Pressure casting apparatus

Abstract

To explain a pressure casting apparatus capable of efficiently producing a large-sized casting excellent in quality.SOLUTION: A pressure casting apparatus comprises: a plurality of holding chambers configured to reserve a melt of metal melted; a metal mold including at least one metal-mold cavity for forming a casting; at least one gas pressurizing unit configured to pressurize a melt from the plurality of holding chambers by gas pressure and thereby feed the melt into the at least one metal-mold cavity; and at least one working-fluid pressurizing unit configured to pressurize the melt fed into the at least one metal-mold cavity by working-fluid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to pressure casting apparatus. [Background technology]

[0002] Patent Document 1 discloses a casting apparatus including a holding furnace configured to accommodate molten metal, a mold including a mold cavity, and a supply mechanism configured to supply molten metal introduced from the holding furnace into a pressurized chamber into the mold cavity by gas pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 176623 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure describes a pressure casting apparatus capable of efficiently producing large quality castings. [Means for solving the problem]

[0005] An example of a pressure casting apparatus includes a plurality of holding chambers configured to store molten metal, a mold including at least one mold cavity for forming a casting, at least one gas pressurizing unit configured to pressurize the molten metal from the plurality of holding chambers with gas pressure and supply the molten metal into the at least one mold cavity, and at least one hydraulic oil pressurizing unit configured to pressurize the molten metal supplied into the at least one mold cavity with hydraulic oil. [Effects of the Invention]

[0006] The pressure casting apparatus according to the present disclosure makes it possible to efficiently produce large, high-quality castings. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a top view schematically showing an example of a pressure casting apparatus. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a top view schematically showing another example of a pressure casting apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and redundant explanations will be omitted. Note that in this specification, when referring to the top, bottom, right, and left of a figure, the directions of the reference numerals in the figure will be used as the reference.

[0009] A pressure casting apparatus 1 will be described with reference to Figures 1 and 2. The pressure casting apparatus 1 is a vertical casting apparatus used, for example, for low-pressure or low-to-medium pressure casting. As illustrated in Figures 1 and 2, the pressure casting apparatus 1 includes a plurality of holding furnaces 10, a fixed platen 20, a movable platen 30, a mold 40, a plurality of gas pressurizing units 50, a plurality of hydraulic oil pressurizing units 60, and a control unit (not shown) configured to control these.

[0010] The pressure casting apparatus 1 illustrated in Figures 1 and 2 includes two holding furnaces 10A and 10B as the multiple holding furnaces 10. The holding furnaces 10A and 10B are detachably attached to a stationary platen 20. In the examples of Figures 1 and 2, the holding furnaces 10A and 10B have substantially the same configuration. Therefore, the following description will focus on the holding furnace 10A, and a description of the holding furnace 10B will be omitted.

[0011] The pressure casting apparatus 1 illustrated in Figures 1 and 2 includes two gas pressurizing units 50A and 50B as the multiple gas pressurizing units 50. In the example of Figures 1 and 2, the gas pressurizing units 50A and 50B have substantially the same configuration. Therefore, the following description will focus on the gas pressurizing unit 50A (first gas pressurizing unit), and a description of the gas pressurizing unit 50B (second gas pressurizing unit) will be omitted.

[0012] The pressure casting apparatus 1 illustrated in Figures 1 and 2 includes two hydraulic oil pressurizing sections 60A, 60B as the multiple hydraulic oil pressurizing sections 60. In the example of Figures 1 and 2, the hydraulic oil pressurizing sections 60A, 60B have substantially the same configuration. Therefore, the following description will focus on the hydraulic oil pressurizing section 60A, and a description of the hydraulic oil pressurizing section 60B will be omitted.

[0013] The holding furnace 10A includes a holding chamber 11, a pressurizing chamber 12, a pouring chamber 13, a connecting flow path 14, and an opening / closing section 15. The holding chamber 11, the pressurizing chamber 12, and the pouring chamber 13 may be arranged, for example, in a line in the horizontal direction in this order.

[0014] The holding chamber 11 is configured to store the molten metal M. The molten metal M is a liquid metal formed by melting a metal (such as aluminum) by heat. An opening 11a connected to the connecting flow path 14 is provided at the bottom of the holding chamber 11.

[0015] The pressurizing chamber 12 and the pouring chamber 13 are configured to contain the molten metal M supplied from the holding chamber 11 through a connecting flow path 14. The pressurizing chamber 12 includes an opening 12a that is open at the top. The opening 12a is closed by a lid member 16 that seals a space V above the surface of the molten metal M within the pressurizing chamber 12. The pouring chamber 13 is located below the mold 40 and the hydraulic oil pressurizing section 60A.

[0016] The connecting flow path 14 extends below the holding chamber 11, the pressurizing chamber 12, and the pouring chamber 13 so as to connect the bottom of the holding chamber 11, the bottom of the pressurizing chamber 12, and the bottom of the pouring chamber 13. A heating unit (e.g., an electric heater) configured to heat the molten metal M in the holding furnace 10A may be disposed in the connecting flow path 14.

[0017] The opening / closing unit 15 is, for example, a rod-shaped member that is movable in the vertical direction. The opening / closing unit 15 may be configured so that its tip can be inserted into and removed from the opening 11a of the holding chamber 11. When the tip of the opening / closing unit 15 closes the opening 11a, the molten metal M in the holding chamber 11 does not flow into the connecting flow path 14. On the other hand, when the tip of the opening / closing unit 15 is spaced upward from the opening 11a, the molten metal M in the holding chamber 11 is supplied to the pressurizing chamber 12 and the pouring chamber 13 via the connecting flow path 14. The opening / closing unit 15 is controlled by a control unit (not shown) to open the opening 11a and replenish the pressurizing chamber 12 and the pouring chamber 13 with molten metal M when the molten metal M in the pressurizing chamber 12 and the pouring chamber 13 is consumed by the casting of a casting.

[0018] The movable platen 30 is disposed above the fixed platen 20. The movable platen 30 is configured to be movable in the up and down direction relative to the fixed platen 20. The movable platen 30 may be provided with, for example, a plurality of through holes into which a plurality of guide posts (not shown) extending in the up and down direction from the fixed platen 20 can be inserted, respectively. The movable platen 30 may be configured to be movable in the up and down direction along the plurality of guide posts by inserting the corresponding guide posts into each of the through holes.

[0019] As shown in FIG. 2, the mold 40 is disposed between the fixed platen 20 and the movable platen 30. The mold 40 includes a lower mold 41 and an upper mold 42. The lower mold 41 is fixed to the upper surface of the fixed platen 20. A recess 41a that is recessed downward is provided on the upper side of the lower mold 41. The lower mold 41 is provided with a through-hole 41b that passes through the lower mold 41 from the bottom surface of the recess 41a to the lower surface of the lower mold 41. The opening at the bottom of the through-hole 41b communicates with the opening at the top end of the pouring chamber 13.

[0020] The upper die 42 is fixed to the lower surface of the movable platen 30. The lower side of the upper die 42 is provided with a convex portion 42a that protrudes downward.

[0021] 2, when the lower mold 41 and the upper mold 42 are mated so that the convex portion 42a of the upper mold 42 is positioned in the concave portion 41a of the lower mold 41, one mold cavity C is formed between the concave portion 41a and the convex portion 42a. The mold cavity C is a space having a shape corresponding to the casting product, and communicates with the opening at the upper end of the through hole 41b.

[0022] The gas pressurizing unit 50A includes a supply source 51, a pipe 52, and a molten metal level detection rod 53. The supply source 51 is configured to store an inert gas such as nitrogen gas. The pipe 52 passes through the lid member 16 and communicates with the space V from the supply source 51. The molten metal level detection rod 53 is attached to the lid member 16 so as to pass through the lid member 16 and extend vertically from the outside of the lid member 16 toward the surface of the molten metal M in the pressurizing chamber 12. The molten metal level detection rod 53 is configured to detect whether the surface of the molten metal M in the pressurizing chamber 12 has reached a predetermined height (predetermined level) when the molten metal M is supplied from the holding chamber 11 to the pressurizing chamber 12.

[0023] The gas pressurizing unit 50 is configured to pressurize the molten metal M in the pressurizing chamber 12 by the gas pressure of the inert gas supplied to the space V, thereby supplying the molten metal M in the pouring chamber 13 of the holding furnace 10A into the mold cavity C through the through-hole 41b. As described above, the gas pressurizing unit 50B is configured similarly to the gas pressurizing unit 50A. That is, the gas pressurizing unit 50B is configured to supply the molten metal M in the pouring chamber 13 of the holding furnace 10B into the mold cavity C. Therefore, the molten metal M in the pouring chamber 13 of the holding furnace 10A and the molten metal M in the pouring chamber 13 of the holding furnace 10B are each supplied to the space that constitutes one mold cavity C.

[0024] The hydraulic oil pressurizing part 60A extends so as to penetrate the movable platen 30 and the upper die 42. The hydraulic oil pressurizing part 60A is configured to pressurize the molten metal M in the die cavity C with hydraulic oil. The hydraulic oil pressurizing part 60A includes a pressurizing pin 61.

[0025] The pressure pin 61 is configured to be movable up and down by hydraulic pressure from a hydraulic pressure supply source (not shown). The pressure pin 61 includes a lower end 61a that is tapered downward. The lower end 61a may be conical.

[0026] In the hydraulic oil pressurizing unit 60A having the above configuration, when the pressurizing pin 61 is lowered by hydraulic pressure from the hydraulic pressure supply source, the pressurizing pin 61 presses the molten metal M in the mold cavity C. When the pressurizing pin 61 is lowered further, the lower end 61a closes the opening at the upper end of the through hole 41b. As a result, a pressure greater than the gas pressure acting on the molten metal M by the gas pressurizing unit 50 acts on the molten metal M in the mold cavity C. As a result, a casting with a densified cast structure is obtained.

[0027] [Effect] According to the above example, the molten metal M is supplied into the mold cavity C from each holding chamber 11 of the holding furnaces 10A, 10B. This increases the amount and speed of the molten metal M supplied into the mold cavity C. This effectively fills the mold cavity C with the molten metal M, and by operating the pressure pin 61 of the hydraulic oil pressure unit 60A at an appropriate timing, a high-strength casting with a denser cast structure can be obtained. As a result, it becomes possible to efficiently manufacture high-quality castings.

[0028] In the above example, the pressure casting apparatus 1 is equipped with two gas pressurizing units 50A, 50B. In this case, the molten metal M from each holding chamber 11 of the holding furnaces 10A, 10B is pressurized by the different gas pressurizing units 50A, 50B. As a result, the molten metal M from each holding chamber 11 of the holding furnaces 10A, 10B is supplied into the mold cavity C at sufficient pressure. This allows the molten metal M to be filled into the mold cavity C more effectively, making it possible to more efficiently produce higher quality castings.

[0029] According to the above example, one mold cavity C is formed by mating the lower mold 41 and the upper mold 42. In this case, the molten metal M is supplied into one mold cavity C at an increased supply amount and supply speed. Therefore, even if one mold cavity C is a large-capacity mold cavity for a large product, it is possible to efficiently manufacture a high-quality casting.

[0030] [Variations] The disclosure in this specification should be considered to be illustrative in all respects and not restrictive. Various omissions, substitutions, modifications, etc. may be made to the above examples without departing from the scope and spirit of the claims.

[0031] (1) As shown in Fig. 3, the pressure casting apparatus 1 may include a single gas pressurizing unit 50. The pressure casting apparatus 1 may include a single pressurizing chamber 12. The connecting flow path 14 may include a first flow path that joins the holding chambers 11 of the holding furnaces 10A, 10B with the pressurizing chamber 12, and a second flow path that branches off from the pressurizing chamber 12 to the pouring chambers 13 of the holding furnaces 10A, 10B. In this case, the molten metal M from each holding chamber 11 of the holding furnaces 10A, 10B is supplied to each pouring chamber 13 of the holding furnaces 10A, 10B by a single gas pressurizing unit 50. In this case, the same effects as those of the example shown in Figs. 1 and 2 can be obtained.

[0032] (2) The pressure casting apparatus 1 may include at least one gas pressurizing unit 50. That is, the pressure casting apparatus 1 includes two gas pressurizing units 50 in the examples of Figures 1 and 2, and two gas pressurizing units 50 in the example of Figure 3, but is not limited thereto, and may include three or more gas pressurizing units 50.

[0033] (3) The pressure casting apparatus 1 may include at least one hydraulic oil pressurizing unit 60. That is, although the pressure casting apparatus 1 includes two hydraulic oil pressurizing units 60 in the example of Figures 1 to 3, the present invention is not limited to this and may include one hydraulic oil pressurizing unit 60, or three or more hydraulic oil pressurizing units 60.

[0034] (4) In the example of Figures 1 to 3, the mold 40 includes one mold cavity C, but this is not limited thereto, and at least one mold cavity C may be formed by mating the lower mold 41 with the upper mold 42. When multiple mold cavities C are formed by mating the lower mold 41 with the upper mold 42, the mold cavities C may be connected to each other by runners (grooves formed in the lower mold 41 and / or the upper mold 42).

[0035] (5) The pressure casting apparatus 1 may further include a partial pressure pin. The partial pressure pin may be built into the mold 40. The partial pressure pin may be rod-shaped and configured to be able to move back and forth in the vertical direction by a drive mechanism (not shown). The partial pressure pin 70 may be configured to descend as necessary with the lower end 61a of the pressure pin 61 closing the through hole 41b, to apply a local pressure force to the molten metal in the mold cavity C. The partial pressure pin may be configured, for example, to use its lower end to press against the molten metal M in a thick-walled portion (not shown) in the mold cavity C where solidification is delayed.

[0036] [Other examples] Example 1. One example of a pressure casting apparatus includes a plurality of holding chambers configured to store molten metal; a mold including at least one mold cavity for forming a casting; at least one gas pressurizing unit configured to pressurize the molten metal from the plurality of holding chambers with gas pressure and supply the molten metal into the at least one mold cavity; and at least one hydraulic oil pressurizing unit configured to pressurize the molten metal supplied into the at least one mold cavity with hydraulic oil. In this case, the molten metal is supplied from the plurality of holding chambers into the at least one mold cavity. This increases the amount and speed of the molten metal supplied into the at least one mold cavity. Therefore, the at least one mold cavity is effectively filled with the molten metal, and by operating the at least one hydraulic oil pressurizing unit at the appropriate time, a casting with a more dense cast structure and high strength can be obtained. As a result, it becomes possible to efficiently produce large, high-quality castings.

[0037] Example 2. In the pressure casting apparatus of Example 1, the multiple holding chambers may include a first holding chamber and a second holding chamber, and the at least one gas pressurizing unit may include a first gas pressurizing unit configured to supply molten metal, which is replenished from the first holding chamber to the first pressurizing chamber for each casting, by gas pressure into at least one mold cavity, and a second gas pressurizing unit configured to supply molten metal, which is replenished from the second holding chamber to the second pressurizing chamber for each casting, by gas pressure into at least one mold cavity. In this case, the molten metal from the first and second storage chambers is pressurized by different first and second gas pressurizing units, respectively. Therefore, the molten metal from the first and second storage chambers is supplied into at least one mold cavity with sufficient pressure. This allows the molten metal to be more effectively filled into at least one mold cavity, making it possible to more efficiently produce large-scale castings with higher quality.

[0038] Example 3: In the pressure casting apparatus of Example 1 or Example 2, the at least one hydraulic oil pressurizing unit may include a plurality of hydraulic oil pressurizing units configured to pressurize the molten metal supplied into at least one mold cavity with hydraulic oil. In this case, the molten metal supplied into at least one mold cavity is pressurized by the plurality of hydraulic oil pressurizing units. This results in a casting with a more densified cast structure, making it possible to more efficiently produce larger castings with better quality.

[0039] Example 4: In the pressure casting apparatus of any of Examples 1 to 3, the at least one mold cavity may include a single mold cavity. In this case, as described in Example 1, molten metal is supplied into the single mold cavity at an increased supply amount and supply rate. Therefore, even if the single mold cavity is a large-capacity mold cavity for large products, it is possible to efficiently produce large, high-quality cast products. [Explanation of symbols]

[0040] 1...pressure casting apparatus, 10, 10A, 10B...holding furnace, 11...holding chamber (first and second holding chamber), 40...mold, 50...gas pressurization section, 50A...gas pressurization section (first gas pressurization section), 50B...gas pressurization section (second gas pressurization section), 60...hydraulic oil pressurization section, C...mold cavity, M...molten metal.

Claims

1. a plurality of holding chambers configured to store molten metal; a mold including at least one mold cavity for forming a casting; at least one gas pressurizing unit configured to pressurize the molten metal from the plurality of holding chambers with gas pressure to supply the molten metal into the at least one mold cavity; and at least one hydraulic oil pressurizing unit configured to pressurize the molten metal supplied into the at least one mold cavity with hydraulic oil.

2. the plurality of holding chambers include a first holding chamber and a second holding chamber; The at least one gas pressurizing unit is a first gas pressurizing unit configured to pressurize, by gas pressure, the molten metal replenished from the first holding chamber to the first pressurizing chamber for each casting, thereby supplying the molten metal into the mold cavity; 2. The pressure casting apparatus according to claim 1, further comprising: a second gas pressurizing unit configured to pressurize the molten metal replenished from the second holding chamber to the second pressurizing chamber for each casting by gas pressure, thereby supplying the molten metal into the mold cavity.

3. 2. The pressure casting apparatus according to claim 1, wherein the at least one hydraulic oil pressurizing unit includes a plurality of hydraulic oil pressurizing units configured to pressurize the molten metal supplied into the at least one mold cavity with hydraulic oil.

4. The pressure casting apparatus of any one of claims 1 to 3, wherein the at least one mold cavity comprises one mold cavity.

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