DE102007017759A1 - Processing machine for an abrading and an anabolic processing - Google Patents

Abstract

The invention relates to a processing machine for the combined construction of a workpiece by thermal spraying and abrasive machining, comprising a spray chamber (1), wherein both the structure and the abrasive machining of the workpiece within the processing machine (1).

Description

The The invention relates to a processing machine for combined construction a workpiece through thermal spraying and abrasive machining.

such Machine tools with 3 axes of motion for combined construction a workpiece by thermal spraying of a building material and erosive, in particular Mechanical processing are known. They have a spray chamber in which a spray gun and a removal device, in particular a rotating milling tool located. In the injection chamber, the workpiece is subjected to a thermal spraying process constructed and alternately mechanically with a removal device worked eroding. All utilities, such. B. a Powder conveyor or a gas heater are located outside the panel of the Processing machine. In addition, similar combined facilities known, for. B. so-called CMB process (controlled metal build-up technology), where constructed by means of a laser cladding and then processed by high-speed milling becomes.

With The present invention is intended to such a processing machine be further improved.

This takes place according to the invention a processing machine with at least 5 axes of motion to the combined Structure of a workpiece through thermal spraying and abrasive machining comprising a spray chamber for thermal spraying, both the construction and the abrasive Machining the workpiece takes place within the processing machine. All major utilities such as As a gas generator, a gas heater or a suction are located are preferred within the casing of the processing machine.

by virtue of This configuration, the structure and the machining of the workpiece can be optimized. Furthermore allows this embodiment is a space-saving design of the entire Processing machine.

advantageous Further developments are specified in the subclaims.

A authoritative Further development of the present invention is that the axes of movement of the machine from at least 3 linear Motion axes and consist of at least 2 rotary axes of motion. In order to It is achieved that very complex contours in one clamping applied and eroded at any solid angles can be.

Farther are preferably the linear axes of movement of the spray gun and / or the removal device and the rotational movement axes associated with the workpiece. This ensures that the workpiece only for the purpose of positional delivery and can not be moved for the purpose of editing. The three-dimensional Movement during application and removal takes place only through the Ordering or Abtragwerkzeug that workpiece is thus at a standstill machined (coated and worn).

The Removal device is preferably integrated in the injection chamber, so that a very compact design of the processing machine can be realized can.

It But applications are also conceivable, where it is advantageous if the removal device spatially separated from the spray gun, but still within the processing machine, is arranged. In such a Case, the processing machine has at least one separate injection chamber for the Applying procedure and at least one separate processing chamber for the Removal process, so that the machining processes apply and ablate not mutually, z. B. can affect thermally negative.

Farther the spray gun and the removal device are in a preferred Embodiment with one and the same movement device method, so that spent only relatively little effort on the drives must become.

It But also applications are conceivable where the spray gun and the Removal device, each with a separate movement device so that the machining processes apply and Abtragen in the processing machine can run independently.

When Abtragverfahren come preferably mechanical removal methods like milling, Grinding, etc. are used. But they are also different in principle Removal methods such as thermal removal methods, ablation with ultrasonic vibrations etc. conceivable.

A more authoritative Further development of the present invention is that the Thermal spraying with steam as the main gas of the thermal Spraying performed becomes. For this purpose, in the processing machine continues to be a main gas producer arranged, which converts water into water vapor.

The main gas producer consists of one advantageous embodiment of a combined steam generator and a superheater. This two-stage heating has the advantage that the steam generator has not only a small volume of steam but also a high control accuracy of the vapor pressure and a fast start-up and shutdown, so that the requirements for a continuous process can be taken into account. The generated water vapor is then fed to a reheater and heated to the desired temperature for the spraying process.

Of the Steam generator consists of an advantageous embodiment a wound heating coil z. B. also from several spiral or meandering meandering, coiled tube coils are made can, whose ends are connected to a closed flow channel.

To A preferred development are the individual coils interconnected so that the water is the coils from the outside happened inside.

Especially It is advantageous if the water enters the outermost coil and exits from the innermost pipe beating. This has the advantage that entrained liquid drops in the narrower spirals of the inner coil better by the higher centrifugal forces there pressed against the wall and thereby vaporized, producing a dry vapor without liquid fractions is reached.

Of the in the direction of steam outlet at the end of the flow channel lying part of Coil is at a temperature far above the saturation temperature Temperature applied to achieve a direct overheating of the steam.

To In a preferred embodiment, the steam generator is in an off a material or alloy having a high thermal conductivity, preferably Aluminum, existing housing cast.

to Heating the steam generator are in the housing after a beneficial Design heating elements provided.

These Heating elements can advantageously from electric heating cartridges or flue gas-carrying Tubes exist.

The Heating elements are according to an advantageous development in the Cast body poured.

alternative can in the case Also provided holes for receiving the heating elements, in which the heating elements can be inserted.

Around to allow a particularly symmetrical heating, the heating elements preferably annular arranged between the coils.

alternative can the heating elements also wrapped around the coils and together with this in the body be poured.

Besides, they are advantageously in the body Temperature sensors provided which also the temperature of the individual Heating ranges can regulate.

Of the Melting point of the material surrounding the coils is advantageously sufficiently below the melting point of the coils and above the maximum operating temperature.

Around an enlargement of the heating surface to achieve According to a preferred embodiment, the coils are a corrugated or ribbed inner surface to have. Furthermore, these geometries cause a sputtering of the liquid or a separation between entrained liquid and vapor.

Farther can According to a preferred embodiment, the coils on their outside a support structure for anchoring in the body exhibit. This support structure can preferably be made from an outer ribbing consist.

There is the volume of the evaporating liquid greatly expands it is also advantageous if the cross section of the coils in the flow direction enlarged to a longer one To reach residence time. In addition, the connections between the individual coils are formed as chambers, the one Separation between entrained liquid and steam cause.

Of the body is advantageously surrounded by insulation.

Outside The insulation can according to a preferred embodiment, an annular sheath be arranged, which is flowed through by the water to be heated. As a result, on the one hand, the heat load Minimized environment and on the other hand, the supplied water be preheated. This cooling or preheating can also be achieved if the outer coils not be heated directly. The body gets outside through the injected liquid cooled.

the Steam generator is preferably a pump for supplying the upstream of the water to be heated. Furthermore, the steam generator an outlet valve in the form of an expansion nozzle downstream. this has the advantage that the control of the plant exclusively on the Pump and the set cross-section of the nozzle on the steam side done can. The steam generator is preferably to a temperature preheated and regulated between the saturation temperature and the Rewet temperature (Leidenfrosttemperatur) of the water in the Operating state is. Depending on the number of coils is the Flowed through area in the direction of the steam outflow of dry steam, the There overheated directly by a suitable temperature control of the body can be. Thereafter, the mass of water is fed, the vapor at the pressure difference between the operating pressure applied to the outlet valve and static pressure after the exhaust valve at the corresponding opening cross-section can flow out. alternative the outlet cross section may also consist of a control valve.

The Pump can work continuously or pulsating, the latter to a better evaporation in the two-phase flow area leads. With this management a quick start-up and shutdown is achieved.

If the total volume of the steam generator does not exceed two liters, so is also highest To press no danger potential for the Environment due to breakage of coiled tubing.

To In a preferred embodiment, the heating coil is in stand-by mode depressurized, which additionally increases the reliability.

Out the steam generator is preferably overheated over the saturation point Steam fed to a preferably multi-stage reheater. task the first stage is pure overheating of the main steam flow, task of the second stage the combined warming of powder / carrier gas stream and Main steam flow.

Of the above-described main gas generators can also stand alone or in any combination with other machines for Application come.

Of the Reheater advantageously has an inner tube and a Inner tube surrounding pressure tube, wherein the inner tube of a Heat conductor is surrounded, which has a spiral flow channel for the main gas forms. As a result of this configuration, the carrier gas with the metal powder and the main gas heated at the same time and at relatively high temperatures to be brought. Since the reheater, the carrier gas with the metal powder over a longer Route leads, can also use the carrier gas the metal powder over a longer one Route to be preheated.

To In an advantageous embodiment, the heating conductor surrounds the inner tube a spiral.

Of the Heat conductor is advantageously made of an inner, on the inner tube adjacent and an outer, on Pressure tube adjacent resistance heating element. For easier installation however, a small gap is allowed.

Of the Heating conductor is preferably with an electrically non-conductive Surrounded by insulation. This allows direct contact of the electrical conductive Steam with the heating conductor.

There is also the jacket of the heating element made of stainless steel or an alloy Nickel, chromium and molybdenum, such as Inconel or Hasetloy, which is an excellent blend corrosion resistance, good machinability and high temperature resistance and can withstand stress corrosion cracking well.

The Pressure tube is advantageously of a ceramic insulation Surrounded by a heat radiation and a related thermal stress on the environment largely to prevent.

Around Thermal insulation to better isolate the reheater, the insulation arranged in an outer tube be.

advantageously, is the outer tube double-walled and in the wall is a coolant, such as As water, out.

If the heating conductor is subdivided into at least two sections with Different voltages can be supplied, can be a segmentation of the Heizwendel be achieved, so that a variable preheating of the Metal powder or the carrier gas possible is and the heat flow can be adapted to the respective circumstances.

According to one preferred embodiment, the heating element to compensate for thermal stress be only partially attached to the inner tube or the pressure tube.

The Hot gas generators are preferably at least 20 cm long. Conveniently, the length is in here present application, however, about 1.2 m.

Of the Cross section of the flow channel formed between inner tube and pressure tube can change after an advantageous development, z. B. expand or contract. This can be z. B. by a change the slope of the heat conductor done. This allows the flow speed and thus the heat transfer adapted to the temperature difference between carrier gas and heat conductor and one over the length uniform exchange heat flow be achieved. Furthermore This can also optimize the pressure loss in the flow channel.

Of the Reheater is in two stages according to a preferred embodiment built up. It serves in the first stage of the reheater the Inner tube for forming a flow channel between the heating conductor and pressure tube and as a displacement body, while in the second stage, the inner tube is flowed through by a gas / powder mixture, to heat up this mixture.

in this connection It is particularly advantageous if the inner tube in both stages straight, so that no powder deposits or unwanted separations of the gas / powder mixture result.

If individual larger particles should form at the end of the second stage of the steam heater a sieve with smaller holes than the diameter of the narrowest Cross section of the nozzle provided, which retains the particles and clogs prevented.

Of the above-described reheater can also be used alone or in any combination with other machines for Application come.

After this the gas / powder stream has left the reheater, it becomes one Supplied to the expansion nozzle.

These expansion nozzle possesses a convergent according to a preferred development and a divergent area with a narrowest one in between Cross-section and its inner contour has the shape of a single-shelled Hyperboloids whose generatrix is a straight line.

Around the flow behavior To further improve, the divergent and / or the convergent Extend area with a header element.

To a preferred embodiment, the inner contour of the expansion sleeve with a gaseous one or liquid wall-wetting film coated become. The main task of this film is to cool the expansion nozzle to to increase the service life and the temperature of the core flows to the limit of temperature resistance of the nozzle material introduce.

For monitoring of the operating state, a pressure sensor can be arranged in front of the expansion nozzle be.

The can be described above expansion nozzle also in isolation or in any combination with others Machine tools are used.

conditioned by the injection process, there are some problems. That is how it is in the processing of metal powder, the risk of a dust explosion, which must be avoided at all costs. In addition, a contact should the operator with the metal powder should be avoided as possible to a health impairment excluded.

Out For this reason, according to an advantageous embodiment, the injection chamber is divided into two functional areas, one of which is the one Accommodates components that serve to avoid an explosive atmosphere and dissipate the introduced thermal energy and impurities, and of which the other receives those components, which for carrying out the injection process and the machining process are required.

There during the injection process larger quantities Powders accumulate in the spray chamber, must accumulate powder in potential Corners or fluidic dead spaces the process chamber reliable be avoided. These could otherwise ignite by sparks or hot shavings or in the most extreme case caused by whirling to a dust explosion. That's why in the injection chamber advantageously bellows with stainless steel fins and a wetting, laminar water curtain arranged. The bellows strip off the dirt particles, leaving them in the lower area the processing machine fall. The lower area is replaced by a the walls wetting laminar water curtain kept clean. The water is channeled through holes into a manifold that ensures that on the entire length the same amount of water available stands. Through an outlet, the water reaches the spray chamber wall. This creates a continuous laminar water curtain.

The water-forming water is collected according to a preferred embodiment and fed to a collecting container to be promoted from there, preferably by means of a lifting pump to a water treatment plant to who the.

The Processing plant preferably consists of a centrifuge, a Belt filter or a vacuum belt filter which, if required, a pre-separator upstream.

Farther is the spray chamber connected to an exhaust system, which in the spray chamber atmosphere floating dust particles sucks as well as resulting gases to a wet scrubber leads.

Around ensure that the components used for explosion protection work properly, sensors are provided which the function monitor these components and in case of failure of one of these components, the processing machine put in a safe state.

When additional Safety against the effects of a dust explosion is to relieve pressure in a wall of the injection chamber, preferably in the cabin roof, a rupture disc arranged for one regulated reduction of the pressure wave ensures. In addition, the pressure over the Separators escape.

In order to the process room is accessible from the outside and the other allows observation of the interior, the injection chamber by means of a sliding door provided with a disc lockable. To the disc of dirt To keep clean, the water curtain is also integrated in the sliding door.

Around Continue to ensure safe operator protection from the effects a tool breakage, a dust explosion and excessive noise pollution to ensure, the spray chamber is complete encapsulated, and the disc of the sliding door is made of soundproofing Glass.

Because of of the sound pressure in the spray chamber of approx. 100-140 dB (A) and also to increase safety Explosions is the glass of the sliding door made of laminated safety glass, which is composed of several layers.

In addition, can the laminated safety glass on the outer side still with a Be provided polycarbonate disk.

There the starting substrate for must be tempered, the thermal spraying process is in the Spray chamber arranged a heatable substrate holder.

The measures described above for the spray chamber can also in isolation or in any combination with others Machine tools are used.

The Heating of the substrate holder can be used by in the substrate holder Cartridge heaters, by a radiation source integrated in the substrate holder or by inductive heating. Dependent the thermal conductivity of the component, the component size and in particular the component height must be the supplied Energy to be adjusted. With increasing component height must the temperature at the substrate increases become. The temperature at the surface of the component can by a suitable sensor z. B. a thermal imaging camera or pyrometer be determined.

Because a warming up the substrate holder negative on the accuracy of the processing machine would affect is the substrate holder by an insulating plate, preferably made Synthetic resin, glass fiber o. The like., Opposite the processing machine isolated.

Of the substrate holder described above can also be used alone or in any combination with other machines for Application come.

to advancement the spray material is a powder conveyor provided, the Powder continuously metered into a gas stream of carrier gas. As a carrier gas is preferably oxygen-reduced air is used, but it can almost also any other gaseous medium can be used, z. Nitrogen. Preferably, the gaseous medium is inert and particularly dry.

To In a preferred embodiment, oxygen-reduced air passes through the withdrawal of oxygen from compressed air (compressed air) generated. in this connection it is possible adjust the oxygen content. Because of the desired inertization is the oxygen content preferably less than 3 This oxygen-reduced Air will follow to a pressure equal to or higher than the system pressure compressed during spraying and preferably stored in a buffer tank.

When Main gas for thermal spraying will be cold gas spraying or kinetic Compacting preferably used as water vapor.

The Use of said carrier gas and main gas during thermal spraying can also be unique be used without the components described in connection or Method.

The powder conveyor advantageously comprises a turntable, the powder to a Entnah mestelle promotes, where it is taken from the carrier gas.

Around the level in the powder container to monitor is in the container a capacitive sensor installed. This allows monitoring during the filling as well as the removal. Preferably, the sensor outputs an analog signal to determine the fill level to be able to.

Preferably, the powder container expands shortly above the transfer point of the powder plate so that the powder is loosened before dosing ( 9 , No. 49). Subsequently, the powder may optionally be fed through a bore to the turntable. In addition, by moving z. B. a stirrer, the powder removal can be facilitated.

Around a homogeneous and steady stream of carrier gas powder to ensure, the flow rate is a combination of any gas flow meter with a Coriolis mass flowmeter certainly. The Coriolis mass flowmeter is as a straight tube system with a straight flow passage educated. Furthermore is the flow passage advantageously free of internals. This prevents separation or deposition of the solid components. In addition, since particle flows very have an abrasive effect and can severely damage the internals in a short time through one as possible straight and installation-free flow path increases the service life and the measuring accuracy of the measuring device. If appropriate Material selection of the measuring tube and the aggregate and / or at a lower flow rate may depend on the measuring tube from the bending radii also have a curved shape. The first Gas flow meter is mounted in the gas supply line in front of the powder conveyor. The Coriolis mass flowmeter is between the powder conveyor and the nozzle assembled. About that can out leaks can also be detected with the two flowmeters by operating the system without powder.

In order to even while the injection process of the powder supply can be refilled, is after a advantageous embodiment, a powder supply provided, which divided into two sections, passing through a powder lock are separated from each other. Thus, from the one section powder be removed while in the other section powder is refilled.

In order to The powder lock can reliably close the powder lock, even at very high pressures a seal and a conical closure. Because of a Such a design can be a seal solely due to the prevailing Printing done.

Around the powder conveyor to fill can while the spray break of the powder conveyor from a storage container refilled become. In combination with the powder lock, this is also during the Operation possible.

To In a preferred embodiment, the powder with a carrier gas in the powder conveyor transported. So that the powder as completely as possible from carrier gas a separator can be used. This separator has the task of the reservoir Separate incoming powder-gas mixture, so that the powder after down into the powder conveyor can fall and the gas can escape or be sucked.

Of the above described powder conveyor can also be alone or in any combination with others Machine tools are used.

To In a preferred embodiment, a cyclone is used as a separator. A cyclone preferably consists of a round housing tangential inlet at the top and a gas outlet, as Immersion tube is concentrically mounted in the lid. The entering Gas flow describes a screw Benförmig down running Circular path. Since the cyclone is closed at the bottom, the overall direction is reversed the gas flow, wherein the screwing motion is maintained. To prevent already separated particles from being whirled up again either the dust collector must be deep enough below the reversal point of the gas flow or a so-called apex cone is used. This apex cone is mounted just below the cone exit, so only still a ring-shaped There remains a gap through which the separated powder passes into the collecting tank can. Another advantage of a cyclone is the simple design and that the cyclone, with a suitable design, withstands high pressures.

There a cyclone very fine powder does not completely precipitate, can in the Gas outlet in addition a filter can be used. This filter can, for. B. from a Flies or a sintered material.

Of the Abscheider described above can also be used alone or in any combination with other processing machines are used.

As a result, the powder conveyor can be filled from a storage container, it is possible to carry out the filling under a protective gas atmosphere or oxygen-reduced atmosphere. This is especially important for powders that tend to dust or easily oxidize. A white terer advantage is that no moisture can get into the powder.

To In a preferred embodiment, the reservoir consists of a container a supply line (x), an output (y) and a connection (z) for Pressurization or venting has. The connections Supply line carrier gas and exit are down and at the bottom connected to a device which receives the powder-like one Water jet pump.

To In a preferred embodiment of the storage container, the connections are supply line, pressurization and venting equipped with a centrifugal separator and a filter. In the case, that powder is pushed back, the valves or pressure reducers are not contaminated.

To a preferred embodiment of the reservoir, the supply line can be heated so that the flow behavior is improved or the powder moisture can be removed.

The Reservoir described above can also be alone or in any combination with others Machine tools are used.

to process monitoring Can a video camera be used to remove defects z. B. voids or irregularities in the surface z. B. after face milling to be able to recognize due to too little material order.

To In a preferred embodiment, the process monitoring can also be performed by a Thermal camera respectively. This is additional the possibility a local overheating Prevent or delamination of the layers early to recognize. Defects can Thus recognized and reworked or the defective areas are removed and rebuilt.

The process monitoring described above can also be alone or in any combination with others Machine tools are used.

Further Details, features and advantages of the invention will become apparent the following description with reference to the drawings. Show it:

1 an overview of the processing machine according to the invention,

2 : the schematic structure of the processing machine,

3 a view of the injection chamber,

4 : the bellows arranged in the spray chamber in the extended and retracted state,

5 Fig. 3: a cross section showing the supply of the water required for the water curtain,

6 FIG. 3 is a view of the rear wall of the injection chamber with a tool magazine flap arranged therein. FIG.

7 : A plan view of the arranged in the spray chamber sliding door

8th FIG. 3: a cross section showing the structure of the disc arranged in the sliding door, FIG.

9 a side view of the sliding door,

10 : a schematic view of the substrate holder with integrated heating,

11 a cross section through the steam generator,

12 a cross section through the reheater,

13 a cross section through the expansion nozzle,

14 a schematic view of the powder conveyor, and

15 Two cross sections through the powder supply with closed or opened powder lock.

In The following description is the processing machine according to the invention for the combined construction of a workpiece by thermal spraying and erosive machining described in detail.

The main components of the inventive processing machine for the combined construction of a workpiece by thermal spraying and abrasive machining are a spray chamber 1 , a major gas producer 2 , a powder conditioner 3 as well as a water treatment plant 4 ,

In the spray chamber 1 even a workpiece is constructed by a thermal spraying process and processed alternately with a mechanical removal method.

Of the Structure of the workpiece with building material by means of a thermal spraying method known in principle.

In the method described here, the thermal spraying is carried out with water vapor as the main gas of a thermal spraying process. The generation of water vapor takes place by means of a steam generator integrated in the processing machine 5 , which in addition to a small volume of steam has a high control accuracy of the vapor pressure and a fast up and down behavior to meet the requirements of a continuous machining process.

The generated water vapor is then in a reheater 6 heated to the desired temperature for the spraying process, combined with the preheated carrier gas / powder mixture and an expansion nozzle 7 fed. There, the particles are strongly accelerated by a supersonic gas flow and with high kinetic energy to a substrate 8th injected, where they form a solid bond.

Out the pure process of the injection process out some Problems. So there is a danger in the processing of metal powder a dust explosion, which must be avoided at all costs. Furthermore should contact the operator with the metal powder as possible be avoided to a health impairment excluded.

Furthermore, the high gas velocities at the expansion nozzle cause an extreme sound level in the spray chamber 1 of 100-140 dB (A), which must be damped by appropriate measures.

The condensing steam leads the spray chamber 1 constantly heat to be derived and reused as much as possible in the process to avoid unnecessary loss of energy.

Around To meet these requirements is the processing machine in detail, as follows.

The spray chamber 1 has two functional areas. On the one hand, the pure explosion protection assemblies, whose essential task is to avoid an explosive atmosphere to dissipate the introduced thermal energy and remove impurities, to avoid any dangerous enrichment. Secondly, the pure process assemblies that supply and control the actual injection process with the required media.

The individual modules are in the 1 and 2 summarized.

As the injection process larger amounts of powder in the spray chamber 1 accumulate powder must accumulate in possible corners or fluid dead spaces of the spray chamber 1 reliably avoided. Otherwise, they could ignite due to sparks or hot chips or, in the most extreme case, could cause a dust explosion due to whirling up.

This will be in the upper (dynamic) area of the spray chamber 1 through bellows 9 ( 3 ) achieved with stainless steel fins.

The bellows 9 have a wiper edge 10 on, for the removal of dirt particles 11 serves, so that these in the lower area of the injection chamber 1 fall ( 5 ). The lower (static) area is defined by the walls of the spray chamber 1 wetting laminar water fog 12 kept clean ( 5 ). The water is drilled through holes in a manifold 13 directed. This ensures that the same amount of water is available over the entire length. Through a spout 14 the water reaches the walls of the spray chamber 1 where a continuous, laminar water curtain 12 arises.

The one in the injection chamber 1 located powder particles are bound to the water and fed to a sump, from which they use a lifting pump to the water treatment plant 4 be encouraged.

Because the injection chamber 1 with a sliding door 15 and a tool magazine door 16 is provided, there are particular difficulties with regard to the dust accumulation on such movable components.

The 6 and 7 show how these assemblies with a laminar water curtain 12 be flushed over. At the downwardly opening tool magazine flap 16 ( 6 ) becomes the water curtain 12 maintained during tool removal. This ensures that throughout the entire injection chamber 1 Dust deposits are avoided.

Also more in the spray chamber 1 Additional machine elements, such as the machine bed, swivel rotary table and slide guides, can be additionally sprayed through the water curtain 12 or a rinse cleaned and cooled to room temperature, so that heating by the steam can be avoided. A heating of the machine bed and the Schlittenfüh ments would also adversely affect the accuracy of the machine tool.

Remaining dust particles, which are in the spray Chamber atmosphere hovering, over an exhaust air system, which ensures a constant flow through the process space 1 provides, sucked off and a wet scrubber 17 fed. The air is passed through gaps z. B. sucked on the spindle slide from the upper and rear working space. The air drawn in through the gap acts as a barrier air, which means that no particles or gases can penetrate.

A centrifuge with cooler 18 It serves to remove the dirty water from the water curtain 12 and the wet scrubber 17 comes to clean and cool. The dirty water is transferred through a lifting pump into a dirty water tank 19 directed. From there it gets through the centrifuge 18 in which the solid particles are separated, into a clean water tank 20 directed. The pure water is through a recooler in the pure water tank 20 kept constant at 20 ° C. The recooler consists of two heat exchangers. The first heat exchanger preferably carries the waste heat to the feed water of the steam generator 5 to. The second heat exchanger dissipates the remaining waste heat into the environment.

Of the Loading condition of the centrifuge can indirectly via the be applied to be applied drive power. This measurement takes place following the following steps:

First step:

The Centrifuge is in unloaded condition. In this condition will the needed Energy for decelerating the centrifuge in relation to a defined Time interval determined. The measurement of the required energy can be used for Example about a Current measurement at the brake resistors respectively. It would be also possible to measure over the braking torque of the frequency converter of the drive motor takes place.

Second step:

Of the Values thus determined serve as the reference value for the empty centrifuge and is stored as a reference parameter in the memory of the machine control.

Third step:

The Centrifuge is in loaded condition. The measurement in the first Step is repeated and the determined value is compared with the value in Memory stored reference value compared. The difference between the two values are then a measure of the load the centrifuge

If one of the explosion protection components such as water fog 12 , Recirculation system or wet scrubber 17 should fail, appropriate sensors ensure that the machine is immediately brought into a safe operating condition.

As additional security against the effects of a dust explosion is to pressure relief in the roof of the spray chamber 1 a rupture disk 21 integrated, which together with the wet separator channel ensures a controlled reduction of the pressure wave.

Special importance in terms of reliability comes the sliding door 15 to the injection chamber 1 to. On the one hand, it is intended to allow access and observation of the process, and on the other hand to ensure safe operator protection against the effects of a tool breakage, a dust explosion and excessive noise pollution. It is therefore on the one hand in the water curtain 12 integrated and impact-resistant to EN 12417 (safety of machine tool machining centers).

Because of the in the spray chamber 1 occurring sound pressure of about 100-140 dB (A), is the injection chamber 1 completely enclosed, and also the sliding door 15 is with a sound-insulating disc 22 executed. The lateral sealing is done by seals 23 ( 7 ). The sliding door 15 moves in its closing movement on the seals 23 on and compresses them. At the upper and lower interface each sit a lowering seal 24 , Shortly before the closing point becomes a trigger 25 the lowering seal 24 actuated by a stop. A rubber lip of the lowering seal 24 extends and thus seals the gap.

The sound-insulating pane 22 is made up of several discs. On the side of the spray chamber a laminated safety glass is used. The glass is resistant to the abrasive behavior of the powder particles, but this disc exists 22 the impact test according to EN 12417 not. Therefore, in addition, a Polycarbonatscheibe operator side is 26 used in the sound insulation composite.

The workpiece itself is located on the heatable, designed as a swivel rotary substrate holder 8th because the starting substrate must be tempered for the thermal spraying process. This is done either by heating cartridges 27 which are in the substrate holder 8th are screwed in or around or through a in the substrate holder 8th integrated radiation source. Alternatively, the substrate holder 8th or the workpiece are also heated inductively. The power supply takes place by means of a slip ring 28 directly through the swivel rotary table.

The swivel rotary table must have the waste heat be removed from the substrate heating, because a heating of this assembly would adversely affect the accuracy.

Therefore, the substrate holder becomes 8th ( 10 ) through an insulating plate 29 insulated from synthetic resin / fiberglass. The remaining heat, which passes through the insulating plate 29 transported by heat conduction, is via a system of cooling ducts 30 derived in a cooling water system.

essential Part of the overall system is the system for generating and overheating the steam that forms the process gas of the spraying process. The Plant for steam generation must be characterized by a fast start-up and shutdown allow a cyclic steam extraction without cache.

The steam generator 5 consists of several spirally wound coils 31 ( 11 ), which are interconnected and connected at the ends to a closed flow channel. Preferably, the flow channel is flowed through from outside to inside. This has the advantage that entrained liquid drops in the narrower coils of the inner coil 31 be pressed by the higher centrifugal forces there better against the wall and thereby vaporized, whereby a dry vapor can be generated without liquid fractions.

The steam generator 5 is in a body 32 cast in aluminum. In this case 32 For heating electric heating cartridges or flue gas pipes are poured or subsequently introduced through vertical holes. The heating is ring-shaped between the coils 31 arranged. Each of the heating zones is covered by several, in the housing 32 regulated temperature sensors. Alternatively, the coils can 31 also be wrapped with heating conductors and in the housing 32 be poured. Casting material other than aluminum, other alloys or materials with high thermal conductivity in question, the melting point sufficiently below the melting point of the coils 31 and must be above the maximum operating temperature. The pipe snakes 31 themselves may consist of concentric tubes or tubes with corrugated or ribbed inner surface for enlargement of the heating surface. To get a better fixation in the body 32 to reach, the tubes may also have an outer ribbing and / or a support structure fixedly connected to the pipes.

Since the volume of the evaporating water greatly expands, it is also appropriate to the cross section of the coils 31 to increase in the flow direction to achieve a longer residence time. In addition, the connections between the coils can 31 be carried out as small chambers, which cause a separation between entrained water and steam.

The outer jacket of the steam generator 5 forms a pressure-resistant container, which is suitably insulated. Outside the insulation, an annular jacket can be attached, which is flowed through in a spiral shape by the liquid to be fed, whereby the heat load of the environment is minimized and the water is preheated. This cooling or preheating can also be achieved if the outer coils are not heated directly. The body is cooled externally by the injected liquid.

The regulation of the steam generator 5 takes place exclusively via a pump 34 and the set cross section of an exhaust valve on the steam side. The steam generator 5 is preheated and controlled to a temperature between the saturation temperature and the rewet temperature (Leidenfrosttemperatur) of the water in the operating state. Depending on the number of coils 31 As well as the temperature of the body, the area in the direction of the steam outflow flows through dry steam, which can be overheated directly there by a suitable temperature control.

After that the mass of water is fed, the vapor at the pressure difference at the outlet valve between operating pressure and static pressure after the outlet valve at the corresponding opening cross-section escape can. Alternatively, the outlet cross-section can also be from a nozzle with a fixed Cross section exist. The operating pressure and thus the outflowing steam mass flow hang then from the amount of water fed in as well as the steam temperatures in the overall system.

The Water supply can be either continuous or pulsed, the latter leading to better evaporation in the two-phase flow regime leads.

With this management, a fast start-up and shutdown is achieved. Exceeds that in the coils 31 enclosed volume moreover not 2 liters, so there is no danger potential for the environment even at high pressures as a result of breakage of the coils 31 in front. The pressure will be after switching off the pump 34 abruptly dismantled. Another advantage in terms of reliability is that the steam generator 5 is kept depressurized in stand-by mode.

For this steam generator 5 will the be overheated steam already above the saturation point of the two-stage reheater 6 fed. Task of the first stage is the pure overheating of the main gas stream, task of the second stage is the combined heating of powder / Trägergastrom and main gas stream.

The heating of the reheater 6 via heat conductors consisting of resistance heating wires 35 which are electrically insulated embedded in a jacket made of stainless steel or Inconel. This allows direct contact of the electrically conductive water vapor with the heating conductors 35 , The heating conductors 35 are spirally around an inner tube 36 and on the inside of a pressure-resistant pressure tube 37 designed so that they form a spiral flow channel. The spiral arrangement is only one-sided on the pressure tube 37 fixed to ensure a free longitudinal expansion of the inner assembly and the mechanical stress of the hot heat conductor 35 to minimize.

Due to the design, the minimum length of the reheater is 6 at about 20 cm, however, expediently, the reheater in the present application, however, about 1.2 m long.

The cross section of the flow channel can be changed by changing the pitch of the spiral heating conductors 35 over the length of the reheater 6 be reduced or increased, the flow velocity and thus the heat transfer to the temperature difference between the gas and the heating conductor 35 and to achieve a uniform heat exchange current over the length.

In addition, the slope allows the heating conductor 35 also an optimization of the pressure loss in the flow channel.

Another way to adjust the heat flow is to heat conductors 35 into individual segments, which are supplied with different voltages.

Especially the second reheater 6 installed in a very temperature sensitive part of the processing machine (Z-slide) is the reheater 6 from a ceramic insulation 38 surrounded, which also has a spiral-flow of coolant through double jacket of an outer tube 39 is actively cooled.

The inner tube 36 of the reheater 6 used in the first stage as a pure displacement body and support the inner heating conductor 35 for the formation of the spiral flow channel. In the second stage, the powder / carrier gas passes through it and heats it to the optimum mixing temperature with the main gas stream. It is particularly advantageous that the inner tube 36 is straight, so that no Pulverablagerun conditions or unwanted separations of the gas / powder mixture can take place.

If still in the inner tube 36 should form larger particles, is the bottom outlet of the reheater 6 with a sieve 40 ( 12 ) which retains the particles and clogs the subsequent expansion nozzle 7 prevented.

The flow is then in the expansion nozzle 7 accelerated to supersonic speed, whereby the particles are injected onto the substrate with high kinetic energy. The expansion nozzle 7 itself is structured in three parts ( 13 ). In a mixing chamber 41 the main gas stream and the powder / carrier gas stream are mixed. Together they will then be in the expansion nozzle 7 , which has the form of a single-walled hyperboloid on its inside, accelerated to supersonic speed. To the expansion nozzle 7 can still have a header element 42 connect, which serves for further acceleration and - supported by an additional steam injection - the formation of a parallel beam. In addition, in the expansion nozzle 7 a water feed 43 be provided. Through the water, the main gas flow and the expansion nozzle 7 to be self-cooled.

The operating condition is determined by a pressure sensor in front of the expansion nozzle 7 or monitored in the supply line. In normal operation, it is in front of the expansion nozzle 7 based on the water supply in the steam generator 5 a constant pressure. If the pressure increases with constant water supply, there is a blockage of the expansion nozzle 7 in front. If the pressure falls. Either a fault in the water feed or a leakage in the steam supply is the cause. To ensure process reliability, therefore, the amount of steam is also measured.

The powdered spray material is passed through a powder conveyor 44 steadily metered into a gas stream. Nitrogen is preferably used as the carrier gas, but it is also possible to use almost any other gaseous medium. The detailed structure of the powder conveyor 44 show the 14 , From a powder supply 45 is about a turntable 46 Promoted metal powder to a sampling point. In the turntable 46 is a groove 47 arranged, in which the supplied powder is located. At the sampling point, a carrier gas stream is coaxial with a powder tube 48 passed along. The carrier gas stream whirls in a groove 47 located on metal powder and tears it into the powder tube 48 With. The carrier gas metal powder stream is subsequently to the expansion nozzle 7 directed. To get a hold of the powder between powder supply 45 and turntable 46 to avoid is the outlet 49 from the powder supply 45 widened conically on the plate side.

In addition, there is an O-ring around the suction point 51 let in, which limits the suction area and seals.

Around the homogeneous and steady carrier gas powder stream to ensure, the throughput is determined with a Coriolis mass flowmeter.

A powder lock 52 can on the powder supply 45 be mounted, with the during the injection process powder can be refilled. It seals the powder supply 45 to an intermediate chamber 53 during the filling process. So can the intermediate chamber 53 be filled with powder during the working process. After the filling process, the intermediate chamber 53 again subjected to working pressure. As soon as the pressure in the intermediate chamber 53 the pressure in the powder supply 45 has adjusted, the powder lock 52 be opened and the powder falls into the powder supply 45 ,

Particular attention is paid to the design of the sealing mechanism between powder supply 45 and intermediate chamber 53 which must reliably close even at very high pressures. This is a conical closure 54 against a seal 55 pressed. This arrangement is chosen so that the sealing takes place solely due to the prevailing overpressure. The necessary mechanism for moving the conical closure up and down 54 is then responsible only for the movement itself. For the movement of the lock 54 a translatory movement is needed. Either a translatory drive is already used directly (pneumatic drive) or a rotational movement is converted into a translational movement ( 15 ).

The The preceding description of the present invention is only to for illustrative purposes and not for the purpose of limiting the Invention. Within the scope of the invention are various changes and modifications possible, without departing from the scope of the invention and its equivalents.

1

injection chamber

2

Main gas producers

3

Pulveraufbereiter

4

investment for water treatment

5

steam generator

6

reheater

7

expansion nozzle

8th

substrate holder

9

bellow

10

stripping

11

dirt particles

12

water curtain

13

distributor

14

outlet

15

sliding door

16

Tool magazine flap

17

wet scrubbers

18

centrifuge

19

Clean Water Tank

20

Recovery tank

21

rupture disc

22

disc

23

poetry

24

drop seal

25

trigger

26

polycarbonate lens

27

Cartridge Heater

28

slip ring

29

insulation

30

cooling channels

31

coil

32

casing

33

Cartridge Heater

34

pump

35

heating conductor

36

inner tube

37

pressure pipe

38

insulation

39

outer tube

40

scree

41

mixing chamber

42

intent element

43

water supply

44

powder Feeder

45

powder storage

46

turntable

47

groove

48

powder tube

49

outlet

51

O-ring

52

powder lock

53

intermediate chamber

54

conical shutter

55

poetry

Claims (78)

Processing machine with at least 5 axes of movement for the combined construction of a workpiece by thermal spraying and abrasive machining comprising at least one injection chamber for thermal spraying, characterized in that both the structure and the abrasive machining of the workpiece takes place within the processing machine. Processing machine according to claim 1, since characterized in that the axes of motion consist of at least 3 linear axes of motion and at least 2 rotary axes of motion. Processing machine according to claim 1 or 2, characterized characterized in that at least 2 rotary axes of motion in the Movement device for the workpiece lie. Processing machine according to one of claims 1 to 3, characterized in that at least 3 linear axes of motion in the movement device for the spray gun are lying. Processing machine according to one of claims 1 to 4, characterized in that at least 3 linear axes of motion in the movement device for the removal device lie. Processing machine according to one of claims 1 to 5, characterized in that the abrasive machining with the Removal device takes place in the spray chamber. Processing machine according to one of claims 1 to 5, characterized in that the abrasive machining with the Removal device outside the injection chamber takes place. Processing machine according to one of claims 1 to 7, characterized in that the spray gun and the removal device be moved with one and the same movement device. Processing machine according to one of claims 1 to 7, characterized in that the spray gun and the removal device each with a separate movement device are moved. Processing machine according to one of claims 1 to 9, wherein furthermore a main gas generator ( 2 ) is provided for the conversion of water into water vapor. Processing machine according to claim 10, wherein the main gas producer ( 2 ) a steam generator ( 5 ) and a reheater ( 6 ). Processing machine according to claim 11, wherein the steam generator ( 6 ) of a plurality of spirally wound, concentrically arranged pipe coils ( 31 ), whose ends are connected to a closed flow channel. Processing machine according to claim 12, wherein the individual coils ( 31 ) are connected to each other in such a way that the water the pipe coils ( 31 ) from outside to inside. Processing machine according to claim 12 or 13, wherein an odd number of coils ( 31 ) is provided and the water down into the outermost coil ( 31 ) and at the top of the innermost coil ( 31 ) exit. Processing machine according to one of claims 11 to 14, wherein the steam generator ( 6 ) in a housing made of a material or an alloy with a high thermal conductivity, preferably aluminum ( 32 ) is poured. Processing machine according to claim 15, wherein in the housing ( 32 ) Heating elements ( 33 ) are provided. Processing machine according to claim 16, wherein the heating elements ( 33 ) consist of electric heating cartridges or flue gas pipes. Processing machine according to claim 16 or 17, wherein the heating elements ( 33 ) in the housing ( 32 ) are poured. Processing machine according to claim 16 or 17, wherein in the housing ( 32 ) Holes for receiving the heating elements ( 33 ) are provided. Processing machine according to one of claims 16 to 19, wherein the heating elements ( 33 ) annularly between the coils ( 31 ) are arranged. Processing machine according to one of claims 16 to 19, wherein the heating elements ( 33 ) around the coils ( 31 ) and together with these in the housing ( 32 ) are poured. Processing machine according to one of claims 15 to 21, wherein in the housing ( 32 ) Temperature sensors are provided. Processing machine according to one of claims 15 to 22, wherein the melting point of the housing ( 32 ) forming material sufficiently below the melting point of the tube ( 31 ) and above the maximum operating temperature. Processing machine according to one of claims 12 to 23, wherein the coils ( 31 ) have a corrugated or ribbed inner surface. Processing machine according to one of claims 12 to 24, wherein the coils ( 31 ) on its outside a support structure for anchoring in the housing ( 32 ) exhibit. Processing machine according to claim 25, wherein the Anchoring consists of an outer ribbing. Processing machine according to one of claims 12 to 26, wherein the cross section of the coils ( 31 ) increases in the flow direction. Processing machine according to one of claims 12 to 27, wherein the connections between the individual coils ( 31 ) are formed as chambers, which cause a separation between entrained water and steam. Processing machine according to one of claims 25 to 28, wherein the housing ( 32 ) is surrounded by a pressure-resistant container, which is provided to the outside with an insulation. Processing machine according to claim 29, wherein outside the insulation is an annular jacket is arranged, which is flowed through by the water. Processing machine according to one of claims 11 to 30, wherein the steam generator ( 5 ) a pump ( 34 ) is connected upstream of the supply of water. Processing machine according to claim 31, wherein the pump ( 34 ) works continuously or pulsating. Processing machine according to one of claims 11 to 32, wherein the steam generator ( 5 ) An outlet valve is connected downstream. Processing machine according to one of claims 11 to 33, wherein the total volume of the steam generator ( 5 ) does not exceed two liters. Processing machine according to one of claims 11 to 34, wherein the steam generator ( 5 ) is depressurized in stand-by mode. Processing machine according to one of claims 11 to 35, wherein the reheater ( 6 ) an inner tube ( 36 ) and an inner tube ( 36 ) surrounding pressure tube ( 37 ), and wherein the inner tube ( 36 ) of a heating conductor ( 35 ), which forms a spiral flow channel for the main gas. Processing machine according to claim 36, wherein the heating conductor ( 35 ) the inner tube ( 36 ) surrounds a hospital. Processing machine according to one of claims 36 to 37, wherein the heating conductor ( 35 ) is surrounded with an electrically non-conductive insulation. Processing machine according to one of claims 36 to 38, wherein the heating conductor ( 35 ) from an inner, on the inner tube ( 36 ) and an outer, at the pressure tube ( 37 ) adjacent resistance heater consists. Processing machine according to one of claims 36 to 39, wherein the heating conductor ( 35 ) is surrounded by a jacket which made of stainless steel or an alloy of nickel, chromium and molybdenum, such as. As Inconel exists. Processing machine according to one of claims 36 to 40, wherein the pressure tube ( 37 ) of a preferably ceramic insulation ( 38 ) is surrounded. Processing machine according to claim 41, wherein the insulation ( 38 ) in an outer tube ( 39 ) is arranged. Processing machine according to claim 42, wherein the outer tube ( 39 ) is double-walled and in the wall, a coolant is guided. Processing machine according to one of claims 36 to 43, wherein the heating conductor ( 35 ) is divided into at least two sections, which can be supplied with different voltages. Processing machine according to one of claims 36 to 44, wherein the heating conductor ( 35 ) only at certain points on the inner tube ( 36 ) or the pressure tube ( 37 ) is attached. Processing machine according to one of claims 11 to 45, wherein the reheater ( 6 ) is at least about 20 cm, preferably 1 m long. Processing machine according to one of claims 36 to 46, wherein the cross-section of the between inner tube ( 36 ) and pressure tube ( 37 ) formed flow channel changes. Processing machine according to claim 47, wherein the change of the cross section is effected by a variable length of the heating conductors ( 35 ) is achieved. Processing machine according to one of claims 11 to 48, wherein the reheater ( 6 ) is constructed in two stages. Processing machine according to claim 49, wherein in the first stage of the reheater ( 6 ) the inner tube ( 36 ) as a support of the inner heat conductor ( 35 ) and flows through in the second stage of a powder / steam mixture to the to heat this mixture. Processing machine according to one of claims 49 or 50, wherein the inner tube ( 36 ) runs straight in both stages. Processing machine according to one of claims 49 to 51, wherein at the end of the second stage a sieve ( 40 ) is provided. Processing machine according to one of claims 11 to 52, wherein following the reheater ( 6 ) an expansion nozzle ( 7 ) arranged. Processing machine according to claim 53, wherein the expansion nozzle ( 7 ) has a convergent and a divergent region with a narrowest cross-section therebetween and the contour is in the form of a single-shell hyperboloid whose generatrix is a straight line. Processing machine according to claim 54, wherein the convergent and / or divergent region is provided with an attachment element ( 42 ) is extended. Processing machine according to one of claims 53 to 55, wherein the inner contour of the expansion nozzle ( 7 ) is coated with a gaseous or liquid wall wetting film. Processing machine according to one of claims 53 to 53, wherein in front of expansion nozzle ( 7 ) A pressure sensor is arranged. Processing machine according to one of claims 1 to 57, wherein the injection chamber ( 1 ) is divided into two functional areas, one of which accommodates those components which serve to avoid a potentially explosive atmosphere and dissipate the introduced thermal energy and impurities, and of which the other receives those components which are used to carry out the injection process and the Machining process are required. Processing machine according to one of claims 1 to 58, wherein in the injection chamber ( 1 ) Bellows ( 9 ) with stainless steel fins to prevent accumulation of powder and a wetting, the walls wetting, laminar water fog ( 12 ) for keeping and cooling the spray chamber ( 1 ) are arranged. Processing machine according to claim 59, wherein the water curtain ( 12 ) is collected and fed to a collecting container, from there, preferably by means of a lifting pump, to a water treatment plant ( 4 ) to be promoted. Processing machine according to one of claims 1 to 60, wherein the injection chamber ( 1 ) is connected to an exhaust air system, which sucks in the pressing chamber atmosphere floating dust particles and a wet scrubber ( 17 ) feeds. Processing machine according to one of claims 58 to 61, wherein sensors are provided which the function of the components, which serve to avoid an explosive atmosphere and Monitor the introduced thermal energy and impurities and in case of failure of one of these components, the processing machine switch off. Processing machine according to one of claims 1 to 62, wherein in a wall of the injection chamber ( 1 ) a rupture disc ( 21 ) is arranged. Processing machine according to one of claims 49 to 63, wherein the injection chamber ( 1 ) by means of a with a disc ( 22 ) sliding door ( 15 ) which can be closed in the water curtain ( 12 ) is integrated. Processing machine according to claim 64, wherein the injection chamber ( 1 ) is completely encapsulated and the disc ( 22 ) the sliding door ( 15 ) consists of soundproofing glass. Processing machine according to claim 65, wherein the glass of the sliding door ( 15 ) is a laminated safety glass, which is composed of several layers. Processing machine according to claim 66, wherein the laminated safety glass on the outer side with a polycarbonate disc ( 26 ) is provided. Processing machine according to one of claims 1 to 67, wherein in the injection chamber ( 1 ) a heatable substrate holder ( 8th ) is arranged. Processing machine according to claim 68, wherein the heating of the substrate holder ( 8th ) through into the substrate holder ( 8th ) used heating cartridges ( 27 ), one in the substrate holder ( 8th ) integrated radiation source or by inductive heating takes place. Processing machine according to one of claims 68 to 69, wherein the substrate holder ( 8th ) by an insulating plate ( 29 ), preferably made of synthetic resin, glass fiber o. The like., Is isolated from the processing machine. Processing machine according to one of claims 1 to 70, wherein for conveying the spray material, a powder conveyor ( 44 ) is provided, which do the powder in a gas stream of carrier gas do Siert. Processing machine according to claim 71, wherein the carrier gas Nitrogen is. Processing machine according to one of claims 71 to 72, wherein the powder conveyor ( 44 ) a turntable ( 46 ), which conveys the powder to a sampling point where it is entrained by the carrier gas. Processing machine according to one of claims 71 to 73, wherein a Coriolis mass flow meter is provided to the homogeneity and continuity of the carrier gas powder flow to ensure. Processing machine according to one of claims 1 to 74, wherein a powder supply ( 45 ) is provided, which is divided into two sections. Processing machine according to claim 75, wherein the two sections are passed through a powder lock ( 52 ) are separated from each other. Processing machine according to claim 76, wherein the powder lock ( 52 ) a seal ( 55 ) and a conical closure ( 54 ) having. Processing machine according to claim 58, wherein the loading state of the centrifuge ( 18 ) is determined via a comparison measurement.