BLASTING PROBE FOR INTRODUCING A GRANULAR BLASTING MATERIAL INTO A CAVITY

Abstract

The invention relates to a blasting probe for introducing a granular blasting material into a cavity, in particular into a narrow coked cavity such as an inlet channel of a valve of an internal combustion engine, in particular for cleaning said cavity, comprising a blasting pipe (connectable, at a rear end thereof, to a blasting material feeding line, and a blasting nozzle at the front end of the blasting pipe, said blasting nozzle having at least one outlet opening for the blasting material which is radial with respect to the longitudinal axis of the blasting pipe and which is associated with a deflector surface arranged obliquely with respect to the longitudinal axis of the blasting pipe.

Claims

1. A blasting probe for introducing a granular blasting material into a cavity, in particular into a narrow coked cavity such as an inlet channel of a valve of an internal combustion engine, in particular for cleaning said cavity, comprising a blasting pipe connectable, at a rear end thereof, to a blasting material feeding line, and a blasting nozzle at the front end of said blasting pipe, said blasting nozzle having at least one outlet opening for the blasting material which is radial with respect to the longitudinal axis of said blasting pipe and which is associated with a deflector surface arranged obliquely with respect to the longitudinal axis of said blasting pipe.

2. The blasting probe according to claim 1, wherein an angle between said deflector surface and the longitudinal axis of said blasting pipe is between 50 and 20, preferably between 40 and 30, in particular about 35.

3. The blasting probe according to claim 1, wherein said deflector surface is concave.

4. The blasting probe according to claim 1, wherein said outlet opening is formed by an elongated hole extending in the longitudinal direction of said blasting pipe.

5. The blasting probe according to claim 4, wherein the length of said deflector surface, viewed in the longitudinal direction of said blasting pipe, is about one-third to four-fifths of the length of said elongated hole.

6. The blasting probe according to claim 1, wherein said blasting nozzle has a plurality of, preferably three, radial outlet openings distributed uniformly in the circumferential direction of said blasting pipe.

7. The blasting probe according to claim 6, wherein said blasting nozzle comprises a nozzle body having a bore, said bore extending in the longitudinal direction of said blasting pipe and forming a blasting material channel which opens into the radial outlet openings and the end of which in the blasting direction is formed by the deflector surfaces forming a roof-shaped or pyramid-shaped deflecting body.

8. The blasting probe according to claim 7, wherein said nozzle body, in particular said deflecting body, is hardened.

9. The blasting probe according to claim 7, wherein the front end of said blasting pipe is inserted into the bore forming said blasting material channel, and that said nozzle body is welded, in particular spot-welded, to said blasting pipe.

10. A device for cleaning cavities, in particular narrow coked cavities such as inlet channels of valves of internal combustion engines, said device comprising a blasting probe according to one of the preceding claims, and a blasting material feeding line connected to the rear end of said blasting probe, the input end of said blasting material feeding line being connected to a device which is connected to a blasting material source for mixing granular blasting material with a compressed gas and which is connectable to a compressed-gas source via a compressed-gas line.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Exemplarily, the invention will be explained in more detail below with reference to the drawing. Show it:

[0022] FIG. 1 is a simplified schematic block diagram of a device for cleaning cavities with a blasting probe according to the invention;

[0023] FIG. 2 is a simplified schematic sectional view of a cavity to be cleaned in an internal combustion engine during a cleaning process by means of a blasting probe according to the invention;

[0024] FIG. 3 is a plan view of a blasting probe according to the invention according to a first embodiment of the invention;

[0025] FIG. 4 shows a sectional view through the front end of the blasting probe according to the invention shown in FIG. 3;

[0026] FIG. 5 shows a blasting probe according to a preferred embodiment of the invention;

[0027] FIG. 6 is a sectional view substantially taken along line VI-VI in FIG. 5; and

[0028] FIGS. 7A to 7C show simplified representations of the blasting probe according to the invention for illustrating the blasting material streams emerging from the various blasting nozzles.

[0029] Throughout the various figures of the drawing, corresponding components are provided with the same reference numerals.

DETAILED DESCRIPTION

[0030] FIG. 1 shows a device for cleaning cavities with a blasting probe 10 connected, at the rear end thereof, to a blasting material feeding line 11, input end of which is connected to a mixing device 12, in which blasting material is mixed with compressed gas, e.g., compressed air, so that the blasting probe 10 can be supplied with a blasting material stream via the blasting material feeding line 11. For this purpose, the mixing device 12 is connected, on the one hand, via a line 14 to a blasting material container 15 serving as the blasting material source 15 and, on the other hand, connected via a compressed gas line 16 to a compressed gas source (not shown in detail). The compressed gas line 16 is provided with a connector coupling 17 which can be connected, for example, to the compressed air system of a workshop.

[0031] In order to mix the granular blasting material with compressed air as a compressed gas, in the mixing device 12, the blasting material, e.g., a cleaning powder, sucked in by the compressed air flowing through the mixing device 12, for example in the manner of a siphon or a water jet pump, and mixed therewith, so that the compressed air, along with the granular blasting material it transports, can be supplied to the blast probe 10 as the blasting material stream 24.

[0032] As an example of a cavity to be cleaned, FIG. 2 shows an inlet channel 18 of an inlet valve 19 in a cylinder head 20. The inlet valve 19, which is guided in the cylinder head 20 by means of a valve guide 21, serves to close and open an outlet opening 22 of the inlet channel 18 which simultaneously 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 14 are prone to coking, 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.

[0033] For this purpose, a cleaning powder as a granular blasting material is blasted against the walls of the inlet channel 18 and the exposed surfaces of the inlet valve 19 such contaminants (not shown in detail in FIG. 2) are removed from the surfaces to be cleaned by the cleaning powder similar to sand blasting. The cleaning powder is introduced as the blasting material stream 24 via a blasting material channel 25 of the blasting probe 10 into the interior of the inlet channel 18 and directed against the inner walls of the cavity by a blasting nozzle 27 provided at the front end of the blasting probe 10. When the blasting probe 10 is rotated about its longitudinal axis, the blasting material stream exiting with a radial component is pivoted correspondingly and the cleaning powder of the blasting stream 24 may act on 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.

[0034] The structure of the blasting probe 10 according to the invention will be explained in more detail with reference to FIGS. 3 and 4.

[0035] The blasting probe 10 shown in FIG. 3 comprises a blasting pipe 28, at the front right end of which in FIG. 3 the blasting nozzle 27 is provided. Here, the blasting nozzle 27 comprises a radial outlet opening 29, which is preferably formed as an elongated hole, and a deflector surface 30 arranged obliquely with respect to the longitudinal axis 31 of the blasting pipe, as is particularly apparent in FIG. 4. The angle between the deflector surface and the longitudinal axis 31 of the blasting pipe is 35 in the illustrated embodiment. However, it can also be larger or smaller depending on the direction in which the blasting material stream is to be directed, which in turn is dependent on the geometry of the cavities to be cleaned. Depending on whether the radial component or the axial component of the blasting material stream 24 emerging from the blasting nozzle 27 should predominate, the angle is selected to be larger or smaller. Preferably, the angle is in the range between 50 and 20, in particular in the range between 40 and 30. In a blasting probe tested in the laboratory, particularly good cleaning results were achieved in intake channels of intake valves in internal combustion engines with an angle of 35 between the deflector surface 30 and the longitudinal axis 31 of the blasting pipe 28.

[0036] In order to connect the blasting probe 10 with the blasting material feeding line (not shown in FIG. 3), a cutting ring 32 is provided in the region of the end facing away from the blasting nozzle 27 of the blasting pipe 28, the cutting ring 32 along with a cap nut 33 serving to safely screw the blasting material feeding line to the blasting probe 10 in the connection region.

[0037] In the rear region of the blasting pipe 28 on the side diametrically opposite to the outlet opening 29 of the blasting nozzle 27, a disc 34 is attached, in particular welded thereto, so that, after the introduction of the blasting nozzle 27 into the cavity to be cleaned, the user of the blasting probe 10 knows, in which direction the blasting material stream 24 emerges from the blasting nozzle 27.

[0038] In the blasting probe 10 according to the invention shown in FIG. 5, a blasting nozzle 27 is mounted on the front right end of the blasting pipe 28 in FIG. 5, the blasting nozzle comprising a nozzle body 26 having a bore 35 extending in the longitudinal direction of the blasting pipe 28, which forms a blasting material channel 36 opening into radial outlet openings 29.

[0039] The blasting pipe 28 is inserted into the bore 35 of the nozzle body 26 and preferably welded, in particular spot-welded, to the nozzle body 26. Since the diameter of the blasting material channel 35 is greater than the diameter of the blasting material channel 25 in the blasting pipe 28, virtually no blasting material hits the inner peripheral surface of the blasting material channel 35 in the nozzle body 26, whereby the wear is reduced.

[0040] As can be seen in FIG. 6, the nozzle body 26 has three outlet openings 29 distributed uniformly in circumferential direction, each having its own deflector surface 30. Thus, the three deflector surfaces 30 form a conical or pyramid-shaped deflection body 37, which is supported by bars 38 between the outlet openings 29. The deflector surfaces 30 are configured such that no blasting material hits the bars 38. For example, the deflector surfaces 30 may be concave thereto.

[0041] Instead of three outlet openings 29 distributed uniformly in circumferential direction with corresponding deflector surfaces 30 forming a pyramid-shaped deflecting body 37, two or more outlet openings may be distributed in circumferential direction. When, for example, two diametrically opposite outlet openings are provided, the deflection body formed by the associated deflector surfaces is roof-shaped. When more than three, i.e., four or five, outlet openings distributed uniformly in circumferential direction with corresponding deflector surfaces are provided, the conical deflection body 37 is a quadrangular or pentagonal pyramid.

[0042] In order to increase the wear resistance of the deflection body 37, it is preferably hardened.

[0043] The outlet openings 29 in the blasting nozzle 27 according to FIG. 5 are also configured as elongated holes. As is apparent in FIGS. 3, 4 and 5, the length of the deflector surfaces 30 in the longitudinal direction of the blasting pipe 28, that is, the projection of the deflector surfaces 30 onto the longitudinal axis 31 of the blasting 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 deflector surfaces 30 onto the corresponding longitudinal axis 31 of the blasting pipe 28 is about one third to four fifths of the length of the outlet opening 29 forming the elongated hole.

[0044] FIGS. 7A to 7C schematically illustrate the deflection of the blasting material stream 24 at the deflector surface(s) 30 of the blasting nozzles 27. As can be seen in FIG. 7A, the divergent blasting material stream 24 emerging from the outlet opening of the nozzle 27 has both radial and axial components such that the emerging blasting material stream 24 can be pivoted by 360 by rotation of the blasting probe about its longitudinal axis.

[0045] As is apparent in FIGS. 7B and 7C, the embodiment of the invention according to FIG. 5 provides three blasting material streams 24 which emerge from the corresponding outlet openings 29 of the blasting nozzle 27 and are arranged offset from each other by 120 in circumferential direction in accordance with the arrangement of the outlet openings. In order to be able to cover 360, it is only necessary to rotate the blasting probe 10 by 120, so that the blasting material streams 24 must be pivoted by 120 in order to apply the blasting material, i.e., appropriate granular cleaning agents, to the full circle.

[0046] By simple displacement and rotation about its longitudinal axis, the blasting probe 10 according to the invention allows the cleaning powder as a blasting material to be applied to all the walls of a cavity to be cleaned, thereby cleaning the cavity.