JP4273963B2 - Die casting mold and die casting method - Google Patents

Description

  The present invention relates to a die casting die configured by communicating a cavity and a runner through a plurality of gates and a configuration of a die casting method.

In general, die casting is performed by rapidly injecting molten metal from a runner of a die casting mold into a cavity through a gate. As a die casting method, for example, there is a casting method as described in Patent Document 1.
Die casting cast by such a casting method has high dimensional accuracy and can be mass-produced.

Also, as described in Patent Document 2, as a die casting method, there is a method of injecting a semi-molten alloy material in which a solid phase portion and a liquid phase portion are mixed.
Normally, metal parts manufactured by die casting using aluminum or the like as a raw material have a uniform composition between the surface portion and the inside. However, in the casting method shown in Patent Document 2, a solid phase is formed by a filter disposed in a cavity of a mold. The layer is trapped, and a layer composed of only the liquid phase portion is locally formed on a part of the cast molded part.

JP-A-8-257722 JP-A-9-99353

  As described above, in die casting, since molten metal is injected at a high speed, it is difficult to control the flow of molten metal from each gate into the cavity. As a result, the flow rate of the molten metal injected from each gate becomes uneven, and at the gate portion where the flow velocity of the molten metal is large, gas defects due to entrainment of air, and hot water and hot water boundaries due to lowering of the molten metal temperature occur in the product. Quality may be reduced.

It is necessary to control the flow of the molten metal into the cavity in order to suppress the occurrence of such gas defects and hot water / borders. However, as a method of controlling the molten metal flow, It is conceivable to reduce the flow rate by providing a filter at the gate portion where the flow rate is large.
Therefore, in the present invention, a filter for reducing the flow rate of the molten metal is installed in the gate portion to control the flow of the molten metal, and it is possible to prevent the occurrence of defects such as gas defects, water wrinkles, and hot water boundaries. A mold is provided.
In Patent Document 2, a filter is installed in a cavity, and material characteristics differ depending on the part, such as a part where a solid phase part and a liquid phase part are mixed in a molded part and a part consisting only of the liquid phase part. A mold that can mold molded parts is disclosed, but a filter is installed at the gate to control the flow of the molten metal and prevent defects such as gas defects, water wrinkles, and hot water boundaries. Different.

A die casting mold for solving the above problems has the following characteristics.
That is, as described in claim 1, a die-casting die configured by connecting a cavity and a runner by a plurality of gates, and is manufactured separately from the die-casting die at a plurality of gate portions . A filter for decreasing the flow rate of the molten metal was installed, and the porosity of each filter was set to a different porosity, so that the flow rate of the molten metal in each gate portion was made uniform .
By installing a filter in the gate where the flow rate of the molten metal is fast, the flow rate of the molten metal is reduced to reduce the entrainment of air, such as gas nests, hot water wrinkles, hot water boundaries, liver balls, etc. It is possible to suppress the occurrence of casting defects due to hot water.
Also, the flow rate of the molten metal can be controlled simply by installing a filter at the gate, and can be easily performed without modifying the die casting mold such as changing the cross-sectional area of the gate. it can.
In addition, the turbulence of the molten metal in the cavity is reduced, the vorticity of the flow and the entrainment of air are reduced, and the occurrence of casting defects caused by hot water such as gas nests, hot water boundaries and liver balls is prevented. Is possible.
Moreover, since the filter to be installed is separate from the die casting die, it can be easily attached and detached by a robot or the like.

Further, the constituent component of the filter is the same component as the molten metal component .
Accordingly, the flow rate of the molten metal in the gate 13 can be improved in the later stage of injection while the flow rate of the molten metal is reliably controlled in the early stage of injection.
Further, the cast parts can be easily recycled, and the filter can be configured at low cost.

According to a third aspect of the present invention, there is provided a die casting method in which a cavity and a runner are connected by a plurality of gates, and a molten metal is injected from the runner into the cavity through the gates. A different filter is installed to control the molten metal flow rate at the gate portion to be uniform .
By installing a filter in the gate where the flow rate of the molten metal is fast, the flow rate of the molten metal is reduced to reduce the entrainment of air, such as gas nests, hot water wrinkles, hot water boundaries, liver balls, etc. It is possible to suppress the occurrence of casting defects due to hot water.
In particular, by installing multiple filters with different porosity, the turbulent flow of the molten metal in the cavity is reduced, the vorticity of the flow and the entrainment of air are reduced, and the gas nest, hot water boundary, liver ball, etc. It is possible to prevent the occurrence of casting defects due to the hot water.
Also, the flow rate of the molten metal can be controlled simply by installing a filter at the gate, and can be easily performed without modifying the die casting mold such as changing the cross-sectional area of the gate. it can.

According to the present invention, turbulence and air entrainment when molten metal is injected are reduced, and casting defects caused by hot water such as gas nests, hot water wrinkles, hot water boundaries, liver balls, etc. are found in the cast die casting. Occurrence can be suppressed.
Further, the flow rate of the molten metal can be easily controlled without modifying the die casting mold such as changing the cross-sectional area of the gate.
Further, the cast parts can be easily recycled, and the filter can be configured at low cost.

Next, modes for carrying out the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a die casting mold 1 according to the present invention.
The die casting mold 1 is configured by connecting a cavity 11 and a runner 12 with a plurality of gates 13, 13..., And molten metal is passed from the runner 12 through the gates 13, 13. A die-cast product is cast by high-speed injection into the inside.

  A filter 15 is provided in any one or more of the gates 13. The filter 15 reduces the flow velocity (flow rate) of the molten metal that passes through the gate 13 from the runner 12 and is injected into the cavity 11. In the case of this example, the filter 15 is manufactured separately from the die casting mold.

For example, in the case of this example, the filter 15 is installed in the cavity 13 disposed on the most distal end side 12 a of the runner 12.
For example, as shown in FIG. 2, the filter 15 is housed in the recess 13 a of the gate 13 while being sandwiched between the fixed mold 1 a and the movable mold 1 b of the die casting mold 1.

In this example, the filter 15 is installed in the gate 13 arranged on the most distal end side 12a of the runner 12 for the following reason.
That is, as shown in FIG. 3, in the state where the filter 15 is not installed, the flow rate of the molten metal passing through the gate 13 becomes faster from the base end side 12b of the runner 12 toward the front end side 12a. The flow velocity at the gate 13 on the part side 12a tends to be the fastest.

  In this way, if the flow rate of the molten metal injected from the gate 13 on the most advanced portion side 12a is too high, air is entrained when the molten material flows into the cavity 11, or the molten metal from the gate 13 on the most advanced portion side 12a. Therefore, casting defects caused by hot water such as gas nests, hot water wrinkles, hot water boundaries, and liver balls are likely to occur in the cast die-cast product.

Therefore, in particular, by installing the filter 15 at the gate 13 on the most advanced portion side 12a where the flow rate of the molten metal becomes high, the flow rate of the molten metal is decreased to reduce the entrainment of air and to suppress the occurrence of these defects. Yes. In this case, the porosity of the filter 15 is set so that the flow rate of the molten metal is an appropriate flow rate that does not cause air entrainment.
The flow rate of the molten metal can be controlled simply by installing the filter 15 on the gate 13 and can be easily performed without modifying the die casting mold 1 such as changing the cross-sectional area of the gate 13. be able to.

As shown in FIG. 4, the filter 15 can be installed at a plurality of gates 13, 13... So that the flow rate of the molten metal at each gate 13 is uniform.
Specifically, the porosity of each filter 15 is set to a different porosity depending on the flow rate of the installed gate 13 so that the molten metal flow rate of each gate 13 is uniform. That is, by varying the porosity of the filter 15, the flow path resistance of each gate 13 is changed to control the flow rate / flow rate of the molten metal.
In the case of this example, the porosity of each filter 15 is varied so as to gradually decrease from the base end side 12b of the runner 12 to the front end side 12a.

  In this way, by installing the filters 15 in the plurality of gates 13, 13... And setting the porosity of each filter 15 to a different porosity, the flow rate of the molten metal in each gate 13 portion is made uniform. The turbulence of the molten metal in the cavity 11 is reduced, the vorticity of the flow and the entrainment of air are reduced, and the occurrence of casting defects due to the hot water such as gas nests, hot water boundaries and liver balls is prevented. Is possible.

Moreover, the filter 15 is comprised with the component same as the component of the molten metal which shape | molds a die-cast product. For example, when the die-cast product to be molded is an aluminum die-cast product, a filter made of aluminum is also used as the filter 15.
Thus, since the component of the filter 15 is the same component as the molten metal component, the porosity of the filter 15 is the same as the set porosity at the initial stage of injection of the molten metal. (Flow rate) can be suppressed, and it is possible to reliably prevent the occurrence of casting defects caused by hot water such as a defective ball due to the previous run of molten metal.

If injection of the molten metal is continued from this state, the filter 15 starts to melt due to the temperature of the molten metal, and the porosity of the filter 15 gradually increases from the initial state. In other words, the porosity of the filter 15 increases because the filter 15 melts (or fuses) with the molten metal to be injected.
As a result, the flow resistance of the gate 13 where the filter 15 is installed can be reduced and the hot water flow of the gate 13 can be improved.

Defects such as gas nests, hot water boundaries, and hemispheres that occur due to the entrainment of air due to the flow rate of the molten metal appear only in the early stage of injection of the molten metal. It is desirable that the flow path resistance of the gate 13 is made as small as possible to quickly fill the cavity 11 with the molten metal.
Therefore, as described above, the filter 15 is composed of the same components as the components of the molten metal so that the molten metal flow rate of the gate 13 is improved in the late stage of injection while the flow rate of the molten metal is reliably controlled in the early stage of injection. ing.

Moreover, the filter 15 comprised with the component same as the component of a molten metal solidifies the thing which prepared the particle size of the chip which generate | occur | produces at the time of the machining of the molded product shape | molded with the die 1 for die castings by high pressure, for example. Can be produced.
By manufacturing the filter 15 in this way, the cast parts can be easily recycled, and the filter 15 can be configured at low cost.

The porosity of the filter 15 configured by compressing the chips can be easily changed by adjusting the pressure at the time of compacting. For example, the filter 15 having a porosity of 30% to 80% is configured. be able to.
The filter 15 can also be made of foam metal or the like. The filter 15 is preferably a three-dimensional structure filter.
In addition, the filter 15 manufactured as a separate part can be attached to or removed from the gate 13 of the die casting die 1 with an industrial robot or the like.

  The die casting mold 1 provided with the filter 15 can be configured as a mold for casting a cylinder block of an engine, for example. In addition, it can also be configured as a mold for die-casting large and thin cases that are difficult to cast and body frame parts of vehicles.

It is a plane sectional view showing the flow rate of the molten metal in each gate in the die casting die of the present invention which installed the filter in the gate. It is side surface sectional drawing which shows the filter installed in the gate of the die-casting metal mold | die. It is a top sectional view showing the flow rate of the molten metal at each gate when no filter is installed at the gate. It is a plane sectional view showing a die-casting die in which a filter is installed in a plurality of gates and the flow rate of the molten metal at each gate is made uniform.

1 Die casting mold 11 Cavity 12 Runner 13 Gate 15 Filter

Claims (3)

A die-casting die configured by connecting a cavity and a runner with a plurality of gates,
A filter that reduces the flow rate of the molten metal, which is manufactured separately from the die casting die, is installed in a plurality of gate parts, and the porosity of each filter is set to a different porosity, so that the molten metal of each gate part is set. Die casting mold characterized by uniform flow velocity . 2. The die casting mold according to claim 1, wherein the constituent component of the filter is the same component as the molten metal component . In the die casting method in which the cavity and the runner are connected by a plurality of gates, and the molten metal is injected from the runner into the cavity through the gate,
A die casting method, wherein a plurality of filters having different porosity are installed in the plurality of gates, and the flow rate of the molten metal in the gate portion is controlled uniformly .

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