EP3132895B1 - Sand blasting system with an oscillating impeller wheel - Google Patents

Description

The invention relates to a sand blasting machine with a blast wheel, which is driven by an axial drive motor and pivotally mounted about a first axis of rotation, which is approximately perpendicular to an axis parallel to the motor axis of the drive motor on a beam saddle, wherein the first axis of rotation on the beam saddle below the Impeller is arranged, and wherein a first electromechanical adjusting device is present, by means of which the impeller is movable in different desired pivot angle with respect to the first axis of rotation.

Such a sandblasting machine is known US Pat. No. 3,604,157 A ,

Sandblasting is a process for surface treatment in which a workpiece is irradiated with a blasting medium such as sand, but also steel, ceramic or glass beads. Simple examples can be found in nature: a stone that lies in the desert becomes ever rounder and smoother over time because the desert sand abrades the stone. If instead of the stone a glass pane lies in the desert, it gets grinding marks and becomes ever more dull and rougher. Depending on how strong the wind and how big the grains of sand are, the results differ.

Even these simple examples show that sandblasting can achieve completely different effects. Burrs can be removed, edges rounded, surfaces smoothed or roughened. Likewise, parts can be cleaned or blasted for visual reasons. Various factors play a role here: blasting media, material and condition of the workpiece, mode of operation, and intensity and duration of blasting.

Instead of desert sand, the most diverse materials are used in industrial sandblasting - depending on the application. These include steel, stainless steel, aluminum, glass beads, ceramics, garnet or corundum. Occasionally one also uses nut shell or corn cob granules. The grain size is between 0.1 mm and almost 8 mm. The blasting agent can also be spherical or edged. The different physical properties of these materials result in different beam results. These can additionally be varied by the amount and speed of irradiation. In some cases, mixtures of different blasting agents are also used. When choosing the blasting medium, one also takes into account the material of the workpiece to be blasted. For example If a stainless steel part should not be processed with normal steel, otherwise tiny inclusions in the stainless steel can lead to rust formation.

• Entfernen von Graten nach dem spanenden Bearbeiten von Werkstücken;
• Aufrauen von Oberflächen als Vorbereitung fürs Lackieren oder Kleben;
• Entfernen von Rost;
• Ausgleichen von Verfärbungen, z. B. durch Schweißen oder Erhitzen;
• Verfestigen von Oberflächen durch Kugelstrahlen.

The sand blasting method can be used, for example, for:

• Removing burrs after machining workpieces;
• Roughening surfaces as a preparation for painting or gluing;
• Removing rust;
• Compensation of discoloration, z. By welding or heating;
• Solidification of surfaces by shot peening.

The stone in the desert must lie there for quite a while to be smoothed off by the sand. With professional sandblasting, much shorter machining times are typical because you can increase the amount of blasting abrasive and the intensity (speed) at which it hits the workpiece considerably. In order to achieve this, essentially three different methods are used:

Injector blasting with compressed air for light sandblasting:

This is a very simple principle that can be implemented without great technical effort. However, since the blasting medium is only accelerated in the nozzle, the efficiency is relatively low. Only if light radiation is sufficient can the desired results be achieved.

Pressure blasting for targeted sandblasting:

Another technique of sand blasting with air pressure is pressure blasting. Here, the blasting agent is first collected in a pressure vessel and then pressed into a hose for blasting. At the same time compressed air is passed through the hose, which entrains the blasting agent. At the end of the hose there is a nozzle, which allows a targeted blasting. Over the diameter of the nozzle, the amount of blasting agent can be adjusted.

The present invention, however, used Blower wheels for efficient, automatic sandblasting:

Centrifugal wheels are suitable for accelerating the blasting medium in stationary systems for automatic sandblasting. It is a disc on which several throwing blades are attached. The abrasive falls through a tube in the center of the disc and is then captured by the blades. The centrifugal force accelerates the blasting medium and throws it onto the object to be blasted. In general, a guide sleeve is used, which is located in the center of the blast wheel to set the direction of the blasting medium. This technique uses no compressed air to accelerate the jet and thus has a much higher and more efficient throughput. It can be accelerated far more than 100 kg blast media per minute. At blast wheel blast systems usually more than one blast wheels are used simultaneously. Sandblasting systems with such blasting wheels, which have the features defined above, are shown and described on the above-cited Internet page of the company AGTOS.

Object of the present invention is therefore in contrast, a generic sandblasting machine with blast wheel of the above described type with the simplest possible technical means and economically inexpensive to improve the effect that a significantly larger angular range can be sandblasted simultaneously on the workpiece to be machined. In addition, the inventively improved construction should have an increased mechanical stability and finally also allow at least remote controlled, better still an automated operation of the sandblasting system, the blast wheel can be moved simultaneously or nacheinanderogar in 2 axes, so that three-dimensional curves on the workpiece Surface "can be traversed".

According to the invention this - perhaps simple-sounding, but on closer inspection but relatively demanding - task in a surprisingly simple and effective way, starting from a sandblasting system with the features defined above achieved in that the blast wheel is pivotable about a further axis of rotation, parallel to the motor axis of the drive motor and at a distance from this runs, and that a further electromechanical adjusting device is present, by means of which the impeller can be moved in different desired pivoting angle also with respect to the further axis of rotation.

In this way, due to the deep arrangement of the first axis of rotation at the height of the beam saddle below the impeller counterpart to the above cited closest prior art, where the first axis of rotation above the beam saddle runs through the center of the impeller creates a mechanically particularly stable structure and a in view of the durability of the attachment considerably improved arrangement.

Above all, however, by means of the first electromechanical adjusting device prescribed according to the invention, the impeller can be moved into various desired pivoting angles with respect to the first axis of rotation, so that ultimately a significantly larger angular range can be swept over for machining, whereby considerably larger surfaces of a workpiece can be machined in the same unit of time , which results in a much more economical operation of the sand blasting machine.

In addition, the introduction of an electromechanical adjusting device allows a remote controlled and permanent, in particular continuous adjustment of the pivoting angle of the centrifugal wheel with respect to the first axis of rotation, so that an automated operation of the sandblasting system with -in principle even constantly changing different beam angles and thus a uniform and complete processing of the desired workpiece surfaces improved work results with less time and cost over the known from the prior art systems.

The company Wheelabrator Group GmbH in D-48629 Metelen also offers a so-called oscillating centrifugal wheel. Here, however, is not - as the title would suggest - the spinner itself oscillating, but the entire beam saddle oscillates. Such a construction is of course very complex and costly to manufacture, requires considerably more space and is therefore very different from the invention described above.

By the spinner is pivotable about a further axis of rotation, which is parallel to the motor axis of the drive motor and at a distance from this, the spinner can be moved simultaneously or nachogasogar in 2 axes. Due to the achievable thereby Beam effect can therefore be said to be a "3D blast wheel", because three-dimensional curves on the workpiece surface can also be "traversed" with it.

This type of movement of the centrifugal wheel has the advantage that the jet angle can now be pivoted in the horizontal direction in addition to the vertical pivoting described above.

The fact that the further axis of rotation on the jet saddle is again arranged below the centrifugal wheel, a particularly high mechanical stability is achieved. In addition, a further electromechanical adjusting device is provided, by means of which the centrifugal wheel can be moved in different desired pivoting angle also with respect to the further axis of rotation and independently of the first pivoting movement.

One class of particularly preferred embodiments of the invention is characterized in that the electromechanical adjusting devices can continuously adjust the respective pivoting angle of the centrifugal wheel. This makes it possible to achieve an almost arbitrary surface coverage for machining workpiece surfaces.

An alternative class of embodiments of the invention is characterized in that the electromechanical adjusting devices can adjust the respective pivoting angle of the impeller in discrete steps. In this way, certain predefined angular ranges can be better processed.

In preferred embodiments of the sand blasting installation according to the invention, the electromechanical adjustment devices can be electrically or electronically controlled, in particular controllable. In this way, the desired beam angle range can be individually programmed and entered according to the corresponding geometry of the surface (s) of the workpiece to be machined in order to enable automated machining ,

Advantageous developments of these embodiments, in which the electromechanical adjusting devices are each provided with a forward and reverse drive unit, in particular a drive spindle for mechanical rotation axis adjustment of the impeller and an electric motor drive, the electromotive drive is preferably clocked controlled. Such a drive is low-wear and ensures a high durability and a low-interference, usually even trouble-free operation between the maintenance intervals. The possible degree of process automation increases and the sandblasting system according to the invention can therefore already be operated particularly cost-effectively.

Embodiments of the invention are particularly preferred, which are characterized in that the electromechanical adjusting devices can each cause a continuous, in particular in forward and backward direction oscillating, pivoting of the impeller. This can be a further, very significant time savings in the processing of workpiece surfaces realize. The resulting possibility for processing larger surface areas of the workpiece in the same time units also results in a significant reduction of unwanted "cloud formation" (= shadow through non-illuminated areas). The result will be even more even.

A group of developments of these embodiments is characterized in that the electromechanical adjusting devices each have an adjustable frequency controller which controls the desired oscillation speed of the oscillating Verschwenkwinkel-adjustment of the impeller. Thus, the respectively just irradiated areas of the workpiece surface (s) to be processed can be swept faster or more slowly with the blasting medium. This allows a very individual adjustment of the currently used working mode, depending on the nature of the workpiece and also depending on the desired work result.

Further advantageous embodiments of the invention are characterized in that the first electromechanical adjusting device is arranged parallel to the motor axis of the drive motor. This makes the system extremely compact and space-saving.

Likewise embodiments are advantageous in which the further electromechanical adjusting device is arranged along an axis which is perpendicular to an axis parallel to the motor axis of the drive motor axis, so that complicated force-deflection mechanisms are not required.

Also advantageous are embodiments of the sand blasting machine according to the invention, in which the blasting saddle is sealed in order to avoid damage and with the aim of the longest possible durability in operation against ejected blasting particles.

These embodiments can be advantageously further developed by the jet saddle has a labyrinth seal, which structurally particularly simple, maintenance-free in principle, and thus can be made extremely durable.

Finally, further developments of all the above-described embodiments of the sandblasting system according to the invention are advantageous, in which the jet saddle and optionally its seal are made of high-alloy tool steel to achieve a particularly high wear resistance to particulate particles, which in operation usually with high kinetic energy on the impinge on the relevant surfaces of the installation.

Further features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention with reference to the figures of the drawing, which shows details essential to the invention, and from the claims. The individual features may be implemented individually for themselves or for a plurality of combinations in variants of the invention. In the schematic drawing embodiments of the invention are shown, which are explained in more detail in the following description.

Fig. 1

eine räumliche Darstellung einer ersten Ausführungsform der erfindungsgemäßen Sandstrahlanlage mit einem um eine erste Drehachse verschwenkbaren Schleuderrad;

Fig. 2a

die Ausführungsform nach Fig. 1 in schematischer Ansicht von der Seite;

Fig. 2b

die Ausführungsform nach Fig. 1 in schematischer Ansicht von oben;

Fig. 3

die Ausführungsform nach Fig. 2a in schematischem Vertikalschnitt durch die Sandstrahlanlage;

Fig. 4

eine räumliche Darstellung einer weiteren Ausführungsform der erfindungsgemäßen Sandstrahlanlage mit einem sowohl um eine erste als auch um eine weitere Drehachse verschwenkbaren Schleuderrad;

Fig. 5a

die Ausführungsform nach Fig. 4 in schematischer Ansicht von der Seite; und

Fig. 5b

die Ausführungsform nach Fig. 4 in schematischer Ansicht von vorn in Blickrichtung der Motorachse des Antriebsmotors.

In detail show:

Fig. 1

a spatial representation of a first embodiment of the sand blasting machine according to the invention with a swivel wheel pivotable about a first axis of rotation;

Fig. 2a

the embodiment according to Fig. 1 in a schematic view from the side;

Fig. 2b

the embodiment according to Fig. 1 in a schematic view from above;

Fig. 3

the embodiment according to Fig. 2a in a schematic vertical section through the sandblasting system;

Fig. 4

a spatial representation of another embodiment of the sandblasting system according to the invention with a both about a first and about a further axis of rotation pivotable impeller;

Fig. 5a

the embodiment according to Fig. 4 in a schematic view from the side; and

Fig. 5b

the embodiment according to Fig. 4 in a schematic view from the front in the direction of the motor axis of the drive motor.

The embodiments shown schematically in detail in the figures of the drawing each show an inventively designed sandblasting system 10; 40 with pivotable impeller 11 . This is driven by means of an axial drive motor 12 and pivotally mounted on a beam saddle 14 about a first axis of rotation 13 which is perpendicular to an axis parallel to the motor axis of the drive motor 12 axis. According to the invention, the sandblasting system 10; 40, characterized in that the first axis of rotation 13 is disposed on the beam saddle 14 below the impeller 11, and that a first electromechanical adjusting device 15 is present, by means of which the impeller 11 in different desired pivot angle with respect to the first axis of rotation 13 is movable.

In the FIGS. 1 . 2a . 2 B and 3 such a sandblasting machine 10 according to the invention with a single pivot axis for the blast wheel 11 is shown in detail from different sides.

The FIGS. 4 . 5a and 5b On the other hand, an embodiment of the sand blasting machine 40 according to the invention, which is characterized in that the blast wheel 11 is pivotable about a further axis of rotation 43 which is parallel to the motor axis of the drive motor 12 and at a distance therefrom. This further rotation axis 43 is again arranged on the beam saddle 14 below the spinner wheel 11. In addition, a further electromechanical adjusting device 45 is present, by means of which the centrifugal wheel 11 can be moved in different desired pivoting angle with respect to the further rotation axis 43.

In all embodiments of the sandblasting system 10 according to the invention; 40, the electromechanical adjusting devices 15; 45 adjust the respective pivot angle of the spinner 11 continuously or in discrete steps.

The electromechanical adjusting devices 15; 45 are usually controlled electrically or electronically, in particular controllable, and each provided with a forward and reverse drive unit, in particular a drive spindle, for mechanical rotation axis adjustment of the impeller 11 and with an electric motor drive, the electromotive drive is preferably clocked controlled.

In a particularly preferred embodiment of the sandblasting system 10 according to the invention; 40 are the electromechanical adjusting devices 15; 45 designed so that they can each cause a continuous, in particular in the forward and backward direction oscillating, pivoting of the impeller 11. In particular, they each have an adjustable electronic frequency controller, not specifically shown in the drawing, which controls the desired oscillation speed of the oscillating pivot angle adjustment of the impeller 11.

The first electromechanical adjusting device 15 is arranged parallel to the motor axis of the drive motor 12, while the further electromechanical adjusting device 45 is arranged along an axis which is perpendicular to an axis parallel to the motor axis of the drive motor 12 axis.

The jet saddle 14 is usually sealed against ejected jet particles and has at the in Fig. 3 illustrated embodiment of the invention, a labyrinth seal.

LIST OF REFERENCE NUMBERS

10; 40

Sandstrahlanlage

11

blower

12

drive motor

13

first axis of rotation

14

beam saddle

15

first electromechanical adjusting device

43

another axis of rotation

45

further electromechanical adjusting device

Claims (12)

1. Sandblasting system (10; 40) comprising an impeller (11) driven by means of an axial drive motor (12) and mounted on a support (14) in such a manner that it is pivotable about a first axis of rotation (13) extending perpendicularly to an axis parallel to the motor axis of the drive motor (12), wherein the first axis of rotation (13) is arranged on the support (14) below the impeller (11) and wherein a first electromechanical adjusting device (15) by means of which the impeller (11) can be positioned at different desired pivot angles in relation to the first axis of rotation (13) is provided, characterised in that the impeller (11) is pivotable about a further axis of rotation (43) extending parallel to the motor axis of the drive motor (12) and at a distance therefrom, that the further axis of rotation (43) is also arranged on the support (14) below the impeller (11) and that a further electromechanical adjusting device (45) by means of which the impeller (11) can be positioned at different desired pivot angles also in relation to the further axis of rotation (43) is provided.
2. Sandblasting system according to claim 1, characterised in that the electromechanical adjusting devices (15; 45) can adjust the respective pivot angle of the impeller (11) continuously.
3. Sandblasting system according to claim 1, characterised in that the electromechanical adjusting devices (15; 45) can adjust the respective pivot angle of the impeller (11) in discrete steps.
4. Sandblasting system according to one of the preceding claims, characterised in that the electromechanical adjusting devices (15; 45) can be actuated, in particular controlled, electrically or electronically.
5. Sandblasting system according to claim 4, characterised in that the electromechanical adjusting devices (15; 45) are each provided with a forward and backward running drive unit, in particular a drive spindle, for mechanical adjustment of the axis of rotation of the impeller (11), as well as with an electromotive drive, wherein the electromotive drive can preferably be actuated in a synchronised manner.
6. Sandblasting system according to one of the preceding claims, characterised in that the electromechanical adjusting devices (15; 45) can each effect continuous pivoting of the impeller (11), in particular oscillating in a forward and backward direction.
7. Sandblasting system according to claim 6, characterised in that the electromechanical adjusting devices (15; 45) each have an adjustable frequency controller that controls the desired oscillation speed for the oscillating adjustment of the pivot angle of the impeller (11).
8. Sandblasting system according to one of the preceding claims, characterised in that the first electromechanical adjusting device (15) is arranged parallel to the motor axis of the drive motor (12).
9. Sandblasting system according to one of the preceding claims, characterised in that the further electromechanical adjusting device (45) is arranged along an axis extending perpendicularly to an axis parallel to the motor axis of the drive motor (12).
10. Sandblasting system according to one of the preceding claims, characterised in that the support (14) is sealed off from ejected sandblasting particles.
11. Sandblasting system according to claim 10, characterised in that the support (14) has a labyrinth seal.
12. Sandblasting system according to either of claims 10 or 11, characterised in that the support (14) and its seal are produced from high-alloy tool steel.

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