Device and method for removing at least one cooling element from an at least partially demoulded cast part, method for introducing at least one cooling element into a mould core of a cast part mould

Abstract

The invention relates to a device for removing at least one cooling element from an at least partially demoulded cast part, in particular from a cast housing for an electric motor formed from a light metal alloy, which has an apparatus for removing the at least one cooling element. Furthermore, the invention relates to a method for removing at least one cooling element from an at least partially demoulded cast part, a method for introducing at least one cooling element into a mould core of a cast part mould, a cooling element, and a cast part.

Claims

1. A cooling element for a cast part mould for manufacturing a cast part formed from a light metal alloy, wherein the cooling element is introduced into a mould core of the cast part mould before filling the cast part mould with a light metal alloy melt, is in contact with the light metal alloy melt during filling, and acts to cool the light metal alloy melt filled within the cast part mould, the cooling element comprising: a body having a first surface and a second surface, the first surface opposite the second surface, the first surface being in contact with the light metal melt when the cast part mould is filled; and a removal protrusion protruding from the second surface and configured to be gripped by a gripping mechanism of a removal apparatus when removing the cooling element from an at least partially demoulded cast part, wherein the removal protrusion has a T-shaped cross-section with a shaft extending radially from the second surface and T-bars attached to and extending perpendicularly from an outermost end of the shaft.

2. The cooling element according to claim 1, wherein the removal protrusion extends longitudinally from a first end to a second end and a thickness of the T-bars in the radial direction increases from the first end to the second end.

3. The cooling element according to claim 1, wherein the removal protrusion is formed in one piece, and is connected in a materially bonded manner to the cooling element or detachably connectable to the cooling element.

4. The cooling element according to claim 1, wherein an outer contour of the first surface is substantially identical to a functional inner contour section of a hollow space of the cast part from which the cooling element is removable.

5. The cooling element of claim 1, wherein the removal element extends in a longitudinal direction of the cooling element.

6. The cooling element of claim 1, wherein the removal element is in the form of a rail.

7. The cooling element according to claim 2, wherein the thickness of the T-bars in the radial direction increases linearly from the first end to the second end.

8. A device for removing at least one cooling element according to claim 1 from an at least partially demoulded cast part, the device comprising a removal apparatus comprising a gripping mechanism that engages a removal protrusion attached to the at least one cooling element.

9. The device according to claim 8, wherein the gripping mechanism comprises at least one pair of rails spaced apart from one another, which are configured to engage behind the removal protrusion.

10. The device according to claim 8, wherein the gripping mechanism has a plurality of rail pairs, which are arranged next to one another in a circumferential direction of a substantially rotationally symmetrical removal head and extend parallel or obliquely to a longitudinal axis thereof.

11. The device according to claim 9, wherein each of the rail pairs is detachably connectable to a substantially rotationally symmetrical removal head of the removal apparatus or to the at least one cooling element.

12. The device according to claim 8, wherein a diameter of a substantially truncated cone-shaped removal head of the removal apparatus increases in a direction in which the removal head is movable into a casting cavity for removing the at least one cooling element.

13. A method for removing at least one cooling element according to claim 1 from an at least partially demoulded cast part, wherein a removal apparatus is introduced into a substantially rotationally symmetrical hollow space of the cast part, and the removal protrusion attached to the at least one cooling element is gripped by a gripping mechanism of the removal apparatus.

14. The method according to claim 13, wherein the at least one cooling element is removed from the hollow space by movement of the removal apparatus.

15. The method according to claim 13, wherein, through a movement of the removal apparatus into the rotationally symmetrical hollow space, a movement of the at least one cooling element is effected in a direction of the hollow space, which has a radial movement component.

16. A method for introducing at least one cooling element according to claim 1 into a mould core of a cast part mould wherein the at least one cooling element is introduced into the mould core in such manner that a plurality of surface sections are formed, which are provided for contact with the melt when filling the cast part mould, and wherein at least one of the surface sections is formed by the first surface of the at least one cooling element.

17. The method according to claim 16, wherein the at least one cooling element is introduced into the mould core prior to introducing forming sand into the mold core and is held stationary in the mould core while the forming sand is introduced.

18. The method according to claim 16, wherein the at least one cooling element is introduced into a mould core with the second surface from which the removal protrusion extends abutting against a wall of the mould core.

19. The method according to claim 16, wherein the cooling element is introduced into a first part of an at least two-part mould core and a second part of the mould core is connected to the first part in such a way that the at least one cooling element is engaged in a pocket in each mould core part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail below on the basis of exemplary embodiments and the enclosed drawings relating to the exemplary embodiments. In the drawings is shown:

(2) FIGS. 1a-e a removal device according to the invention in a plurality of views,

(3) FIGS. 2a-b a cooling element according to the invention in different views,

(4) FIGS. 3a-b a removal device according to the invention when removing cooling elements from a cast part,

(5) FIGS. 4a-c a two-part mould core provided with cooling elements according to the invention,

(6) FIGS. 5a-c a one-part mould core provided with cooling elements according to the invention and an associated mould core manufacturing tool.

DESCRIPTION OF THE INVENTION

(7) An apparatus (1) shown in FIG. 1a in a perspective view for removal of eight identical metallic cooling irons (2) arranged next to one another in a circular manner from a cast part not shown in FIG. 1a comprises a substantially truncated cone-shaped removal head (3) shown in detail in FIG. 1c-e, into which eight longitudinal grooves (4) shown in FIGS. 1a+b are inserted, into which is guided a removal protrusion (5) formed integrally on the cooling iron (2) and in a T-shape in the cross-section, which protrudes from one side (6) of the cooling irons (2) facing the removal apparatus (1).

(8) The removal apparatus (1) comprises rails (8, 9) extending in the longitudinal direction of the removal head (3) and formed from a hardened steel, with constant thickness, which are arranged next to one another in pairs in the circumferential direction and are detachably connected to the removal head (3) by a plurality of screws (10). It is also conceivable that the rails (8, 9) have a varying thickness in their longitudinal direction.

(9) The rails (8, 9) are tapered at both ends and are provided for engaging behind T-bars (7) of the removal protrusions (5) when removing the cooling irons (2) from the cast part, as shown in FIG. 1b in a top view from two opposing sides.

(10) To remove the cooling irons (2), the removal head (3) of the removal apparatus (1) is moved in the direction of an arrow (11) shown in FIG. 1a parallel to its longitudinal axis into the cast part, whereby a movement of the cooling iron (2) takes place in the direction of arrows (12) shown in FIG. 1b by way of example. As a result, the cooling irons (2) are removed from a cast part shown in FIGS. 3a-b, centered and can be removed in the same step.

(11) A removal apparatus (1) is shown in detail in FIG. 1c in a perspective view and in FIG. 1d in an exploded view.

(12) In the case of a substantially truncated cone-shaped removal apparatus (1) shown in FIG. 1e in a side view, a surface line (13) inclined by 4 degrees relative to the cone axis is clearly recognisable. This forms a demoulding incline.

(13) Reference is now made to FIGS. 2a-b where the same or identical parts are designated with the same reference numeral as in FIGS. 1a-e and in each case the letter a is added to the reference numeral in question.

(14) A cooling iron (2a) shown in FIG. 2a in a perspective top view of an outer side has a bent surface (14), whose outer contour is almost identical to a functional inner contour section of a hollow space of a cast part (22) designated in FIGS. 3a-b with (23) from which a cooling element (2a) can be removed. The surface (14) is further provided to come into contact with a metal melt with which a cast part mould is filled. This results in a particularly good cast part quality, in particular high strength and low porosity in a cast part region adjacent to the cooling iron (2a). This can, for example, extend up to 25 mm from the cooling iron (2a) and have a porosity with pores with a Feret diameter of max. 0.8 mm.

(15) A first protrusion (16) is integrally formed on a first end face (15), while two further protrusions (18, 19) are formed on a second end face (17). The protrusions (16, 19) are provided to be engaged behind by a mould core into which the cooling iron (2b) is introduced. This achieves both a fixing in the mould core and a flush ending of a surface of the mould core with the bent surface (14) of the cooling iron (2a).

(16) A cooling iron (2a) shown in FIG. 2b in a perspective view of an inner side has a first surface (14) and a second surface (14a), where the first surface (14) is opposite the second surface, and the first surface (14) is in contact with the light metal melt when the mould is filled. The cooling iron (2a) comprises a removal protrusion (5a), which has a T-shaped cross-section and extends in the longitudinal direction (11) of the cooling iron (2a). The T-shaped removal protrusion (5a) has a shaft extending radially from the second surface and T-bars (7a) attached to and extending perpendicularly from an outermost end of the shaft. A thickness of T-bars (7a) in a radial direction (12) increases linearly from a first end (20) of the removal protrusion (5a) to a second end (21) of the removal protrusion (5a). This creates an oblique plane along which slide rails shown in FIGS. 1a-e and designated with (8, 9) during an insertion movement of a removal apparatus not shown in FIGS. 2a-b in the direction of an arrow (11a). This causes a linear movement of the removal apparatus into a movement of the cooling irons (2a) with a radial direction component away from the cast part in the direction of arrows designated in FIG. 1b with (12).

(17) Reference is now made to FIGS. 3a-b, where the same or identical parts are designated with the same reference numeral as in FIGS. 1a-e and 2a-b and in each case the letter b is added to the reference numeral in question.

(18) A housing (22) for an electric motor shown in FIG. 3a in top view and formed from an aluminium alloy comprises a substantially truncated cone-shaped hollow space (23) with a surface line inclined by 1 degree relative to the cone axis, which is provided to receive a stator or a stator carrier of the electric motor not shown in FIGS. 3a-b.

(19) A removal apparatus (1b) for cooling irons (2b) is introduced into the hollow space (23), whose rails (8b, 9b) engage behind T-shaped removal protrusions (5b) of the cooling irons (2b) and which in FIG. 3a is in an initial position in which no removal forces act on the cooling irons (2b). Each cooling iron (2a) abuts and adheres with a surface designated in FIGS. 2a and b with (14) against an associated cast part wall section (24).

(20) During a linear movement of the removal apparatus (1b) into the hollow space (23), the rails (8b, 9b) slide along a steep plane of the removal protrusions (5d) shown in FIGS. 2a-b, whereby a movement of the cooling irons (2b) away from the cast part wall section (24), against which they abut and adhere, is caused with a movement component in a radial direction of the hollow space (23). The cooling irons (2b) are separated from the cast part (22) in an end position shown in FIG. 3b. A gap (25) is formed between the cooling irons (2b) and the associated cast part wall section (24). In this position, the cooling irons (2b) are held by the removal apparatus (1b) and can also be taken out of the hollow space (23) by way of a movement direction opposed to an insertion direction.

(21) The regular arrangement of the rails (8b, 9b) and the movement of the removal apparatus (1b) into an end position further causes a centring of the cooling irons (2b), whereby an automated insertion is made possible into a cooling iron storage pallet not shown in FIGS. 3a-b.

(22) It is also conceivable that the removal apparatus (1b) is inserted into the hollow space on a first side and exits the hollow space (23) on a side facing away from the first side and also takes the cooling irons (2b) with it. Advantageously, this prevents individual cooling irons (2b) becoming stuck when moving out in a movement direction opposed to the insertion direction and causing a standstill in an automated removal process.

(23) Reference is now made to FIGS. 4a-c, where the same or identical parts are designated with the same reference numeral as in FIGS. 1a-e to 3a-b and in each case the letter c is added to the reference numeral in question.

(24) A two-part truncated cone-shaped sand core (26) shown in FIG. 4a in an exploded view and formed from a forming sand has two sand core parts (27, 28) that are connectable to one another by means of a push-in and adhesive connection, by means of which a ring-like protrusion (29) of a first mould core part (27) is inserted into a groove, which is not shown in FIGS. 4a-c and has an adhesive.

(25) A plurality of material recesses (30) are configured to receive cooling irons (2c) in the sand core (26), with T-bars (7c) of a removal protrusion (5c) being gripped by two sand bars (31). While a protrusion (16c) of the cooling iron (2c) shown in FIG. 4c is provided to be inserted into a pocket (32) in the sand core part (27), a further protrusion (19c) engages into a pocket (33) in the sand core part (28).

(26) A total of eight cooling irons (2c) are introduced into an assembled sand core (26) shown in FIG. 4b in a perspective view. Surfaces of sand bars (34) are flush with cooling iron surfaces (14c) and form a flat overall surface which is provided to be in contact with a metal melt, with which the cast part mould is filled, when filling a cast part mould. A cast part produced with such a core is manufactured close to the end contour.

(27) In the case of an assembled two-part sand core (26) shown in the longitudinal section in FIG. 4c, sand bars (31) of a sand core part (27) engage behind T-bars (7c) of retaining protrusions (5c).

(28) Reference is now made to FIGS. 5a-c where the same or identical parts are designated with the same reference numeral as in FIGS. 1a-e to 4a-c and in each case the letter d is added to the reference numeral in question.

(29) A sand core (35) shown in FIG. 5a in a perspective view and in FIG. 5b in a partially sectioned side view is formed integrally. Cooling irons (2d) are introduced, for the manufacture thereof, into a mould core manufacturing tool (36) shown in FIG. 5c in a sectioned side view and fired during a core manufacture, i.e. flowed around with curable forming sand until the mould filling is complete.

(30) The mould core manufacturing tool (36) comprises an upper part (37) and a lower part (38) which enclose a space into which forming sand and cooling irons (2d) can be introduced for the core manufacture and which can be moved relative to one another in order to be able to remove a manufactured mould core.

(31) An upper side (14d) of the cooling irons (2d) abuts against a mould wall surface (39).

(32) Furthermore, retaining recesses (40) are provided in which the retaining protrusions (5d) of the cooling irons (2d) engage, whereby a stationary arrangement is ensured in the mould core manufacturing tool (36).

(33) Although in the exemplary embodiments, a removal apparatus (1; 1b) with a movable removal head (3; 3b) was shown for removal of cooling elements (2-2d) from a cast part (22), which is arranged so as to be stationary, it is conceivable that the removal head (3; 3b) is arranged so as to be stationary and the cast part (22) is movable for removal of the cooling elements.