Source: https://insight.rpxcorp.com/pat/US10441998B2
Timestamp: 2020-07-13 11:28:33
Document Index: 455961067

Matched Legal Cases: ['art 13', 'art 14', 'art 14', 'art 14', 'art 13', 'art 114', 'art 13', 'art 14', 'art 13', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14']

Patent US 10,441,998 B2
1. A casting method for molding a product based on low-pressure casting by using a casting device in which a mold with a cavity is disposed over a holding furnace storing molten metal, comprising the steps of:
raising the molten metal to a vicinity of a gate of the cavity by increasing a pressure in the holding furnace and thereafter filling the cavity with the molten metal by decreasing a pressure in the cavity by suction and simultaneously further increasing pressure applied to the holding furnace to increase the pressure in the holding furnace;
stopping compression of the holding furnace when solidification of the molten metal is completed, andwherein in the step of filling the cavity with the molten metal by decreasing the pressure in the cavity by suction and simultaneously further increasing pressure applied to the holding furnace, the pressure of the holding furnace increases more rapidly than during the step of raising the molten metal to the vicinity of the gate of the cavity by increasing the pressure in the holding furnace.
Centrifugal method and apparatus for melting and casting of metal alloys
US 4,763,717 A
Pierre Lajoye
2. The casting method according to claim 1, further comprising the steps of:
stopping decompression of the cavity when the molten metal sensor detects completion of filling with the molten metal within the preset filling time.
3. The casting method of claim 1, further comprising:
providing a plurality of casting units, each comprising a holding furnace configured to store molten metal, a mold with a cavity and a compression part configured to increase a pressure in the holding furnace; and
providing a decompression part configured to decrease a pressure in the cavity of each of the plurality of casting units by suction,wherein the decompression part comprises a vacuum tank with a suction pipe at an inlet side and a discharge pipe at an outlet side, a vacuum pump connected to the discharge pipe of the vacuum tank, branch pipes that are branched from the suction pipe of the vacuum tank and are respectively communicated with the cavity of each of the plurality of casting units and on-off valves configured to open and close the respective branch pipes.
4. The casting method according to claim 3, wherein the cavity of the mold is a casting space configured for molding a suspension member of a car.
5. The casting method according to claim 3, wherein the cavity of the mold is a casting space configured for molding a cylinder head of an internal combustion engine.
6. The casting device method according to claim 3, wherein the cavity of the mold is a casting space configured for molding a motor case.
7. A casting method for molding a product based on low-pressure casting by using a casting device in which a mold with a cavity is disposed over a holding furnace storing molten metal, comprising the steps of:
stopping compression of the holding furnace when solidification of the molten metal is completed,wherein a first rate at which the pressure in the holding furnace increases during the step of raising the molten metal to the vicinity of the gate of the cavity is slower than a second rate at which the pressure in the holding furnace increases during the step of filling the cavity with the molten metal by decreasing the pressure in the cavity by suction and simultaneously further increasing pressure applied to the holding furnace.
8. The casting method according to claim 7, further comprising the steps of:
9. The casting method of claim 7, further comprising:
The casting device further includes a mold 9 between the movable table 6 and the fixed table 4 and a chamber 10 in which the mold 9 is air-tightly housed. The mold 9 includes an upper mold 9U fixed to the movable table 6 and a lower mold 9L fixed to the fixed table 4. They form a cavity 9C as a casting space between them. Further, a gate 11 is provided in the lower mold 9L, which is open to the lower part of the cavity 9C.
Then, the casting method continues with Step S2 where Compression 1 is started. Step S2 involves increasing the pressure in the holding furnace 5 with gas by the compression part 13 and thereby raising the molten metal M to the vicinity of the gate 11 of the cavity 9C. That is, Compression 1 in FIG. 4 is to apply such a pressure that raises the molten metal M to the vicinity of the gate 11 of the cavity 9C.
In the casting method and the casting device 1, the molten metal M is raised to the vicinity of the gate of the cavity 9C by increasing the pressure in the holding furnace 5, and thereafter the cavity 9C is filled with the molten metal M by decreasing the pressure in the cavity 9C and further increasing the pressure in the holding furnace 5. Therefore, the amount of suction by the decompression part 14 corresponds to the total volume of the inner space of the chamber 10 (excluding the space occupied by the mold 9) and the cavity 9C. That is, the decompression part 14 performs the minimum suction. Therefore, in the casting method and the casting device 1, a reduction in equipment cost and production cost can be achieved by employing a simple decompression part 14.
In particular, in the casting device 1, the cavity 9C of the mold 9 is a casting space for molding the suspension member SM of a car. Therefore, the above-described improvement in the molten metal run makes it possible to obtain the high quality suspension member SM.
As with the first embodiment, a casting method using the casting device 1 involves raising the molten metal M to the vicinity of the gate 11 of the cavity 9C by increasing the pressure in a holding furnace 5 with gas, and thereafter filling the cavity 9C with the molten metal M by decreasing the pressure in the cavity 9C by suction and further increasing the pressure in the holding furnace 5. The casting method further involves stopping the decompression of the cavity 9C when the molten metal sensor 16 detects completion of filling with the molten metal M within the preset filling time.
That is, in the casting unit 1 (Unit 1) shown on the left side of FIG. 8, the molten metal M is raised to the vicinity of the gate 11 of the cavity 9C by increasing the pressure in the holding furnace 5 with gas by the compression part 13. Then, the cavity 9C is filled with the molten metal M by opening the on-off valve 14E of the decompression part 114 so as to rapidly decrease the pressure in the cavity 9C by suction and further increasing the pressure in the holding furnace 5 by the compression part 13. After a preset predetermined filling time, the decompression of the cavity 9C is stopped by closing the on-off valve 14E of the decompression part 14. When solidification of the molten metal M is completed, the compression of the holding furnace 5 by the compression part 13 is stopped.
The casting device 1 having the above-described configuration is operated based on the previously-described casting method in which the molten metal M is raised to the vicinity of a gate by increasing the pressure in a holding furnace 5, and thereafter the cavity 9C is filled with the molten metal M by decreasing the pressure in the cavity 9C and further increasing the pressure in the holding furnace 5.
In the casting device 1, this allows employing a simple decompression part 14 as with the previously-described embodiments. A reduction in equipment cost and production cost is thereby achieved. Further, a reduction in casting cycle is also achieved. Furthermore, the casting device 1 is configured such that the decompression of the cavity 9C is stopped after a present filling time. That is, the decompression part 14 is turned off before gas is produced from the cores N1 to N3. This can prevent decompression part 14 from being contaminated by gas from the cores N1 to N3.
Furthermore, the casting device 1 is configured such that after the molten metal M is raised to the vicinity of the gate 11, the cavity 9C is filled with the molten metal M by the rapidly decreasing the pressure in the cavity 9C and further increasing the pressure in the holding furnace 5. Therefore, the molten metal M can run in the cavity 9C very well. In particular, the casting device 1 includes the mold 9 with the cavity 9C that is a casting space for molding a cylinder head of an internal combustion engine. Therefore, the above-described improvement in the molten metal run allows obtaining a high quality cylinder head.
In the casting device 1, this allows employing a simple decompression part 14 as with the previously-described embodiments. A reduction in equipment cost and production cost is thereby achieved. Further, a reduction in casting cycle time is also achieved. Further, the casting device 1 is configured such that the decompression of the cavity 9C is stopped after a preset filling time. That is, the decompression part 14 is turned off before gas is produced from the cores N4. This can prevent the decompression part 14 from being contaminated by the gas from the cores N4.
Furthermore, the casting device 1 is configured such that after the molten metal M is raised to the vicinity of the gate 11, the cavity 9C is filled with the molten metal M by rapidly decreasing the pressure in the cavity 9C and further increasing the pressure in the holding furnace 5. Therefore, the molten metal M can run in the cavity 9C very well. In particular, in the casting device 1, the cavity 9C of the mold 9 is a casting space for molding a motor case, the above-described improvement of the molten metal run allows obtaining the high quality motor case.
Ota, Shunsuke, Masuta, Tatsuya
164457, 164254, 164255, 164256, 164257, 164258, 164 61, 164 63, 164 65, 164119, 164306