WO2013030306A1

WO2013030306A1 - Method and device for cleaning coked cavities, more particularly valves in intake ports of a combustion engine

Info

Publication number: WO2013030306A1
Application number: PCT/EP2012/066914
Authority: WO
Inventors: Friedrich Sprügel; Alfons Urban; Iris KIELTSCH
Original assignee: Tunap Industrie Chemie Gmbh & Co. Produktions Kg
Priority date: 2011-08-31
Filing date: 2012-08-30
Publication date: 2013-03-07
Also published as: EP2751409A1; PL2751409T3; ES2617481T3; DK2751409T3; EP2565416A1; EP2751409B1

Abstract

The invention relates to a method for cleaning coked cavities, more particularly valves (10) in intake ports (10) of a combustion engine (14), involving the following steps: Introduction of a water-soluble cleansing powder (44) as a powder jet into a cavity to be cleaned by means of a compressed gas, simultaneous introduction of an aqueous liquid (48) into the cavity to be cleaned so that when the cleansing powder (44) is released into the aqueous liquid (48), a cleansing fluid forms in the cavity to be cleaned, and suction of the cleansing fluid and the introduced gas, together with the dirt particles dispersed therein, out of the cavity.

Description

METHOD AND DEVICE FOR CLEANING HAZARDOUS CAVES, ESPECIALLY OF VALVES IN ENTRANCE CHANNELS

A COMBUSTION ENGINE

The present invention relates to a method and a device for cleaning coked cavities, in particular of valves in intake passages of an internal combustion engine.

In internal combustion engines, such as gasoline and diesel engines impurities often occur in the intake ports and on the intake valves, which are caused in particular by lower-quality fuels and / or unfavorable operation of the engines. The impurities are mainly hard and soft as well as greasy carbon deposits, which interfere with engine growth more and more with increasing growth, because when opening the intake valves the required inlet cross sections are not reached anymore. If nothing is done against such deposits, massive faults in the inlet valves can occur, which means that the entire cylinder head of an engine has to be replaced.

The invention has for its object to provide a method and apparatus for cleaning coked cavities, in particular of valves in intake ports of an internal combustion engine or the simple handling easy removal of heavy impurities and deposits substantially without abrasion of the valve surface or the Inlet channel wall allows.

This object is achieved by the method according to claim 1 and the device according to claim 11. Advantageous developments and refinements of the invention are described in the respective subclaims. According to the invention it is thus provided that a water-soluble cleaning powder jet is introduced by means of a compressed gas into a cavity to be cleaned, and that at the same time an aqueous liquid is introduced into the cavity to be cleaned, so that by dissolving the cleaning powder in the aqueous liquid, a cleaning liquid in forms to be cleaned cavity, and that the cleaning liquid and the introduced gas is sucked with the dirt particles dispersed therein from the cavity.

By introducing water-soluble cleaning powder by means of an air flow into the cavity to be cleaned, it is possible to use the abrasive effect of the powder grains to dissolve impurities from the walls of the cavity to be cleaned. As a result of the subsequent dissolution of the powder in the liquid, a preferably alkaline cleaning liquid is formed which dissolves both dirt particles removed from the walls and dirt particles still on the walls or at least disperses them so that the dirt can be removed 100% during subsequent suction , The mechanical cleaning effect can be achieved by introducing the cleaning powder with compressed air into the cavity to be cleaned as a powder jet. In this way, a jet of compressed air can be produced which has a good abrasive effect on the contaminants on the walls of the cavity to be cleaned, the water surface being treated and the hardness of the cleaning powder being treated with care, by treating the metal surface of the valves and the inlet channels , So there is essentially no or only a small removal of the valve material.

For a particularly good cleaning effect of the water-soluble cleaning powder, which combines mechanical and chemical cleaning when it encounters soiling areas, it is particularly advantageous if the cleaning powder is composed of syrupy to dendritic bodies with a hydrophobized surface.

In particular, the cleaning powder by means of SiO 2 or by microencapsulation z. B. hydrophobic by means of organo-functional silanes. This ensures that the cleaning do not stick together powder particles so that the cleaning powder remains fluid and thereby remains transportable by means of an air flow.

Preferably, a cleaning powder having a particle size of 40 to 400 μιη, in particular from 40 to 200 μιη and preferably from 50 to 150 μιη used. Due to the neutralization energy in the solution of a solid liquor within an acidic aqueous liquid or a solid acid in an alkaline aqueous liquid, it is particularly advantageous if the cleaning powder contains a solid base such as sodium or potassium hydroxide, carbonates or bicarbonates. Mono-, di- or tricarboxylic acids, in particular, malic, citric or gluconic acids, can be used as solid acid.

However, it is also conceivable that the cleaning powder contains, in addition to or instead of a solid alkali or acid, inorganic salts such as metal halides, phosphates, sulfonates, silicates or borates.

It is also conceivable for the cleaning powder to contain organic pigments such as microencapsulated alcoholates, acetates, azoles, imidazoles or piperazine.

It is expedient to adapt the cleaning fluid to the particular cleaning powder used, the particle size and the microencapsulation. In the case of a solid alkali such as sodium carbonate, an acidic aqueous solution is used, in the case of an acid an alkaline solution. To achieve an optimum cleaning effect, it is advantageous to select the amount of acid or alkali in the cleaning fluid such that the cleaning powder presented dissolves without residue in this cleaning fluid within 1-5 seconds and the resulting solution has a pH of from 7-8. In order to guarantee complete dissolution of the granules, the cleaning liquid may further contain an organic solvent for dissolving the microencapsulation, preferably an alcohol. In addition, non-foaming, hydrotropic surfactants may be added to the cleaning fluid in order to optimally disperse the dirt particles and evacuate. The cleaning liquid adapted to the respective cleaning powder ensures that no solid particles remain in the inlet channels, which can lead to engine damage as a result of compression losses caused by scoring on the piston or cylinder wall. In order to optimize the cleaning effect of the method according to the invention, it is advantageous if the amounts of cleaning powder and aqueous liquid are coordinated so that the cleaning powder is completely dissolved in the aqueous liquid and dirt components are completely dispersed.

For a powerful cleaning due to the sandblasting principle, it is advantageous if the pressure gas provided for introducing the cleaning powder as a powder jet has a pressure of 0.5 bar to 3 bar.

According to the invention, a device for carrying out the above-described cleaning method according to the invention is provided with a cleaning jet probe having a first channel for introducing the water-soluble cleaning powder as a powder jet into the cavity to be cleaned by means of the compressed gas and a second channel for introducing the aqueous liquid into the Having to be cleaned cavity.

In order to be able to carry out a clean cleaning, it is expedient here if the device according to the invention further comprises a suction device for sucking off the cleaning liquid and the introduced gas with the dirt components contained therein from the cavity.

In order to avoid a mixing of the powder jet and the liquid jet, which ensures that the water-soluble cleaning powder does not clump during the exit from the cleaning jet probe, it is particularly expedient if outlet openings of the first and the second channel are arranged adjacent to one another and configured such that a leaking liquid jet and the exiting powder jet do not come into contact with each other. According to a practical embodiment of the invention, it is envisioned that the first channel of the cleaning jet probe can be connected to a compressed gas source via a suction lifter for the cleaning powder, while the second channel can be connected to a liquid source, wherein the suction port of the suction lifter for the cleaning powder a cleaning powder container is used.

For a simple cleaning of a plurality of inlet valves in corresponding inlet ducts in a cylinder head, which are usually arranged in a row, the apparatus for carrying out the method according to the invention further comprises an adapter device with at least one connection element, which has an input-side opening of a Seals inlet channel of a cavity to be cleaned and having an access channel to the inlet channel, and a cleaning Strahlsondenhaltevorrichtung has, which is tightly connected to a connection element so that the cleaning jet probe is sealed in the inlet channel is inserted, and having a suction port, which with the suction device is connected to suck the cleaning fluid and the introduced gas with the dirt contained therein from the inlet channel through the access channel.

In this case, it is expedient for the cleaning jet probe holding device for the sealed introduction of the cleaning jet probe into an inlet channel to have a rubber bellows which is in close contact with the cleaning jet probe at its one end and with the cleaning probe holding device at its other end.

The cleaning method according to the invention uses the energy of the compressed air powder jet, which leads to the separation of dirt on the wall on impact with the powder particles, together with the solution enthalpy to produce a highly effective cleaning liquid, in particular an alkali in which not only the cleaning powder is completely dissolved and thus kept liquid but also the dirt-dispersing action and the dirt-carrying capacity of the cleaning agent, so the highly effective cleaning liquid is used to remove the dirt components completely from the cavity to be cleaned. The invention will be explained in more detail below with reference to the drawing. Show it:

Figure 1 is a simplified schematic sectional view of an intake port of a

Internal combustion engine, such as a diesel engine;

Figure 2 is a simplified schematic sectional view of an inventive

Device for cleaning cavities, in particular for the intake passage and valve cleaning in internal combustion engines, during the cleaning process;

Figure 3 is a simplified schematic representation of a cleaning jet probe for simultaneously introducing a cleaning powder and an aqueous liquid into a cavity to be cleaned;

Figure 4 is a simplified detail view of outlet openings of a first and a second channel of the cleaning jet probe according to the invention;

Figure 5 is a simplified schematic representation of an adapter device with four connection elements, to which a cleaning Strahlsondenhaltevorrichtung according to the invention is connectable;

Figure 6 is a detailed schematic sectional view of an attached to a cylinder block adapter device together with the Reinigungsstrahlensonden- tevorrichtung according to the invention.

FIG. 1 is an example of a cavity to be cleaned, namely, an intake passage 10 in a cylinder head 12 of an internal combustion engine, such as a diesel engine 14, conventionally mounted on a corresponding cylinder block 16. An outlet opening 18 of the inlet channel 10 which opens into a cylinder, not illustrated in detail in the cylinder block 16, is conventionally closed by an inlet valve 20, which is guided in the cylinder head 12 by means of a corresponding valve guide 22 in accordance with the engine control, to release and close the opening 18 of the intake passage 10.

The intake ports 10 and intake valves 20 of diesel engines coke very strongly, as indicated schematically in FIG. Particularly affected are so-called swirl ducts (not shown in detail) which are used in modern diesel engines with four valves per cylinder in order to impart a twist to the gas mixture to be supplied to the cylinder, which should lead to improved mixing of air and injected fuel , In addition, the surface of the neck and the conical end portion of the inlet valve 20 are contaminated. The deposits in the inlet channels 10 and the inlet valves 20 are, in particular, soft, greasy carbon deposits.

According to the present invention, the cleaning of the inlet channels 10 and the inlet valves 20 is carried out by exposing the inlet-side openings 24 of the inlet channels 10 in the cylinder head 12 into the inlet channel 10 with a pulverized detergent together with an aqueous liquid under pressure, so that by dissolving the cleaning powder in the aqueous liquid forms a cleaning liquid in the cavity to be cleaned, the cleaning effect is optionally enhanced by the heating due to the heat of solution when dissolving the cleaning powder. FIG. 2 shows, in a simplified schematic sectional view, a device 26 according to the invention for cleaning cavities, in particular the walls of the inlet channel 10 and / or the surface of the inlet valve 20, as fastened on the side of the inlet-side opening 24 of the inlet channel 10 to the cylinder head 12.

The device 26 has a cleaning jet probe 28 (which is only partially shown in FIG. 2 and will be described in detail below with reference to FIG. 3), a suction device 30, an adapter device 32 and a cleaning jet probe holding device 34. The adapter device 32 is detachably fastened to the cylinder head 12 and seals the inlet-side opening 24 of the inlet channel 10 such that an access channel 36 for the passage of the cleaning jet probe 28 remains in the inlet channel 10. The cleaning probe holder 34 may be formed integrally or firmly connected to the adapter device 32, but it is also possible to provide a detachable connection such as a plug connection between the cleaning jet probe holder 34 and the adapter device 32 (as described in more detail below with reference to FIGS Figures 5 and 6 will be explained). For further sealing of the inlet channel 10 to the surroundings, a rubber bellows 38 is provided, which is in close contact with the cleaning jet probe 28 at its one end and with the cleaning jet probe holding device 34 at its other end. In this case, there must be a close contact between the rubber bellows 38 and the cleaning jet probe 28 only insofar as it is necessary to prevent leaking liquid with dirt particles. The cleaning jet probe holding device 34 has a suction connection 40, through which cleaning fluid and introduced gas with dirt components dispersed therein can be sucked out of the cavity through the suction device 30.

The cleaning jet probe 28 has a first channel 42 for introducing a water-soluble cleaning powder 44 as a powder jet into the cavity to be cleaned by means of a compressed gas and a second channel 46 for introducing aqueous liquid 48 into the cavity to be cleaned.

For cleaning contaminants 50 which have formed on a surface of the inlet valve 20 or on a wall of the inlet channel 10, the powder jet of the cleaning powder 44 is directed to the corresponding contaminants, wherein the impact of the cleaning powder 44 on the contaminants 50 similar to a sandblast An abrasive removal of dirt 50 takes place. Due to the additionally introduced aqueous liquid 48 comes after hitting the surface to be cleaned to a mixing of the cleaning powder 44 with the aqueous liquid 48, which additionally still a chemical cleaning due to the. By the Dissolving the cleaning powder 44 in the aqueous liquid 48 resulting cleaning liquid takes place. A detailed description of the cleaning process will be given later.

FIG. 3 shows a simplified schematic representation of the cleaning jet probe 28, which is connected via a liquid line 52 to a liquid source 54 and via a gas pressure line 56 to a compressed gas source 58. The cleaning jet probe 28 has a liquid jet tube 60 with the second channel 46 and a powder jet tube 62 with the first channel 42, through which the aqueous liquid 48 and the cleaning powder 44 are directed in a cleaning operation under pressure on the contaminants 50 (Figure 2). The liquid jet tube 60 and the powder jet tube 62 are shown in Figure 3 as straight tubes. In order to achieve optimum cleaning of the inlet valves 20 or of certain regions of the wall of the inlet channel 10, the powder jet tube 62 with the first channel 42 and the liquid jet tube 62 with the second channel 46 can be bent so that it optimally matches the geometry of the inlet channel 10 are. However, the curvature of the powder jet tube 62 with the first channel 42 should not be too great to avoid abrasion of the inner wall of the first channel 42 by the cleaning powder 44 guided in the first channel 42, or at least minimizing damage to the tube 62 to avoid.

The powder jet tube 62 has a diameter of 2 to 10 mm, preferably 4 to 8 mm and in particular 6 mm and is made of a resistant material such as hardened steel. By the air pressure line 56, the powder jet pipe 62 is supplied from the compressed gas source 58, a pressurized gas, preferably compressed air is used. Since the cleaning process is usually carried out in motor vehicle workshops, as a compressed gas source 58, a conventional compressed air source such as a compressor can be used. However, it is important that dried air is used to prevent clumping of the cleaning powder 44. Accordingly, when using a non-dried air pressure source additionally a drying device (not shown) can be interposed. The pressure of the compressed gas used is in a range of 0.5 bar to 3 bar. The cleaning powder 44 is stored in a cleaning powder container 64 and is sucked through a suction port 66 of a siphon 68 according to the Venturi principle in the compressed gas stream within the powder jet tube 62 and blown out together with the compressed gas stream as a cleaning powder jet from a first outlet opening 70 in the direction of the dirt 50 to be cleaned. The cleaning powder container 64 has a capacity of 250 mm to 500 mm. The compressed gas source 58 is preferably designed to deliver compressed gas at a pressure of up to 10 bar. In a cleaning operation, the compressed gas consumption at an operating pressure of 2 to 3 bar is about 170 1 / min. By the siphon 68, a pressure of 0.09 to 0.3 bar is generated in a cleaning operation within the cleaning powder container 64, the cleaning powder container 64 is thus under negative pressure. As the compressed gas line 56, a flexible hose can be used, which is designed for the gas pressure used.

The liquid jet tube 60 is also preferably made of metal and is supplied via the liquid line 52 from the liquid source 54 with an aqueous liquid which exits under pressure through a second outlet opening 72 as a liquid jet in the direction of the contaminants 50 to be cleaned (Figure 2). As the liquid source 54, a pump can be used which can be connected to a liquid reservoir. In addition, a liquid pressure cup can be used, which is pressurized by means of a compressed gas. The diameter of the liquid jet tube 60 is 0.5 mm to 5 mm, preferably 0.7 mm to 2 mm and in particular 1 mm. The pressure at which the aqueous liquid is forced through the liquid jet pipe 60 is 0.5 bar to 10 bar. At an operating pressure of 1 bar, the liquid consumption is 300 ml to 1 1 / min. Here, the liquid consumption is matched to the cleaning powder consumption per unit time so that the cleaning powder 44 is completely dissolved in the aqueous liquid 48 after hitting a wall in the inlet channel 10 and dirt components 50 are completely dispersed. To achieve this in an optimal manner, the diameter of the first channel 42 of the powder jet tube 62 is greater than the diameter of the second channel 46 of the liquid jet tube 60 at the liquid and gas pressure used, the size ratio between 2: 1 and 10: 1, preferably is between 4: 1 to 8: 1 and in particular 6: 1. The Tube length from the cleaning powder container 64 to the outlet openings 70, 72 is 200 mm to 300 mm.

Figure 4 shows a detailed view of the distal end of the cleaning jet probe 28 with the outlet openings 70 and 72 according to an embodiment of the invention. In order to prevent the exiting liquid jet and the exiting powder jet from contacting each other, the outlet openings 70, 72 and the distal ends of the liquid jet tube 60 and the powder jet tube 62 may be configured such that the liquid jet and the powder jet divergent from the outlet openings 70 , 72 emerge and run each other. For this purpose, the tubes 60, 62 may be mutually curved at their ends, but it is also possible to provide at the outlet opening 72 of the liquid jet tube 60 a nozzle (not shown) which produces a jet of liquid which is not in contact with the powder jet occurs. In addition, the outlet openings 70, 72 can also be designed so that the powder jet and the liquid jet converge towards one another and at a predetermined distance from the outlet openings 70, 72, which corresponds to a point of an object to be cleaned at a usual working distance. Finally, in a particularly simple embodiment, the tubes 60, 62 may simply be parallel at their distal end, with little mixing of the powder jet and the liquid jet being accepted. In order to reduce or prevent the abrasive effect of the powder jet on the inner wall of the powder jet tube 62, the inner wall of the powder jet tube 62 may be coated with a ceramic either entirely or only in the area of the outlet opening 70.

FIG. 5 shows a simplified schematic view of the adapter device 32 and the cleaning-jet probe holding device 34 on the cylinder head 12. In the embodiment of the adapter device 32 shown in FIG. 5, the adapter device 32 has four connection elements 74, which seal respective inlet-side openings 24 of the four inlet channels 10 of the cavity to be cleaned with the inlet valves 20 (not shown) and a respective access channel 36 to the respective inlet channel 10 have. The adapter device 32 is in this case detachably connected to the cylinder head 12, as indicated schematically by the screws 76. It is for the detachable connection particularly advantageous if the adapter device has fastening holes at the locations at which a screw connection of the cylinder head 12 with a valve cover (not shown) takes place. Thus, after removal of the valve cover, the fastening device used therefor, such as a screw / nut connection for releasably securing the adapter device 32 to the cylinder head 12 can also be used. However, other releasable connection types are conceivable, such as a magnetic connection or a plug connection with the aid of the inlet channels 10.

Although it is conceivable that the adapter device 32 is provided only for an intake passage 10 and formed integrally with the purge probe holding device 34, according to the invention, it is particularly advantageous if a plurality of connecting elements 74 corresponding to the number of intake ports 10 on one side of the cylinder head 12 is provided, wherein the connection elements 74 are adapted to provide a plug connection with the Reinigungsstrahlsondenhaltevorrichtung 34. As shown in FIGS. 5 and 6, in this case the outside diameter of the hollow cylindrical connection element 74 with the access channel 36 is matched to the inside diameter of the cleaning jet probe holding device 34, which is likewise designed as a hollow cylinder, so that a tight contact between a connection element 74 and the cleaning jet probe holding device 34 inserted thereon is achieved , Thus, after mounting the adapter device 32 by simply repositioning the cleaning jet probe holding device 34, the four inlet channels 10 and the inlet valves 20 (FIG. 2) shown in FIG. 5 can be cleaned.

FIG. 6 shows a schematic sectional view of the adapter device 32 with the cleaning jet probe holding device 34. Here, the suction port 40 is provided on a peripheral side of the cleaning blast probe holding device 34 to allow suction of the cleaning liquid and the introduced gas with the debris contained therein from the inlet channel 10 through the access channel 36 by means of the suction device 30. However, the arrangement of the suction port 40 is not limited to the arrangement shown in FIG. It is also possible that the Cleaning jet probe 28 and a suction channel are arranged parallel to each other. However, the arrangement shown in FIG. 6 is preferred according to the invention, since the cleaning jet probe 28, which is held by the rubber bellows 38, can be moved more easily and with greater clearance in the cleaning jet probe holding device 34 and therefore in the inlet channel 10.

In the following, a method for cleaning coked cavities, in particular the inlet channels 10 and the valves 20 of the internal combustion engine 14, as shown in Figure 2, will be described.

After removing a valve cover from the cylinder head 12, the adapter device 32 is first screwed onto the cylinder head 12. When cleaning the inlet valves 20 and an inlet channel 10 to be cleaned, care must be taken that the inlet valve 20 is reliably closed in order to prevent penetration of cleaning powder 44 and aqueous liquid 48 into the cylinder space. For cleaning an inlet valve 20 located in the inlet channel 10, the cleaning jet probe holding device 34 is plugged together with the cleaning jet probe 28 onto a corresponding connection element 74 and the cleaning jet probe 28 is inserted with its distal end into the inlet channel 10 until it encounters the soiled inlet valve 20 , Thereafter, the compressed air supply and the liquid supply is turned on, whereby the cleaning powder 44 emerges together with the aqueous liquid 48 at high speed from the outlet openings 70, 72 of the cleaning jet probe 60 and jet-shaped impurities 50 hits.

According to the invention, the combination of a cleaning powder jet 44 impinging on the contaminants 50 and the simultaneous supply of an aqueous liquid 48 results in both a mechanical and a chemical cleaning. In order to achieve a combination of mechanical cleaning and chemical cleaning, a water-soluble cleaning powder is provided according to the invention, which, after striking the contaminants 50, is present in the supplied aqueous liquid. is dissolved and forms together with the aqueous liquid a cleaning liquid, which then further causes a chemical cleaning of the valves 20 and the inlet channel 10.

In order to prevent the cleaning powder 40 from already dissolving or clumping in the cleaning powder container 64 due to the atmospheric moisture, the water-soluble cleaning powder 44 is composed of syrupy to dendritic bodies having a hydrophobicized surface. The hydrophobing of the cleaning powder 44 can be effected by silanization, by means of SiO 2 or by microencapsulation. In particular, the hydrophobing of the cleaning powder 44 takes place by means of organo-functional silanes. The cleaning powder has a particle size of 40 to 400 μιη, preferably from 40 to 250 μιη and in particular from 50 to 150 μιη on.

More preferably, the water-soluble cleaning powder 44 contains a solid base such as sodium hydroxide or potassium hydroxide, carbonates or bicarbonates. Here, the energy of the compressed gas powder jet, which leads to the dissolution of the powder on the wall of the inlet valve 20 or the inlet channel 10 for dirt dissolution, used together with the enthalpy of solution to produce a highly effective liquor, in which not only completely dissolved the liquor powder and thus liquid is held, but also the dirt-dispersing effect and the soil carrying capacity of the liquor, so the highly effective cleaning liquid is used to remove the dirt components completely from the cavity to be cleaned.

However, instead of the solid liquor or in addition to the solid liquor, the cleaning powder 44 may contain further cleaning agents such as metal halides, phosphates, sulfonates, silicates or borates, and especially sodium carbonate, potassium carbonate, potassium or sodium bicarbonate, borax, potassium hydrogen phosphate or silicate contain. In addition, instead of or in addition to the abovementioned cleaning agents, the cleaning powder 44 may contain organic pigments such as microencapsulated alkoxides, acetates, imidazoles or piperazine. The supplied aqueous liquid 48 is preferably an aqueous alkaline to slightly acidic solution. As already mentioned above, the amount of liquid supplied is matched to the amount of powder supplied in such a way that an optimal solution of the cleaning powder 44 in the aqueous liquid 48 and an optimal dispersion of the dirt components is ensured.

However, instead of using a solid liquor as cleaning powder 44, it is also possible to use a solid acid, such as mono-, di- or tricarboxylic acids, in particular, malic, citric or gluconic acid.

The aqueous liquid 48 is expediently adapted to the respectively used cleaning powder 44, its particle size and its microencapsulation. In the case of a solid alkali such as sodium carbonate, an acidic aqueous solution is used, in the case of an acid an alkaline solution. In order to achieve an optimum cleaning effect, it is advantageous to choose the amount of acid or alkali in the cleaning liquid such that the presented cleaning powder 44 within 0.1 s to 10 s, preferably of 0.5 s to 7 s, and in particular from 1 s to 5 s dissolves without residue in this cleaning liquid and the resulting solution has a pH of 7-8. In order to guarantee complete dissolution of the granules, the aqueous liquid 48 may further contain an organic solvent for dissolving the microencapsulation, preferably an alcohol. In addition, non-foaming, hydrotrope surfactants can be added to the aqueous liquid 48 in order to optimally disperse and remove the dirt particles. The aqueous liquid 48 adapted to the respective cleaning powder 44 ensures that no solid particles remain in the inlet channels 10, which can lead to engine damage as a result of compression losses caused by scoring on the piston or cylinder wall. According to the invention, therefore, a water-soluble cleaning powder 44 is conducted to contamination sites 50 in accordance with a sandblasting principle, wherein a chemical cleaning takes place after the solution of the cleaning powder 44 in the aqueous liquid 48. Due to the high pressure of the transport gas and the aqueous liquid 48, a strongly swirled water-air mixture is produced, which is sucked and disposed of via the inlet channel 10 through the access channel 36 and through the suction port 40 into the suction device 30. As a suction device 30 is suitable for this example, a wet-dry vacuum cleaner or a wet vacuum, as they are standard in motor vehicle workshops.

After the cleaning process, the compressed air supply can be switched off, so that only aqueous liquid 48 enters the inlet channel 10 in order to carry out a rinsing process. However, it is also conceivable that the supply of cleaning powder 44 is stopped, with only aqueous liquid 48 and compressed air entering the input channel 10. Furthermore, after switching off the supply of aqueous liquid 48, only a supply of compressed air without cleaning powder 44 into the inlet channel 10 can take place in order to dry the inlet channel 10 together with the inlet valve 20.

After cleaning the first inlet channel 10, the cleaning jet probe holder 34 is withdrawn from the connection element 74, the nub wave rotated until the inlet valve 20 of another inlet channel 10 is completely closed, and the cleaning jet probe holder 34 is fitted onto a corresponding corresponding connection element 74. Thereafter, the cleaning of the further inlet channel 10 and the inlet valve 20 takes place. After the completion of the cleaning operations, the adapter device 32 is removed again and the valve cover 12 is screwed onto the cylinder head 12.

Claims

claims

A method for cleaning coked cavities, in particular of valves (10) in inlet ducts (10) of an internal combustion engine (14), comprising the following steps:

Introducing a water-soluble cleaning powder (44) as a powder jet into a cavity to be cleaned by means of a compressed gas,

simultaneously introducing an aqueous liquid (48) into the cavity to be cleaned so that a cleaning liquid is formed in the aqueous solution (48) by dissolving the cleaning powder (44) in the cavity to be cleaned, and

Aspirating the cleaning liquid and the introduced gas with the dirt particles dispersed therein from the cavity.

2. The method according to claim 1, characterized in that the cleaning powder (44) is composed of sprichigen to dendritic bodies with a hydrophobized surface.

3. The method according to claim 1 or 2, characterized in that the cleaning powder (44) is hydrophobized by silanization, by means of SiO 2 or by microencapsulation.

4. The method according to any one of the preceding claims, characterized in that a cleaning powder (44) with a particle size of 40 to 400 μιη, preferably from 40 to 250 μιη and in particular from 50 to 150 μιη is used.

5. The method according to any one of the preceding claims, characterized in that the cleaning powder (44) a solid alkali such as sodium hydroxide or potassium hydroxide, carbonates or bicarbonates, or a solid acid such as mono-, di- or tricarboxylic acids, especially apples, lemons -, or contains gluconic acid.

6. The method according to claim 5, characterized in that as the aqueous liquid (48), an acidic liquid is used when the cleaning powder (44) has a solid Contains alkali and that an alkaline liquid is used as the aqueous liquid (48) when the cleaning powder (44) contains a solid acid.

7. The method according to any one of the preceding claims, characterized in that the cleaning powder (44) contains metal halides, phosphates, sulfonates, silicates or borates.

8. The method according to any one of the preceding claims, characterized in that the cleaning powder (44) contains organic pigments such as microencapsulated alcoholates, acetates, imidazoles or piparazine.

9. The method according to any one of the preceding claims, characterized in that the amounts of cleaning powder (44) and aqueous liquid (48) are coordinated so that the cleaning powder (44) is completely dissolved in the aqueous liquid (48) and dirt components completely be dispersed.

10. The method according to any one of the preceding claims, characterized in that for introducing the cleaning powder (44) provided as a powder jet compressed gas has a pressure of 0.5 bar to 3 bar.

11. Device (26) for carrying out the cleaning method according to one of the preceding claims, comprising a cleaning jet probe (28) having a first channel (42) for introducing the water-soluble cleaning powder (44) as a powder jet into the cavity to be cleaned by means of the compressed gas and a second channel (46) for introducing the aqueous liquid (48) into the cavity to be cleaned.

12. Device (20) according to claim 11, further comprising a suction device (30) for sucking the Reinigungsfiüssigkeit and the introduced gas containing therein contaminants from the cavity.

13. Device (26) according to claim 11 or 12, characterized in that outlet openings (70, 72) of the first (42) and the second (46) channel adjacent to each other and are configured such that an exiting liquid jet and the exiting powder jet do not contact each other.

14. Device (26) according to one of claims 11 to 13, characterized in that the first channel (42) of the cleaning jet probe (28) via a working according to the venturi suction (68) for the cleaning powder (44) to a compressed gas source (58 ), while the second channel (46) is connectable to a liquid source (54), the suction port (66) of the siphon (68) for the cleaning powder (44) being insertable into a cleaning powder container (64).

The apparatus (26) of any one of claims 11 to 14, further comprising:

an adapter device (32) having at least one connecting element (74) which seals an inlet-side opening (24) of an inlet channel (10) of a cavity to be cleaned and has an access channel (36) to the inlet channel (10), and - a cleaning jet probe holding device (34 ), which is tightly connected to a connection element (74) so that the cleaning jet probe (28) in a sealed manner in the inlet channel (10) is insertable, and having a suction port (40) which is connectable to the suction device (30) to suck the cleaning fluid and the introduced gas with the dirt components contained therein from the inlet channel (10) through the access channel (36).