Foundry core

Abstract

The present invention relates to a foundry core, which has the base form of a hollow body, with the foundry core being formed from a moulding material consisting of a mixture which is formed from a moulding sand and a binder and optionally from additives added to set its properties and a method for its manufacture. The foundry core according to the invention can be easily manufactured. This is achieved as a result of the foundry core being divided into at least two sub-segments and forming elements interacting with one another in a positive-locking manner being provided on the edge sides, with which sub-segments arranged adjacent to one another abut on one another, or in proximity to these edge sides, via which forming elements the sub-segments arranged adjacent to one another are fixed by positive locking immovably against one another at least in one direction.

Claims

1. A foundry core, wherein the foundry core is shaped from a moulding material consisting of a mixture which is formed from a moulding sand and a binder and optionally from additives added to set its properties wherein the foundry core is divided into at least two sub-segments and wherein forming elements interacting with one another in a positive-locking manner are provided on edge sides, with which sub-segments arranged adjacent to one another abut on one another, or in proximity to these edge sides, via the forming elements the sub-segments arranged adjacent to one another are fixed by positive locking immovably against one another at least in one direction, characterised in that the core has a base form of a hollow cylinder extending in a longitudinal direction with two end faces opposed to one another in the longitudinal direction, and in that the core is formed at least over one section as a strip running in a meandering shape around a space delimited by the foundry core.

2. The foundry core according to claim 1, characterised in that the at least two sub-segments are adhered to one another at least in the region of their forming elements fixed against one another in a positive-locking manner.

3. The foundry core according to claim 2, characterised in that separating joint extends between the two sub-segments adjacent to one another from one end face of the foundry core to the other.

4. The foundry core according to claim 1, characterised in that separating joint extends between the two sub-segments adjacent to one another at least in sections in the longitudinal direction of the foundry core.

5. The foundry core according to claim 1, characterised in that separating joint runs between the two sub-segments adjacent to one another in a circumferential direction of the foundry core.

6. The foundry core according to claim 1, characterised in that as the forming elements, via which the two sub-segments adjacent to one another are fixed by positive locking immovably against one another in the at least one direction, on the edge side of a first sub-segment a projection is formed and on the edge side of a second sub-segment a recess is formed, which fills the projection of the first sub-segment.

7. The foundry core according to claim 1, characterised in that the forming elements are formed as projections protruding in a radial direction, via which adjacent sub-segments are fixed by positive locking immovably against one another in the at least one direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail below using a drawing representing an exemplary embodiment. Its figures in each case schematically show in:

(2) FIG. 1 a foundry core in a perspective view from above;

(3) FIG. 2 a section A of the foundry core according to FIG. 1;

(4) FIG. 3 the lower part of a core shooting box in plan view.

DESCRIPTION OF THE INVENTION

(5) The foundry core 1 has the base form of a cylindrical hollow body and accordingly delimits an interior IR, which extends in the longitudinal direction LR from the lower end face SU to the upper end face SO of the foundry core 1.

(6) The foundry core 1 shaped from a moulding material proven for this purpose and mixed from a forming sand and an organic or inorganic binder in a manner known per se serves to represent a cooling water sheath in a housing for an electric motor serving as a vehicle drive, which is cast in a casting mould, not illustrated further here and for example composed as a core packet, made of a light metal melt, such as for example of a conventional aluminium cast material.

(7) The circumferential wall 2 of the foundry core 1 is formed by an annular segment-shaped annular section 3 circulating around the longitudinal axis LX of the foundry core 1 and a meander section 4.

(8) Proceeding from a projection 5 protruding outwards in the radial direction RR and representing an inflow opening in the finished housing, the annular section 3 formed in the manner of a strip with a certain thickness extends over roughly three quarters of the circumference of the foundry core 1.

(9) The start of the meander section 4 is connected to the end of the annular section 3. The windings 6 of the meander section 4 are in each case placed such that their longitudinal sections 7 are axially-parallel to the longitudinal axis LX. In this case, the meander section 4 runs proceeding from the end of the annular section 3 in an opposing direction of the annular section 3 around the interior IR delimited by the foundry core 1 until it arrives, with its end provided at the end of a longitudinal section 7, adjacent to the start of the meander section 4. The projection 8 protruding radially outwardly there forms, in the finished housing, the draining opening of the water sheath to be formed by the foundry core 1.

(10) The foundry core 1 is subdivided into nine sub-segments 9-17. The first sub-segment 9 extends proceeding from the projection 5 over half the length of the annular section 3. The second sub-segment 10 takes in the second half of the annular section 3. The third to ninth sub-segment 11-17 extends in each case over roughly one seventh of the length of the meander section 4, with the ninth sub-segment 17 being longer around the longitudinal section leading to the end of the meander section 4 than the other sub-segments 11-16 of the meander section 4.

(11) The separating joints (of which the separating joints 18-24 are visible in FIG. 1), in which the sub-segments 9, 10; 10, 11; 11, 12; 12, 13; 13; 14; 14; 15; 15, 16; 16; 17 abut against one another, run in each case in a first section 25 in the longitudinal direction LR and in an adjoining section 26 in the circumferential direction UR, and the angle formed between the sections 25 and 26 can be unequal to 90, the alignment of the section 25 thus can have not only one component in the longitudinal direction LR, but also in the circumferential direction UR and the alignment of the section 26 can have not only one component in the circumferential direction UR, but also in the longitudinal direction LR.

(12) In this case, in the region of each separating joint 18-24 adjoining the edge sides of the sub-segments 9-16 meeting one another in the separating joint 18-24, a forming element 27a, 27b, 28a, 28b, 29a, 29b, 30a, 30b is designed in the form of a projection protruding radially outwardly. Of the pairs 27a, 27b; 28a, 28b; 29a, 29b; 30a, 30b of forming elements 27a-30b formed in such a manner at the separating joints 18-24, one forming element 27a, 28a, 29a, 30a has in each case one recess 31 extending over its projection length LV, which is shaped in the manner of a notch shaped in the cross-section corresponding to three-quarters of a circle. The forming elements 27b, 28b, 29b, 30b assigned in each case to the forming elements 27a, 28a, 29a, 30a are accordingly wedge-shaped with a cross-section that is also in a three-quarter circle shape. In this manner, the forming elements 27b, 28b, 29b, 30b in each case fill the recess 31 of the assigned forming elements 27a, 28a, 29a, 30a such that projections protruding radially outwardly formed by forming element pairs 27a, 27b; 28a, 28b; 29a, 29b; 30a, 30b have a cross-section shaped circular as a whole.

(13) Via the forming elements 27a-30b provided in each case on the sub-segments 9-17 and their edge sides abutting on one another in the region of the separating joints 18-24, the sub-segments 9-17 are fixed in a positive-locking manner in the circumferential direction UR and in the longitudinal direction LR such that a relative movement in the circumferential direction UR and in the longitudinal direction LR is prevented on the lower end face SU.

(14) In order to manufacture the annular core 1, a core shooting box is provided of which the lower part 40 is represented in FIG. 3. The core shooting box not shown further here for the sake of clarity is set up such that the sub-segments 9-17 for two identical annular cores 1 can be shot in it. Accordingly, two sets of mould cavities 49-57 spatially separated from one another are formed in a corresponding manner in the lower part 40 of the core shooting box and in the associated upper part of the core shooting box not represented here. After shooting the core box, two sets of sub-segments 9-17 can be hereby shot in a manner known per se. They are then composed to form two annular cores 1. In this case, this composition can take place before the foundry cores 1 are set into the respective casting mould or the sub-segments 9-17 can be composed in the respective casting mould to form the foundry core 1 provided in it.

REFERENCE NUMERALS

(15) 1 foundry core 2 circumferential wall of the foundry core 1 3 annular section of the foundry core 1 4 meander section of the foundry core 1 5 projection 6 windings 7, 7 longitudinal sections 8 projection 9-17 sub-segments 18-24 separating joints 25 section of the separating joints running in the longitudinal direction LR 26 section of the separating joints running in the circumferential direction UR 27a-30b forming elements 31 recess 40 core box lower part 49-57 mould cavities IR interior delimited by foundry core LR longitudinal direction of the foundry core 1 LV projection length UR circumferential direction of the foundry core 1 RR radial direction SU lower end face of the foundry core 1 SO upper end face of the foundry core 1 LX longitudinal axis of the foundry core 1