JP4076220B2 - Die casting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a die casting apparatus capable of using an elongated core, a core replacement method, and a die cast molding method.
[0002]
[Prior art]
In general, die casting (mold casting) is a method of casting a molten metal (for example, molten aluminum) into a mold made of sand or the like to make a product, which has high dimensional accuracy and can reduce processing in a later process. The manufacturing method is suitable for mass production. Further, this die cast has a feature that the surface of the product is smooth and excellent, and thus surface treatment such as plating and painting is easy.
This die-casting process consists of three elements: aluminum, which is a raw material, a die-casting machine, and a mold. By pouring molten aluminum (molten metal) into the mold at high pressure, a product can be quickly produced from the raw material. I can get it. This die-casting machine has two types of molds, a fixed mold and a movable mold, and a product can be taken out by opening the movable mold.
The following documents can be cited as techniques relating to the manufacture of die-cast products using such movable molds.
[Patent Document 1]
Patent No. 2950496 [0003]
[Problems to be solved by the invention]
By the way, conventionally, in die-casting, it has been difficult to form a long and narrow hole (the depth is about 10 times or more the width of the cross section) with only the core.
The reason is as follows: (1) A large stress is generated in the core due to the deformation caused by the inflow pressure of the molten metal during casting and the tensile force during the core drawing, and the core is likely to break due to fatigue of the core. Therefore, the mold must be frequently removed from the casting machine for repair, and stable production cannot be performed. (2) If the passage of the cooling fluid (cooling water) is constricted in order to cool the entire length of the core, in the case of a thin core (width of about 10 mm or less), the reduction ratio of the section modulus is large and the stress increases. Besides leading to breakage, the core cost also increases.
For this reason, in order to form a hole as described above, it is usual to use machining after casting, but at the same time, it takes time to process, and at the same time, a dense structure (chill layer) of the cast surface is formed by processing. There was a problem that the porous tissue was exposed after excision.
Further, since the core is configured as a part of the mold, if the core is broken, the mold must be removed and replaced. In some cases, it takes several hours.
[0004]
Therefore, an object of the present invention is to cool the core by cooling means attached to a part of the mold by making use of the axial movement of the core during the casting process without making a hole in the core. An object of the present invention is to provide a die-casting apparatus that is capable of preventing the core strength from being lowered.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, in a die casting apparatus for obtaining a product by die casting, a pair of molds that can be opened and closed in one direction and that forms an outer shell of a casting, and an elongated hole in the mold are provided. when performing injection molding of a product, an elongate tang length relative to the width of the cross-section defining an inner shape is more than 10 times the product, and the holding member for holding the core detachably, the holding member Drive means for driving the mold in a direction perpendicular to the opening and closing direction of the mold, and as a result, driving the core held by the holding member in and out of the mold, and the core by the drive means outside the mold Cooling means fixed at a position where the core can be cooled at the time of taking out, and the cooling means comprises a cooling air nozzle, and the position is adjusted in accordance with the operation of taking out the core by the driving means. Fixed for cooling By blowing air from Anozuru, and performs cooling over the entire length of the elongate core.
According to a second aspect of the present invention, in the first aspect of the present invention, the cooling unit further includes a release agent blowing nozzle, and the position is fixed in accordance with the operation of taking out the core by the driving unit. Cooling is performed over the entire length of the elongated core by blowing air from the cooling air nozzle and blowing the release agent from the release agent blowing nozzle whose position is fixed .
The invention according to claim 3 is the invention according to claim 2, wherein a plurality of pairs of the cooling air nozzle and the release agent spray nozzle are provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7.
FIG. 1 is a view showing a place where a die-cast product is created by the die-cast apparatus 10 according to the present embodiment (place where the movable side is closed). Here, an elongated hole is formed inside the aluminum die-cast product using the elongated core 20.
FIG. 2 shows the core 20 attached to the die cast apparatus 10. In this embodiment, the core 20 is fixed with bolts 24 via a core pin holder 22. Therefore, even if the core 20 is damaged, the other core 20 can be easily replaced by removing the bolt 24. Therefore, if a plurality of cores 20 are prepared in advance, even if the core 20 is damaged, it can be replaced with a new core 20 in a short time.
[0009]
As shown in FIG. 2, the core 20 is engaged with a core pin holder 22, and the core pin holder 22 is held and fixed to a slide 28 by a coupling 26. The slide 28 is guided by a slide guide 30 and is slidable by a hydraulic cylinder 32 in the direction of the arrow in the figure.
That is, the core 20 is detachably attached to the driving slide 28 via the core pin holder 22 and the driving slide 28 via the coupling 26 by the pulling cylinder. By doing so, the core 20 can be easily replaced, and damage can be easily dealt with. In this example, the core 20 can be replaced in about 5 minutes.
[0010]
FIG. 3 is a view showing a state where a die-cast product is manufactured using the thin core 20. In this figure, the movable side 50 contacts the fixed side 40 of the mold, and the core 20 is disposed in the cavity 60 formed by both of them. In this state, molten aluminum (molten metal, 680 ° C. to 7000 ° C.) is poured into the cavity 60 at a high pressure to manufacture a die-cast product.
FIG. 4 is a plan view of the fixed side 40 of the mold, and FIG. 5 is a plan view of the movable side 50.
[0011]
Next, an operation procedure of the die cast apparatus 10 will be described.
In the state shown in FIG. 3, that is, with the mold closed, the molten metal is poured into the cavity 60 at a high pressure to perform injection molding. Then, after a certain solidification time, in this example, 30 seconds, the core 20 is pulled out by the hydraulic cylinder 32. At this time, an elongated hole corresponding to the shape of the core 20 is formed in the die-cast product.
Thereafter, the mold is opened by moving the movable mold 50. The direction in which the mold is opened is a direction orthogonal to the drawing direction of the core 20. When the mold opens, the product is removed from the mold. In this example, the product is removed by dropping the product using an extrusion pin.
[0012]
On the other hand, since the core 20 pulled out from the mold is located in the high-temperature molten metal, the core 20 is considerably hot. Therefore, it is necessary to cool the core 20 in order to maintain the durability of the core 20.
In this example, when the core 20 is pulled out (that is, the movement of the core 20 in the axial direction), cooling is performed by the pin cooling air nozzle 70 and the release agent blowing nozzle 72 provided on the slide guide 30. The air nozzle 70 for pin cooling blows off the water | moisture content of the core 20 by blowing air, and cools with air. Further, the release agent spray nozzle 72 sprays a release agent on the surface of the core 20 for smoothly separating (pulling) the product from the core 20. At the same time, it also serves to cool the core 20.
As shown in FIG. 6, the pin cooling air nozzle 70 and the release agent blowing nozzle 72 may be provided in two pairs in the vertical direction, for example, in three pairs or four pairs.
As described above, since the cooling operation is performed by the pin cooling air nozzle 70 and the release agent blowing nozzle 72 using the drawing operation of the core 20, a hole is provided in the core 20 to perform water cooling. There is no need to do it. Further, since the drawing operation of the core 20 is used, the pin cooling air nozzle 70 and the release agent blowing nozzle 72 itself do not need to be moved at a fixed position.
[0013]
After cooling the core 20, the core 20 is again moved inside the mold by the hydraulic cylinder 32. Thereafter, the movable side 50 is closed, and the molten metal is poured into the cavity 60 at a high pressure to perform injection molding. One cycle of this work is performed in about 40 seconds.
The core 20 used in this example has a length of 300 mm or more and a diameter of 6 to 8 mm. The draft is 6 to 8 minutes.
FIG. 7 shows a product manufactured by the die casting apparatus according to the present embodiment.
[0015]
【The invention's effect】
In the inventions according to claims 1 to 3, the core is moved in the axial direction during the casting process so as to be cooled by a cooling means attached to a part of the mold. It is possible to efficiently perform the cooling without performing a troublesome work.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a die casting apparatus according to an embodiment.
FIG. 2 is a view for explaining how to attach and detach a core.
FIG. 3 is a view showing a state where injection molding is performed by the die casting apparatus according to this embodiment.
FIG. 4 is a plan view of a fixed side of the mold.
FIG. 5 is a plan view of a movable side of a mold.
FIG. 6 is a view showing a state where cooling is performed by a pin cooling air nozzle and a release agent blowing nozzle when the core is pulled out.
FIG. 7 is a view showing a product manufactured by the die casting apparatus according to the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Die-cast apparatus 20 Core 22 Core pin holder 24 Bolt 26 Coupling 28 Slide 30 Slide guide 32 Hydraulic cylinder 40 Fixed side 50 Moving side 60 Cavity 70 Pin cooling air nozzle 72 Release agent spray nozzle

Claims (3)

In die casting equipment that obtains products by die casting,
A pair of molds that can be opened and closed in one direction and that forms the outer shell of the casting;
When performing injection molding of a product having an elongated hole in the mold, an elongated core having a length of 10 times or more with respect to the width of the cross section defining the internal shape of the product,
A holding member for detachably holding the core;
Driving means for driving the holding member in a direction orthogonal to the opening and closing direction of the mold, and as a result, driving means for allowing the core held by the holding member to be taken in and out of the mold; and
A cooling means fixed at a position where the core can be cooled when the core is taken out of the mold by the driving means, and
The cooling means comprises a cooling air nozzle;
A die casting apparatus characterized in that cooling is performed over the entire length of the elongated core by blowing air from the cooling air nozzle whose position is fixed in accordance with the operation of taking out the core by the driving means . The cooling means further comprises a release agent spray nozzle,
In accordance with the operation of taking out the core by the driving means, by blowing air from the cooling air nozzle whose position is fixed, and by blowing the release agent from the release agent blowing nozzle whose position is fixed, 2. The die casting apparatus according to claim 1, wherein cooling is performed over the entire length of the elongated core . The die-cast apparatus according to claim 2 , wherein a plurality of pairs of the cooling air nozzle and the release agent spray nozzle are provided.

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