Coating apparatus for coating components

Abstract

The invention relates to a coating apparatus (1) for coating components (2), in particular for nickel plating spark-plug housings. The coating apparatus comprises: a housing (3) with an outer anode (4), which is designed to receive the component (2), an inner anode (5), which can be inserted into a through-opening (21) of the component (2), and a voltage generating device (6), wherein the voltage generating device (6) is designed to generate a first voltage between the outer anode (4) and the component (2) and also a second voltage between the inner anode (5) and the component (2), and wherein the housing (3) has an inlet (31) and an outlet (32), for introducing (71) and discharging (72) a process medium into and out of the housing (3).

Description

State of the art

[0001] The present invention relates to a coating device for coating components, in particular for nickel-plating spark plug housings. The invention further relates to a coating system.

[0002] The coating of components, such as spark plug housings, is known to occur via drum coating. In this process, the components are introduced into a drum as bulk material, and the components inside the drum then undergo all coating steps in bulk.

[0003] US 3 065 153 shows a coating plant. Disclosure of the invention

[0004] In contrast, the coating device according to the invention with the features of claim 1 offers the advantage of an improved device by means of which very high-quality coatings of components can be produced in a short time. This is achieved according to the invention by a coating device comprising a housing with an external anode, an internal anode, and a voltage generation device. The external anode is thus part of the housing and is configured to receive the component, which is preferably a spark plug housing, i.e., to encompass the component. The internal anode can be inserted into a through-opening of the component. Furthermore, the voltage generation device is configured to generate a first voltage between the external anode and the component, as well as a second voltage between the internal anode and the component. The housing also has an inlet and an outlet.The inlet allows a process medium to be introduced into the housing, and the outlet allows the process medium to be discharged from the housing.

[0005] The coating device is designed to accommodate exactly one component at a time, allowing both the outer and inner surfaces of the component to be completely and thoroughly coated, preferably nickel-plated, with high quality. The direct flow of the process medium around the component enables a very high coating rate, meaning a very rapid deposition of a layer onto the component.

[0006] According to the invention, the housing further comprises a cover with a clamping device. The clamping device is designed to clamp the component in order to hold it in a predefined position within the external anode. That is, the component is held in the housing solely by the clamping device.

[0007] According to the invention, the component is a spark plug housing with a ground electrode. The clamping device is designed to clamp the ground electrode. This provides a particularly simple way of mounting the spark plug housing within the external anode.

[0008] The dependent claims contain preferred further developments of the invention.

[0009] Preferably, the clamping device is designed such that it at least partially covers a surface of the ground electrode when clamped. In particular, the clamping device covers at least 80%, and more preferably at least 95%, of the surface of the ground electrode in this clamped state. This means that the clamping device surrounds the ground electrode of the spark plug housing in such a way that, on the one hand, a defined support of the spark plug housing within the outer anode is enabled, and on the other hand, a surface of the ground electrode is largely covered. This prevents the ground electrode from coming into contact with the process medium during the coating process and thus being excluded from the coating. This is particularly advantageous when only partial coating of the spark plug housing is intended.

[0010] For example, the process medium is a nickel electrolyte. Thus, the coating process is equivalent to nickel plating the component, meaning a nickel coating is created on the component.

[0011] Preferably, the inner anode is adjustable along a longitudinal axis of the housing to adapt the coating formation on the inside of the component. For example, this allows for different coating thicknesses to be achieved on the inside of the component.

[0012] Preferably, the coating device further comprises a flow control device for regulating the flow of the process medium through the housing. The flow control device is an orifice plate, which is preferably rotatable. For example, such a rotatable orifice plate can be provided as two discs with multiple through-holes that can be rotated relative to each other. By rotating the two discs relative to each other, the overlap of the through-holes changes, thereby adjusting the total free flow cross-section and thus the flow through the housing.

[0013] For example, the flow control device can be used to regulate a first flow between the inner anode and / or a second flow between the outer anode and the component. It is particularly advantageous if the first and second flow rates can be controlled independently of each other by the flow control device, in order to flexibly adapt the flow of the process medium through the housing to the desired properties of the coating both inside and outside the component.

[0014] Furthermore, the invention leads to a coating system comprising at least one, preferably at least 20, and particularly preferably 48, coating devices. The coating system further comprises at least one, preferably exactly two, voltage generation devices per coating device. Thus, a particularly efficient and rapid coating of the components can be achieved in a single system. Brief description of the drawing

[0015] The invention is described below with reference to an exemplary embodiment in conjunction with the figure. In the figure, functionally identical components are each identified by the same reference numerals. The figure shows: Figure 1 shows a simplified schematic sectional view of a coating device according to a preferred embodiment of the invention. Preferred embodiment of the invention

[0016] The Figure 1 Figure 1 shows a simplified schematic sectional view of a coating device 1 according to a preferred embodiment of the invention. The figure shows an operating state of the coating device 1 while a component 2 arranged in the coating device 1 is being coated. The component 2 is a spark plug housing with a straight ground electrode 22.

[0017] The coating device 1 comprises a housing 3 with an external anode 4. The housing 3 extends substantially along a longitudinal axis 10. The component 2 is arranged inside the external anode 4. The external anode 4 has an inner contour which is adapted to an outer contour of the component 2.

[0018] An internal anode 5 of the coating device 1 is arranged within a through-opening 21 of component 2. The internal anode 5 is fastened to a base 35 of the housing 3 by means of a screw 51. The internal anode 5 can be adjusted along the longitudinal axis 10 by means of the screw 51.

[0019] Furthermore, the housing 3 includes a cover 8 with a clamping device 81. The ground electrode 22 of component 2 is clamped in the clamping device 81 in order to hold component 2 in a defined position within the external anode 4. The ground electrode 22 is thereby in the Figure 1 shown in an as yet unbent state, and thus also extends in the direction of the longitudinal axis 10. As in the Figure 1It can also be seen that by clamping the ground electrode 22 in the clamping device 81, more than 90% of the surface of the ground electrode 22 is covered by the clamping device 81 in order to prevent coating of the ground electrode 22 on exactly this covered surface.

[0020] Furthermore, the housing 3 has an inlet 31 at its base 35, through which a process medium can be introduced into the housing 3 in the direction of 71. Additionally, a drain 32 is provided in the housing 3, through which the process medium, after flowing over or through the component 2, can be discharged from the housing 3 in the direction of 72.

[0021] The coating device 1 further comprises a flow control device 9, which is arranged at the transition between the base 35 and the outer anode 4. The flow control device 9 is designed as an orifice plate with several holes 91 in order to regulate the flow, in particular the volumetric flow rate, of the process medium through the housing 3 by rotation.

[0022] The process medium is a nickel electrolyte, which can then be used to create a nickel coating on component 2.

[0023] To produce such a nickel coating on component 2, the coating device 1 further comprises a voltage generation device 6. A first voltage can be generated between the outer anode 4 and component 2 by means of the voltage generation device 6. In addition, a second voltage can also be generated between the inner anode 5 and component 2. Thus, by applying the first and second voltages while the process medium flows through the housing 3, the nickel coating can be produced on both the inside and the outside of component 2.

Claims

1. Coating apparatus for coating components (2), in particular for nickel plating spark plug housings, comprising: - a housing (3) with an outer anode (4) which is configured to accommodate the component (2), - an inner anode (5) which can be inserted into a through-opening (21) in the component (2), and - a voltage generating device (6), - wherein the voltage generating device (6) is configured to generate a first voltage between the outer anode (4) and the component (2) and a second voltage between the inner anode (5) and the component (2), and - wherein the housing (3) has an inlet (31) for introducing (71) a process medium into the housing (3) and an outlet (32) for discharging (72) the process medium from the housing (3), wherein the housing (3) further comprises a cover (8) with a clamping apparatus (81), wherein the clamping apparatus (81) is configured to clamp the component (2) in order to hold the component (2) in a predefined position within the outer anode (4), and wherein the component (2) is a spark plug housing with an earth electrode (22), and wherein the clamping apparatus (81) is configured to clamp the earth electrode (22).

2. Coating apparatus according to Claim 1, wherein the clamping apparatus (81) at least partially covers a surface of the earth electrode (22) in the clamped state, and wherein the clamping apparatus (81) covers in particular at least 80%, particularly preferably at least 95%, of the surface of the earth electrode (22) in the clamped state.

3. Coating apparatus according to either of the preceding claims, wherein the inner anode (5) is adjustable along a longitudinal axis (10) of the housing (3).

4. Coating apparatus according to any of the preceding claims, further comprising a flow control device (9) for controlling the flow of the process medium through the housing (3), wherein the flow control device (9) is an, in particular rotatable, perforated plate.

5. Coating installation comprising: - at least one, in particular at least 20, preferably 48, coating apparatus(es) (1) according to any of the preceding claims, and - at least one, in particular two, voltage generating device(s) (6) per coating apparatus (1).

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