EP2524071A1

EP2524071A1 - Tool for galvanically coating sliding bearings

Info

Publication number: EP2524071A1
Application number: EP11700735A
Authority: EP
Inventors: Hans-Ulrich Huhn; Axel Rothe
Original assignee: Federal Mogul Wiesbaden GmbH
Current assignee: Federal Mogul Wiesbaden GmbH
Priority date: 2010-01-13
Filing date: 2011-01-12
Publication date: 2012-11-21
Anticipated expiration: 2031-01-12
Also published as: MX2012008125A; CN102812163B; JP2013517377A; KR101712353B1; WO2011086089A1; JP5635127B2; DE102010000853A1; CN102812163A; BR112012017230A2; KR20130004260A; US20130032475A1; US9017531B2; EP2524071B1

Abstract

The invention relates to a tool for galvanically coating sliding bearings comprising at least one cover (34), to which a thief (36) is attached.

Description

Tool for electroplating plain bearings

Technical area

The invention relates to a tool for galvanic

Coating of plain bearings.

The typical structure of a plain bearing from the material group of plain bearings to be plated consists of a

Steel backing with a leaded or lead free

Layer composite. The applied in the running surface of the sliding bearing galvanic sliding layer is a

multifunctional material and takes on different

Tasks. This coating takes place in a box-shaped tool, which is also referred to as recording. When coating it is also to be noted that those surfaces on which the bearing shells are divided (partial surface),

preferably not coated. Furthermore, for the

Bearing back, i. the cylindrical outer surface of the

Bearing shells, no coating desired. For this purpose, so-called Räubrrkkodes or elements are provided in the region of the bearing back, which are connected in a suitable manner such that the bearing back of a

Coating remains largely free. State of the art

So far, one or more "towers" or pillars of

Cups constructed in such a way that the

Axial directions of the individual bearing shells coincide. In this axial direction, the bearing shells are clamped by means of a spring pressure. However, this structure is

comparatively unstable, so that the bearing shell columns often collapse, strong on the faces

are coated and results in a significant proportion of committee. At the beginning and at the end of the respective column so-called dummy shells made of steel are used. The blind shell at the beginning of the bearing shell pillar to be coated covers the transition area between the air and the electrolyte. The lower dummy shell serves to stabilize the column and to limit the tolerance of the deposited layer within the bearing shell column. The above-mentioned robber cathode is fixed in the tool.

Presentation of the invention

The invention has for its object to provide a tool with the help of plain bearing shells can be galvanically coated efficiently.

The solution to this problem is achieved by the tool described in claim 1.

Consequently, the tool according to the invention has at least one cover on which a robber cathode is mounted. In other words, the robber cathode is integrated in the lid, which leads to the particular advantages that it can be removed during the process. This

differs from the previous fixed in the tool cathodes. The possibility of removing the raid cathode during the coating process offers the following

Advantage. The tread is usually after the "main" - Coating provided with a binary or ternary lead-free sliding layer. The steel back must then be provided with a so-called flash. This flash, for example, based on tin has the function of

Protected against corrosion and is primarily applied to the bearing back of steel to protect the reactive steel from oxidation with the air (rust). This

Corrosion protection is thus primarily to be applied to the bearing back. However, this area is not coated in the presence of the robber cathode. While, therefore, in the context of the main coating, the electricity before going to the

Coating bearing shells is passed over one

Resistance of, for example, 0.001 ohms to 0.02 ohms, in particular 0.003 ohms to 0.0095 ohms is passed to produce a potential difference between the burglar cathode and the bearing shells to prevent the coating to the back, this potential difference by

Removing the robber cathode is repealed, and the bearing backs can advantageously match the desired one

Corrosion protection are provided.

Preferred developments of the tool according to the invention are described in the further claims.

Preferably, the tool according to the invention further

at least one holder, which is characterized in that it has at least one strip which is suitable for mechanically fixing and / or electrically contacting a plurality of bearing shells. The mechanical fixation, optionally in cooperation with a portion, for example a wall of the tool, prevents the bearing cup column from collapsing. The holder presses namely with the at least one bar the bearing shell pillar, for example, against a wall of the tool, so that a much lower risk of collapse of the

Lagerschalensäule consists, the collapse of the

Bearing column eliminated and the coating of the Part surface is avoided. This reduces the

Scrap share clearly. In particular, it was found in initial tests that the scrap can be reduced to zero due to collapsed bearing shells. Furthermore, the undesired coating of the partial surfaces can be prevented by pressing against the tool wall.

By contacting a plurality of bearing shells at their respective back several, preferably all to be coated cups are contacted by the holder according to the invention. This reduces the resistance

within the bearing shell column, and the sliding surface of the bearing shell can be coated with a significantly reduced dispersion of the coating thickness. In particular, it was found that the dispersion within a

Lagerschalensäule with the holder according to the invention is only about 2 pm to 3 pm and the coating of the partial surface is avoided, while in the previous procedure, in which only the front sides of the bearing shell column were contacted, a scattering of 6 pm to 7 microns occurred and the

Partial surface was coated with up to 20 microns. As a result, the Committee was able to

Coating density can be significantly reduced. Of the

described holder can be referred to as Rückenkontaktierung due to its function. This constitutes an independent aspect of the present application which is independent of the preceding or following

described characteristics unfolds its advantages, however, can be combined with these.

In particular for the stability with regard to

mechanical fixation have several, especially an even number of substantially parallel bars as

proved advantageous. Together with the pressing against a wall of the tool, for example, by two parallel bars a statically determined fixation can be created. It is also the efficiency of the coating

several, in particular comparatively small bearing shells low, if two or more bearing shell pillars are constructed side by side, which means an even number largely parallel strips for a mechanically favorable fixation. It is understood that only two or three such

Bars can be present to a single

Contact bearing cup column electrically and mechanically fix. This can be provided, for example, with comparatively large bearing shells. It is further

conceivable in principle to provide such a holder for more than two bearing shell columns. A holder for two bearing shell columns has proven, for example, for bearing shells with a diameter of 28 mm to 70 mm, while for larger bearings a holder for a single

Bearing shells can be provided.

The specific requirements for the respective components can be particularly well done when the holder, as is preferred, even made of plastic, and the contact strips or rails are made of metal.

In this case, it is favorable for the fulfillment of the tasks set for the holder if this can be fixed in the tool and preferably braced. In particular, that can

Bracing done in such a way that the bearing back contacted particularly well and / or the partial surfaces of the bearing shells are particularly firmly pressed against a hand of the tool, so that here a coating is advantageously prevented.

Preferably, the tool according to the invention further

at least one plastic block on top of the

Lagerschalensäule is arranged to ensure, in particular at the upper end of the bearing shell column that all bearings below the surface of the

Electrolyte bath are located and reliably coated. The dummy shell at the lower end is eliminated, resulting in an increase in productivity.

Brief description of the drawings

Hereinafter, a shown in the drawings

Embodiment explained in more detail. Show it:

Fig. 1 is a perspective view of a holder;

FIG. 2 is a rear view of a tool according to the invention showing the tension of the associated holder; FIG.

FIG. 3 shows a section of the holder shown in FIG. 1 with further elements of a tool; FIG. and

4 shows a tool cover.

Detailed description of an embodiment of the invention

The holder 10 shown in Fig. 1, which also as

Rückenkontaktierung can be referred to, in the embodiment shown on four substantially parallel rails or strips 12, which are made of metal, to contact in pairs (not shown) bearing shells. The metallic strips are in the embodiment shown in slightly wider plastic strips

embedded, which are connected via numerous transverse struts 14 with each other and with a central plastic strip 16. Overall, for the embodiment shown, the holder 10 is made of plastic with the exception of the metal rails 12. This also applies in particular to those bolts 18 which are present in triplicate in the embodiment shown and in the embodiment shown in each case have a radially continuous slot which extends approximately in the direction of the strips 12, 16.

The holder shown is used in such a way that the bearing shells to be coated are built up in a columnar structure. In the embodiment shown, two columns are constructed in parallel and each contacted by the two lying on one side or the other of the central strip 16 metal strips 12. This contacting takes place, including a mechanical fixation on the tool particularly reliable and secure when the three bolts 18 were inserted through a wall of the tool, and in the

described slots of the bolt respectively, preferably wedge-shaped strips or pins introduced and

were clamped that the holder 10 is pressed against the mold wall, so that the interposed

Bearing shells both mechanically fixed, and are electrically contacted by the metal strips 12.

This tension of the holder in a tool is shown in FIG. The wedges 22 to be inserted into the slots of the bolts 18 may be provided on a plate 20 surrounding each of the wedges on three sides with a recess 24

having. In this way, the plate, for example, by inserting the bolt 18 in the recess 24 below each wedge 22 and subsequent displacement of the plate 20 such that each of the wedges 22 enters the respective slot, are braced. In this case, the plate 20 moves with respect to the bolts, in that shown in Fig. 2

Embodiment down, wherein the bolts are received in the laterally arranged by the wedges 22 portions of the recesses 24.

In Fig. 3 it is shown that the metal rails 12 are brought together in a particular upper region by a transverse connection 26 and connected to a power connection 28. In this area, the metal rails 12 are no longer embedded in the plastic of the receptacle 10. Further, in Fig. 3, a plastic block 30 is shown, which has on the one hand recesses for the upper end portions of the rails 12 and on the other serves to the constructed

To clamp bearing shells 32 axially. Further, by the plastic block 30, the distance to the air above the

Balanced electrolyte bath, so that in other words it is ensured that all bearing shells 32 are reliably below the surface of the electrolyte bath.

Finally, FIG. 4 shows a tool cover 34 in which the so-called robber cathode 36 is integrated in an advantageous manner. These are in the embodiment shown a few interconnected rods that in the range of (in Fig. 3 directed to the viewer)

Backings are arranged to produce a potential difference to the bearing back, which ensures that they are not coated. In the upper region of the lid 34 is a power connection 38 for the robber cathode 36th

provided to produce the described potential difference.

Claims

claims

1. tool for the galvanic coating of plain bearings with at least one cover (34) on which a

Robber cathode (36) is mounted.

2. Tool according to claim 1, further comprising at least one

Holder (10) for a plurality of bearing shells (32) to be galvanically coated with at least one strip (12) which is suitable for mechanically fixing and / or electrically contacting a plurality of bearing shells (32).

3. Tool according to claim 2,

By doing so, that is

a plurality of parallel, in particular an even number of strips (12) are provided.

4. Tool according to claim 2 or 3,

By doing so, that is

the holder (10) made of plastic and at least one strip

(12) is made of metal.

5. Tool according to one of claims 2 to 4,

By doing so, that is

the holder (10) can be fixed in the tool and

is preferably braced.

6. Tool according to one of the preceding claims, further comprising at least one plastic block (30).