WO2012163380A1

WO2012163380A1 - Device for thermal coating

Info

Publication number: WO2012163380A1
Application number: PCT/EP2011/006129
Authority: WO
Inventors: Oliver Methner; Eyuep Akin ÖZDENIZ
Original assignee: Daimler Ag
Priority date: 2011-06-03
Filing date: 2011-12-07
Publication date: 2012-12-06
Also published as: DE102011103487A1

Abstract

The invention relates to a device (1) for thermally coating inner walls of hollow bodies, comprising a feeding apparatus (2) for at least one coating material and a hollow torch shaft (3), which can be rotated about the longitudinal axis (L) of the torch shaft and on which a hollow inner torch (5) is arranged, which torch is designed in such a way that the coating material exits radially at a torch head (7) of the inner torch (5), wherein the coating material in the form of two wires (8) can be guided from the feeding apparatus (2) to the torch head (7) of the inner torch (5) through the torch shaft (3) and the inner torch (5) and an arc can be generated between the wires (8) at the torch head (7). According to the invention, contacting units (13) for electrically contacting the wires (8) are arranged outside of the torch head (7).

Description

Device for thermal coating

The invention relates to a device for thermal coating according to the

Features of the preamble of claim 1.

From the prior art, as described in DE 198 41 617 A1, a rotating wire arc spraying system for coating inner surfaces is known. The device for thermally coating the inner walls of hollow bodies comprises an inner injection device, which has a burner shaft rotatable about its longitudinal axis, at one end of which a supply device for coating media and at the other end of which an inner burner is provided. The internal burner is designed such that the coating media emerge radially. The internal burner is designed as a hollow wire arc internal burner, with a burner head, which has two outgoing from the supply means wires between which an arc is ignited and which further comprises a Verteilergasdüse, which is arranged so that the distribution gas radially emerges. The burner shaft is rotatably mounted in a holder and formed in the form of a hollow body, through which the wires are guided from the replenishment device to the burner head. The holder has a feed device for distribution gas which opens into the hollow burner shaft.

In the applicant's DE 10 2005 012 360 A1, the complete contents of which are hereby incorporated by reference, an arc wire burner is described. Of the

Arc arc torch for arc spraying comprises at least two burner tubes for supplying wire-formed electrodes, which in the direction of

coating surface of an object are passed through the burner tube. The wire is via a rotatably mounted, guiding and / or sliding elements

guided deflecting means, by means of which the wire is deformed in the elastic region. The invention is based on the object, an improved device for

specify thermal coating.

The object is achieved by a device for thermal coating with the features of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

A device for thermally coating inner walls of hollow bodies, also referred to as an arc wire spraying device, comprises a supply device for at least one coating material and a hollow burner shaft rotatable about its longitudinal axis, on which a hollow inner burner is arranged, which is designed such that the coating material on a burner head of

Inner burner radially emerges, wherein the coating material in the form of two wires from the supply device through the burner shaft and the inner burner to the burner head of the inner burner is feasible and an arc is ignited at the burner head between the wires.

According to the invention, contacting units for making electrical contact with the wires are arranged outside the burner head.

In internal burners according to the prior art, the contacting units are in

Burner head arranged near a region in which the arc is to be generated. By laying these contacting units out of the burner head, d. H. by their arrangement in an area outside the burner head, a more compact design of the internal burner, in particular realized by the burner head, d. H. a reduction of a diameter of the internal burner. This allows internal coating of smaller hollow bodies, i. H. inner walls of smaller diameter bores than is possible with internal burners of the prior art. Here, a consistently high layer quality can be achieved.

Since electrical leads are no longer to be led to the burner head, a component reduction is achieved. In addition, this is a larger free space in the

Internal burner provided, whereby, for example, a supply of a distributor gas to the burner head and a Verteilergasdüse and an arrangement of the

Distributor gas nozzle is optimized in the burner head. Furthermore, the wires heat up due to the flow of current between contact points of the wires in the area of the wires Kontaktiereinheiten and the burner head due to the length of the wires from the Kontaktierstellen to the burner head and due to an internal resistance of the wires, whereby a deflection of the wires in the inner burner, in particular in

Burner head is facilitated just before the arc generation and wear of a wire deflection or more such wire deflections is reduced.

By means of such a device, for example cylinder liners of

To coat internal combustion engines thermally with homogeneous spray coatings, whereby a friction reduction and thus a reduction in wear and a consumption optimization and a reduced carbon dioxide emissions can be achieved. Due to the small diameter of the inner burner, in particular of the burner head, cylinder liners of internal combustion engines are to be coated in this way, which have cylinders with a small diameter.

In addition, due to the small diameter of the inner burner, for example, connecting rods of internal combustion engines to coat, for example, an inner wall of a large eye of the connecting rod. Here, above all, the reduction of the bearing thickness made possible in this way, which permits a change of the geometry, and a

Weight saving allowed. While common bearing shells are between 2 and 4 mm thick, a suitable spray coat is up to about 200 [in thick. In addition, the change of geometry also enables a reduction of the stroke.

Conveniently, the contacting units are arranged outside of the internal burner. This makes it possible to carry out the entire inner burner with a correspondingly reduced diameter, so that the inner burner is also applicable for coating inner walls of hollow bodies, which have a small diameter and a high height, for example for coating cylinder liners of internal combustion engines, which cylinder with a have great depth, d. H.

which have a large stroke or piston stroke. In such cylinder, the inner burner is then fully inserted to fully coat the cylinder bore.

Preferably, the contacting units in the burner shaft or in a

Burner flange arranged, which connects the internal burner with the burner shaft. The burner stem is usually not introduced into the cavity whose Inner wall to be coated so that its diameter can be greater than the diameter of the inner burner. As a result, the contacting units are very well arranged in the burner shaft. Alternatively, the contacting units are arranged in the burner flange. By means of this burner flange of the inner burner is connected to the burner shaft or to connect, ie on the burner flange is preferably a releasable connection between the burner shaft and the inner burner created. The burner flange forms, for example, a transition from the burner shaft with a larger diameter to the internal burner with a significantly smaller diameter.

The burner flange is for example fixedly arranged on the burner shaft and the

Internal burner is then interchangeable, for example, against another internal burner, or the burner flange is fixed to the internal burner and interchangeable with the internal burner. In both cases, different internal burners are to be attached to the same burner shaft, for example, for a respective

Coating purpose to be able to use an optimal internal burner. Furthermore, the internal burner is exchangeable in this way, for example, in the event of wear against a new internal burner.

If the inner burner is firmly connected to the burner flange, then the inner burner is interchangeable, for example, even if the contacting units wear out, against a new inner burner, which accordingly has a new burner flange with new, unused contacting units. This allows for quick and inexpensive maintenance, thereby reducing downtime of the device

Maintenance are minimized. Alternatively, however, the burner flange may be fixedly connected to both the inner burner and the burner shaft, whereby it is merely formed as a transition or connecting part between the burner shaft and the inner burner.

The burner flange is usually not introduced into the cavity, analogous to the burner shaft, whose inner wall is to be coated so that its diameter can be greater than the diameter of the inner burner. In addition, the burner flange, if it is formed as a transition from burner shaft with a large diameter to the inner burner with a much smaller diameter, already largely a larger diameter than the inner burner anyway. As a result, the contacting units are very easy to arrange in the burner flange, since the required space is available here. Conveniently, the contacting units are each formed as a sliding contact, as a Kontaktierstift or as a bent Kontaktierführung. such

Contacting units allow a good and low-wear electrical contacting of the wires formed from the coating material, so that a proper operation of the device over a long period of use is ensured and necessary maintenance to replace worn contactor units are minimized.

Preferably, the contacting units can each be pressed against the respective wire by means of at least one spring element. The spring elements are each formed, for example, as a tension spring or a compression spring. In this way, the electrical contacting of the wires is further improved, since the contacting units are always pressed with a predetermined by the spring elements pressure on the wires. In this way, for example, sparks between the contacting units and the respective wire are prevented or at least reduced, which would lead to increased wear of the contacting units and to poor energy transfer to the wires. In addition, even with normal wear (in the normal operating condition of the burner) ensures a uniform contact,

Advantageously, an energy transfer from an electrical energy source to the contacting units via an arranged on the burner shaft electrical

Distribution unit. Alternatively, the distribution unit, for example, on

Burner flange, ie be arranged below the burner shaft, or in the connecting region between the burner shaft and burner flange. To this distributor unit, an external burner energy source can be connected, which may be part of the device, for example in the form of a generator or a welding power source, or which may be independent of the device, for example a power grid. By the burner-external power supply, a weight and dimensions of the burner, ie the inner burner and the burner shaft are reduced, whereby the burner is easier to handle, for example by means of a robot arm or a CNC axis, which is for example connected to the burner shaft and by means of which Internal burner can be inserted into each hollow body to be coated and in particular parallel to a rotational axis of the bore in the hollow body is movable. Conveniently, the electrical distribution unit on sliding contacts, which are formed for example as slip rings. In this way, the electrical energy from the electrical distribution unit can be transferred to the contacting units in the rotating burner shaft or burner flange. Alternatively, if the distributor unit is firmly connected to the burner shaft and / or the burner flange and also rotates, the electrical energy can be transmitted via the sliding contacts from the electrical energy source to the distributor unit.

Preferably, a wire deflection for deflecting the wires in the direction of an outlet opening of the burner head is arranged in the burner head. Exemplary embodiments of such wire deflections are disclosed, for example, in DE 10 2005 012 360 A1 of the applicant, whose entire contents are hereby incorporated by reference. Such a deflection of the wires is advantageous or necessary in order to optimize the arc, to prevent or minimize migration effects of the arc and to optimize a flow of the arc with the distribution gas, d. H. in particular to optimize an arrangement of the arc with respect to the Verteilergasdüse and the outlet opening. In this way, an exit of the

Coating material from the burner head in a predetermined direction, with a predetermined thickness and distribution and a predetermined speed ensured so that a homogeneous coating of the inner wall to be coated of the hollow body in a predetermined thickness and with a predetermined formation and composition of the applied spray layer is ensured.

Preferably, the wire deflection of ceramic or metal, in particular made of hard metal. In this way, the wire deflection is very resistant to wear, so that even over a long period of use a proper deflection of the wires is ensured and maintenance, maintenance and maintenance costs to replace the wire deflection are minimized.

In a particularly advantageous embodiment, the wire deflection has a

Cover on which is expediently also made of ceramic or metal, in particular made of hard metal. The wire deflection is formed, for example, ski jump-like and each has a guide channel for each wire. These guide channels are covered with the cover, so that the wires are enclosed in the guide channels each over an entire circumference and are guided, ie, it is prevented from escaping from the guide channels, whereby a plastic or elastic bending of the wires in the wire deflection takes place in order to deflect the wires in the direction of the outlet opening and lead. Due to the exact guidance and defined deformation of the wires in the wire deflection, the wire deflection can be made shorter; Advantageously, no completely rectangular or larger wire deflection is required. In this way, the wire deflection requires less space. The cover over the wire deflection is made possible by the laying of the contacting units out of the burner head. In burners according to the prior art, the contacting units are arranged in the region of the wire deflection, so that such a cover is not possible.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

Fig. 1 shows schematically an apparatus for thermal coating of

Inner walls of hollow bodies,

Fig. 2 shows schematically a perspective view of a burner flange, and

Fig. 3 shows schematically an internal burner with a burner flange.

Corresponding parts are provided in all figures with the same reference numerals.

FIG. 1 schematically shows a device 1 for thermal coating of

Inner walls of hollow bodies, not shown here, also as

Arc wire spraying referred to. The device 1 comprises a

Supply device 2 for at least one coating material and a hollow burner shaft 3 rotatable about its longitudinal axis L.

The burner shaft 3 is connected to a corresponding, not shown here drive for rotating the burner shaft 3. In the example shown here, the supply device 2, which has two wire rollers 4, arranged in the burner shaft 3, so that it rotates with the burner shaft 3. At a lower end of the burner shaft 3, a hollow inner burner 5 is arranged, which rotates together with the burner shaft 3 about its longitudinal axis L. This inner burner 5 is partially in the example shown schematically in Figure 1 in the

Burner shaft 3 inserted arranged. In the figures 2 and 3, another embodiment is shown in which the internal burner 5 fixed to a

Burner flange 6 is connected, via which the inner burner 5 with the

Burner shaft 3 is to connect, d. H. the burner flange 6 allows a detachable connection of the internal burner 5 with the burner shaft 3.

As a result, for example, various internal burners 5 are to be fastened to the same burner shaft 3 in order to be able to use an optimum internal burner 5, for example for a particular coating purpose. Furthermore, the inner burner 5 is in this way, for example, in the event of wear against a new

Internal burner 5 interchangeable. This allows fast and cost effective

Maintenance work, whereby downtime of the device 1 are minimized for maintenance purposes. Through the burner flange 6 is a transition between the

Burner shaft 3 formed with a large diameter to the inner burner 5 with a much smaller diameter.

The inner burner 5 is in each case designed such that the coating material on a burner head 7 of the inner burner 5, which at a lower end of the

Internal burner 5 is formed, radially emerges. The coating material can be guided in the form of two wires 8 from the supply device 2 through the burner shaft 3 and the internal burner 5 into the burner head 7 of the internal burner 5. For this purpose, the replenishing device 2 has a corresponding drive, for example for driving the wire rollers 4 or for driving another suitable feed device for the wires 8. In the burner head 7, an arc can be ignited between the wires 8.

Furthermore, in the burner head 7 in a manner not shown a

Distributing gas nozzle 9 arranged to supply a distributor gas to the arc. By means of the distributor gas is coating material, which is sealed by means of the arc of the wires, as a spray jet 10 through an outlet opening 1 1 in the burner head 7 through to be coated to the inner surface of the respective hollow body conveyed. In addition, in the burner head 7 in a manner not shown a formed example of ceramic or metal, in particular made of hard metal wire deflection 12 for deflecting the wires 8 in the direction of the outlet opening 11 of the burner head 7 is arranged. This wire deflection 12 is preferably designed as a two-part component, that is, it has in a manner not shown in more detail on a cover, which is expediently also made of ceramic or metal, in particular made of hard metal. Exemplary embodiments of wire deflections 12 are disclosed, for example, in the applicant's DE 10 2005 012 360 A1, whose entire contents are hereby incorporated by reference. Due to the design of the wire guide 12 made of ceramic or metal, in particular hard metal, the wire deflection 12 is very resistant to wear, so that even over a long

Period of use, a proper deflection of the wires 8 is ensured and maintenance, maintenance and maintenance costs to replace the

Wire deflection 12 are minimized.

The wire deflection 12 is formed, for example, ski jump-like and each has a guide channel for each wire 8. These guide channels are covered with the cover, so that the wires 8 are enclosed and guided in the guide channels in each case over an entire circumference, d. H. it prevents escape from the guide channels, whereby a plastic or elastic bending of the wires 8 takes place in the wire guide 12 to the wires 8 in the direction of

To divert the outlet opening 11 and lead.

Due to the exact guidance and defined deformation of the wires 8 in the

Wire deflector 12 is the wire deflector 12 shortened form it is

advantageously no completely rectangular wire deflection 12 is required. In this way, the wire deflection 12 requires less space.

Such a deflection of the wires 8 is advantageous or necessary to the

To optimize the arc, to prevent or minimize arc migration and to optimize the flow of the arc with the distribution gas. D. H. in particular to optimize an arrangement of the arc with respect to the Verteilergasdüse 9 and the outlet opening 11. In this way, an exit of the

Coating material from the burner head 7 in a predetermined direction, ensured with a predetermined thickness and distribution and a predetermined speed, so that a homogeneous coating of the inner wall to be coated the hollow body is ensured in a predetermined thickness and with a predetermined formation and composition of the applied sprayed layer.

To generate the arc between the wires 8, these are about

Contacting units 13 to apply electrical energy. These

Contacting units 13 for electrical contacting of the wires 8 are in the embodiments of the device 1 shown in the figures outside of the

Burner head 7 and also outside the inner burner 5 is arranged.

In the embodiment shown in Figure 1, the contacting units 13 are arranged in the burner shaft 3 and in the illustrated in Figures 2 and 3

Embodiments, the contacting units 13 are arranged in the burner flange 6. In both embodiments, the contacting units 13 are thus arranged in regions of the device 1, which are not to be introduced for coating the inner walls of hollow bodies in the respective hollow body, whereby a sufficient space for the contacting units 13 is available.

The contacting units 13 may be designed, for example, in each case as a sliding contact, as a contacting pin or as a bent contacting guide. Such contacting units 13 allow a good and low-wear electrical

Contacting the wires 8 formed from the coating material, so that a proper operation of the device 1 is ensured over a long service life and necessary maintenance to replace worn contacting units 13 are minimized.

Preferably, the contacting units 13, as shown here, in each case by means of at least one spring element 14 can be pressed against the respective wire 8. The

Spring elements 14 are each formed, for example, as a tension spring or a compression spring.

In this way, the electrical contacting of the wires 8 is further improved, since the contacting units 13 are always pressed with a predetermined by the spring elements 14 pressure on the wires 8. As a result, for example, sparks between the contacting units 13 and the respective wire 8 are prevented or at least reduced, which would lead to increased wear of the contacting units 13 and to poor energy transmission to the wires 8. An energy transfer from an electrical energy source 15 to the contacting units 13 takes place via an electrical distributor unit 16, which is arranged on the burner shaft 3 in the example shown in FIG. To this

Distributor unit 16 is a burner-external power source 5 can be connected, which is part of the device 1 in the example shown in Figure 1 and is designed for example as a generator. Alternatively, the device 1 for power supply, for example, with a power supply network as an energy source 15 can be coupled. Due to the burner-external power supply, a weight and dimensions of the burner, d. H. the internal burner 5 and the burner shaft 3, whereby the burner is easier to handle, for example by means of a robot arm, which is for example connected to the burner shaft 3 and by means of which

Internal burner 5 can be inserted into each hollow body to be coated and in particular parallel to a rotational axis of the bore in the hollow body is movable.

The distributor unit 16 has sliding contacts, for example, which are designed, for example, as slip rings. In this way, the electrical energy from the electrical distribution unit 16 to the contacting units 13 in the rotating

Burner shaft 3 or burner flange 6 transferable. Alternatively, if the

Distributor unit 16 is fixedly connected to the burner shaft 3 and also rotates, the electrical energy via the sliding contacts of the electric power source 15 to the distribution unit 16 transferable.

By means of such a device 1, for example, cylinder liners of

To coat internal combustion engines thermally with homogeneous spray coatings, whereby a friction reduction and thus a reduction in wear and a consumption optimization and a reduced carbon dioxide emissions can be achieved.

In prior art thermal coating devices, the wire bonding is located near a region where the arc is to be generated, i. H. right in the head of the burner. As a result, a large space is required in this area and in the entire burner, are to be laid by the appropriate electrical supply lines. Such burners according to the prior art therefore have a diameter of at least 60 mm.

By laying the contacting units 13 out of the burner head 7, ie by placing them in a region outside the burner head 7, in the embodiments shown here in the burner shaft 3 or in the burner flange 6, is a more compact design of the internal burner 5 realized, ie a reduction of a

Diameter of the inner burner 5. The inner burner 5 therefore has a diameter of less than 60 mm, for example, a diameter of about 50 mm.

It can be realized in this way also internal burner 5 with a diameter of only about 40 mm. This allows internal coating of smaller hollow bodies, i. H. inner walls of smaller diameter bores than is possible with prior art thermal coating devices. In this case, with the device 1 a consistently high layer quality can be achieved.

Due to the small diameter of the inner burner 5, inner walls of hollow bodies with a small diameter are to be coated in this way,

For example, cylinder liners of internal combustion engines, which have cylinders with a small diameter. In addition, due to the small diameter of the inner burner 5, in particular at a diameter of only about 40 mm, for example, to coat connecting rods of internal combustion engines, for example, an inner wall of a large eye of the connecting rods, which also in such

Components of the internal combustion engine, a friction reduction and thus a reduction in wear and a consumption optimization and a reduced

Carbon dioxide emissions of the internal combustion engine can be achieved.

For internal burners 5 with such a small diameter of, for example, only about 40 mm are further expediently wires with a smaller

Diameter to use, d. H. these have instead of the usual 1, 6 mm, which are still to be used even with the internal burners 5 with a diameter of about 50 mm, for example, only 1, 2 mm or only one millimeter in diameter. In addition, for a connecting rod coating other coating materials are to be used than for a cylinder liner coating, for example, coating materials

Copper base. By means of these other coating materials, it is easier to reshape the wires 8 from the coating material, so that even at a low level

Diameter of the inner burner 5 with a small space inside the

Inside burner 5, the deflection of the wires 8 is easily possible.

Since the entire inner burner 5 has the smaller diameter, the

Internal burner 5 also for coating of inner walls of hollow bodies can be used, which have a small diameter and a high height, for example, for coating cylinder liners of internal combustion engines, which cylinder with a have great depth, ie which have a large stroke or piston stroke. In such cylinder, the inner burner 5 is then fully inserted to the

Fully coat the cylinder liner.

In addition, since electrical leads are no longer to be guided to the burner head 7, a component reduction is achieved. Furthermore, this creates a larger free space in the internal burner 5, whereby, for example, a supply of the

Distributor gas to the burner head 7 and the Verteilergasdüse 9 and an arrangement of the Verteilergasdüse 9 is optimized in the burner head 7. For example, one is

Gas supply cross-section increases to the Verteilergasdüse 9, whereby a higher

Gas flow is possible.

In addition, the wires 8 are heated by the flow of current between Kontaktierstellen the wires 8 in the contacting units 13 and the burner head 7 due to the length of the wires 8 from the Kontaktierstellen to the burner head 7 and due to an internal resistance of the wires 8, whereby the deflection of the wires in the

Internal burner 5, in particular in the burner head 7 just before the area of

Arc generation is facilitated and wear of the wire guide 12 is reduced.

LIST OF REFERENCE NUMBERS

contraption

complementing means

torch sleeve

wire roll

internal burner

Burner

burner head

wire

Verteilergasdüse

spray jet

outlet opening

wire deflection

contacting

spring element

energy

Distribution unit longitudinal axis

Claims

claims

1. Device (1) for the thermal coating of inner walls of hollow bodies, comprising

- A replenishment device (2) for at least one coating material and

a hollow burner shaft (3) rotatable about its longitudinal axis (L),

on which a hollow internal burner (5) is arranged,

which is designed in such a way

the coating material emerges radially at a burner head (7) of the internal burner (5),

wherein the coating material in the form of two wires (8) of the

Supply device (2) through the burner shaft (3) and the internal burner (5) to the burner head (7) of the internal burner (5) can be guided and at the burner head (7) between the wires (8) an arc is ignited,

characterized,

in that contacting units (13) for making electrical contact with the wires (8) are arranged outside the burner head (7).

2. Device (1) according to claim 1,

characterized in that the contacting units (13) outside the

Internal burner (5) are arranged

3. Device (1) according to claim 1 or 2,

characterized in that the contacting units (13) are arranged in the burner shaft (3) or in a burner flange (6) which connects the internal burner (5) to the burner shaft (3).

4. Device (1) according to one of claims 1 to 3,

characterized in that the contacting units (13) each as a

Sliding contact, as a Kontaktierstift or as a bent Kontaktierführung are formed.

5. Device (1) according to one of the preceding claims,

characterized in that the contacting units (13) in each case by means of at least one spring element (14) to the respective wire (8) are pressed.

6. Device (1) according to one of the preceding claims,

characterized in that an energy transfer from an electrical energy source (15) to the contacting units (13) via an on the burner shaft (3) arranged electrical distribution unit (16).

7. Device (1) according to claim 6,

characterized in that the electrical distribution unit (16) has sliding contacts.

8. Device (1) according to one of the preceding claims,

characterized in that in the burner head (7) a wire deflection (12) for deflecting the wires (8) in the direction of an outlet opening (11) of the

Burner head (7) is arranged.

9. Device (1) according to claim 8,

characterized in that the wire guide (12) made of ceramic or metal, in particular made of hard metal is formed.

10. Device (1) according to claim 8 or 9,

characterized in that the wire deflector (12) has a cover.