JPH01289556A - Apparatus for manufacturing casting for heat treatment - Google Patents

Abstract

PURPOSE:To prevent defect in a casting product and to improve strength by setting a filter in a runner from a sleeve to cavity and executing casting with molten metal removing solidified layer or oxide. CONSTITUTION:Recessed parts 4a, 6a are arranged in a fixed die 1 and movable die 2 and the cavity 8 having product shape is formed at facing surfaces of working parts 5, 7. Then, a gate 14 is arranged in the runner 9 from the slave 10 to the cavity 8 and the filter 17 supported to slits 15, 16 is set at the downstream side. The cavity 8 is formed with the movable die 2 and fixed die 1, and the molten metal 13 is poured into the sleeve 10, and by driving a chip 12, the molten metal 13 is supplied into the cavity 8, to execute the casting. As the solidified material and oxide in the molten metal 13 in the cavity 8 is surely filtrated with the filter 17, the development of the defect in the casting product is prevented and the strength thereof is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an apparatus for manufacturing castings for heat treatment by a die casting method using horizontal low-speed filling and high-pressure casting, and in particular, to suppress entrainment of oxides or solidified layers in the product. The present invention relates to a manufacturing device for castings that have high strength, high quality, and can be heat treated.

[Prior Art] The die casting method is a method for manufacturing aluminum alloy cast parts in large quantities and with high precision, and has the advantage of high productivity. However, in this die-casting method, the molten metal is injected under pressure into the mold cavity at high speed, so the gas inside the cavity is not sufficiently exhausted, and the gas gets caught inside the product and causes blistering when heat-treated. There is a drawback.

Therefore, for high-strength castings that require heat treatment, a slow-filling die-casting method was developed to reduce gas entrainment. It is used after being heat treated.

[Problems to be Solved by the Invention] However, when measuring the actual strength of these heat-treated cast products, there is a large variation in strength within the same product. In particular, inclusion of oxides or coagulated layers on the fracture surface of the tensile test specimens was observed in areas with low strength, and these are thought to have an adverse effect on the strength.

In other words, in the slow-filling die-casting method, which is a heat-treatable casting method, the molten metal stays in the sleeve for a long time because the filling speed of the plunger tip is slow, so the molten metal cools in the sleeve and forms a solidified layer. may occur. In addition, generation and entrainment of oxides were observed when the molten metal fell when poured into the sleeve. It is thought that the solidified layer or oxide thus generated is mixed into the cast product and becomes a starting point for fracture.

Due to this solidified layer or the inclusion of oxides, the strength of the cast product increases from the tensile strength of about 37 kg f/- in a healthy case to about 2
In addition to a significant decrease to 5 kgf/-, the coagulation layer or oxide contamination causes blistering during heat treatment.

That is, when a solidified layer is mixed into the molten metal, the viscosity of the solidified layer is high, and the viscosity of the unsolidified molten metal is low, so that the molten metal does not flow in a negative manner when filling the molten metal. For this reason,
Disturbances in filling the molten metal can easily cause gas entrainment.
Then, blistering occurs due to heat treatment using this gas as a starting point.

In addition to the above-mentioned low-speed filling die-casting method, there are other casting methods that can heat-treat castings, such as the P, F, die-casting method or the G, F, die-casting method, but due to the same circumstances in these cases, There are problems with strength reduction or blistering due to heat treatment.

The present invention has been made in view of such problems, and includes:
An object of the present invention is to provide an apparatus for producing a heat-treatable casting that can produce a heat-treatable, high-strength casting by suppressing the entrainment of a solidified layer or oxide.

[Means for Solving the Problems] An apparatus for producing a heat treatment casting according to the present invention includes a casting mold in which a cavity and a runner having a predetermined shape are formed, a sleeve member communicating with the runner, and the sleeve member. a tip inserted into the sleeve member, a molten metal supply means for supplying molten metal into the sleeve member through a molten metal supply port provided in the sleeve member, and a molten metal supply means for moving the tip forward to feed the molten metal in the sleeve through the runner It is characterized by having a driving means for injecting water into the runner, and a filter member provided interposed in the runner.

[Function] In the present invention, first, the molten metal supply means supplies molten metal such as aluminum alloy into the sleeve member, and then the drive means moves the tip forward to move it into the sleeve toward the runner of the casting mold. The molten metal flows through the runner and is injected into the cavity of the casting mold, where it cools and solidifies into the casting mold.

In this case, the molten metal is filtered by a filter provided in the runner, and the coagulated layer or oxides in the molten metal are removed by this filter. Furthermore, in the present invention, since the filter is provided in the runner, the molten metal is filtered immediately before being injected into the cavity, and is not reoxidized after the filtration process. The injected molten metal is clean without solidified layers or oxides, and a sound casting is produced. Therefore, even when this casting is heat treated, defects such as blistering do not occur.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing a manufacturing apparatus according to an embodiment in which the present invention is applied to a horizontal low-speed filling die-casting method. The mold in this manufacturing device is divided into a fixed mold 1 and a movable mold 2, the fixed mold 1 being fixedly installed, and the movable mold 2 being reciprocated in the horizontal direction by an appropriate drive device 3. .

The fixed mold 1 is divided into a support part 4 and an actuating part 5 that is fitted into a recess 4a provided in the support part 4. The support part 4 is fixed to a suitable support device, and the actuating part 5 is fitted into the recess 4a so that there is no step between it and the support part 4 at its edge.

On the other hand, the movable mold 2 is also divided into a support part 6 and an actuating part 7 that is fitted into a recess 6a provided in the support part 6. The support part 6 is fixed to the drive device 3, and the actuating part 7 has a recess 6 at its edge so that there is no step between it and the support part 6.
It is fitted in a.

A recess of a predetermined shape is formed on the surface of the actuating part 5.7, and when the movable mold 2 is advanced by the drive device 3 and brought into contact with the fixed mold 1, the surfaces of the re-actuating parts 5 and 7 are overlapped. A product-shaped cavity 8 is formed in the center of the surface.

A cylindrical sleeve 10 is disposed at the bottom of the fixed mold 1 with its axial direction being horizontal. An end of the sleeve 10 on the side of the abutting surface of the fixed die 1 communicates with the cavity 8 via a runner 9. On the other hand, a cylindrical tip 12 is inserted into the outer end of the sleeve 10, and the tip 12 is reciprocated in the horizontal direction by an appropriate drive device. Further, a hot water supply port 11 is bored in the upper wall of the outer end of the sleeve 10, so that molten metal 13 is supplied into the sleeve 10 from an appropriate molten metal supply source through the hot water supply port 11. It has become.

A weir 14 is disposed on the upstream side of the runner 9 in the molten metal flow direction from the sleeve 10 to the cavity 8.
A slit 15 provided in the actuating part 5.7 is provided in the downstream part.
．． A filter 17 is disposed so as to be supported by the filter 16 . The weir 14 is a molten metal passage that connects the sleeve 10 or the runner 9 and the product cavity 8, and has the required cross-sectional area to allow the molten metal to enter the cavity 8 quietly.

FIG. 2(a) is an enlarged sectional view showing the vicinity of the filter 17, and FIG. 2(b) is a sectional view of the same portion (a).
) is a sectional view seen from a direction perpendicular to the direction seen in FIG. The width of the slit 15 formed in the operating part 5 of the fixed mold 1 is substantially equal to the width of the filter 17, and the thickness thereof is slightly thicker than that of the filter 17.

On the other hand, the upper surface of the slit 16 formed in the actuating part 7 of the movable mold 2 is located above the upper surface of the slit 15, and the lower surface thereof is located below the lower surface of the slit 15.

Further, on both sides, the slit 16 is located further outward than the slit 15. Therefore, as shown in FIG. 2(b),
The area of the insertion opening of the slit 16 is wider than that of the slit 15, and as shown in FIG. The lower surface is inclined at an angle of 1° or more, preferably about 5°, with respect to the horizontal direction.

The filter 17 may be anything that can capture the solidified layer or oxides in the aluminum alloy, for example,
There are types such as woven wire mesh, punched iron plates, or ceramic filters.

Specifically, woven wire mesh type filters include those of plain weave wire mesh, twill wire mesh, and tatami weave wire mesh (J I 5G
3555), :(7) Woven wire mesh has a wire diameter of 0.03 to 1
．． The mesh is made of OO+n annealed iron wire, galvanized iron wire, or stainless steel wire, and has a mesh coarseness of 2 to 400 meshes.

In addition, the wall thickness of the punched iron plate type filter is 0.4
An iron plate or galvanized iron plate of 2.0 to 2.0 II+m is used, which is punched out with an open area ratio of 20 to 75%, usually 30% or 50%.

Furthermore, as a ceramic filter, the wire diameter is 0.2 to 2.
．． A wire made of ceramic material such as alumina or magnesia of 0++v+ is formed into a mesh shape, and the mesh is laminated to form a mesh having a thickness of 2 to 10 mm.

In the method of this embodiment, first, the filter 17 is inserted into the slit 15 provided in the actuating part 5 of the fixed mold 1 while the movable mold 2 is separated from the fixed mold 1, and then the driving device 3 is driven. Then move the movable mold 2 against the fixed mold 1.

As a result, the actuating part 7 of the movable mold 2 is connected to the actuating part 5 of the fixed mold 1.
A cavity 8 having a predetermined product shape is formed. Also, the filter 17 supported within the slit 15
slit 1 has an insertion opening larger than slit 15.
6 is fitted. As described above, this slit 16 is larger than the slit 15, and its upper and lower surfaces and side surfaces are located further outward than the upper and lower surfaces and side surfaces of the slit 15 when viewed from the side. Therefore, the movable mold 2 is brought into contact with the fixed mold 1. When
This slit 16 is smoothly fitted into the filter 17, and the filter 17 is prevented from being damaged by unnecessary stress from the movable mold 2.

In this way, the filter 17 is installed in the middle of the runner 9 through the slits 15 and 16, and the movable mold 2 and the fixed mold 1 are assembled. Next, molten aluminum alloy 13 is poured into the sleeve 10 through the molten metal inlet 11 . in this case,
Oxide is generated by falling molten metal. Also, sleeve 1
0, the molten metal is cooled and a solidified layer is generated on the inner peripheral surface of the sleeve 10.

Next, the tip 12 is moved forward at a low speed to push the molten metal 13 toward the runner 9, and the molten metal 13 is supplied to the cavity 8 via the runner 9. This molten metal 13 is filtered when passing through a filter 17 disposed in the runner 9, and the coagulated layer and oxides in the molten metal are removed. Therefore, the cavity 8 is supplied with a clean molten metal 13 containing few solidified layers and oxides.

The advancing speed of the tip 12 is preferably such that the flow rate when the molten aluminum alloy flows through the runner 9 is 100 CII/sec or less.
Depending on the inner diameter of the tip 12, the forward speed of the tip 12 is between 3 and 2.
If the forward speed of the tip 12 is less than 3 CII/sec, which is preferably 0C11/sec, defects such as hot water not turning or hot spots will occur. - On the other hand, the forward speed of the chip 12 is 20C
If it exceeds 1 l/sec, in order to control the flow rate of the molten metal in the runner 9 to 100 cm/sec or less, the ratio of the flow cross-sectional area F of the runner 9 to the longitudinal cross-sectional area S of the inner space of the sleeve 10 must be adjusted. F/S needs to be 20/100=115 or higher,
The cross-sectional area F of the runner 9 becomes extremely large. As a result, solidification delays and cavities are likely to occur in the runner 9 in which the weir 14 is provided, and the yield is also reduced.

When the molten metal 13 is injected into the cavity 8 at a low speed in this way, the molten metal 13 is cooled and solidified in the cavity 8 by the operating parts 5.7 of the fixed mold 1 and the movable mold 2, and the desired product is cast. . Since the molten metal 13 is filtered by the filter 17 immediately before being injected into the cavity 8, the solidified layer or oxides generated when the molten metal is supplied to the sleeve 20 are removed by the filter 17 and are not supplied into the cavity 8. Further, after the molten metal 13 is filtered by the filter 17, there is very little possibility that it will be re-oxidized. As a result, defects such as blistering do not occur during post-process heat treatment, and a high-strength cast product can be obtained.

After casting is completed, the movable mold 2 is moved backward by the drive device 3, and
The fixed mold 1 and the movable mold 2 are separated and the casting solidified in the cavity 8 is taken out. In this case, the operating part 7 of the movable mold 2
Since the upper and lower surfaces of the slit 16 provided in the slit 16 are inclined so that the insertion port side widens, the solidified portion within the slit 16 is smoothly pulled out from the slit 16 when the movable mold 2 retreats.

FIG. 3 shows the results of measuring the mechanical strength of the cast product thus cast. In addition to the case in which the filter is installed in the runner as in this example, Fig. 3 shows two cases in which there is no filter and a case in which the filter is installed in the sleeve for comparison. This figure shows the results of a tensile test performed by cutting out four test pieces for each cast product cast using the top-pouring method. That is, each bar graph shows the dispersion of eight measured values. Note that the deviation of each characteristic value is shown at the bottom of the figure, and the average value is shown in the figure.

As is clear from FIG. 2, the cast product of this example has extremely superior tensile strength and elongation, and has high yield strength, compared to the case where there is no filter or the case where a filter is provided on the sleeve.

In addition, as a result of casting a valve using the method of the present invention using J I 5AC8C alloy and performing T6 heat treatment after casting, no blistering occurred during heat treatment and the tensile strength was 37.
We were able to produce a high-strength cast product with a weight of 100 kg/+u+”.

[Effects of the Invention] According to the present invention, a filter is provided in the runner leading from the sleeve member to the cavity, and the molten metal is filtered immediately before being poured into the cavity, so that the molten metal from which the solidified layer or oxides have been removed provides a healthy casting. Products can be manufactured. Therefore, even if heat treatment is applied in a post-process, blistering and the like will not occur, and a high-strength cast product can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 (
FIG. 3 is a graph showing the effects of the present invention.

Claims (1)

[Claims] (1) A casting mold in which a cavity and runner of a predetermined shape are formed, a sleeve member communicating with the runner, a chip inserted into the sleeve member, and a hot water supply port provided in the sleeve member. A molten metal supply means for supplying molten metal into the sleeve member, a driving means for moving the tip forward and injecting the molten metal in the sleeve into the cavity through the runner, and a filter interposed in the runner. 1. A manufacturing device for a heat treatment casting, characterized by having a member.