JP6489500B2 - Casting apparatus and casting method - Google Patents

Description

  The present invention relates to a casting apparatus and a casting method. More specifically, the present invention relates to a casting apparatus and a casting method using a predetermined divided mold, a divided casing, and a cylinder when filling a metal melt into a cavity.

  2. Description of the Related Art Conventionally, a suction differential pressure casting method has been proposed in which casting of thin-walled parts is possible while further suppressing the degree of heating of the molten metal and the mold temperature (see Patent Document 1).

In this suction differential pressure casting method, first, the lower part of the stalk is immersed in a molten metal held in the lower part of a pressurizing sealed holding furnace, and opened and closed to the left and right above the stalk communicated above the stalk. Install possible molds so that they can move up and down, and define a sealed chamber that covers the molds. Next, the suction open / close valve is opened through the communication pipe communicated with the sealed chamber, and the pressure in the sealed chamber is reduced to 100 Torr by a vacuum pump through the vacuum tank in a time of 1 second or less. Immediately after that, after the compressed air is sent to the holding furnace by opening the pressure on-off valve with a pressurizing device, the molten metal surface is pressurized to 0.4 to 1 kg / cm ² in a time of 1 second or less The pressure is maintained, and when the casting is solidified, the pressure reduction and the pressure holding are released.

Japanese Patent No. 2933255

  However, when the casting apparatus described in Patent Document 1 is used, there is a problem in that it is difficult to ensure sealing performance because a large sealed chamber is provided to cover the entire mold. In addition, since the sealed chamber opens and closes to the left and right, there is a problem that stalk may be crushed.

  The present invention has been made in view of such problems of the prior art. Then, an object of the present invention is to provide a casting apparatus and a casting method capable of reliably sliding the middle mold in the horizontal direction when a predetermined divided mold and a divided housing are used.

  The inventors of the present invention have made extensive studies in order to achieve the above object. As a result, the present inventors have found that the above object can be achieved by using a predetermined divided mold, a divided casing, and a cylinder when filling the cavity with the molten metal, and have completed the present invention. .

That is, the casting apparatus of the present invention includes a divided mold, a divided housing, a cylinder, a cavity suction device, and a pressure device . The divided mold includes a lower mold, an intermediate mold that slides horizontally on the lower mold, and an upper mold. Further, the divided housing has a fixed lower housing portion to which the lower mold is attached and a movable housing upper portion to which the upper mold is attached, and the middle mold is closed on the lower mold, A cavity and a chamber are formed by closing the upper part of the movable casing on the lower part of the divided stationary casing. Further, the cylinder is disposed outside the chamber, and is used for slidingly driving the middle mold, and the cylinder rod penetrates the lower part of the stationary housing and is engaged with the middle mold. Further, the casting apparatus is configured such that the molten metal held in the holding furnace disposed at the lower part of the divided mold is connected to the cavity formed by the divided mold, the upper end is connected to the gate of the divided mold, and the lower end. Is filled through a stalk immersed in a molten metal held in a holding furnace to produce a molded product. Further, the cavity suction device decompresses the cavity through a cavity pipe connected to the upper mold. Further, the pressurizing device supplies at least the molten metal held in the holding furnace by pressurization inside the holding furnace. Furthermore, the suction device for a cavity supplies the molten metal supplied to at least the gate to the whole cavity.

Further, the casting method of the present invention includes a lower mold, a middle mold that slides horizontally on the lower mold, and a divided mold having an upper mold, and a lower part of the stationary housing and an upper mold on which the lower mold is mounted. The cylinder is arranged outside the chamber using a split casing having an upper part of the movable side casing, and is used for slidingly driving the middle mold. The cylinder rod penetrates the lower part of the fixed side casing, with a closed medium mold by mold engaged with that cylinder, as the closed state of the movable-side housing top by fixed casing on the lower, as the step of forming the cavity and the chamber (1) After the step (1), at least the inside of the chamber is depressurized via the chamber piping connected to the upper part of the movable housing by the chamber suction device, and after the step (1), the cavity And a step (4) of depressurizing the cavity through a cavity pipe connected to the upper mold by a suction device for use, wherein the lower part of the divided mold is placed in the cavity formed by the divided mold. The molten metal held in the holding furnace disposed in is filled through a stalk whose upper end is connected to the gate of the split mold and whose lower end is immersed in the molten metal held in the holding furnace. When manufacturing a molded article, after the step (1) and before the steps (3) and (4), the molten metal held in the holding furnace by pressurization inside the holding furnace by the pressurizing device. Is a casting method that includes a step (2) of supplying at least to the gate, and in step (4), supplying at least the molten metal supplied to the gate to the entire cavity .

According to the present invention, the lower mold, the middle mold that slides horizontally on the lower mold, and the divided mold having the upper mold, the lower part of the fixed side housing on which the lower mold is mounted, and the movable side on which the upper mold is mounted A cylinder that is arranged outside the chamber using a split housing having an upper part of the housing, and for driving the middle mold to slide, and the cylinder rod penetrates the lower part of the stationary housing and is engaged with the middle mold. The middle mold is closed by the cylinders that are combined, and the upper part of the movable side casing is closed on the lower part of the fixed side casing to form a cavity and a chamber . Metal whose upper end is connected to the pouring gate of the split mold and the lower end is held in the holding furnace by pressurizing the inside of the holding furnace arranged in the lower part of the split mold Soaked in molten metal Supply the molten metal supplied to at least the gate through Stoke, and then reduce the pressure of the cavity through the piping for the cavity connected to the upper mold by the suction device for the cavity. By supplying to the whole, it was set as the structure which fills the cavity formed with the split mold, and manufactures a molded article . Therefore, it is possible to provide a casting apparatus and a casting method capable of surely slidingly driving the middle mold in the horizontal direction when the divided mold having the middle mold and the divided housing that can be opened and closed in the vertical direction are used. .

FIG. 1 is an explanatory view schematically showing a casting apparatus according to the first embodiment of the present invention. FIG. 2 is an explanatory view schematically showing the chamber piping and the chamber suction device shown in FIG. FIG. 3 is an explanatory view schematically showing a casting apparatus according to the second embodiment of the present invention. FIG. 4 is an explanatory view schematically showing an example of a casting method using the casting apparatus according to the first or second embodiment of the present invention. FIG. 5 is a perspective view schematically showing a molded product obtained by another example of the casting method using the casting apparatus according to the first or second embodiment of the present invention.

  Hereinafter, a casting apparatus and a casting method according to an embodiment of the present invention will be described in detail. In addition, the dimension ratio of drawing quoted below is exaggerated on account of description, and may differ from an actual ratio.

(First embodiment)
First, a casting apparatus according to a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing a casting apparatus according to the first embodiment of the present invention. FIG. 2 is an explanatory view schematically showing the chamber piping and the chamber suction device shown in FIG.

  As shown in FIG. 1, the casting apparatus 1 of the present embodiment includes a divided mold 10, a divided housing 20, a chamber suction device 30, a cavity suction device 40, a cylinder 50, and a holding furnace 60. , Stoke 70, pressurizing device 80, sensor 90, and control device 100. In addition, the casting apparatus 1 has a metal melt C such as aluminum or aluminum alloy in the cavity A in which the core B composed of the top core B1, the water jacket core B2 and the port core B3 is disposed, for example. A molded product such as a cylinder head (not shown) is filled to manufacture.

  The divided mold 10 is used for forming the cavity A, and includes a lower mold 11, a middle mold 13 that slides horizontally on the lower mold 11, and an upper mold 15. Moreover, the division | segmentation casting_mold | template 10 is comprised by the conventionally well-known metal mold | die applicable with respect to the molten metal C, such as aluminum and aluminum alloy, for example. Further, the core B and the baseboard added to the core B are configured by conventionally known cores and baseboards that can be applied to the molten metal C such as aluminum or aluminum alloy.

  The divided housing 20 is used for forming the chamber D and includes a fixed housing lower portion 21 to which the lower mold 11 is attached and a movable housing upper portion 23 to which the upper mold 15 is attached. Note that a rubber seal member 25 is disposed at a contact portion between the fixed-side housing lower portion 21 and the movable-side housing upper portion 23, and a sealing property between them is ensured. Moreover, as the division | segmentation housing | casing 20, if it has the pressure | voltage resistance and heat resistance with respect to the change of the pressure, temperature, etc. in a casting process, it will not specifically limit, for example. For example, a divided housing made of the same material as the divided mold may be used, but a divided housing made of a different material may be used. In addition, for example, a divided housing made of different materials may be used depending on the environment to which each divided housing is applied. Although not shown, the lower mold and the lower part of the fixed casing can be attached / detached, and the upper mold and the upper part of the movable casing can also be attached / detached.

  Here, the cavity A and the chamber D are formed by closing the middle mold 13 on the lower mold 11 and closing the divided casing 20.

  The chamber suction device 30 decompresses at least the inside of the chamber D via the chamber pipe 32 connected to the chamber D, preferably the upper part of the movable housing. Although not particularly limited, it is preferable that the chamber pipe 32 is disposed on the movable casing upper portion 23 which is not easily affected even when the molten metal leaks into the chamber D.

  Here, the chamber piping and the chamber suction device will be described in detail with reference to the drawings.

  As shown in FIG. 2, the chamber suction device 30 includes, for example, a pump 30 </ b> A for sucking (depressurizing) the sealed space to a vacuum or the vicinity thereof. As shown in FIG. 2, the main pipe 32A provided with the chamber suction device 30 is a pressure sensor 31 for detecting the pressure inside the chamber D and the suction flow rate of the main pipe 32A. A throttle valve 33 for adjusting the pressure, an opening / closing valve 35 for controlling the suction of the main pipe 32A, a pressure sensor 37 for detecting the suction pressure of the suction device 30 for the chamber, and a tank 39 for removing foreign matter sucked during the suction. Is arranged. Further, as shown in FIG. 2, the sub-pipe 32B branched from the main pipe 32A includes a throttle valve 34 that adjusts the suction flow rate through the sub-pipe 32B when opening to the atmosphere, and an open / close valve that controls suction through the sub-pipe 32B. 36 is arranged.

  Further, the cavity suction device 40 decompresses the cavity A to the cavity A, preferably via the cavity pipe 42 connected to the upper mold 15. Although not shown, the cavity pipe and the cavity suction apparatus have the same configuration as the chamber pipe and the chamber suction apparatus described above. Moreover, although not shown in figure, the porous body which suppresses the penetration | invasion of a molten metal is arrange | positioned in the cavity connection part of piping for cavities.

  The cylinder 50 is disposed outside the chamber D, and is used for driving the middle mold 13 to slide in the horizontal direction. For example, the cylinder 50 includes a cylinder rod 51, a cylinder 53, and a holding portion 55. However, the present invention is not limited to this, and a conventionally known actuator can be used. Further, although not particularly limited, it is preferable that the holding portion 55 also functions as a holder for the divided mold 20. Further, the cylinder rod 51 passes through the fixed housing lower part 21 and is engaged with the middle mold. This is because the fixed housing lower part 21 hardly moves as compared with the movable housing upper part 23, and it is not necessary to move the cylinder together. Although not shown, a seal member is provided between the cylinder rod and the lower part of the stationary housing to ensure sealing performance between them and to prevent the cylinder rod from sliding. Further, although not shown, a similar cylinder may be provided that is disposed outside the chamber and used for sliding the upper mold in the vertical direction.

  On the other hand, the holding furnace 60 is disposed outside the chamber D and below the split mold 10 in a state where the cavity A is formed. The holding furnace 20 holds the molten metal C.

  Further, the stalk 70 is a flow path of the molten metal C filled in the cavity A, the metal having the upper end portion 70 a connected to the gate 10 a of the divided mold 10 and the lower end portion 70 b held by the holding furnace 60. It is immersed in the molten metal C. Although not shown, a conventionally known porous body is disposed at the gate.

  Further, the pressurizing device 80 pressurizes the inside of the holding furnace 60 through a pipe 82 connected to the holding furnace 60. At this time, the pressurizing device 80 may supply the molten metal C held in the holding furnace 60 to the gate 10a.

  Examples of the sensor 90 include a sensor having a mold closing sensor 91 for detecting mold closing, but the sensor 90 is not limited to this. That is, although not shown, in addition to this, a molten metal spout arrival sensor for detecting the arrival of the molten metal to the spout, a cavity metal melt filling sensor for detecting the filling of the molten metal in the cavity, and the cavity It is also possible to apply one having a cavity molten metal solidification sensor for detecting solidification of the molten metal.

  Examples of the mold closing sensor 91 include a mold closing sensor to which a conventionally known positioning sensor is applied.

  As the metal melt gate arrival sensor, for example, a temperature sensor disposed in the vicinity of the gate, and a melt surface height sensor or a pressure sensor disposed in the holding furnace can be applied.

  Examples of the cavity metal melt filling sensor include, for example, a temperature sensor and a pressure sensor disposed in a cavity pipe in the vicinity of the cavity, and a molten metal height sensor disposed in a holding furnace. A pressure sensor or the like can be applied.

  Furthermore, as the cavity metal melt solidification sensor, for example, a temperature sensor disposed in a cavity pipe in the vicinity of the cavity can be applied.

  For example, the control device 100 controls the pressurizing device 80 according to an input from the mold closing sensor 91, and according to an input from at least one of the mold closing sensor 91 and the pressurizing device 80. An integrated or separate control device that controls the chamber suction device 30 and controls the cavity suction device 40 according to input from at least one of the mold closing sensor 91 and the pressurizing device 80 is applied. can do.

  In the case of applying such a control device, for example, control data for controlling pressurization and suction according to the position, pressure, temperature, elapsed time from mold closing, and the like acquired in advance by a preliminary experiment are stored in the control device. Store it.

  However, the control device is not limited to the one described above. That is, although not shown in the figure, as a control device, for example, input from at least one of a mold closing sensor, a pressurizing device, a molten metal arrival sensor, a cavity metal melt filling sensor, and a cavity metal melt solidification sensor And controlling the pressurizing device in response to an input from at least one of a mold closing sensor, a pressurizing device, a molten metal spout arrival sensor, a cavity metal melt filling sensor, and a cavity metal melt solidification sensor. Controlling the suction device for the chamber, and adjusting the cavity in response to an input from at least one of a mold closing sensor, a pressurizing device, a metal melt arrival sensor, a cavity metal melt filling sensor, and a cavity metal melt solidification sensor. An integral or separate control device for controlling the tee suction device can also be applied.

  When such a control device is applied, for example, pressurization and suction may be controlled by an actual position, temperature, pressure, and the like without considering the elapsed time from mold closing. Of course, control data for controlling pressurization and suction may be stored in the control device according to the pressure or temperature acquired in advance by a preliminary experiment. In addition, each control data mentioned above can be suitably set by the preliminary experiment using various sensors, such as the mold closing sensor mentioned above, a molten metal pouring arrival sensor, a cavity metal molten metal filling sensor, a cavity metal molten metal solidification sensor. .

  When the casting apparatus 1 manufactures a molded product, the cylinder 50 and the like disposed outside the chamber D slides horizontally on the lower mold 11, the lower mold 11, and the upper mold 15. On the lower mold 11 using the divided mold 10 having the lower mold 11 and the divided casing 20 having the fixed lower casing portion 21 to which the lower mold 11 is mounted and the fixed casing upper portion 23 to which the upper mold 15 is mounted. The cavity A and the chamber D are formed with the middle mold 13 closed and the divided housing 20 closed.

  Further, when the casting apparatus 1 manufactures a molded product, the chamber suction device 30 depressurizes the inside of the chamber D to the chamber D, preferably via the chamber pipe 32 connected to the upper part 23 of the movable housing. May be.

  Further, when the casting apparatus 1 manufactures a molded product, the cavity suction device 40 reduces the pressure of the cavity A to the cavity A, preferably via the cavity pipe 42 connected to the upper mold 15. The pressure may be reduced. At this time, the cavity suction device 40 itself may supply the molten metal C to the entire cavity A. Further, as described above, the cavity suction device 40 may supply the molten metal C supplied to at least the gate 10a by the pressurizing device 80 to the entire cavity A.

  Further, when the casting apparatus 1 manufactures a molded product, the pressurizing apparatus 40 pressurizes the inside of the holding furnace 60 via the pipe 82 connected to the holding furnace 60, and the molten metal held in the holding furnace 60. You may make it supply C to the gate 10a.

  As described above, a predetermined divided mold, a divided casing, and a cylinder are provided, and the middle mold is closed on the lower mold of the predetermined divided mold by the predetermined cylinder, and the predetermined divided casing is closed. As described above, by forming the cavity and the chamber, the middle mold can be reliably slid in the horizontal direction. As a result, the stalk is not crushed by the divided housing that is driven to slide, and the chamber volume can be reduced, so that sealing performance can be ensured. In addition, since the divided casing can be opened and closed in the vertical direction, the divided mold can be easily taken out, and a mold internal cleaning process (including an operation of replacing the pouring filter porous body performed as necessary) described later is performed. There is also a secondary advantage that the core set preparation work process, the core air blow process, and the like can be facilitated.

  Moreover, in the casting apparatus of the present embodiment, as described above, it is preferable that the holding part of the cylinder also serves as the holding part of the lower part of the fixed housing. By adopting such a configuration, the relative position between the cylinder and the lower part of the stationary housing is maintained, and the middle mold can be slid in the horizontal direction more reliably.

  Furthermore, in the casting apparatus of the present embodiment, as described above, the chamber suction apparatus that decompresses at least the interior of the chamber via the chamber pipe connected to the upper part of the movable casing and the upper mold are connected. And a cavity suction device for decompressing the cavity via the cavity pipe. By adopting such a configuration, it is possible to reduce the dependence on the clearance of the dividing mold, the cavity volume, and the chamber volume outside the cavity in the degree of decompression and the decompression speed. Therefore, the degree of decompression and the decompression speed can be stabilized in an appropriate range, and the filling property of the molten metal can be improved, such as the casting speed can be increased. In addition, air inflow from the clearance of the split surface of the split mold, which can occur when the cavity is directly decompressed using only the cavity suction device, is suppressed or prevented, and defects due to air entrainment can be reduced. This makes it possible to improve the filling property of the molten metal.

  Further, in the casting apparatus of the present embodiment, as described above, the molten metal held in the holding furnace disposed at the lower part of the divided mold is inserted into the cavity formed by the divided mold, and the upper end portion of the divided mold is used. Is a casting apparatus for producing a molded product by filling through a stalk immersed in a molten metal whose lower end is held in a holding furnace and held by pressurization inside the holding furnace. And a pressurizing device that supplies the molten metal held in the furnace to at least the pouring gate, and the cavity suction device preferably supplies the molten metal supplied to at least the pouring gate to the entire cavity. By setting it as such a structure, the filling property of a molten metal can further be improved.

  In other words, by using the pressurizing device to pressurize the inside of the holding furnace, supplying the molten metal to at least the gate, the molten metal held in the holding furnace can be divided using the divided mold and the core. There is no need to supply by suction to the gate through a cavity having a complicated shape to be formed. For this reason, it is not necessary to consider the suction resistance in the cavity having a complicated shape, which is an impediment to improving the filling property. Further, the inflow of air from the clearance of the split surface of the split mold, which can occur when the cavity is directly decompressed using only the cavity suction device, is suppressed or prevented. This reduces energy loss used in manufacturing and reduces defects due to air entrainment, compared to supplying molten metal to the entire cavity using only the cavity suction device. This makes it possible to improve the filling property of the molten metal.

  Although not particularly limited, the present invention is a low-pressure casting method in which the molten metal is filled into the cavity at low speed and low pressure, rather than being applied to the die casting method in which the molten metal is filled into the cavity at high speed and high pressure. It is effective to apply to. This is because the air flowing in the low-pressure casting method and the air that originally exists are easier to reduce the filling property of the molten metal than the air flowing in the die-casting method.

  In the casting apparatus of this embodiment, it is preferable that the final ultimate internal pressure of the chamber by the chamber suction device is lower than the final ultimate internal pressure of the cavity by the cavity suction device.

  That is, at the final ultimate pressure, if the internal pressure of the chamber is made lower than the internal pressure of the cavity, which will be described later, defects due to air entrainment can be reduced, and the filling property of the molten metal can be further improved.

  Furthermore, in the casting apparatus according to the present embodiment, as described above, the mold closing sensor for detecting mold closing and the pressurizing device are controlled in accordance with the signal from the mold closing sensor, so that the mold closing sensor The chamber suction device is controlled in response to a signal from at least one of the pressure devices, and the cavity suction device is controlled in response to a signal from at least one of the mold closing sensor and the pressure device. It is preferable to provide an integral or separate control device.

  As described above, when the predetermined pressure is applied by the pressurizing device, the predetermined suction (decompression) is performed by the chamber suction device, and the predetermined suction (decompression) is performed by the cavity suction device. It is possible to further reduce the energy loss used at the time, further stabilize the casting speed within an appropriate range, and reduce defects due to air entrainment. Thereby, the filling property of the molten metal can be further improved.

(Second Embodiment)
Next, a casting apparatus according to a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 3 is an explanatory view schematically showing a casting apparatus according to the second embodiment of the present invention. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 3, the casting apparatus 1 </ b> A of the present embodiment uses a split mold 10 having a communication path 10 b that communicates the cavity A and the space Da of the chamber D that is outside the split mold 10. Is different. In addition, 10b shown by the dotted line in FIG. 3 is a communication path arranged at a position where it does not interfere with the chamber pipe 42. Further, as shown in FIG. 3, a top core B1 and a port core B3 are disposed with respect to the suction port 10c of the communication path 10b. Moreover, 13A and 15A which are each shown with the continuous line and dotted line in a figure are the steel materials similar to the middle mold 13 and the upper mold 15 used in order to form the very thin communication path | route 10a.

  In the suction differential pressure casting method described in Patent Document 1, no study has been made on the production of a molded product having a complicated shape that is formed using a core together with a divided mold. Therefore, in the manufacture of a molded product having a complicated shape that is formed using a core together with a split mold, the core generated by burning the adhesive contained in the core when the molten metal contacts the core Gas defects may occur due to the gas, and this may also reduce the filling properties of the molten metal.

  On the other hand, in the casting apparatus of the present embodiment, as described above, by using a split mold having a communication path that connects the cavity and the space of the chamber that is the outside of the split mold, the molten metal is contained in the middle. When the adhesive contained in the core comes into contact with the core, the core gas generated by combustion or the like can be released through the communication path, and the rise in pressure in the cavity can be reduced. As a result, even if the core gas or the like cannot be discharged from the cavity pipe, the core gas or the like can be discharged through the communication path, so that gas defects can be reduced. The filling property of the molten metal can be improved.

  Here, as the communication path, for example, an extremely narrow passage resistance and a large passage resistance can be cited. As a result, the pressure is not reduced immediately after the pressure inside the chamber. On the other hand, this makes it impossible to directly discharge the core gas and the like from the cavity through the cavity pipe, and can discharge the core gas and the like through the communication path when the pressure of the cavity increases. .

  In the casting apparatus of the present embodiment, as described above, it is preferable that the core or the baseboard added to the core is disposed with respect to the suction port of the communication path.

  In this way, by arranging the core and the baseboard with respect to the suction port of the communication path, the core generated by burning the adhesive contained in the core when the molten metal contacts the core Gas can be efficiently released through the communication path and the chamber piping. In addition, it is possible to further stabilize the casting speed within an appropriate range and reduce defects due to air entrainment. Thereby, the filling property of the molten metal can be further improved, for example, gas defects can be further reduced.

  Furthermore, in the casting apparatus of this embodiment, it is preferable that the communication path is formed in at least one of the middle mold, the upper mold, and between the middle mold and the upper mold.

  In this way, by forming the communication path between the middle mold and the upper mold, between them, the core gas generated by the burning of the adhesive contained in the core when the molten metal contacts the core is generated. It is possible to escape efficiently through the communication path and the chamber piping. In addition, it is possible to further stabilize the casting speed within an appropriate range and reduce defects due to air entrainment. Thereby, the filling property of the molten metal can be further improved, for example, gas defects can be further reduced.

(Third embodiment)
Next, a casting method according to the third embodiment of the present invention, specifically, a casting method using the casting apparatus according to the first or second embodiment of the present invention will be described in detail. In addition, although the casting method of this invention does not necessarily need to use the casting apparatus of this invention, it is preferable to use the casting apparatus of this invention.

  The casting method of this embodiment includes the step (1), and preferably includes the step (3) and the step (4). Here, the step (1) is used for forming the cavity, and is used for forming the lower mold, the divided mold including the middle mold that slides horizontally on the lower mold, and the upper mold, and the chamber. A cylinder that is arranged outside the chamber using a lower part of the fixed side case to which the upper mold is attached and a lower part of the movable side case to which the upper mold is attached. The cylinder rod passes through the lower part of the fixed side casing, and the middle mold is closed on the lower mold by the cylinder engaged with the middle mold, and the upper part of the movable side case is fixed on the lower part of the fixed side casing. Is a process of forming a cavity and a chamber in a closed state. Further, the step (3) is a step in which at least the inside of the chamber is depressurized by the chamber suction device after the step (1) through the chamber pipe connected to the upper part of the movable housing. Further, the step (4) is a step of decompressing the cavity after the step (1), preferably after the step (3), through the cavity pipe connected to the upper mold by the cavity suction device. is there.

  Thus, the lower mold, the middle mold that slides horizontally on the lower mold, and the divided mold having the upper mold, the lower part of the fixed side casing on which the lower mold is mounted, and the movable side casing on which the upper mold is mounted A cylinder that is arranged outside the chamber using a divided housing having an upper portion and slide-drives the middle mold, and the cylinder rod penetrates the lower portion of the solid side housing and engages with the middle mold. The middle mold is closed on the lower mold by the cylinder, and the upper part of the movable casing is closed on the lower part of the fixed casing, thereby forming the cavity and the chamber. It can be surely slid in the horizontal direction. As a result, the stalk is not crushed by the divided housing that is driven to slide, and the chamber volume can be reduced, so that sealing performance can be ensured. In addition, since the divided casing can be opened and closed in the vertical direction, the divided mold can be easily taken out, and a mold internal cleaning process (including an operation of replacing the pouring filter porous body performed as necessary) described later is performed. There is also a secondary advantage that the core set preparation work process, the core air blow process, and the like can be facilitated.

  By including step (3) and step (4), it is possible to reduce the dependence on the clearance of the dividing mold, the cavity volume, and the chamber volume outside the cavity in the degree of reduced pressure and the reduced pressure speed. it can. Therefore, the degree of decompression and the decompression speed can be stabilized in an appropriate range, and the filling property of the molten metal can be improved, such as the casting speed can be increased. In addition, air inflow from the clearance of the split surface of the split mold, which can occur when the cavity is directly decompressed using only the cavity suction device, is suppressed or prevented, and defects due to air entrainment can be reduced. This makes it possible to improve the filling property of the molten metal.

  In the casting method of the present embodiment, the molten metal held in the holding furnace disposed at the lower part of the divided mold is connected to the cavity formed by the divided mold, and the upper end portion is connected to the gate of the divided mold. And when manufacturing a molded article by filling the lower end portion through the stalk immersed in the molten metal held in the holding furnace, after the step (1) and after the step (3) and the step ( 4) includes a step (2) of supplying the molten metal held in the holding furnace to at least the gate by pressurizing the inside of the holding furnace by the pressurizing device, and in step (4), the molten metal is supplied to at least the gate. It is preferable to supply the molten metal to the entire cavity. Thereby, the filling property of the molten metal can be further improved.

  In other words, by using the pressurizing device to pressurize the inside of the holding furnace, supplying the molten metal to at least the gate, the molten metal held in the holding furnace can be divided using the divided mold and the core. There is no need to supply by suction to the gate through a cavity having a complicated shape to be formed. For this reason, it is not necessary to consider the suction resistance in the cavity having a complicated shape, which is an impediment to improving the filling property. Further, the inflow of air from the clearance of the split surface of the split mold, which can occur when the cavity is directly decompressed using only the cavity suction device, is suppressed or prevented. This reduces energy loss used in manufacturing and reduces defects due to air entrainment, compared to supplying molten metal to the entire cavity using only the cavity suction device. This makes it possible to improve the filling property of the molten metal.

  In the casting method of the present embodiment, when the predetermined pressure is applied by the pressurizing device, the predetermined suction (decompression) is performed by the chamber suction device and the predetermined suction (decompression) is performed by the cavity suction device. It is preferable to

  Here, the predetermined pressurization by the pressurizing device means that pressurization of the inside of the holding furnace by the pressurizing device is started, and then the inside of the holding furnace by the pressurizing device is increased until the molten metal reaches the gate. The pressure is continued, and pressurization inside the holding furnace by the pressurizing device is continued or maintained until the molten metal is supplied to the entire cavity, and further, the molten metal is solidified until the molten metal in the entire cavity is solidified. It means that the pressurization inside the holding furnace is continued or held by the pressure device, and then the pressurization inside the holding furnace by the pressurization device is terminated.

  In addition, the predetermined suction (decompression) by the suction device for the chamber refers to the chamber by the suction device for the chamber from the start of pressurization inside the holding furnace by the pressurization device until the molten metal reaches the gate. Preferably, pressure reduction inside the chamber is started via the chamber piping connected to the upper part of the movable housing, and then the chamber suction pipe is used until the molten metal is supplied to the entire cavity. Continue or maintain the reduced pressure inside the chamber, and further continue or hold the reduced pressure inside the chamber via the chamber piping by the chamber suction device until the molten metal in the entire cavity is solidified, When the pressurization of the inside of the holding furnace by the pressurizer is finished, the chamber is connected via the chamber pipe by the chamber suction device. You say that you want to exit the interior of the reduced pressure. Although not particularly limited, it is preferable that the internal pressure of the chamber is lower than the internal pressure of the cavity described later at the final ultimate pressure. With such a configuration, it is possible to reduce defects due to air entrainment, and it is possible to further improve the filling property of the molten metal.

  Further, the predetermined suction (decompression) by the cavity suction device means that when the molten metal reaches the gate, the cavity pipe connected to the upper mold is preferably connected to the cavity by the cavity suction device. The pressure reduction of the cavity through the cavity piping is continued by the suction device for the cavity until the molten metal is supplied to the entire cavity, and then the cavity is started. Cavity depressurization via cavity piping by cavity suction device between the time when the molten metal is supplied to the whole and the end of the pressure reduction inside the chamber via chamber piping by the chamber suction device It means to end.

  As described above, when the predetermined pressure is applied by the pressurizing device, the predetermined suction (decompression) is performed by the chamber suction device, and the predetermined suction (decompression) is performed by the cavity suction device. It is possible to further reduce the energy loss used at the time, further stabilize the casting speed within an appropriate range, and reduce defects due to air entrainment. Thereby, the filling property of the molten metal can be further improved.

  Further, in the casting method of the present embodiment, when the metal decompression is continued or held through the chamber piping by the chamber suction device until the molten metal is supplied to the entire cavity, or the entire cavity When the decompression inside the chamber through the chamber piping by the chamber suction device is continued or held until the molten metal of the chamber solidifies, the above-described communication path by the chamber suction device and the cavity through the chamber piping are used. After that, when the pressurization of the inside of the holding furnace by the pressurizer is finished, the decompression of the cavity through the communication path and the chamber pipe is terminated by the chamber suction device. Is preferred.

  In this way, by using the divided mold having the above-described communication path, the core gas generated by burning the adhesive contained in the core when the molten metal contacts the core is connected to the communication path and the chamber piping. Can be escaped through. Thereby, the filling property of the molten metal can be further improved, for example, gas defects can be reduced.

  Hereinafter, the casting method of this embodiment will be described in detail with reference to the drawings. FIG. 4 is an explanatory view schematically showing an example of a casting method using a casting apparatus according to an embodiment of the present invention.

  As shown in FIG. 4, in the casting method of this example, as a previous step of the casting step of step (E), a conventionally known mold internal cleaning step (step (A)), core set preparation work step (step ( B)), a core air blow process (process (C)) and a mold closing process (process (D)), and a conventionally known cooling process (process (F)) and mold opening process as a subsequent process of the casting process. (Step (G)).

  Here, L1 shows the pressure inside a holding furnace, for example, the value detected by the pressure sensor arrange | positioned by piping is applicable. However, it is not limited to this, For example, the value of the pressurization force by a pressurization apparatus can also be applied. L2 indicates the pressure inside the chamber, and for example, a value detected by a pressure sensor provided in the chamber piping can be applied. However, it is not limited to this, For example, the value of the decompression force by the chamber suction device can also be applied. Further, L3 indicates the pressure of the cavity, and for example, a value detected by a pressure sensor disposed in the cavity pipe can be applied. However, it is not limited to this, For example, the value of the decompression force by a cavity suction device can also be applied.

  First, as indicated by L1, pressurization of the inside of the holding furnace by the pressurizing device is started at T1 indicating when the mold is closed. Subsequently, pressurization of the inside of the holding furnace by the pressurizer is continued until T2 indicating when the molten metal reaches the gate. Furthermore, pressurization of the inside of the holding furnace by the pressurizing device is continued or held until T3 indicating when the molten metal is supplied to the entire cavity. Furthermore, the internal pressure of the holding furnace by the pressurizer is continued or held until T4, which indicates when the molten metal in the entire cavity is solidified, and then the internal pressurization of the hold furnace by the pressurizer is terminated. To do. T5 indicates the time when the pressurization by the pressurization device (and the decompression by the chamber suction device described later) is released, and T6 indicates the time when the temperature of the molded product is lowered to a mold-releasing strength.

  In addition, as indicated by L2, the chamber suction chamber is used for the chamber between T1 indicating the start of pressurization inside the holding furnace by the pressurizing device and T2 indicating the time when the molten metal reaches the gate. Depressurization inside the chamber is started via the connected chamber piping. Next, the vacuum inside the chamber is continued through the chamber piping by the chamber suction device until T3 indicating that the molten metal is supplied to the entire cavity, and further, the molten metal in the entire cavity is solidified. The pressure inside the chamber is continued through the chamber piping by the chamber suction device until T4 indicates. Thereafter, at T5 indicating the end of pressurization of the inside of the holding furnace by the pressurizer, the decompression of the interior of the chamber via the chamber pipe by the chamber suction device is terminated.

  Further, as indicated by L3, at T2 indicating when the molten metal has reached the gate, pressure reduction of the cavity via the cavity pipe connected to the cavity by the cavity suction device is started. Next, decompression of the cavity through the cavity piping by the cavity suction device is continued until T3 indicating that the molten metal is supplied to the entire cavity. Thereafter, during the period from T3 when the molten metal is supplied to the entire cavity to the end of the decompression of the inside of the chamber through the chamber piping by the chamber suction apparatus, the cavity by the cavity suction apparatus End the decompression of the cavity through the service pipe.

  Next, a molded product obtained by casting will be described in detail with reference to the drawings. FIG. 5 is a perspective view schematically showing a molded product obtained by another example of the casting method using the casting apparatus according to the first or second embodiment of the present invention.

  As shown in FIG. 5, the molded product E is a cylinder head made of aluminum alloy and has a shape corresponding to the shape of the cavity of the divided mold. In addition, Ea in a figure shows the burr | flash derived from a communication path or piping for cavities.

  As mentioned above, although this invention was demonstrated by some embodiment, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.

  For example, in the said embodiment, although aluminum and aluminum alloy were illustrated as a metal molten metal, it is not limited to this, For example, iron, copper, brass, etc. are applicable.

  For example, in the above-described embodiment, the cylinder head is exemplified as a molded product having a complicated shape that is formed by using a divided mold and a core. However, the present invention is not limited to this, and the cylinder block is not limited thereto. Can also be applied.

  Further, for example, in the above-described embodiment, the case of using a pressurizing device that pressurizes the inside of the holding furnace when supplying the molten metal to the gate is illustrated, but the present invention is not limited to this. Instead, the molten metal may be supplied to at least the gate using an electromagnetic pump.

DESCRIPTION OF SYMBOLS 1,1A Casting device 10 Divided mold 10a Cup 10b Communication path 10c Suction port 11 Lower mold 13 Middle mold 13A, 15A Steel 15 Upper mold 20 Divided casing 21 Fixed casing lower section 23 Movable casing upper section 25 Rubber seal member 30 Chamber suction device 30A Pump 31, 37 Pressure sensor 32 Chamber piping 32A Main piping 32B Sub piping 33, 34 Throttle valve 35, 36 Open / close valve 39 Tank 40 Cavity suction device 42 Cavity piping 50 Cylinder 51 Cylinder rod 53 Cylinder 55 Holding part 60 Holding furnace 70 Stoke 70a Upper end part 70b Lower end part 80 Pressurizing device 82 Piping 90 Sensor 91 Mold closing sensor 100 Control unit A Cavity B Core B1 Top core B2 Water jacket core B Port core C the molten metal D chamber Da space E moldings Ea burrs

Claims (4)

A divided mold having a lower mold, a middle mold that slides horizontally on the lower mold, and an upper mold;
A split housing having a lower part of a fixed side housing to which the lower mold is attached and an upper part of a movable side case to which the upper mold is attached, wherein the middle mold is closed on the lower mold. In addition, a split housing that forms a cavity and a chamber by closing the upper portion of the movable housing on the lower portion of the split fixed housing, and
A cylinder disposed outside the chamber for slidingly driving the middle mold, the cylinder rod penetrating through the lower part of the stationary housing and engaging the middle mold. ,
In the cavity formed by the split mold, the molten metal held in a holding furnace disposed at the lower part of the split mold is connected with the upper end of the split mold and the lower end of the split mold. A casting apparatus for producing a molded product by filling through a stalk immersed in the molten metal held in a holding furnace,
A cavity suction device for depressurizing the cavity via a cavity pipe connected to the upper mold;
A pressurizing device for supplying the molten metal held in the holding furnace by pressurization inside the holding furnace to at least the gate.
The casting apparatus, wherein the cavity suction device supplies the molten metal supplied to at least the pouring gate to the entire cavity .   The casting apparatus according to claim 1, wherein the holding part of the cylinder also serves as a holding part of the lower part of the stationary housing. Casting apparatus according to claim 1 or 2, characterized in that it comprises at least a chamber for suction equipment for reducing the pressure inside of the chamber via the chamber pipe that is connected to the movable-side housing top. A lower mold, a middle mold that slides horizontally on the lower mold, and a divided mold having an upper mold, a lower part of a fixed side casing to which the lower mold is attached, and an upper part of a movable side case to which the upper mold is attached A cylinder that is disposed outside the chamber using a split housing and for slidingly driving the middle mold, and a cylinder rod passes through the lower part of the stationary-side housing and is engaged with the middle mold. A step of forming the cavity and the chamber by closing the middle mold with the cylinders being joined and closing the upper part of the movable casing on the lower part of the fixed casing (1) When,
After the step (1), a step (3) of depressurizing at least the inside of the chamber via a chamber pipe connected to the upper part of the movable housing by a chamber suction device;
A step (4) of depressurizing the cavity via a cavity pipe connected to the upper mold by a cavity suction device after the step (1),
In the cavity formed by the split mold, the molten metal held in a holding furnace disposed at the lower part of the split mold is connected with the upper end of the split mold and the lower end of the split mold. When producing a molded product by filling through stalk immersed in the molten metal held in a holding furnace,
After the step (1) and before the step (3) and the step (4), the molten metal held in the holding furnace by pressurizing the holding furnace with a pressurizing device is used. Including at least the step (2) of supplying to the gate,
In the step (4), the molten metal supplied to at least the pouring gate is supplied to the entire cavity .

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