JPH07506053A - Casting method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Casting method Technical field The present invention relates particularly, but not exclusively, to a method of casting thermoset materials, It concerns a method of casting genus.

Background technology In traditional metal casting methods, molten metal is introduced into the mold through one or multiple feed channels. A supply channel and an auxiliary vessel called a header are introduced into the casting cavity of the casting machine. When the metal in the cavity first cools and at least partially solidifies, the casting Provided to compensate for shrinkage of metal within the cavity.

metal in the feed channel and header before it fills the casting cavity, or At least the metal within the casting cavity first cools and at least partially solidifies To ensure that the supply does not cool too quickly to solidify before Should the shoulder and/or header have a volume of significant size in relation to the volume of the casting cavity? It is common practice to have a product. For example, the sum of feed channels and headers is essentially Designed to be the same volume as the upper casting cavity.

Careful mold design and cooling of the metal in several areas in the casting cavity inside the supply lines and headers by using cold air or other techniques such as The cooling rate of the molten metal can be controlled to a certain extent. Casting keys are used in some applications. A heating insert is used to maintain the temperature of the metal in the mold outside of the cavity. However, these are expensive and localized in the cavity associated with the insert burial area. It tends to heat up.

According to all such known metal casting techniques, heat melts the metal before introduction into the mold. The metal then solidifies in the feedline/header and is then discarded. be done. Also, the removal of the supply channel/header after finishing the final casting operation is especially important when removing the supply channel/header. / Will involve expensive machining if the volume of the header is large.

Disclosure of invention According to the invention, a casting cavity corresponding to the shape of the article to be cast, and Using a mold having a container cavity communicating with the casting cavity, thermosetting material is The present invention provides a method for casting an article by using a casting material. The method The molten thermoset material is introduced into the casting cavity and into the container cavity, and The casting material in the bit is first cooled and at least partially solidified, and It consists of applying heat from an external source to the material within the container cavity.

Therefore, a large volume is required to prevent premature cooling of the material in the feed channel or header. Since these dimensions are not required, these dimensions can be reduced to a minimum. Thus the supply line and The amount of casting material required for the header is minimized and therefore As a result, the amount of material required to be melted is significantly reduced compared to conventional casting methods. death Therefore, the casting method according to the invention greatly increases efficiency in terms of thermal energy. It is.

In addition, the casting casing is used to maintain the casting material in the feed path and header in a molten state. Since no heat is required from the molten material in the mold, the material is A brief explanation of the drawing that requires heating at a lower temperature overall. FIG. 1 is a sectional view showing a mold used in a conventional casting method.

FIG. 2 is a sectional view showing a mold used in the casting method according to the present invention.

FIG. 3 is a sectional view of a mold similar to FIG. 2 but showing a modified example.

BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIG. 1, a mold M is provided for casting metal, and the mold M is a sand mold. a casting cavity 1 which is present and has a shape corresponding to the article to be cast; There is. The molten metal is introduced into the mold M at the opening 5 and flows along the feed path 4 into the in-gauge. Flows through channel G into casting cavity 1.

Mold M includes a pair of auxiliary containers 2.3, also known as "headers".

When the metal in the casting cavity l solidifies, each container cavity header 2. 3 and feed channel 4 by drawing additional molten metal into the casting cavity l. A contraction occurs.

The molten metal is fed through the ingate G from the supply path 4 and the ingate Gl from the header 2. The surface force flows into the casting cavity l in a downward direction so as to open approximately vertically. F The header 3 is provided at the end of the supply path 4.

Normally, the volume of the headers 2, 3 and the feed channel 4 is such that the metal in the casting cavity l is initially The molten metal therein cools too quickly and before solidifying at least partially to ensure cooling and no solidification in the header 2.3 and feed channel 4. In this way the molten metal must be larger than the header 2 to cause shrinkage. , 3 and supply line 4.

Referring to FIG. 2, a mold M is provided, in which a supply channel 4 A feed channel 7 with a smaller volume is provided and again the head of the mold M of FIG. A single header 6 is provided which has a volume significantly smaller than that of either of the daphnes. It will be done.

Otherwise, mold M has a casting cavity la similar to mold M of FIG. The molten metal is introduced into the casting cavity la by injecting it into the opening 5a. The molten metal from the opening 5a flows along the supply road shoulder 7 via the ingate Ga to the casting cavity. Flows into Tila.

According to the invention, the molten metal in the casting cavity la is first cooled and at least Since the metal also partially solidifies, the molten metal in the supply channel 7 and the header 6 is not cast. The molten metal is heated by an external heating means.

Heating may be achieved in this example by passing electrical current through the metal between the molds. This causes the metal in the feed line 7 and header 6 to experience resistive heating.

In this example, the first electrode is designated 9A and the molten metal is cast. so that the electrode 9A is in electrical contact with the metal in the supply road shoulder 7 adjacent to the opening 5a. is placed in the mold Ml. The second electrode 9 is used when the molten metal is cast. Placed in the mold Ml4A so as to make electrical contact with the metal in the header 6, the electrical circuit Thus from the supply channel 7 through the metal in the casting cavity la to the header 6. . Since the volumes of the supply channel 7 and the header 6 are smaller than the volume of the casting cavity la, Therefore, the metal in the casting cavity la is not subjected to significant resistive heating effects.

Of course, the current is accommodated at least in the supply line 7 and preferably also in the header 6. A relatively small volume of metal resists the flow of electric current so as to produce a resistive heating effect It must be of sufficient size.

The electrodes 9, 9A are conveniently made of carbon and are connected by suitable cables 8. It is connected to a controller 10 which in turn is connected to a power source 11 .

The controller lO preferably carries a current and therefore controls the magnitude of the electrical heating power in the mold Ml. metal in feed channel 7 and header 6 operable and preferably to adjust the height; includes a timer so that the heating can be completely shut off after a predetermined period of time.

Preferably, the controller 1o controls the initial cooling and cooling of the metal in the casting cavity la. The current flowing through at least the partial solidification is applied immediately after the metal is cast, e.g. Depending on the nature of the article to be made, its size and the shape of the mold and mold Ml, or logarithmically or according to other cooling characteristics.

Figure 3 shows a modification of the mold M1 shown in Figure 2, similar parts having the same reference numerals. A number is given. In the arrangement shown in Figure 3, the opening 5a into which molten metal is injected is the casting key. There is a noticeable spacing above the top of the cavity la, i.e. during casting the casting cavity la are spaced apart by a distance H to increase the pressure of the molten metal within.

Various modifications may be made without departing from the scope of the invention.

Of course, the shape of the casting cavity la shown in the drawings is for illustration purposes only. It can actually consist of a complex shape that corresponds to the shape of the article to be cast. .

The casting cavity la uses a removable pattern of the article to be cast or utilize patterns assembled in the mold and lost during the casting process. It can be formed by

Mold Ml is a sand mold, but other molds suitable for the thermoset material to be cast in it. It is also possible to consist of mold material.

In the example described, the heating of the metal in the supply channel 7 and the header 6 is achieved by means of carbon electrodes 9. ．． This is accomplished by resistive heating utilizing 9A. The positions of electrodes 9 and 9A are appropriate. may be changed to The first electrode 9A is an opening 5a into which molten metal is injected. It is conceivable that it consists of a carbon rod inserted into the

While the metal in the casting cavity la is first cooled and at least partially solidified, other alternative means for heating the metal in the supply channel 7 and/or the header 6. It may be provided. For example, the heating may be resistive heating, or one or more advantageous positions. This can be achieved by induction heating with a positioned coil.

In the device shown in FIGS. 2 and 3, only a single header 6 is provided. However, in other devices, no header needs to be provided or one The above headers may be provided as desired.

In the apparatus described in connection with FIG. 2, the current flow path is in the casting cavity la. extends to metal. In other devices, the electrodes 9, 9A have a current flow path in the casting cavity l. may be arranged so as not to include the metal in a.

Although the invention has been described in connection with a method of casting metal, the invention When disposable molds or guicasting or injection molding of thermosetting plastic materials It can be applied to the casting of other thermosetting materials in permanent molds, such as in shapes.

in their special form or means for performing the disclosed functions; any method or process for obtaining the disclosed results, or any such substance or process as may be appropriate. The foregoing description, the claims below, expressed by grade or group of compositions. The features disclosed in the scope or the accompanying drawings may be In this combination, in its various forms, it may be used to realize the present invention. It can be done.

Danri 11--Yu +1.111, PCT/(J 93100913 Continuation of front page (51) Int, C1,6 identification symbol Internal office reference number B29C45/73 7 639-4F // B 29 K 101:10 (81) Designated countries EP (AT, BE, CH, DE.

DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE) , 0A (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, NE, SN.

TD, TG), AU, BB, BG, BR, CA, CZ.

FI, GB, HU, JP, KP, KR, LK, MG, MN, MW, No, NZ, PL, RO, RU, SD, SK, UA, US I

Claims (12)

[Claims] 1. a casting cap corresponding to the shape of the article to be cast, and the casting cap; In a thermoset material that utilizes a mold having a container capitivity that communicates with the A method of casting an article, the method comprising: applying a molten thermoset material to a casting cap; is introduced into the vessel cavity, the casting material in the casting cavity is first allowed to cool, and at least partially solidify, while applying heat from an external source to the material within the container capi A casting method characterized in that it consists of applying. 2. Said container capi- ty has a header and a header for introduction of molten material from outside the mold. molten material from the vessel capitivity to contract. , during the initial cooling and at least partial solidification of the casting material in said casting capacity; The casting method according to claim 1, wherein the casting method is performed by casting. 3. The container cavity is configured to transport the casting material from the container cavity to the casting cap. from the casting cavity so as to flow substantially upwardly or downwardly into the casting cavity. communicating with the casting cavity through an ingate that opens approximately perpendicularly to the pitey; The casting method according to claim 2, characterized in that: 4. Claims 1 to 3, wherein the thermosetting material is metal. The casting method according to any one of Item 3. 5. of sufficient magnitude that the heat is heated by the resistance of the metal in the vessel cavity. characterized in that the electric current is applied by passing the electric current through the metal in the container cavity; 4. The casting method according to claim 4. 6. When the molten material is cast, it is in electrical contact with the metal in the vessel cavity. a first electrode is placed in the mold, and when the molten material is cast, the first electrode a second electrode in electrical contact with the cast metal at a location spaced apart from the mold; from the first electrode through the metal in the container cavity. The casting according to claim 5, characterized in that a current path is provided to the second electrode. Construction method. 7. The mold has two container cavities, one directly connected to the casting cavity. a header that communicates with and that also communicates directly with said casting capacity and of said mold. a supply channel communicating with the outside and into which the molten metal is introduced; When the molten metal is cast, the first electrode is in electrical contact with the metal in the supply path. and when the metal is cast, the second electrode electrically connected to the metal in the header such that a flow path contains the metal in the casting cavity. Claim 6, characterized in that the second electrode is arranged so as to be in contact with the second electrode. The casting method described above. 8. The molten metal flows into the casting cavity and the vessel cavity by gravity. Any one of claims 1 to 7 characterized in that it is introduced. The casting method described in . 9. Claim 8, characterized in that the mold is made substantially of sand. casting method. 10. Claims characterized in that said mold is made of a substantially insulating material. The casting method according to any one of the above. 11. The amount of heating action of the heating means is such that the material in said casting capit y must first be cooled. Claims characterized in that the amount is reduced when at least partially solidified. The casting method according to any one of the above. 12. The heating action of the heating means reduces the amount of casting material in the casting capacity. Claims characterized in that they are completely removed upon at least partial solidification. The casting method according to any one of Items 1 to 11.