HK1212949B - Tilt type gravity molding device - Google Patents

Description

Inclined gravity casting device

Technical Field

The present invention relates to a casting apparatus for forming a molded article by pouring molten metal into a product forming space formed in a mold, and more particularly, to an inclined gravity casting apparatus for obtaining a molded article by pouring molten metal into a product forming space by using the own weight of the molten metal and solidifying the molten metal.

Background

The gravity casting apparatus for casting by injecting molten metal into a mold from a gate provided at an upper portion of the mold only by the gravity of the molten metal can increase a cooling rate at the time of casting, can produce a compact casting having a good casting surface/dimensional accuracy, and is particularly excellent in pressure resistance and mechanical properties. On the other hand, in such a gravity casting apparatus, a riser for compensating for a volume reduction at the time of solidification needs to be formed in an upper portion of the molded product, and a time for cooling and solidifying the riser is required in addition to the solidification time of the molded product. In addition, since the riser is formed, a larger amount of molten metal and melting cost are required, and processing cost for cutting the riser is additionally required. In order to obtain a molded article free from shrinkage cavities, it is necessary to directionally solidify the molten metal from the bottom side of the space in the mold to the riser side, and there is a problem that the solidification time of the molten metal cannot be sufficiently controlled only by forming the riser.

Therefore, as shown in fig. 10, the applicant of the present application has proposed a tilting type gravity casting apparatus 100 (patent document 1): the gate valve is provided with a shielding part 102 capable of opening and shielding the gate 101, and a gas supply part 104 capable of supplying gas into the product forming space 103. Such a tilting type gravity casting apparatus 100 can pressurize the molten metal 105 in the mold 106 by blocking the runner 101 with the blocking portion 102 that slides in the horizontal direction after the molten metal 105 is poured into the product forming space 103, and supplying gas into the mold 106 with the gas supply portion 104. Further, since the tilting gravity casting apparatus 100 pressurizes the product forming space 103 in the mold 106 with gas, no shrinkage cavity or crack occurs even if no riser is provided at all. Therefore, the tilting gravity casting apparatus 100 does not require a time for cooling and solidifying the riser, and can shorten the casting time period and reduce the manufacturing cost of the molded product. In addition, the tilting type gravity casting apparatus 100 has an effect of reducing the amount of molten metal for forming the riser, the melting cost, and the processing cost for cutting the riser.

Documents of the prior art

Patent document

Patent document 1: WO2011/089711

Disclosure of Invention

Problems to be solved by the invention

However, as shown in fig. 10, the shield portion 102 of the tilting gravity casting device 100 of patent document 1 forms a part of the runner 101 extending in the substantially vertical direction at the middle of the runner 101 in the vertical direction, and slides in the horizontal direction to close the runner 101. Therefore, when the runner 101 is closed, the space of the shielding portion 102 constituting the runner 101 becomes a closed space, and the remaining molten metal 105 is likely to solidify, which causes a problem of a defect such as clogging of the molten metal. Further, since the runner 101 is formed above the shield portion 102, the distance from the ladle (ladle)107 to the space in the mold 106 becomes long, and there is a problem that temperature control of the molten metal 105 and adjustment of the amount of molten metal become difficult.

Accordingly, an object of the present invention is to provide a tilting type gravity casting apparatus which does not require a riser, suppresses the elongation of a runner, is less likely to cause clogging of molten metal, and facilitates the temperature control of the molten metal.

Means for solving the problems

The first inclined gravity casting device of the present invention includes: a mold having a product forming space formed therein for forming a molded product, the mold receiving molten metal from a gate; a ladle having a storage section capable of storing the molten metal and a plate-shaped opening/closing body that is in contact with the mold and has an inlet that is alignable with the gate; and a gas supply unit for supplying gas to the product forming space, wherein the opening/closing body is formed in a plate shape on a lower surface of the ladle, the injection port for injecting the molten metal in the reservoir into the gate of the mold is formed on a surface abutting the mold, the opening and closing body of the ladle slides in the horizontal direction by the movement of the opening and closing hydraulic crane so that the ladle slides, and the molten metal in the storage portion can be poured from the pouring opening of the opening/closing body into the pouring gate of the mold by aligning the pouring opening of the opening/closing body with the pouring gate of the mold, and the molten metal can be changed into a closed state in which the pouring opening of the opening/closing body is shifted from the pouring opening of the mold so that the pouring opening of the opening/closing body closes the pouring gate of the mold, or can be changed from the closed state into the open state.

The second inclined gravity casting apparatus is characterized in that the gas supply unit has a gas flow path for supplying gas from outside the mold to an upper space of the product forming space, and the gas flow path is horizontally communicated with the upper space.

The third inclined gravity casting apparatus is characterized in that the gas flow path includes: an introduction flow path which communicates with the outside of the mold and introduces gas from the outside; and a supply flow path which is a flow path branched from the introduction flow path and supplies gas to an upper space of the product forming space.

Effects of the invention

According to the first tilting-type gravity casting apparatus, the ladle has the opening/closing body having the sprue formed on the surface thereof abutting against the mold, and the ladle is slid with respect to the mold, whereby the open state in which the sprue is aligned with the gate and the closed state in which the gate is closed by the opening/closing body can be switched. Therefore, when the mold is tilted to inject the molten metal stored in the storage portion of the ladle into the product forming space in the mold, the mold can be tilted in an open state in which the sprue is aligned with the gate, and the molten metal can be injected from the sprue through the gate into the product forming space. Further, when the gas is supplied to the product forming space after the molten metal is poured into the product forming space, the ladle is slid to switch to a closed state in which the opening/closing body closes the gate, and then the gas is supplied, whereby the molten metal in the product forming space can be pressurized without leaking the gas to the outside. In this way, the gate can be opened and closed by the opening and closing member provided in the ladle, and therefore, compared with a case where a device for opening and closing the runner is separately provided, the gate can be reliably closed with a simple structure, and therefore, the runner can be made less likely to be clogged with the remaining molten metal. Further, since the length of the runner can be shortened as compared with a case where a device for opening and closing the runner is separately provided, a drop in the temperature of the molten metal can be suppressed, and the temperature control of the molten metal can be facilitated. Further, since the runner is shortened, the molten metal in the runner can be suppressed from staying, and the amount of the molten metal can be easily controlled.

According to the second inclined gravity casting apparatus, the gas flow path of the gas supply unit supplies gas to the upper space of the product forming space inside the mold, and is communicated with the upper space in the horizontal direction, so that the gas is not directly injected into the molten metal stored in the product forming space inside the mold. Therefore, the molten metal can be prevented from being dented by the gas injection.

According to the third inclined gravity casting apparatus, the gas flow path includes: an introduction flow path which communicates with the outside of the mold and introduces gas from the outside; and a supply flow path which is a flow path branched from the introduction flow path and supplies gas to the upper space of the product forming space, so that gas can be supplied to the upper space inside the mold at the same pressure through the plurality of supply flow paths by flowing the gas into 1 introduction flow path, and adjustment of the flow rate and pressure of the gas can be facilitated.

Drawings

FIG. 1 is a sectional view showing the structure of a tilting type gravity casting apparatus in a standing state.

FIG. 2 is a sectional view showing the structure of an inclined gravity casting apparatus in an inverted state in which a molten metal is stored in a storage part of a ladle.

FIG. 3 is a sectional view showing a tilting type gravity casting apparatus in the middle of tilting.

FIG. 4 is a sectional view showing the structure of a tilting gravity casting apparatus in an erected state after completion of molten metal injection.

Fig. 5 is a sectional view showing the configuration of the tilting type gravity casting apparatus in a state where the gate is closed by sliding the opening/closing body.

FIG. 6 is a sectional view showing the configuration of the inclined gravity casting apparatus for explaining the configuration of the gas supply portion.

Fig. 7 is a perspective view of a tilting gravity casting apparatus showing an upper mold by a two-dot chain line and showing the shapes of gas supply portions and the upper surface of the middle mold.

Fig. 8 is a sectional view showing a state where the mold is removed from the molded article.

Fig. 9 is a view showing the tilting type gravity casting apparatus as viewed from above in an upright state.

FIG. 10 is a view showing an example of a conventional tilting type gravity casting apparatus.

Detailed Description

Hereinafter, preferred embodiments of the tilting type gravity casting apparatus 1 according to the present invention will be described with reference to the drawings. In the present embodiment, the inclined gravity casting apparatus 1 for casting a rim (tire) made of an aluminum alloy is described as an example, but the inclined gravity casting apparatus 1 may be an apparatus for casting other parts such as an engine cylinder of an automobile. The inclined gravity casting device 1 includes: a casting mold 2 which forms a product forming space 3 for forming a molded product 9 by joining a plurality of detachable metal fittings by a hydraulic cylinder, and which can be tilted into an inverted state and an upright state standing at substantially 90 degrees from the inverted state; a ladle 5 that stores a molten metal 7 such as an aluminum alloy, for example, and injects the molten metal 7 into the product forming space 3 through a gate 8 when the mold 2 is tilted; and a gas supply portion 6 that supplies gas to the upper space 4 of the product forming space 3. Hereinafter, the tilt type gravity casting apparatus 1 will be described with reference to the upright state as shown in fig. 1 without particular mention, and the vertical direction and the horizontal direction refer to the vertical or horizontal direction in the case where the mold 2 is held in the upright state. The standing state is a state in which the gate 8 opens upward, and the molten metal 7 stored in the ladle 5 is poured into the mold 2 from the gate 8. The inverted state is a state in which the gate 8 is opened in the horizontal direction, and the molten metal 7 stored in the ladle 5 is retained in the ladle 5.

The casting mold 2 is configured by fitting an upper mold 21, a lower mold 24, a middle mold 22, and 4-divisible side molds 23, and a product forming space 3 for filling a molding material 9 for forming a rim by filling molten metal 7 is formed inside. The product forming space 3 is a space including a disc (disk) forming portion 31, a boss hole forming portion 32, and a rim forming portion 33, the disc forming portion 31 is formed to form a disc-shaped disc, the boss hole forming portion 32 is formed at the center of the disc forming portion 31, and is formed thick to form a boss hole, and the rim forming portion 33 is formed annularly at the outer periphery of the disc forming portion 31 to form a rim. The upper mold 21, the lower mold 24, the middle mold 22, and the side molds 23 are controlled in their respective movements by a hydraulic crane, not shown, and the hydraulic crane is controlled so that the respective molds 21, 22, 23, and 24 are closely attached to each other when the casting mold 2 is formed. The mold 2 is fixed to a tilting device and a hydraulic crane, not shown, and can be tilted at least to 90 degrees.

As shown in fig. 6 and 8, the upper die 21 is annular, and an introduction flow path 63 is formed at an upper end portion of the upper space 4 having the product forming space 3 provided on a lower surface thereof, as shown in fig. 6 and 7, and the gas for pressurizing the product forming space 3 is introduced from the outside of the mold through the introduction flow path 63.

As shown in fig. 1, the center mold 22 is formed in a bowl shape so that the outer surface forms the shape of the inner peripheral surface of the rim and the inner side surface of the wheel disc. A gate 8 into which the molten metal 7 can be poured is formed on the upper surface of the middle mold 22. A plate-shaped opening/closing body 51 formed on the lower surface of the ladle 5 abuts on the portion of the center mold 22 where the gate 8 is provided. A slide groove 10 is formed in the middle mold 22 so that the opening and closing body 51 can slide. A supply passage 64 for supplying gas to the upper space 4 of the product forming space 3 is formed in the upper surface of the middle mold 22.

The gas supply unit 6 includes: a pump 61 for supplying high-pressure gas to the gas flow path 62; and a gas passage 62 for introducing the high-pressure gas flowing in from the pump 61 into the upper space 4 of the product forming space 3 inside the mold. The pump 61 can pressurize the high-pressure gas to enter the gas flow path, and can suck the gas in the gas flow path to apply a negative pressure. When the upper mold 21 and the middle mold 22 are combined, the introduction flow path 63 of the upper mold 21 and the supply flow path 64 of the middle mold 22 communicate with each other to constitute the gas flow path 62. By supplying the high-pressure gas to the upper space 4 of the product forming space 3 by the pump 61 in this way, the molten metal stored in the product forming space 3 can be pressurized, and the occurrence of problems such as shrinkage due to solidification and shrinkage of the molten metal can be suppressed. The supply flow path 64 is branched into a plurality of flow paths, and the ends of the branched flow paths are directed horizontally and communicate with the upper space 4 of the product forming space 3. In this way, the gas flow path 62 divides the high-pressure gas injected from the outside into the introduction flow path 63 by the pump 61 into a plurality of flow paths in the supply flow path 64 and supplies the high-pressure gas to the upper space 4 of the product forming space 3 in the horizontal direction, so that the gas is not directly injected into the molten metal 7 stored in the product forming space 3 below the upper space 4. Therefore, the molten metal 7 can be prevented from being dented by the gas injection. Further, the gas can be supplied to the upper space 4 inside the mold at the same pressure through the plurality of supply channels 64, and the adjustment of the flow rate and pressure of the gas can be facilitated. In the present embodiment, a center pump 65 for supplying gas to the boss hole forming portion 32 at the center of the mold 2 is further provided.

As shown in fig. 1, the lower mold 24 is formed in such a manner that the upper side forms the outer side surface of the rim wheel disc, and the center thereof is raised to form the lower surface of the hub hole forming portion 32. The lower mold 24 is provided therein with a cooling means, not shown, which can cool the molten metal 7 during casting. The side mold 23 is a substantially cylindrical shape having an inner periphery forming the outer peripheral surface of the rim, and is divided into 4 pieces substantially equally. The lower portion of the side mold 23 is fixed in contact with the outer periphery of the lower mold 24.

As shown in fig. 1, the ladle 5 has: a reservoir 52 formed in a bowl shape and capable of storing the molten metal 7 when the mold 2 is in an inverted state; and an opening/closing body 51 slidably fitted to the upper surface of the middle mold 22 of the mold 2 and provided with an injection port 53 alignable with the gate 8. The reservoir 52 has a heat insulating layer 54 on the inner surface to suppress a temperature drop of the molten metal 7. In the state where the molten metal 7 is stored in the reservoir 52, the molten metal 7 in the ladle 5 can be poured from the pouring port 53 into the gate 8 by tilting the mold 2 from the upside-down state to the upright state.

As shown in fig. 1 and 7, the opening/closing body 51 of the ladle 5 is connected to a connecting portion 11 extending from the opening/closing hydraulic crane 12, and the opening/closing body 51 is slid in the horizontal direction along the slide groove 10 of the center die 22 by the movement of the opening/closing hydraulic crane 12 to open and close the gate 8. As shown in fig. 1 and 9, the opening/closing body 51 has a plate shape and is formed with an injection port 53 that substantially penetrates in the vertical direction. The connecting portion 11 has a long cylindrical shape, one end of which is formed to be connectable to the hydraulic crane for opening and closing 12, and the other end of which is fixed to the opening and closing body 51. The coupling portion 11 is disposed between the upper mold 21 and the middle mold 22 and is slidable in the longitudinal direction.

When forming the molded article 9 using the tilting type gravity casting apparatus 1 configured as described above, as shown in fig. 2, first, a hydraulic crane, not shown, is controlled to hold the mold 2 in an inverted state. Here, the inverted state is a state in which the mold 2 is inclined so that the portion where the gate 8 is provided faces the side, and the gate 8 is kept below the product forming space 3. At this time, the opening/closing body 51 of the ladle 5 is kept in an open state in which the gate 8 is opened. Next, the molten metal 7 of the aluminum alloy controlled to the predetermined temperature is poured into the reservoir 52 of the ladle 5 by a ladle, not shown, and the molten metal 7 is stored.

Then, a tilting device, not shown, is controlled to gradually tilt the mold 2 to the standing state as shown in fig. 3. The molten metal 7 stored in the storage portion 52 of the ladle 5 is poured from the sprue 53 into the gate 8 and is poured into the product-forming space 3 through the runner 13. At this time, the pump 61 and the central portion pump 65 are driven to suck the air in the upper space 4 of the product forming space 3, thereby smoothing the flow of the molten metal. When the mold 2 is set upright, as shown in fig. 4, the molten metal 7 fills the product forming space 3.

Then, as shown in fig. 5, the opening/closing hydraulic crane 12 is controlled to slide the opening/closing body 51, and the gate 8 is closed by shifting the inlet 53 of the opening/closing body 51 from the gate 8. Then, high-pressure gas is introduced into the introduction flow path 63 by the pump 61, and supplied to the upper space 4 of the product forming space 3 through the supply flow path 64. Further, the center pump 65 supplies high-pressure gas to the hub hole forming portion 32. Then, a cooling unit, not shown, provided in the lower mold 24 is operated to cool the molten metal 7 in the product forming space 3, and the molten metal 7 is solidified.

When the molten metal 7 is cooled and solidified, a hydraulic crane, not shown, is controlled to move the upper mold 21 and the middle mold 22 upward and move the side molds 23 in 4 directions. Then, the molded article 9 is taken out from the lower mold 24 to obtain a product.

As described above, according to the tilting gravity casting apparatus 1 of the present embodiment, the molten metal 7 in the product-forming space 3 can be pressurized by supplying high-pressure gas, so that it is not necessary to provide a riser. Therefore, the casting time can be shortened to the time for cooling and solidifying the riser, and the production cost of the product can be reduced. In addition, the amount of molten metal used to form the riser, the melting cost, and the machining cost for cutting the riser can be reduced.

Further, since the ladle 5 is provided with the opening/closing body 51 slidably movable with respect to the mold 2, the structure for opening and closing the gate 8 can be simplified, and clogging with molten metal is less likely to occur. Further, since the length of the runner 13 can be shortened as compared with a case where a device for closing the runner is separately provided, a decrease in the temperature of the molten metal 7 can be suppressed, and temperature control of the molten metal 7 can be facilitated. Further, since the runner 13 is shortened, the molten metal 7 in the runner 13 can be suppressed from staying, and the amount of the molten metal 7 can be easily controlled.

Further, since the supply passage 64 supplies the gas to the upper space 4 of the product forming space 3 from the horizontal direction, the gas is not directly injected to the molten metal 7 stored in the product forming space 3, and the gas is not concentrated at one point by branching the supply passage 64 into a plurality of passages, so that the molten metal 7 can be effectively prevented from being dented by the injection of the gas.

The embodiments of the present invention are not limited to the above-described embodiments, and it goes without saying that the embodiments can be appropriately modified within a range not departing from the scope of the idea of the present invention.

Industrial applicability of the invention

The gravity casting apparatus 1 of the present invention is suitably used as a casting apparatus for casting a formed article of aluminum alloy, for example.

Description of the reference numerals

1 inclined gravity casting device

2 casting mould

3 product forming space

4 upper space

5 watering bucket

6 gas supply part

7 molten metal

8 pouring gate

9 shaped part

51 opening and closing body

52 reservoir portion

53 sprue

Claims (3)

1. A tilting gravity casting device is provided with:

a mold having a product forming space formed therein for forming a molded product, the mold receiving molten metal from a gate;

a ladle having a storage section capable of storing the molten metal and a plate-shaped opening/closing body that is in contact with the mold and has an inlet that is alignable with the gate; and

a gas supply part for supplying gas to the product forming space,

the above-described tilting gravity casting apparatus is characterized in that,

the opening/closing body is formed in a plate shape on a lower surface of the ladle, and the sprue for injecting the molten metal in the reservoir into the gate of the mold is formed on a surface abutting against the mold,

the opening/closing body of the ladle slides in a horizontal direction by the movement of the hydraulic crane for opening and closing, and the ladle slides, and further, the molten metal in the storage section can be poured from the pouring port of the opening/closing body into the pouring gate of the mold from the pouring port of the opening/closing body by aligning the pouring port of the opening/closing body with the pouring gate of the mold, and the pouring port of the opening/closing body is shifted from the pouring gate of the mold, so that the pouring gate of the mold is closed by the opening/closing body, or the pouring gate is opened from the closed state.

2. The inclined gravity casting apparatus of claim 1,

the gas supply unit has a gas flow path for supplying gas from the outside of the mold to the upper space of the product forming space,

the gas flow path is communicated with the upper space in a horizontal direction.

3. The inclined gravity casting apparatus of claim 2,

the gas flow path includes: an introduction flow path which communicates with the outside of the mold and introduces gas from the outside; and

and a supply passage which is branched from the introduction passage and supplies gas to an upper space of the product forming space.