WO2021002441A1 - Low pressure casting device, and heater unit for low pressure casting device - Google Patents

Abstract

[Problem] To ensure durability by suppressing a rise in the temperature of a sealing terminal portion or wiring, even if an infrared lamp heater is used as a sub-stalk heating means. [Solution] In this low pressure casting device, a sub-stalk heating means consists of an infrared lamp heater 22 comprising a rod-shaped transverse straight portion 32 which is disposed in a heating space 17 formed around the sub-stalk and which includes carbon fiber filaments 37, and a sealing terminal portion 35 which is provided at the end of the transverse straight portion 32, and through which lead wires 38 that are electrically connected to the carbon fiber filaments 37 are led out, wherein: the heating space 17 is divided into an upper space 17A and a lower space 17B by means of a metal dividing plate 21 that includes a thermally insulating board 25; the infrared lamp heater 22 bends between the transverse straight portion 32 and the sealing terminal portion 35; and the transverse straight portion 32 and the sealing terminal portion 35 are respectively disposed in the upper space 17A and the lower space 17B.

Description

Heater unit for low-pressure casting equipment and low-pressure casting equipment

The present invention relates to a low-pressure casting apparatus in which a sub-stalk is arranged between a stalk inserted into a molten metal holding furnace and a mold provided above the stalk, and a heater unit used in the low-pressure casting apparatus.

In the low-pressure casting equipment, a mold consisting of an upper mold and a lower mold is installed above the molten metal holding furnace for storing molten metal such as aluminum alloy, and the lower end of the tubular stalk is inserted into the molten metal holding furnace. On the other hand, the upper end of the stalk is connected to the lower mold via the sub stalk. Here, when the molten metal holding furnace heated to a predetermined temperature is pressurized, the molten metal is filled in the cavity of the mold via stalk and sub-stalk and solidifies to obtain a predetermined cast product.
In such a low-pressure casting apparatus, the sub-stalk is heated at the time of casting so that the molten metal does not solidify (clogging the sprue) at the sprue portion of the lower die. As a heating means of this sub-stalk, a technique of using a gas burner or using an electric heater as disclosed in Patent Documents 1 and 2 is known.

Jikken 8-4204 Gazette Japanese Patent No. 3212208

In the case of a gas burner, since the flame directly hits the sub-stalk, heating tends to be uneven, it becomes difficult to stabilize the quality of the cast product, and there is a possibility that molten metal leakage may occur due to the distortion of the sub-stalk.
In addition, the number of man-hours required for ignition and thermal power adjustment increases, and the thermal power adjustment depends on the skill of the operator, so that there is a risk of temperature decrease due to misfire, which leads to a decrease in work efficiency.
Furthermore, since it is used in a narrow space, combustion cannot be maintained unless the air ratio is increased, and the amount of energy used increases due to constant combustion. In addition, the convective heat heats not only the sub-stalk but also the entire atmosphere, resulting in poor heating efficiency.

On the other hand, using an electric heater enables uniform heating, stabilizes quality, and prevents deterioration of work efficiency, so it is desirable as a heating means, but it is necessary to protect the sealing terminal and wiring from heat. Occurs. In particular, it is conceivable to adopt an infrared lamp heater as an electric heater that emits sufficient radiant heat in a high temperature atmosphere, but the life of this infrared lamp heater is significantly shortened when the temperature of the sealing terminal portion exceeds 350 ° C. Since the sub-stalk is heated in a high temperature atmosphere of 500 ° C. or higher, durability cannot be ensured unless measures are taken to keep the sealing terminal portion at 350 ° C. or lower. In addition, in order to protect the wiring from heat, proper protection cannot be performed unless the handling is taken into consideration.

Therefore, the present invention is for a low-voltage casting apparatus and a low-voltage casting apparatus capable of suppressing a temperature rise of a sealing terminal portion and wiring and ensuring durability even when an infrared lamp heater is used as a substalk heating means. The purpose is to provide a heater unit.

In order to achieve the above object, the invention according to claim 1 is made of a molten metal holding furnace, a stalk inserted in the molten metal holding furnace, and a stalk disposed above the stalk, from an upper mold and a lower mold. A low-pressure casting apparatus including a mold, a sub-stalk disposed between the stalk and the lower mold, and a heating means for heating the sub-stalk.
The heating means is arranged in a heating space formed around the sub-stalk, and is provided at a heating portion having a heating element and at the end of the heating portion, and is sealed to lead a lead wire electrically connected to the heating element. It is an infrared lamp heater consisting of terminals.
The heating space is divided into an upper space and a lower space by a metal partition member having a heat insulating layer.
The infrared lamp heater is characterized in that the heat generating portion and the sealing terminal portion are bent so that the heat generating portion is arranged in the upper space and the sealing terminal portion is arranged in the lower space.
According to the second aspect of the present invention, in the configuration of the first aspect, the infrared lamp heater is a rod-shaped body bent in an L shape, the heat generating portion is arranged sideways in the upper space, and the sealing terminal portion is below. It is characterized in that it is arranged downward in the side space.
According to the third aspect of the present invention, in the configuration of the first or second aspect, the heat generating portion of the infrared lamp heater is formed by enclosing a thin plate-shaped carbon fiber filament serving as a heating element in a glass tube and sandwiching the carbon fiber filament. However, on the opposite side of the sub-stalk, the outer surface of the glass tube is coated with an infrared reflective paint or a metal reflecting plate is arranged.
The invention according to claim 4 is characterized in that, in the configuration of claim 3, the carbon fiber filament is arranged in the glass tube in a posture in which the irradiation surface on the sub-stalk side faces diagonally upward.
The invention according to claim 5 is characterized in that, in any of the configurations of claims 1 to 4, an infrared absorbing material is applied to the outer surface of the sub-stalk.
The invention according to claim 6 comprises a lower mold die base that supports the lower mold and allows the sub-stalk to penetrate in any of the configurations of the first to fifth aspects, and a through hole for the sub-stalk in the lower mold die base. Is characterized in that it is formed larger than the outer shape of the sub-stalk and the lower mold is exposed in the upper space.
According to the invention of claim 7, in any of the configurations of claims 1 to 6, the partition member has a circular shape that surrounds the outside of the sub-stalk, and a plurality of infrared lamp heaters form the partition member along the circular shape. It is characterized by being supported by.
In order to achieve the above object, the invention according to claim 8 is made of a molten metal holding furnace, a stalk inserted in the molten metal holding furnace, and a stalk arranged above the stalk, from an upper mold and a lower mold. A heater unit for heating a sub-stalk, which is provided in a low-pressure casting apparatus including a mold and a sub-stalk arranged between the stalk and a lower mold.
A metal partition member that is arranged in the heating space formed around the sub-stalk and has a heat insulating layer to partition the heating space into an upper space and a lower space.
It has an infrared lamp heater including a heat generating portion having a heating element and a sealing terminal portion provided at an end of the heating element and leading out a lead wire electrically connected to the heating element.
The infrared lamp heater is characterized in that it is bent between the heat generating portion and the sealing terminal portion, and the heating portion is supported on the upper side of the partition member and the sealing terminal portion is supported on the lower side of the partition member. To do.

According to the inventions of claims 1 and 8, an infrared lamp heater is used as the heating means of the sub-stalk, and the heat generating portion of the infrared lamp heater is partitioned above the partition member having the heat insulating layer, and the sealing terminal portion is partitioned. Since they are arranged on the lower side of each member, even if an infrared lamp heater is used, the temperature rise of the sealing terminal portion and the wiring can be suppressed and the durability can be ensured. Further, since the wiring is led out to the lower space, the maneuverability is also improved.
According to the second aspect of the present invention, in addition to the above effects, the infrared lamp heater is formed into an L-shaped bent rod-shaped body, the heating portion is arranged sideways in the upper space, and the sealing terminal portion is on the lower side. Since it is arranged downward in the space, the sealing terminal portion can be reliably retracted into the lower space while the sub-stalk is effectively heated by the heating portion.
According to the invention of claim 3, in addition to the above effect, the heating portion of the infrared lamp heater is assumed to have the carbon fiber filament enclosed in a glass tube, and on the opposite side of the sub-radiation sandwiching the carbon fiber filament, Since the reflective paint is applied to the outer surface of the glass tube or the reflector is arranged, infrared rays that are easily absorbed by the sub-stalk can be effectively emitted. In addition, since the reflective paint and the reflector do not oxidize even at high temperatures, it is possible to prevent infrared rays from leaking, and improvement in heating efficiency can be expected.
According to the invention of claim 4, in addition to the above effect, since the carbon fiber filament is arranged in a posture in which the irradiation surface on the sub-stalk side faces diagonally upward, the sub has a distance from the infrared lamp heater. The upper and lower molds of the stalk are also irradiated with infrared rays and can be heated uniformly. Therefore, the quality of the cast product is stable.
According to the fifth aspect of the present invention, in addition to the above effects, since the infrared absorbing material is applied to the outer surface of the sub-stalk, the infrared absorbing rate of the sub-stalk is increased, which leads to an improvement in heating efficiency.
According to the invention of claim 6, in addition to the above effect, the through hole of the sub-stalk in the lower mold die base is formed larger than the outer shape of the sub-stalk to expose the lower mold in the upper space. Therefore, the upper part of the sub-stalk and the lower mold are easily irradiated with infrared rays, and the lower mold can be effectively heated. In addition, since a large upper space can be secured, the layout of the infrared lamp heater is not restricted and the installation can be performed easily.
According to the invention of claim 7, in addition to the above effect, the partition member has a frame shape surrounding the outside of the sub-stalk, and a plurality of infrared lamp heaters are supported by the partition member along the frame shape. , Substoke can be heated uniformly from the entire circumference.

It is explanatory drawing of the low pressure casting apparatus. It is a perspective view of a heater unit (the inside of an infrared lamp heater is omitted). It is a top view of a heater unit (the inside of an infrared lamp heater is omitted). (A) is a sectional view taken along line AA of FIG. 3, and (B) is a sectional view taken along line BB. It is a top view of the heater unit. It is a side view of a heater unit. FIG. 5 is a cross-sectional view taken along the line CC of FIG. It is explanatory drawing of the modification example using a reflector.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Overview of low-pressure casting equipment]
FIG. 1 is a cross-sectional view showing an example of a low-pressure casting apparatus. The low-pressure casting apparatus 1 includes a molten metal holding furnace 2, a mold 3 arranged on the upper side of the molten metal holding furnace 2, and a stalk 4 and a sub stalk 5 connecting the molten metal holding furnace 2 and the mold 3. Become.
The molten metal holding furnace 2 holds the molten metal in which a metal for casting such as an aluminum alloy is melted at a predetermined temperature (for example, 700 ° C.) by a heating means (not shown). The upper opening is closed by the lid body 6, and a gas such as air can be supplied from the pressurizing port 7 at a predetermined pressure.
The mold 3 has a lower mold 8 and an upper mold 9, and the lower mold 8 is horizontally supported above the lid 6 by a lower mold die base 10 installed above the molten metal holding furnace 2. Will be done. The upper mold 9 forms a cavity 11 with the lower mold 8, and can be brought into contact with and separated from the lower mold 8 by a drive mechanism (not shown).

The stalk 4 is a cylinder that is vertically supported by the lid 6 in the center of the molten metal holding furnace 2, and the lower end is inserted into the molten metal, while the upper end penetrates the lid 6 and opens upward. There is.
The sub-stalk 5 has a cylindrical portion 12 whose lower end is coupled to the upper end of the stalk 4, and an expanding portion 13 which expands in a rectangular shape in a plan view from the upper portion of the cylindrical portion 12. The expansion portion 13 has a connection port 15 on the upper surface, which is connected to a plurality of sprues 14 formed in the lower mold 8, and penetrates through a through hole 16 formed in the lower mold die base 10. It is bound to type 8. The through hole 16 is formed larger in the front-rear and left-right directions than the expansion portion 13, and exposes the lower surface of the lower mold 8 around the expansion portion 13.
A heating space 17 for accommodating the sub-stalk 5 is formed between the lid 6 and the lower mold die base 10, and a heater unit 20 for heating the sub-stalk 5 is arranged in the heating space 17. Has been done.

[Description of heater unit]
As shown in FIGS. 2 and 3, the heater unit 20 is made of metal (for example, made of stainless steel) through which the expansion portion 13 of the sub-stalk 5 penetrates, and has a plan-view square frame-shaped partition plate 21 and an upper surface of the partition plate 21. It is equipped with a plurality of rod-shaped infrared lamp heaters 22, 22 ... To be installed. In the partition plate 21 here, the width of one side 21A, 21A parallel to each other is larger than the width of the other side 21B, 21B, and the partition plate 21 has a rectangular shape in a plan view.
First, the partition plate 21 is arranged below the upper plate 23 and the lower plate 24 having a square frame shape in a plan view, the heat insulating board 25 arranged between the upper plate 23 and the lower plate 24, and the lower plate 24. It has a support base 26. As shown in FIG. 4, folded pieces 27, 27 ... Are formed on each side of the outer edge and the inner edge of the upper plate 23, and upward on each side of the outer edge of the lower plate 24. The folded pieces 28, 28 ... Are formed. In the assembled state of both plates 23 and 24 by screws or welding, the folded pieces 27 and 28 on the outer edge overlap each other, and the folded pieces 27 and 27 on the inner edge come into contact with the inner edge of the lower plate 24, respectively, so that the upper plate 23 A square frame-shaped space in a plan view in which the heat insulating board 25 is housed is formed between the lower plate 24 and the lower plate 24. The heat insulating board 25 is housed throughout the space.

The support base 26 has a square tubular shape having an opening area slightly larger than the inner opening surrounded by the inner edge of the lower plate 24, and the upper end thereof is joined to the lower surface of the lower plate 24.
The outer shape of the partition plate 21 is one size smaller than the through hole 16 of the lower mold die base 10. Therefore, as shown in FIG. 1, the partition plate 21 is below the through hole 16 of the lower mold die base 10 when the lower end of the support base 26 is installed on the upper surface of the lid 6 in a state where the sub-stalk 5 penetrates. Located on the side, the heating space 17 is divided into an upper space 17A above the upper plate 23 and a lower space 17B below the lower plate 24.

Then, as shown in FIGS. 5 and 6, the infrared lamp heater 22 includes a pair of carbon heaters 31 and 31 in an elongated cylindrical transparent glass outer tube 30 in which both ends in the longitudinal direction are closed. ..
The outer pipe 30 has a horizontal straight line portion 32 that is supported laterally along the sides 21A and 21B of the partition plate 21, a bent portion 33 that curves downward from the horizontal straight line portion 32, and a bent portion 33 that curves downward from the bent portion 33. It is L-shaped with an extending lower straight line portion 34, and a sealing terminal portion 35 is provided at the lower end of the lower straight line portion 34.

The carbon heater 31 is formed by forming thin plate-shaped carbon fiber filaments 37 in which slits are alternately cut at both side edges in the longitudinal direction in an elongated cylindrical transparent glass inner tube 36 having a diameter smaller than that of the outer tube 30. It is sealed with an inert gas. Inner sealing terminal portions 39 and 39 from which lead wires 38 and 38 electrically connected to the carbon fiber filament 37 are drawn out are provided at both ends of the inner pipe 36, and the horizontal straight portion 32 of the outer pipe 30 is provided. On the closed end side, the lead wires 38, 38 are electrically connected to each other, and the carbon fiber filaments 37, 37 are connected in series. On the opposite end side, the lead wires 38 and 38 are drawn out to the sealing terminal portion 35 through the bent portion 33 and the downward straight portion 34.

The carbon heaters 31 and 31 are housed in parallel in the horizontal straight portion 32 of the outer pipe 30, but here, as shown in FIGS. 6 and 7, the upper plates 23 are formed on the respective sides 21A and 21B of the partition plate 21. The carbon fiber filaments 37, 37 are fixed in the horizontal straight line portion 32 so as to be in an obliquely upward posture toward the center side (sub-stalk 5 side) of the partition plate 21 at an angle of 45 °. Further, the outer carbon heater 31 is located on the upper side of the inner carbon heater 31, and the upper and lower positions are positioned in the horizontal straight portion 32 so that the inner and outer carbon fiber filaments 37 and 37 are linear in the cross section. It is shifted and fixed. Further, as shown in FIGS. 2 and 3, a reflective surface 40 coated with an infrared reflective paint is formed on the outer surface of the horizontal straight portion 32 in the region of the outer half of the carbon fiber filaments 37 and 37. There is.

The infrared lamp heater 22 formed in this way has two fixed covers 41 fixed to the corners of the upper plate 23 on the partition plate 21, two on the wide side 21A inside and outside, and one on the narrow side 21B. , 41 ... Supported by. That is, by inserting the outer pipe 30 across the insertion holes 42, 42 formed on the facing surfaces of the fixed cover 41, each horizontal straight portion 32 becomes the upper plate 23 on the upper plate 23. Supported in parallel. However, in the two infrared lamp heaters 22 and 22 on the side 21A, the outer infrared lamp heater 22 is located on the upper side of the inner infrared lamp heater 22 as in the carbon fiber filaments 37 and 37. The positions of the insertion holes 42 and 42 are shifted up and down.
Then, the lower straight portion 34 of each infrared lamp heater 22 penetrates the through holes 43, 43, ... Provided in the partition plate 21 and projects below the lower plate 24 on the outside of the support base 26 to form a sealing terminal portion. 35 is located below the lower plate 24.

In the heating space 17 in which the heater unit 20 is installed, the infrared lamp heaters 22 provided on the sides 21A and 21B of the partition plate 21 surround the sub-stalk 5 from the outside in the upper space 17A, and the carbon heaters 31 The irradiation surfaces 37a of the carbon fiber filaments 37 and 37 are oriented toward the inner expansion portion 13 side, respectively. A paint containing an infrared absorbing material is applied to the outer surface of the Substoke 5 here. Further, in the upper space 17A, each infrared lamp heater 22 is located below the lower mold 8 exposed by the through hole 16 provided in the lower mold die base 10.
On the other hand, in the lower space 17B, the sealing terminal portions 35 of each infrared lamp heater 22 are arranged outside the support base 26, respectively. The lead wires 38 and 38 of the carbon heaters 31 and 31 are each covered with a heat-resistant tube, led out from the sealing terminal portion 35, pass outside the support base 26, and pass through the support base 26 as shown in FIG. It is pulled out to the outside via a guide cylinder 44 fixed to the outer surface of the above and connected to a power supply unit (not shown).

[Operation description of low-pressure casting equipment]
In the low-pressure casting apparatus 1 configured as described above, at the time of casting, the lower mold 8 and the upper mold 9 are preheated and molded by a mold heater or the like, and then the molten metal holding furnace 2 is inserted from the pressurizing port 7. The molten metal is filled into the cavity 11 from the sprue 14 of the lower mold 8 via the stalk 4 and the sub stalk 5.
At the same time or after a lapse of a predetermined time, the infrared lamp heaters 22 are energized to heat the carbon fiber filaments 37 of the carbon heaters 31 at 1200 to 1400 ° C. Therefore, the sub-stalk 5 is heated from substantially the entire circumference by the radiant heat from the irradiation surface 37a of the carbon fiber filaments 37 arranged on the sides 21A and 21B of the partition plate 21, and the molten metal in the sub-stalk 5 and the sprue 14 is heated. Is prevented from solidifying. At this time, since the entire circumference of the expansion portion 13 and the lower surface of the lower mold 8 are exposed in the upper space 17A by the through hole 16 of the lower mold die base 10, the expansion portion 13 is heated evenly to the upper end. The molten metal in the sprue 14 is also effectively heated.

If the pressure applied to the molten metal holding furnace 2 is released after the molten metal has solidified in the cavity 11, the unsolidified molten metal returns to the inside of the molten metal holding furnace 2 via the stalk 4. At this time, since the molten metal in the sub-stalk 5 and the sprue 14 is not solidified by the heating of the infrared lamp heater 22, the molten metal returns to the molten metal holding furnace 2 via the stalk 4.
Even if the sub-stalk 5 is heated to a high temperature (about 500 ° C.) in the upper space 17A, the lower space 17B is partitioned by the partition plate 21 having the heat insulating board 25, so that the lower space 17B The temperature rise is suppressed. The heat-resistant temperature of molybdenum used for the sealing terminal portion 35 is 350 ° C., and if it exceeds this, the life is significantly shortened. However, since the temperature in the lower space 17B is 350 ° C. or less, the sealing terminal portion 35 Deterioration due to heat is prevented.

[Effects of Invention of Low Pressure Casting Equipment and Heater Unit]
As described above, in the low-pressure casting apparatus 1 and the heater unit 20 of the above-described embodiment, the heating means of the sub-stalk 5 is arranged in the heating space 17 formed around the sub-stalk 5 and has the carbon fiber filament 37 (heating body). Infrared light consisting of a horizontal straight line portion 32 (heating portion) and a sealing terminal portion 35 provided at the end of the horizontal straight line portion 32 and leading out a lead wire 38 (wiring) electrically connected to the carbon fiber filament 37. The lamp heater 22 is used, and the heating space 17 is divided into an upper space 17A and a lower space 17B by a metal partition plate 21 (partition member) having a heat insulating board 25 (heat insulating layer), and the infrared lamp heater 22 is a horizontal straight line. The horizontal straight line portion 32 is arranged in the upper space 17A and the sealing terminal portion 35 is arranged in the lower space 17B by bending between the portion 32 and the sealing terminal portion 35.

As a result, even if the infrared lamp heater 22 is used as the heating means of the sub-stalk 5, the temperature rise of the sealing terminal portion 35 and the lead wire 38 can be suppressed and the durability can be ensured. Further, since the lead wire 38 is led out to the lower space 17B, the maneuverability is also good.
Further, due to the radiation effect of infrared rays, the sub-stalk 5 can be heated without heating the entire atmosphere of the heating space 17. Further, by adopting the infrared lamp heater 22, temperature control can be automated, and the man-hours for ignition and thermal power adjustment can be reduced as in the case of a gas burner, leading to improvement in workability and avoiding a temperature drop due to misfire. In addition, since it is not necessary to constantly energize the infrared lamp heater 22, energy consumption can be saved.

In particular, here, the infrared lamp heater 22 is arranged as an L-shaped bent rod-shaped body, the horizontal straight line portion 32 is arranged sideways in the upper space 17A, and the sealing terminal portion 35 is arranged downward in the lower space 17B. Therefore, the sealing terminal portion 35 can be reliably retracted into the lower space 17B while the sub-stalk 5 is effectively heated by the horizontal straight portion 32.
Further, the horizontal straight portion 32 of the infrared lamp heater 22 is the opposite of the sub-stalk 5 sandwiching the carbon fiber filament 37, assuming that the thin plate-shaped carbon fiber filament 37 serving as a heating element is enclosed in the outer tube 30 (glass tube). On the side, since the reflective surface 40 in which the infrared reflective paint is applied is formed on the outer surface of the outer tube 30, infrared rays that are easily absorbed by the sub-stalk 5 can be effectively emitted. Furthermore, since the reflective paint does not oxidize even at high temperatures, it is possible to prevent infrared rays from leaking, and improvement in heating efficiency can be expected.
Since the carbon fiber filament 37 is arranged in the outer tube 30 in a posture in which the irradiation surface 37a on the sub-stalk 5 side faces diagonally upward, the upper or lower part of the sub-stalk 5 having a distance from the infrared lamp heater 22 is provided. The mold 8 is also irradiated with infrared rays and can be heated uniformly. Therefore, the quality of the cast product is stable.

On the other hand, since the outer surface of the sub-stalk 5 is coated with an infrared absorbing material, the infrared absorbing rate of the sub-stalk 5 is increased, which leads to an improvement in heating efficiency.
Further, since the through hole of the sub-stalk 5 in the lower mold die base 10 is formed larger than the outer shape of the sub-stalk 5 to expose the lower mold 8 in the upper space 17A, the upper portion of the sub-stalk 5 and the sub-stalk 5 are exposed. The lower mold 8 is easily irradiated with infrared rays, and the lower mold 8 can be effectively heated. In addition, since the upper space 17A can be secured widely, the layout of the infrared lamp heater 22 is not restricted and the installation can be easily performed.
Further, since the partition plate 21 has a frame shape surrounding the outside of the sub-stalk 5 and a plurality of infrared lamp heaters 22 are supported by the partition plate 21 along the frame shape, the sub-stalk 5 is uniformly distributed from substantially the entire circumference. It can be heated.

[Explanation of change example]
In the above embodiment, an infrared lamp heater having a sealing terminal portion at one end of the heat generating portion is used, but an infrared lamp heater having sealing terminal portions at both ends of the heat generating portion can also be used. In this case, the sealing terminals at both ends project into the lower space in a U-shape with both ends bent instead of an L-shape. The support structure of the infrared lamp heater is not limited to the above form, and a support plate or the like fixed on the partition plate may be used.
The infrared lamp heater has a form in which a pair of carbon heaters are housed, but it may be formed by only one carbon heater. In this case, the inner tube is omitted and one carbon fiber filament is enclosed. One infrared lamp heater may be arranged on each side.
The shape of the carbon fiber filament is not limited to the above-mentioned form, and a carbon fiber filament having no slit may be used. As the heating element, not only a carbon heating element but also a tungsten heating element can be adopted.
The tilting posture of the heating element with respect to the sub-stalk is not limited to 45 °, but can be appropriately changed in the range of about 30 to 60 °. However, if the required amount of heat is obtained, the posture may be horizontal or vertical instead of the tilted posture, or may be combined with the tilted posture.

On the other hand, in the above embodiment, a reflection surface is formed on the outer tube, but instead, as shown in FIG. 8, a metal reflection having a semicircular or arcuate cross section inside the outer tube 30. A plate 45 may be provided. In this case as well, infrared rays can be effectively emitted. Further, since the reflector 45 does not oxidize even at a high temperature, it is possible to prevent infrared rays from leaking, and improvement in heating efficiency can be expected. However, the reflective surface and the reflector may be omitted, and the infrared absorbing paint of Substoke may also be omitted.
In the above embodiment, the partition member also has a quadrangular partition plate in a plan view, but may have another shape such as a triangle, a polygon, or a circle in a plan view as long as it has a shape surrounding the outer circumference of the sub-stalk. On the contrary, the partition member is not limited to the frame shape, and may be a partition member having a U-shape or a C-shape in a plan view, or a plurality of these partition members may be arranged around the sub-stalk. In this case, the number and arrangement of the infrared lamp heaters may be changed according to the form of the partition member.

The heat insulating layer of the partition member is not limited to the heat insulating board of the above-mentioned form, and can be formed by laminating a plurality of heat insulating sheets or filling with heat-resistant glass long fibers.
In the above embodiment, the heating space is divided into upper and lower parts by a horizontal partition plate located below the through hole to make the lower space semi-closed, but depending on the shape of the sub-stalk or the partition member, the partition member is penetrated. The lower space may be closed by fitting it into the hole or by providing a wall body surrounding the lower space on the outer periphery of the partition member. Similarly, for example, even if a partition member having an inverted U-shaped or inverted U-shaped cross section is arranged in the heating space and the sealing terminal portion is arranged in the lower space closed inside the partition member, the temperature is increased. It is possible to suppress the rise.

1 ... Low pressure casting equipment, 2 ... Molten holding furnace, 3 ... Mold, 4 ... Stoke, 5 ... Substoke, 6 ... Lid, 8 ... Lower mold, 9 ... Upper mold 10, ・ ・ Lower mold die base, 11 ・ ・ Cavity, 12 ・ ・ Cylindrical part, 13 ・ ・ Expansion part, 14 ・ ・ Gate, 16 ・ ・ Through hole, 17 ・ ・ Heating space, 17A ・ ・ Upper space, 17B ... Lower space, 20 ... Heater unit, 21 ... Partition plate, 22 ... Infrared lamp heater, 23 ... Upper plate, 24 ... Lower plate, 25 ... Insulation board, 26 ... Support stand, 30 ... outer tube, 31 ... carbon heater, 32 ... horizontal straight part, 33 ... bent part, 35 ... sealing terminal part, 36 ... inner tube, 37 ... carbon fiber filament, 37a ... Irradiated surface, 38 ... lead wire, 40 ... reflective surface, 45 ... reflective plate.

Claims (8)

1. With a molten metal holding furnace,
   The stalk inserted in the molten metal holding furnace and
   A mold arranged above the stalk and composed of an upper mold and a lower mold,
   A sub-stalk disposed between the stalk and the lower mold,
   A low-pressure casting apparatus including a heating means for heating the sub-stalk.
   The heating means is arranged in a heating space formed around the sub-stalk, and has a heating element having a heating element and a lead wire provided at an end of the heating element and electrically connected to the heating element. It is an infrared lamp heater consisting of a sealing terminal to be derived.
   The heating space is divided into an upper space and a lower space by a metal partition member having a heat insulating layer.
   The infrared lamp heater is bent between the heat generating portion and the sealing terminal portion, and the heat generating portion is arranged in the upper space and the sealing terminal portion is arranged in the lower space. A low-pressure casting machine characterized by.
2. The infrared lamp heater is a rod-shaped body bent in an L shape, and the heat generating portion is arranged sideways in the upper space, and the sealing terminal portion is arranged downward in the lower space. The low-pressure casting apparatus according to claim 1.
3. The heat generating portion of the infrared lamp heater is formed by enclosing a thin plate-shaped carbon fiber filament serving as a heating element in a glass tube, and on the opposite side of the sub-stalk sandwiching the carbon fiber filament, the outer surface of the glass tube is formed. The low-pressure casting apparatus according to claim 1 or 2, wherein an infrared reflective paint is applied to the surface of the casting medium, or a metal reflecting plate is arranged.
4. The low-pressure casting apparatus according to claim 3, wherein the carbon fiber filament is arranged in the glass tube in a posture in which the irradiation surface on the sub-stalk side faces diagonally upward.
5. The low-pressure casting apparatus according to any one of claims 1 to 4, wherein an infrared absorbing material is applied to the outer surface of the sub-stalk.
6. A lower mold die base that supports the lower mold and through which the sub-stalk penetrates is provided, and the through hole of the sub-stalk in the lower mold die base is formed to be larger than the outer shape of the sub-stalk, and the lower mold is formed. The low-pressure casting apparatus according to any one of claims 1 to 5, wherein the mold is exposed in the upper space.
7. The partition member has a circular shape surrounding the outside of the sub-stalk, and a plurality of the infrared lamp heaters are supported by the partition member along the circular shape. The low pressure casting apparatus according to any one.
8. Between the molten metal holding furnace, the stalk inserted in the molten metal holding furnace, the mold disposed above the stalk and composed of the upper mold and the lower mold, and the stalk and the lower mold. A heater unit for heating the substalk, which is provided in a low-pressure casting apparatus including the substalk arranged in the above.
   A metal partition member arranged in a heating space formed around the sub-stalk, having a heat insulating layer, and partitioning the heating space into an upper space and a lower space.
   It has an infrared lamp heater including a heat generating portion having a heating element and a sealing terminal portion provided at an end of the heating element and leading out a lead wire electrically connected to the heating element.
   The infrared lamp heater is bent between the heat generating portion and the sealing terminal portion, and the heat generating portion is supported on the upper side of the partition member and the sealing terminal portion is supported on the lower side of the partition member. A heater unit for low-pressure casting equipment, which is characterized by being used.

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