阅读说明：本技术 用于制造增强型双金属铸造复合件的方法及设备 (Method and apparatus for manufacturing reinforced bimetallic casting composites ) 是由 伊万·比卡里奥 伊尼戈·阿朗古伦 于 2019-06-27 设计创作，主要内容包括：提供一种用于制造增强型双金属铸造复合件的方法,其包括以下步骤：提供处于预成形状态的至少一个金属嵌入件；将处于预成形状态的至少一个金属嵌入件引入模具中；将处于预成形状态的至少一个金属嵌入件保持在模具中的预定位置中；借助于闭合元件执行模具的闭合操作；执行变形操作,借助于变形操作,将处于预成形状态的至少一个金属嵌入件从预成形状态变形至铸造状态；执行金属包覆铸造步骤,包覆铸造金属至少部分地铸造在处于预成形状态的至少一个金属嵌入件上；使包覆铸造金属凝固；以及将至少一个金属嵌入件与包覆铸造金属一起从模具中取出。还提供了用于制造增强型双金属铸造复合件、特别是用于执行所述方法的设备。(A method for manufacturing a reinforced bimetallic casting composite is provided, comprising the steps of: providing at least one metal insert in a preformed state; introducing at least one metal insert in a preformed state into a mold; holding at least one metal insert in a preformed state in a predetermined position in a mold; performing a closing operation of the mould by means of the closing element; performing a deforming operation by means of which the at least one metallic insert in the preformed state is deformed from the preformed state to the cast state; performing a metal overcasting step, the overcasting metal being at least partially cast onto the at least one metal insert in a preformed state; solidifying the clad cast metal; and removing the at least one metal insert from the mold with the overcast metal. Apparatus for manufacturing reinforced bimetallic casting composites, particularly for performing the method, is also provided.)

1. A method for manufacturing an enhanced bimetallic casting composite, wherein at least one metallic insert (2) is provided in a mould (3) and a metallic overcasting step is performed, wherein an overcasting metal (14) is at least partially cast on the at least one metallic insert (2) by means of the metallic overcasting step,

characterized in that the method comprises the following steps:

a) -providing said at least one metal insert (2) in a preformed state;

b) introducing the at least one metallic insert (2) in its preformed state into the mould (3);

c) -retaining said at least one metallic insert (2) in its preformed state in a predetermined position in said mould (3);

d) -performing a closing operation of the mould by means of a closing element (9);

e) -performing a deformation operation, wherein the at least one metallic insert (2) in its preformed state is deformed from its preformed state to its cast state by means of the deformation operation;

f) -performing said metal overcasting step, wherein said overcast metal (14) is at least partially cast on said at least one metal insert (2) in its as-cast condition;

g) solidifying the clad cast metal (14); and

h) -removing said at least one metal insert (2) from said mould (3) together with said overcasting metal (14).

2. Method according to claim 1, wherein the deformation operation is performed by at least one actuator (11; 5), wherein the at least one actuator (11; 5) is a mechanical actuator, a hydraulic actuator, a pneumatic actuator, a magnetic actuator or an electric actuator.

3. Method according to claim 1 or 2, wherein the deformation operation is performed before the closing operation.

4. Method according to claim 1 or 2, wherein the deformation operation is performed after the closing operation.

5. Method according to claim 1 or 2, wherein said deformation operation is performed at least partially by means of said closing operation and a retraction and closing operation is performed after said deformation operation, wherein by means of said retraction and closing operation said closing element (9) is at least partially overturned and a further closing operation of said mould is performed.

6. Method according to claim 5, wherein the retraction and closing operation comprises a sliding movement (15) of the closing element (9) to one side substantially perpendicular to a closing direction (8) of the closing element (9).

7. Method according to claim 5, wherein said retracting and closing operation comprises a rotational movement (16) of the closing element (9) about an axis substantially parallel to the closing direction (8) of the closing element (9).

8. Method according to any one of claims 1 to 7, wherein the mould (3) is a thermally regulated mould, wherein the thermally regulated mould is capable of controlling a mould temperature, in particular different mould temperatures in different regions of the mould (3), in the range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃, in particular by means of at least one temperature sensor, and by means of at least one temperature controller, preferably a PID controller, in particular controlling a mould temperature, in particular different mould temperatures in different regions of the mould (3), in the range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃.

9. The method according to any one of claims 1 to 8, wherein during solidification of the over cast metal (14), at least one actuator element, in particular at least one squeeze pin, squeezes the over cast metal (14) while the over cast metal (14) is in a semi-solid state.

10. Method according to any one of claims 1 to 9, wherein, after step h), a finishing operation is performed on said at least one metal insert (2) together with said overcasting metal (14).

11. The method according to any one of claims 1 to 10, wherein, after removing the at least one metal insert (2) together with the overcasting metal (14) from the mould, the inner surface of the mould (3) is at least partially cleaned and at least partially sprayed with a mould release agent.

12. The method according to any one of claims 1 to 11, wherein the at least one metal insert (2) in a preformed state is provided in a preheated state.

13. Method according to any one of claims 1 to 12, wherein, prior to step a), a preforming operation is performed on said at least one metal insert (2), preferably on said at least one metal insert (2) by means of cutting, cold or hot pressing, 3D prototyping, casting or machining of said at least one metal insert (2), in order to achieve said preformed state of said at least one metal insert (2).

14. An apparatus (1) for manufacturing a reinforced bimetallic casting composite, preferably for performing the method according to any one of claims 1 to 13, the apparatus (1) comprising:

-a mould (3), wherein the mould comprises a mould cavity (4); and

-a closing element (9), the closing element (9) being movable along a closing direction (8) to close the mold cavity (4),

characterized in that the device (1) further comprises:

at least one actuator (11; 5), said at least one actuator (11; 5) being adapted to perform a deformation operation on the metal insert (2) when being arranged inside said mould cavity (4), wherein said at least one actuator (11; 5) is a mechanical, hydraulic, pneumatic, magnetic or electric actuator.

15. The apparatus (1) according to claim 14, wherein the mould (3) is a thermally regulated mould, wherein the thermally regulated mould is capable of controlling a mould temperature, in particular different mould temperatures in different regions of the mould (3), in a range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃, in particular by means of at least one temperature sensor, and by means of at least one temperature controller, preferably a PID controller, in particular to control a mould temperature, in particular different mould temperatures in different regions of the mould (3), in a range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃.

Technical Field

The present invention relates to a method for manufacturing a reinforced bi-metallic cast composite. Furthermore, the present invention relates to an apparatus for manufacturing a reinforced bimetallic casting composite.

Background

Metal casting composites are well known in the art and are used in a wide variety of applications. In particular, it is known to reinforce metal cast parts in order to improve, for example, the strength of the metal cast part to meet its ultimate intended purpose.

For example, it is known to reinforce a metal cast component by another metal component having a higher strength or alternatively having another preferred characteristic, in order to finally achieve a so-called bimetallic cast composite having a higher strength or alternatively having another preferred characteristic compared to a metal cast component without said reinforcement.

In this context, in the present patent application, a bimetallic casting composite is referred to as a reinforced bimetallic casting composite when it refers to a bimetallic casting composite manufactured by the steps of providing a first metal component and then casting metal at least partially around said first metal component in order to achieve reinforcement. In this way, a reinforced bimetallic casting composite is obtained which comprises said first metal part as an insert and which further comprises a cast second metal part at least partially surrounding said insert as an over-cast second metal part.

Several methods and apparatus for manufacturing such reinforced bimetallic casting composites are known. In GB873012A, a reinforced bimetallic casting composite is described as a brake drum or engine cylinder. The reinforced bimetallic casting composite is manufactured by two sequential casting processes. That is, in a first step, a metal insert is manufactured by centrifugal casting, and in a second step, a light metal is cast on the metal insert. Due to these two successive casting steps, the method is very time consuming and costly. That is, after the first casting step, the cast metal insert needs to be cooled, solidified and removed from the first mold before the second casting step can be achieved in the second mold in which the cast metal insert needs to be placed.

From WO9002017a1, a method is known for manufacturing an enhanced bimetallic casting composite as a valve block, wherein in a first step a cylinder is cold forged and in a subsequent step the cold forged cylinder is inserted into a mold in which metal is injection molded around the cylinder. Said first step, i.e. the formation of the pre-formed cylindrical piece, which is later molded in said second step, requires several forming operations performed by at least one further apparatus. Thus, the two steps, i.e. forming the pre-formed cylinder and injection moulding around said cylinder, require at least two different apparatuses. Thus, the method involves extensively the necessary equipment for manufacturing the reinforced bimetallic casting composite and, in addition, is very time consuming and costly.

Similar methods and apparatus for manufacturing reinforced bimetallic casting composites are known from US2014290894a1, US2004222665a1 and US2016137232a 1. It is known from said prior art to manufacture reinforced bimetal composites in at least two successive main stages. That is, in a first step, a first metal part is formed as a metal insert in a first apparatus, and then a subsequent step is provided, wherein in the subsequent step the metal insert is placed into a mold and then metal is cast at least partially around the metal insert. Thus, the at least two successive main stages, i.e. forming the metal insert in a first apparatus and casting the metal around the metal insert in a second apparatus as a mould, require at least two different apparatuses. Thus, the method involves extensively the necessary equipment for manufacturing the reinforced bimetallic casting composite and, in addition, is very time consuming and costly.

Accordingly, there is a need for a reinforced bimetallic casting composite that is less time consuming and less costly to manufacture.

Disclosure of Invention

It is an object of the present invention to provide a method for manufacturing a reinforced bimetallic casting composite, according to which the reinforced bimetallic casting composite can be manufactured in a less time consuming and less costly manner.

This object is achieved by a method for manufacturing a reinforced bimetallic casting composite according to claim 1. Advantageous embodiments are described in the claims dependent on claim 1.

Furthermore, it is an object of the present invention to provide an apparatus for manufacturing a reinforced bimetallic casting composite by means of which the reinforced bimetallic casting composite can be manufactured in a less time consuming and less costly manner.

This object is achieved by an apparatus according to claim 14 and advantageous embodiments are described in the claims referring back to claim 14.

In particular, according to the present invention, a method for manufacturing a reinforced bimetallic casting composite is provided, wherein at least one metal insert is provided in a mould and a metal overcasting step is performed, wherein an overcast metal is at least partially cast onto the at least one metal insert by means of the metal overcasting step. The method is characterized in that it comprises the following steps: a) providing the at least one metal insert in a preformed state; b) introducing the at least one metal insert in its preformed state into the mold; c) holding the at least one metal insert in its preformed state in a predetermined position in the mold; d) performing a closing operation of the mould by means of a closing element; e) performing a deforming operation, wherein the at least one metallic insert in its preformed state is deformed from its preformed state to a cast state by means of the deforming operation; f) performing the metal overcasting step, wherein the overcast metal is at least partially cast onto the at least one metal insert in its as-cast condition; g) solidification of the clad cast metal; and h) removing the at least one metal insert from the mold together with the overcasting metal.

Generally, according to the invention, the individual steps of the described method are performed in the described order, starting from step a) and proceeding to step h). However, to some extent, the order of the steps may also be modified. For example, the steps d) and e), i.e. the closing operation and the deforming operation, may be performed in an alternating order or even simultaneously. In other words, the deformation operation of the metal insert can also be carried out before or simultaneously with the closing of the mould.

As a material for the metal insert, one material may be selected from the group consisting of: steel, iron, aluminum, copper, magnesium, titanium alloys, or any alloy or combination of the mentioned metals. As the material for cladding the cast metal, one material may be selected from the following group: steel, iron, aluminum, copper, magnesium, titanium, zinc alloys, or any alloy or combination of the mentioned metals. In general, the material of the metal insert and the material of the over-cast metal may be the same. Preferably, however, a material for the metal insert is used which is different from the material for the overcast metal, such that the metal insert material has a higher melting point than the overcast metal material. In particular, the metal insert may be a metal plate, preferably a steel plate. Thus, an enhanced bimetallic casting composite may be achieved that combines the positive effects of the different materials used for the insert and the outer clad cast metal.

By preformed state of the metal insert it is meant the rough shape of the metal insert, that is, the shape that the metal insert has is different from its intended final shape that the metal insert should have when incorporated into the reinforced bimetallic casting composite to be manufactured. For example, a generally flat, flat sheet steel corresponds to the metal insert in a preformed state.

The metal insert is deformed from the preformed condition to the cast condition as a result of the deforming operation. The as-cast condition may generally correspond to the final intended shape of the metal insert that should be present in the reinforced bimetallic casting composite to be produced. Minor further modifications may still occur, for example, due to a subsequent overcasting step. Such further variations in the shape of the metal insert due to the subsequent overcasting step may also be taken into account when performing the deforming operation for shaping the metal insert into the as-cast condition. In this case, the as-cast condition of the metal insert also does not correspond exactly to the final intended shape of the metal insert in the reinforced bimetallic casting composite to be produced. However, due to the deforming operation, a significant change of the shape of the metal insert from its preformed state to its cast state is achieved. Thus, by cast condition of the metal insert it is meant the finished or near finished shape of the metal insert, i.e. the metal insert has a shape that corresponds or nearly corresponds to its intended final shape that the metal insert should have in the reinforced bimetallic casting composite to be manufactured, and which is different from the shape of the metal insert in the preformed condition. For example, the substantially flat, flat sheet steel of the metal insert in the preformed state may be deformed in the as-cast state into a no-flat metal insert comprising two shoulders at opposite ends of the metal insert, resulting in the metal insert having a U-shaped cross-section.

The deforming operation may be a stamping operation, in particular a hot deforming operation, such as hot stamping.

For the metal-clad casting step, it means a co-casting operation inside the mould, due to which molten metal is cast into the cavity (moulding cavity) of the mould. The metal insert arranged inside the mould or in particular inside the mould cavity is moulded or overmoulded by said metal overmoulding step. That is, the metal insert is at least partially in contact with the molten metal at its outer surface. Furthermore, the metal insert may be completely covered, i.e. completely overmoulded, in the metal overmoulding step. The casting operation preferably employs high pressure die casting. However, the casting machine used may also be another die casting, extrusion, semi-permanent or low-pressure casting machine. Depending on the casting process, the pressure on the metal insert varies from a few bars to about 1200 bars in high pressure die casting, and up to about 2000 bars in squeeze casting (squeeze casting).

Under solidification of the clad cast metal, the process means solidifying the cast molten metal by cooling to at least below the melting point according to solidification of the clad cast metal. The solidification according to the method may be performed passively, but may also be actively promoted, for example by actively cooling the mould. The solidification of the overcasting metal can be completed before the next step of the method, i.e. the extraction of the metal insert together with the overcasting metal from said mould (step g)). However, the next step (step g)) may be performed when solidification of the clad cast metal has not been completed. In this case, the solidification of the overcasting metal must have proceeded to such an extent as to allow the metal insert to be removed from the mould together with the overcasting metal. The step of removing the at least one metal insert from the mold with the overcasting metal typically further comprises the step of opening the mold.

According to the described method, at least one metal insert may be used and ultimately incorporated into a reinforced bimetallic casting composite as a reinforcement. However, two or more metal inserts may also be used and combined.

As a result, after the at least one metal insert and the clad cast metal are removed from the mold, the resulting product is a reinforced bimetallic casting composite as a metal matrix composite with metal inserts, such as plates. All mentioned steps of the method may be performed by one single mould. It is not necessary to use additional equipment to deform the metal insert into its final intended shape and to insert the metal insert into the overcasting metal. Thus, a method for manufacturing a reinforced bimetallic casting composite is achieved, according to which the reinforced bimetallic casting composite can be manufactured in a less time consuming and less costly manner. A reduction in space for the machine is obtained, as well as a reduction in machine and production costs and an increase in process productivity.

In a preferred embodiment, the deforming operation is performed by at least one actuator, wherein the at least one actuator is a mechanical actuator, a hydraulic actuator, a pneumatic actuator, a magnetic actuator or an electric actuator. Preferably with two or more actuators. The actuator may be arranged inside or outside the mould cavity of the mould, but in case of being arranged outside the mould cavity, the actuator forms part of the mould and is adapted to interact with the metal insert in its preformed state after being introduced into the mould cavity. The actuator performs the deformation operation of the metal insert due to its movement. The actuator may perform linear, rotational or combined motion to allow for deformation. Furthermore, the actuator may ensure the positioning of the insert in the mould. The actuator may therefore also be responsible for performing step c) of the method, i.e. maintaining the metal insert in a predetermined position in the mould. Thus, the actuator may also be a positioner at the same time. The actuator may also have a telescopic motion, i.e. the actuator may be telescopic, in order to leave sufficient space for the molten overcasting metal to flow into the mould cavity of the mould and cast around the metal insert. The actuator or positioner may be a spacer rod telescopically mounted on a spring, which presses against a deformable portion of the metal insert. Generally, the actuator may perform the deforming operation by magnetic force, adhesion, suction, vacuum, suction cup, or gravity.

In a particular embodiment, the deforming operation is performed before the closing operation. In other words, step e), i.e. the deformation operation, of the method is performed before step d), i.e. before the mould is closed.

In another particular embodiment, the deforming operation is performed after the closing operation. In other words, after step d), i.e. after the mould has been closed, step e), i.e. the deforming operation, of the method is performed.

In a particular embodiment, the deformation operation is performed at least partially by means of the closing operation, and after the deformation operation, a retraction and closing operation is performed, wherein by means of the retraction and closing operation the closing operation element is at least partially flipped and a further closing operation of the mould is performed. Thus, steps d) and e) of the method are performed more or less simultaneously. The closing operation can thus be responsible for the deformation operation of the metal insert. In case at least one actuator performs a deformation operation, the actuator may be incorporated into a closing element by means of which the closing operation is performed. The deformation operation may be performed at least partially by means of a closing operation, that is to say the deformation operation may additionally be performed by other operations, such as an actuator operation of an actuator, which is additionally arranged inside the mold cavity. In this case, the combination of the actuators of the inside of the mold cavity and of the closing operation performs the desired deformation operation. The successive retracting and closing operations are performed such that, first, the closing element is at least partially turned over again, so as to leave sufficient space for the molten overcasting metal to subsequently flow into the cavity of the mould and be cast around the metal insert. Secondly, after the closing element is at least partially turned over, it may be necessary to close the mould again to allow the successive overcasting steps to be carried out. Thanks to said particular embodiment, an efficient method is achieved, since the necessary movement of the closing operation can be combined with the necessary movement of the deforming operation, such as hot stamping. The closing force of the closing element can be effectively used to perform the deforming operation.

In a particular embodiment, the retraction and closing operation comprises a sliding movement of the closing element to one side substantially perpendicular to the closing direction of the closing element. Due to the combination of the tilting movement and the sliding movement of the closing element, sufficient space is left for the molten overcasting metal to subsequently flow into the cavity of the mould and be cast around the metal insert.

In another particular embodiment, said retracting and closing operation comprises a rotary movement of said closing element around: said axis being substantially parallel to the closing direction of said closing element. Since the turning motion of the closure member is combined with the rotational motion up to the predetermined angle, sufficient space is left for the molten clad casting metal to subsequently flow into the mold cavity of the mold and cast around the metal insert.

In a particular embodiment, the mould is a thermo-regulated mould, wherein the thermo-regulated mould can control the mould temperature, in particular the different mould temperatures in different zones of the mould, within the range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃, in particular by means of at least one temperature sensor and by means of at least one temperature controller, preferably a PID controller, to control the mould temperature, in particular the different mould temperatures in different zones of the mould, within the range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃. Preferably, the mould may be heated, in particular unequally in different regions or zones of the mould. Thus, an efficient heat transfer from the heated mould surface to the metal insert placed in the mould may be achieved. As a preparation for the deformation operation, it is preferred that different regions of the metal insert can be heated in different ways. Thus, the metal insert may be efficiently deformed from its preformed state to its cast state. Thus, providing a thermally regulated die facilitates the deformation operation of the metal insert. Moreover, the ultimate desired properties of the enhanced bimetallic casting composite may be affected by adjusting the temperature of the metal insert prior to the overcasting step, particularly by providing different temperatures to different regions of the metal insert. Preferably, each zone of the mould to be heated unequally has a single temperature sensor and a single temperature controller, preferably a PID controller, to control the temperature of the different zones in an efficient manner. To effectively maintain thermal control of the mold, a cooling system as well as a heating system may be employed in the mold. The cooling system and heating system may be cartridge heaters, spray coolers, water and oil coolers, and other temperature control systems or combinations thereof.

In another particular embodiment of the method, at least one actuator element, in particular at least one squeeze pin, squeezes the over cast metal while the over cast metal is in a semi-solid state during solidification of the over cast metal. Thus, better performance may be achieved as a final product of the reinforced bimetallic casting composite as compared to a product that has not been semi-solid extruded, due to, for example, a reduction in shrinkage porosity (shrinkage porosity) or a corresponding enhancement in the bonding of the metal insert and the clad cast metal. As at least one actuator element, it is also possible to use at least one actuator to perform the deformation operation.

In another particular embodiment of the method, after step h), the at least one metal insert is subjected to a finishing operation together with the clad cast metal. Such finishing operations after removal of the reinforced bimetallic casting composite from the mold may be, for example, a trimming operation or any other machining or finishing process. Thus, a higher quality enhanced bimetallic cast component may be achieved.

In a particular embodiment of the method, after the at least one metal insert is removed from the mold together with the overcasting metal, the inner surface of the mold is at least partially cleaned and at least partially sprayed with a release agent. Therefore, some portion of the over-cast metal may be prevented from being accumulated (stark) in the mold. This can be supported by possible temperature control of different areas inside the mould. As a result, an efficient method is achieved because the next production cycle for manufacturing the reinforced bimetallic casting composite can be initiated more quickly. The spray coating and subsequent drying processes employed after the bimetallic cast part is removed from the mold may also be employed to maintain the desired mold temperature in each portion of the mold prior to the start of a new manufacturing cycle.

In another particular embodiment, the at least one metal insert in a preformed state is provided in a preheated state. Thus, a more efficient method may be achieved, since the time for possible internal heating of the metal insert before performing the step of overmoulding of the metal insert may be reduced.

In a particular embodiment of the method, prior to step a), a preforming operation is performed on said at least one metal insert, preferably by means of cutting, cold or hot pressing, 3D prototyping, casting or machining of said at least one metal insert, in order to achieve said preformed state of said at least one metal insert. Thus, a reinforced bimetallic casting composite may be achieved that includes a metal insert that acts as a reinforcement and has an arbitrarily complex shape. The potential limitation of deforming the shape of the metal insert by the step of deforming operation can be compensated by the fact that: the final intended design of the metal insert is achieved by a combination of a preforming operation and a deforming operation.

According to another aspect of the present invention there is provided an apparatus for manufacturing an enhanced bimetallic casting composite, preferably for performing a method according to any one of claims 1 to 13, the apparatus comprising: a mold, wherein the mold comprises a mold cavity; and a closing element movable in a closing direction to close the mould cavity. The apparatus is characterized in that the apparatus further comprises: at least one actuator adapted to perform a deforming operation on a metal insert when disposed inside the mold cavity, wherein the at least one actuator is a mechanical actuator, a hydraulic actuator, a pneumatic actuator, a magnetic actuator, or an electric actuator.

Thus, an apparatus is provided by means of which a reinforced bimetallic casting composite can be manufactured with fewer machines, for example in a single machine, without the need for multiple apparatuses. It is not necessary to use a plurality of apparatuses for the necessary deformation operations and the overcasting steps of the metal inserts.

According to the description of the previous method, the actuator or actuators may be incorporated into the closing element or arranged inside or outside the moulding cavity of the mould. They are adapted to interact with a metal insert arranged inside the mould in order to perform a deformation operation on the metal insert. The advantages described previously in relation to the method are equally valid for the device according to the invention.

In a particular embodiment of the apparatus, the mold is a thermally regulated mold, wherein the thermally regulated mold can control the mold temperature, in particular the different mold temperatures in different regions of the mold, in the range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃, in particular by means of at least one temperature sensor and by means of at least one temperature controller, preferably a PID controller, to control the mold temperature, in particular the different mold temperatures in different regions of the mold, in the range of 80 ℃ to 500 ℃, preferably 200 ℃ to 400 ℃. Thus, according to the preceding description of the respective features of the method, it is possible to advantageously control the temperature of the different parts of the mould, so that the metal insert provided inside the mould cavity of the apparatus can be thermally conditioned.

The different aspects and embodiments of the invention defined above may be combined with each other as long as they are compatible with each other.

Other advantages and features of the present invention will become apparent from the following detailed description, and will be particularly pointed out in the appended claims.

Drawings

To complete the description and for a better understanding of the invention, a set of drawings is provided. The accompanying drawings, which form a part of the specification and illustrate embodiments of the invention, are not to be construed as limiting the scope of the invention, but are merely as examples of how the invention may be practiced. The drawings include the following figures:

FIG. 1 illustrates a flow chart of a method for manufacturing a reinforced bimetallic casting composite in accordance with the present invention.

Fig. 2A shows a schematic sketch representing a method and an apparatus according to the invention, wherein the method performs the steps of placing a metal insert in a mould and holding the metal insert in the mould.

Fig. 2B shows a schematic sketch corresponding to the reproduction in fig. 2A, wherein the method now performs the steps of the closing operation and the deforming operation.

Fig. 2C shows a schematic sketch corresponding to the reproduction in fig. 2A and 2B, wherein the method now performs a retracting movement of the actuator.

Fig. 2D shows a schematic sketch corresponding to the reproduction in fig. 2A, 2B and 2C, wherein the method now performs a metal overcasting step.

Fig. 2E shows a schematic sketch corresponding to the reproduction in fig. 2A, 2B, 2C and 2D, where the method now performs the steps of opening the mould and part extraction.

Fig. 3A shows a schematic sketch representing alternative steps of the method and apparatus according to the invention corresponding to the reproduction in fig. 2A to 2E with a retraction and closing operation for the closing element.

Fig. 3B shows a schematic sketch of a further alternative step corresponding to the reproduction in fig. 3A with a retraction and closing operation for the closing element.

Detailed Description

The following description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, which illustrate elements and results in accordance with the present invention.

In the following description, like reference numerals refer to like elements and corresponding like features. Therefore, the description given with respect to a specific drawing is valid also for elements in other drawings. Thereby avoiding duplicate descriptions. Furthermore, individual features described with respect to particular embodiments may also apply to different embodiments.

FIG. 1 illustrates a flow chart of a method for manufacturing a reinforced bimetallic casting composite in accordance with the present invention. In a first step I) as an optional step, a preforming of the metal insert may be performed. As material for the metal insert, the material may be selected from the group of: steel, iron, aluminum, copper, magnesium, titanium alloys, or any alloy or combination of the metals. By said preforming, for example by means of cutting, cold or hot pressing, 3D prototyping, casting or machining, a metal insert in a preformed state is provided which is intended to be integrated with the final bimetal composite.

In the following two steps, step a) and b), which are the first basic steps of the proposed method, a metal insert is provided in its preformed state and introduced into a mould. In particular, the metal insert is placed into a mold cavity of a mold, in which the metal insert is held in a predetermined state, for example by a retainer, such as a spacer bar telescopically mounted on a spring, which can be pressed against the metal insert. In general, the positioner may be adapted to perform the positioning operation by magnetic force, adhesion, extraction, vacuum, suction cup, or gravity. The metal insert may optionally be provided in a preheated state. The metal insert may be, for example, a flat steel plate.

Then, in step d), a closing operation of the mold is performed by means of the closing element, and in step e), a deforming operation is performed. Since by means of said closing operation it is ensured that a subsequent casting operation, i.e. a metal-clad casting step, can be performed, it is necessary to close the mould cavity of the mould. By means of said deformation operation, the metal insert is deformed from its preformed state to its cast state. The deforming operation may be a stamping operation, in particular a hot deforming operation such as hot stamping. The deforming operation may be performed by at least one actuator, for example by a mechanical actuator, a hydraulic actuator, a pneumatic actuator, a magnetic actuator or an electric actuator, and the deforming operation may also be performed by a positioner. In this case, the positioner corresponds to an actuator.

Said steps d) and e), i.e. the closing operation and the deforming operation, can also be performed in an interchangeable sequential manner or even simultaneously. In other words, the deformation operation of the metal insert can also be carried out before or while the mold is closed.

Subsequently, in step f), a metal clad casting step is performed. Thereby, the over-cast metal is at least partially cast onto the metal insert in the mold. The bonding between the metal insert and the clad cast metal is achieved by performing the steps described so as to ultimately obtain a reinforced bimetallic casting composite.

As the material for cladding the cast metal, a material may be selected from the group consisting of: steel, iron, aluminum, copper, magnesium, titanium, zinc alloys or any alloy or combination of said metals. In general, the material of the metal insert and the material of the over-cast metal may be the same. However, it is preferable to use a material of the metal insert different from that for the over-cast metal because the material of the metal insert has a higher melting point than that of the over-cast metal. Thus, an enhanced bimetallic casting composite may be achieved that combines the advantageous effects of different materials for the metal insert and the outer clad cast metal.

The casting operation preferably corresponds to high pressure die casting. However, the casting machine used may also be another die casting, extrusion, semi-permanent or low-pressure casting machine. Depending on the casting process, the pressure on the metal insert varies from a few bar to about 1200 bar in high-pressure die casting and to about 2000 bar in squeeze casting.

In a subsequent step g), the clad cast metal is solidified. Thereby, a bond between the metal insert and the clad cast metal is achieved. The resulting part would be the desired reinforced bimetallic casting composite. In order to improve the performance of the resulting reinforced bimetallic casting composite, the extrusion operation may be performed during step g), i.e. during solidification of the clad cast metal. In particular, at least one extrusion pin may extrude the clad cast metal when the clad cast metal is in a semi-solid state during solidification of the clad cast metal. Thus, shrinkage porosity may be reduced or the combination of metal insert and overcasting metal may be increased accordingly. As the at least one actuator element for the pressing operation, at least one of an actuator or a positioner may also be used.

In the final essential step of the method, in step h), the metal insert is removed from the mold together with the clad cast metal as a reinforced bimetallic casting composite. In this step, the mold is also opened, that is to say the closing element is opened and the closing operation of the mold is again undone.

Optionally, as described in step II) of fig. 1, the reinforced bimetallic casting composite may be subjected to a finishing operation after it is removed from the mold. For example, the reinforced bimetallic casting composite may be exposed to a finishing operation or any other machining or finishing process to further improve its performance.

Further, after removal of the reinforced bimetallic casting composite from the mold, the interior surfaces of the mold may optionally be at least partially cleaned and at least partially sprayed with a mold release agent. Thus, some parts of the clad cast metal may be avoided from building up in the mold and an efficient method is achieved, since the next production cycle for manufacturing the reinforced bimetallic casting composite may be initiated more quickly.

The mould used in the method is preferably a thermally regulated mould. Thus, the mold temperature can be controlled. In particular, different mold temperatures may be set in different regions of the mold. This can be done by heating different areas of the mould in a particularly intensive manner. The mold or different regions thereof may be heated to 500 ℃. During the method, the mold or different regions thereof preferably have a temperature in the range of 200 ℃ to 400 ℃ when the metal insert is placed in the mold. The temperature of the mould or the different zones thereof is controlled by means of a temperature sensor for each of the different mould zones and a temperature controller, preferably a PID controller. Additionally, the mold and its various mold regions may be cooled in a controlled manner. The cooling and heating systems may be cartridge heaters, spray coolers, water and oil coolers, and other temperature control systems or combinations thereof.

After performing the method as shown in fig. 1 and at least steps a) to h) as described above, the obtained product is a reinforced bimetallic cast composite as a metal matrix composite with a metal insert, e.g. a sheet. The steps mentioned may be performed by a single mould or machine. It is not necessary to use additional equipment to deform the metal insert into its final intended shape and to insert the metal insert into the overcasting metal. Thus, a method for manufacturing a reinforced bimetallic casting composite is achieved, according to which the reinforced bimetallic casting composite can be manufactured in a less time consuming and less costly manner. A reduction in space for the machine is obtained, as well as a reduction in machine and production costs and an increase in process productivity.

Fig. 2A shows a schematic sketch representing a method and an apparatus 1 according to the invention, wherein the method performs the steps of placing a metal insert 2 in a mould 3 and holding the metal insert 2 in the mould 3. The metal insert 2 is placed inside the mould 3, in particular in a mould cavity 4 of the mould 3, wherein the metal insert 2 is held by two transverse actuators 5. These transverse actuators 5 thus act as locators for the metal insert 2. The two transverse actuators 5 are part of a fixed part 6 of the mould 3. The metal insert 2 is a flat sheet in the embodiment shown and is provided to the mould 3 in a preformed state.

In addition to the fixed part 6, the mould 3 also comprises a moving part 7, the moving part 7 being arranged opposite the fixed part 6 and being movable in the closing direction 8. The closing direction 8 is the direction: the moving part 7 is moved in this direction so that the closing operation of the method is performed, that is to say so as to close the mould 3, in particular the mould cavity 4, so that the metal-clad casting step can be performed.

The moving portion 7 of the mould 3 comprises a closing element 9, which closing element 9 is adapted to close the mould cavity 4 of the mould 3 by its movement in the closing direction 8, i.e. in the direction of the closing direction 8. The moving portion 7 of the mould 3 further comprises an ejection portion 10, which ejection portion 10 is adapted to remove the finished component from the mould 3 or, respectively, from the mould cavity 4.

The closing element 9 further comprises an actuator as a thermo-compression actuator 11. The hot-pressing actuator 11 is adapted to perform a hot-stamping operation on the metal insert 2, and the hot-pressing actuator 11 is part of the moving part 7 of the die 3 and of the closing element 9. Therefore, the thermo-compression actuator 11 can also move back and forth in the closing direction 8. The movement in the closing direction 8 can be effected independently of the movement of the closing element 9 or also in connection with the movement of the closing element 9. The movements of the closing element 9 and the thermo-compression actuator 11 are substantially both linear movements in the closing direction 8, independent of each other.

Furthermore, a metal path 12 is provided in the device 1, by means of which metal path 12 molten overcasting metal can be cast into the mould 3, in particular into the mould cavity 4. Thus, the metal path 12 is connected to the mould cavity 4 in a manner that allows liquid metal to flow through the metal path 12 up to the mould cavity 4.

Fig. 2B shows a schematic sketch corresponding to the reproduction in fig. 2A, wherein the method now performs the steps of the closing operation and the deforming operation. That is, the method or the corresponding device 1 is shown in a state according to two steps following the state as shown previously in fig. 2A.

In fig. 2B, the moving part 7 has been moved in the closing direction 8 towards the stationary part 6 of the mould 3 in order to perform the closing operation. At the same time, the deforming operation of the metal insert 2 has been performed such that the metal insert 2 is shown in fig. 2B in its as-cast state, which differs from its pre-formed state in that the metal insert 2 has been deformed from a flat thin sheet into a sheet comprising two side shoulder sections 13.

The deformation operation of the metal insert 2 has been performed by means of a hot-pressing actuator 11, which hot-pressing actuator 11 is moved into the closing direction 8 together with the closing element 9 or respectively with the moving part 7 of the mould 3. Thus, the closing force has been used to perform the deforming operation. The deforming operation corresponds to a hot stamping operation, since the metal insert 2 inside the die 3 is heated. Such heating can be achieved by preheating the metal insert 2 before placing the metal insert 2 inside the mould 3 or by the heat inside the mould 3, which is present for example due to the heated mould surface. The deformation operation is supported by two lateral actuators 5 or positioners.

According to the embodiment as shown in fig. 2B, the closing operation of the mould 3 and the deformation operation of the metal insert 2 have been performed simultaneously, in particular by the same step, i.e. by closing the mould 3 due to the linear movement of the closing element 9 and the hot press actuator 11. Alternatively, the two steps, i.e. the closing operation and the deforming operation, can also be performed in a sequential manner. That is, the mold 3 may be closed after the deforming operation has been performed or, alternatively, before the deforming operation is performed later.

Fig. 2C shows a schematic sketch of a reproduction article corresponding to fig. 2A and 2B in a state where the retracting movement of the actuator is performed according to the method. That is, the thermo-compression actuator 11 and the two lateral actuators 5 are retracted back or away from their previous positions as shown in fig. 2B. The hot-pressing actuator 11 is therefore moved back away from the stationary part 6 of the mold 3 in the closing direction 8 or in other words against the closing direction 8. The two lateral actuators 5 are moved laterally away from the two side shoulder sections 13 of the metal insert 2. Said retracting movement of the actuator is indicated in an exaggerated manner in fig. 2C by means of a dashed arrow.

Due to said retracting movement of the actuator, the mould cavity 4 is released again in a manner allowing the liquid metal to flow through the metal path up to the mould cavity 4. Prior to the retracting movement, the metal insert 2 contacts the actuators, in particular the hot-pressing actuator 11 and the two transverse actuators 5 (see fig. 2B), and therefore the molten stream of the overcasting metal cannot reach its destination, i.e. the metal insert. At the same time, the retraction movement of the hot-pressing actuator 11 does not result in the opening of the mould 3 or of the corresponding mould cavity 4. In other words, the closing operation of the mold 3 is not withdrawn. This is because the thermocompression actuator 11 can be moved against the closing direction 8 independently of the closing element 9, the closing element 9 still serving to keep the mold 3 and the mold cavity 4 closed.

However, it is also possible to open the mold 3 or the corresponding mold cavity 4 again by said retracting operation, so that a new closing operation of the mold 3 is required. This condition is referred to as a retraction and closing operation.

Fig. 2D shows a schematic sketch of the reproduction in fig. 2A, 2B and 2C corresponding to the method in a state in which a metal overcasting step is carried out. Despite the hot-pressing actuator 11 being in the retracted state, the mold cavity 4 of the mold 3 is still closed by the closing element 9. Molten overcasting metal 14 has been cast into the mould cavity 4 after passing through the metal path 12. The molten overcasting metal 14 surrounds the metal insert 2 at the entire inner surface of the metal insert 2. Furthermore, the outer surfaces of the two side shoulder sections 13 are also in contact with the molten overcasting metal 14 due to the previous retraction movement of the transverse actuator 5.

Fig. 2E shows a schematic sketch of a reproduced article corresponding to fig. 2A, 2B, 2C, and 2D in a state where the mold opening and part extraction steps are performed according to the method. After the overcasting metal 14 solidifies, the metal insert 2 may be removed with the overcasting metal 14 bonded to the metal insert 2. Thus, the reinforced bimetallic casting composite is removed from the mold 3 or, respectively, from the mold cavity 4. The removal of the reinforced bimetallic casting composite is combined with the opening of the mold 3. In particular, the moving portion 7 of the mold 3 moves away from the fixed portion 6 of the mold 3 and, at the same time, the ejection portion 10 of the mold 3 withdraws the enhanced bimetallic casting composite, i.e., the metal insert 2, from the mold cavity 4 along with the overcast metal 14. The laterally retracted position of the two lateral actuators 5 allows the metal insert 2 to move together with the overcasting metal 14, since the two lateral actuators 5 or locators no longer hold the metal insert 2 inside the mould cavity 4.

After removal of the reinforced bimetallic casting composite, a final finishing operation, such as a machining operation, of the reinforced bimetallic casting composite may also be performed. Further, the inner surface of the mold cavity 4 or the mold 3 may be treated with a mold release agent for a subsequent production process.

Fig. 3A and 3B both show a schematic sketch representing alternative steps of the method and device according to the invention corresponding to the reproduction in fig. 2A to 2E with a retraction and closing operation for the closing element 9. In the state shown in fig. 3A and 3B, the deformation process of the metal insert 2 has been already performed. The metal insert 2 thus comprises its two side shoulder sections 13. However, the metal overcasting step has not been performed and the metal insert 2 is arranged in the mould cavity 4 without any overcast metal present.

In both fig. 3A and 3B, a retraction and closing operation is performed, wherein by means of the retraction and closing operation the closing element 9 is at least partially turned over and a further closing operation of the mould 3 is performed. No further closing operation of the mold 3 has been performed in the embodiment shown in fig. 3A and 3B. However, a type of retraction movement of the closing element 9 is shown.

In fig. 3A, the retracting movement of the closing element 9 comprises a sliding movement of the closing element 9 to a side substantially perpendicular to the closing direction 8, as indicated by arrow 15. In contrast, in fig. 3B, the retracting movement of the closing element 9 comprises a rotational movement of the closing element 9 about an axis substantially parallel to the closing direction 9, as indicated by arrow 16.

In both cases, after the retraction movement of the closing element 9, i.e. after the opening of the cavity 4 of the mould 3, a new closing operation of the mould 3 must be performed in order to close the cavity 4 again, so that it is ready for the subsequent metal overcasting step as described above in connection with the previous embodiments. Thus, the closing element 9 is not used for the final closing of the mold cavity 4, but another additional subsequent closing element is used for the final closing of the mold cavity 4, and thus the closing element 9 can be regarded as a moving deformation tool.

In the context of the present invention, the term "comprising" and its derivatives (such as "comprises", "comprising", "contains", etc.) should not be taken in an exclusive sense, i.e. these terms should not be interpreted as excluding the possibility that the contents of the description and definition may include other elements, steps, etc.

In the context of the present invention, the term "about" and its family of terms (such as "approximately" and the like) should be understood to mean very close to the values which accompany the above term. That is, deviations within reasonable limits of the exact value should be accepted, as those skilled in the art will appreciate that such deviations in the expressed values are unavoidable due to measurement inaccuracies and the like. The same applies to the terms "about" and "left and right" and "approximately".

It is obvious that the invention is not limited to the specific embodiments described herein, but also comprises any variant (for example, as regards the choice of materials, dimensions, components, configurations, etc.) that can be considered by a person skilled in the art within the general scope of the invention defined in the claims.