Casting mold and process for manufacturing a crankcase

Abstract

A casting mold for a crankcase of an internal combustion engine includes a water jacket core which has a frame core and a cooling duct core. A land core is provided which is designed and positioned in such a way as to form a cooling duct in an inter-cylinder land of a crankcase. The land core is retained in the frame core and is, or can be, centered using a top core.

Claims

1. A casting mold for a crankcase of an internal combustion engine, comprising: a water jacket core, wherein the water jacket core has a frame core and a cooling duct core; and a land core, wherein the land core is insertable in the water jacket core to form a cooling duct in an inter-cylinder land of the crankcase; wherein the land core is retained in the frame core and is centerable using a top core; wherein the land core has a cooling duct portion and wherein the land core bears via a plurality of retaining surfaces of the land core against or on the frame core; wherein the plurality of retaining surfaces are oriented perpendicular to a cylinder axis of the crankcase and are offset relative to the cooling duct portion in a longitudinal direction of the water jacket core; wherein the land core has a plurality of arrangement portions which extend away from the cooling duct portion and wherein the plurality of arrangement portions each have a respective retaining surface on an end face thereof; wherein the plurality of arrangement portions are land-shaped and follow a cylindrical contour.

2. The casting mold according to claim 1, wherein the water jacket core is centered before the land core when the casting mold is closed.

3. The casting mold according to claim 1, wherein the land core has a plurality of cooling duct portions arranged on top of one another.

4. The casting mold according to claim 1, wherein the land core has a support element for increasing a stability of the land core.

5. The casting mold according to claim 4, wherein the support element is disposed above the cooling duct portion.

6. The casting mold according to claim 4, wherein the support element is configured as a core bearing and/or a core print.

7. The casting mold according to claim 1, wherein a retaining surface is configured on the cooling duct portion.

8. The casting mold according to claim 7, wherein the retaining surface is configured as a front projection and/or a rear projection.

9. The casting mold according to claim 1, wherein a respective core shooter is provided on the plurality of arrangement portions.

10. A process for manufacturing a crankcase of an internal combustion engine, comprising the acts of: providing a casting mold with a water jacket core, wherein the water jacket core has a frame core and a cooling duct core; inserting a land core in the frame core; and centering the water jacket core and then centering the land core via a top core; wherein the land core has a cooling duct portion and wherein the land core bears via a plurality of retaining surfaces of the land core against or on the frame core; wherein the plurality of retaining surfaces are oriented perpendicular to a cylinder axis of the crankcase and are offset relative to the cooling duct portion in a longitudinal direction of the water jacket core; wherein the land core has a plurality of arrangement portions which extend away from the cooling duct portion and wherein the plurality of arrangement portions each have a respective retaining surface on an end face thereof; wherein the plurality of arrangement portions are land-shaped and follow a cylindrical contour.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective view of an embodiment of a land core.

(2) FIG. 2 shows a perspective view of a water jacket core, in addition to a plurality of land cores.

(3) FIG. 3 shows a sectional view of a water jacket core in which a plurality of land cores are arranged.

(4) FIG. 4 shows a further sectional view of the water jacket core of FIG. 3.

(5) FIG. 5 shows a plan view of a further embodiment of a land core.

(6) FIG. 6 shows a further embodiment of a land core with a three-point bearing.

DETAILED DESCRIPTION OF THE DRAWINGS

(7) FIG. 1 shows in a perspective view a land core 30 which in its central region has two cooling duct portions 32 which are connected together. A total of four arrangement portions 34 extend away therefrom, wherein these arrangement portions have retaining surfaces 36 on the end face which are designed to bear and/or arrange the land core 30 on a frame core, not shown here, of a water jacket core. A support element 38 is provided between the arrangement portions 34 and/or above the cooling duct portions 32, in particular for reinforcing and/or stabilizing the entire land core 30. In addition to the retaining surfaces 36, on the end face the arrangement portions 34 have vertical arrangement surfaces 40 which amongst other things serve for pre-centering the land core in the frame core of the water jacket core. In addition, the arrangement portions 34 are configured on the end face such that a centering of the land core 30 is possible via a further core, not shown here, for example a top core or cover core. In other words, the arrangement portions on the end face form core bearings and/or core prints 39 which are provided for centering in corresponding core prints, for example of a top core. Alternatively and/or additionally, the support element 38 preferably serves as a core bearing and/or core print.

(8) FIG. 2 shows in a perspective view a water jacket core 20 which extends along a longitudinal axis L and which has a frame core 22 and a cooling duct core 24. The cooling duct core 24 is that region and/or portion of the water jacket core 20 which forms the actual “water jacket” in the finished crankcase. The four cylinder openings may be identified clearly, wherein in each case a land core 30 is arranged and/or provided between these cylinder openings, i.e., in the lands of the subsequent cylinder. The reference numeral 32 refers to the cooling duct portions of the land cores 30. Moreover, the embodiment of the land cores 30 shown here corresponds to that disclosed in FIG. 1 so that reference is made thereto. It should also be mentioned that the shape of the land cores 30 permits a simple insertion or positioning in the frame core 22 of the water jacket core 20, in particular by the alignment of the retaining surfaces and/or (vertical) arrangement surfaces, see FIG. 1. The arrangement portions follow the cylindrical contour. Along the longitudinal axis L of the water jacket core 20 the retaining surfaces of the land core 30 are offset relative to the cooling duct portion 32 and/or to the cooling duct portions 32, whereby the cooling duct portions 32 are arranged approximately centrally between the retaining surfaces of the arrangement portions. As a result, an exceptionally stable land core 30 is produced, the land core additionally being able to be positioned exceptionally accurately.

(9) FIG. 3 now shows a sectional view of the water jacket core disclosed in FIG. 2, along the longitudinal axis L. In particular, the frame core 22 and the actual cooling-duct core 24 of the water jacket core may be identified. A total of three land cores 30 may be identified, wherein the respective arrangement portions 34 of the two outer land cores are only partially shown. The arrangement portions 34 in each case have retaining surfaces 36, whereby they are supported and/or bear against the frame core 22 of the water jacket core. In particular, the very thin cooling portions 32 which form the subsequent land cooling ducts may be identified. A support element 38 denoted by the reference numeral 38 is arranged thereabove, the support element significantly increasing the stability of the entire arrangement and advantageously serving as a core bearing and/or core print.

(10) FIG. 4 shows a further sectional view transversely to the longitudinal axis L, wherein once again the cooling portions 32 of the land core 30 and/or the spacing thereof from the cooling-duct core 24 of the water jacket core 20 may be identified. Moreover, in this view the path of the supporting element 38 and/or the arrangement portions 34 with the retaining surfaces 36 thereof configured on the end face may be identified. The component height (of the crank housing) is denoted by the reference numeral H. It may be clearly identified that in this connection all bearing points of the land core are located outside of the subsequent cast part.

(11) The possible position of a further retaining surface in an alternative embodiment of a land core is denoted by the reference numeral 37. In this embodiment, for example, only the left-hand arrangement portions might be present, whilst the land core in the right-hand region might be directly supported via the retaining surface 37 on a cooling-duct core of a water jacket core.

(12) FIG. 5 finally shows a further embodiment of a land core 30 in a plan view, comprising two arrangement portions 34 which extend in pairs away from a cooling duct portion 32. A further arrangement portion 34 is configured opposite so that a three-point bearing is produced.

(13) FIG. 6 shows a further embodiment of a land core 30 with a three-point bearing, wherein the arrangement thereof in a water jacket 24 of a water jacket core 20 is shown in the upper image half. The focus in this embodiment is the configuration of a retaining surface 37 as a front projection which engages in a correspondingly configured rear projection in the water jacket 24. The lower view shows a plan view of the land core 30, wherein the very narrow structure thereof is clearly visible. By the positive connection and/or the coupling to the water jacket 24 a very secure arrangement and/or pre-centering is nevertheless implemented. Moreover, the features from the above Figures are disclosed.

LIST OF REFERENCE CHARACTERS

(14) 20 Water jacket core 22 Frame core 24 Cooling duct core 30 Land core 32 Cooling duct portion 34 Arrangement portion 36 Retaining surface 37 Retaining surface, front projection 38 Support element 39 Core bearing, core print 40 Vertical arrangement surface L Longitudinal axis H Component limit, component height

(15) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.