EP3401037A1 - Mold for producing a casting core - Google Patents

Abstract

A mold for producing a casting core (1), which is a casting technique for imaging coolant channels (2) as well as coolant inflows and outflows of a cooling jacket of an electric motor, having a core mold space which can be filled with core material and which is substantially cylindrical around a central axis (A), and whose outer wall is formed by an outer shape and the inner wall by a fully enclosed by the outer shape of the inner mold (10). In order to enable the molding of a casting core, which images the coolant channels as well as coolant inflows and outflows of the cooling jacket of an electric motor, and which can be demolded well and non-destructively after molding, components of the inner mold (10) are:
- Two first shell molds (11) and two second shell molds (13), all four together define the inner wall of the core mold space, wherein the second shell molds (13) are each arranged between the first shell molds (11),
a first demolding mechanism, which is arranged between the first shell molds (11) and adapted to move them towards each other,
- A second demolding mechanism, which is arranged between the second shell molds (13) and adapted to move them toward each other.

Description

The invention relates to a mold for producing a casting core, which is a casting technique for imaging coolant channels as well as coolant inflows and outflows of a cooling jacket of an electric motor.

The efficiency of modern electric motors and especially of electric motors, which serve the drive of vehicles depends heavily on the cooling of the electric motor. Frequently, such electric motors are therefore provided with a cooling jacket with coolant channels extending therein, which are cooled by a cooling fluid, for. As water flows through.

Because of the complexity of the shape of the coolant channels, the z. B. meandering, the production of the cooling jacket may be useful in a casting process. However, this type of production requires a suitable casting core, which must be placed within the mold, in order to image the coolant channels and also the necessary coolant inflows and outflows. In accordance with the complexity of the coolant channels, the casting core required for this purpose is also relatively complex.

The aim is therefore to enable the molding of a casting core, which images the coolant channels and coolant inflows and outflows of the cooling jacket of an electric motor, and which can be demolded well and non-destructively after molding.

• zwei erste Formschalen und zwei zweite Formschalen, die alle vier gemeinsam die Innenwand des Kernformraums begrenzen, wobei die zweiten Formschalen jeweils zwischen den ersten Formschalen angeordnet sind,
• ein erster Entformmechanismus, welcher zwischen den ersten Formschalen angeordnet und dazu ausgebildet ist, diese aufeinander zu zu bewegen,
• ein zweiter Entformmechanismus, welcher zwischen den zweiten Formschalen angeordnet und dazu ausgebildet ist, diese aufeinander zu zu bewegen.

It is therefore proposed a mold for producing a casting core, which forms coolant ducts and coolant inflows and outflows of a cooling jacket of an electric motor with a core mold space which can be filled with core material and which is substantially cylindrical around a central axis. The outer wall of the core mold cavity is formed by an outer mold, and the inner wall by a fully enclosed by the outer mold inner mold. Components of the inner form are:

• two first shell molds and two second shell molds, all of which together bound the inner wall of the core mold cavity, wherein the second mold pan are each arranged between the first mold pan,
• a first demolding mechanism, which is arranged between the first shell molds and adapted to move them towards each other,
• a second Entformmechanismus, which is arranged between the second shell molds and adapted to move them toward each other.

With such a shape, it is possible to produce complex, cylindrical casting cores, which can be used as casting technology for imaging coolant channels as well as coolant inflows and outflows of the cooling jacket of an electric motor. In its interior, such a cooling jacket typically has meander-shaped coolant channels, which in total combine to form a substantially cylindrical shape. Accordingly, the core mold space filled with core material in manufacturing the casting core is primarily determined by an outer shape and an inner shape. The outer mold forms the outer wall of the core mold cavity, and the inner mold forms the inner wall of the core mold cavity. The cylindrical inner shape is enclosed over its entire circumference by the cylindrical outer shape.

Components of the inner mold are two first mold shells and two second mold shells, wherein all four mold shells together form and define the inner wall of the core mold cavity, and wherein the second mold shells are each movably arranged between the first mold shells.

Part of the inner mold is a first demolding mechanism, which is arranged between the first shell molds and adapted to move them toward each other. Part of the inner mold is also a second demolding mechanism, which is arranged between the second shell molds and adapted to move these second shell molds toward each other.

Thus, it is a movement achieved by the two Entformmechaniken inward to the longitudinal axis of the inner mold through which is opened or released during demolding of the core mold space.

With regard to the first demolding mechanism is proposed that this comprises a longitudinally movably arranged in the direction of the central axis tray carrier with two guides arranged thereon, wherein on one guide the one, and on the other guide the other of the two first shell molds is slidably mounted, and wherein the longitudinal directions of these two guides converge towards each other. Converging means that the virtual axes of the two longitudinal directions meet at a point outside the shell carrier.

With regard to the second demolding mechanism is proposed that this comprises a longitudinally movably arranged in the direction of the central axis shell carrier with two guides arranged thereon, wherein on the one guide, the one and on the other guide, the other of the two second shell molds is slidably mounted, and wherein the longitudinal directions of these two guides converge towards each other. Converging means that the virtual axes of the two longitudinal directions meet at a point outside the shell carrier.

Preferably, the two shell carrier are longitudinally movable in the direction of the central axis to each other, for. B. by the one shell carrier is slidably disposed in the other shell carrier.

To come to the inner mold by a single, continuous drive movement to a complete demolding, the guides on the one shell carrier and the guides on the other shell carrier are each aligned so that they converge in the same direction or both diverge in the opposite direction.

So that only the pair of first shell molds and only later retracts the pair of second shell molds inward by a single, continuous drive movement, stops are formed on the shell carriers, which limit the mutual longitudinal mobility of the shell carrier at least in the direction opposite the convergence of the guides.

In order to build the two mechanisms that withdraw the mold shell pairs for demolding, compact and space-saving, one of the shell carrier including the guides arranged on it is integrally formed, however, the other shell carrier including the arranged on him two-piece two guides in the direction of formed central axis successively arranged support portions. In this case, the division of the guide arranged on the other shell carrier is such that guide sections are provided on each of the carrier sections, the guide sections being aligned with one another.

Preferably, the integrally formed shell carrier is divided by a longitudinal slot into two segments, and the segments are connected to each other only via webs.

According to a further embodiment of the form, one of the shell carriers has a frustoconical basic shape, and the other shell carrier a basic shape of a cylinder and radially projecting from the cylinder arms. The cylinder is longitudinally guided in the other, ie the frustoconical shell carrier. This contributes to a nested and thus compact construction of the two mechanisms that pull back the pair of shell molds during demolding.

According to a further embodiment of the form, the guides are of T-shaped cross section, and they engage in grooves provided with corresponding undercuts on the inner sides of the respective shell molds.

Finally, it is proposed that the facing inner sides of the first shell molds forming the first shell molds successively each have an end portion, a central portion and another end portion, and that the inner sides on the central portion in comparison to the two end portions to form a recess jump back.

Fig. 1

in perspektivischer Darstellung nur das mittels der hier beschriebenen Form herstellbare Produkt, nämlich ein Gießkern, der Kühlmittelkanäle sowie Kühlmittelzu- und -abflüsse des Kühlmantels eines Elektromotors gießtechnisch abbildet;

Fig. 2

in perspektivischer Darstellung die komplette Form zum Herstellen des in Fig. 1 illustrierten Gießkerns;

Fig. 3

ebenfalls die Form, jedoch im Vergleich zu Fig. 2 ohne die Bestandteile der Außenform;

Fig. 4

eine Stirnansicht auf die Formschalenpaare der Innenform, und zwar in der Betriebsstellung maximaler Entformung;

Fig. 4a

den Bereich IV der Fig. 4 in einer vergrößerten Darstellung;

Fig. 5

in perspektivischer Einzeldarstellung nur einen ersten Schalenträger der Innenform;

Fig. 6

in perspektivischer Einzeldarstellung nur einen zweiten Schalenträger der Innenform;

Fig. 7

die beiden ineinandergesetzten Schalenträger, und zwar in der Formstellung;

Fig. 8

im rechten Bildteil die beiden ineinandergesetzten Schalenträger in der Betriebsstellung maximaler Entformung;

Fig. 9a

die Form in einer Betriebsstellung, in der nur die beiden zweiten Formschalen entformt sind;

Fig. 9b

dieselben Gegenstände in einer fortgeschrittenen Betriebsstellung, in der auch die beiden ersten Formschalen entformt sind, und

Fig. 10

eine Stirnansicht auf alle Formschalen in der Betriebsstellung nach Fig. 9b.

Further details and advantages will become apparent from the following description of a mold for producing a casting core. For this purpose, reference is made to the drawings. Show in it

Fig. 1

in a perspective view only the producible by means of the form described herein product, namely a casting core, the coolant channels and coolant inflows and outflows of the cooling jacket of an electric motor by casting technology maps;

Fig. 2

in perspective the complete form for producing the in Fig. 1 illustrated casting core;

Fig. 3

also the shape, but in comparison to Fig. 2 without the components of the outer shape;

Fig. 4

an end view of the mold shell pairs of the inner mold, in the operating position maximum removal;

Fig. 4a

the area IV the Fig. 4 in an enlarged view;

Fig. 5

in perspective detail only a first shell carrier of the inner mold;

Fig. 6

in perspective detail only a second shell carrier of the inner mold;

Fig. 7

the two nested tray carriers, in the mold position;

Fig. 8

in the right-hand part of the picture, the two shell carriers placed in one another in the operating position of maximum demoulding;

Fig. 9a

the mold in an operating position in which only the two second shell molds are removed from the mold;

Fig. 9b

the same objects in an advanced operating position, in which the two first shell molds are removed, and

Fig. 10

an end view of all mold shells in the operating position after Fig. 9b ,

In Fig. 1 a casting mold consisting of foundry core 1 is reproduced. The casting core 1 serves to image coolant ducts 2, a coolant inflow 3 and a coolant outflow 4 of a cooling jacket of an electric motor by casting. Therefore, if the casting core 1 is placed inside a casting mold, it defines those regions where the coolant channels 2, the coolant inlet 3 and the coolant outlet 4 are located after completion of the casting.

Because of the complexity of the shape of the coolant channels 2, according to Fig. 1 are designed meandering, the production of the cooling jacket used for the electric motor is useful in a casting process.

In the following, a form is proposed with which the casting core 1 can be produced, with the aim above all of good and non-destructive demoulding.

In Fig. 2 the form designed according to the invention is reproduced in its entirety. It consists of an outer mold 9 and an inner mold 10, which are both arranged around a central axis A around. The core shape space, whose shape is in Fig. 1 is reproduced on the basis of the generated object (casting core) is accordingly also designed substantially cylindrical. The outer wall of the core mold space is formed by the outer mold 9, and the inner wall of the core mold space by the inner mold 10. Not shown openings can be the core material, for. As a casting sand, fill in the core mold cavity in which the casting sand then solidified to the casting core.

According to Fig. 2 the outer mold 9 is composed of a total of four segments, of which each segment extends approximately over a quarter circle. During demoulding, the four segments are moved radially outward, whereby then the produced casting core 1 is exposed on its outer side.

The demolding of the inner mold 10, however, is not feasible by a simple radial movement of individual segments, since they would collide with each other in their movement inwardly to the longitudinal axis A.

Although according to Fig. 4 also part of the inner mold 10 four segments, which complement each other to a cylinder and form on their outer sides of the inner wall of the core mold cavity. However, the four segments are not of uniform size and shape. Instead, two segments are formed as first shell molds 11, and two further segments as second shell molds 13. All four shell molds 11, 13 together define the inner wall of the core mold cavity, with the second mold pan 13 each being disposed between the first mold pan 11. Since the second mold shells 13 are each arranged between the first mold shells 11, both second mold shells 13 can be moved inwards towards the central axis A of the inner mold 10, without abutting against the first two mold shells 11.

In Fig. 4 and Fig. 4a is the consequence of this different design on the one hand, the shell molds 11 and the other hand, the shell molds reproduced 13: The two second shell molds 13 are here moved radially inward, but are still between the first shell molds 11. At the same time, the first shell molds 11, where in the operating position Fig. 4 the circumferentially facing edges of the second shell molds 13, each provided with a recess 17.

According to Fig. 4a the recesses 17 in the first shell molds 11 are achieved in that the mutually facing inner sides of the two first shell molds 11 successively each have an end portion 18a, a central portion 19 and a further end portion 18b. The inner sides of the first shell molds 11 jump back on the central portion 19 as compared to the two end portions 18 a, 18 b, forming the recess 17, respectively. This is in Fig. 4a additionally illustrated by the fact that in dashed lines and one of the two second shell molds 13 is outlined.

Furthermore, let the FIGS. 4 and 10 , which reproduce the pairs of shell molds 11, 13 respectively in the operating position of maximum removal from the mold, recognize the different circumferential size on the one hand of the shell molds 11 and on the other hand of the shell molds 13. The first shell molds 11 each extend over a larger circumferential angle than the second shell molds 13. For example, the first shell molds 11 each extend over a circumferential angle of 100 °, whereas the second shell molds 13 each only over a circumferential angle of 80 °.

Components of the inner mold 10 are also two demolding mechanisms, through which the shell molds 11, 13 can be moved in the direction of the central axis A. A first demolding mechanism is arranged between the first mold shells 11 and designed to move these first mold shells 11 towards each other. Similarly, a second demolding mechanism between the second shell molds 13 is arranged and adapted to move the second shell molds 13 toward each other.

In both cases, the mechanism is an oblique guidance of the two shell molds on a shell carrier. Overall, two shell carriers are available. Fig. 5 is the here two-piece constructed first shell carrier 20 again, and Fig. 6 the one-piece designed second tray carrier 30. Die Fig. 7 shows the two shell carrier 20, 30 in nereinergesetztem state. This is at the same time the operating position during the molding process.

The first shell carrier 20 has a basic shape composed of a central cylinder 21 and four radially projecting arms 22. The cylinder 21 is of such size that it can slide substantially free of play in a cylindrical opening 24, with which the second shell carrier 30 is provided.

At the outer ends of the four arms 22 guides 25A, 25B are formed. The guides 25A, 25B are each of T-shaped cross section and designed to be in undercut grooves 26 slide on the inner sides of the first shell mold 11 without play.

Thus, the two shell carrier 20, 30, as in Fig. 7 reproduced, are mounted in each other, the first shell carrier 20 is formed in two parts of two in the direction of the axis A successively arranged support portions 20A, 20B. The support portion 20A includes the cylinder 21 and the two radially projecting arms, on which the two guide portions 25A are located. The other, in comparison shorter trained support portion 20B comprises the two other arms 22, at the ends of the two guide portions 25B are formed.

The design of the first shell carrier 20 is such that the guide sections 25A and 25B arranged on the same side of the axis A are aligned with each other, and therefore together form a guide 25 interrupted in a central section. The guide 25 composed on the one side of the axis A of the guide portions 25A and 25B, and the guide 25 composed of the guide portions 25A and 25B on the other side of the axis A each extend obliquely to the axis A and converge with each other in Fig. 5 which illustrates the direction of the guide 25, dashed line.

The in Fig. 6 reproduced second shell carrier 30 has a frustoconical basic shape. At its with respect to the central axis A opposite sides of each guide 35 of T-shaped cross-section are formed, which engage in grooves 36 on the second shell molds 13 slidably. For this purpose, the grooves 36 are provided on the second shell molds 13 with corresponding undercuts.

The frusto-conical shell carrier 30 has centrally the cylindrical opening 24, in which the cylinder 21 of the other shell carrier 20 is mounted longitudinally movable.

The shell support 30 is integrally formed and is divided by a the arms 22 space bidding longitudinal slot 38 into two substantially semi-conical segments, said segments are connected to each other only two webs 39. At the end of each longitudinal slot 38 is a stop 37. The corresponding counter-stop 27 is located at the two longer arms 22 of the first shell carrier 20. The formed on the shell carrier 30 stops 37 limit together with the formed on the shell support 20 stops 27, the mutual longitudinal mobility of the Shell carrier 30, 20 in the converging of the guides 35, 25 opposite direction.

The FIGS. 9a and 9b illustrate, in two different operating positions, the operation of the two demolding mechanisms:
In the operating position according to Fig. 9a is moved by a longitudinal movement of the second shell carrier 30 in the direction of the central axis A, each of the two second shell molds 13 inward. The first two shell molds 11 do not perform any inward movement at this time.

In the operating position Fig. 9b the second shell carrier 30 is further moved along the axis A, wherein it has already come to a abutment of the stopper 37 against the stop 27. As soon as these abutments abut each other, the shell carrier 20 is taken along by the longitudinal movement of the shell carrier 30, so that henceforth both shell carriers 20, 30 move together in the direction of the central axis A. As soon as the first shell carrier 20 moves in the longitudinal direction, it moves on its guides 25, the first shell molds 11 inwards, so that these peripheral areas are removed from the mold.

Overall, so the demolding takes place in two stages (first, the second shell molds 13, then only the first shell molds 11), but by means of a single, preferably continuously performed drive movement. This drive movement is achieved by a continuous longitudinal movement of the second shell carrier 30, which automatically entrains the first shell carrier 20 after a certain longitudinal travel.

Materials for the inner mold 10 may be plastic, metal or wood.

Suitable core material of the foundry core 1 are sand or free-flowing oxidic substances or substance mixtures which contain inorganic or organic binders, these substances or mixtures of substances curing either thermally and / or chemically.

LIST OF REFERENCE NUMBERS

1

casting core

2

Coolant channel

3

coolant supply

4

Coolant outflow

9

external form

10

interior shape

11

first shape shell

13

second mold shell

17

recess

18a

end

18b

end

19

midsection

20

first tray carrier

20A

support section

20B

support section

21

cylinder

22

poor

24

opening

25

guide

25A

guide section

25B

guide section

26

groove

27

attack

30

second shell carrier

35

guide

36

groove

37

attack

38

longitudinal slot

39

web

A

central axis, longitudinal axis

Claims (12)

A mold for producing a casting core (1), which images cooling medium channels (2) as well as coolant inflows and outflows (3, 4) of a cooling jacket of an electric motor with a core molding space that can be filled with core material, essentially around a central axis (A) is cylindrical, and whose outer wall is formed by an outer mold (9) and its inner wall by a fully enclosed by the outer mold inner mold (10), wherein components of the inner mold (10) are: - Two first shell molds (11) and two second shell molds (13), all four together define the inner wall of the core mold space, wherein the second shell molds (13) are each arranged between the first shell molds (11), a first demolding mechanism, which is arranged between the first shell molds (11) and adapted to move them towards each other, - A second demolding mechanism, which is arranged between the second shell molds (13) and adapted to move them toward each other. Mold according to claim 1, characterized in that the first demolding mechanism comprises a longitudinally movably arranged in the direction of the axis (A) tray carrier (20) with two guides arranged thereon (25), wherein on one guide the one, and on the other guide the another of the two first shell molds (11) is slidably mounted, and wherein the longitudinal directions of the two guides (25) converge towards each other. Mold according to claim 1 or 2, characterized in that the second demolding mechanism comprises a longitudinally movably arranged in the direction of the axis (A) shell carrier (30) with two guides arranged thereon (35), wherein on the one guide, the one, and on the other Guide the other of the two second shell molds (13) is slidably mounted, and wherein the longitudinal directions of the two guides (35) converge to each other. Mold according to claim 2 in combination with claim 3, characterized in that the two shell carriers (20, 30) in the direction of the axis (A) are longitudinally movable relative to each other. A mold according to claim 4, characterized in that the guides (35) on the tray carrier (30) and the guides (25) on the other tray carrier (20) converge in the same direction. A mold according to claim 4 or 5, characterized by stops (37, 27) formed on the shell carriers (30, 20), which control the mutual longitudinal mobility of the shell carriers (30, 20) at least in the opposite direction to the convergence of the guides (35, 25) limit. A mold according to claim 2 in combination with claim 3, characterized in that one of the tray carriers (30) including the guides (35) arranged on it is formed in one piece, and that the other tray carrier (20) including the guides (25) arranged on it two parts of two in the direction of the axis (A) arranged behind one another support portions (20A, 20B) is formed. Mold according to claim 7, characterized by a division at the other bowl support (20) disposed guide (25) such that the guide portions (25A, 25B) on each of the support portions (20A, 20B) are provided, wherein the guide portions (25A) of the a support portion are aligned with the guide portions (25B) of the other support portion. Mold according to claim 7 or 8, characterized in that the integrally formed shell carrier (30) is divided by a longitudinal slot (38) into two segments, and that the segments are interconnected only by webs (39). Mold according to one of claims 4 - 9, characterized in that one of the shell supports (30) has a frusto-conical basic shape, that the other shell support (20) has a basic shape composed of a cylinder and radially projecting arms therefrom, and in that the cylinder frustoconical shell carrier (30) is longitudinally guided. Mold according to one of claims 4 - 10, characterized in that the guides (35, 25) of T-shaped cross-section and are in undercut shaped grooves (36, 26) on the inner sides of the respective mold shells (13 and 11) engage. Mold according to one of the preceding claims, characterized in that the mutually facing inner sides of the two first shell molds (11) successively each have an end portion (18a), a central portion (19) and a further end portion (18b), and that the inner sides on the Central portion (19) compared to the two end portions (18 a, 18 b) to form a recess (17) jump back.

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