Methods for repairing casting tools

Abstract

Method for repairing casting tools (10), wherein a channel wall (1) of a cooling channel (2) of a cooling device (3) of the casting tool (10) is sealed by galvanic coating.

Description

[0001] The present invention relates to a method for repairing casting tools and an arrangement for repairing casting tools.

[0002] Various methods are known for repairing casting tools, particularly tools for die-casting machines. This allows cracks in cooling channels, which can occur due to thermal cycling of the casting tool, to be repaired. Such cracks can lead to leaks in the cooling channels. It is known that cracks can be sealed by welding. Due to accessibility, welding is usually not carried out directly around the cooling channel, but rather from the side of the casting cavity. However, this often does not restore satisfactory tightness. It is also known that cooling channels with cracks are no longer used, for example, by being placed in air. However, this reduces the cooling effect in the casting tool.

[0003] It is therefore an object of the present invention to provide a method for repairing casting tools that can reliably and effectively restore or maintain optimal function of cooling channels. Furthermore, it is an object of the invention to provide an arrangement for repairing casting tools that allows for simple and cost-effective repair of cooling channels.

[0004] The object is achieved by a method according to claim 1 and by an arrangement according to claim 14.

[0005] The method according to the invention for repairing casting tools is characterized in that a channel wall of a cooling channel of a cooling device of the casting tool is sealed by galvanic coating.

[0006] In other words, the casting tool is repaired by electroplating the cooling channel wall. Specifically, the entire cooling channel wall is electroplated.

[0007] In particular, the method involves sealing a channel wall in which a crack or, for example, an alternative defect is located. Alternatively, the method can preferably be used to seal any channel wall of any cooling channel.

[0008] A cooling channel is considered to be, in particular, a cavity, for example a tubular cavity, in the interior of the casting tool, through which a cooling fluid can be passed in particular in order to dissipate heat from the casting tool by means of the cooling fluid.

[0009] The method is preferably intended for repairing casting tools designed for die casting, in particular for aluminum die casting. Such casting tools preferably have a permanent mold, which can be made of steel, for example.

[0010] The process offers the advantage that defects in cooling channels can be repaired particularly reliably and precisely. Because the channel wall is sealed directly through electroplating, leaks can be reduced or avoided particularly reliably and efficiently. In particular, leaks can be sealed precisely where they occur. This makes it possible to significantly extend the service life of casting tools in a simple, reliable and cost-effective manner. In addition, by sealing the channel walls of the cooling channels, it can be ensured that the cooling system of the casting tool functions optimally at all times. This means that components with particularly high material qualities can be reliably manufactured using the casting tool. By ensuring reliable cooling, damage to the tool can also be reduced or avoided.

[0011] Preferably, a metal layer is created on the channel wall by electroplating. In particular, the electroplating is carried out in such a way that the entire surface of the channel wall is completely covered with the metal layer. This allows the coating to be carried out particularly easily, efficiently, and reliably, especially when the casting tool is made of metal.

[0012] Preferably, the metal layer is made of a tough and / or temperature-resistant material. This provides a particularly reliable and durable seal.

[0013] The metal layer is particularly preferably made of nickel or a nickel alloy. This allows for particularly simple, efficient, and cost-effective electroplating. Furthermore, a durable coating can be provided, enabling a particularly long service life for the casting tool.

[0014] For electroplating, a plating liquid is preferably conveyed through the cooling channel, preferably by means of a pump. The plating liquid preferably comprises a transport medium, in particular an electrolyte, and a coating material, preferably an anode material, which is applied to the channel wall. This allows the entire channel wall of the cooling channel to be coated evenly in a simple and reliable manner. Furthermore, the method can be integrated particularly easily into the normal operation of the casting tool. This means, for example, that the tool can be repaired using the method without requiring complex modifications to a casting system in which the casting tool is used.

[0015] Particularly preferably, the electroplating liquid is provided by means of an electrolyte and an anode, which is preferably immersed in the electrolyte. The electrolyte and anode are preferably arranged within a plating tank. This allows for simple repair of the tool.

[0016] Further preferably, for electroplating, an electric current is applied between the anode, preferably immersed in the electrolyte, and the casting tool. This means that the electric current is applied directly to the casting tool itself. This allows the process to be carried out in a particularly simple and efficient manner.

[0017] Preferably, the electroplating liquid is conveyed through the cooling channel by means of a flow pump. A flow pump is considered, in particular, a pump designed to continuously convey a liquid. For example, the flow pump is designed as a propeller pump. This allows a continuous flow of electroplating liquid through the cooling channel in a simple and reliable manner. Furthermore, the design as a flow pump allows an electrical current to flow uninterruptedly in the electroplating liquid.

[0018] Preferably, the cooling channel is connected to electrically non-conductive hoses to conduct the electroplating fluid. This allows for particularly simple and precise electroplating.

[0019] Further preferably, the electroplating is carried out for a predetermined period of time, which in particular amounts to several days or weeks. This reliably ensures that a coating with a sufficient layer thickness is provided to enable reliable sealing of the channel walls of the channel.

[0020] Preferably, the channel wall is pickled and / or washed before electroplating. In particular, this renders the channel wall metallically bright. This allows a coating to be produced easily and reliably, and with high material quality. Preferably, the pickling and / or washing can be performed by flushing the cooling channel with an appropriate pickling agent and / or washing agent.

[0021] Further preferably, for electroplating, a sponge impregnated with an electrolyte and containing an anode is inserted into the cooling channel and moved along the cooling channel. Preferably, the sponge is moved alternately several times along both directions of the cooling channel. Preferably, the anode is arranged inside the sponge and / or the sponge is formed at least partially from an anode material. For example, such a process can also be referred to as coating by pin electroplating. This allows the coating of the channel wall to be created in an alternative manner.

[0022] Preferably, the sponge is moved along the cooling channel using compressed air. This allows the coating to be carried out using a particularly simple technique.

[0023] Preferably, the method further comprises the step of welding a crack in the casting tool to a wall of the casting tool facing a casting cavity of the casting tool. This means that a crack in the casting tool is additionally welded to a wall of the tool facing the casting cavity. This additional measure can further improve the seal.

[0024] Furthermore, the invention leads to an arrangement for repairing casting tools. The arrangement comprises means for carrying out the method described above. Preferably, the arrangement comprises a plating tank, an electrolyte, an anode, a flow pump, electrically non-conductive hoses, and a power supply device, which are particularly configured for carrying out the described method.

[0025] The invention is explained in more detail below using exemplary embodiments. These show: Fig. 1 a highly simplified schematic view of a method for repairing casting tools according to a first embodiment of the invention, Fig. 2 a detailed sectional view of the casting tool repaired by the method according to the invention, Fig. 3 a highly simplified schematic view of a method for repairing casting tools according to a second embodiment of the invention, and Fig. 4 a highly simplified schematic view of a method for repairing casting tools according to a third embodiment of the invention.

[0026] In the following, preferred embodiments of methods for repairing tools 10 are explained. Fig. 1 to 4. Identical or functionally equivalent components are always provided with the same reference numerals.

[0027] Fig. 1 shows an arrangement 30 for repairing casting tools 10, with which a method according to a first embodiment of the invention is carried out.

[0028] The casting tool 10 is an aluminum die-casting tool, which is designed as a permanent mold made of metal, in particular steel. The casting tool 10 is in the Fig. 1 is shown in a highly simplified schematic and only partially.

[0029] A wall 12 of the casting tool 10 defines a cavity 11 into which, when used in die casting, the liquid aluminum material is filled under pressure in order to cast components.

[0030] In Fig. 2 shows a detailed sectional view of the casting tool 10 repaired by means of the method according to the invention.

[0031] The casting tool 10 comprises a cooling device 3, which has a cooling channel 2, which runs in a meandering manner through the solid casting tool 10 in the immediate vicinity of the wall 12.

[0032] The cooling channel 2 can be flowed through by a cooling medium, which can be conveyed through the cooling channel 2 via an external coolant supply device (not shown).

[0033] During operation of the casting tool 10, cracks 20 may occur, particularly due to changing temperature stresses. For example, such cracks 20 may form starting from the cooling channel 2. In particular, the cracks 20 may extend from the cooling channel 2 into the cavity 11, causing undesirable leakage of the coolant (see, for example, Fig. 2).

[0034] By means of the arrangement 30, the casting tool 10 is repaired by the method according to the invention in such a way as to seal the cracks 20. For this purpose, a galvanic coating of a channel wall 1 of the cooling channel 2 is carried out.

[0035] The galvanic coating is carried out by passing a galvanic liquid 5 through the cooling channel 2.

[0036] The electroplating liquid 5 is provided by means of an electroplating tank 6 containing an electrolyte 7 and an anode 8. The anode 8 is, in particular, a nickel anode, so that a metal layer 4 made of nickel can be created on the channel wall 1 by the electroplating process.

[0037] The electroplating tank 6 is connected to one end of the cooling channel 2 by means of electrically non-conductive hoses 13.

[0038] A flow pump 9 is integrated into one of the two hoses 13 and is designed to pump the electroplating liquid 5 through the cooling channel 2.

[0039] The assembly 30 also includes a power supply device 14, which is connected to the anode 8 and directly to the casting tool 10, respectively, and provides a direct current. The flow pump 9 enables a continuous fluid flow of electroplating liquid 5 between the electroplating tank 6 and the cooling channel 2, which also allows a continuous current flow between the anode 8 and the cooling channel 2 to continuously effect the electroplating of the channel wall 1 during operation of the assembly 30.

[0040] The casting tool 10 can also be connected to an earth 16.

[0041] In this process, a metal layer 4 is created on the channel wall 1 by electroplating, by means of which the cooling channel 2 is sealed against the crack 20. To achieve a sufficient layer thickness, the process can be carried out over a long period of time, for example, several days or weeks.

[0042] The method thus makes it possible to provide a completely resealed cooling channel 2 even after the occurrence of cracks 20. This allows the cooling device 3 of the casting tool 10 to be fully functional again after the repair, thereby ensuring a long service life of the casting tool 10 and, thanks to consistently optimal cooling, enabling the production of components with high material quality using the casting tool 10.

[0043] Fig. Figure 3 shows a highly simplified schematic view of a method for repairing casting tools 10 according to a second embodiment of the invention. The second embodiment essentially corresponds to the first embodiment of the Fig. 1 and Fig. 2, with the difference that the crack 20 is additionally welded. In detail, the crack 20 is welded from the side of the casting cavity 11 to the wall 12 facing the casting cavity 11, thus being closed by means of a weld seam 17.

[0044] This allows for additional sealing by means of the weld seam 17. For example, the propagation of the crack 20 can be reduced.

[0045] Fig. Figure 4 shows a highly simplified schematic view of a method for repairing casting tools 10 according to a third embodiment of the invention. The third embodiment essentially corresponds to the second embodiment of the Fig. 3, with the difference of an alternative way of producing the metal layer 4. In the third embodiment of the Fig. 4, the electroplating is carried out using a sponge 15 impregnated with an electrolyte, inside which the anode 8 is arranged. The sponge 15 is inserted into the cooling channel 2 and moved back and forth along the cooling channel 2 by means of compressed air in order to distribute the electrolyte with the anode material on the channel wall 1.

[0046] For example, as shown in Fig. 4, a direct electrical voltage is generated between the casting tool 10 and the anode 8. In particular, a negative electrical potential 18 is generated at the casting tool 10 and a positive electrical potential 18 is generated at the anode 8.

[0047] For example, the power supply can be analogous to the first embodiment of the Fig. 1 via the electroplating liquid 5, or alternatively preferably directly via an electrical connection of the anode 8. List of reference symbols 1 canal wall 2 cooling channels 3 Cooling device 4 metal layer 5 Electroplating fluid 6 electroplating tanks 7 Electrolyte 8 Anode 9 Flow pump 10 Casting tools 11 Casting cavity 12 Wall 13 hoses 14 Power supply device 15 sponge 16 Grounding 17 Weld seam 18 electrical potentials 20 crack 30 Arrangement

Claims

[1] Method for repairing casting tools (10), wherein a channel wall (1) of a cooling channel (2) of a cooling device (3) of the casting tool (10) is sealed by galvanic coating. [2] Method according to claim 1, wherein the galvanic coating produces a metal layer (4) on the channel wall (1). [3] Method according to claim 2, wherein the metal layer (4) is formed from nickel or a nickel alloy. [4] Method according to one of the preceding claims, wherein a galvanic liquid (5) is passed through the cooling channel (2) for the galvanic coating. [5] Method according to claim 4, wherein the electroplating liquid (5) is provided by means of an electrolyte (7) and an anode (8), in particular wherein the electrolyte (7) and anode (8) are arranged within an electroplating tank (6). [6] Method according to claim 5, wherein an electric current is applied between the anode (8) and the casting tool (10) for the galvanic coating. [7] Method according to one of claims 4 to 6, wherein the electroplating liquid (5) is conveyed by means of a flow pump (9) in order to pass the electroplating liquid (5) through the cooling channel (2). [8] Method according to one of claims 4 to 7, wherein in order to pass the electroplating liquid (5) through the cooling channel (2), the cooling channel (2) is connected to electrically non-conductive hoses (13). [9] Method according to one of the preceding claims, wherein the electroplating is carried out over a period of several days or weeks. [10] Method according to one of the preceding claims, wherein the channel wall (1) is pickled and / or washed before the galvanic coating. [11] Method according to one of the preceding claims, wherein for the galvanic coating, a sponge (15) impregnated with an electrolyte with an anode (8) is inserted into the cooling channel (2) and moved along the cooling channel (2). [12] Method according to claim 11, wherein the movement of the sponge (15) is effected by means of compressed air. [13] Method according to one of the preceding claims, further comprising the step: Welding a crack (20) on a wall (12) of the casting tool (10) facing a casting cavity (11) of the casting tool (10). [14] Arrangement for repairing casting tools (10), which comprises means for carrying out the method according to one of the preceding claims, in particular comprising: a galvanic tank (6), an electrolyte (7), an anode (8), a flow pump (9), electrically non-conductive hoses (13), and a power supply device (14).

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