JPS5890365A - Die casting method for aluminum alloy - Google Patents

Abstract

PURPOSE:To obtain good products free from cavities by forming hollow grooves and fine grooves connecting the hollow grooves and die surfaces to segmental die pieces, and packing molten metal into the cavities under specific conditions. CONSTITUTION:The cavities in dies are maintained under low pressure through the air releasing passages, hollow grooves 21, 22 and fine grooves 23, 24 in segmental die pieces 3, 4. When molten metal is charged into the shaft hole of a sleeve 18, plunger rods 19, 20 are advanced integrally at 0.2-0.6m/sec speed to charge the molten metal of 657-760 deg.C into the cavities; at the same time, the molten metal is pushed and packed into the cavities under 850-1,350kg/cm<2> pressure. Upon lapse of 0.01-3sec since the time when the pressing force attains the prescribed pressure after ending of the packing, only the rod 20 is advanced to press the molten metal >=2sec under 1,000-1,500kg/cm<2> pressure. Thus, the density in the internal parts of the product is increased and the good products having no cavities are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold casting method for products made of aluminum alloy, and particularly for products having a plurality of structures or holes formed axially symmetrically around a central axis, such as an axial plunger. type pump or compressor casing,
Alternatively, this method is suitable for die-casting a fan with a ring, etc.

Die-casting using aluminum alloys produces more gas and is more likely to produce cracks than die-casting using pig iron, and because the cooling rate of the injected aluminum alloy is fast, the molten metal is difficult to mold into a mold with the mold surface of the desired product. It is easy to cause defects in not being able to reach every corner of the mold cavity.

The present invention provides a die casting method in which a desired product is cast into a mold, gas is vented, and hot water can be poured into every corner of the cavity forming the mold surface of the desired product. The cavity is exposed to the atmosphere or a negative pressure source of −0.4 Kt'cJ or more through narrow grooves cut at appropriate locations on the outer periphery of the cavity of the mold in which the mold surface of the desired I-product has been formed. While the cavity is opened to the atmosphere or the pressure is reduced, the molten alloy at a temperature of 680 to 760° C. is injected into the cavity through a gate formed in the mold, and a plunger rod is used to inject the molten alloy into the cavity.
m/see speed and 850-1550 Kg/ci
Press the RF-recorded hot water at a pressure of i to fill the cavity, and when the pressure in the cavity is reduced, continue to communicate with the negative pressure source in the cavity, and after the filling is completed. The present invention relates to a mold casting method for an aluminum alloy in which, when 0.01 to 3 seconds have elapsed, a pressing force of 1000 to 1500 Kg4J is applied to the molten alloy for at least 2 seconds by the plunger rod.

The drawings show an example of an apparatus for implementing the present invention for casting the casing of an axial plunger type congreza, and FIG. 1 is a cross-sectional view of the main part of the casting apparatus, and FIG. 2 is a partial mold piece thereof. Fig. 3 shows a front view of the casting obtained by the apparatus of Fig. 1;

The mold for molding the casing (divided into two at the center of the axial length) of the above-mentioned axial plunger type compressor has a mold surface 1 on the front surface in the axial direction and a p-type surface 2 on the rear surface in the axial direction. split mold pieces 3 to be respectively formed and arranged opposite to each other in the axial direction of the casing;
4 and mold surfaces 5 and 6 for molding half of the circumferential surface of the casing.
It consists of four divided mold pieces 7.8 each having a shape formed therein, and the mold surfaces 1, 2, and 5.6 form a cavity having the same shape as the outer shape of the product. The divided mold pieces 3 are fixed to a fixed die plate 10 fixed to the main body 9 of the casting device, and the divided mold pieces 4 are fixed to a movable die plate 11 that is movable with respect to the main body 9 of the casting device, The split mold pieces 7.8 are tightened by the clamping frame 12 together with the split mold pieces 4 fixed to the movable die plate 11 side.The core 15, which is to form the cylinder hole of the compressor casing, is a split mold piece. A core 14 which is planted in the mold piece 4 and forms the cooling holes of the compressor casing is integrally formed with the split mold piece 6.The split mold piece 5 has its mold surface 1. Bush 1 forming gate 15 approximately in the center of
6 is fitted, and a pouring port push 17 is fitted to the fixed die plate so as to communicate with the gate 15. A casting sleeve 18 for introducing molten aluminum alloy and injecting it into the cavity of the mold is fitted into the pouring port push 17, and the sleeve 18 includes:
A plunger rod with a double structure consisting of a hollow cylindrical plunger rod 19 and a plunger rod 20 fitted into an axial hole of the plunger rod 19 so as to be slidable in the axial direction is inserted so as to be slidable in the axial direction, The casting sleeve 18
The divided mold pieces 5 and 4 are slid to fill the cavity of the mold with molten aluminum alloy injected into the shaft hole from an injection port (not shown) formed in the mold.
The split mold piece 3 is on the mating surface with the split mold pieces 7 and 8.
．． Concave grooves 21 and 22 having a substantially semicircular cross section are provided along the outer periphery of the mold surfaces 1 and 2 carved in the mold surfaces 1 and 2 at a slight distance apart, and these concave grooves 21 and 22 are divided as described above. Are the markings engraved at appropriate intervals on the mating surfaces of mold pieces 3 and 4? It is connected to the mold surface 1.2 by the l4J3 groove 25.24, and the groove 21.
22 are each communicated by a narrow groove 2-5.24 with a cavity surrounded by the mold surfaces 1, 2, 4.5 in the υ mold. As shown in FIG. 2, three bottomed holes 25 are bored from the side of the split mold piece 3 to communicate with each other, and the openings of the bottomed holes 25 are closed with plugs 26. At the same time, an exhaust hole 27 is bored from the other side wall so as to communicate with the bottomed hole 25, and the bottomed hole 25 and the exhaust hole 27 are connected to a low pressure source (not shown) such as a vacuum pump. Configure the exhaust passage. On the other hand, the split mold piece 3 is provided with six holes 28 which open into the concave groove 21 from the fixed die plate 10 side opposite to the bottomed hole 25 or the exhaust hole 27. Six product ejection pins 60 erected on the engaged annular extrusion member 29 are inserted into the holes 28 respectively, and the grooves 21 are inserted through the minute gaps between the product ejection pins 60 and the holes 28. Exclude the air inside through the vent hole 25 and the exhaust hole 27,
A cavity within the mold is communicated with a source of negative pressure. Similarly to the mold piece 2, the split mold piece 4 is also provided with a bottomed hole 61, the opening of which is closed with a plug 62, and the bottomed hole 6 is closed.
1 is connected to a low pressure source (not shown) such as a vacuum pump through an exhaust hole 66 bored in the movable die plate 11 to form an exhaust passage, and a hole 35 through which the product ejection pin 54 is inserted.
is bored so as to cross the bottomed hole 31 and open into the recessed hole 22, so that the minute gap between the bottle 54 and the hole 35 communicates with the recessed groove 22 and the bottomed hole 51. The code 56 in the map is the core that forms the center hole of the product, 57.37
58 is a cooling water passage, 58 is an extrusion bottle, and 59 is a spring.

In order to carry out the method of the present invention using the casting apparatus described above, the split mold piece 4 is fixed to the movable gouly plate 11, and the split mold piece 7 has a mold surface 5.6 that is to form the peripheral surface of the product.
.
and connect them with each other with the required pressure.

These split mold pieces 5, 4, 7.8 are preheated to 150-650r. If the temperature of the mold is below 150°C, the cooling rate of the molten aluminum alloy during casting will be too rapid and the molten metal will not fully fill the mold cavity, causing defects such as molten metal spots and molten metal wrinkles, and may cause problems such as preheating. When the temperature exceeds 558℃, mold surface 1
"l 2 t 5,6 Defects due to seizure such as adhesion of K7# minium alloy occur. The preferable preheating temperature is 180 to 600°C. This preheating of the metal jar is performed while casting continues. can utilize the residual heat from the previous casting.

Next, connect the exhaust hole 27.55 to a low pressure source such as the suction port of a vacuum pump, and connect the bottomed hole 25.25 and the bottomed hole '31.51.
The cavity of the mold is heated by 0.1Ks4m or more, preferably -0.4Ki, through the exhaust passage in the split mold piece 5.4, the recesses 21, 22, and the narrow grooves 26°24.
Pressure is applied to the low pressure of a, and this state is maintained.

The plunger rod 19,20 is retracted within the sleeve 18 to a position where the inlet is opened;
When injected into the molten aluminum alloy through the injection port, the plunger rods 19 and 20 are integrated into 0,
The sleeve 180 is moved forward at a speed of 2 to 0.6 m/see, and the gate 15, which opens approximately at the center of the mold surface 1 of the z-divided mold piece 2 communicating with the sleeve 180, is inserted into the cavity of the υ mold.
While injecting the molten metal at ~760°C, the plunger rod 19.20 pumps the molten metal at a temperature of 850~1350 Kyc.
Press R4 with equal pressure to fill the inside of the chamber.

The higher the degree of vacuum in the cavity, the better; if it is less than -0.4K9/ca, the gas in the cavity may not be fully vented.The relationship between the hot water temperature and the injection speed is It is extremely important that the casting temperature is 680℃.
If injection is performed at a temperature below and at a speed below 0.2 m/sec, the flow of the hot water will be poor and a hot water boundary will occur. If the casting temperature is raised, defects caused by molding will disappear, but if the temperature exceeds 760°C, cracks will occur, and if the injection speed is lowered to 0.
．． If it is more than 6η bales, there will be insufficient time for the gas to escape, or a nest will occur due to insufficient time for the gas to escape. Pressing force 850K
If v'c is less than 4, the pressing force of the molten metal will be insufficient and defects due to pulling will easily occur.If it is more than 1d to 1350, it will prevent flash flash from the mating surfaces of the split mold pieces or the mold will open. This creates a need to strengthen the tightening force. The casting temperature should be 700-75 to make the bathtub more comfortable.
A range of 0°C is preferred, and a range of 720-750°C is optimal. Also, the pressing force is 850 to 1250 Kq/d
It is preferable that

In this first step, the molten aluminum 4 alloy is
5.24 into the Nissin 21, 22, but a product extrusion pin 50.34 is inserted into the hole 28.55 that connects the concave grooves 21, 22 to the exhaust passage. The molten metal does not enter into the holes 28.35 because the gap between them is kept extremely small, for example, about 0.05 to 0.111N.

Next, the plunger rod 19 of the first step. .

When the filling of the molten metal by step 20 is completed and the pressing force reaches a predetermined value, the pressure reaches a predetermined value. ,. Mosagi Sutra. 10.7. While keeping the ranger rod (19) in that position, press Goo 1.
9
--Only the plunger rod 20 is moved forward and applied to the molten metal filled in the cavity and presses the molten metal.

That is, molten aluminum alloy is filled into the cavity of the mold and begins to cool and harden from the outside where it contacts the mold surfaces 1, 2, and 4°5 of the divided mold pieces, but the mold surface on the outer surface of the molten metal starts to harden from the outside. 1, 2, and 4.5 is no longer in a fluid state, and when most of the molten metal inside is in a fluid state, the plunger rod 20 pumps the molten metal into 1 part.
By pressing with a pressure of 000 to 1500 K4/cA, the density inside the product obtained increases, and a good product with almost no defects such as cavities can be obtained. Even if the molten metal in contact with the tip of the plunger rod 20 is in a fluid state, it will not be effective to start suppressing this AZ process. If 0.01 seconds or more elapses, the molten metal at the tip of the plunger rod 20 is completely solidified, so that the pressing effect in the second step is no longer effective. In order to obtain the effect of increasing density by suppressing the second niobium λ to the inside of the product, apply a pressing force in the pressure range of 1000 to 1350 VcIM 0.5 to 1 second after filling by pressing in the first step. Good.

Then, while applying the suppression in the second step described above, the pressure in the cavity of the mold is continued to continue degassing. Preferably, the pressure reduction is started immediately after the split mold pieces are joined and the mold is clamped at a predetermined pressure, and the pressure reduction is continued until immediately before the start of mold opening for product removal, which will be described later.

When the pressing force in the second step reaches a predetermined pressure and the molten metal becomes completely vertical due to the heat dissipation effect of the old man, the pressing force against the fixed die plate (10K) of the movable die plate 11 is released and the movable die plate 11 is slightly lowered. When retracted, the product ejecting pin 50 moves forward due to the elasticity of the spring 59 and lifts the product over the mold surface 1 of the divided gold castle piece 6. Next, tightening frame 1
2, the split mold pieces 7 and 8 are removed, and the product is lifted up from the mold surface 2 of the split mold piece 4 using the product ejecting pin 54 to be taken out.

The invention is based on the creation temperature of 650-670°C, which is commonly used in conventional die casting of aluminum alloys; 1.
Injection speed of 8-2.2 m/sea and 710-10
Compared to the injection pressure of 30 Kv'ca, the inside of the mold cavity is communicated with the atmosphere or -CL 4
The pressure is reduced to more than Kg/c, and the casting temperature is reduced to 680.
In addition to raising the temperature to ~760°C, the injection speed of the molten metal into the mold cavity in the first step was set to a low speed of 0.2 to 0.61 deg., and the pressing force was set to 850 to 1550 Kg'cf! By applying high pressure to the mold, the generated gas is removed from the outer periphery of the cavity through grooves carved in the mold, and the gas is removed from approximately the center of the mold surface of one of the split mold pieces that form the cavity. The molten metal supplied to the cavity through the gate formed in the molten metal is laminarized to eliminate the risk of gas or air being drawn into the molten metal, and the density is increased to fill the cavity. When the fluidity of the surface of the molten metal in the cavity is lost after ~3 seconds,
When reducing the pressure inside the cavity, a pressing force of 1000 to 1500 Kme4 is applied to the molten metal for at least 2 seconds while continuing to reduce the pressure inside the cavity, so that the molten metal has a high density and no cavities. It is a casting method to obtain cast products that almost never exist.

The present invention is extremely suitable for casting with what is called a general aluminum die casting alloy such as Mpa1-12 of the J Engineering S standard.

Gate ratio Rg(cIrLx 10-3)(
7) Selection is important. To calculate this gate ratio,
% formula % However, Ag: gate or cross-sectional area (c4) Sp: volume of desired product (-) 'of volume of niobium flow (cI/I) is generally used.

In the present invention, when the gate ratio Rg is set to 18 to 7 degrees, which is larger than the gate ratio of 5 to 6 that is generally used in die casting, the injection speed of the molten aluminum alloy into the mold cavity is reduced. Despite this, it can be poured in a short period of time, and since it does not cause phenomena such as tin rush during injection, it is extremely effective in preventing the formation of cavities, and the cross-sectional area of the plunger rod used to press the molten metal is The pressure in the second step can be made harder and easier.

Example J engineering S standard A'DO12 aluminum alloy (specific gravity 2.
7), a casing for an axial granger type compressor was cast using the apparatus shown in FIGS. 1 and 2.

A water-soluble release agent containing lead is applied to the mold surface of the mold whose temperature is 120 to 150 °C at the start of casting, and the e4 knee is set to 200 to 280 °C.
After preheating (including residual heat), the exhaust passages passing through the circulation channels 21 and 22 are connected to the intake port of the vacuum pump, and the pressure is reduced to 10 = 7 Kit 14D, and the melt 1i of the alloy is heated.
Weighed 750p and injected it through the injection port of the sleeve 18, and the suppression speed of the plunger rod 18.19 was 0.5 m/sec.
e, pressing force 1250K, Sakizo temperature 740±1
When filling the mold cavity at 0°C, the plunger Rad 20 is 1350 Kg/it after a period of 30 minutes has elapsed.
, was pressed for 5 seconds until the mold opened, and the mold was opened and the product was removed. The decompression time from mold clamping to mold opening was 10 seconds.

The shape of the cast product removed from the mold is shown in FIG. 6, with concave grooves 21 and 22 in the casing 5o of the desired product.
Annular portion 51. ζ2f:m#Ij25,2
4 are connected by thin wire parts 55 and 54 filled in gate 1.
A recess 56 formed by the second stage pressing by the plunger rod 2o was clearly formed in the pressing portion 55 formed by the plunger rod 2o.

Since the average diameter of the gate 15 is 40xx and the weight of the desired product is 7001I, the formula 1%g=AIK
/(81) +g. Calculating the gate ratio according to R
g=12, 54/(700/2.7 + 5072.7
) = 46.45.

Sixty compressor casings were cast using the conventional method described above.

When compared with the pump casing, there is no difference in appearance in terms of the amount of molten metal, but the method of the present invention does not cause seizure or burrs, which was the case with the conventional method. When the molded product was cut out and the machined surface was observed, 25 cavities that were recognized as defects were found in the conventional method, and 4 of them were recognized as rejected as a product, but in the method of the present invention. No cavities recognized as defects were found, and none were recognized as failing.

Furthermore, as a result of carrying out an airtight leakage test on the test piece, it was found that the one made by the method of the present invention showed extremely superior airtightness than the one made by the conventional method, and was found to be suitable for casting a compressor.

And 1 required for casting the casing of the above compressor.
The required cycle time was 5 seconds for the method of the present invention, compared to 60 seconds for the conventional method, and it was found that the method was superior to the conventional method in terms of productivity.

As explained above, the present invention provides an arrangement in which the outer periphery of the cavity formed by the mold surfaces formed on a plurality of split mold pieces is attached to one or more of the split mold pieces along the outer periphery of the mold surface. The inside of the cavity is communicated with a negative pressure source through a groove provided around the mating surface of the mold, and the molten metal is supplied toward the approximate center of the cavity through a gate formed in one of the split mold pieces. However, since the air inside the cavity or the generated gas is to be removed from the outer periphery of the cavity and the molten metal is filled at a relatively slow rate, the desired product is one that is approximately axially symmetrical with respect to the axis. Is it suitable for casting, and as such an axially symmetrical product, a ring is integrally attached to the wing tip as shown in Fig. 4? Examples include valve members shown in vertical direction 1 and FIG. 6. In order to cast such a product, a mold surface that is to form the other surface of the product is placed between two split mold pieces each having a mold surface that is to form the axial end face of the product. Combine the four pollution mold pieces that formed the
One or six of the split mold pieces having mold surfaces to form the opposing end surfaces form the groove and a gas connecting the groove and the mold surface to communicate the cavity with a low pressure source. , by forming a gate having a central axis in the axial direction of the cavity in one of the opposing split mold pieces, and filling the molten metal from the gate in the axial direction of the cavity,
This allows the present invention to be carried out very effectively.

[Brief explanation of drawings]

FIG. 1 shows a cross section #Ii of a casting apparatus suitable for carrying out the present invention.
Figure 2 is a front view of one of the divided mold pieces, Figure 3 is a perspective view of a cast product obtained by implementing the present invention using the apparatus shown in Figures 1 and 2, and Figure 2 is a front view of one of the divided mold pieces. 4 to 6 each show a perspective view of a part of a cast product embodying the present invention. In addition, 5.4 and 7.8 in the figure are split mold pieces 1.2 and 5.6.
2A and 2B show a mold surface 15, a gate 21, a concave groove 25, and a narrow groove 24, respectively. Hall 2 Figure 1!311

Claims (1)

[Scope of Claims] (1) Aluminum die-casting is carried out through a gate formed on one of the split mold pieces into a cavity shaped into a desired product formed by the opposite sides of each of the plurality of split mold pieces. In a mold casting method in which a molten metal of a casting alloy is injected and a pressing force is applied to the molten metal by a plunger rod, the cavity is formed by a narrow groove carved in at least one mating surface of the split mold piece. While the mold is open to the atmosphere, a molten metal of the alloy is injected into one of the divided mold pieces through the gate formed so as to be directed substantially toward the center of the cavity, and the molten metal is injected with a molten metal of 0.2 to 0.6 Pressing speed of object and 85
A first step of filling the cavity at a temperature of 475 to 760° C. by applying a pressing force of 0 to 1350°C with the plunger rod, and when 0.01 to 5 seconds have elapsed after filling the molten metal, the plunger rod 1000 to 1500/c to the molten metal by rod
A method for mold casting an aluminum alloy, comprising a second step of applying a pressing force of (a) for at least 2 seconds. (2) Gate ratio ug (cWLx 111-3) of the gate given by the formula Rg=Av(Sp+5of)
However, Ag: Cross-sectional area of gate (c4) Sp: Volume of desired product (clwaSOf) The volume of overflow (ct) is 18 to 70
A method for mold casting an aluminum alloy according to claim 1, characterized in that: (8) The pressing force and temperature in the first step are 850 to 12501 $i and 700 to 750°C, respectively, and the suppression start time and pressing force in the second step are 0.5 to 1 second and 1000 to 1500 Kv, respectively. A method for mold casting an aluminum alloy according to claim 1 or 2, characterized in that: . (4) A gate formed on one of the split mold pieces is inserted into a cavity shaped into the desired product formed by the mold surfaces formed on each of the plurality of split mold pieces, and the molten metal of shear aluminum die casting alloy is applied to the cavity. In the mold casting method, in which molten metal is injected and cast by applying a pressing force to the molten metal using a plunger rod, a thin groove cut into at least one mating surface of the split mold piece is used to form a mae-machi capitol. is connected to a negative pressure source of -0.1 Kg/:4 or more to reduce the pressure in the cavity, and one of the split mold pieces is directed to substantially the center of the cavity through the gate formed therein. Inject the molten metal of the alloy, and add 0.2 to 0.6rnA-1 to the molten metal.
A pressing speed of - and a pressing force of 850 to 1350 F-g/c4 are applied to the plunger rod to obtain a pressure of 675 to 7.
A first step of filling the cavity at a temperature of 60° C. While continuing to reduce the pressure in the forebrain cavity, when 0.01 to 3 seconds have elapsed after filling the molten metal, the plunger rod is used to fill the molten metal with a temperature of 1,000 to A method for die casting of aluminum alloys, comprising a second step of applying a pressing force of 1500 Kg/lit for at least 2 seconds. (5) For the gate, the formula Rg=Ag/(Sp + 5
Of) the cate ratio Rg(clrLX 1O
-3) However, Ag: cross-sectional area of gate (C4), Bp: volume of desired product (, So, volume of niobium flow (cr!l), 18 to 7
5. The method for mold casting an aluminum alloy according to claim 4, wherein the aluminum alloy is 0. (6) The pressing force and temperature in the first step are 850 to 1250 KV'cA and 7oo to
The temperature was 750°C, and the pressing start time and pressing force in the second step were 0.5 to 1 second and 1000 to 1500.
The method for mold casting an aluminum-ram alloy according to claim 4 or 5, characterized in that: (γ) Division in which a mold surface for forming the axial end face of the desired product is formed on two opposing split mold pieces, and a mold surface for the remaining surface of the desired product is formed between these split mold pieces. A molten metal of an alloy for aluminum die casting is injected through a gate formed in one of the split mold pieces having a mold surface that connects the mold pieces and forms the axial end face, and a pressing force of a plunger rod is applied to the molten metal. In a metal casting method in which a product having a substantially symmetrical shape with respect to an axis is cast by adding A concave groove, which is provided around the mating surface of the split mold piece and communicates with the mold surface through a narrow groove at a suitable place, is opened to the atmosphere and formed in one of the split mold pieces facing the split mold piece. 1. Injecting the molten metal of the alloy into the approximately central portion of the mold surface through a gate that opens in the axial direction of the cavity. 0.2 to 0.0% to the molten metal.
Suppression speed of 6 m/sec and 850-1550 K
a first step of applying a pressing force of g/:J to the plunger rod to fill the cavity at a temperature of 68-0 to 760°C; ¥! When 0.01 to 3 seconds have passed after filling with hot water,
1000 to 1500 to the molten metal by the plunger rod.
The second one applies a pressing force of KG/14 for at least 2 seconds.
An aluminum alloy mold is characterized by casting a product that is approximately symmetrical about an axis.
5or), then Wasarel gate ratio (cm
0 (9) The pressing force and temperature in the first step are 850 to 1250 KiJ and 700, respectively. ~750°C, and the suppression start time and pressing force in the second step are 0.5 to 1 second and 1000 to 1500 degrees, respectively. Mold casting method for aluminum alloy described in 0 A mold surface for forming an axial end face of a desired product is formed in two split mold pieces facing each other, and the remaining part of the desired product is formed between these split mold pieces. Join the split mold pieces that have mold surfaces to form the axial end faces, and pour molten metal of an alloy for aluminum die-casting into the gate formed on one of the split mold pieces that have the mold faces that are to form the axial end faces. In a mold casting method in which a product having a substantially symmetrical shape with respect to an axis is cast by applying a pressing force to the molten metal by a plunger rod, at least one of the opposing split mold pieces is formed in the split mold piece. A concave groove, which is provided along the outer periphery of the mold surface and is connected to the mold surface by a narrow groove at a proper place, is connected to a negative pressure source of -0.1K7A or more. While at least reducing the pressure in the cavity, a gate is opened at approximately the center of the mold surface formed in one of the opposed split mold pieces, and is oriented in the axial direction of the cavity. Inject the molten metal of the alloy from the
~0.6! +I/ec suppression speed and 850-135
A first step of applying a pressing force of 0 Kt'lJ with the plunger rod to fill the cavity at a temperature of 680 to 760°C, and a step of filling the molten metal with Φj while continuing to reduce the pressure in the cavity. When 01 to 5 seconds have elapsed, the plunger rod is heated to 1500 Kv'c4.
and a second step of applying a pressing force of 2 seconds for at least 2 seconds. (111 of the gate, 2Rg = Ag / (sp
+ so, ) gate ratio (cMLx 10
-”) However, Ag: Cross-sectional area of gate (cIt) Sp
: Volume of desired product (cITf) Volume of SOf niobuff 0- (,4) is set to 18 to 70. Law. C (2) The pressing force and temperature in the first step are respectively 850 to 1250 Kglcab J: and 7oo to
The temperature was 750°C, and the suppression start time and pressing force in the second step were 0.5 to 1 second and 1000 to 1500, respectively.
The phosphor casting method for aluminum alloy according to claim 10 or 11, characterized in that Vc-.