JPS5922887Y2 - Opposed hydraulic drawing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an opposed hydraulic drawing apparatus, particularly an opposed hydraulic drawing apparatus for tapered products.

A opposed hydraulic drawing method is known as a method for forming and pressurizing a cup-shaped or container-shaped product from a flat plate.

This method involves filling a die cavity with a liquid such as oil.
- Lower the blank holder from above and pinch the periphery of the blank between it and the die face, then lower the punch inside the blank holder into the die cavity to generate opposing hydraulic pressure on the sealed liquid, and this opposing liquid Pressure brings the blank into close contact with the punch, improving molding accuracy.

By the way, this facing hydraulic drawing method can perform good processing when the product shape is a simple shape such as a straight cylinder, but when the product shape is a simple shape such as a straight cylinder, it can be processed well. There is a problem in that molding defects are likely to occur when the product has a composite shape with a so-called tapered shape.

That is, when forming such a tapered product by the above-mentioned method, a punch 3 having a tapered portion 31 corresponding to the product taper is used as shown in FIGS.
However, if the punch 3 is simply pushed into the cavity 2, the distance l between the punch 3 and the wrinkle holding plate 4' is wide at the initial stage of molding, as shown in Fig. 10C. A blank located in a wide space bulges W due to the opposing hydraulic pressure, and this bulge W becomes excess material at the final stage of molding when the punch 3 presses more, causing wrinkles in the product.

To prevent this, by lowering the opposing hydraulic pressure at the beginning of molding,
A phenomenon occurs in which the blank W is insufficiently wrapped around the punch 3 and the punch shoulder material breaks, and therefore, in any case, it is not possible to form a tapered product with good shape and dimensional accuracy. It is.

The present invention was developed in view of the above-mentioned circumstances, and has a relatively simple structure that uses opposed hydraulic pressure to draw a good tapered shape without causing blank wrinkles or punch shoulder breakage. The purpose is to provide drawing and forming equipment.

For this purpose, the present invention installs a slider whose tip touches the taper of the punch on the bottom surface of the blank holder that sandwiches the peripheral part of the brush and the die face, and the advance of the slider allows the punch and blank holder to be connected at the initial stage of forming. This eliminates the gaps between the blanks and prevents the blank from bulging or protruding.

The present invention will be explained below with reference to the accompanying drawings.

Figures 1 to 7 show an embodiment in which the present invention is applied to a mold device for drawing a tapered shape using opposing hydraulic pressure.
In the drawings, reference numeral 1 denotes a die (hydraulic dome), which has a hydraulic chamber 2 inside its skin for containing a liquid F such as oil.

Reference numeral 3 denotes a punch which is pushed into the hydraulic pressure chamber 2, has a contour corresponding to the shape of the product to be formed, has a tapered portion 31 on at least one side that slopes upward from the top surface of the punch, and has an inner press. 7, it is raised and lowered with a predetermined stroke length.

Numeral 4 is a blank hole surrounding the circumference of the punch 3, which is attached to the outside and is fixed to the lower part of the press (wrinkle press) 8, which is raised and lowered independently of the inner press 7, and which is attached to the die face. 11, and a blank W is sandwiched between the two.

This configuration is similar to a conventional drawing device, but
In the present invention, a recessed part 5 whose front end communicates with the punch insertion window 9 is first formed on the lower surface of the blank holder in a region facing the digging part 31 of the punch 3. It has a guide groove 51.51 which reaches the punch insertion window 9 from the side surface of the case or ends at a portion of the hand Ai1 slightly from the punch insertion window.

Although the force-id groove is shown as a right-angled groove in the drawing, it goes without saying that any other groove may also be used.

A slider 6 having a protrusion 62.62 that is slidably fitted into the force guide groove 1.51 is attached to the recess 5, and the slider 6 has a lower surface 63 aligned with the lower surface 41 of the blank holder. In addition, the punch 3
A tip portion 6 whose shape and angle match that of the tapered portion 31 of
1, and the tip portion 61 has protrusions 64 and 64 at both ends in the width direction that match the corner radius of the punch taper portion 31, and these protrusions 64, 64 and the tip portion 61 form a punch taper. It is configured to be in close contact with the section 31.

In the embodiment described above, both the slider 6 and the punch 3
The branch piece 12 is automatically moved by the punch 3 as the punch enters, and in this embodiment, the branch piece 12 is fixed to the outer press 8 or the blank holder 4 in order to improve the close contact with the taper part 31 of the punch. , a slider 6 is attached to this branch 12,
A member 13 is attached to the bullet 13 for constantly pressing and biasing the slider 6 in the direction of the punch, and a piece 14 for the swivel and collar is attached to the rear of the slider 6.

In the embodiment shown in FIG. 7, a similar mechanism is provided on the die side.

The elastic body may be a spring, and the guide groove 51,
When 51 also serves as a stopper, the stopper piece is unnecessary.

In this embodiment, since the tapered portion 31 of the punch 3 is located at one location, the slider 6.6' is attached only to one side. However, in the case where the tapered portion 31 is formed on two back sides The recesses 5, 5' and the slider 6, 6' are arranged accordingly.
It increases the

Since the opposed hydraulic drawing mold device according to the present invention has the above-described configuration, when drawing a tapered product, the hydraulic chamber 2 of the die 1 is filled with liquid, and the blank W is placed in the die. The blank holder 4 is lowered by operating the outer press 8 with the cellar lt placed on the face 11 and then the inner press 7 stopped.

At this time, the slider 6 is inserted into the guide and guide grooves 51 and 51 of the recessed portion 5.
Since the tip part 61 protrudes into the punch insertion window 9, it descends along with the blank holder, and the blank W falls between the die face 11 and the blank holder 4. It is sandwiched by the lower surface 41, and a portion is sandwiched between the lower surface 63 of the slider 6 and the die face 11.

This state is shown in FIG. 1. Next, when the inner press is activated to lower the punch 3, the top surface of the punch 3 enters the punch insertion window 9 of the blank holder 4, and almost synchronously, the taper portion 31 The tip 61 of the slider 6 starts to come into contact with
Further, as the punch 3 descends, the slider 6 retreats while coming into close contact with the tapered portion 31 due to the thrust force of the punch 3, and in this state, the top surface of the punch comes into contact with the blank W.

As the punch 3 continues to descend further, an opposing hydraulic pressure is generated in the cavity due to the press fit of the punch 3, and as shown in FIGS. 6 and 7, the blank W is wrapped around the punch 3 due to the opposing hydraulic pressure, but at this time As mentioned above, the slider 6 protrudes between the punch taper part 31 and the blank holder 4, and since its tip 61 is in close contact with the punch taper part 31, the blank W is pressed by the lower surface 63 of the slider 6. Draw forming progresses with the blank not bulging and properly adhering to the punch shape.

When the drawing process is completed in this way, the slider 6
is retreated by the thrust force of the punch 3, and automatically advances again when the outer press 8 is raised to take out the product.

According to the present invention described above, a die 1 having a hydraulic pressure chamber 2 and a tapered punch 3 to be pushed into the hydraulic pressure chamber 2 are provided.
and a vertically movable blank holder 4 that presses the blank W between the punch outer periphery and the die face. , guide groove 51.
51, and in this recessed part 5, a lower surface is aligned with the blank holder lower surface 41, a tip part 61 that contacts the tapered part 31 at the longitudinal end, and a protrusion part 64, 64 that contacts the taper part corner. The formed slider 6 is slidably attached to the protrusions 62.62 on both sides and the guide groove 51.51, and the blank holder or outer press 8 is provided with an elastic body that constantly presses and urges the slider 6 into the blank holder. 13 is installed, and the tapered part 3 is removed during facing hydraulic drawing forming.
The slider tip 61 and the protruding portion 64.6 are attached to the tapered portion 31 while the slider lower surface 63 is in contact with the blank corresponding to No. 1.
4 in contact with each other to perform opposed hydraulic forming while suppressing the bulge of the blank due to opposed hydraulic pressure.By taking advantage of the advantages of opposed hydraulic forming, the opposed hydraulic pressure is increased in the early stage of forming and the blank is punched. Moreover, it is possible to effectively avoid the bulging of the blank due to hydraulic pressure and the occurrence of body wrinkles due to this, which were problems when forming tapered products using opposed hydraulic pressure, and to produce tapered products with good shape and precision. can be obtained easily.

Furthermore, despite having such characteristics, the slider 6, which is a blank bulge prevention means, is held by the guide groove 51.51 and the protrusion 62.62 in the recessed part 5 on the lower surface of the blank holder that is raised and lowered by the outer press, and the elastic body 13 Since the blank is energized by the press, it is possible to automatically prevent the blank from bulging by simply raising and lowering the outer press. This also simplifies the structure and operation, since no hydraulic cylinder or hydraulic circuit is used. This method has excellent effects, such as being easily implemented in existing opposed hydraulic molding equipment.

[Brief explanation of drawings]

Fig. 1 is a vertical side view showing an embodiment of the opposed hydraulic drawing device according to the present invention, Fig. 2 is a plan view of the blank holder in Fig. 1, and Fig. 3 is a partially cutaway longitudinal section thereof. 4 is a plan view showing an embodiment of the slider according to the present invention, FIG. 5 is a sectional view taken along the line ■-■ in FIG. Side view, Figure 7 is the rear view, Figure 8 a, l),
c is a longitudinal sectional side view showing a molding state by a conventional opposing hydraulic molding device. 1... Die, 2... Hydraulic pressure chamber, 3... Punch, 4...
... Blank holder, 5 ... Recessed part, 6 ... Slider, 8 ... Outer press, 13 ... Elastic body, 31 ...
...Tapered part, 41...Blank holder bottom surface, 51.
...Guide groove, 61...Tip, 62...Protrusion, 6
3... Lower surface, 64... Protruding part.

Claims (1)

[Scope of utility model registration request] A counter hydraulic system comprising a die 1 having a hydraulic pressure chamber 2, a tapered punch 3 that is pushed into the hydraulic pressure chamber 2, and a blank holder 4 that can be raised and lowered to press a blank W between the die face and the outer periphery of the punch. The drawing device includes a punch 3.
A recessed portion 5 having a guide groove 51° 51 is formed on the lower surface of the blank holder in a region facing the tapered portion 31 of the recessed portion 5, the lower surface of which is aligned with the lower surface 41 of the blank holder,
The slider 6 has a tip 61 in contact with the tapered part 31 at the longitudinal end and a protrusion 64.64 in contact with the corner of the taper part.
1, and an elastic body 13 is attached to the blank holder or outer press 8 to constantly press and bias the slider 6 into the blank holder. The slider tip 6 is attached to the tapered portion 31 while bringing the slider lower surface 63 into contact with the slider tip 6.
1 and the protrusions 64, 64 are brought into contact with each other to perform forming while suppressing the bulge of the blank due to the opposing hydraulic pressure.