JP4883403B2 - Casting method for casting products - Google Patents

Description

The present invention relates to a casting method of a cast product, a lower mold storage mechanism used in the method, and a casting press apparatus. More specifically, a casting method for casting a cast product and a method for casting the cast product by superimposing an upper mold on a lower mold into which a predetermined amount of molten metal necessary for casting the cast product is poured. The present invention relates to a lower mold storage mechanism and a casting press apparatus.

Conventionally, in the production of casting by casting molten metal into a cavity defined by a mold formed by superposing the upper mold and the lower mold, the flow of the molten metal is controlled and the entrapment of impurities and gas is prevented. For the purpose of preventing the occurrence of defects and obtaining good products, it has been customarily indispensable to provide a flow path for molten metal that is not related to the product shape, which is called a casting method (for example, non-patent literature) 1).

Therefore, as a method for increasing the yield of castings, it is a main mold formed by various mold making methods, and does not have a cavity necessary for achieving a casting method, but has only a cavity necessary for casting product casting. Protrusion that is a main mold formed by various mold forming methods and does not have a cavity necessary for achieving a casting method, and can define a cavity for casting product casting with the cavity of the lower mold A casting method using an upper mold having a portion, wherein a molten metal in an amount necessary for casting only the casting product is injected into a cavity of the lower mold, and then a protruding portion of the upper mold. Casting method in which the upper mold is overlaid on the lower mold so as to define a cavity necessary for casting only the casting product by entering the cavity of the molten metal injection Sand press casting process) has been proposed (see Patent Document 1). In the casting method, a desired casting product can be easily and reliably cast in a situation where the yield of molten metal is high.

Illustrated by the Japan Foundry Engineering Society Casting Dictionary 1st edition Published in Japan Published by Nikkan Kogyo Shimbun November 30, 1995 Page 212 JP 2005-52871 A

However, in the casting method, since the surface of the molten metal injected into the lower mold is in an oxidizing atmosphere until the upper mold and the lower mold are matched, an oxide film is generated and the product is formed as an oxide-based casting defect. May remain. For this reason, it is desired to obtain a good casting product using this casting method.

Therefore, in view of the above circumstances, the present invention is used for a casting product casting method capable of suppressing the formation of an oxide film in the manufacture of a casting product and reducing oxide-based casting defects, and the method. It is an object of the present invention to provide a lower mold storage mechanism and a casting press device.

Also, the casting method of casting products of the present invention includes a lower mold having a concave portion of the product profile, by superimposing on the lower mold, the product contours to define a cavity for casting the casting product A casting method for casting a cast product using a mold including an upper mold having a bulging portion, the step of installing the lower mold in a bottomed gas injection box, and an atmospheric gas in the gas injection box A step of pouring a predetermined amount of molten metal necessary for casting a casting product into the concave portion of the lower mold during the injection of the atmospheric gas, and the upper mold toward the lower mold. And a step of ending the injection of the atmospheric gas during the period from the start of pouring until the upper mold is superimposed on the lower mold, and a step of stopping the lowering of the upper mold. There Ru.

According to the present invention, since the formation of a molten metal oxide film is suppressed, oxide-based casting defects are reduced, and a high-quality casting product can be cast.

The casting product casting method of the present invention includes a lower mold having a concave portion having a product contour shape into which a predetermined amount of molten metal necessary for casting a cast product is poured, and overlapping the lower mold. A mold composed of an upper mold having a bulging portion of a product contour shape that defines a cavity for casting a cast product, and a lower mold storage mechanism that suppresses an oxide film in casting production are used. The lower mold and the upper mold can be appropriately molded using various mold molding methods such as a green mold, a shell mold, a cold box mold, and a self-hardening mold. The present invention is also used for a mold containing a core. The mold of the present invention includes a porous mold. Furthermore, the mold molding method is not limited to squeeze, blow squeeze, air pressure molding method, or a combination thereof, but can also be a molding method such as cutting or pouring. In addition, the said casting product removed casting methods, such as pouring systems, such as pouring gates, raising, and degassing, from the general casting raw material taken out from the casting_mold | template after a frame opening, for example It is a thing that is attached to the machine as a final part or sold separately, such as a circular brake drum or a square case. The molten metal refers to a material in which iron or non-ferrous metal is dissolved and can be injected into the lower mold.

Hereinafter, based on an accompanying drawing, a casting method of a casting product of the present invention, a lower mold storage mechanism used in the method, and a casting press apparatus will be described.
As shown in FIG. 1 and FIG. 3, the casting press A used in an embodiment of the present invention is disposed to face a ladle tilting type pouring machine P along a molding line. . This casting press apparatus A includes a movable frame 1 connected to a traveling carriage (not shown) that reciprocates in the lateral direction (left and right direction in FIG. 1), and an elevating means B provided on the movable frame 1. The mold pressing plate 3 connected to the tip 2a of the rod 2 of the lifting / lowering means B, the guide rods 4 standing at the four corners of the mold pressing plate 3, and the upper mold F1 are connected to the mold pressing plate 3 of the mold pressing plate 3. The operation of, for example, four clamp means C supported from two opposite sides of the side, the lower mold storage mechanism D that suppresses an oxide film in casting production, the movable frame 1, the lifting means B, and the clamp means C are operated. Control means for controlling. The control means includes an operating circuit for reciprocating movement of the traveling carriage, an ascending / descending speed as an elevating operation of the elevating means B, an operating circuit for controlling the stop, an operating circuit for the clamping means C, and these operating circuits. It consists of a circuit that controls.

The lifting means B is not particularly limited in the present invention as long as the rod 2 can be lifted and lowered by an electric type, a hydraulic type or a pneumatic type. In the embodiment, the position and speed can be controlled with high accuracy. An electric servo cylinder is used. This electric servo cylinder incorporates a screw mechanism, a drive motor, a rotary encoder as a position detector, and the like. Instead of the electric servo cylinder capable of controlling the position and speed, an electric servo cylinder capable of controlling the speed and a linear scale can be used for detecting the position and controlling the positioning.

The clamping means C is not particularly limited as long as it can support the upper mold F1 on the mold pressure plate 3, but for example, a drive mechanism such as an air cylinder and the operation of the drive mechanism. It can comprise from the crank member which rotates or expands-contracts by. Alternatively, a support structure using an electromagnetic force or a support structure using an attractive force can be used.

The lower mold storage mechanism D includes a gas injection box 11 in which the lower mold F2 is installed, a gas blowing means E for injecting atmospheric gas into the gas injection box 11, and the gas injection box 11 and the gas blowing means E. A connecting body G to be connected is provided. The gas injection box 11 has an opening 12 through which the upper mold F1 can be inserted in the upper part, and a ring-shaped reinforcing material 13 in which a vent hole 13a is formed in the lower part (bottom part) and a vent hole in which a vent hole 14a is formed. It has a bottomed shape in which a wind box 15 is formed by placing the plate 14 thereon. The air box 15 can uniformly inject the atmosphere gas around and inside the lower mold F2. In addition, an attachment that can detachably fit the adapter 16 in the hose 17 that is connected to the gas blowing means E and that is connected to the adapter 16 at the other end, which constitutes the connecting body G, is formed on the side wall portion. 18 is provided. The gas blowing means E is not particularly limited. For example, an atmospheric gas supply device made of an inert gas such as a gas cylinder 19 can be used. As this inert gas, helium (He) gas, Ar (argon) gas, N2 (nitrogen) gas, or the like is used. The atmospheric gas supplied from the gas cylinder 19 is injected into the wind box 15 in the gas injection box 11, and then circulates through the vent holes 13a and 14a around the lower mold F2 and through the lower mold F2. Filled.

Hereinafter, the pressing process in the present embodiment will be described. First, as a mold, a main mold formed by a green molding method in a casting frame 22 using raw sand 21, and a product into which a predetermined amount of molten metal 23 required for casting a cast product is injected. A lower mold F2 having a contour-shaped concave portion 24 and a main mold formed by a green molding method in a casting frame 32 using green sand 31, and a product defining a cavity for casting the cast product A casting mold comprising an upper casting mold F1 having a contoured bulging portion 33 is used.

Next, as shown in FIG. 1, after molding, the upper mold F1 in the inverted state conveyed by the conveyor, for example, the roller conveyor 51, is added to the casting press apparatus A waiting on the molding line. After the pressure plate 3 is lowered and supported by the mold pressing plate 3 by the clamping means C, it moves from the molding line to the retracted position and stands by. Then, the lower mold F2 set in the gas injection box 11 that has been transported subsequently inserts the rod of the positioning cylinder 53 through the openings formed at the four corners of the surface plate 52 on which the box 11 is placed, It is fixed at the pouring position.

Next, as shown in FIG. 2, after connecting the adapter 16 to the attachment 18, for example, an inert gas is passed from the gas cylinder 19 through the air box 15 in the gas injection box 11 through the vent hole 14 a which is a blowing port. 11 is filled with an inert gas. This inert gas blowing amount is filled before the next molten metal 23 is injected.

Next, as shown in FIG. 3, the pouring machine P waiting at a position away from the molding line is moved to the lower mold F2 side, the ladle 54 is tilted, and a cavity is formed in the recess 24 of the lower mold F2. Molten metal 23 in a range of 120% of the volume is poured. As a result, when the molten metal 23 is injected, the molten metal 23 is held in an inert gas atmosphere, so that generation of an oxide film is suppressed.
Then, after pouring is completed, the pouring machine P is moved backward so that the casting press apparatus A is positioned so that the upper mold F1 comes to a position above the lower mold F2, as shown in FIGS. Move.

Next, as shown in FIG. 4, the upper mold F1 is allowed to enter the molten metal 23 poured into the lower mold F2. Then, the upper mold F1 overlaps the lower mold F2 and starts to contact, and the lowering of the upper mold F1 is stopped at a position where the mold is not pushed too much. When the upper mold F1 begins to overlap the lower mold F2, the blowing of the inert gas is stopped, and then the connection between the adapter 16 and the attachment 18 is released. Thereby, since the molten metal 23 is maintained in the atmosphere of the inert gas even in the process in which the upper mold F1 is superimposed on the lower mold F2, the generation of an oxide film is suppressed.

In the present embodiment, the lower mold F2 is set in the gas injection box 11, filled with an inert gas such as Ar, N2, etc., and the gas injection box 11 is filled with an inert gas atmosphere. Then, the upper mold F1 is quickly lowered and the upper mold F1 is superposed on the lower mold F2, thereby suppressing the oxidation of the molten metal 23. As a result, oxide-based casting defects in the cast product can be reduced. The inert gas is preferably blown before the molten metal 23 is injected until the upper mold F1 is aligned with the lower mold F2. However, the present invention is not limited to this. The formation of an oxide film can also be suppressed by blowing before the injection of the metal 23 or blowing from the injection of the molten metal 23 to the end of pouring.

1 is a schematic configuration diagram of a casting press apparatus according to an embodiment of the present invention. It is a figure which shows a gas injection process. It is a figure which shows the pouring process during gas injection | pouring. It is a figure which shows the state which descend | falls an upper casting_mold | template and superimposes on a lower casting_mold | template during gas injection | pouring.

A Casting press B B Elevating means C Clamping means D Lower mold storage mechanism E Gas blowing means G Connecting body P Pouring machine F1 Upper mold F2 Lower mold 1 Movable frame 2 Rod 2a Tip 3 Mold pressure plate 4 Guide rod 11 Gas Injection box 12 Opening portion 13 Reinforcing material 14 Ventilation plate 14a Ventilation hole 15 Air box 16 Adapter 17 Hose 18 Attachment 19 Gas cylinder 21, 31 Fresh sand 22, 32 Cast frame 23 Molten metal 24 Recess 33 Swelling portion 51 Roller conveyor 52 Surface plate 53 Positioning cylinder 54 Tribe

Claims (1)

Using a mold comprising: a lower mold having a product contour-shaped concave portion; and an upper mold having a product contour-shaped bulging portion that defines a cavity for casting the cast product by being superimposed on the lower mold A casting method for casting a cast product,
Installing the lower mold in a bottomed gas injection box;
Injecting atmospheric gas into the gas injection box;
A step of pouring a predetermined amount of molten metal necessary for casting a cast product in the recess of the lower mold during the injection of the atmospheric gas;
Lowering the upper mold toward the lower mold;
A step of ending the injection of the atmospheric gas from the start of pouring until the upper mold is superimposed on the lower mold;
A method of casting a casting product, the method including a step of stopping the lowering of the upper mold.