CN112207249B

CN112207249B - Casting device and method for producing a component from a melt

Info

Publication number: CN112207249B
Application number: CN202010668406.2A
Authority: CN
Inventors: D·贝费龙格
Original assignee: Phoenix Contact GmbH and Co KG
Current assignee: Phoenix Contact GmbH and Co KG
Priority date: 2019-07-12
Filing date: 2020-07-13
Publication date: 2022-05-10
Anticipated expiration: 2040-07-13
Also published as: LU101305B1; CN112207249A; PL3763459T3; EP3763459A1; EP3763459B1; HUE060494T2

Abstract

The invention relates to a casting device and a method for producing components from a melt, in particular a casting device for producing components from a melt is described and shown with: pouring a piston; a pouring channel; a shaped hollow space, wherein the melt can be supplied to the shaped hollow space via a pouring channel, wherein a pouring piston can be moved axially in the pouring channel, wherein the pouring piston can be moved from a first position into a second position, wherein the melt is brought into the shaped hollow space when the pouring piston is brought from the first position into the second position, and wherein a volume of the pouring piston that is extruded within the pouring channel when brought from the first position into the second position corresponds to a volume of the shaped hollow space. A casting device which can be operated more efficiently with a minimum of time expenditure is characterized in that the casting piston can be moved from the second position into the third position.

Description

Casting device and method for producing a component from a melt

Technical Field

The invention relates to a casting system for producing components from a melt, comprising: pouring a piston; a pouring channel; a shaped hollow space, wherein a melt can be supplied to the shaped hollow space via a pouring channel, wherein a pouring piston can be moved axially in the pouring channel, wherein the pouring piston can be moved from a first position into a second position, wherein the melt is brought into the shaped hollow space when the pouring piston is brought from the first position into the second position, and wherein a volume of the pouring piston which is extruded within the pouring channel when brought from the first position into the second position corresponds to a volume of the shaped hollow space which is completely filled with the melt in the second position of the pouring piston.

The invention further relates to a method for producing a component from a melt using a casting device having a casting channel, a casting piston and a shaped hollow space for the shaped component, wherein the casting piston is moved axially in the casting channel from a first position into a second position, wherein a volume corresponding to the volume of the shaped hollow space is extruded by the movement of the casting piston, wherein the melt is conveyed from the casting channel into the shaped hollow space by extruding the volume.

Background

In a casting installation, for example in a metal casting installation, liquid metal in the form of a melt is introduced into the shaped hollow space. The metal can be solidified in the shaped hollow space and adopts the preset shape of the shaped hollow space as a finished member. In the case of the injection molding method, a liquid melt is introduced into a mold cavity of an injection mold under high pressure and at a high mold filling speed by means of a casting piston.

DE 102012010923 a1 shows, for example, a conveying device for molten metal in an injection press train. The conveying device has a supply container for the metal melt and a conveying channel. The metal melt is supplied to the forming hollow space through the transfer channel. The transfer channel contains a piston that is axially movable in the transfer channel. Furthermore, an inflow channel is formed in the conveying channel, which inflow channel is connected to a reservoir, from which liquid melt can be conducted into the conveying channel.

DE 102014018795 a1 likewise discloses a conveying device for molten metal in an injection pressure unit. The metal melt is extruded by means of a piston via a conveying channel into the shaped hollow space. The piston is disposed in the cylindrical bore. A replaceable fitting is arranged in the cylindrical bore. Thus, fittings exposed to high thermal loads over time can be simply replaced.

Due to this load and the relatively high pressure, process fluctuations during casting are not uncommon. It is precisely in the hot-chamber die casting method that process fluctuations occur, which are usually compensated by targeted overflow in the region of the shaped hollow space. But this results in: a corresponding waste piece (abdalallanbtail) is produced and the article needs to be reprocessed.

Disclosure of Invention

The object of the present invention is therefore to provide a casting system and a method for producing components from a melt, which casting system can be operated more efficiently with a minimum of time expenditure.

This object is achieved in the above-mentioned casting installation by: the casting piston can be moved from the second position into a third position, the volume of the casting piston which is extruded out of the casting channel when being brought from the first position into the second position and from the second position into the third position being greater than the volume of the shaped hollow space, and an ejection device is provided in the region of the casting channel, through which ejection device the melt can be ejected from the shaped hollow space when the casting piston is in the third position.

When the casting device is filled with melt, the melt is then conveyed into the shaped hollow space by bringing the casting piston from the first position into the second position. The volume extruded by the casting piston corresponds exactly to the filling amount of the shaped hollow space. If the casting piston continues to move, that is to say from the second position into the third position, it moves past a point of travel (Wegpunkt) at which it extrudes a volume in the casting channel corresponding to the volume of the shaped hollow space. The pressure of the system is thereby increased, since the casting piston moves relative to the incompressible medium. In order to equalize this pressure, according to the invention a discharge device is provided in the region of the pouring channel. Due to the continuity, the melt is thus conveyed out of the discharge device, whereby the pressure can also be kept at a lower level.

The part of the melt discharged from the discharge device corresponds to the volume of the casting piston that is extruded in the casting channel from the second position into the third position. The advantage of the invention is therefore that no reworking of the finished component is necessary, since the desired geometry of the component can be realized in only one method step. Thus, scrap-free manufacture can be achieved. Furthermore, the pressure of the system can be kept low, since the built-up pressure of the casting piston that extrudes the melt into the molding hollow space can be reduced by the discharge device (abbauen, sometimes referred to as cut-back). The discharge device presents the weakest sealing area of the casting apparatus.

The pouring channel can open directly into the shaped hollow space. However, it can also be provided that the pouring channel and the shaped hollow space are connected to one another via one or more supply lines. The melt is then conveyed via the pouring channel into the supply line and from there into the molding hollow space.

In a first embodiment of the casting device according to the invention, it is provided that the discharge device is formed by a leakage gap between the casting piston and the casting channel. In this way no additional holes or the like are required in the casting piston. The normally undesired leakage gap between the casting piston and the casting channel can be specifically designed in such a way that a specific backflow of the melt past the casting piston and back into the casting channel is possible.

Alternatively or additionally, it can be provided that the discharge device is formed by an overpressure valve in the pouring channel. An overpressure valve can be arranged between the casting piston and the shaped hollow space. In this way, when no or only a small leakage gap is provided between the casting piston and the casting channel, the melt flows through the flow channel of the overpressure valve and not through the casting piston.

In order to convey the melt in the liquid state into the forming hollow space, it is provided in a further embodiment of the casting device according to the invention that the casting channel is heatable. In this way it is ensured that the melt does not already start to solidify when it is fed through the pouring channel into the shaped hollow space.

In order to achieve a great flexibility of the component to be cast, in a further embodiment of the casting device according to the invention, an insert part which can be cast in a surrounding manner is provided in the shaped hollow space. The insert part is just for the benefit of the light metal cast component, which is integrated into the component by surrounding casting. In this way, local material improvements can be achieved, for example better wear resistance, higher mechanical strength and heat resistance.

The casting installation according to the invention can also be operated automatically. For this purpose, in a further embodiment, a drive, preferably an electric drive, is provided for displacing the casting piston. Due to the low viscosity of the melt, the process can be adjusted in each cycle in such a way that more volume is dosed than is required for completely filling the molding cavity. After the complete Form filling (Formlung), the further volume is then reduced again with a small relative pressure via the discharge device. The drive can also be operated hydraulically, mechanically or by means of other conventional methods. In a corresponding system design, the system pressure can be significantly limited as described by the targeted use of the evacuation device and by the design of the drive device, for example, in order to protect the insert parts and the system parts from high loads.

In order to further simplify the process control of the casting installation, a heatable storage container is provided in a further embodiment of the invention, which is connected to the casting channel, so that the melt can be conveyed from the storage container into the casting channel. In the reserve container, the material is completely melted. The melt can flow into the pouring channel directly or via a corresponding filling line. For this purpose, holes can be provided in the pouring channel.

It is also conceivable to provide a non-return valve at the transition from the reservoir to the pouring channel. The non-return valve remains in the blocking position when the casting piston is moved from the first position into the second position or into the third position. At this time, the molding hollow space is filled with the melt. When the casting piston is brought from the third position or the second position into the first position, the shut-off valve is opened, so that the melt can pass from the reservoir into the casting channel. A further supply line can open into the storage tank. For example, it is conceivable for the outlet device to be formed by an overpressure valve, with an outflow line returning into the reservoir being provided. The outflow line can likewise be heated, so that the liquefied melt can be pumped into the storage tank without problems and the next casting process can be continued without waiting time.

According to a second teaching, the invention relates to a method for operating a casting system for producing components from a melt, in which method the previously identified object is solved. The method according to the invention is characterized firstly and essentially in that the casting piston is moved from the second position into the third position, the volume which is extruded by the casting piston in the casting channel from the first position into the second position and from the second position into the third position is greater than the volume of the shaped hollow space, and the volume of the extruded melt is conveyed out of the shaped hollow space by a discharge device which is arranged in the region of the casting channel when being brought from the second position into the third position.

The method can be carried out with the aid of the aforementioned casting device. The statements made with respect to the casting installation according to the invention apply correspondingly to the method according to the invention. All statements made with respect to the casting installation apply equally to the method according to the invention and vice versa.

In a preferred variant of the method according to the invention, the excess melt is conducted back into the pouring channel via the tapping device via a pouring piston. The following advantages are obtained by the method steps: no melt runs off in the system, but the excess melt is directly conducted back into the pouring channel and can be used further for the next pouring process. By flowing the melt through the casting piston into the casting channel, the advantage of a very simple handling is obtained.

In another embodiment of the method according to the invention, the casting channel is heated. The heating of the pouring channel can be carried out before the actual pouring process, can be carried out during the pouring process and can also be maintained after the pouring process. The heating can also be effected before and during the casting process or can be effected before and during and after the casting process or can be effected during and after the casting process. By heating, the following effects are achieved: the melt does not solidify in the pouring channel, so that no residues are deposited at the walls of the pouring channel.

In a further variant of the method according to the invention, the insert part, which can be cast in a surrounding manner, is introduced into the shaped hollow space. The insert part is then encapsulated during the casting process.

Drawings

In detail, there are a large number of possible solutions to design and improve the casting device according to the invention and the method according to the invention. In the drawings:

figure 1a shows a schematic view of an embodiment of a casting device for producing components from a melt with a casting piston,

figure 1b shows the embodiment according to figure 1a with the melt filled in,

figure 1c shows the casting device according to figure 1b with the casting piston in the third position,

figure 2 shows a schematic view of a casting device with an overpressure valve,

fig. 3 shows a schematic view of a casting device with a non-return valve.

Detailed Description

Fig. 1a to 1c show a casting device 1 with a casting piston 2, which is arranged in a casting channel 3. The component is cast in the shaped hollow space 4. The casting installation additionally has an outlet device 5, from which the melt 6 can be discharged. Furthermore, a drive 7 for moving the casting piston 2 is provided. The melt 6 can be transported out of the storage container 8.

The casting piston 2 is arranged axially displaceable in the casting channel 3. The casting piston 2 can be moved by the electric drive 7 from the first position into the second position in the direction of the hollow space 4 and further into the third position in the direction of the hollow space 4. The molding hollow space 4 is formed in a mold 9, which is connected to the pouring channel 3 via an inflow channel 10. The mold 9 is exchangeable, so that various geometries for the respectively cast component are possible.

Fig. 1b shows the casting device 1 with the casting piston 2 in the second position. When the pouring piston 2 is moved from the first position into the second position within the pouring channel, a specific volume is squeezed out by the pouring piston 2. The volume which the casting piston 2 extrudes when being brought from the first position into the second position corresponds exactly to the volume of the shaped hollow space 4, so that the shaped hollow space 4 is completely filled with the melt 6. In different molds 9 with different shaped hollow spaces 4, the stroke to be covered by the casting piston 2 from the first position into the second position can be set by the operator, so that the volume of the extrusion of the casting piston 2 always corresponds to the volume of the shaped hollow space 4.

Fig. 1c shows the casting piston 2 in a third position. The volume of the pouring piston 2 extruded between the first position and the third position is greater than the volume of the shaped hollow space 4. When the pouring piston 2 is brought from the second position into the third position, the pressure in the system rises. The pressure is reduced by the discharge means 5. The discharge device is constructed in this embodiment by means of a leakage gap between the casting piston 2 and the casting channel 3. The leakage gap can be designed such that a specific pressure increase is achieved with a corresponding drive output. It is also conceivable that the casting pistons 2 are exchangeable and that the leakage gaps of different casting pistons 2 are adapted to different materials, so that other parameters of the process are adapted or remain unchanged. The discharge means 5 present a minimum tightness of the system. The liquid incompressible melt 6 is thus pressed through the outlet device with the pressure increased. The melt 6 can thus solidify under pressure in the shaped hollow space 4.

When the casting piston 2 is moved from the third position back into the second position or into the first position, a further free volume is created between the shaped hollow space 4 and the casting channel 3. The melt 6 undergoes a melt return in the direction of the pouring channel 3. In the first position of the casting piston 2, the additional free volume is present between the casting piston 2 and the shaped hollow space 4, which can be used for targeted acceleration of the electric drive 7. The filling of the molding hollow space 4 must be completed before the injected/injected material solidifies in order to ensure a process-reliable filling with a feasible small casting pressure.

The reservoir 8 is likewise heated. The storage container can be, for example, a heatable furnace in which the material to be poured is completely melted. The storage container 8 is connected to the pouring channel 3 by means of a bore 11. The bore 11 is arranged in the pouring channel 3 in such a way that the shaped hollow space 4 and the pouring piston 2 are located between the bore 11 when the pouring piston 2 is in the first position. In the second position of the casting piston 2 or in the third position of the casting piston 2, the bore 11 is covered by the casting piston 2, so that no melt 6 can be conveyed from the reservoir 8 into the casting channel 3.

Fig. 3 shows a casting device 1 similar to the exemplary embodiment shown in fig. 1a to 1 c. The casting piston 2 is driven by means of a drive 7, which is movable in translation in the casting channel 3. The pouring channel 3 can be heated, so that it is possible to completely melt different materials, mainly metal alloys. The pouring channel 3 is connected to a mould 9 having a shaped hollow space 4.

In contrast to the embodiment according to fig. 1a to 1c, a discharge device 5 in the form of an overpressure valve is arranged between the shaped hollow space 4 and the pouring channel 3. The tapping device 5 allows the liquid melt 6 to flow back into the reservoir 8 via the tapping channel 12. The outflow channel 12 is additionally heated, so that the melt 6 continues to remain liquefied and the next casting process can begin.

Fig. 3 shows an embodiment according to fig. 2. In contrast to fig. 2, when the casting piston 2 is in the second position or in the third position, the bore 11 is not covered by the casting piston 2. The bore 11 is equipped with a non-return valve 13. When the casting piston 2 moves from the first position into the second position or into the third position, the non-return valve 13 remains in the blocking position. At this time, the molding hollow space 4 is filled with the melt 6. When the casting piston 2 is moved from the third or second position into the first position, the non-return valve 13 opens, so that the melt 6 can pass from the reservoir 8 into the casting channel 3.

List of reference numerals

1 casting equipment

2 casting piston

3 pouring channel

4 shaped hollow space

5 discharge device

6 melt

7 drive device

8 storage container

9 mould

10 inflow channel

11 holes

12 outflow channel

13 check valve

Claims

1. Casting system (1) for producing components from a melt, comprising: casting the piston (2); a pouring channel (3); a molding hollow space (4), wherein the melt can be supplied to the molding hollow space (4) via the pouring channel (3), wherein the pouring piston (2) can be moved axially in the pouring channel (3), wherein the pouring piston (2) can be moved from a first position into a second position, wherein the melt is brought into the molding hollow space (4) when the pouring piston (2) is brought from the first position into the second position, and wherein a volume of the pouring piston (2) that is extruded within the pouring channel (3) when brought from the first position into the second position corresponds to a volume of the molding hollow space (4),

wherein,

the casting piston (2) can be moved from the second position into a third position, wherein the volume of the casting piston (2) that is extruded within the casting channel (3) when being brought from the first position into the second position and from the second position into the third position is greater than the volume of the shaped hollow space (4), and wherein an evacuation device (5) is provided in the region of the casting channel (3), through which evacuation device melt can be evacuated from the shaped hollow space (4) when the casting piston is in the third position, characterized in that the evacuation device (5) is formed by a leakage gap between the casting piston (2) and the casting channel (3).

2. Pouring device (1) according to claim 1, characterized in that the evacuation means (5) are formed by an overpressure valve in the pouring channel.

3. Pouring device (1) according to claim 1 or 2, characterized in that the pouring channel (3) is heatable.

4. Casting device (1) according to claim 1 or 2, characterized in that an insert part which can be enclosed for casting is provided in the shaped hollow space (4).

5. Pouring device (1) according to claim 1 or 2, characterized in that a drive means (7) is provided for moving the pouring piston (2).

6. Pouring device (1) according to claim 1 or 2, characterized in that the pouring channel (3) is connected with the shaped hollow space (4) in such a way that a free volume is created between the pouring channel (3) and the shaped hollow space (4) when the pouring piston (2) is brought from the second or third position into the first position.

7. Pouring device (1) according to claim 1 or 2, characterized in that a heatable reserve container (8) is provided, which is connected to the pouring channel (3) so that the melt can be transported from the reserve container (8) into the pouring channel (3).

8. Casting device (1) according to claim 5, characterized in that the drive means (7) is an electric drive means.

9. Method for operating a casting installation for producing a component from a melt, wherein the casting installation (1) has a casting piston (2), a casting channel (3) and a shaped hollow space (4) for shaping the component, wherein the casting piston (2) is moved axially in the casting channel (3) from a first position into a second position, wherein a volume corresponding to the volume of the shaped hollow space (4) is extruded by the movement of the casting piston (2), wherein the melt is conveyed from the casting channel (3) into the shaped hollow space (4) by the extrusion of the volume,

it is characterized in that the preparation method is characterized in that,

moving the pouring piston (2) from the second position into a third position, the volume extruded by the pouring piston (2) within the pouring channel (3) when brought from the first position into the second position and from the second position into the third position being greater than the volume of the shaped hollow space (4), the volume of the extruded melt when brought from the second position into the third position being conveyed out of the shaped hollow space (4) by a discharge device (5) arranged in the region of the pouring channel (3), and

excess melt is directed back into the pouring channel via the tapping device via the pouring piston.

10. Method according to claim 9, characterized in that the pouring channel is heated before, during and/or after the pouring process.

11. Method according to claim 9 or 10, characterized in that an insert part that can be cast in a surrounding manner is brought into the shaped hollow space.