WO2004004949A1

WO2004004949A1 - Die cast mold

Info

Publication number: WO2004004949A1
Application number: PCT/JP2002/006739
Authority: WO
Inventors: Narihiko Ikawa; Yoshio Fujita; Yoshiharu Yoshida
Original assignee: Kabushiki Kaisha Toyota Jidoshokki
Priority date: 2001-05-10
Filing date: 2002-07-03
Publication date: 2004-01-15
Also published as: JP2002331346A; CN1638894A

Abstract

A die cast mold capable of increasing the positional accuracy of a going in/out member to correctly determine the flow channel area of a gate. A die cast mold (21) has a first mold (22) and a second mold (23). The first mold is provided with a cylinder (24) through which a gate (31) extends. A rod (29) is disposed in the cylinder in such a manner that it is capable of making stroke motion. The gate consists of a main flow channel portion (32) and a smallest flow channel portion (33). The smallest flow channel of the gate consists of a smallest flow channel portion defined by the end surface (34) of the rod and the concave surface (35) of a mating surface (P) when the rod abuts against the mating surface (P).

Description

TECHNICAL FIELD The present invention relates to a die casting die used for a PF method. 2. Description of the Related Art Generally, when a solid is made of aluminum or the like, a die casting method is used in which molten metal in a sleeve is extruded by a plunger tip provided at the tip of an injection rod and injected into a cavity.

FIG. 7 shows a die casting die used in the conventional die casting method disclosed in Japanese Patent Application Laid-Open No. 9-993354. The die 1 for die casting includes a male mold 2 and a female mold 3. As shown in FIG. 7, when the male mold 2 and the female mold 3 are closed, the cavity 6 is formed by the concave portion 4 formed in the male mold 2 and the concave portion 5 formed in the female mold 3. You. A gate 7 communicates with the cavity 6, and the gate 7 communicates with the interior of the sleep 9 via a flow path 8. In the sleeve 9, a plunger tip 11 provided at a tip end of the injection rod 10 is housed so as to be able to stroke. The female mold 3 is provided with a gate cylinder 12. An access member 13 is accommodated in the gate cylinder 12 so as to be able to enter and exit the gate 7. In the die-casting method using the die-casting die configured as described above, inert gas such as nitrogen (contained in the air) that exists in the sleep or in the cavity does not react with the molten metal but bubbles in the solid. In order to prevent the deterioration of the quality of animals caused by remaining as a product, a method called the law is adopted. In other words, the PF method is a die casting method in which the air in the cavity is replaced with an active gas such as oxygen, and then a molten metal such as aluminum is poured into the cavity. Specifically, oxygen is sent into the cavity 6 as an active gas, and the air inside the cavity 6 is replaced with oxygen. Then, the plunger tip 11 is stroked to feed the molten metal in the sleeve 9 into the flow path 8. At this time, the entrance / exit member 13 is projected from the gate 7 and the flow area of the gate 7 is reduced, so that the molten metal injected into the cavity 6 from the gate 7 becomes a mist and becomes oxygen and react. This can prevent bubbles from remaining in the animal. Then, when the pressure of the molten metal in the cavity 6 and the gate 7 increases, and the pressure of the molten metal in the sleeve 9 becomes a certain value or more, the access member 13 is moved out of the gate 7 to release the gate. The flow path area of 7 is enlarged, and the molten metal in the sleeve 9 is pressed by applying pressure to the molten metal in the cavity 6. In this way, by applying a sufficient pressure to the molten metal, it is possible to produce an animal that does not generate bow nests.

In the PF method as described above, it is important to realize a gate passage area as expected in order to produce a material that does not cause shrinkage cavities. However, in the above-described conventional die-casting mold, the determination of the flow path area of the gate 7, particularly the determination of the minimum flow path area, depends on the stroke operation of the access member 13. For this reason, in order to maintain the accuracy of determining the flow path area of the gate 7, it was necessary to increase the positioning accuracy of the access member 13. SUMMARY OF THE INVENTION It is an object of the present invention to provide a die casting die capable of increasing the positioning accuracy of an access member and accurately determining the flow passage area of a gate.

In order to achieve the above-mentioned object, the present invention according to claim 1 is a die-casting mold for manufacturing a metal by injecting a molten metal from a gate into the cavity while replacing the air in the cavity with an active gas. , Comprising a cylinder through which a gate penetrates, and a port movably accommodated in the cylinder to adjust a flow path area of the gate, wherein an end face of the port and a bottom face of the cylinder abut. A minimum flow path defining portion is provided on the end face and the bottom face so that sometimes the minimum flow path of the gate is formed between the end face and the bottom face.

In this die casting mold, the minimum flow path of the gate is It is determined when the bottom of the solder comes into contact.

According to a second aspect of the present invention, there is provided the die-casting mold according to the first aspect, wherein the mold includes a first mold and a second mold, and a side surface of the cylinder is the first mold. And one of the second molds, and the bottom surface of the cylinder is a mating surface of the other of the first mold and the second mold.

In this die-casting die, the cylinder is formed by using both the first die and the second die.

According to a third aspect of the present invention, in the die casting mold according to the second aspect, the minimum flow path defining portion comprises an end surface of the rod and a concave surface formed on the mating surface. It is a feature.

In this die casting die, the minimum flow path of the gate is formed by the rod end face and the concave face of the mating face when the rod end face abuts the mating face. According to a fourth aspect of the present invention, in the die casting mold according to the second aspect, the minimum flow path defining portion includes a concave surface formed on an end surface of the rod and the mating surface. It is a feature.

In this die casting mold, the minimum flow path of the gate is formed by the concave surface and the mating surface of the rod end surface when the rod end surface abuts the mating surface. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a gate portion of a die-casting mold according to Embodiment 1 of the present invention. FIG. 2 is an end view of a second mold viewed from an arrow II in FIG.

FIG. 3 is an end view of the first mold as viewed from arrow I I I in FIG. 1,

FIG. 4 is a view schematically showing a state in which a gate is a minimum flow path in the die casting mold according to Embodiment 1 of the present invention,

FIG. 5 is a diagram schematically showing a state in which the gate is in the maximum flow path in the die casting mold according to Embodiment 1 of the present invention, FIG. 6 is a cross-sectional view of a gate portion of a die-casting die according to Embodiment 2 of the present invention. FIG. 7 is a cross-sectional view of a die-casting die used in a conventional die casting method. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment 1

FIG. 1 shows a cross section in a flow direction of a gate portion of a die casting mold according to Embodiment 1 of the present invention. The die 21 for die casting includes a first die 22 and a second die 23. An annular side surface 25 of the cylinder 24 is formed in the second mold 23. The outer surface of the first mold 22 that forms the mating surface PL of the first mold 22 and the second mold 23 constitutes the bottom surface 26 of the cylinder 24. A push 27 is fitted in the cylinder 24. Further, a load 29 that is stroked by a driving device 28 is inserted inside the bush 27 in order to adjust a flow path area of a gate described later. In the present embodiment, a device that generates a driving force by a pressure difference P 1 -P 2 acting before and after the piston 30 is used as the driving device 28.

As shown in FIGS. 1 to 3, a gate 31 that communicates a sleeve (not shown) containing molten metal with the cavity penetrates the cylinder 24. Gate 3 1

The main flow path section 32 with a trapezoidal cross section, and the smallest flow path section with a tubular cross section

It consists of 3 and 3. Also, the bottom surface of the cylinder 24 is formed by the mating surface PL of the first mold 22, and the side surface of the cylinder 24 is formed by the second mold 23, so that the gate 31 is connected to the mating surface PL. It can be formed along. The main flow path portion 32 extends downward from the mating surface PL in the cross section of FIG. 1 at the front and rear portions of the cylinder 24 in the second mold 23. Further, the width of the main flow path portion 32 changes so as to become narrower downward from the mating surface PL. On the other hand,

Reference numeral 33 extends upward from the mating surface PL of the first mold 22 as viewed in the cross section of FIG. In this minimum flow path portion 33, the rod 29 rises as viewed in FIG.

(1) When it comes into contact with the mating surface (PL) of the mold (2), the upper end surface (34) of the rod (29) and the first It is formed between the concave surface 35 formed so as to open downward on the mating surface PL of the mold 22, that is, is defined by the upper end surface 34 and the concave surface 35. Further, since only the concave surface 35 is formed on the mating surface PL of the first mold 22, the minimum flow path portion 33 can be easily formed using an existing mold.

Next, the operation of the die casting die configured as described above will be described. First, oxygen is sent into the cavity (not shown) as an active gas, and the air in the cavity is replaced with oxygen. Then, the molten metal in the sleeve (not shown) is sent into the cavity via the gate 31. At this time, the rod 29 in the cylinder 24 is raised to the uppermost position as shown in FIG. 1 and abuts against the mating surface PL of the first mold 22. As a result, the main flow path portion 32 is closed by the side surface of the rod 29, and the gate 31 becomes a minimum flow path including only the minimum flow path portion 33, as shown in FIG. Therefore, the molten metal passing through the gate 31 is squeezed and atomized, and reacts favorably with oxygen in the cavity. This can prevent bubbles from remaining in the animal. At this time, the rod 29 is not maintained at the intermediate position of the stroke operation as in the conventional case, but is maintained in a state of abutting against the mating surface PL of the first mold 22, so that the positioning is performed. Accuracy can be improved, and the positioned state can be stably maintained. Therefore, the flow path area of the gate can be accurately determined, and the injection state of the molten metal can be set to a state suitable for the reaction with oxygen. Thereafter, when the pressure of the molten metal in the cavity and the gate increases, and the pressure of the molten metal in the sleeve becomes a certain value or more, the rod 29 is moved away from the mating surface PL when the upper end surface 34 of the rod 29 is separated from the mating surface PL. Is slid by the stroke amount S. As a result, the main flow path part 32 is newly opened, and as shown in FIG. 5, the gate 31 has a main flow path part 32 in addition to the minimum flow path part 33 as a flow path for the molten metal. In other words, the channel area increases. Then, by pressing the molten metal in the sleeve, a sufficient pressure can be applied to the molten metal in the cavity through the gate 31 having the increased flow area. As described above, by accurately determining the flow path area of the gate, causing the molten metal to react favorably with oxygen, and applying sufficient pressure to the molten metal, it is possible to produce a material that does not cause shrinkage cavities. .

Embodiment 2 FIG. 6 shows a gate portion of a die casting mold according to Embodiment 2 of the present invention. The die casting die 41 according to the present embodiment also includes a first die 42 and a second die 43 as in the first embodiment. A load 49 is inserted into a cylinder 24 formed in the second mold 43 via a push 27. Further, a gate 51 penetrates the cylinder 24. The gate 51 includes a main channel portion 32 having a trapezoidal channel cross-section and a minimum channel portion 53 having a channel-shaped cross-section. Main flow path portion 32 is formed in the same manner as in the first embodiment. On the other hand, the minimum flow path portion 53 is formed on the upper end face 54 of the rod 49, and extends downward from the upper end face 54 in the cross section of FIG. When the rod 49 rises as shown in FIG. 6 and comes into contact with the mating surface PL of the first mold 42, the minimum flow path portion 53 opens upward at the upper end surface 54 of the rod 49. And the mating surface PL of the first mold 42.

In the die casting die configured as described above, as in the case of the first embodiment, the rod 49 is not maintained at the intermediate position of the stroke operation as in the conventional case. Since it is maintained in a state of abutting against the mating surface PL of the mold 42, the positioning accuracy can be improved, and the positioned state can be stably maintained. Therefore, the flow path area of the gate can be accurately determined, and the injection state of the molten metal can be set to a state suitable for the reaction with oxygen. Further, since only the concave surface 55 is formed on the upper end surface 54 of the rod 49, the minimum flow path portion 53 can be easily formed using the existing mouth. In addition, in the second embodiment, since it is not necessary to form a concave surface defining the minimum flow path portion of the gate in the first mold 42, the size of the minimum flow path portion may be adjusted according to the implementation conditions. When changing the mold, the mold does not need to be changed, and it is sufficient to change the rod that is smaller than that. Therefore, the size of the minimum flow path portion can be changed more easily and inexpensively.

As described above, according to the die casting mold of the present invention described in claim 1, when the minimum flow path of the gate is generated, the rod is maintained in a state of abutting against the bottom surface of the cylinder. Positioning accuracy can be improved, and the positioning state can be stably maintained.

The injection state of the molten metal can be set to a state suitable for reaction with oxygen. According to the die-casting die of the second aspect, in addition to the effect of the die-casting die of the first aspect, the gate can be formed along the mating surface.

According to the die-casting die described in claims 3 and 4, in addition to the effect of the die-casting die described in claim 2, it is only necessary to form a concave surface on one of the end surface and the mating surface of the rod. Since a minimum flow path can be formed between them, it can be easily implemented even with an existing mold or load.

Furthermore, according to the die-casting die according to claim 4, since it is not necessary to form a concave surface defining the minimum flow path of the gate in the die, the size of the minimum flow path portion according to the implementation conditions When changing the mold, the mold does not need to be changed, and it is sufficient to change the mouth which is smaller than that.

Claims

The scope of the claims

1. In a die-casting mold for producing a product by injecting molten metal from the gate into the cavity while replacing the air in the cavity with an active gas,

A cylinder through which the gate passes,

A rod movably housed in the cylinder to adjust a flow passage area of the gate,

A minimum flow path defining portion is provided on the end face and the bottom face so that a minimum flow path of the gate is formed between the end face and the bottom face when the end face of the mouth and the bottom face of the cylinder abut. Provided

A die casting die characterized by the following.

2. The die casting mold includes a first mold and a second mold,

A side surface of the cylinder is formed on one of the first mold and the second mold, and a bottom surface of the cylinder is a mating surface on the other of the first mold and the second mold. The die casting die according to claim 1.

3. The die casting die according to claim 2, wherein the minimum flow path defining portion comprises an end surface of the mouth and a concave surface formed on the mating surface.

4. The die casting die according to claim 2, wherein the minimum flow path defining portion comprises a concave surface formed on an end surface of the rod and the mating surface.