EP0655963B1 - Mobile centrifugal blasting machine - Google Patents

Abstract

The proposal is for a mobile centrifugal blasting machine which can be moved in a working direction over areas (4) to be sprayed. It has two spinners (7, 8) arranged side-by-side transversely to the working direction which, during operation, generate a jet of particles (43, 44) directed towards an area (4) to be sprayed. This produces in the impact region (33) of the area (4) a central jet region (49) sprayed by the peripheral jet regions (47, 47') of both particle jets (43, 44) directed towards each other, thus giving a very uniform spray pattern over the area (4).

Description

Mobile centrifugal blasting machine that can be moved in one working direction over surfaces to be blasted, whereby steel particles accelerated by rotating centrifugal wheels are thrown in the direction of the surface to be blasted and hit them in an impact zone, with two centrifugal wheels arranged next to one another transversely to the working direction, each of which has one surface to be blasted during operation generate directed particle beam.

A centrifugal jet machine of this type can be found, for example, in DE-OS 25 06 740 or DE-OS 26 52 416. It has two centrifugal wheels that can be driven by a motor to make a rotational movement, the axis of rotation of which runs in each case in a plane that is spanned by the working direction and the height direction of the machine. Jet particles, in particular small spherical bodies, supplied from a storage device are accelerated by the rotating centrifugal wheels and are thrown in the form of two adjacent particle jets against the surface to be blasted located in the area of the underside of the machine. The required material removal takes place there in the area of the impact zone. The materials that can be blasted can in particular be concrete, coatings, screeds or steel plates.

In comparison to a centrifugal jet machine with only one centrifugal wheel, as described in DE 27 08 528 C2 the previously mentioned centrifugal jet machines have a larger working width. However, the beam pattern generated is extremely uneven. Because of the inevitable scattering of the jet particles, a central zone with a relatively low radiation intensity is regularly established, which is flanked on both sides by zones with a higher radiation intensity, so-called hot spots. This is particularly disadvantageous if the blasted surfaces remain as visible surfaces and may later only be sealed colorless. The appearance is particularly pronounced with relatively soft material of the surfaces to be blasted.

In order to avoid a non-uniform radiation result, it has already been proposed in connection with a stationary centrifugal jet system according to US Pat. No. 3,832,809 to generate an overlapping beam pattern. However, since the centrifugal wheels are to be arranged offset in the feed direction of the workpiece to be blasted, this results in a length that is unfavorable for mobile centrifugal blasting machines and undesirable restrictions in the field of application.

FR-A-2 443 902 discloses a machine for cleaning surfaces in which the width of the particle beam can be adjusted by means of side baffle plates.

It is the object of the present invention to create a mobile centrifugal blasting machine of the type mentioned at the outset, with which a uniform spray pattern can be generated over a large working width with a high work output.

This object is achieved in that the centrifugal jet machine is designed in such a way that the two adjacent particle beams with their mutually facing jet edge regions mesh with one another at the latest when they reach the impact zone and overlap in such a way that they complement one another to form an overall jet in the impact zone produces a central radiation region which is irradiated jointly by the two beam edge regions, in which the radiation intensity corresponds at least substantially to that which is produced by a respective main beam region of the two particle beams which adjoins the associated beam edge region.

In this way, in the impact zone across a very large width across the working direction, a very uniform spray pattern is created without pronounced hot spots. If a working path is covered with the centrifugal blasting machine, the result is a very uniform radiation strip, which is essentially composed of three strip-like radiation areas lying side by side and imperceptibly merging into one another. In the central radiation area, processing takes place through the mutually facing beam edge areas of both particle beams. This superimposition results in an increased resulting radiation intensity which at least essentially corresponds to that which is generated by a respective adjacent main beam region of the two particle beams. As a result of the resulting uniform spray pattern, the working area of the centrifugal jet machine can be used well. As a result, a considerably larger area of higher quality can be blasted per unit of time than is possible in the prior art. The efficiency is considerably higher.

Advantageous developments of the invention are listed in the subclaims.

Both centrifugal wheels are preferably of identical mirror image design and are expediently operated at the same speed. Each centrifugal wheel can be assigned its own drive motor. It would also be conceivable to use a central drive motor that drives both centrifugal wheels with the interposition of a suitable gear.

In order to obtain a uniform spray pattern in the entire impact zone up to the lateral edges of the impact zone, means are expediently provided which prevent particles of the particle beams from hitting the surface to be blasted laterally outside the main beam regions.

Figur 1

ein erstes Ausführungsbeispiel der erfindungsgemäßen Schleuderstrahlmaschine in Seitenansicht gemäß Pfeil II aus Figur 2, teilweise aufgebrochen und stark schematisiert,

Figur 2

die bei der Schleuderstrahlanlage gemäß Figur 1 vorgesehene Schleuderradanordnung in vergrößerter Darstellung, mit einer mit der Arbeitsrichtung zusammenfallenden Blickrichtung gemäß Pfeil I, wobei die Schleuderräder vereinfacht als Kreise dargestellt sind, wiederum stark schematisiert, und

Figur 3

in einer der Figur 2 entsprechenden Darstellungsweise eine weitere bei der Schleuderstrahlmaschine gemäß Figur 1 vorteilhaft zu verwirklichende Schleuderradanordnung.

The invention is explained in more detail below with reference to the accompanying drawing. In this show:

Figure 1

2 shows a first exemplary embodiment of the centrifugal jet machine according to the invention in side view according to arrow II from FIG. 2, partially broken open and highly schematic,

Figure 2

1 in an enlarged representation, with a direction of view coinciding with the working direction according to arrow I, the centrifugal wheels being shown in simplified form as circles, again highly schematic, and

Figure 3

in a representation corresponding to FIG. 2, a further centrifugal wheel arrangement to be advantageously implemented in the centrifugal jet machine according to FIG. 1.

Unless otherwise specified, the following description relates to both of the embodiment variants shown in FIGS. 2 and 3.

The general structure of the exemplary mobile centrifugal jet machine is evident from FIG. It has a structure, generally designated 1, which rests on a chassis 2. With the chassis 2 it is placed on a surface 4 to be blasted, which in the present case is a horizontally running floor surface of a useful floor in the industrial or private sector. This floor is made of concrete, which of course can also be a different material or a mixed material. The surface 4 to be blasted does not necessarily have to be a floor surface, it can also be the surface of any other body, for example that of a steel plate. However, the preferred machining is carried out on at least substantially horizontally oriented surfaces, without the invention being restricted to such an application.

In operation, the centrifugal jet machine is moved over the surface 4 to be blasted by an operator. A handle 3 can be provided for guidance that may be necessary. The direction of movement of the centrifugal jet machine during operation is referred to as the working direction, it is indicated by the arrow 5. The centrifugal jet machine will be moved regularly, covering working paths that adjoin one another laterally.

With reference also to Figures 2 and 3, the structure 1 has a housing 6 which receives two centrifugal wheels 7, 8. Because of the side view, only one (7) of these centrifugal wheels can be seen in FIG. The construction of a centrifugal wheel as such is known to the person skilled in the art, so that detailed explanations are unnecessary at this point.

Each centrifugal wheel 7, 8 is rotatable about a central longitudinal axis 12, 13. The corresponding rotary drive is provided, for example, by two drive motors, only one of which is shown at 14 in FIG. 1 and which are each assigned to one of the centrifugal wheels 7, 8. The drive motors 14 are, for example, attached to the housing 6 and flanged directly to the associated centrifugal wheel 7, 8 without complex intermediate gears.

It would be entirely possible to provide a common drive motor for both centrifugal wheels 7, 8, which is then expediently connected to the centrifugal wheels 7, 8 via an interposed belt drive or another transmission (not shown). In this way, identical rotational speeds of the two centrifugal wheels 7, 8 can be realized in a particularly simple manner.

At the top of the housing 6 there is a receptacle 15 for jet particles 16. The latter are particles in bulk form, in particular spherical in shape, which is why the present machine could also be referred to as a shot peening machine. The receptacle 15 is connected to the housing 6 via two feed channels 17, 18, one of the feed channels 17, 18 each opening into the housing 6 in the region of one of the centrifugal wheels 7, 8 (indicated by dash-dotted lines in FIGS. 2 and 3). In this way, the jet particles 16 are simultaneously fed to two centrifugal wheels 7, 8 due to gravity.

The centrifugal wheels 7, 8 rotating during operation hurl the blasting particles 16 fed to them in accordance with arrows 19 (FIG. 1) in the direction of the surface 4 to be blasted, which is located in the region of the underside of the centrifugal blasting machine. There, the centrifugal jet machine has a working opening 23 which is bounded by a frame and which is open to the surface 4 to be blasted. The path of the jet particles 16 to the working opening 23 is guided by housing walls 24 which connect to the blast wheel housing 6 and define a jet channel 25.

After the centrifugal force-thrown jet particles 16 have impacted through the working opening 23 through the surface 4, they rebound from this again according to arrows 26 and return via a return channel 27 also communicating with the opening 23 according to arrow 28 back into the receiving container 15. The return can be based solely on the rebound energy, but additional mechanical feedback support, for example, is also possible. At the moment of impact on the surface 4, the jet particles 16 carry out a material removal thereon. The particles removed in the process likewise enter the return channel 27 and are separated from the jet particles 16 before reaching the receiving container 15. Suitable means are provided for this, For example, a blower 32, which is only schematically indicated in FIG. 1 and which acts on the return duct 27 before reaching the receiving container 15 with a transverse air stream which removes the lighter removed particles. The blasting particles 16 returning to the receiving container 15 are then fed again to the centrifugal wheels 7, 8, so that the cycle can start again.

The area of the surface 4 which is currently traversed by the working opening 23 forms an impact zone 33 for the blasting particles 16. Its width corresponds essentially to that of the blasting channel 25 provided jointly for the two blasting wheels 7, 8. The two blasting wheels 7, 8 are transverse to the working direction 5 arranged side by side (transverse direction 29), where they are expediently at the same height, as can be seen from Figures 2 and 3. The arrangement is preferably such that the two centrifugal wheels 7, 8 come to lie symmetrically on both sides of a longitudinal center plane 35 oriented both in the machine height direction 34 and in the working direction 5, as is realized in both exemplary embodiments. Here, the two centrifugal wheels 7, 8 are arranged horizontally at right angles to the working direction with a relatively small distance laterally next to each other, so that their peripheral sides face each other.

It has proven to be advantageous to arrange the centrifugal wheels 7, 8 in such a way that their axes of rotation 12, 13 are contained in axis planes 36, 37 arranged parallel to one another, which run parallel to the longitudinal central plane 35 defined above, whereby they are inclined with respect to the horizontal . The wheel planes running at right angles to the axes of rotation 12, 13 are thus arranged at a preferably acute angle to the surface 4 to be blasted, so that the jet particles 16 according to arrows 19 meet the impact zone 33 obliquely and an optimal rebound effect occurs in the adjoining return duct 27.

As can be seen from Figures 2 and 3, the two centrifugal wheels 7, 8 preferably rotate in opposite directions during operation. If you look at the centrifugal wheel arrangement in working direction 5, in the case of the embodiment variant in FIG. 2, the left centrifugal wheel 7 rotates clockwise according to arrow 38 and the right centrifugal wheel 8 rotates counterclockwise according to arrow 39. In this way, they each have during rotation currently facing inner wheel sections 40, 40 'have a movement component directed downwards towards the impact zone 33. In the variant according to FIG. 3, the direction of rotation of a respective centrifugal wheel 7, 8 is just opposite, so that the outer wheel sections 41, 41 ', which are currently facing away from each other in the transverse direction 29 during rotation, have a movement component directed downwards towards the impact zone 33.

During operation, each centrifugal wheel 7, 8 generates its own particle beam 43, 44 directed downwards in the direction of the underside of the machine. For better differentiation, the left-hand particle beam 43 is indicated by dash-dotted lines and the right-hand particle beam 44 by dashed lines. The setting can expediently be made such that the main beam directions of the two particle beams 43, 44 indicated by the arrows 45, 46 in the direction of the impact zone 33 diverge slightly obliquely (FIG. 2) or converge slightly obliquely (FIG 3). A respective particle beam 43, 44 widens starting from the assigned centrifugal wheel 7, 8 and has its largest width measured transversely to the longitudinal center plane 35 in the area of the impact zone 33.

The two centrifugal wheels 7, 8, which are aligned with one another in the transverse direction 29, are otherwise designed and arranged such that the two resulting and adjacent particle beams 43, 44 overlap with their mutually facing beam edge regions 47, 47 'transversely to the longitudinal center plane 35. The overlapping beam area is indicated in FIGS. 2 and 3 at 48 and, when the viewing direction coincides with the working direction 5, has, for example, a shape similar to an isosceles triangle, the two sides of the same length being formed by the boundaries of the overlapping beam edge areas 47, 47 '. The distance s between the beginning of the overlap and the impact zone 33 depends in particular on the angle of propagation of the individual particle beams 43, 44 and on the setting of the main beam directions 45, 46. In the case of FIG. 2, the distance s is greater than in the case of FIG. 3, where the beam edge regions 47, 47 'only overlap or cross relatively late.

Overall, the impact zone 33 is thus divided transversely to the working direction 15 into three strip-like radiation areas 49, 50, 51 which merge directly into one another. The result is a central, central working area 49 in which the overlapping beam edge areas 47, 47 'collide together. This is flanked on both sides by external radiation areas 50, 51, which are caused by the remaining beam portion of a respective one of the two particle beams 43, 44. This remaining beam component is largely determined by a main beam region 52, 53 which immediately adjoins the assigned inner beam edge region 47, 47 'and which has a high beam intensity. The mutually adjacent inner beam edge areas 47, 47 ', on the other hand, each have a lower beam intensity, so that in the event of an impact without overlap, radiation areas would arise in which a smaller one Material removal has taken place. However, this is compensated for by the beam overlap, since the low beam intensities add up and result in a higher total beam intensity, which essentially corresponds to that of an adjacent main beam region 52, 53. In this way, a uniform beam pattern without so-called hot spots is established over a very large width of the impact zone 33.

In the case of the embodiment variant according to FIG. 2, in the immediate vicinity of the lateral edge areas of the impact zone 33, a narrow radiation area, which is not shown in FIG. 2 and has a somewhat reduced processing intensity, is generally to be tolerated. This is due to the fact that the outer beam edge regions 54, 54 'facing away from one another in the transverse direction 29 generally have a slightly reduced beam intensity compared to the main beam region 52, 53. This is of minor importance in individual cases, since the overall radiation width achieved, which has a uniform radiation result, is already very considerable. The embodiment variant of FIG. 3, however, is distinguished by a structure that deliberately avoids corresponding radiation areas of reduced intensity, so that the beam pattern set in the impact zone 33 does not weaken, or at least not significantly, towards the lateral edge areas. The result is a clear delimitation of the beam image generated on both sides, which facilitates the machining process carried out in paths, since radiation path can be placed on radiation path without having to make an overlap.

This is achieved in that in the beam path of the two outer beam edge areas 54, 54 'a housing-wall-mounted blanking device 55 is arranged, which practically hides the relevant beam edge area 54, 54' and thus prevents the beam edge areas 54, 54 'impact on the surface 4 to be blasted where they would strike with an unobstructed beam path. In FIG. 3, two edge zones 56 are indicated laterally adjacent to the impact zone 33, in which the beam edge regions 54, 54 'would impact if they could reach the surface 4 to be blasted directly and unhindered, as indicated by dots at 57. These edge zones would be characterized by a lower radiation intensity. By eliminating them, there remains a beam image which is composed of two outer radiation areas 50, 51 and a central radiation area 49, these three radiation areas being characterized by a practically identical radiation intensity and the entire beam area being sharply delimited on both sides.

The masking devices 55 are preferably formed by the lateral housing walls 24 and in particular by their wall end regions 58 which directly adjoin the working opening 23 and extend in the direction of the centrifugal wheels 7, 8. The lateral beam edge regions 54, 54 'collide with these wall end regions 58, before they reach the surface 4 to be blasted. So that the blasted blasted particles do not remain on the floor, but continue to participate in the blasting medium circuit, the blanking devices 55 are preferably designed in the form of reflection devices 59, which applies to the embodiment variant according to FIG. 3. The beam particles impinging on the masking devices 55 are thus reflected (indicated by arrows 60) and hit the outer radiation areas 50, 51, which are already irradiated by the main beam areas 52, 53. From there they rebound according to arrows 26 in order to be returned to the receptacle 15. Since the beam intensity of the outer beam edge areas 54, 54 'is reduced from the start and, furthermore, the above-mentioned reflection is added to attenuate the energy, the beam image in FIG the outer radiation areas 50, 51 not visibly impaired by the additional radiation.

In connection with the masking out of the outer jet edge regions 54, 54 ', the direction of rotation of the two centrifugal wheels 7, 8 provided in the embodiment variant according to FIG. 3 is advantageous. It causes the outer beam edge areas 54, 54 'to strike the wall end areas 58 relatively flat at a very small angle 61, so that little wear occurs.

The embodiment variant according to FIG. 2 can also be operated in connection with masking devices 55. For this purpose, only the setting on the centrifugal wheel side must be carried out in such a way that the main jet directions 45, 46 diverge more and the outer jet edge regions 54, 54 'also strike the lateral housing walls 24. However, somewhat increased wear would have to be expected since the impact angle - causing the other direction of rotation of the centrifugal wheels 7, 8 - would be greater than in the variant according to FIG. 3.

It goes without saying that the masking devices 55 can be formed by parts which protrude into the beam channel 25. For example, these can be baffle plates which are in particular exchangeably fastened to the housing wall 24.

It is therefore important that the two particle beams 43, 44 partially interlock or overlap on the facing beam sides, so that an essentially uniform beam intensity having an essentially uniform beam intensity arrives at the latest when the impact zone 33 is reached. The masking devices 55 which may be present enable additional beam image optimization in the outer edge regions of the impact zone, so that the result of the work is the entire width of the Impact zone produces a sharply defined beam pattern with uniform radiation.

Claims (10)

1. Mobile centrifugal blast cleaning machine movable across surfaces to be cleaned in one operating direction (5) while blasting particles accelerated by rotating impellers (7, 8) are thrown towards the surface (4) to be cleaned and hit it in an impact zone (33), with two impellers (7, 8) located next to each other at right angles to the operating direction (5) to produce a particle stream (43, 44) directed towards the surface (4) to be cleaned during operation, characterized in that the two adjacent particle streams (43, 44) merge laterally with their adjacent stream margin areas (47, 47') on reaching the impact zone (33) or earlier, overlapping to form a combined stream resulting in a central blasting area (49) jointly blasted by the two stream margin areas (47, 47') in the impact zone (33), where the blasting intensity is at least substantially equal to that produced in the stream main area (52, 53) of the two particle streams (43, 44) adjacent to the respective stream margin area (47, 47').
2. Centrifugal blast cleaning machine according to Claim 1, characterized in that the two impellers (7, 8) are located next to each other at a lateral distance at right angles to the operating direction (5).
3. Centrifugal blast cleaning machine according to Claim 1 or 2, characterized in that the two impellers (7, 8) rotate in opposite directions (38, 39) during operation.
4. Centrifugal blast cleaning machine according to any of Claims 1 to 3, characterized in that the axes of rotation (12, 13) of the two impellers (7, 8) extend in parallel and spaced axial planes (36, 37), being preferably inclined relative to the surface (4) to be cleaned.
5. Centrifugal blast cleaning machine according to any of Claims 1 to 4, characterized in that the impact zone (33) is divided into three blasting zones (49, 50, 51) immediately adjacent to or merging into each other at right angles to the operating direction (5) by the particle streams (43, 44), these being a central blasting area (49) processed by the two adjacent and overlapping stream margin areas (47, 47') and two outer blasting areas (50, 51) processed by the remaining part of the two particle streams (43, 44) and flanking the central blasting area (49).
6. Centrifugal blast cleaning machine according to Claim 5, characterized in that the outer blasting areas (50, 51) of the impact zone (33) are exclusively subjected to direct blasting by the stream main areas (52, 53) of the particle streams (43, 44) producing a greater blasting intensity.
7. Centrifugal blast cleaning machine according to any of Claims 1 to 6, characterized in that means (55) are provided to prevent outer stream margin areas (54, 54') generated at opposing outer ends of the two particle streams (43, 44) and having a lower blasting intensity than the stream main areas (52, 53) from hitting the surface (4) to be processed outside the blasting areas (50, 51) generated by the stream main areas (52, 53), expediently diverting at least the major part to the blasting area (50, 51) directly blasted by the associated stream main area (52, 53).
8. Centrifugal blast cleaning machine according to any of Claims 1 to 7, characterized in that blanking devices (55) are provided in the path of outer stream margin areas (54, 54') generated at opposing outer ends of the two particle streams (43, 44) and having a lower blasting intensity than the stream main areas (52, 53) to blank the outer stream margin areas (54, 54') from the associated particle stream (43, 44), preventing the generation of a marginal blasting zone (56) produced by them alone on the surface (4) to be cleaned.
9. Centrifugal blast cleaning machine according to Claim 8, characterized in that the blanking devices (55) are at least partially designed as reflecting devices (59) diverting the blanked outer stream margin area (54, 54') at least partially towards the outer blasting area (50, 51) processed by the associated stream main area (52, 53).
10. Centrifugal blast cleaning machine according to Claim 8 or 9, characterized in that the blanking devices (55) are represented by housing side walls (24) bordering a duct (25) for the particle streams (43, 44).

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