JPS6116916Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a mold used in a vertical die-casting machine in which a plunger for pressurizing molten metal and pistons of a counter on the pressure-receiving side are disposed above and below.

More specifically, the pressure-receiving side counter is formed to have a smaller diameter than the pressure-applying side plunger, and the upper mold upper body is provided with a separation surface between the stamp part and the runner part on the upper mold lower body. The present invention relates to a die-casting mold configured such that the upper mold body is separated before the lower mold body, so that casting can be performed from a portion with a smaller diameter than the plunger diameter.

In a vertical die casting machine that has a plunger that pressurizes the molten metal and a counter piston on the pressure receiving side that receives the molten metal arranged above and below, the cross-sectional area of the plunger side is larger than the opening area of the cast product (molded product), such as a vehicle. When casting a hub part for a wheel, the stamp part that is above and connected to the runner part when the mold is opened becomes an undercut. For this reason, it is difficult to release the mold using the dividing surface of the upper and lower molds of the normal upper and lower mold type, and if this is forced, the molded product may be damaged, and in practice, smooth mold release is not possible. On the other hand, the plunger on the pressurizing side requires thermal considerations such as storing the molten metal in the molten metal sleeve and keeping it warm, and even if the opening area of the temporary molded product is small, it is not possible to reduce the cross-sectional area to accommodate this. The cross-sectional area becomes larger than the predetermined cross-sectional area. Therefore, the above-described casting using a vertical die-casting machine cannot be practically adopted because of problems with mold release.

The inventors of the present invention have devised the present invention in view of the above problems of vertical die casting machines in casting, and to effectively solve these problems.

The purpose of this invention is to use a vertical die-casting machine in which molten metal is cast using a pressure-side plunger and a pressure-receiving counter piston, which are arranged above and below. Then, arrange the dividing surfaces of the upper and lower molds to be the interface between the stamp part and the runner part, and move the upper body of the upper mold upward in advance to cut the stamp part from the runner part. To provide a die-casting mold in which a space is formed, cutting is performed therein, and then an upper mold lower body and a lower mold are opened.

Therefore, the purpose of the present invention is to enable cast molding from the small diameter part even when the plunger has a large diameter and the runner part etc. has a smaller diameter. To provide a die casting mold which can be molded without any damage, can be easily and reliably taken out after molding without damaging the molded product, and can achieve the above with a simple structure.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory longitudinal sectional view of a mold according to the present invention, in which the mold 1 consists of a lower mold 2 and an upper mold 8.
It consists of a frame-shaped main body 3 and a lower mold core 4 which is internally held within the main body 3. A molding groove 5 is provided on the upper surface of the lower mold core 4 to form a molding space during mold matching, and the lower mold main body 3 is supported by a base 6 via a support member 7.
It is a fixed type including the core 4.

The upper mold 8 consists of a frame-shaped upper mold main body 9 and an upper mold core 10 that is internally held in this, and a center core 11 is installed in the upper mold core 10 through a vertical hole 10a. A molding groove 12 is formed on the lower surface of the cores 10 and 11. The figure shows an example of die-casting a vehicle wheel hub, in which a projection 4a is formed on the center of the lower mold core 4 to form an axle insertion opening, while a projection 4a is formed on the center of the center core 11. A runner hole 11a whose diameter becomes smaller upward is formed, and this hole 1
The lower part 11b of 1a is formed in a huge size corresponding to the aforementioned projection 4a, and the lower mold 2 and upper mold 8 are joined at the groove part to form a mold matching surface A, that is, a mold dividing surface. .

The center core 11 has a support flange portion 11c on its upper outer periphery, and the flange portion 11c is attached to the upper mold core 1.
The upper part of the central core 11, which protrudes above the flange 11c and includes the flange portion 11c, is fitted into the step hole 9a of the upper mold body 9 and held by the upper mold 8.

An upper mold upper body 13 is disposed on the upper mold main body 9 with its upper and lower surfaces serving as dividing surfaces B. Upper body 1
3 is connected to the upper base plate 14 via a support member 15, and the lower part of an injection sleeve 16 is fitted into the center of this 13 through a vertical hole 13a, and the diameter D of this sleeve 6 is the same as the opening of the molded product. The protrusion 4a forming the part
is larger than the diameter _D1 of the runner portion 11a, and is also sufficiently larger than the diameter of the runner portion 11a. A pressurizing plunger piston 17 is slidably inserted into the sleeve 16.
A protrusion 17a smaller in diameter than the runner portion 11a is formed at the lower end of the plunger 17. In addition, 18 in FIG. 1 is an ejectopine.

A counter piston 19 on the pressure receiving side is slidably fitted in the center of the lower mold 2 through the vertical holes 4b and 3a, and the piston 19 faces the center of the protrusion 4a of the lower core 4. The upper surface of the projection 4a is set flush with the upper edge of the projection 4a. And the sleeve 20 is the lower die main body 3
The upper part is supported by the hole 3a.

The main body 9 of the upper mold 8 and the upper main body 13 are connected as shown in FIG. 4. That is, the support pin 21 is suspended from the upper body 13, the pin 21 is fitted into the stepped vertical hole 22 provided in the main body 9, and the flange portion 21a at the lower end of the pin 21 and the small diameter portion 22a of the vertical hole 22 are not engaged. Make it stop. Therefore, the upper body 13 has a predetermined stroke h.
When moved upward, the flange portion 21a is caught on the vertical hole small diameter portion 22a, and the upper die 8 is configured to move upward from the state shown in the figure.

The counter piston 19 moves upward and the runner section 11
a, and inject and store the molten metal in the sleeve 16,
The plunger 17 is lowered to pressurize the molten metal. When a predetermined pressure is applied, the counter piston 19 moves downward to the position shown in FIG. 1, and as the plunger 17 continues to move downward, the molten metal is press-fitted into the molding space between the upper and lower molds, and a cast molded product W is obtained. A runner portion W ₁ is integrally molded above the center of the molded product W so that the diameter becomes smaller toward the top.
Furthermore, a stamp part W ₂ is integrally formed above the runner part W ₁ and occupies the lower part of the sleeve 16 . The stamp part _W2 is narrowed at the boundary with the runner part _W1 , and the lower surface of the stamp part _W2 is connected to the upper die lower body 9 and the upper die upper body 13.
This is the undercut part _W3 facing the boundary line between the two.

Next, to explain mold opening, that is, mold release, after the molten metal has solidified and cooled in the state shown in FIG. 1, the base plate 14 is moved upward. As a result, the upper mold upper body 13 integral therewith moves upward together with the sleeve 16, and the bodies 9 and 13 are separated from the dividing plane B. In this case, in order to be divided from the dividing plane B, the mold release resistance between the cast molded product and the mold at the molding groove 12 part and the upper mold lower body 9 upper mold core 1
0, the weight of the center core 11 is expected, but at the same time as the base 14 is moved upward, the eject pin 1
8 and pushing down the upper surface of the lower mold main body 9 can also be forcibly divided.

As a result, the stamp part W ₂ is exposed to the space, but the upward movement of the base 14 is stopped just before the stroke up to the stroke h mentioned above, and the stamp part W 2 is attached to a part of the casting machine or the main mold including the bases 6 and 14. The stamp part W ₂ and the runner part W ₁ are separated from each other by external force from the hydraulic cylinder 23 or the like, so that the molded product W is not affected.

In order to reduce the separation force and the amount of remelted material at this time, the protrusion 17a at the lower end of the plunger piston contributes. This state is shown in FIG.

The runner part is damaged by external force from the hydraulic cylinder 23, etc.
When W ₁ and the stamp part W ₂ are separated and it is confirmed that the external force has returned to the predetermined waiting place, the base 14
moves upward again, that is, the upper die upper body 13 moves upward, and when the stroke h described above is reached, the upper die 8 moves upward, and the upper die 8 is separated from the lower die 2 from the dividing surface A, and the stamp part Since W ₂ is separated, the mold opens smoothly and has no effect on the molded product W. This is shown in Figure 3.

In this way, the upper body 13 of the upper mold moves upward to form a space for separating the stamp part, and the stamp part is separated by external force, and the upper mold 8 and the lower mold 2 are opened. The mold can be opened smoothly and the molded product can be taken out without damaging the mold.

Although the illustrated embodiment has been described in detail above, the molded product is not limited to the above example and may be any arbitrary one, and the delay operation mechanism of the upper die upper body 13 and the upper die 8 is not limited to the above embodiment and may be arbitrarily implemented.

As is clear from the above, according to the present invention, even when casting is performed through a small diameter part such as a runner part smaller than the plunger diameter in a vertical die casting machine, the stamp part can be moved by the two-stage operation of the upper die. The upper and lower molds can be opened smoothly and the molded product can be taken out without damaging the molded product by separating it with external force. It is possible to mold any molded product that needs to be provided.

In addition, the upper mold is constructed in two stages so as to perform a delay operation, and a stamp part,
Since the boundary line of the runner section is made to face, the structure is simple and the above can be planned, and it is highly practical.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal cross-sectional view of the molding state, Fig. 2 is a view of the upper mold upper body moving upward and the stamp part separated, and Fig. 3 is the upper mold and the lower mold. FIG. 4, which shows the mold in an open state, is an embodiment of the interlocking mechanism of the upper mold. In the drawings, 1 is a mold, 2 is a lower mold, 8 is an upper mold, 9 is a lower body of the upper mold, 13 is an upper body of the upper mold, 17 is a pressure plunger, and 19 is a pressure receiving counter piston.

Claims (1)

[Scope of Claim for Utility Model Registration] In a vertical die-casting machine consisting of an upper die and a lower die, in which molten metal is cast using pistons of a pressure plunger and a pressure counter arranged above and below, the upper die is the upper die and the lower die. a main body, and a boundary surface between a stamp part and a runner part is formed on a dividing surface of the upper and lower mold bodies of the upper mold, and after the upper body of the upper mold is moved upward in advance, a drive device is provided for moving the lower body of the upper mold upward, and when the drive device moves only the upper body of the upper mold upward, the drive device advances into a space between the upper body and the lower body and is exposed in the space. A die-casting mold characterized by being provided with a stamp section separation device for separating the stamp section from the runner section.