One-piece feeder body for use while casting metals

Abstract

The invention relates to a single-part feeder body for use as a feeder insert or component of a two-part or multi-part feeder insert in metal casting, having a feeder wall which at least partially delimits a feeder cavity for receiving liquid metal, wherein the feeder wall has an inner surface facing toward the feeder cavity, an outer surface for bearing against a mold material that surrounds the feeder body in certain regions, and a passage opening for the liquid metal into the feeder cavity, wherein the feeder wall has, on the inside, one, two or more material recesses for forming one or more outwardly protruding projections on the metal solidifying within the feeder cavity.

Claims

1. A single-part feeder body (1) for use as a feeder insert or component of a two-part or multi-part feeder insert (30) in metal casting, having a feeder wall (2) which at least partially delimits a feeder cavity (10) for receiving liquid metal, wherein the feeder wall (2) has an inner surface (3) facing toward the feeder cavity (10), an outer surface (4) for bearing against a mold material that surrounds the feeder body (1) in certain regions, and a passage opening (8) for the liquid metal into the feeder cavity (10), wherein the feeder wall (2) has, on the inside, at least one material recess (12) for forming at least one outwardly protruding projection, respectively, on the metal solidifying within the feeder cavity (10), wherein the material recess (12) is designed such that metal solidifying in the feeder cavity (10) forms an undercut.

2. The feeder body (1) as claimed in claim 1, wherein the at least one material recess (12) defines an inner surface section (14), facing toward the passage opening (8), of the feeder wall, which inner surface section is at an angle α in the range of 70° to 110 with respect to a central axis (18) of the passage opening (8), and/or has one or more planar surface regions (16, 16′) which protrude outward in the feeder wall (2).

3. The feeder body (1) as claimed in claim 1, wherein multiple material recesses (12) are arranged at angular intervals around a central axis (18) of the passage opening (8).

4. The feeder body as claimed in claim 3, wherein three material recesses (12) are arranged with an offset of approximately 120 angular degrees with respect to one another on the inner surface (3).

5. The feeder body (1) as claimed in claim 1, wherein the feeder cavity (10) narrows from the at least one material recess (12) in the direction of the passage opening (8) and/or a constriction (28) with a minimal passage cross section is integrated into the feeder body (1) in the region of the passage opening (8).

6. The feeder body (1) as claimed in claim 1, wherein the feeder body (1) has a first end (22), which defines the passage opening (8), and a second end (24), which is situated opposite the passage opening (8) and which is open.

7. The feeder body (1) as claimed in claim 6, wherein the at least one material recess (12) extends as far as the open second end (24).

8. The feeder body (1) as claimed in claim 1, wherein the at least one material recess (12) on the inside has a height parallel to a central axis (18) of the passage opening (8), which height is in the range of 0.25 to 0.5 in relation to the total height of the feeder body (1).

9. The feeder body (1) as claimed in claim 1, wherein the at least one material recess (12) has a height parallel to a central axis (18) of the passage opening (8) of at least 10 mm and/or a thickness, measured perpendicular to the central axis (18) of the passage opening (8), of at least 3 mm and/or a minimum spacing to the passage opening (8) of approximately 10 mm.

10. The feeder body (1) as claimed in claim 1, wherein the feeder body (1) (i) is formed from exothermic feeder material or comprises exothermic feeder material in certain sections, and/or (ii) is formed from insulating feeder material or comprises insulating feeder material in certain sections.

11. The feeder body (1) as claimed in claim 1, wherein the feeder cavity (10) is designed to be rotationally symmetrical about a central axis (18) of the passage opening (8) and/or the outer surface of the feeder body (1) is designed to be symmetrical in a plane running through the central axis (18) of the passage opening (8), and/or the feeder body (1) has a mounting region (6) which narrows in the direction of the passage opening (8) and which serves for mounting on a mold model or on a mold plate (20).

12. A two-part or multi-part feeder insert (30) for use in metal casting in casting molds, comprising a feeder body (1) as claimed in claim 1, and one or more further feeder elements (32), wherein the feeder body (1) is connected to the one or more further feeder elements (32) to form the feeder insert (30) and wherein the feeder body (1) together with the one or more further feeder elements (32) defines the feeder cavity (10).

13. The feeder insert (30) as claimed in claim 12, wherein the feeder body (1) and the one or more further feeder elements (32) are designed to be telescopic relative to one another.

14. The feeder insert (30) as claimed in claim 12, wherein the feeder body (1) has a narrowing mounting region (6) on its outer surface, and/or wherein the feeder body (1), as a lower part of a feeder insert (30), is of rotationally symmetrical form.

15. A kit for producing feeder inserts (30), comprising one or more feeder bodies (1) as claimed in claim 1, and at least two further feeder elements (32) which correspond with the one or more feeder bodies (1) such that two or more different feeder inserts (30) can be generated, wherein each feeder cavity has a different volume.

16. The kit as claimed in claim 15, comprising a centering mandrel which corresponds with a passage opening (8) in the one or more feeder bodies (1).

17. A device for producing a feeder body (1) as claimed in claim 1, comprising: a molding box, having at least two mold parts which are movable relative to one another, wherein a first mold part is configured to at least regionally form the outer surface of the feeder body (1), and wherein a second mold part is configured to at least regionally form the inner surface (3), which delimits the feeder cavity (10), of the feeder body (1), wherein the second mold part, on its surface that at least regionally forms the inner surface (3) of the feeder body (1), has one or more outwardly protruding mold part projections which are configured to form the at least one material recess (12).

18. A method for producing a casting with a residual feeder arranged thereon, wherein the residual feeder has at least one outwardly protruding metallic projection as a counterbearing for a separating wedge that can be brought into contact with the at least one metallic projection, comprising the steps: providing or producing a casting mold which is equipped with at least one feeder body (1) as claimed in claim 1 and which has a mold cavity; casting liquid metal into the mold cavity of the casting mold through a sprue formed on the casting mold, such that liquid metal enters the feeder cavity, allowing the metal to solidify in the mold cavity and in the feeder cavity (10), such that the residual feeder is formed as a result.

19. The method as claimed in claim 18, comprising the steps: providing or producing a first mold part which is equipped with at least one feeder body (1) as claimed in claim 1 and which has a first parting surface for partially defining the mold cavity of the casting mold; providing or producing a second mold part which serves for partially defining the mold cavity of the casting mold and which has a second parting surface of complementary form with respect to the first parting surface, joining the first parting surface of the first mold part to the second parting surface of the second mold part, such that the casting mold which is equipped with the at least one feeder body (1) and which has the mold cavity is formed as a result.

20. A method for producing a casting, having the following steps: producing a casting with a residual feeder arranged thereon as claimed in claim 18, and processing the casting, wherein the residual feeder arranged on the casting is separated off by means of a separating wedge which engages on the at least one outwardly protruding metallic projection of said residual feeder.

Description

(1) The invention will be described in more detail below, with reference to the appended figures, on the basis of a preferred exemplary embodiment of a feeder body according to the invention and of a feeder insert according to the invention, from which further features which are preferred for the present invention are apparent. In the figures:

(2) FIG. 1: shows a perspective illustration of a feeder body according to the invention for use in metal casting;

(3) FIG. 2: shows a plan view of the feeder body according to the invention as per FIG. 1;

(4) FIG. 3: shows a side view of the feeder body according to the invention;

(5) FIG. 4: shows a sectional illustration of the feeder body according to the invention as per FIG. 1; and

(6) FIG. 5: shows a sectional illustration of a feeder insert according to the invention, assembled from a feeder body according to the invention and a feeder element, for use in metal casting in casting molds.

(7) FIG. 1 shows a single-part feeder body 1 according to the invention which is used in metal casting in a casting mold (not shown in any more detail). The feeder body 1 has a feeder wall 2 with an inner surface 3 which is configured to at least partially delimit a feeder cavity 10 (FIG. 4) for receiving liquid metal. The feeder wall 2 of the feeder body 1 furthermore comprises an outer surface 4 which is configured as a bearing surface for a mold material which regionally surrounds the feeder body and by means of which the casting mold is formed. A mounting region 6 of the feeder body is provided on the outer surface 4, by means of which mounting region the feeder body 1 is mounted on a mold model and/or a mold plate 20 (FIG. 5). In an alternative embodiment which is not illustrated, the outer surface has, instead of the mounting region 6, a wall region by means of which a wall section of a mold cavity of the casting mold can be formed.

(8) A passage opening 8 (FIG. 2; FIG. 4) for the liquid metal into the feeder cavity is arranged at the mounting region 6 of the feeder body 1 shown in FIG. 1. According to the invention, the feeder body 1 has three material recesses 12 on its inner surface 3 in the present embodiment, which material recesses are configured such that a corresponding number of outwardly protruding projections are formed on the metal solidifying within the feeder cavity. The material recesses 12 have one or more planar inner surface sections 14 and/or surface regions 16, 16′ (FIG. 2) running at an angle α (FIG. 4) with respect to the inner surface 3. In particular, an undercut that acts in the direction of the passage opening 8 is formed by means of the inner surface section 14 of the material recesses 12.

(9) As can be seen from FIG. 2, the multiple material recesses 12 are arranged on the inner surface 3 of the feeder wall 2 at uniform angular intervals around a central axis 18 of the passage opening 8. Adjacent material recesses 12 preferably have an offset of approximately 120 angular degrees with respect to one another on the inner surface 3. The feeder body 1 has a first end 22 defined by the mounting region 6. A second, upper end 24 of the feeder body 1 is formed opposite the first end 22. The second end 24 is designed to be open in the embodiment shown. As can be seen from FIGS. 1 and 4, the material recesses 12 on the inner surface 3 of the feeder wall 2 extend as far as the second end 24 of the feeder body 1. In particular, in the region of the material recesses 12, the wall thickness of the feeder wall 2 in the direction of the outer surface 4 is reduced in relation to the wall thickness from the inner surface 3 to the outer surface 4. In an embodiment that is not shown in any more detail, the material recesses end, spaced apart from the second end, on the feeder body 1 without a step, such that the feeder body, at its upper end, is defined with regard to its cross section solely by the uniform encircling inner surface 3.

(10) FIG. 3 shows a side view of the feeder body 1 according to the invention, which shows that the feeder body 1 has a sleeve section 26 with an outer cross section which increases slightly from the second end in the direction of the first end. A narrowing outer contour, similar to a cone, adjoins the sleeve section 26. In particular, the feeder body 1 has a narrowing mounting region 6. As can also be seen from FIG. 2, the single-part feeder body 1 according to the invention is of substantially rotationally symmetrical form. The single-part feeder body shown in FIG. 3 can, in one embodiment of the invention, be used as a single-part, open or closed feeder insert, not shown in detail, within a casting mold. Such a single-part feeder insert is for example retroactively inserted into a prefabricated casting mold or a prefabricated mold part of a casting mold.

(11) The sectional view of the feeder body 1 according to the invention shown in FIG. 4 illustrates the preferably planar configuration of the inner surface section 14, which protrudes outward from the inner surface 3, for forming the undercut on the inner surface 3. The inner surface section 14 of the material recesses 12 extends to the central axis 18 of the passage opening at an angle α in the range from 70° to 110°. As can also be seen from FIG. 4, the material recess on the inner surface 3 is formed without an undercut in the direction of the second end 24, whereby a feeder body 1 thus designed in accordance with the invention can, after being produced, be removed in a non-destructive manner from a mold part that forms the inner surface 3 of the feeder body 1. This is also achieved in that the inner surface 3 of the feeder wall 2 is designed such that the feeder cavity 10 narrows from the second end 24 of the feeder body 1 in the direction of the passage opening. In particular, the feeder cavity 10 has a cross section that narrows in the direction of the passage opening 8. In the embodiment shown, the inner surface 3 has an approximately conical shape. Furthermore, in the region of the passage opening 8, a constriction 28 with a minimal passage cross section for forming a breaker core is integrated into the feeder body 1.

(12) The material recesses 12 have a height substantially parallel to the central axis of the passage opening 8, which height is in the range of approximately 0.25 to approximately 0.5 in relation to the total height of the feeder body. The material recess has a height dimension of at least 10 mm and a minimum thickness in the region of the greatest offset with respect to the inner surface 3 of at least 3 mm. The absolute dimensions of the material recesses 12 may vary in a manner dependent on the basic dimensions of the single-part feeder body 1 according to the invention.

(13) The feeder body 1 may be formed from an exothermic feeder material or may comprise exothermic feeder material in certain sections. In an alternative embodiment, the feeder body is composed of insulating feeder material or is formed from insulating feeder material at least in certain sections. In a further possible embodiment, the feeder body is formed in certain regions from exothermic and insulating feeder material.

(14) FIG. 5 shows an embodiment of a two-part feeder insert 30 according to the invention, which comprises a feeder body 1 according to the invention which, in the embodiment shown, interacts with a feeder element 32. The feeder cavity 10 is defined by the feeder body 1 and the feeder element 32. The feeder insert 30 is a multi-part, closed feeder with a passage opening 8 at the mounting region 6 of the feeder body 1. Feeder body 1 and feeder element 32 are designed to be telescopic relative to one another, wherein, in the present embodiment, the feeder body 1 usually stands fixedly on a mold plate 20 or on a mold model not illustrated in any more detail. During the compaction of the mold material surrounding the feeder insert 30 to form at least one mold part of a casting mold, the feeder element 32 is moved parallel to the central axis 18 of the feeder body 1 and thus in the longitudinal direction 34 of the feeder insert. In particular, the feeder element 30 is pushed in certain sections over the single-part feeder body 1. As can also be seen from FIG. 5, the feeder element 32 has a receptacle 36 for a centering mandrel which interacts with the feeder insert 30 but which is not shown in any more detail.

LIST OF REFERENCE DESIGNATIONS

(15) 1 Feeder body 2 Feeder wall 3 Inner surface 4 Outer surface 6 Mounting region 8 Passage opening 10 Feeder cavity 12 Material recess 14 Inner surface section 16, 16′ Surface region 18 Central axis 20 Mold plate 22 First end 24 24 Second end 26 Sleeve section 28 Constriction 30 Feeder insert 34 Feeder element 34 Longitudinal direction 36 Receptacle