JPS6247096B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a press molding die, and particularly to improving the release between a cylindrical molded product and the die.

Generally, when manufacturing a cylindrical product with one end closed using high-strength aluminum alloy, warm press forming is sometimes used, and the mold used for this press forming is A lower mold having a mold surface for molding the inner peripheral surface and the inner surface of the end surface to be closed (hereinafter referred to as the bottom plate), and an upper mold for molding the outer surface of the bottom plate of the molded product and the inner peripheral surface of the cylinder protruding from the bottom plate. It may be equipped with.

Conventionally, when releasing a molded product from such a press molding die, as the upper die rises relative to the lower die, a dowel pin inserted into the center of the lower die rises relative to the lower die. The method used was to push up the inner surface of the bottom plate of the molded product with the upper end of the knock pin to release it from the mold (see Figure 1).

However, in this conventional mold release method, the molded product is pushed out only by the dowel pins, so the pushing up force is concentrated at the center of the bottom plate.
There was a drawback that deformation occurred in the bottom plate and the cylindrical side plate.

An object of the present invention is to provide a press molding die that can be released while maintaining a predetermined shape by pulling up the cylindrical side plate of a cylindrical molded product.

The present invention provides an annular notched groove having an interrupted portion in a mold surface for molding a part of the inner peripheral surface of the cylindrical side plate in an upper mold as a means for pulling up the cylindrical side plate of a cylindrical molded product. A protrusion is formed to engage the cylindrical side plate and the upper mold in this notched groove, the cylindrical side plate is pulled up, and after the mold is released, the protruding portion remaining in the notched groove is blown away with compressed air. It is designed to be released from the mold.

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

In FIG. 1 showing an embodiment of the present invention, this press molding die 1 is a molded product 2 having a substantially cylindrical shape with one end closed, which is warm press-formed using a high aluminum alloy. The molded product 2 has a cylindrical main side plate 2A, a bottom plate 2B, and a substantially cylindrical bottom side plate 2C. Press molding mold 1
is equipped with a pedestal 3, and a container 4 is placed on the pedestal 3.
and a lower mold 5 are provided. The container 4 is formed with a substantially stepped cylindrical mold surface 4A formed on the outer peripheral surfaces of the main side plate 2A and bottom side plate 2C of the molded product 2, and the lower mold 5 is formed on the inner surface of the main side plate 2A of the molded product 2. A substantially cylindrical mold surface 5A is formed by molding the peripheral surface, the circular annular end surface, and the inner surface of the bottom plate 2B. A dowel pin 6 is slidably fitted into the center of the lower mold 5. One end of the dowel pin 6 abuts the center of the bottom plate 2B of the molded product 2, and the other end fits into the pedestal 3. It is in a prominent state. The knock pin 6 is slidably driven with respect to the lower mold 5 by a driving means (not shown) provided below the pedestal 3, so that the bottom plate 2B of the molded product 2 can be pushed up. At the top of the mold surface 4A of the container 4,
An upper mold 7 that is pressed down by a ram of a press machine (not shown) is fitted so as to be able to move forward and backward, and the outer shape of the bottom plate 2B of the molded product 2 and the inner peripheral surface of the bottom side plate 2C are formed in the lower part of the upper mold 7. A mold surface 7A is formed by molding a circular annular end surface.

As shown in FIGS. 1 to 4, on the outer circumferential surface of the mold surface 7A of the upper mold 7, there is a cutout groove 8 having a right triangular cross section, with its right angle disposed on the outer circumferential surface on the side of the bottom plate 2B. The notch groove 8 is formed in an annular shape, and the cutout groove 8 is provided with interrupted portions 9, which partially cut out the annular shape of the groove 8, at two positions facing each other with the center sandwiched therebetween. Therefore, on the inner peripheral surface of the bottom side plate 2C of the molded product 2, the engaging protrusion 10 is formed in the notch groove 8.
As a result, it is formed into a substantially annular band shape that is separated at two locations of the pair of interrupted portions 9, 9. Compressed air holes 11 are formed in the upper mold 7, and jet ports 12 of the air holes 11 are formed at the bottoms of the notch grooves 8 at the center of the pair of interrupted portions 9, 9. has been done. An unillustrated inlet of the compressed air hole 11 is connected to an unillustrated compressed air supply source.

In FIG. 1, reference numeral 13 denotes a barrier plate provided on the outer end surface of the container 4, which has the function of slidingly contacting the outer circumferential surface of the molded product 2 and suppressing its rise.

The effect regarding mold release in the press molding die having the above configuration will be explained.

When the knock pin 6 and the upper mold 7 are raised at the same time, the molded product 2 moves the protrusion 10 formed on the inner peripheral surface of the bottom side plate 2C into the notch groove 9 while the bottom plate 2B is pushed up by the knock pin 6. It is held in a state where it is engaged with the right-angled shoulder and is pulled up by the upper mold 7,
Mold surface 4A of container 4 and mold surface 5A of lower mold 5
It is gradually released from the mold. When the outer peripheral surface of the bottom side plate 2C of the molded product 2 comes into sliding contact with the interference plate 13 as it rises, a difference occurs between the rise of the molded product 2 and the upper mold 7. Due to this difference, the protrusion 1 of the molded product 2
0 and the shoulder of the notch groove 8 of the upper mold 7, the protrusion 10 is sheared by the shoulder of the notch groove 8, and the upper mold is inserted into the notch groove 8. Remains in type 7. Along with this shearing, the upper mold 7 gradually separates from the molded product 2, and the molded product 2
are separated to form the desired molded shape.

Protrusion 10 fitted into notch groove 8 of upper mold 7
Since the annular shape is cut off by the interrupted portions 9, 9, they form a pair of semicircular band shapes. Therefore,
When compressed air is supplied to the compressed air hole 11 of the upper mold 7 and the compressed air is ejected from the pair of jet ports 12, 12, the protrusion 10 is blown away from the inside of the notch groove 8, and the upper mold He will be withdrawn from 7. If the protruding portion 10 is released from the mold in this manner, the upper mold 7 returns to its original moldable state, so that press molding can be performed repeatedly.

According to this embodiment, since the cross-sectional shape of the notch groove is formed into a right-angled triangular shape, the protrusion can be sheared with a small shearing force. In addition, since a pair of interrupted portions are provided at positions directly facing each other in the notched groove, the protruding portion is divided into two parts, and the remaining protruding portion is blown away by compressed air at a small pressure (5 to 6 kg/cm ^{2 ).} It has been confirmed that it can be blown away sufficiently.) In addition, since the mold is released by holding and pulling up the inner peripheral surface of the bottom side plate of the cylindrical molded product, there is no deformation of the cylindrical molded product during mold release, resulting in excellent dimensional accuracy. Precision molded products can be obtained efficiently.

In addition, in the above embodiment, the case where the cross-sectional shape of the notch groove was formed into a right triangle shape was explained.
The shape of the notch groove is not limited to this. Furthermore, if the cutout groove is interrupted at at least one location, the remaining protrusion can be blown away with compressed air. Furthermore, although a cylindrical molded product having a bottom plate on one end surface has been described, the present invention is not limited to this.
For example, it can be applied to press forming of thin-walled cylindrical molded products, molded products that have protrusions in the direction of the cylinder center on the outer or inner circumferential surface of the cylinder (for example, finned drums, compressor casings, etc.). can.

As described above, according to the present invention, a cylindrical molded product can be released from the mold while suppressing deformation, so that a highly accurate cylindrical molded product can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part, Fig. 3 is a partial front view of the upper mold, and Fig. 4 is taken along the line shown in Fig. 3. FIG. 1...Mold for press molding, 2...Molded product, 3...
...cradle, 4...container, 5...lower mold, 6...
Knot pin, 7... Upper mold, 8... Notch groove, 9...
... Intermittent part, 10... Projection part, 11... Compressed air hole, 12... Jet outlet.

Claims (1)

[Claims] 1. In a press molding die equipped with an upper die having a die surface for forming a part of the inner circumferential surface of a cylindrical molded product, a notched groove having an interrupted portion at at least one place on the die surface of the upper die. A press molding die, characterized in that the upper die is provided with a compressed air hole having an outlet opening at at least two locations at the bottom of the notched groove.