JPH0825018A - Pouring method of die casting and oxide removing method - Google Patents

Abstract

PURPOSE:To reduce an intruding quantity of oxide into a product in high pressure casting by providing a fixed shaft having annular clearance in the center part of throat part and a discoid molten metal dispersing plate having annular clearance with an oxide removing plate at the lower part of fixed shaft. CONSTITUTION:When pouring to an injection sleeve 24 is completed, an cap shape housing 62 is lifted a little bit, positioning an oxide removing plate 64 and molten metal surface in the intersecting direction, left side half of the oxide removing plate 64 and part of a molten metal dispersing plate 74 are exposed above molten metal surface. the oxide floated on molten metal surface is caught by both the oxide removing plate 64 and molten metal dispersing plate 74. When the cap shape housing 62 is lifted, half right side)of the oxide removing plate 64 and molten metal dispersing plate 74 are exposed above molten metal surface, oxide is loaded thereon and remaining oxide is caught as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting hot water supply method and an oxide removing apparatus for obtaining a cast product having less oxide mixed therein and excellent in mechanical properties.

[0002]

2. Description of the Related Art FIG. 10 is a front view of a conventional biscuit. An injection molding device such as a die casting machine is equipped with a fixed mold mounted on a fixed plate and a movable mold mounted on a movable plate, and a cavity is formed at a joint portion between these molds that are clamped. Has been formed. In addition, a fixed sleeve, which communicates with the cavity through a gate, is fitted in the sleeve hole of the fixed mold, and the injection sleeve of the injection cylinder supported on the fixed plate side is attached to and detached from this fixed sleeve. Freely joined. With this structure, when the molten metal is supplied to the injection sleeve and joined to the fixed sleeve, the plunger tip provided in the injection cylinder is hydraulically advanced, and the molten metal in the injection cylinder is pushed, the molten metal is It is injected into the cavity through the fixed sleeve and the gate.

Since the molten metal in the cavity is solidified to form a product, the mold is opened to take out the product. At this time, the surplus casting material is separated from the product in the injection sleeve and the gate. Be done. That is, when the molten metal solidifies, a large-diameter, thin-cylindrical molten solidified material, commonly called a biscuit, remains in the mold cavity, and a small diameter that also protrudes from the center of the molten molten metal solidified in the gate. A columnar molten metal solidified substance remains (hereinafter, the entire cast surplus material composed of the molten metal solidified substance in the sleeve and the molten metal solidified substance in the gate is called a biscuit. Further, the molten metal solidified substance in the sleeve is the large-diameter member 82. The solidified material in the gate is referred to as a small diameter member 83). When casting, non-metallic inclusions such as oxides of the molten metal enter the cavity, so that the quality of the product deteriorates. Therefore, in general, the wire mesh indicated by reference numeral 84 in FIG. 10 is loaded in the gate every shot. Sometimes. Then, this wire net is left embedded in the small diameter member. The biscuit 81 is separated from the cast product thus produced.

[0004]

However, when the metal net is loaded into the gate from below as in the prior art, and the aluminum alloy poured into the injection sleeve is pushed up by the plunger tip to fill the mold cavity, The oxides and non-metallic inclusions on the surface of the molten metal prevent part of the mixture inside the product by the metal net 84, but the remaining oxides and non-metallic inclusions are finely crushed by the metal net 84 and filled in the cavity together with the molten metal. It Therefore, good mechanical properties were obtained. However, the conventional biscuit 81 is integrally formed with the large-diameter member 82 and the small-diameter member 83 as described above, and the wire net 8 is formed on the small-diameter member 73 which is solidified in the gate.
Since 4 was left buried, there was a problem that the yield of the material was poor because it could not be recovered and reused as it was.

In view of the above conventional problems, the present invention has an object to provide a hot water supply method and an oxide removing apparatus in which the amount of oxides mixed into the product during high pressure casting of aluminum alloys or magnesium alloys is small. It is a thing.

[0006]

In order to solve such a problem, in the first invention of the present invention, oxide removal having an annular gap between the vertical injection sleeves at the lower end of the upper door-shaped container is removed. Plate and the oxide removing plate, a molten metal dispersion plate having a diameter smaller than that of the oxide removing plate is fixed, and an oxide removing device that can move up and down coaxially with the injection sleeve is used. Hot water is supplied from above the upper door-shaped container in a state of being positioned at an appropriate height, and is made to flow down through the throat part in the middle, and the upper door-shaped container is raised in accordance with the molten metal surface rising speed, and when hot water supply is completed. After arranging the oxide removal plate and the molten metal dispersion plate so as to intersect with the molten metal surface, capture the oxide in a portion exposed from the molten metal surface and take out integrally with the oxide removal plate and the molten metal dispersion plate. I chose Further, according to a second aspect of the present invention, there is provided an oxide removing device for supplying hot water from a ladle to an injection sleeve through an upper door-shaped container to remove oxides in the molten metal. A throat portion having a small diameter portion is formed into a bell mouth portion in a divergent shape, a donut-shaped oxide removing plate is provided at the lowermost end of the bell mouth portion, and a fixing having an annular gap in the central portion of the throat portion. The shaft was arranged coaxially, and a molten metal dispersion plate having an annular gap between the oxide removal plates was provided below the fixed shaft.

[0007]

[Function] When the molten metal is supplied from the ladle through the upper door-shaped container inserted in the injection sleeve, the molten metal is once stored in the storage part and flows down through the gap in the throat part, and is split left and right on the molten metal dispersion plate. It flows out into the injection sleeve from the gap of the dispersion plate and is stored in the injection sleeve. Therefore, the molten metal supplied into the injection sleeve is prevented from scattering with turbulent flow, and the molten metal is less likely to be newly oxidized in the injection sleeve. When the oxide removal plate is positioned so as to intersect the molten metal surface when the hot water supply is completed, the upper door-shaped container is further pulled up, and the oxide is captured on the oxide removal plate and the molten metal dispersion plate. Therefore, a cast product can be obtained in which oxide removal is easy and the amount of oxide inclusion is small.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of a method for producing a cast product with a small amount of oxides according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic view showing a relative state of an oxide removing device and an injection sleeve according to an embodiment of the present invention, and FIGS. 2 to 5 are oxidations mixed in the injection sleeve according to the embodiment of the present invention during pouring. FIG. 6 is a diagram illustrating a method of removing an object, FIG. 6 is a vertical cross-sectional view of an upper door-shaped container, and FIG.
FIG. 8 is a front view of a vertical casting die casting machine, and FIG. 9 is a vertical cross-sectional view of a vertical injection device.

In FIGS. 8 and 9, a pit 1 having a rectangular shape in plan view is provided below the floor surface.
A pair of machine bases 2 each having a frame shape made of steel plate or shaped steel extend on the floor surface at both ends of the machine base, and one end of each of the machine bases 2 has a substantially square shape. The fixed platen 3 thus formed is placed on the leg portion 3a thereof.
Is fixed by bolting.

An end platen 4 is erected and fixed to the other end of the machine base 2 so as to be movable and adjustable. The fixed platen 3 and the end platen 4 are four corners with four tie rods 5. After being connected and adjusted for movement, they are fixed with a nut 6. Numeral 7 is a movable platen which is fitted into the tie rods 5 at the four corner holes so as to be able to move forward and backward with respect to the fixed platen 3. The movable platen 7 is provided between the piston rod 9 of the mold clamping cylinder 8 and the toggle mechanism 10. The piston plate 9 is moved forward and backward by hydraulic pressure to move forward and backward with respect to the fixed platen 3.

A fixed mold 11 having cavities 11a, 12a and a biscuit portion 15 and a movable mold 12 are mounted on the fixed platen 3 and the movable platen 7, respectively, and driven by a mold clamping cylinder 8 to move the movable platen. The mold is clamped as shown in FIG. 1 by advancing the mold 7 from the mold open state.

Next, a vertical casting type injection device 13 arranged in the pit 1 will be described. Reference numeral 20 denotes an injection cylinder pivotally supported by a seat 18 fixedly provided on the bottom surface of the pit 1 via a pin 19, and the injection cylinder 20, the docking frame 22, and the injection sleeve 24 are sequentially arranged from the lower side. It has a staircase configuration. A piston 26 is installed in the injection cylinder 20.
A rod 28 extending upward is connected to the.
The docking frame 22 is provided with a cylinder hole 30 extending in the vertical direction, a docking ram 32 is inserted into the cylinder hole 30, and the lower end of the docking ram 32 is a flange 34 formed on the upper surface of the injection cylinder 20.
It is stuck to.

The injection sleeve 24 is connected to the upper side of the docking frame 22 via a connecting member 36, and the upper end thereof can be inserted into the lower end of the biscuit portion 15. A plunger tip 38 is slidably installed in the injection sleeve 24, and a lower end of a plunger 40 holding the plunger tip 38 is a coupling 42.
It is connected to the upper end of the rod 28 via. A tilting cylinder 44 is pivotally supported by a side wall of the pit 1 via a seat 46 and a pin 48, and a rod 52 connected to a piston 50 of the tilting cylinder 44.
Has its tip pivotally attached to the side surface of the flange 34 of the injection cylinder 20 via a joint 54 and a pin 56.

Reference numeral 60 is an oxide removing device, which is composed of an upper door-shaped container 62 and an oxide removing plate 64, and the upper door-shaped container 62 is composed of a storage portion 65, a throat portion 66, and a bell mouth portion 67. Has been done.

The upper door-shaped container 62 is rectified at the throat portion 66 and flows down toward the bottom of the injection sleeve 24 without generating a turbulent flow such as a twist in the molten metal 69 supplied from the ladle 68. To do.

The upper portion of the upper door-shaped container 62 has an enlarged diameter portion as shown in FIG. 1, and the molten metal 6 is supplied from a ladle 68.
A storage unit 65 for temporarily storing 9 is provided.

Further, when the molten metal 69 stored in the storage portion 65 flows down through the throat portion 66 having a small diameter portion in the lower portion of the storage portion 65 in the middle portion of the upper door-shaped container 62, it is rectified and twisted. It has a structure that does not cause turbulence.

Further, the throat portion 6 of the upper door-shaped container 62
The lower part of 6 has a bell mouth part 67 that is divergent toward the bottom.
And a donut-shaped oxide removing plate 64 is fixed to the lowermost end of the bell mouth portion 67. As shown in FIG. 6, in the axial direction of the throat portion 66, a fixed shaft 75 having a diameter smaller than the inner diameter of the throat portion 66 is fixed by a frame 76 radially extending in all directions. Throat 6 where molten metal 69 flows down between 75
Six gaps 77 are provided.

As shown in FIG. 7, a disk-shaped molten metal dispersion plate 74 is fixed to the lower end of the fixed shaft 75 in a direction orthogonal to the fixed shaft 75, and a donut-shaped oxide removing plate 64 is provided.
A gap 78 of the molten metal dispersion plate is provided between the inner diameter portion of the molten metal and the outer diameter portion of the molten metal dispersion plate 74.

It is desirable that the molten metal dispersion plate 74 is disposed at a position slightly below the oxide removal plate 64.
This is to facilitate the removal of the oxide 72 trapped on the molten metal dispersion plate 74 by blowing the compressed air 70.

The oxide removing plate 64 is a flat plate having a diameter such that the projected cross section A1 is 80 to 95%, preferably 75 to 90% of the cross sectional area A2 of the injection sleeve 24.

When the ratio A1 / A2 is 80% or less, the gap 73 between the oxide removing plate 64 and the injection sleeve 24 becomes large, so that it may be mixed in the molten metal 69 when hot water is supplied or a new
It is difficult to remove the oxide 72 that is generated next.

When A1 / A2 is 95% or more, the molten metal 69 supplied from the ladle 68 through the upper door-shaped container 62 into the injection sleeve 24 has a gap 73 as it is stored in the injection sleeve 24. When flowing upward from below, flow resistance increases, the depth of the molten metal 69 does not easily increase, and the amount of hot water supplied tends to decrease.

Further, as a result of suppressing the flow of the molten metal 69 from the lower side to the upper side in the gap 73, the amount of the oxide 72 entrained in the molten metal 69 is reduced and the removal efficiency of the oxide 72 is lowered.

As the material of the oxide removing device 60, for example, a metal, a nonmetal, or a composite material thereof which does not melt against the molten aluminum alloy or magnesium alloy is used. Reference numeral 57 is a gate portion, 58 is a fixed sleeve, 59 is a mold sleeve, and 73 is an annular gap provided between the oxide removing plate 64 and the injection sleeve 24.

The operation of the vertical injection device configured as described above will be described.

First, the movable platen 7 is advanced by the mold clamping cylinder 8 to clamp the molds 11 and 12, and then the rod 52 of the tilt cylinder 44 is advanced to tilt to the chain line position as shown in FIG. A lubricant is spray-supplied to the injection sleeve 24 from a lubricant spray device (not shown). Next, while holding the oxide removing device 60 with a holding device such as a robot (not shown), it is lowered in the axial direction of the injection sleeve 24 so that a uniform annular gap is provided between the oxide removing plate 64 and the injection sleeve 24. And the height of the oxide removing plate 64 in the injection sleeve 24 is set to, for example, 2/5 of the height H1 of the injection sleeve 24 (FIG. 2).

Next, for example, an aluminum alloy molten metal 69 is pumped from a molten metal holding furnace (not shown) by a ladle 68, and while tilting on the injection sleeve 24, the molten metal 69 is once gently supplied onto the upper door-shaped container 62. Then, the molten metal 69 once stored in the storage portion 65 is not covered with the gap 77 in the throat portion.
Then, it flows down as it is rectified, and naturally spreads in a divergent shape at the bell mouth portion 67, and then flows out into the injection sleeve 24 through the gap 78 of the molten metal dispersion plate.

At this time, the vortex flow of the molten metal 69 is made as slow as possible to prevent the entrainment of air and to reduce the entrainment of the oxide 72 in the molten metal 69.

When the molten metal 69 is continuously supplied into the injection sleeve 24 through the upper door-shaped container 62, the molten metal 69 previously supplied into the injection sleeve 24 passes through the gap 73 and is gradually oxidized when the molten metal surface gradually increases. Object 72 is also accompanied.

While hot water is being supplied to the injection sleeve 24, the upper door-shaped container 62 is raised while being careful that the surface of the molten metal 69 is constantly positioned above the oxide removing plate 64 (FIG. 3).

When the hot water supply to the injection sleeve 24 is completed, the upper door-shaped container 62 is slightly pulled up, the oxide removing plate 64 and the molten metal 69 are positioned in the intersecting direction, and the left half of the oxide removing plate 64 is located. When a part of the molten metal dispersion plate 74 is exposed from the molten metal surface, the oxide 7 floating on the molten metal surface of the molten metal 69
2 is captured by the oxide removal plate 64 and the molten metal dispersion plate 74.

At this time, the right half of the oxide removing plate 64 and most of the molten metal dispersion plate 74 are still immersed in the molten metal 69, and the oxide 72 is left on the oxide removing plate 64 in the right half. Remains floating on the surface of the molten metal and is not captured (Fig. 4).

When the upper door-shaped container 62 is pulled up in the state described above, the oxide removing plate 64 and the molten metal dispersion plate 74 on the right half are also exposed on the molten metal surface, the oxide 72 is placed, and the remaining oxide 7
2 is also captured.

Thus, after the oxide 72 is trapped on the upper surfaces of the oxide removing plate 64 and the molten metal dispersion plate 74 and pulled up integrally from the injection sleeve 24, it is moved to an appropriate position as it is.

The oxide 72 captured on the oxide removing plate 64 or the molten metal dispersion plate 74 is removed by moving the oxide removing device 60 to an appropriate position and then blowing compressed air 70 or the like. (Fig. 5). The case where the compressed air 70 is used to remove the oxide 72 by spraying has been described, but nitrogen gas or the like may be sprayed.

Further, the case where the oxide 72 is removed and the compressed air 70 is blown has been described.
May be removed by external heating, vibration, suction or grasping.

On the other hand, when the pouring into the injection sleeve 24 is completed, pressure oil is introduced to the piston rod 52 side of the tilt cylinder 44 to erect the injection device 13. Next, when pressure oil is introduced into the cylinder hole 30, the docking frame 22 starts to rise at a predetermined speed to bring the injection sleeve 24 into contact with the fixed sleeve 58. Further, pressure oil is introduced into the head side of the piston 26 to raise the plunger tip 38 and raise the molten metal 69 into the injection sleeve 24. Finally, pressure oil is introduced into the injection cylinder 20 to further raise the plunger tip 38, and the molten metal 69 is introduced into the cavities 11a and 12a.
Is filled. Molten metal 69 into the cavities 11a and 12a
After the solidification is completed, the plunger tip 38 and the docking frame 22 are lowered and tilted to the chain line position shown in FIG. 9, and the molds 11 and 12 are opened to open the cavity 1
The castings in 1a and 12a are taken out and one cycle is completed. The product and the biscuit 81 are cut and separated in a later process.

[0040]

As is apparent from the above description, according to the first aspect of the present invention, the oxide removing plate having the annular gap between the vertical injection sleeves is provided at the lower end of the upper door-shaped container. An oxide removing device that is located in the center of the oxide removing plate and has a diameter smaller than that of the oxide removing plate is fixed to the oxide removing plate and is vertically movable in the axial direction of the injection sleeve. Hot water is supplied from above the upper door-shaped container in a state of being positioned at the height, and is made to flow down through the throat partway along the way, and the upper door-shaped container is raised in accordance with the molten metal level rising speed, and when the hot water supply is completed, the oxidation After the object removal plate and the molten metal dispersion plate are positioned so as to intersect with the molten metal surface, the oxide is trapped in the portion exposed from the molten metal surface so that the oxide removal plate and the molten metal dispersion plate are taken out integrally. . Furthermore, the second
In the invention of (1), there is provided an oxide removing device for supplying hot water from a ladle to an injection sleeve through an upper door-shaped container to remove oxides in the molten metal. The throat portion having a divergent bell mouth portion is formed, a donut-shaped oxide removing plate is provided at the lowermost end of the bell mouth portion, and a fixed shaft having an annular gap in the central portion of the throat portion is coaxial. Since a molten metal dispersion plate having an annular gap between the oxide removal plates is provided in the lower part of the fixed shaft, it is possible to prevent outside air and oxides from being entrained in the molten metal. It is possible to obtain cast products with extremely superior quality compared to the cast products of. Further, since the wire mesh is not buried in the biscuit portion, the surplus casting material (biscuit) can be effectively used, and the yield is improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing a relative state of an oxide removing device and an injection sleeve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a hot water supply unit showing a state before hot water is supplied to the injection sleeve.

FIG. 3 is an explanatory diagram showing a hot water supply state to the injection sleeve.

FIG. 4 is a diagram illustrating a method of removing oxide in an injection sleeve.

FIG. 5 is an explanatory view of processing the oxide removed in the injection sleeve.

FIG. 6 is a vertical cross-sectional view of an upper door-shaped container.

7 is a cross-sectional view as seen from AA of FIG.

FIG. 8 is a front view of a vertical casting die casting machine.

FIG. 9 is a vertical sectional view of a vertical injection device.

FIG. 10 is a front view of a conventional biscuit.

[Explanation of symbols]

 3 Fixed Platen 4 End Platen 5 Tie Rod 10 Toggle Mechanism 11 Fixed Die 12 Movable Dies 11a, 12a Cavity 13 Injection Device 15 Biscuit Part 20 Injection Cylinder 22 Docking Frame 24 Injection Sleeve 32 Docking Ram 38 Plunger Chip 40 Plunger 44 Tilt Cylinder 58 Fixed sleeve 60 Oxide removal device 62 Upper door-shaped container 64 Oxide removal plate 65 Storage part 66 Throat part 67 Bell mouth part 68 Ladle 69 Molten metal 70 Compressed air 72 Oxide 73 Gap 74 Molten metal dispersion plate 75 Fixed shaft 77 Throat Gap between parts 78 Gap between molten metal dispersion plates

Claims (2)

[Claims] 1. An oxide removal plate having an annular gap between vertical injection sleeves at the lower end of an upper door-shaped container, and a molten metal dispersion located at the center of the oxide removal plate and having a smaller diameter than the oxide removal plate. Using an oxide removing device that fixes the plate and can move up and down coaxially with the injection sleeve, hot water is supplied from above the upper door-like container in a state of being positioned at an appropriate height in the injection sleeve,
While letting it flow down through the throat part of the way, raise the upper door-shaped container in accordance with the rising speed of the molten metal, and position the oxide removal plate and the molten metal dispersion plate so as to intersect the molten metal surface when the hot water supply is completed. After that, a method for supplying hot water for die casting is characterized in that oxide is captured in a portion exposed from the surface of the molten metal and the oxide is removed integrally with the oxide removing plate and the molten metal dispersion plate. 2. An oxide removing device for supplying hot water from a ladle to an injection sleeve through an upper door-shaped container to remove oxides in the molten metal, wherein a lower portion of the upper door-shaped container has a small diameter portion. From the throat portion having a divergent bell mouth portion, a donut-shaped oxide removal plate is provided at the lowermost end of the bell mouth portion, and a fixed shaft having an annular gap in the central portion of the throat portion is coaxial. The oxide removing device is characterized in that a molten metal dispersion plate having an annular gap between the oxide removing plates is provided below the fixed shaft.