Method for producing a molded part and feeder insert for use in such a method

Abstract

The invention relates to a method for producing a mold part (26, 26′) with a feeder insert arranged in it, with a sprue for liquid metal, for a divisible casting mold for metal casting, with the following steps: producing or providing a mold part (26, 26′) equipped with a closed feeder insert (2, 2′) from a compacted molding material (28), the closed feeder insert (2, 2′) being arranged fixed in place in the compacted molding material (28) of the mold part (26, 26′) and having a feeder opening (10, 10′) connected to regions of the mold cavity (30, 30′) that is to be formed, and opening the closed feeder insert (2, 2′), so that a sprue (32, 32′) for liquid metal is formed.

Claims

1. A method for producing a mold part (26, 26′, 26″) with a feeder insert arranged in it, with a sprue for liquid metal, for a divisible casting mold for metal casting, with the following steps: producing or providing a mold part (26, 26′, 26″) equipped with a closed feeder insert (2, 2′, 2″) from a compacted molding material (28), the closed feeder insert (2, 2′, 2″) being arranged fixed in place in the compacted molding material (28) of the mold part (26, 26′, 26″) and having a feeder opening (10, 10′) connected to regions of a mold cavity (30, 30′, 30″) that is to be formed or has partially formed, wherein the feeder insert (2″) is a multi-part feeder insert having a feeder element (18″) and a cover (20″), wherein the feeder element (18″) and the cover (20″) are telescopically displaced in relation to one another, wherein the feeder insert is directly in contact with a mold plate or with a mold pattern or is positioned at a small distance from the mold plate and/or the mold pattern and the feeder insert (2″) comprises a filter element held in position at the feeder element (18″) by a securing element (44) during production of the mold part (26″) and opening the closed feeder insert (2, 2′, 2″), so that a sprue (32, 32′, 32″) for liquid metal is formed.

2. The method as claimed in claim 1, the production of the mold part (26, 26′, 26″) equipped with the closed feeder insert (2, 2′, 2″) comprising the following steps: arranging the closed feeder insert (2, 2′, 2″) in a molding chamber or a molding box; filling molding material (28) into the molding chamber or the molding box, the closed feeder insert (2, 2′, 2″) being surrounded at least in certain regions by the molding material (28), and compacting the filled-in molding material (28), so that the mold part (26, 26′, 26″) is produced and the closed feeder insert (2, 2′, 2″) is received fixed in place in the compacted molding material (28).

3. The method as claimed in claim 1, the production of the mold part (26, 26′, 26″) equipped with the closed feeder insert (2, 2′, 2″) comprising the following step: compacting the molding material (28) in contact with the closed feeder insert (2, 2′, 2″), so that the closed feeder insert (2, 2′, 2″) is embedded in an interlocking manner in the mold part (26, 26′, 26″) produced.

4. The method as claimed in claim 1, the production of the mold part equipped with the closed feeder insert (2, 2′, 2″) comprising the following steps: positioning the closed feeder insert (2, 2′, 2″) on a mold plate and/or a mold pattern or at a distance from a mold plate and/or a mold pattern, the closed feeder insert (2, 2′, 2″) being positioned by means of a positioning device, and forming a molding chamber or a molding box for the molding material (28) to be compacted at least in certain regions, from the mold plate and/or the mold pattern (22) and at least one pressing plate that is movable in relation to the mold plate and/or the mold pattern (22).

5. The method as claimed in claim 1, the production of the mold part (26, 26′, 26′) equipped with the closed feeder insert (2, 2′, 2″) also comprising the following steps: providing a closed feeder insert (2′, 2″) that is compressible substantially along its longitudinal axis (38′, 38″); compressing the closed feeder insert (2′, 2″) in the direction of its longitudinal axis (38′, 38″) when compacting the molding material (28).

6. The method as claimed in claim 1, the opening of the closed feeder insert (2, 2′, 2″) comprising one, more than one, or all of the following steps: changing the position of the mold part (26, 26′, 26″) produced together with the closed feeder insert (2, 2′, 2″) arranged fixed in place before the opening of the feeder insert, so that the part of the feeder insert (2, 2′, 2′) later having the sprue (32, 32′, 32″) is arranged with respect to a horizontal plane underneath the feeder opening (10, 10′) connected to regions of the mold cavity (30, 30′, 30″) to be formed; opening the feeder insert (2, 2′, 2″) at a position at a distance from the feeder opening (10, 10′), and working the closed feeder insert (2, 2′, 2″) or working the closed feeder insert (2, 2′, 2″) and regions of the compacted molding material (28) surrounding the feeder insert for opening the feeder insert (2, 2′, 2″) in a or the changed position of the mold part (26, 26′, 26″) produced, together with the feeder insert (2, 2′, 2″) received fixed in place.

7. The method of claim 6, wherein the step of changing the position of the mold part (26, 26′, 26″) comprises turning the mold part (26, 26′, 26″) so that the part of the feeder insert (2, 2′, 2′) later having the sprue (32, 32′, 32″) is arranged with respect to a horizontal plane underneath the feeder opening (10, 10′) connected to regions of the mold cavity (30, 30′, 30″) to be formed.

8. The method of claim 6, wherein the step of opening the feeder insert (2, 2′, 2″) at a position at a distance from the feeder opening (10, 10′) comprises opening the feeder insert (2, 2′, 2″) at an end portion of the feeder opposite from the feeder opening (10, 10′).

9. The method as claimed in claim 1, with the following step: opening the closed feeder insert (2, 2′, 2″) and forming the sprue (32, 32′, 32″) on the feeder insert (2, 2′, 2″) or on the feeder insert (2, 2′, 2″) and the produced mold part (26, 26′, 26″) by machining, leaving after the formation of the sprue (32, 32′, 32″) regions of the mold part (26, 26′, 26″) which reach over wall regions of the feeder insert (2, 2′, 2″) with respect to the pouring-in direction for the liquid metal, so that an undercut enclosing the feeder insert (2, 2′, 2″) is formed and/or removal of the feeder insert (2, 2′, 2″) from the mold part (26, 26′, 26″) produced is prevented.

10. A method for producing a mold part (26, 26′, 26″) with a feeder insert arranged in it, with a sprue for liquid metal, for a divisible casting mold for metal casting, with the following steps: producing or providing a mold part (26, 26′, 26″) equipped with a closed feeder insert (2, 2′, 2″) from a compacted molding material (28), the closed feeder insert (2, 2′, 2″) being arranged fixed in place in the compacted molding material (28) of the mold part (26, 26′, 26″) and having a feeder opening (10, 10′) connected to regions of a mold cavity (30, 30′, 30″) that is to be formed or has partially formed, wherein the feeder insert (2″) is a multi-part feeder insert having a feeder element (18″) and a cover (20″), wherein the feeder element (18″) and the cover (20″) are telescopically displaced in relation to one another, wherein the feeder is directly in contact with a mold plate or with a mold pattern or is positioned at a small distance from the mold plate and/or the mold pattern and the feeder insert (2″) comprises a filter element having an outer diameter held in position at the feeder element (18″) by a securing element (44) during production of the mold part (26″) and opening the closed feeder insert (2, 2′, 2″), so that a sprue (32, 32′, 32″) for liquid metal is formed, wherein the step of opening the closed feeder insert comprises generating an opening in the cover of the feeder insert wherein the opening in the cover has dimensions that are larger than the outer diameter of the filter element to permit the filter element to float on liquid metal during metal casting to increase feeding volume of the feeder element.

11. The method of claim 10, wherein the cover (20″), following the opening step, comprises an abutment to stop the filter element that is floating on liquid metal during metal casting from floating into the sprue.

Description

(1) The invention is described in more detail below on the basis of a preferred exemplary embodiment with reference to the accompanying figures, in which:

(2) FIG. 1: shows a view of a first exemplary embodiment of a closed, one-part feeder insert according to the invention in section;

(3) FIG. 2: shows a view of a feeder insert according to the invention as shown in FIG. 1 positioned on a mold plate or a mold pattern;

(4) FIG. 3: shows a partial view of a mold part made from compacted molding material and the closed feeder insert according to the invention arranged in it, after removal of the mold pattern;

(5) FIG. 4: shows a partial view of the turned mold part that illustrates how the feeder insert according to the invention received in it is opened and a sprue is formed;

(6) FIG. 5: shows a view that shows the pouring of liquid metal into the mold cavity of the created casting mold by way of the sprue formed on the sprue insert according to the invention;

(7) FIG. 6: shows a view of a second embodiment of a closed, compressible multi-part feeder insert according to the invention in section;

(8) FIG. 7: shows a view of a feeder insert according to the invention as shown in FIG. 6 positioned on a mold plate or a mold pattern;

(9) FIG. 8: shows a partial view of a mold part made from compacted molding material and the closed, compressed feeder insert according to the invention arranged in it, after removal of the mold pattern;

(10) FIG. 9: shows a partial view of the turned mold part that illustrates how the feeder insert according to the invention received on it is opened and a sprue is formed;

(11) FIG. 10: shows a view that shows the pouring of liquid metal into the mold cavity of the created casting mold by way of the sprue formed on the feeder insert according to the invention according to the second embodiment;

(12) FIG. 11: shows a view of a further embodiment of a closed, compressible multi-part feeder insert according to the invention in section;

(13) FIG. 12: shows a partial view of a mold part made from compacted molding material and the closed, compressed feeder insert according to the invention arranged in it, after removal of the mold pattern, and

(14) FIG. 13: shows a view that shows the pouring of liquid metal into the mold cavity of the created casting mold by way of the sprue formed on the feeder insert according to the invention according to the third embodiment.

(15) In FIG. 1, a feeder insert 2 according to the invention according to a first embodiment is shown in section. The feeder insert 2 has a feeder body 4, which comprises a feeder cavity 6 for receiving liquid metal. The feeder insert 2 has at a first end 8 on the feeder body 4 a feeder opening 10, by means of which a connection to a mold cavity 30 in a mold part 26 (FIG. 3) can be established. The feeder body 4 is formed as closed at the opposite second end 12 and has side walls 14 extending between the first end 8 and the second end 12. Arranged in the feeder cavity 6 is a filter element 16, with which material flowing through the feeder insert 2 is cleaned. In the present embodiment, the feeder body 4 is of a one-part form, even if the feeder body consists of multiple individual parts, such as a feeder element 18 and a cover 20. One-part should be understood in the present case as meaning that individual parts of the feeder body, such as for example the cover 20, are not intended to be separated from the feeder body 4. Rather, “one-part” should be understood as meaning that, although the feeder body is made up of multiple individual parts, the individual parts are intended to act permanently together with one another. A one-part feeder body preferably cannot be reversibly dismantled into its individual parts, i.e. after dismantling cannot be readily put together again.

(16) FIG. 2 shows the feeder insert 2 according to the invention in an initial arrangement, serving for producing a mold part according to the invention, on a portion of a mold pattern 22. The feeder insert 2 has been placed with its feeder element 18 at the first end 8 on the mold pattern 22, or positioned on it. The positioning of the feeder insert 2 takes place by means of a centering pin 24, over which the feeder element 18 is pushed with the feeder opening 10.

(17) After that, the mold pattern 22 and the feeder insert 2 arranged on it is surrounded by a molding material, which takes place in particular after arranging the feeder insert 2 in a molding chamber or a molding box, which is not shown in any more detail. After that, the molding material is compacted, so that a mold part 26 shown in FIG. 3 of compacted molding material 28 is formed or produced. After producing the mold part 26, the mold pattern 22 is removed, so that a mold cavity 30 is formed adjacent to the feeder element 20. The mold cavity 30 shown in FIG. 3 in this case defines at least regions of the cast part to be produced.

(18) As FIG. 4 illustrates, in a subsequent method step, the mold part 26 produced is changed in its position, that is to say is turned. For this purpose, the mold part 26 is moved into a position in which the feeder insert 2 is “inverted”, the feeder opening 10 being arranged above the second end 12, in which the sprue is to be created. Subsequently, opening of the closed feeder insert 2 takes place at the second end 12 of the feeder body 4, whereby a sprue 32 with at least one pouring opening 34 for the liquid metal is formed. The opening of the feeder insert 2 at the end 20 of the feeder body 4 opposite from the feeder opening 10 takes place by means of working by using a corresponding tool 33. The opening of the feeder insert 2, with the pouring opening 34 being made in the cover 20 of the feeder body 4, involves the associated creation also of a runner 35 and a pouring cup 36 in the compacted molding material 28 of the mold part 26. During the opening of the feeder insert 2 and the forming of the pouring opening 32, the runner 34 and the pouring cup 36, which in the present case define the sprue 32, the mold part is arranged such that, when forming the sprue 32, no molding material gets into the feeder cavity 6 and comes into contact with the filter element 16 arranged in it.

(19) After creating the sprue 32, the mold part 26 is transferred into an alignment usual for use, in which the feeder opening 10 is arranged underneath the pouring opening 34, the longitudinal axis 38 of the feeder insert 2 being vertically aligned in the embodiment shown. The originally closed feeder insert 2 is then formed as a sprue-feeder insert, so that, as FIG. 5 illustrates, a liquid material 40, such as for example metal, is filled in by way of the sprue 32, passes through the feeder insert in the longitudinal direction of the feeder insert 2 and flows into the mold cavity 30. When flowing through the feeder insert 2, the liquid material 40 is cleaned by means of the filter element 16 and the flow of molten material is killed. After solidifying of the liquid material in the mold cavity, the cast part has been created.

(20) FIG. 6 shows a compressible feeder insert 2′, which has a feeder body 4′, which has a feeder element 18′, a feeder part 42′ and a cover 20′. In the embodiment shown, the cover 20′ is fixedly connected to the feeder part 42′ instead of to the feeder element 18′. The cover 20′ is a component belonging to the feeder part 42′, and consequently is preferably an integral part of the feeder part 42′. The feeder part 42′ is a one-part component together with the cover 20′. The feeder insert 2′ is a multi-part feeder insert, the feeder insert 2′ being a closed feeder insert that is compressible along its longitudinal axis. In the embodiment shown, the feeder element 18′ and the further feeder part 42′ along with the cover 20′ are telescopically displaceable in relation to one another. The feeder element 18′ likewise has a feeder opening 10′ arranged at the first end 8 of the feeder insert 2′. The feeder insert 2′ is likewise formed as closed at its second end 12, in particular is closed by way of the cover 20′. Formed in the feeder body 4′ is a feeder cavity 6′, within which a filter element 16′ is arranged or received. In the present embodiment, the side walls 14′ of the feeder insert are formed substantially by the feeder part 42′.

(21) In FIG. 7, the feeder insert 2′ according to the invention has been placed on a mold pattern 22. The positioning of the feeder insert 2′ on the mold pattern 22 takes place by means of a centering pin 24′. Regions or portions of the feeder element 18′ and of the feeder part 42′ have been pushed over the centering pin 24′ and are directly in contact with it. By means of the centering pin 24′, a locational alignment of the feeder insert 2′ in relation to the mold pattern 22 and also an angular alignment of the feeder insert 2′ in relation to the mold pattern 22 takes place, the feeder insert 2′ being aligned with its longitudinal axis 38′ in particular perpendicularly to the surface of the mold pattern 22. As also described in relation to the embodiment shown in FIGS. 1 to 5, the mold pattern 22 and the feeder insert 2′ arranged on it is arranged for example in a molding chamber or a molding box not shown in any more detail, which delimit at least regions of the mold part to be produced. For producing the mold part, the mold pattern 22 and the feeder insert 2′ arranged on it in the molding chamber or the molding box is surrounded at least in certain regions by molding material, which is used for forming a mold part. For this purpose, the molding material used for forming the mold part is filled into the molding chamber or the molding box and then surrounds the mold pattern 22 and the feeder insert 2′.

(22) After that, the molding material 28, which is still in a loose form, is compacted. With the compacting of the molding material 28, indicated in FIG. 8, a solid mold part 26′ is created. On account of the telescopic configuration of the feeder insert 2′, when compacting the molding material a relative movement of the feeder element 18′ and the feeder part 42′ (including the cover 20′) in relation to one another takes place. In particular, the feeder part 42′ is pushed, at least with a portion thereof, over the feeder element 18′. The closed feeder insert 2′ according to the invention is consequently compressible along its longitudinal axis 38′. In an embodiment of the invention that is not shown, instead of the telescopic configuration of the feeder insert 2′, a feeder insert that is compressible, in particular is non-reversibly compressible, is provided.

(23) After the compacting and the associated production of the mold part 26′, the mold part 26′ is changed in its position, that is to say is rotated or turned. The closed feeder insert 2′ is consequently inverted, so that the feeder opening 10 at the first end 8 is arranged above the closed second end 12. After changing the position or aligning the created mold part 26′, it is worked in the region of the feeder insert 2′ and by means of the tool 33 the runner 35′ and the pouring cup 36′ for a sprue 32′ are created in the compacted molding material. In addition to the removal of the molding material, the feeder insert 2 is opened at the closed end 12, i.e. in the region of the cover 20′, and a pouring opening 34′ for the sprue 32′ is formed. By working the molding material 28 from the underside of the mold part 26′, the detached molding material does not get into the interior of the feeder insert, and consequently does not get into the feeder cavity 6′. Consequently, the detached material falls downward because of gravitational force, so that the filter element 16′ does not become clogged. After the opening of the multi-part feeder insert 2′, it is turned back by about 180°. The feeder insert 2′ then has its usual alignment, so that the sprue 32′ is arranged above the feeder opening 10′. The longitudinal axis 38′ of the feeder insert 2 has in the embodiment shown a vertical alignment. In the alignment advantageous for use, shown in FIG. 10, liquid metal 40 is then introduced into the previously closed feeder insert 2′, which is then formed as a sprue-feeder insert, and flows by way of the sprue 32′ through the feeder cavity 6′, the filter element 16′ and the feeder opening 10′ into the mold cavity 30′ in the mold part 36′

(24) In FIG. 11, a further, third embodiment of a feeder insert 2″ according to the invention is shown in section. The feeder insert 2″ has a feeder body 4″, which has a feeder cavity 6″ for receiving liquid metal. The feeder insert 2″ has at the first end 8 of the feeder body 4″ a feeder opening 10. By means of the feeder opening 10, a connection to the mold cavity 30″ of a mold part 26″ is created (FIG. 13). The feeder body 4″ is formed as closed at the opposite, second end 12. In the embodiment shown, the feeder body 4 is closed by a cover 20″, which is coupled to a feeder element 18″. From the first end 8 to the second end 12 of the feeder body 4″, side walls 14″ extend. Arranged within the feeder cavity 6″ is a filter element 16″, which is designed to clean liquid metal filled into the mold cavity 30″ of the mold part 26″ by way of the feeder insert 2″. The filter element 16″ has smaller outer dimensions in comparison with the receiving region on the feeder element 18′″ for the filter element. The filter element 16″ is movable within the feeder insert 2″.

(25) The feeder body 4″, which is made up only of a feeder element 18″ and the cover 20″, is of a two-part form in the embodiment shown. In the present case, the feeder element 18″ and the cover 20″ are telescopically displaceable in relation to one another. The feeder insert 2″ is consequently formed as compressible in the direction of its longitudinal axis 38″. The filter element 16″ is held in position in the interior of the feeder body 4″ by means of a securing element 44. In the present embodiment, the securing element 44 is a a ring body of a foamed plastic. The material used for forming the securing element 44 is a thermally destructible material. Also provided on the feeder element 18″ of the feeder body 4″ are holding elements 46, with which the cover 20″ is held in an initial position in relation to the feeder element 18″. Unwanted premature displacement or telescoping of the feeder element 18″ and the cover 20″ in relation to one another is avoided. The holding elements 46 are designed to break away from the feeder element 18″ or to be deformed and/or to penetrate into the side wall 14″ of the cover 20″ above a certain minimum compressive force.

(26) As similarly revealed by FIGS. 2 and 7, the feeder insert 2″ is placed onto a mold pattern not shown in any more detail with a centring pin. Subsequently, the feeder insert 2″ together with the mold pattern is surrounded by a molding material 28, which takes place in particular after arranging the feeder insert 2″ in a molding chamber or a molding box, which is likewise not shown in any more detail.

(27) FIG. 12 shows the feeder insert 2″ according to the invention within a mold part 26″ already produced from the compacted molding material 28 and after the removal of the mold pattern defining the mold cavity 30″ within the mold part 26″. With the compacting of the molding material 28, the cover 20″ reaching over the outside of the feeder element 18″ is displaced in the direction of the longitudinal axis 38″ of the feeder insert 2″, and in this way the feeder insert 2″ is compressed. The side walls 14″ of the cover 20″ push over the side walls 14″ on the outside of the feeder element 18″. The cover 20″ has a stop 48, which comes into contact with the second end of the feeder element 18″ when the cover 20″ is displaced. By means of the stop 48, the telescoping capability of the feeder element 18″ and the cover 20″ is limited. Consequently, a cavity remains above the filter element 16″ in the feeder insert 2″ for its freedom of movement.

(28) As shown similarly in FIGS. 4 and 9 in relation to the other embodiments, after the production of the mold part 26″, in inverted alignment on the arrangement consisting of the mold part 26″ and the feeder insert 2″, by means of a tool 33 at least the feeder insert 2″ is opened, in particular the sprue 32″, comprising a pouring opening 34″ on the feeder insert 2″, a runner 35″ and a pouring cup 36″ (FIG. 13) is created.

(29) After the forming of the sprue 32″ and the associated opening of the feeder insert 2″, the mold part 26″ with the feeder insert 2″ is brought into the alignment advantageous for usual use, shown in FIG. 13. After that, liquid material 40, in particular liquid metal, is filled into the sprue 32″. The liquid material 40 flows through the feeder insert 2″ into the mold cavity 30″ of the mold part 26. With the filling in of the liquid material, which is at a temperature of several hundreds of degrees, the securing element 44 holding the filter element 16″ in position is destroyed, so that, as FIG. 13 illustrates, the filter element 16″ in the feeder cavity 6″ of the feeder insert 2″ is released. When the liquid metal rises up in the feeder cavity 6″ of the feeder insert 2″, the filter element 16″ floats on the molten material.

(30) It goes without saying that, for simplified representation of the invention, the figures reproducing the casting operation, FIGS. 5, 10 and 13, only show regions of the mold part 26, 26′, 26″ and only segments of a casting mold required for producing a cast part. To form a complete casting mold, at least one further mold part is required, delimiting the lower part of the cast part to be produced that is not represented.

LIST OF DESIGNATIONS

(31) 2, 2′, 2″ Feeder insert

(32) 4, 4′, 4″ Feeder body

(33) 6, 6′, 6″ Feeder cavity

(34) 8 First end

(35) 10, 10′ Feeder opening

(36) 12 Second end

(37) 14, 14′, 14″ Side wall

(38) 16, 16′, 16″ Filter element

(39) 18, 18′, 18″ Feeder element

(40) 20, 20′, 20″ Cover

(41) 22 Mold pattern

(42) 24, 24′ Centering pin

(43) 26, 26′, 26″ Mold part

(44) 28 Molding material

(45) 30, 30′, 30″ Mold cavity

(46) 32, 32′, 32″ Sprue

(47) 33 Tool

(48) 34, 34′, 34″ Pouring opening

(49) 35, 35′, 35″ Runner

(50) 36, 36′, 36″ Pouring cup

(51) 38, 38′, 38″ Longitudinal axis

(52) 40 Material

(53) 42′ Feeder part

(54) 44 Securing element

(55) 46 Holding element

(56) 48 Stop