Patent Application
20230092300
This application claims benefit to European Patent Application No. EP 21 197 908.3, filed on Sep. 21, 2021, which is hereby incorporated by reference herein.
The present disclosure relates to a diecasting tool.
Cooled motor housings have an outer lateral surface as well as an inner lateral surface, between which an encircling gap is formed, which serves for cooling or in which the cooling medium circulates.
Diecastig tools can have parts inserted for encapsulation.
DE 199 43 247 C1 discloses a diecasting mould in which an insert is partially encapsulated. The insert is a compact, workpiece of solid design which is inserted into the mould and positioned in the mould by means of a presser.
DE 100 54 330 discloses a method for producing a composite casting which is designed as an end shield.
The disadvantage of the prior art is that only solid parts can be cast in, and there is no knowledge of producing a cooled motor housing by diecasting, or there are no diecasting tools which enable thin-walled, concentrically extending walls to be produced without using a further process step after casting.
In an embodiment, the present invention provides a diecasting tool that has an insert for producing a cooled motor housing. The diecasting tool has mould halves including: a stationary mould half; and movable mould half. One of the mould halves has a cylindrically extending annular gap having a central axis. The moveable mould half is arranged so as to be movable parallel to the central axis. The insert is arranged in the cylindrically extending annular gap. The insert is a bush. One end of the bush projects into a mould cavity, which is formed by the stationary mould half and the movable mould half, and is at least partially surrounded in a form-fitting manner by the casting material in a state when the casting material is cast.
Subject matter of the present disclosure will be described in even greater detail below based on the exemplary figures. All features described and/or illustrated herein can be used alone or combined in different combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the attached drawings, which illustrate the following:
Aspects of the present disclosure relate to a diecasting tool having an insert for producing a cooled motor housing, preferably an electric motor housing, and to the production method for a cooled motor housing, and to the use of the diecasting tool to produce a cooled motor housing, comprising at least one stationary mould half and at least one movable mould half, wherein one of the two mould halves has a cylindrically extending annular gap having a central axis, wherein the movably arranged mould half is arranged so as to be movable parallel to the central axis.
Aspects of the present disclosure provide a diecasting tool and its application for the production of a cooled motor housing, as well as a production method in which no further method steps are required for the installation of an inner wall in a cooled motor housing, or a cooled motor housing can be produced in one method step.
Aspects of the present disclosure take advantage of having an insert arranged in the cylindrically extending annular gap, wherein the insert is designed as a thin-walled bush, and wherein one end of the bush projects into a mould cavity, which is formed by the stationary and the movable mould halves, and is at least partially surrounded in a form-fitting manner by the casting material when the casting material is cast. The bush preferably extends over the entire length of the annular gap.
The diecasting tool according to an aspect of the present disclosure for producing a cooled motor housing, preferably an electric motor housing, comprises at least one stationary mould half and at least one movable mould half.
A cooled motor housing has an inner and an outer lateral surface, between which an encircling gap is formed in which the cooling medium circulates. With the aid of the diecasting tool according to an aspect of the present disclosure, the production of such a housing with two thin-walled, concentrically arranged, cylindrical walls is made possible.
One of the two mould halves has a cylindrically extending annular gap having a central axis, wherein the movably arranged mould half is arranged so as to be movable parallel to the central axis. An insert is arranged in the cylindrically extending annular gap, wherein the insert is designed as a bush. The bush is of thin-walled design and serves to form the inner lateral surface of a cooled motor housing. One end of the bush projects into the mould cavity, which is formed by the stationary and the movable mould halves, and is at least partially surrounded in a form-fitting manner by the casting material when the casting material is cast.
The bush preferably has a chamfer running around the outer diameter. The chamfer of the bush rests against a chamfer in one of the mould halves, as a result of which the cylindrically extending annular gap is sealed. A situation where casting material flows into the annular gap and is arranged on the lateral surface of the bush is thereby avoided.
The bush has a thickened portion of the wall at least at one end, wherein the thickened portion preferably forms at least one partially encircling collar. That is to say that the bush has an increase in wall thickness over a certain length at at least one end. The thickened portion of the wall need not extend over the entire circumference but, in a preferred embodiment, the thickened wall portion extends over the entire circumference. The thickened wall portion projects into the mould cavity arranged at the end, wherein the mould cavity is formed by the stationary and the movable mould halves, and the thickened wall portion is at least partially surrounded in a form-fitting manner by the casting material when the casting material is cast. The mould cavity arranged at the end with the thickened wall portion of the bush projecting into it forms the mould cavity for the one end of the motor housing, which is then formed at least as a partially closed end by the inflowing casting material. Alternatively, the bush has a partial base at at least one end, wherein the partial base projects into the mould cavity. Here, too, the mould cavity, which is arranged at the end, with the inwardly projecting partial base of the bush then forms one end of the motor housing.
It has been found to be advantageous if the one-piece, thin-walled bush is formed from a thickened wall portion arranged at one end or from a partial base and a lateral surface, wherein a chamfer is arranged in the transition between the thickened portion and the lateral surface or between the partial base and the lateral surface, wherein the chamfer serves to seal the cylindrically extending annular gap.
The preferably metallic, thin-walled bush serves to form the inner lateral surface of the motor housing and is connected in a form-fitting manner to the remaining part of the motor housing or is encapsulated therein by the at least partial encapsulation of the thickened wall portion or of the partial base, as a result of which the motor housing is of one-piece design while containing two different materials. On the one hand, a casting material, preferably a light metal alloy, such as an aluminium or magnesium alloy, and a pressed material, preferably consisting of a light metal alloy, such as an aluminium or magnesium alloy. It has proven to be particularly preferred if the materials of the casting and pressed material have the same material basis, that is to say if the casting and pressed material are each produced from an aluminium alloy or magnesium alloy. The chamfer ensures that no casting material runs into the annular gap or no casting material adheres to the lateral surface of the insert or of the bush.
According to a preferred embodiment, the cylindrically extending annular gap has an encircling chamfer at the open end in the mould half. The annular gap is preferably arranged in the movable mould half, facilitating the insertion of the bush. In addition to the sealing function, the chamfer also permits optimum centring of the bush, which has the corresponding chamfer.
It is advantageous if the encircling chamfer on the annular gap corresponds to the chamfer on the bush, and as a result the annular gap is tightly closed and no casting material flows into the annular gap. As a result of the sealing, a sufficiently large tolerance can be provided between the bush or the wall thickness of the lateral surface and the annular gap width, and, on the one hand, this facilitates insertion and, on the other hand, during casting, allows a certain distortion of the bush, while the bush nevertheless remains removable from the mould. Moreover, optimum sealing by means of obliquely arranged surfaces or chamfers permits optimum centring of the bush in the annular gap.
For the purpose of forming the housing lateral surface, it has proven advantageous for the diecasting tool according to an aspect of the present disclosure to have a mould cavity which is arranged so as to be offset concentrically outwards with respect to the annular gap. To form the housing lateral surface, this mould cavity is preferably formed with the aid of slides and at least one mould half. This makes it possible to apply a rib pattern or screw-on lugs or other reinforcements to the housing in accordance with requirements.
The mould cavity for forming the housing lateral surface, the cylindrical annular gap and the bush arranged therein preferably extend over the same length. That is to say that the inner and outer lateral surfaces of the cooled motor housing have the same length or end flush or at the same level at the opposite end of the thickened wall portion or of the partial base.
It has also been found to be a preferred embodiment if the diecasting tool has a plurality of slides. This makes it possible to apply a rib pattern or screw-on lugs or other reinforcements to the housing in accordance with requirements.
It has been found to be a preferred embodiment if the bush has at least two encircling chamfers, wherein the chamfers are aligned mirror-image fashion and correspond to the chamfers in the diecasting tool or rest in a sealing manner against the diecasting tool. As a result of the mirror-image alignment or the slope of the chamfers in the different directions, the bush is optimally centered and sealed at at least two points.
The bush with a partial base preferably has ribs on the underside of the partial base for stiffening the latter. In addition, the ribs transmit the torque produced by the electric motor to the cast outer lateral surface of the housing. It is advantageous if the ribs are aligned radially outwards at regular intervals from the center.
Advantages of embodiments implemented according to aspects of the present disclosure are achieved by the fact that the annular gap is sealed by a chamfer on the insert and by a corresponding chamfer on the annular gap and remains free of casting material.
The method according to an aspect of the present disclosure for producing a cooled motor housing, preferably an electric motor housing, from a light metal composite casting material, comprises the following steps:
It is advantageous if the bush is inserted into the annular gap in one mould half in such a way that the thickened wall portion arranged at one end of the bush or the partial base projects into a mould cavity which forms one side of the motor housing or the shape of the end of the motor housing which is filled with casting material and which forms one end of the motor housing.
The casting material preferably flows via a gate provided for this purpose into the diecasting mould, the gate adjoining the end of the motor housing, which is at least partially closed.
It is advantageous if the bush is inserted into the movably arranged mould half. This facilitates accessibility and insertion of the bush.
Advantages of embodiments implemented according to aspects of the present disclosure are achieved by the fact that the cooled motor housing has an inner lateral surface, wherein the inner lateral surface is formed by a cast-in insert, wherein the insert is designed as a thin-walled hollow cylinder.
The use according to an aspect of the present disclosure of the diecasting mould serves for the production of a cooled motor housing, wherein the cooled motor housing has an inner lateral surface, wherein the inner lateral surface is formed by a cast-in bush, wherein the bush is of thin-walled design.
A cooled motor housing according to an aspect of the present disclosure has an inner and an outer lateral surface, between which an encircling gap is formed in which the cooling medium circulates. The motor housing according to an aspect of the present disclosure has two thin-walled, concentrically arranged, cylindrical walls which each form the inner and outer lateral surface of the housing.
It is advantageous if the motor housing bush which serves to form the inner lateral surface consists of a metallic material, preferably aluminium or magnesium or an aluminium or magnesium sheet corresponding to the casting alloy used, as already mentioned above. The outer lateral surface is formed by the casting material and is preferably made of a light metal alloy, preferably an aluminium or magnesium alloy.
The cooled motor housing according to an aspect of the present disclosure is preferably designed as a light metal composite casting. Thus, in addition to the light metal casting material, it also consists of a further metallic material, preferably a light metal, which has already been inserted into the diecasting tool and is surrounded by the light metal casting material in such a way that the cooled motor housing is formed as a one-piece light metal composite casting.
Furthermore, it is advantageous if the inner and outer lateral surfaces extend over the same length.
All design options can be freely combined with one another, both the features of the diecasting tool, the method and its use for producing the cooled motor housing.
An exemplary embodiment of the present disclosure is described with reference to the figures, wherein the present disclosure is not limited to the exemplary embodiment.
The drawings illustrated in
The thickened wall portion 6 of the wall of the bush preferably extends continuously along the entire circumference.
From the detail view in
The mould cavity 11 arranged in the diecasting tool 1 and extending concentrically with the annular gap 4 forms the mould for the outer housing lateral surface or the outer wall 17 of the motor housing. To enable the cooled motor housing 12 to be removed from the mould, the diecasting tool 1 preferably has slides 15. The gate 14 of the diecasting tool 1 is preferably arranged on the side of the mould cavity 9 which forms the end of the partially closed motor housing 12.
While subject matter of the present disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Any statement made herein characterizing the invention is also to be considered illustrative or exemplary and not restrictive as the invention is defined by the claims. It will be understood that changes and modifications may be made, by those of ordinary skill in the art, within the scope of the following claims, which may include any combination of features from different embodiments described above.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21 197 908.3 | Sep 2021 | EP | regional |
