EP3568261B1 - Blasting probe for introducing a granular blasting material into a cavity - Google Patents

Description

The present invention relates to a blasting probe according to the preamble of independent claim 1 for introducing a granular blasting material into a cavity, in particular for cleaning it, as well as a device for cleaning cavities which is provided with a blasting probe according to the invention. Such a beam probe is from the document U.S. 2,739,424 known.

From the DE 10 2010 039 696.6 a device for cleaning coked cavities, in particular inlet ducts and valves of an internal combustion engine is already known, which has a first probe which is provided at its front end with one or more nozzles for injecting an alkaline liquid into a cavity to be cleaned and which its other end is connected to the pressure side of a pump, the suction side of which can be supplied with an alkaline liquid. The alkaline liquid to be introduced into the cavity to be cleaned, for example into an inlet channel of a valve of an internal combustion engine, can be formed from a mixture consisting of a solvent and an alkali in solid form. When using such an alkaline liquid, it is possible to inject it into the cavity to be cleaned through nozzles arranged radially on the probe.

From the EP 2 565 416 A1 Another device is known for cleaning coked cavities, in particular inlet ducts and valves of an internal combustion engine, in which a cleaning jet probe has a powder jet pipe in addition to a liquid line, through which a blasting material is introduced into the cavity to be cleaned by means of compressed air in such a way that the granular blasting material is similar like sandblasting removes dirt from the walls of the cavity to be cleaned. Since, at the same time as the granular cleaning powder, a solvent is introduced into the cavity through a liquid line in the cleaning jet probe in order to form a cleaning liquid that removes the dirt, the abrasive effect of the cleaning powder serves to prepare and support the cleaning process by means of cleaning liquid.

If the cleaning of the cavity is to be carried out in a two-step process, which is the case when cleaning the inlet channels and valves of an internal combustion engine allows easier handling in a workshop with the engine installed, it is difficult, however, to direct the cleaning powder jet emerging from the axial outlet of the powder jet tube onto all areas of the walls of the cavity to be cleaned.

One possibility of controlling the direction of the cleaning powder jet is to bend the exit area of the powder jet tube so that the powder jet also has a radial component in addition to an axial component. In order to be able to apply the cleaning powder completely in the circumferential direction to a cylindrical cavity in this way, it is necessary, however, to be able to rotate the powder jet tube 360 around its longitudinal axis, which is practically impossible in narrow inlet channels.

the EP 2 848 367 A1 shows a jet nozzle unit with a cylindrical jet nozzle tube, which can be connected with its rear end to a jet center feed and which has a nozzle outlet opening at its front end in the jet direction, to which a conical deflection device is assigned.

the US 2010/0212157 A1 relates to a method for peening surfaces and describes a blasting material nozzle which has a radial nozzle opening at its front end to which a flat baffle plate is assigned. The rear end of the blasting material nozzle is connected to a blasting material guide piece that can be connected to a blasting material supply line.

the JP 2002-239909 A describes a nozzle device for blasting abrasive grains with compressed gas onto the inner surface of a medium-sized to small machine part. The nozzle device comprises a tubular nozzle body, at the outlet end of which a tubular assembly part with an impact body is attached, the flat impact surface of which is arranged obliquely to the longitudinal axis of the nozzle body and is assigned to a radial nozzle opening to provide granular blasting material in a cavity with which it is possible to ensure, even with narrow cavities, that all the walls of the cavity with the one used for its cleaning granular blasting material can be applied in order to completely remove the dirt.

This object is achieved by the beam probe according to claim 1.

Advantageous refinements and developments of the invention are described in the subclaims.

According to the invention, a blasting probe for introducing a granular blasting material into a cavity for cleaning it has a blasting tube, the outlet end of which is assigned a blasting nozzle which has a radial outlet opening, which is assigned a baffle which is arranged obliquely to its opening surface and obliquely to the longitudinal axis of the blasting tube . This ensures that the blasting material transported with compressed gas, in particular compressed air, through the blasting tube of the blasting probe is deflected over the impact surface in the radial direction in such a way that it exits the blasting tube of the blasting probe not only to the front, but also to the side.

The use of a jet nozzle according to the invention at the outlet end of the jet probe thus provides an angled jet of shot which can be guided over the entire circumferential area by simply rotating the jet pipe about its longitudinal axis. Since the beam tube of the beam probe does not have any bends, it can be completely rotated 360 ° even in the narrowest cavities into which it can just be inserted, so that the walls of the narrowest cavities, in particular the inlet channels of inlet valves of internal combustion engines, can be reliably filled with blasting material are applied and can therefore also be cleaned properly.

In order to be able to clean not only surfaces lying next to the outlet end of the beam pipe of the beam probe, but also surfaces in front of the beam probe, it is provided that an angle between the impact surface and the longitudinal axis of the beam pipe is between 50 ° and 20 °, preferably between 40 ° and 30 °, in particular about 35 °.

The special angle setting of the baffle surface relative to the longitudinal axis of the jet pipe, i.e. the direction of transport of the blasting material through the jet pipe, enables that the stream of blasting material has both a radial component and an axial component, so that surfaces lying next to as well as in front of the tip of the blasting probe can be exposed to granular blasting material.

In order to ensure that the blasting material does not hit the edges of the outlet opening, it is more advantageous for the impact surface to be concave.

In an advantageous development of the invention, it is provided that the outlet opening is formed by a long pipe extending in the longitudinal direction of the jet pipe, the length of the baffle surface being approximately one third to four fifths of the length of the long hole when viewed in the longitudinal direction of the jet pipe.

By using an elongated hole as an outlet opening, a jet of blasting material which is divergent in particular in the axial direction of the blasting probe can be obtained, which blasting material can sweep over correspondingly wide strips on the walls of the cavity to be cleaned. This further simplifies the handling of the blasting probe for cleaning cavities.

According to the invention, the jet nozzle has several, preferably three, radial outlet openings which are evenly distributed in the circumferential direction of the jet pipe. By using several outlet openings that are evenly distributed around the circumference, a cleaning stream of blasting material is obtained, which can be guided through a cylindrical cavity like the inlet channel of a valve in internal combustion engines, essentially similar to a bottle brush. For example, if three circumferentially evenly distributed outlet openings of the jet nozzle are provided, the jet probe only needs to be rotated a little more than 120 ° around its longitudinal axis in order to apply blasting material to 360 ° of the surrounding walls.

Furthermore, the jet nozzle according to the invention has a nozzle body which has a bore extending in the longitudinal direction of the jet pipe which forms a blasting material channel which opens into the radial outlet openings and whose end in the direction of the jet is formed by the baffles, which form a roof-shaped or pyramid-shaped deflector form.

By designing the jet nozzle with a nozzle body in whose bore the front end of the jet pipe of the jet probe is inserted and which is welded, in particular spot-welded, to the jet pipe, the manufacture of the jet probe according to the invention can be simplified. In particular, this makes it possible to produce beam probes with different lengths in a simple manner. By inserting the jet pipe into the bore of the nozzle body it is also achieved that the blasting material channel in the nozzle body has a larger diameter than the blasting material flow emerging from the blasting tube, so that the effect of the blasting material flow on the inner walls of the bore in the nozzle body is reduced, thereby increasing the service life of the nozzle body is increased significantly.

In order to further increase the service life of the beam probe, that is to say its durability, in another embodiment of the invention it is provided that the nozzle body, in particular the deflecting body, is hardened.

According to claim 8, the blasting probe according to the invention is used with a device for cleaning cavities, which has a blasting material supply line which can be connected to the rear end of the blasting probe, the input end of which is connected to a device which is connected to a blasting material source and which is connected to a compressed gas line a compressed gas source can be connected in order to mix granular blasting material with a compressed gas. Such a device for cleaning cavities can be conveniently used in the workshop, since compressed air is usually available there as compressed gas for a variety of applications, which can then be used together with cleaning powder as granular blasting material to remove cavities, especially narrow coked cavities in internal combustion engines Removal to clean.

• Figur 1 ein vereinfachtes schematisches Blockbild einer Vorrichtung zur Reinigung von Hohlräumen mit einer erfindungsgemäßen Strahlsonde;
• Figur 2 eine vereinfachte schematische Schnittdarstellung eines zu reinigenden Hohlraums in einem Verbrennungsmotor während eines Reinigungsvorgangs mittels einer Strahlsonde;
• Figur 3 eine Draufsicht auf eine Strahlsonde;
• Figur 4 einen Schnitt durch das vordere Ende der in Figur 3 dargestellten Strahlsonde;
• Figur 5 eine Strahlsonde gemäß einem bevorzugten Ausführungsbeispiel der Erfindung;
• Figur 6 einen Schnitt im Wesentlichen nach Linie VI-VI in Figur 5; und
• Figur 7A bis 7C vereinfachte Darstellungen der in den Figuren 3 bis 6 gezeigten Strahlsonden zur Veranschaulichung der aus den verschiedenen Strahldüsen austretenden Strahlgutströme.

The invention is explained in more detail below using the drawing, for example. Show it:

• Figure 1 a simplified schematic block diagram of a device for cleaning cavities with a beam probe according to the invention;
• Figure 2 a simplified schematic sectional illustration of a cavity to be cleaned in an internal combustion engine during a cleaning process by means of a beam probe;
• Figure 3 a plan view of a beam probe;
• Figure 4 a section through the front end of the in Figure 3 beam probe shown;
• Figure 5 a beam probe according to a preferred embodiment of the invention;
• Figure 6 a section essentially along line VI-VI in Figure 5 ; and
• Figures 7A to 7C simplified representations of the Figures 3 to 6 blasting probes shown to illustrate the streams of blasting material emerging from the various blasting nozzles.

In the various figures of the drawing, components that correspond to one another are provided with the same reference symbols.

Figure 1 shows a device for cleaning cavities with a blasting probe 10, which is connected at its rear end to a blasting material supply line 11, the input end of which is connected to a mixing device 12, in the blasting material with compressed gas, z. B. compressed air is mixed so that the blasting probe 10 can be supplied with a stream of blasting material via the blasting material supply line 11. For this purpose, the mixing device 12 is on the one hand connected via a line 14 to a blasting material container 15 'serving as a blasting material source 15 and on the other hand can be connected via a pressurized gas line 16 to a pressurized gas source not shown in detail. The compressed gas line 16 is provided with a connection coupling 17 which can be connected, for example, to the compressed air system of a workshop.

To mix the granular blasting material with compressed air as the compressed gas, the blasting material, for. B. sucked in a cleaning powder in the mixing device 12 by the compressed air flowing through this, for example in the manner of a siphon or a water jet pump and mixed with this, so that the compressed air together with the granular blasting material which it transports are fed to the blasting probe 10 as a blasting material stream 24.

An example of a cavity to be cleaned is in Figure 2 an intake port 18 of an intake valve 19 in a cylinder head 20 is shown. The inlet valve 19 guided by means of a valve guide 21 in the cylinder head 20 is used to close and open an outlet opening 22 of the inlet channel 18, which at the same time forms an inlet opening of a cylinder space (not shown) in the cylinder block 23. In the area of the outlet opening 22 and the inlet valve 19, the inlet channel 18 and the inlet valve 19 tend to coke, so that these inlet channels 18 have to be cleaned from time to time depending on the type of operation of the internal combustion engine.

For this purpose, a cleaning powder is blasted as a granular blasting material against the walls of the inlet channel 18 and the exposed surfaces of the inlet valve 19 that in Figure 2 Soiling, not shown in detail, is removed from the surfaces to be cleaned by the cleaning powder in the manner of sandblasting. The cleaning powder is introduced into the interior of the inlet channel 18 as a jet stream 24 through a jet channel 25 of the jet probe 10 and directed against the inner walls of the cavity by a jet nozzle 27 provided at the front end of the jet probe 10. If the blasting probe 10 is rotated about its longitudinal axis, the blasting material flow exiting with a radial component is pivoted accordingly and the cleaning powder of the blasting material flow 24 can apply and clean all the walls of the cavity to be cleaned, i.e. the inner walls of the inlet channel and the surfaces of the inlet valve 19.

The structure of the in Figure 2 schematically illustrated beam probe 10 is based on the Figures 3 and 4 explained in more detail.

In the Figure 3 The beam probe 10 shown has a beam tube 28, at the front of which in Figure 3 right end the jet nozzle 27 is provided. The jet nozzle 27 comprises a radial outlet opening 29, which is preferably designed as an elongated hole, and a baffle surface 30, which is arranged obliquely to the longitudinal axis 31 of the jet pipe, as particularly well in FIG Figure 4 can be seen. The angle a which the impact surface encloses with the longitudinal axis 31 of the jet pipe is in the illustrated embodiment 35 °. However, it can also be larger or smaller, depending on the direction in which the stream of blasting material is to be directed, which in turn depends on the geometry of the cavities to be cleaned. Depending on whether the radial component of the blasting material flow 24 emerging from the blasting nozzle 27 or its axial component is to predominate, the angle α is selected to be larger or smaller. The angle α is preferably in the range between 50 ° and 20 °, in particular in the range between 40 ° and 30 °. In a jet probe tested in the laboratory, particularly good cleaning results were achieved in inlet channels of inlet valves in internal combustion engines at an angle α between the impact surface 30 and the longitudinal axis 31 of the jet pipe 28 of 35 °.

To use the beam probe 10 with the in Figure 3 To be able to connect the blasting material feed line, a cutting ring 32 is provided in the area of the end of the blasting tube 28 facing away from the blasting nozzle 27, which, together with a union nut 33, serves to screw the blasting material feed line securely to the blasting probe 10 in the connection area.

So that the user of the blasting probe 10 knows after inserting the blasting nozzle 27 into the cavity to be cleaned in which direction the blasting material flow 24 emerges from the blasting nozzle 27, there is a side diametrically opposite to the outlet opening 29 of the blasting nozzle 27 in the rear area of the blasting tube 28 Disk 34 attached, in particular welded on.

At the in Figure 5 beam probe 10 according to the invention shown is on the front, in Figure 5 A jet nozzle 27 is placed on the right end of the jet pipe 28, which has a nozzle body 26 which has a bore 35 which extends in the longitudinal direction of the jet pipe 28 and which forms a jet material channel 36 which opens into radial outlet openings 29.

The jet pipe 28 is inserted into the bore 35 of the nozzle body 26 and is preferably welded to the nozzle body 26, in particular spot-welded. Since the diameter of the blasting material channel 35 is greater than the diameter of the blasting material channel 25 in the jet pipe 28, practically no blasting material hits the inner circumferential surface of the blasting material channel 35 in the nozzle body 26, whereby the wear is reduced.

As in Figure 6 can be seen, the nozzle body 26 has three circumferentially evenly distributed outlet openings 29, each of which is assigned its own baffle surface 30. The three baffle surfaces 30 thus form a conical or pyramidal deflecting body 37 which is supported by webs 38 between the outlet openings 29. The baffle surfaces 30 are designed in such a way that no blasting material hits the webs 38. For example, the impact surfaces 30 can be concave for this purpose.

Instead of three circumferentially uniformly distributed outlet openings 29 with corresponding baffle surfaces 30 which form a pyramidal deflecting body 37, two or more outlet openings can also be provided circumferentially distributed. If, for example, two outlet openings located diametrically opposite one another are provided, the deflecting body formed by their associated baffle surfaces is roof-shaped. If more than three openings, i.e. four or five circumferentially evenly distributed outlet openings with corresponding baffles, are provided, the conical deflecting body 37 represents a square or pentagonal pyramid.

In order to increase the wear resistance of the deflecting body 37, it is preferably hardened.

The outlet openings 29 in the jet nozzle 27 according to FIG Figure 5 are designed as elongated holes. How especially good in the Figures 3, 4 and 5 As can be seen, the length of the baffle surfaces 30 in the longitudinal direction of the jet pipe 28, i.e. the projection of the baffle surfaces 30 onto the longitudinal axis 31 of the jet pipe 28, is shorter than the length of the elongated hole forming the outlet opening 29. In particular, the length of the projection of the impact surface 30 onto the corresponding longitudinal axis 31 of the jet pipe 28 is approximately one third to four fifths of the length of the elongated hole forming the outlet opening 29.

Figures 7A to 7C illustrate schematically the deflection of the stream of blasting material 24 at the baffle surface or surfaces 30 of the blasting nozzles 27. As in FIG Figure 7A It can be seen that the divergent flow of blasting material emerging from the outlet opening of the nozzle 27 24 'has both radial and axial components, so that by rotating the blasting probe about its longitudinal axis, the exiting blasting material flow 24' can be pivoted through 360 °.

As in Figures 7B and 7C can be seen, provides the embodiment of the invention Figure 5 three streams of blasting material 24 ″ emerging from the corresponding exit openings 29 of the blasting nozzle 27, which are arranged circumferentially offset by 120 ° in accordance with the arrangement of the exit openings Rotate so that the streams of blasting material 24 ″ must each be pivoted by 120 ° in order to be able to act on the full circle with blasting material, that is to say with corresponding granular cleaning agents.

The blasting probe 10 according to the invention makes it possible to apply cleaning powder as blasting material to all the walls of a cavity to be cleaned by simply shifting and rotating about its longitudinal axis, and thus to clean them.

Claims (8)

1. Blasting probe (10) for introducing a granular blasting material into a cavity, in particular into a narrow, coked cavity such as an inlet channel (18) of a valve (19) of an internal combustion engine, in particular for cleaning said cavity, the probe comprising

   - a blast tube (28), a rear end of which can be connected to a blasting material feed line (11) and

   - a blast nozzle (27) at the front end of the blast tube (28), which blast nozzle has a plurality of, preferably three, outlet openings (29) for the blasting material which are radial in relation to the longitudinal axis (31) of the blast tube (28), are evenly distributed in the circumferential direction of the blast tube (28) and are each associated with an impact surface (30) arranged obliquely with respect to the longitudinal axis (31) of the blast tube (28),

   characterized in that the blast nozzle (27) has a nozzle body (26) having a bore (35), which bore extends in the longitudinal direction of the blast tube (28) and forms a blasting material channel (36), which channel opens into the radial outlet openings (29) and the end of which channel in the blasting direction is formed by the impact surfaces (30) which form a roof-shaped or pyramid-shaped deflecting body (37).
2. Blasting probe (10) according to claim 1, characterized in that an angle α between the impact surface (30) and the longitudinal axis (31) of the blast tube (28) is between 50° and 20°, preferably between 40° and 30°, in particular approximately 35°.
3. Blasting probe (10) according to claim 1 or 2, characterized in that the impact surface (30) is curved in a concave manner.
4. Blasting probe (10) according to any of claims 1, 2 or 3, characterized in that the outlet opening (29) is formed by an elongate hole extending in the longitudinal direction of the blast tube (28).
5. Blasting probe (10) according to claim 4, characterized in that the length of the impact surface (30), viewed in the longitudinal direction of the blast tube (28), is approximately one third to four fifths of the length of the elongate hole.
6. Blasting probe (10) according to any of the preceding claims, characterized in that the nozzle body (26), in particular the deflecting body (37), is hardened.
7. Blasting probe (10) according to any of the preceding claims, characterized in that the front end of the blast tube (28) is inserted into the bore forming the blasting material channel (36), and in that the nozzle body (26) is welded, in particular is spot-welded, to the blast tube (28).
8. Device for cleaning cavities, in particular narrow, coked cavities such as inlet channels (18) of valves (19) of internal combustion engines, the device comprising

   - a blasting probe (10) according to any of the preceding claims and

   - a blasting material feed line (11) connected to the rear end of the blasting probe (10), the inlet end of which feed line is connected to a device (12), which device is connected to a blasting material source (15) for mixing granular blasting material with a compressed gas and can be connected via a compressed gas line (16) to a compressed gas source.

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