respectively, and the drawings from FIGS. 4 to 6 show one conventional press process. FIG. 7 is a cross-sectional view showing the completed state of pressing of another conventional example,
FIG. 8 is a cross-sectional view showing a completed pressing state of still another conventional example. 1... Ram, 3... Material presser, 4... Upper mold curved blade, 4a... 1st stage curved blade, 4b... 2nd stage curved blade, 5... Spring, 6... Bolster, 7 ……
Lower mold, 8... cam, 9... material.

Claims (1)

[Scope of utility model registration request] The ram is provided with a material presser and is also provided with an upper mold curved blade for two-step bending of the material, and at the bottom dead center of the ram, the upper mold curved blade and the lower mold disposed on the bolster cause In a bending flange processing die that processes a stepped bending flange on a material, the upper curved blade is divided into a first stage curved blade and a second stage curved blade, and the first stage curved blade is fixed to the ram. The second stage curved blade is attached to the first stage curved blade via a spring so that it can move in the left and right direction, and the second stage curved blade is fixed to the bolster by the lowering of the ram. This bending flange processing mold is characterized in that a step-like bending flange is formed on a material by bringing the gap between the second stage curved blade and the lower mold closer to each other or further apart by bringing the second stage curved blade into contact with the lower mold.