JP2015193031A - Casting apparatus and casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a cast product by performing the pressurized replenishment of the molten metal of an amount corresponding to the coagulated shrunk volume in a cavity without defect.SOLUTION: A casting apparatus comprises: a mold forming a cavity having an opening down below; a pressurization chamber which is disposed near the mold, houses a molten metal and feeds the molten metal into the cavity from below the opening through a stalk; a gate seal pin which is disposed in a freely advancing and retreating way with respect to the opening and opens or closes the opening; and a pressurization pin which communicates with the cavity, is disposed in the freely advancing and retreating way in a direction crossing with the advancing/retreating direction of the gate seal pin with respect to a basin part formed above the opening, and pressurizes the molten metal filled in the basin part.

Description

  The present invention relates to a casting apparatus and a casting method for manufacturing a product by filling a metal mold with molten metal.

  2. Description of the Related Art Conventionally, a vertical casting apparatus for manufacturing aluminum composite products such as an aluminum wheel and an engine block by a low pressure casting method or a low intermediate pressure casting method is known (for example, see Patent Document 1 below). This vertical casting apparatus is composed of a lower mold (fixed mold) and an upper mold (movable mold) that form a cavity, and a molten metal is poured into the cavity from below through a casting stalk (hot water supply pipe) and filled. Casting means having a pressurized pouring pot (pressurizing chamber, crucible) having a capacity capable of accommodating a required amount of molten metal that can be detached once, and a molten metal inlet gate (pouring gate) communicating with cast stalk formed in the fixed mold ) And closing means for closing the gate.

  The casting means includes a pressurized gas introducing means having a gas cylinder and a piston for introducing a pressurized gas into the pressurized hot pot, and controls the filling speed of the molten metal into the cavity by controlling the piston speed. Specifically, when casting, the gas pressure is applied to the molten metal surface of the pressurized pouring pan to fill the cavity with the molten metal through the casting stalk, and then the closing pin of the gate is advanced (lowered) to move the gate. After closing, the pressure plunger (pressurizing means) is immediately advanced by the hydraulic cylinder, so that the molten metal for the solidification shrinkage volume in the cavity is pressurized and supplied from the hub hot water reservoir (cavity first hot water reservoir). Is done.

JP 2007-253168 A

  In the vertical casting apparatus of the prior art disclosed in the above-mentioned Patent Document 1, since the filling of the molten metal into the cavity and the replenishment of the molten metal into the first hot water reservoir are performed in parallel, the molten metal flows into the cavity. It takes time until the molten metal in the cavity is pressurized by the pressurizing means after starting to do so.

  In the meantime, the molten metal already filled in the cavity cools down, and the pressure applied by the pressurizing means is not sufficiently transmitted, making it difficult to crush the shrinkage nest, and the hot water around the end of the product due to the drop in hot water temperature. There is a problem that the appearance deteriorates and the appearance defect tends to occur. In addition, although there is a gas discharge gap (gap) around the cavity 1st hot water reservoir, if the gas escapes worse due to the insertion of a release agent etc., the air will stay and the casting shrinks. It is difficult to fill and secure the molten metal corresponding to (solidification shrinkage), and there is a possibility that the insertion of the molten metal may become an obstacle to the sliding of the pressurizing means.

  The present invention provides a casting apparatus and a casting method capable of solving the above-described problems caused by the prior art and improving the quality of a cast product by performing pressurized replenishment of molten metal for the solidification shrinkage volume in the cavity without any trouble. For the purpose.

  The casting apparatus according to the present invention includes a mold that forms a cavity having an opening below, and a molten metal that is disposed in the vicinity of the mold and that supplies molten metal into the cavity through stalk from below the opening. The gate seal pin is advanced and retracted with respect to a pressurizing chamber, a gate seal pin that is arranged to be movable forward and backward with respect to the opening, and communicates with the cavity and is formed above the opening. And a pressurizing pin that pressurizes the molten metal that is disposed so as to freely advance and retreat in a direction that intersects the direction and that is filled in the hot water pool.

  In one embodiment of the present invention, a pressurizing unit that supplies gas to the sealed space of the pressurizing chamber to pressurize the pressurizing chamber, and a depressurizing unit that discharges the gas from the cavity and decompresses the inside of the cavity. And further comprising.

  In another embodiment of the present invention, the mold is a horizontal mold in which a movable mold provided on the movable plate is opened and closed in a horizontal direction with respect to the fixed mold provided on the fixed platen.

  The casting method according to the present invention includes a mold that forms a cavity having an opening below, and a molten metal that is disposed in the vicinity of the mold and supplies the molten metal into the cavity through stalk from below the opening. The gate seal pin is advanced and retracted with respect to a pressurizing chamber, a gate seal pin that is arranged to be movable forward and backward with respect to the opening, and communicates with the cavity and is formed above the opening. A casting method using a casting apparatus that includes a pressurizing pin that pressurizes a molten metal that is disposed so as to be able to advance and retreat in a direction that intersects a direction, and that is filled in the puddle, wherein the molten metal is passed from the pressurizing chamber through the stalk and the opening. A step of filling the puddle, a step of continuously filling the cavity with the molten metal filled in the puddle, and advancing the gate seal pin It was characterized by comprising a step of pressure supplied to the a step of closing the opening, the melt molten metal into the cavity in the reservoir by advancing the pressurizing pin after closing the opening.

  In one embodiment of the present invention, in the pressurizing and replenishing step, the molten metal corresponding to the solidification shrinkage volume in the cavity is replenished from the hot water pool.

  According to the present invention, it is possible to improve the quality of a cast product by performing pressure replenishment of molten metal for the solidification shrinkage volume in the cavity without any trouble.

It is a schematic sectional drawing which shows the casting apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process. It is sectional drawing which shows a part of the casting apparatus in order of a casting process.

  Hereinafter, a casting apparatus and a casting method according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic sectional view showing a casting apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, a casting apparatus 100 according to an embodiment of the present invention is adjacent to a holding chamber 11 that holds a molten metal 1 and communicated with the holding chamber 11 via a hole 12a. A container 102 that forms a pressurizing chamber (crucible) 10 that accommodates and pressurizes the molten metal 1 supplied from the holding chamber 11 is provided in the vicinity of the mold part 101.

  In the pressurizing chamber 10 and the holding chamber 11, for example, the molten metal 1 stored therein is heated to a temperature necessary for maintaining the molten state of the molten metal 1 (for example, a temperature of about 500 ° C. to 700 ° C.). For this purpose, a heater (not shown) is installed. Further, the holding chamber 11 is provided with a stopper 12 that fits into a hole 12a for controlling the supply of the molten metal 1 to the pressurizing chamber 10.

  The stopper 12 is driven based on the control of a control device (not shown) so that a constant amount of the molten metal 1 is always accommodated in the pressurizing chamber 10 in the initial state of the casting process by the casting apparatus 100, for example. As the stopper cylinder 12b and stopper pin 12c move forward and backward, the hole 12a is opened and closed. Note that the volume of the holding chamber 11 in the container 102 is configured to be larger than the other parts of the container 102.

  The upper end openings of the pressurizing chamber 10 and the holding chamber 11 are closed by the fixing plate 13, and the upper surface space of the molten metal 1 in the pressurizing chamber 10 is a sealed space. The fixing plate 13 on the holding chamber 11 is provided with a supply port 13 b for supplying the molten metal 1 into the holding chamber 11. A gas supply path 14 communicates with the fixed plate 13 on the pressurizing chamber 10.

  The gas supply path 14 is connected to a gas supply unit (not shown), for example, supplies an inert gas into the pressurizing chamber 10 to gas-pressurize the molten metal 1 in the pressurizing chamber 10 and lowers the hot water surface in the stalk 17. It is provided to release the atmosphere to make it happen. In addition, on the fixed plate 13 on the pressurizing chamber 10, a hot water level detection rod 16 extending toward the hot water surface of the molten metal 1 in the pressurizing chamber 10 is installed. When the molten metal 1 is sent from the holding chamber 11 to the pressurizing chamber 10 through the hole 12a, the molten metal level detecting rod 16 indicates whether or not the molten metal level of the molten metal 1 in the pressurizing chamber 10 has reached a predetermined level. Detect.

  On the other hand, the mold part 101 includes a plate-like fixed plate 20 arranged in parallel so as to face the horizontal direction, and a movable plate 30 that moves forward and backward (moves back and forth) with respect to the fixed plate 20 in the horizontal direction. It has been. A fixed mold 21 is mounted on the surface 20 a facing the movable plate 30 of the fixed plate 20. In addition, a movable mold 31 that is closed and opened in the horizontal direction with respect to the fixed mold 21 is mounted on the side of the movable plate 30 facing the fixed plate 20.

  The fixed die 21 is mounted with a substantially rod-shaped gate seal pin 22 arranged so that the axial direction is a vertical direction. Further, below the fixed mold 21, a hot water outlet 17 a having one end opened is formed, and the upper end of a cylindrical stalk 17 communicating with the pressurizing chamber 10 is connected and fixed. In the vicinity of the upper end of the stalk 17, a gas introduction path 28 for introducing an inert gas into the hot water outlet 17a is provided.

  A portion of the fixed mold 21 where the upper end of the stalk 17 is connected and fixed opens to the movable mold 31 side, and forms a puddle 23 together with a pressure sleeve 33 of the movable mold 31 described later. 24. A hot water tap 25 that is an opening is formed between the hot water reservoir 23 and the hot water outlet 17 a of the stalk 17 in the hot water reservoir forming portion 24.

  A piston cylinder 26 is provided on the upper end side of the fixed plate 20 to move the gate seal pin 22 in the vertical direction so as to be movable back and forth with respect to the gate 25. The gate seal pin 22 is driven by the piston cylinder 26 to open and close the gate 25. In addition, the lower side surface of the fixed plate 20 has a rod 27a penetrating the fixed plate 20 and the hot water pool forming portion 24, and a piston mechanism 27 for removing the hot water pool remaining in the hot water pool forming portion 24 after casting. Is provided.

  The movable mold 31 is provided with a movable plate 30 and a pressure rod 32a penetrating the movable mold 31 so that the axial direction is a horizontal direction. A substantially cylindrical pressure pin 32 is mounted on the distal end side of the pressure rod 32 a while being accommodated in a pressure sleeve 33 provided in the movable mold 31 and extending in the horizontal direction. The pressurizing sleeve 33 forms a puddle 23 by contacting the peripheral edge of the opening of the puddle forming portion 24 when the tip portion thereof is closed.

  A pressure cylinder 34 is provided on the side surface of the movable plate 30 to move the pressure pin 32 in the horizontal direction so that the pressure pin 32 can move forward and backward in the pressure sleeve 33. The pressurizing pin 32 is driven by the pressurizing cylinder 34 and moves forward and backward between a forward limit reaching the distal end within the pressure sleeve 33 and a backward limit of a predetermined position.

  The fixed mold 21 and the movable mold 31 form a cavity 40 when the mold is closed, and also form a runner 41 that communicates the lower end portion of the cavity 40 and the hot water pool 23 in the hot water pool forming section 24. . A gas discharge path (not shown) is provided on the mating surface of the fixed mold 21 and the movable mold 31, and this gas discharge path is connected to a gas discharge section (not shown). Thereby, gas is discharged from the cavity 40 by, for example, low vacuum suction during casting, and the inside of the cavity 40 is decompressed.

  In the casting apparatus 100 configured as described above, an inert gas is supplied from the gas supply unit into the pressurizing chamber 10 through the gas supply path 14 during casting, and the gas pressure is applied to the molten metal surface of the molten metal 1 in the pressurizing chamber 10. The hot water reservoir 23 is filled with the molten metal 1 through the hot water outlet 17a and the hot water port 25 of the stalk 17.

  The gas pressure is continuously applied as it is, and the molten metal 1 is filled into the cavity 40 from the hot water reservoir 23 through the runner 41, and the gate seal pin 22 is moved forward to close the gate 25. Immediately after closing the pouring gate 25, the pressure pin 32 is moved forward to the advance limit of the pressure sleeve 33 to pressurize the molten metal 1 in the hot water reservoir 23, and the molten metal 1 corresponding to the solidification shrinkage volume in the cavity 40 is heated. Replenish into cavity 40 through way 41.

  Thereby, compared with the conventional vertical casting apparatus, time until the molten metal 1 previously filled in the cavity 40 is pressurized by the pressure pin 32 can be shortened, and the molten metal 1 in the cavity 40 can be reduced. Can be effectively applied. Further, since the hot water supply 23 is filled with the molten metal 1 and then the molten metal is filled in the cavity 40, the pressure supply is performed. Therefore, it is possible to improve the quality of the cast product by supplying the molten metal under pressure without problems.

  Further, when casting a casting product in which the volume in the cavity 40 increases or decreases, according to the casting apparatus 100 according to the present embodiment, the gas does not stay in the puddle 23, and the puddle forming portion 24 and the pressurizing sleeve. Without changing the vertical size of 33, the horizontal size can be changed to appropriately change the volume of the sump 23.

  That is, when the pressure pin and the gate seal pin are arranged concentrically as in the conventional vertical casting apparatus, increasing the diameter of the pressure pin increases the distance between the cavity and the sump. Connected. For this reason, not only is the pressure applied to the molten metal by the pressure pin disadvantageous, but also the yield of the cast product is deteriorated, so that it is difficult to easily increase the diameter of the pressure pin.

  Further, when the height of the hot water pool is increased, a gas pool is formed, and the back pressure of the gas impedes the filling of the molten metal into the hot water pool, or the time for filling the molten metal into the cavity in parallel with this increases. Therefore, when pressurization with a pressurizing pin is performed, the temperature of the molten metal in the cavity is lowered, causing a problem.

  In this regard, the casting apparatus 100 according to the present embodiment has a pressure cylinder 34 and a pressure rod 32a so that the pressure pin 32 can be moved back and forth in the direction intersecting the forward and backward direction of the gate seal pin 22, that is, in the horizontal direction. The pressure pin 32 and the pressure sleeve 33 are arranged. As a result, it is possible to eliminate problems associated with insufficient casting pressure and insufficient amount of hot water, which are problems in the conventional vertical casting apparatus that closes the gate and pressurizes the molten metal only from the vertical direction.

  The mold unit 101 of the casting apparatus 100 described above has a so-called horizontal clamping method in which the movable mold 31 is closed and opened in the horizontal direction with respect to the fixed mold 21. A configuration of a vertical mold clamping method in which the mold is closed and opened in the vertical direction (vertical direction) with respect to the fixed mold 21 may be employed. Therefore, in the casting apparatus 100 according to the present embodiment, it is possible to increase the degree of freedom in designing the mold plan.

Next, a casting method in the casting apparatus 100 configured as described above will be described.
2 to 11 are sectional views showing a part of the casting apparatus 100 in the order of casting processes.
First, as shown in FIG. 2, before casting, the movable mold 31 and the stationary mold 21 are closed, a cavity 40 and a runner 41 are formed, and the pressure pin 32 is placed in the pressure sleeve 33. Make sure that you are in the retreat limit.

  Next, as shown in FIG. 3, the inside of the pressurizing chamber 10 is pressurized by supplying an inert gas from the gas supply section to the sealed space in the pressurizing chamber 10 through the gas supply path 14, and the gas discharge path The inside of the cavity 40 is depressurized by performing a low vacuum suction by the gas discharge unit via As a result, the molten metal 1 is filled into the hot water reservoir 23, the runner 41, and the cavity 40 through the hot water outlet 17 a and the hot water outlet 25 of the stalk 17.

  Next, as shown in FIG. 4, the gate seal pin 22 is advanced in the downward direction indicated by the arrow in the figure to close the gate 25. Then, as shown in FIG. 5, an inert gas is introduced from the gas introduction path 28 into the hot water outlet 17 a of the stalk 17, and the molten metal surface of the molten metal 1 in the stalk 17 is pressurized and lowered.

  Next, as shown in FIG. 6, the pressurizing pin 32 in the pressurizing sleeve 33 is moved through the pressurizing rod 32a in the right direction indicated by the arrow in FIG. The filled molten metal 1 is pressurized by the pressure pin 32 and supplied into the cavity 40 through the runner 41. At this time, the gas in the cavity 40 may be discharged.

  After that, as shown in FIG. 7, the pressure rod 32a is moved in the left direction indicated by the arrow in the drawing to move the pressure pin 32 in the pressure sleeve 33 to the retreat limit, and as shown in FIG. The seal pin 22 is retracted in the upward direction indicated by the arrow in the figure to open the gate 25. Then, as shown in FIG. 9, the movable mold 31 is moved in the left direction indicated by the arrow in the drawing to open the mold, and the rod 27 a is moved by the piston mechanism 27 to remain in the puddle formation portion 24. 24a is removed together with the cast product 49.

  Finally, as shown in FIG. 10, the cast product 49 is taken out from the cavity 40, and the stopper 12 of the holding chamber 11 is raised in the upward direction indicated by the arrow in the figure, and lowered after detection by the molten metal level detection rod 16. Then, after the molten metal 1 is returned to fill the outlet 17a, a cleaning spray process is performed, and the movable mold 31 is moved in the direction indicated by the arrow in the drawing to close the mold as shown in FIG. Proceed to the next casting process.

  According to the casting method of this embodiment, the gate seal pin 22 and the pressure pin 32 are moved forward and backward in the crossing direction to close the gate 25 and pressurize the molten metal 1 in the hot water pool 23. The time until the molten metal 1 filled in the cavity 40 is pressurized can be shortened, and the pressurized replenishment of the molten metal 1 corresponding to the solidification shrinkage volume in the cavity 40 can be performed without any trouble. Thereby, it becomes possible to improve the quality of a cast product.

DESCRIPTION OF SYMBOLS 1 Molten metal 10 Pressurizing chamber 11 Holding chamber 12 Stopper 13 Fixing plate 14 Gas supply path 16 Hot water level detection rod 17 Stoke 17a Hot water outlet 20 Fixed plate 21 Fixing die 22 Gate seal pin 23 Hot water reservoir 24 Hot water reservoir former 25 Hot water inlet 26 Piston cylinder 27 Piston mechanism 28 Gas introduction path 30 Movable plate 31 Movable mold 32 Pressure pin 32a Pressure rod 33 Pressure sleeve 34 Pressure cylinder 40 Cavity 41 Runway 100 Casting apparatus 101 Mold part

Claims (5)

A mold for forming a cavity having an opening below;
A pressurizing chamber that is disposed in the vicinity of the mold and accommodates the molten metal and supplies the molten metal into the cavity through the stalk from below the opening;
A gate seal pin that is disposed so as to be movable back and forth with respect to the opening,
Pressurization for pressurizing the molten metal filled in the hot water reservoir, which is arranged to be able to advance and retreat in a direction intersecting with the forward and backward direction of the gate seal pin with respect to the hot water reservoir which is communicated with the cavity and formed above the opening. A casting apparatus comprising a pin. Pressurizing means for supplying gas to the sealed space of the pressurizing chamber to pressurize the pressurizing chamber;
The casting apparatus according to claim 1, further comprising a decompression unit that exhausts gas from the cavity to decompress the inside of the cavity. The casting apparatus according to claim 1, wherein the mold is a horizontal mold in which a movable mold provided on the movable plate is opened and closed in a horizontal direction with respect to a fixed mold provided on the fixed platen. A mold that forms a cavity having an opening below; a pressurization chamber that is disposed in the vicinity of the mold to store the molten metal and supplies the molten metal into the cavity through stalk from below the opening; and the opening A gate seal pin that is arranged so as to be able to move forward and backward, and is openable / retractable in a direction that intersects with the forward / backward direction of the gate seal pin with respect to a hot water pool that communicates with the cavity and is formed above the opening. A casting method by a casting apparatus comprising a pressure pin that pressurizes the molten metal that is disposed in the hot water pool,
Filling the hot water pool through the stalk and the opening from the pressurizing chamber;
Filling the cavity continuously with the molten metal filled in the hot water pool;
Advancing the gate seal pin to close the opening;
And a step of advancing the pressure pin after the opening is closed to replenish the molten metal in the hot water pool into the cavity.   The casting method according to claim 4, wherein in the pressurizing and replenishing step, molten metal corresponding to a solidification shrinkage volume in the cavity is replenished from the hot water pool.

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