Method and apparatus for casting components

Abstract

Method for casting components from a magnesium alloy, comprising the following steps: Providing a semi-finished product (10) made of a magnesium alloy; Melting the semi-finished product to a melt (13) in a metering furnace (11); Discharge of the melt from the metering furnace (11) by means of a metering pump (16) via a trough (15) and filling of the melt via the trough (15) into a sand casting mold (14), wherein the fill level of the melt in a filling area (19) of the sand casting mold (14) is monitored and the delivery rate of the metering pump (16) is regulated depending on this; Solidification of the molten metal in the sand mold (14) and removal of the component from the sand mold.

Description

[0001] The invention relates to a method and a device for casting components made of a magnesium alloy.

[0002] In practice, it is generally known to produce components from magnesium alloys by casting. For this purpose, a semi-finished product made of a magnesium alloy is melted in a dosing furnace. The melt is withdrawn from a melting chamber of the dosing furnace using a dosing pump and fed into a chamber of a cold-chamber die-casting machine. The melt solidifies in the casting mold to form the component to be produced. In practice, the casting molds are die-casting molds. Therefore, to date, it has only been known to produce components from a magnesium alloy using a dosing furnace system via a die-casting process.

[0003] Based on this, the invention is based on the object of creating a novel method and a novel device for casting components made of a magnesium alloy.

[0004] This object is achieved according to a first aspect by a method according to claim 1.

[0005] The filling level of the melt in a filling area of ​​a sand casting mold is then monitored and the delivery rate of the dosing pump is regulated depending on this.

[0006] According to a second aspect, this object is achieved by a method according to claim 6.

[0007] According to this, a filling area of ​​a sand casting mold is gassed with protective gas while the melt is being poured into the sand casting mold.

[0008] Both the first aspect of the invention and the second aspect of the invention, which are preferably used in combination with one another, relate to the production of components from a magnesium alloy by casting using sand casting molds. According to the first aspect of the invention, the filling area of ​​the sand casting mold is monitored in order to detect the fill level of the melt in the filling area and, depending on this, to regulate the delivery rate of the dosing pump of the dosing furnace. According to the second aspect of the invention, the filling area of ​​the sand casting mold is gassed with protective gas while the melt is being poured into the sand casting mold. Both aspects of the invention allow the casting of components from a magnesium alloy using sand casting molds and a dosing furnace system.

[0009] According to an advantageous development of the second aspect of the invention, the filling area of ​​the sand casting mold, which is flushed with protective gas during the filling of the melt into the sand casting mold, is separated from the ambient atmosphere by a cover. This makes it possible to reduce the amount of protective gas used to flush the filling area to an absolute minimum and prevent the protective gas from escaping into the environment.

[0010] The devices according to the invention for casting components made of a magnesium alloy are defined in claims 9 and 10.

[0011] Preferred developments of the invention will become apparent from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1 a sketch to illustrate the method according to the invention for casting components made of a magnesium alloy; and Fig. 2 a detail of the Fig. 1.

[0012] The present invention relates to a method for producing components from a magnesium alloy by casting.

[0013] In a first step of the method according to the invention, a semi-finished product 10 is provided which is formed from a magnesium alloy.

[0014] In a second step of the method according to the invention, the semi-finished product 10 made of the magnesium alloy is positioned in a dosing furnace 11, namely in a melting chamber 12 of the dosing furnace 11. In the dosing furnace 11, the semi-finished product is melted, whereby a melt 13 is then formed.

[0015] The melting of the semi-finished product 10 in the closed melting chamber 12 of the dosing furnace 11 can take place under protective gas, whereby the protective gas cannot escape from the closed melting chamber 12.

[0016] In a third step of the method according to the invention, the melt 13 is removed from the dosing furnace 11, namely in the direction of at least one sand casting mold 14 to be filled with the melt 13, wherein the removal of the melt 13 from the dosing furnace 11 in the direction of the sand casting molds 14 takes place with the aid of a preferably heated chute 15.

[0017] The melt 13 discharged from the dosing furnace 11 is filled into the respective sand casting mold 14 via the trough 15, namely via an outlet area 18 of the trough 15, which is preferably designed as an outlet bend.

[0018] The transfer of the melt 13 from the melting chamber 12 of the dosing furnace 11 into the trough 15 is carried out by means of a dosing pump 16, which sucks the melt 13 from the melting chamber 12 with the aid of a withdrawal pipe 17 and transfers it into the heated trough 15.

[0019] Subsequently, the melt 13 solidifies into the component in the sand casting mold 14 and the component is removed from the sand casting mold 14. In this process, the respective sand casting mold 14 is lost.

[0020] According to a first aspect of the invention, a filling area 19 of the sand casting mold 14, via which the sand casting mold 14 is filled with the melt 13, is monitored by means of a sensor 20, namely in such a way that a filling level of the melt in the filling area 19 of the sand casting mold 14 is detected.

[0021] Depending on this, the delivery rate of the dosing pump 16 is regulated in order to avoid underfilling or overfilling of the filling area 19 of the sand casting mold 14 and thus to enable an optimal filling process of the sand casting mold 14 with the melt.

[0022] If the sensor-detected filling level of the melt in the filling area 19 of the sand casting mold 14 is greater than a target value, the delivery rate of the metering pump 16 is automatically reduced, whereas if the filling level of the melt in the filling area 19 of the sand casting mold 14 is less than the target value, the delivery rate of the metering pump 16 is automatically increased.

[0023] This ensures that the melt is always at an optimal filling level in the filling area 19 of the sand mold 14 and thus that the sand mold 14 is filled optimally.

[0024] At this point, it should be noted that the sand mold can be filled using either the gravity-feed or low-pressure casting principle. In gravity-feed casting, the melt flows by gravity via the channel 15 and the outlet area 18 of the channel 15 into the filling area 19 of the sand mold 14. In low-pressure casting, the output of the metering pump 16 is increased in order to fill the melt into the respective sand mold 14 at a higher filling pressure than in gravity-feed casting, counter to gravity.

[0025] Fig. Figure 2 shows a sensor 20, which is assigned to the channel 15 in the area of ​​the outlet area 18 and which serves to monitor and detect the fill level of the melt in the filling area 19 of the sand casting mold 14. This sensor 20 can detect the fill level either pneumatically, optically, or in some other way.

[0026] According to a second aspect of the invention, which is preferably used in combination with the first aspect of the invention, the filling area 19 of the sand casting mold 14 is gassed with protective gas during the filling of the melt into the sand casting mold 14, wherein for this purpose the channel 15, namely the outlet area 18 of the channel 15, is assigned a gassing device 21, with the aid of which the filling area 19 of the sand casting mold 14 can be gassed during the filling process of the sand casting mold 14. According to Fig. 2, the sensor 20 and the gassing device 21 form a common assembly which is assigned to the outlet area 18 of the channel 15, whereby the installation space available in the area of ​​the filling area 19 can be optimally utilized.

[0027] The gassing of the filling area 19 of the sand casting mold 14 during the filling of the melt into the sand casting mold 14 is preferably carried out continuously.

[0028] According to Fig.2, a lid 22 is assigned to the filling area 19 of the sand casting mold 14 in order to separate the filling area 19 of the sand casting mold 14 from the ambient atmosphere.

[0029] At least one recess is formed in the cover 22, into which the outlet region 18 of the channel 15 and at least the gassing device 21 extend. The cover 22 traps the protective gas introduced into the filling area 19 of the sand casting mold 14 via the gassing device 21 in the area of ​​the sand casting mold 14, preventing the protective gas from escaping into the environment.

[0030] In particular, when the lid 22 is made of a transparent material, such as glass, the filling area 19 can be easily and effectively monitored with the aid of an optical sensor 20.

[0031] A device according to the invention for casting components from a magnesium alloy using sand casting molds 14 in combination with a dosing furnace system accordingly has at least the sensor 20 and / or the gassing device 21, both of which, in the illustrated embodiment, are assigned to the outlet area 18 of the heated chute 15 and the filling area 19 of the sand casting mold 14, respectively. Preferably, the sensor 20 and the gassing device 21 together form an assembly.

[0032] The invention enables effective casting of components made of a magnesium alloy using sand casting molds.

Claims

[1] Process for casting components from a magnesium alloy, comprising the following steps: Providing a semi-finished product (10) made of a magnesium alloy; Melting the semi-finished product to a melt (13) in a dosing furnace (11); Discharging the melt from the dosing furnace (11) with the aid of a dosing pump (16) via a trough (15) and filling the melt via the trough (15) into a sand casting mold (14), wherein the filling level of the melt in a filling area (19) of the sand casting mold (14) is monitored and the delivery rate of the dosing pump (16) is regulated as a function thereof; Solidification of the melt in the sand casting mold (14) and removal of the component from the sand casting mold. [2] Method according to claim 1, characterized bythat when the filling level of the melt in the filling area (19) of the sand casting mold (14) is greater than a target value, the delivery rate of the metering pump (16) is automatically reduced, and that when the filling level of the melt in the filling area (19) of the sand casting mold is less than the target value, the delivery rate of the metering pump is automatically increased. [3] Method according to claim 1 or 2, characterized by that the fill level is detected pneumatically or tactilely. [4] Method according to claim 1 or 2, characterized by that the fill level is recorded optically. [5] Method according to one of claims 1 to 4, characterized by Features according to one of claims 6 to 8. [6] Process for casting components from a magnesium alloy, comprising the following steps: Providing a semi-finished product (10) made of a magnesium alloy; Melting the semi-finished product to a melt (13) in a dosing furnace (11); Discharging the melt from the dosing furnace (11) with the aid of a dosing pump (16) via a trough (15) and filling the melt via the trough (15) into a sand casting mold (14), wherein a filling area (19) of the sand casting mold (14) is gassed with protective gas during the filling of the melt into the sand casting mold (14); Solidification of the melt in the sand casting mold (14) and removal of the component from the sand casting mold. [7] Method according to claim 6, characterized by that the filling area (19) of the sand casting mould is continuously gassed with protective gas while the melt is being filled into the sand casting mould. [8] Method according to claim 6 or 7, characterized by that the filling area (19) of the sand casting mold is separated from the ambient atmosphere by a cover (22). [9] Device for casting components from a magnesium alloy, with a dosing furnace (11) for melting a semi-finished product from a magnesium alloy, wherein the dosing furnace has a dosing pump (16) and a trough (15), wherein melt can be conveyed from a melting chamber (12) of the dosing furnace into the trough (15) via the dosing pump (16), wherein the melt can be fed to a filling area (19) of a sand casting mold via the trough (15), wherein a sensor (20) is assigned to the trough (15) in order to monitor the fill level of the melt in the filling area (19) of the sand casting mold and to regulate the delivery rate of the dosing pump (16) as a function thereof. [10] Device for casting components from a magnesium alloy, with a dosing furnace (11) for melting a semi-finished product from a magnesium alloy, wherein the dosing furnace (11) has a dosing pump (16) and a trough (15), wherein melt can be conveyed from a melting chamber (12) of the dosing furnace into the trough (15) via the dosing pump (16), wherein the melt can be fed to a filling area (19) of a sand casting mold (14) via the trough (15), wherein a gassing device (21) is assigned to the trough (15) in order to gass the filling area (19) of the sand casting mold (14) with protective gas during the filling of the melt into the sand casting mold (14). [11] Device according to claim 9 and 10, characterized by that the sensor (20) and the gassing device (21) form a common assembly. [12] Device according to claim 10 or 11, characterized bythat the filling area (19) of the sand casting mold (14) is separated from the ambient atmosphere by a cover (22). [13] Device according to claim 12, characterized by that the cover (22) has an opening for an outlet area (18) of the channel (15) and for the sensor (20) and / or the gassing device (21). [14] Device according to one of claims 9 to 13, characterized by that the sensor (20) and / or the gassing device (21) is assigned to an outlet area (18) of the channel (15).

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