JP2009195970A - Low pressure casting method and low pressure casting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low pressure casting method and a low pressure casting device with a simple constitution which can surely achieve the directive solidification of a molten metal, and a casting free from defects can be efficiently molded. <P>SOLUTION: The low pressure casting device includes: a holding furnace 1 holding a molten metal M; a mold 2 arranged at the upper part of the holding furnace 1; a stroke 3 provided at the mold 2 and whose lower tip is dipped into the molten metal M held to the holding furnace 1; and a molten metal pushing-up means 4 feeding a pressurized fluid into the holding furnace 1, pushing up the molten metal M via the stroke 3 and filling the molten metal M into the mold 2. At the initial stage of pouring, a low temperature molten metal MA is fed into the mold 2, and a high temperature molten metal MB is fed into the mold 2 from the middle of the pouring. The temperature of the low temperature molten metal MA is held to the one lower than that of the high temperature molten metal MB, and further, it is contacted with the cavity 22 of the mold 2 whose temperature is low, thus directive solidification that the solidification of the molten metal M successively progresses from the tip part within the cavity 22 toward a pouring opening 23 can be achieved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a low-pressure casting method and a low-pressure casting apparatus, and more specifically, by supplying a pressurized fluid into a holding furnace in which the molten metal is held, the molten metal is pushed up via stalk and disposed above the holding furnace. A low pressure casting method for pouring molten metal into the mold, a holding furnace for holding the molten metal, a mold disposed on the holding furnace, and a molten metal provided in the mold and held in the holding furnace has a lower end. The present invention relates to a low pressure casting apparatus having a stalk to be immersed, and a molten metal push-up means for supplying a pressurized fluid into a holding furnace and pushing up the molten metal through the stalk to fill a mold.

  For example, a low-pressure casting method is widely used as one method for casting a product (including a rough shape) made of an aluminum alloy such as an engine cylinder head of an automobile. Generally, in the low pressure casting method, a mold is placed on a holding furnace holding a molten metal, the lower end of the stalk provided on the mold is immersed in the molten metal of the holding furnace, and the inside of the holding furnace is pressurized through the stalk. The molten metal is pushed up into the mold and filled, and the molten metal is solidified by holding the molten metal to form a product having a predetermined shape.

  Patent Document 1 is known as a conventional technique for such a low-pressure casting method. Patent Document 1 relates to a casting method and a casting apparatus aiming to perform uniform casting by keeping the temperature of the molten metal fed into the mold constant and changing the molten metal feeding pressure along a predetermined pattern. There is (0001).

  In Patent Document 1, in a method of feeding a molten metal to a mold through a feeding device that has been put into a holding furnace, an inert gas is press-fitted into an upper portion of a feeding tank of the feeding device, When the molten metal is pressed into the molten metal, the molten metal pressure is kept constant, the molten metal pressure is fed by a predetermined pressure pattern, and the molten metal temperature and pressure to the mold are controlled. A featured casting method is disclosed.

  In Patent Document 1, a feeding device is installed in a holding furnace, a partition wall is provided in the feeding tank of the feeding device to make a constant hot water surface, and the partition wall is partitioned by the partition wall. Inserting and installing the feeding cylinder into the mold into the pressure chamber, providing the melt inflow means on one side of the pressurizing chamber, installing the pressurizing means at the top, and further providing the heating means in the feeding cylinder A casting apparatus characterized by the above is disclosed.

  By the way, when the molten metal filled in the mold is solidified, shrinkage holes that become casting defects or gas pores are generated. In view of this, it has been conventionally known that directional solidification is performed as a technique for collecting the shrinkage holes and gas pores in the pouring gate by sequentially advancing the solidification of the molten metal from the portion far from the pouring gate in the cavity toward the pouring gate. In general, the temperature of the mold and stalk is lower than that of the molten metal, particularly in the initial stage of pouring, so that the temperature of the molten metal filled in the mold becomes lower in the initial stage of pouring, and in the mold later in the pouring. The temperature of the molten metal filled in is maintained at a high level, that is, there is a temperature difference between the molten metal at the start and completion of the pouring. This temperature difference is due to the fact that the low temperature molten metal filled in the initial stage of pouring flows to a position far from the pouring gate and solidifies, and the molten metal at the time of pouring is hot and solidification is delayed. Effective for coagulation.

JP 2005-95921 A

  The above-mentioned Patent Document 1 is intended to make the temperature of the molten metal fed into the mold constant, and as described above, the temperature difference between when the molten metal starts pouring and when the pouring is completed. Is only due to the temperature of the mold and stalk, and if the temperature difference is insufficient, directional solidification of the molten metal cannot be achieved, and defects due to solidification shrinkage may occur inside the cast product, There was a problem that it was difficult to improve the yield.

  In order to prevent such defects due to lack of temperature difference, it is necessary to increase the temperature of the molten metal poured from the holding furnace to the mold through the stalk or to extend the pressurizing time of the molten metal. there were. When the temperature of the molten metal is increased, it takes time to solidify, and one molding cycle becomes longer, and there is a problem that it is difficult to improve efficiency, such as increasing energy for maintaining the molten metal at a set temperature. . Moreover, even when the molten metal pressurization time is extended, there is a problem that it is difficult to improve efficiency, for example, one molding cycle becomes longer and energy for pressurizing the molten metal increases.

  The present invention has been made in view of the above-described problems. The low-pressure casting method and the low-pressure casting apparatus are capable of reliably directional solidification of a molten metal with a simple configuration and efficiently forming a defect-free casting. The purpose is to provide.

In order to achieve the above object, the low pressure casting method according to the first aspect of the present invention supplies the pressurized fluid into the holding furnace in which the molten metal is held, thereby pushing up the molten metal through the stalk and above the holding furnace. This is a low-pressure casting method in which molten metal is poured into a mold that has been placed. Prepare molten metal at different temperatures, supply low-temperature molten metal into the mold at the beginning of pouring, and then heat the molten metal from the middle of the molten metal to the mold. It is characterized by being supplied inside.
In order to achieve the above object, a low pressure casting apparatus according to a second aspect of the invention provides a holding furnace for holding a molten metal, a mold disposed on the holding furnace, and a holding furnace provided in the mold. A low-pressure casting apparatus comprising: a stalk whose lower end is immersed in the molten metal; and a molten metal push-up means for supplying a pressurized fluid into a holding furnace to push up the molten metal through the stalk and filling the mold. The holding furnace is configured to be able to hold molten metal at different temperatures, and the lower portion of the stalk is branched so that the lower end of the stalk is immersed in the molten metal at different temperatures held in the holding furnace. The molten metal push-up means first pushes up the low-temperature molten metal held in the holding furnace and supplies it into the mold, and then pushes up the high-temperature molten metal in the mold. To supply It is to being a shall.

According to the first aspect of the present invention, the molten metal having different temperatures is prepared, the low-temperature molten metal is supplied into the mold in the initial stage of pouring, and the high-temperature molten metal is switched and supplied from the middle of the molten metal into the mold. The low-temperature molten metal supplied at the beginning of pouring flows to a position far from the pouring gate in the mold to start solidification, and the hot molten metal switched and fed from the middle of pouring gradually solidifies toward the pouring gate in the mold. Directional coagulation is ensured. Therefore, it is possible to provide a low-pressure casting method that can efficiently form a defect-free casting.
Moreover, in invention of Claim 2, each lower end of the stalk branched into the molten metal of the different temperature hold | maintained at the holding furnace is immersed, and among the molten metal of the different temperature hold | maintained in the holding furnace by the molten metal pushing-up means, First, the low-temperature molten metal is pushed up and supplied into the mold, and then the low-temperature molten metal is switched to push up the high-temperature molten metal and supplied into the mold. As a result, the initially supplied low-temperature molten metal flows to a position far from the pouring gate in the mold to start solidification, and the hot molten metal switched and supplied from the middle of pouring gradually solidifies toward the pouring gate in the mold. Directional coagulation is ensured. Therefore, it is possible to provide a low-pressure casting apparatus that can efficiently form a casting without defects.

(Aspect of the Invention)
In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following items, item (1) corresponds to claim 1, and item (3) corresponds to claim 2.

(1) A low pressure casting method in which a pressurized fluid is supplied into a holding furnace in which the molten metal is held to push up the molten metal through stalk and to pour the molten metal into a mold disposed above the holding furnace. And
Prepare molten metal at different temperatures,
A low-pressure casting method characterized in that a low-temperature molten metal is supplied into a mold at an initial stage of pouring, and a high-temperature molten metal is supplied into the mold from the middle of pouring.

  In the invention described in the item (1), by preparing melts with different temperatures, supplying a low-temperature melt into the mold in the initial stage of pouring, and switching and feeding the high-temperature melt into the mold from the middle of the pouring The low-temperature molten metal supplied at the beginning of pouring flows to a position far from the pouring gate in the mold to start solidification, and the hot molten metal switched and fed from the middle of pouring gradually solidifies toward the pouring gate in the mold. Therefore, directional solidification can be achieved with certainty, and therefore, a casting having no defect can be efficiently formed.

(2) The holding furnace is divided into a low temperature side holding furnace and a high temperature side holding furnace,
The lower part of the stalk is immersed in molten metal at different temperatures in each molten metal holding furnace, and the upper part thereof is joined and connected to the mold,
With the pressurized fluid supplied to the high temperature side holding furnace, the pressurized fluid is supplied into the low temperature side holding furnace, and the low temperature molten metal is pushed up and supplied from the low temperature side holding furnace to the mold. The pressurized fluid is supplied into the low temperature side holding furnace from the high temperature side holding furnace, and the high temperature molten metal is pushed up and supplied from the high temperature side holding furnace to the mold. The low-pressure casting method according to item 1).

  In the invention of the item (2), in the invention described in the item (1), the holding furnace is divided into a low-temperature side holding furnace and a high-temperature side holding furnace, and the stalk has a lower portion of each molten metal holding furnace. In the state where the pressurized fluid is supplied to the high temperature side holding furnace, it is soaked in the molten metal at different temperatures, and the upper part thereof is joined and connected to the mold. The pressurized fluid is supplied, the low temperature molten metal is pushed up and supplied from the low temperature holding furnace to the mold, and then the pressurized fluid is supplied into the low temperature holding furnace from the middle of pouring. By supplying a pressurized fluid into the mold and pushing and feeding the high-temperature molten metal from the high-temperature side holding furnace to the mold, the directional solidification can be surely achieved, and therefore, a defect-free casting is efficiently formed. be able to.

(3) A holding furnace for holding the molten metal, a mold disposed on the holding furnace, stalk having a lower end immersed in the molten metal provided in the mold and held in the holding furnace, and pressurizing in the holding furnace A low-pressure casting apparatus having a molten metal push-up means for supplying a fluid and pushing up the molten metal through the stalk to fill the mold,
The holding furnace is configured to hold molten metal at different temperatures,
The stalk is configured such that the lower part branches so that the lower end thereof is immersed in molten metal of different temperatures held in the holding furnace, respectively.
The molten metal push-up means first pushes up a low-temperature molten metal held in the holding furnace and supplies it into the mold, and then pushes up the high-temperature molten metal into the mold. A low pressure casting apparatus characterized by being.

  In the invention of the item (3), the lower ends of the stalks branched into the melts of different temperatures held in the holding furnace are respectively immersed, and among the melts of different temperatures held in the holding furnace by the molten metal push-up means, Then, the low temperature molten metal is pushed up and supplied into the mold, and then the low temperature molten metal is switched to supply the high temperature molten metal into the mold. As a result, the initially supplied low-temperature molten metal flows to a position far from the pouring gate in the mold to start solidification, and the hot molten metal switched and supplied from the middle of pouring gradually solidifies toward the pouring gate in the mold. Directional coagulation is ensured. Therefore, it is possible to efficiently mold a cast product having no defect.

  (4) The low pressure casting according to (3), wherein the holding furnace is divided into a low temperature side holding furnace and a high temperature side holding furnace because a partition wall is provided therein. apparatus.

  In the invention of the item (4), in the invention described in the item (3), a partition wall is provided inside the holding furnace and divided into a low-temperature side holding furnace and a high-temperature side holding furnace, so that molten metals having different temperatures can be reliably obtained. Can be held separately.

First, an embodiment of a low-pressure casting apparatus according to the present invention will be described with reference to FIG. The same reference numerals indicate similar or corresponding parts.
The low pressure casting apparatus of the present invention generally includes a holding furnace 1 for holding a molten metal M, a mold 2 disposed on the holding furnace 1, and a molten metal M provided in the mold 2 and held in the holding furnace 1. A stalk 3 having a lower end immersed therein and a molten metal push-up means 4 for supplying a pressurized fluid into the holding furnace 1 and pushing up the molten metal M through the stalk 3 to fill the mold 2 are provided.
And the holding furnace 1 in this embodiment is divided into the low temperature side holding furnace 1A and the high temperature side holding furnace 1B by providing the partition wall 10 inside thereof, and the molten metal MA, having different temperatures, Each MB can be held.
Further, the lower part 3A, 3B is branched so that the lower end of the stalk 3 is immersed in the molten metals MA, MB having different temperatures respectively held in the low temperature side holding furnace 1A and the high temperature side holding furnace 1B. Yes.
The molten metal push-up means 4 first pushes up the low-temperature molten metal MA among the molten metals MA and MB held in the holding furnace 1 and supplies them into the mold 2, and then switches from the low-temperature molten metal MA. The high-temperature molten metal MB is pushed up and supplied into the mold 2.

  In this embodiment, heating means 11A and 11B are respectively provided below the holding furnace 1 corresponding to the low temperature side holding furnace 1A and the high temperature side holding furnace 1B which are divided by the partition wall 10. The outputs of the heating means 11A and 11B are set so that the low temperature molten metal MA and the high temperature molten metal MB can be held at the set temperatures, respectively. And as the molten metal M of different temperature, the low temperature molten metal MA and the high temperature molten metal MB are prepared, and are hold | maintained at the low temperature side holding furnace 1A and the high temperature side holding furnace 1B, respectively. The upper opening of the holding furnace 1 is provided with a support base 12 and is closed. The holding furnace 1 is also provided with a hot water supply port for supplying the molten metal M supplied from the melting furnace. Above the low temperature side holding furnace 1A and the high temperature side holding furnace 1B, air supply units 4A and 4B to which the molten metal push-up means 4 are connected are provided.

  The mold 2 includes a lower mold 20 attached on the support base 12 and an upper mold 21 that is opened and closed with respect to the lower mold 20. A cavity 22 is formed in the mold 2 in a state where the lower mold 20 and the upper mold 21 are closed, corresponding to the shape of the cast product to be molded. The lower mold 20 is formed with a gate 23 for communicating the cavity 22 and the stalk 3.

  The stalk 3 is divided into two parts 3A and 3B (in the case of this embodiment) so that the lower part thereof is disposed in the low temperature side holding furnace 1A and the high temperature side holding furnace 1B, respectively. The parts 3C are combined to form a single unit. The lower ends of the lower portions 3A and 3B are positioned so as to be immersed in the molten metals MA and MB respectively held in the low temperature side holding furnace 1A and the high temperature side holding furnace 1B. The upper portion 3 </ b> C is connected to the gate 23 of the cavity 22 of the mold 2.

  The molten metal push-up means 4 pumps the pressurized fluid 40 made of gas such as air or inert gas from the supply parts 4A and 4B into the low temperature side holding furnace 1A and the high temperature side holding furnace 1B so that the pressure and volume can be controlled. Therefore, the pressurized fluid 40 can be switched between the pumping and stopping at an arbitrary timing. By adjusting the pressure and volume at which the pressurized fluid 40 is pumped, the low temperature molten furnace MA and the high temperature molten metal MB held in the low temperature side holding furnace 1A and the high temperature side holding furnace 1B are pushed up from the lower portions 3A and 3B of the stalk 3. The height (volume), the supply pressure of the molten metal M into the cavity 22 and the like can be adjusted. The low temperature molten metal MA held in the low temperature side holding furnace 1A and the high temperature side holding furnace 1B is controlled by controlling the pumping and stopping of the pressurized fluid 40 by the molten metal push-up means 4 and the adjustment of the pressure and volume at the time of pumping. And the high temperature molten metal MB can be pushed up and supplied into the cavity 22 at an arbitrary timing. This control will be described in detail later.

  Note that the present invention is not limited to this embodiment. For example, without providing the partition wall 10 in the single holding furnace 1 to form the low-temperature side holding furnace 1A and the high-temperature side holding furnace 1B, the holding furnaces are individually composed of a low-temperature molten metal holding furnace and a high-temperature molten metal holding furnace. It can also be provided. Further, the holding furnace 1 for holding the molten metal M at different temperatures is not limited to the molten metal divided into two temperature sections of low temperature and high temperature, and more, such as holding a medium temperature molten metal between the low temperature and the high temperature. It is also possible to configure such that the molten metal can be held at different temperature ranges or at different continuous temperatures.

Next, an embodiment of the low-pressure casting method of the present invention will be described in detail together with its operation based on FIGS. 1 to 4 depending on the case of using the low-pressure casting apparatus configured as described above.
In the present invention, generally, the pressurized fluid 40 is supplied into the holding furnace 1 in which the molten metal M is held, so that the molten metal M is pushed up through the stalk 3 and is placed in the mold 2 disposed above the holding furnace 1. A low-pressure casting method for pouring molten metal M, preparing molten metals MA and MB of different temperatures, and supplying low-temperature molten metal MA into mold 2 at the initial stage of pouring of molten metals MA and MB of different temperatures, The high temperature molten metal MB is supplied into the mold 2 from the middle of pouring.
In this embodiment, the holding furnace 1 is divided into the low temperature side holding furnace 1A and the high temperature side holding furnace 1B so that the molten metals MA and MB having different temperatures can be held, and the stalk 3 is The lower portions 3A and 3B are immersed in the melts MA and MB having different temperatures in the low temperature side holding furnace 1A and the high temperature side holding furnace 1B, respectively, and the upper portions 3C are joined and connected to the cavity 22 of the mold 2. In the state where the pressurized fluid 40 is supplied to the high temperature side holding furnace 1B at a predetermined pressure, the pressurized fluid 40 is supplied into the low temperature side holding furnace 1A, and the casting mold is sent from the low temperature side holding furnace 1A to the mold. In the state where the low temperature molten metal MA is pushed up and supplied to the cavity 22 in the inner wall 2 and then the pressurized fluid 40 is supplied at a predetermined pressure into the low temperature side holding furnace 1B from the middle of pouring, inside the high temperature side holding furnace 1B. Supply pressurized fluid 40 to And supplies push hot melt MB from the high temperature side holding furnace 1B in the cavity 22 of the mold 2.

  In casting a cast product, a casting apparatus having the above-described configuration is prepared, and the molten metal M is supplied to the low temperature side holding furnace 1A and the high temperature side holding furnace 1B, respectively, and set by the heating means 11A and 11B. Held at a low temperature as a low-temperature molten metal MA and a high-temperature molten metal MB. Then, as shown at time A in FIG. 1 and FIG. 4, the pressurized fluid 40 is uniformly supplied to the low temperature side holding furnace 1A and the high temperature side holding furnace 1B through the intake portions 4A and 4B by the molten metal push-up means 4, respectively. Then, the low-temperature molten metal MA and the high-temperature molten metal MB are respectively pushed up slightly below the Stoke branch (merging portion) 3D.

  In addition, the mold 2 is closed with the upper mold 11B approaching the lower mold 11A. At this time, as for the casting_mold | template 2, the lower mold | type 11A is 470-500 degreeC, and the upper mold | type 11B is 270-300 degreeC, for example. Although the temperature of the molten metal M held in the holding furnace 1 varies depending on the material and the like, for example, in the case of the material A, the low temperature molten metal MA is 670 to 690 ° C., the high temperature molten metal MB is 700 to 730 ° C., and the material B In the case of the material C, the low temperature molten metal MA is 650 to 670 ° C. and the high temperature molten metal MB is 680 to 710 ° C. In the case of the material C, the low temperature molten metal MA is 680 to 700 ° C. and the high temperature molten metal MB is maintained at 710 to 740 ° C. Yes. In any case, the low temperature molten metal MA is in the range of 20 ° C., the high temperature molten metal MB is in the range of 30 ° C., and the low temperature molten metal MA and the high temperature molten metal MB are preferably at a temperature difference of 10 to 60 ° C. Is set at a temperature difference of 30 to 40 ° C.

  From this state, as shown at time B in FIGS. 2 and 4, the pressurized fluid 40 is supplied into the low temperature side holding furnace 1A by the molten metal push-up means 4, and the cavity 22 in the mold 2 is supplied from the low temperature side holding furnace 1A. A predetermined amount of low-temperature molten metal MA is pushed up and supplied. At this time, in order to prevent the low temperature molten metal MA from flowing from the lower portion 3A on the low temperature side of the stalk 3 into the lower portion 3B on the high temperature side, the high temperature side holding furnace 1B has a high temperature molten metal against the pushing pressure of the low pressure molten metal MA. The pressurized fluid 40 is supplied at such a pressure that the MB is pushed up and maintained up to the branch point (merging point) 3D. As a result, as shown in FIG. 4B, the cavity 22 of the mold 2 is surely filled with the low-temperature molten metal MA first.

  Subsequently, as shown at time C in FIGS. 3 and 4, the pressurized fluid 40 is switched and supplied from the low temperature side holding furnace 1A into the high temperature side holding furnace 1B by the molten metal push-up means 4, and the high temperature side holding furnace 1B. The hot melt MB is pushed up and supplied to the cavity 22 in the mold 2 by a predetermined amount. At this time, in order to prevent the high temperature molten metal MB from flowing from the lower portion 3B on the high temperature side of the stalk 3 into the lower portion 3A on the low temperature side, the low temperature side holding furnace 1A has a low temperature molten metal against the push-up pressure of the high temperature molten metal MB. The pressurized fluid 40 is supplied at such a pressure that the MA is pushed up and maintained up to the branch point (confluence point) 3D. As a result, as shown in FIG. 4C, the cavity 22 of the mold 2 is surely switched and filled with the high-temperature molten metal MB from the middle following the previously filled low-temperature molten metal MA.

  Then, as shown in FIG. 4D and time D, when the filling of the predetermined amount of high-temperature molten metal MB into the cavity 22 of the mold 2 is completed, the molten metal M is solidified until a cast product is formed. The molten metal push-up means 4 pressurizes the pressurized fluid 40 into the low temperature side holding furnace 1 </ b> A and the high temperature side holding furnace 1 </ b> B with a substantially uniform pressure to hold the pressure.

  At this time, in the cavity 22 of the mold 2, the high-temperature molten metal MB is supplied from the middle, so that the previously supplied low-temperature molten metal MA flows toward a portion far from the gate 23 in the cavity. The low-temperature molten metal MA is held at a temperature lower than that of the high-temperature molten metal MB supplied later, and is in contact with the cavity 22 of the mold 2 having a lower temperature, thereby being a portion far from the gate 23 in the cavity 22. The temperature is reliably lowered at the (tip portion) and solidification starts. In the middle of pouring, the high temperature molten metal MB is switched and supplied from the low temperature molten metal MA, so that the molten metal filled in the cavity 22 is solidified from the tip portion in the cavity 22 toward the pouring gate 23. Progress sequentially in a short time. Therefore, directional solidification in which shrinkage holes and gas pores of the casting are collected in the gate 23 can be surely achieved, casting defects can be prevented and yield can be improved, and time required for one molding cycle can be improved. The efficiency can be improved without lengthening.

It is sectional drawing shown in order to demonstrate one Embodiment of the low pressure casting apparatus of this invention. It is sectional drawing shown in order to demonstrate the state of the pouring initial stage which pushes up a low temperature molten metal and is supplied to a casting_mold | template. It is sectional drawing shown in order to demonstrate the state from the middle of the pouring which pushes up a high temperature molten metal and is supplied to a casting_mold | template. It is a figure for demonstrating the pressure change inside a low temperature side holding furnace and a high temperature side holding furnace.

Explanation of symbols

1: Holding furnace, 2: Mold, 3: Stoke, 3A, 3B: Lower part where Stoke branched, 4: Melt push-up means, 10: Partition, 11A: Low temperature side holding furnace, 11B: High temperature side holding furnace, 22: Cavity, 23: gate, 40: pressurized fluid

Claims (2)

A low pressure casting method in which a pressurized fluid is supplied into a holding furnace in which the molten metal is held to push up the molten metal through stalk, and the molten metal is poured into a mold disposed above the holding furnace,
Prepare molten metal at different temperatures,
A low-pressure casting method characterized in that a low-temperature molten metal is supplied into a mold at an initial stage of pouring, and a high-temperature molten metal is supplied into the mold from the middle of pouring. A holding furnace for holding molten metal, a mold disposed on the holding furnace, stalk having a lower end immersed in the molten metal provided in the mold and held in the holding furnace, and supplying pressurized fluid into the holding furnace And a low pressure casting apparatus having a molten metal push-up means for pushing up the molten metal through the stalk and filling the mold,
The holding furnace is configured to hold molten metal at different temperatures,
The stalk is configured such that the lower part branches so that the lower end thereof is immersed in molten metal of different temperatures held in the holding furnace, respectively.
The molten metal push-up means first pushes up a low-temperature molten metal held in the holding furnace and supplies it into the mold, and then pushes up the high-temperature molten metal into the mold. A low pressure casting apparatus characterized by being.

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