JP4102132B2 - Mold casting equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a mold casting apparatus capable of controlling the cooling rate of a molten metal poured into a casting space of a mold.
[0002]
[Prior art]
As a mold casting apparatus for controlling the cooling rate of the molten metal, an apparatus described in Japanese Patent Laid-Open No. 62-64451 is known. This mold casting apparatus divides the inside of the mold, that is, the thick part into a cooling chamber, a flat greenhouse, and a greenhouse, and uses a combination of two or more of these chambers to reduce the cooling rate of the mold. A fast part and a slow part are formed, and the temperature of each part of the poured molten metal is appropriately controlled. By using such a mold casting apparatus, it is possible to ensure the heat retaining property of the mold at the position where it is desired to avoid the temperature of the injected molten metal from falling without making the apparatus large and complicated. Quality can be improved. Further, as a mold casting apparatus that partially delays the cooling rate of the molten metal, as described in JP-A-7-185738, a lower mold having an air layer as a heat retaining part, There has also been proposed a structure in which a gap having a heat insulating function is provided between an inner cylinder and an outer cylinder of an upper mold as described in JP-A-9-277015.
[0003]
[Problems to be solved by the invention]
However, such a mold casting apparatus accurately sets the local temperature characteristics of the side (inner surface) of the casting space of the mold, which is in direct contact with metal melting and has the closest relationship to the temperature change of the molten metal. However, the inner surface of the mold itself is integrally formed of the same material over a wide range or a long range as compared with the temperature adjustment portion, so that the temperature control or the heat retention control is roughly performed. In other words, it is difficult to ensure spot temperature control, that is, local temperature control or heat retention control that is precisely limited to a predetermined mold position. There is a possibility that the directional solidification of the mode that can be obtained cannot be achieved.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a mold casting apparatus that is capable of precise temperature control or heat retention control while having a simple structure.
[0005]
[Means for Solving the Problems]
In order to achieve this object, the mold casting apparatus of the present invention is provided with a temperature adjusting unit at a required position of the mold, and the molten metal injected into the casting space formed in the mold is formed by the temperature adjusting unit. A mold casting apparatus that cools and solidifies while controlling heat retention, wherein the temperature adjusting unit opens an opening of a temperature adjusting recess provided in the mold so as to open into the casting space. It is configured to be closed by a closing member to be formed. The mold casting apparatus of the present invention has only such a temperature adjusting part (having a heat retaining function or a heat insulating function) having such a structure, or has another structure, for example, a temperature adjusting part formed from the outer surface side of the mold. Or it is comprised so that it may also have a heat insulation part. The casting space is composed of, for example, a product casting space (cavity) and a runner system (hot water structure). In many cases, the temperature adjusting portion of the present invention is formed in accordance with a casting method after forming a mold or according to a change in the casting method. The forming method is to form a temperature adjusting recess or a heat retaining recess having an appropriate depth on the inner surface of the mold at the temperature adjusting position or the heat retaining position, and to close the temperature adjusting recess so as to be sealed and closed. A member (often a closure plate) is joined to the inner surface of the mold. Joining is performed by welding, for example, but the heat of the closing member is difficult to escape to the surrounding mold part. Therefore, the molten metal is appropriately kept warm at the position of the closing member, and the cooling rate becomes slow. For example, a material having a lower thermal conductivity than the surrounding mold material is used for the closing member, but the same material as the surrounding mold material may be used. The size or width of the temperature adjustment recess is appropriately set, for example, to exactly match the portion to be temperature adjusted. Even when the temperature control part is formed when changing the casting method, the inner surface of the mold can be easily formed because there are no processing obstructions such as a mold support member attached to the outer surface, and it can be formed directly on the inner surface. Since the concave portion for temperature adjustment is formed, the formation position becomes accurate. For joining of the blocking member, other joining means other than welding may be used as long as reliable sealing performance can be secured in a high temperature state at the time of pouring the molten metal. The mold casting apparatus of the present invention is intended for those used for gravity casting, pressure casting, differential pressure casting, and the like, and is not particularly limited to those used for a specific casting method.
[0006]
In order to ensure a sufficient heat-retaining function or an appropriate heat-retaining state, the temperature adjustment part forms the opening of the temperature adjustment recess provided in the mold so as to open into the casting space, and forms the inner surface of the mold. It is preferable that a vacancy is formed by closing with a closing member. The vacant chamber is filled with a gas that has a heat insulation function, but its thermal conductivity is extremely small, so air that effectively blocks heat transfer from metal melting to the outer surface of the mold is sealed and the vacant chamber is filled with the air chamber. By configuring as above, effective heat retention control can be achieved with a simple structure. When providing a vacant space in the temperature adjustment section, for example, a material having a higher thermal conductivity than the mold material is used for the closing member, and this closing member is formed as thin as possible within a range having the required strength on the inner surface of the mold. Thus, it is possible to prevent a large amount of heat from being transferred from the metal melt at the heat retaining position to the outer surface side of the mold through the closing member and the mold portion around the closing member.
[0007]
In many cases, the temperature adjusting unit is configured as a hot-water supply forming unit (a hot-water supply unit) of the runway system. In particular, when the weir is formed to be considerably narrow or small for easy folding, it is effective to configure the temperature adjusting portion in the weir portion or the vicinity of the weir. Since the hot water maintains the fluidity by the heat retaining function of the temperature adjusting unit, it is not necessary to increase the hot water volume in order to obtain a large amount of heat for ensuring the fluidity, and therefore the product yield can be improved. Further, if the volume of the feeder is small, the solidification rate of the feeder after losing the feeder effect is fast, and therefore the cycle time can be shortened by early mold opening. By the way, if the temperature adjustment part is formed so as to extend to the runner weir, the nest generated by the slow initial cooling rate of the feeder may reach the product part. It is effective to terminate the temperature adjusting unit immediately before the weir and form a nest growing unit between the tip position of the temperature adjusting unit and the weir.
[0008]
The temperature adjustment part is often formed in the product casting space. Normally, the product thin-walled part that needs to be slowed in the cooling rate is kept in a spot or only a predetermined part, but in order to ensure overall directional solidification. In some cases, it is formed to extend long along the flow path of the metal melt. The flow path of the molten metal can be easily determined by arranging temperature sensors such as thermocouples at various locations of the mold and measuring the temperature change when the molten metal is injected.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows a mold casting apparatus according to the present invention for casting an aluminum alloy product, and shows a main part of a temperature control unit in a runner system, and FIG. 2 shows a structure of the temperature control unit. FIG.
[0011]
The mold casting apparatus 1 has an upper mold 3 that can be moved up and down, a lower mold 5 that is fixed on a base (not shown), and a horizontal mold 7 that can move in the horizontal direction (radial direction). 3, an aluminum alloy product cavity 9, which is a casting space, is formed between the lower mold 5 and the horizontal mold 7. A runner system which is a casting space is formed between the lower mold 5 and the lower mold 5 and the horizontal mold 7 so as to be continuous with the cavity 9. The molten aluminum alloy (metal melt) It is supplied from the gate 11, passes through the runner 13, and is filled in the cavity 9. The upper side of the upper mold 3 is attached to the vertical or elevating drive device 15, and the side surface of the horizontal mold 7 is fixed to the side drive device 17.
[0012]
On both sides of the forming surface 21 of the feeder part 19 provided in the runner 13, the temperature adjusting recesses 25 and 27 having a depth of 10 mm extend from the gate 11 side to the weir 23 side, respectively. Opening to the hot water part 19 is formed from the hot water part 19 side or the forming surface 21 side, and the openings of the temperature adjusting recesses 25 and 27 are respectively 5 mm thick closing plates 29 and 31 (closing members). The temperature adjusting part having a spot-like heat-retaining function is formed in which air chambers 33 and 35 having a width of 5 mm are formed between the temperature adjusting recesses 25 and 27 and the closing plates 29 and 31. Is configured. The closing plates 29 and 31 form the inner surface or forming surface of the feeder 19. The closing plates 29 and 31 can be made of the same material as that of the main body 37 (a portion around the closing plates 29 and 31). For example, a ductile material, an SKD material, or an FC material can be used. The materials of the closing plates 29 and 31 and the surrounding body 37 are different, such as using an aluminum alloy for the body 37 around the closing plates 29 and 31 and using an SKD material for the closing plates 29 and 31. Can do. Alternatively, a material having a lower thermal conductivity than the main body 37 can be used for the closing plates 29 and 31. Normally, the space width of the feeder 19 of the runner 13 having such a shape is designed to be about 40 mm in order to increase the feeder volume, but here, the space between the closing plates 29 and 31, that is, the feeder The space width of 19 was designed to be 20 mm, and the casting weight of the molten aluminum alloy was reduced by 1 kg. Despite such a significant decrease in the volume of the hot metal, the molten aluminum alloy in the hot water portion 19 (including the weir 23) of the runway 13 is maintained until the molten aluminum alloy in the cavity 9 is sufficiently solidified. Did not lose the liquidity required. That is, since the closing plates 29 and 31 are separate from the surrounding main body 37, as shown in FIG. B (non-joined part) is formed, and heat hardly escapes from the closing plates 29 and 31 to the main body 37, and the heat retaining property of the molten aluminum alloy is ensured at the positions of the closing plates 29 and 31. In addition, you may form an air chamber or a temperature control part only in one side instead of the both sides of the formation surface 21 of the feeder part 19.
[0013]
The tips of the temperature adjusting recesses 25 and 27 extend from the weir 23 to 15 mm before, and a 15 mm long section between the weir 23 and the air chambers 33 and 35 transmits the nest to the aluminum alloy in the cavity 9. It functions as a growth part 39 that is not allowed to be removed. In order to make the function of the nest growing part 39 sufficient, it is necessary to increase the volume of the nest growing part 39. Therefore, as shown in FIG. The portion 41 may be formed.
[0014]
FIG. 5 is a view showing a case where a temperature adjusting unit is also formed at the cavity 9 position.
[0015]
For example, the cavity forming surface 43 of the horizontal mold 7 surrounds the annular thin portion casting space 45 of the cavity 9 and is opened from the cavity 9 side or the cavity forming surface 43 side so as to open to the cavity forming surface 43 or the cavity 9. A plurality of adjustment recesses 47 are formed at equal intervals in the circumferential direction, and each of the temperature adjustment recesses 47 has a spot-like heat retaining function by forming an air chamber 51 with the opening closed by a closing plate 49. Functions as a temperature adjustment unit. The closing plate 49 forms the inner surface or forming surface of the cavity 9. The closing plate 49 can be made of the same material as that of the main body 37 (a portion around the closing plate 49). For example, a ductile material, an SKD material, or an FC material can be used. The material of the closing plate 49 and the surrounding body 37 can be different, such as using an aluminum alloy for the surrounding body 37 and using an SKD material for the closing plate 49. Alternatively, a material having lower thermal conductivity than the main body 37 can be used for the closing plate 49.
[0016]
【The invention's effect】
As described above, if the mold casting apparatus of the present invention is used, the cooling rate of the poured molten metal can be accurately limited and controlled at a required position.
[Brief description of the drawings]
FIG. 1 is a view showing a main part of a mold casting apparatus of the present invention for casting an aluminum alloy product, in which a temperature adjusting unit is configured in a runner system.
FIG. 2 is a schematic cross-sectional view for illustrating a structure of a temperature adjustment unit.
FIG. 3 is a view showing a welded state of a closing member.
FIG. 4 is a schematic cross-sectional view for illustrating another structure of a runner system.
FIG. 5 is a diagram showing a case where a temperature adjustment unit is also formed at a cavity position.
[Explanation of symbols]
1 Mold casting apparatus 25, 27, 47 Recesses for temperature adjustment 29, 31, 49 Closure plate (closure member)
33, 35, 51 Air chamber (vacant)

Claims (5)

A mold casting apparatus that is provided with a temperature adjustment unit at a required position of the mold, and cools and solidifies the molten metal injected into the casting space formed in the mold while maintaining the temperature in the temperature adjustment unit,
The temperature adjustment unit, the opening of the temperature adjustment recess provided in the runner of the mold so as to open into the casting space, and closed by closing member will form the inner surface of the mold air A chamber,
In the runner of the mold, an bulge portion for increasing the volume of the runner is formed at the end of the weir connected to the cavity,
The mold casting apparatus, wherein the temperature adjusting recess is provided on the opposite side of the bulging portion and adjacent to the bulging portion . 2. The mold casting apparatus according to claim 1, wherein the closing member has a thermal conductivity smaller than that of a surrounding mold material. 3. The mold casting apparatus according to claim 1, wherein the closing member is formed thin. 4. The mold casting apparatus according to claim 1, wherein the closing member is joined to an opening edge of the temperature adjusting recess by welding. 5. The mold casting apparatus according to claim 1, wherein the temperature adjusting unit is formed after the mold is formed. 6.

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