The subject of the application is a device for abrasive blast treatment of the dimensional surfaces of workpieces and the method for treatment of surfaces of dimensional workpieces, especially large-scale ones, using this device.

The abrasive blast treatment is a commonly used method for mechanical treatment of surfaces. The method is used to achieve a variety of treatment effects such as removing impurities (i.e. removing rust, scale or old coatings), preparing the surface (roughening) before applying protective and/or decorative metallic and/or organic layers, levelling out unevenness, refining, shaping or reinforcing the surface. An example of typical applications is rust removal and roughening prior to thermal spraying of metals and/or painting. The technology is widely used in industry, both in production and renovation processes.

This description refers in particular to the treatment of large-scale workpieces, whereby large-scale workpieces are understood as dimensional workpieces, each of three dimensions of which is at least 1000mm. An abrasive is understood to be any abrasive grain or other treatment media used for abrasive blast treatment, regardless of their nature and use.

The term effector or end effector means a device placed at the end of a robot arm, i.e. a multi-part kinematic mechanism, designed to interact with workpieces to be treated.

The blast nozzle is the tip of the air duct, through which the abrasive is ejected with the provided kinetic energy. It is a type of effector used for pneumatic abrasive blast treatment. Blast nozzles are usually Venturi's tubes made of abrasion-resistant material.

The impact turbine is a device driven by an electric motor, providing kinetic energy to the abrasive by the rotation of the impact wheel.

It is a kind of effector used in rotor abrasive blast treatment.

The term abrasive jet refers to a jet of abrasive grains having the kinetic energy provided by the end effector.

The hot spot is the area of the abrasive jet at the point of impact with the reference surface. Hot spots are characteristic for a specific blast nozzle or impact turbine, for a specific abrasive under specific operating conditions resulting from the specific density and impact energy of the abrasive grains on the treated surface. The blast chamber is a room adapted to perform surface abrasive blast treatment on dimensional workpieces, especially large-scale ones, usually pneumatic treatment and in this solution also rotor abrasive blast treatment. Due to the dimensions of the dimensional workpieces, the abrasive impact is dispersed.

The wheel blast machine is a commonly used device, in which impact turbines are stationary. The space in which or through which workpieces move and are exposed to the turbines is called the hot zone of the wheel blast machine due to the concentrated action of the abrasive jet.

A distinction is made between three basic abrasive blast treatment techniques, pneumatic, wheel and hydro abrasive, wherein the latter does not apply to this description.

These techniques are performed in different devices, a specific range of applications and using different control methods.

In pneumatic abrasive blast treatment technique, the kinetic energy of the abrasive is transmitted by means of compressed air. The abrasive is ejected at high speed from the blast nozzle, which is fed by a flexible rubber hose that transports the abrasive-air mixture. The blast nozzle is movable, controlled manually by the operator holding the lance in his hands, or the nozzle can be directed by means of trailing controlled mechanisms or according to a developed program.

Due to the high ejection speed of the abrasive, and the accompanying high noise level and dust generation, pneumatic treatment on large-scale workpieces is performed in blast chambers. In this case, the blast chamber is a room resistant to mechanical impact of the abrasive, equipped with a filter-ventilation system and an abrasive recirculation system, which includes, among the others, a floor (horizontal) system for transporting the abrasive, a vertical system for cleaning the abrasive, a cleaning system (dust extraction and classification of abrasive grain size). An example of a floor-based abrasive recovery system is the scraper bars moving in the corridors.

In wheel abrasive blast treatment technique, the kinetic energy of the abrasive is transmitted by impact turbines driven by an electric motor. The main element of the turbine is a rotating wheel with straight or curved blades rotating at high speed. The abrasive is driven by this rotating wheel, which uses a combination of radial and tangential forces to give the abrasive the required speed.

Inside the turbine body there is a rotating wheel, inside the body there is also a separating rotor, coaxial with an impact wheel, which is responsible for portioning the abrasive and providing initial direction and acceleration of the abrasive grains. The coaxial disposed control sleeve includes an abrasive ejection window, through which the abrasive is ejected. The position of this sleeve determines the ejection angle of the abrasive jet towards the workpiece in the form of striking waves.

There are known solutions where the treatment of large-scale workpieces is performed in wheel blast machines, which usually have multiple impact turbines installed. They are located in such a way that the abrasive jets cover all surfaces of the workpiece. The turbines are installed in the hot zone on a permanent basis (exceptionally, angular movement or movement of the dosing sleeve in the turbine is possible) in which or through which workpieces move.

As there is a concentrated amount of abrasive ejected from the turbines in the hot zone of the wheel blast machines, gravity chutes and/or transport screws are used in the recirculation system.

From an economic point of view, the wheel technique is preferable.

It is widely recognized that the energy efficiency of wheel treatment is several dozen times higher than that of pneumatic treatment. Pneumatic and wheel blast techniques differ greatly in their energy efficiency. Using the same power of about 37kW in the pneumatic technique, an ejection capacity of about 3t/h of the abrasive can be achieved, while in the rotor technique about 30t/h. The use of pneumatic nozzles is typically associated with a circular spot, and for a diameter of approx. 12 mm the nozzle can be operated manually.

When using an impact turbine, the spots are elliptical and larger than those of pneumatic treatment, thus achieving a more even surface coverage.

The turbine, due to its weight, cannot be operated manually (except for horizontal surface blast machine applications). For this reason, the workpiece to be treated is usually moved in front of the stationary turbine.

Stationary impact turbine treatment becomes less energy efficient when the workpieces smaller than the chamber's nominal dimensions allow are treated in a certain workspace. This is due to the fact that stationary turbines eject the abrasive in a fixed manner and some material does not hit the workpiece surface. To limit this negative phenomenon, for smaller workpieces, such procedures as switching off selected turbines or changing the ejection direction can be used, but this is not always possible especially when the distance between the turbine and the workpiece is constant due to the turbine's stationary nature.

Until now, a problem has been observed in the state of the art with the use of wheel blast machines for the treatment of large-scale components such as vehicles or vehicle parts, machine parts. However, it is known that for such large-scale workpieces, wheel technique would be more advantageous, as it provides a larger abrasive field than that provided by the nozzles. From the state of the art, there are mainly known devices for dimensional movement of compressed air nozzles. Document EP0165911 discloses a robotic platform for washing, sandblasting and painting ships in dry docks. The platform comprises the devices moving on rails mounted along the dock and equipped with working units, including a sandblasting unit. The document discloses the units for manipulating the working elements, but does not refer to movement of the impact turbine in the dimensional coordinate system.

The document EP3132895 discloses a sandblasting system containing an impact turbine driven by means of an axially positioned propulsion engine, which is mounted on a cleaning chamber. The impact turbine can perform pendulum movements to a very limited extent.

The document US3604157A discloses a surface treatment device containing a treatment chamber, a means of transporting a workpiece having a surface to be treated inside that chamber. For cleaning, an impact turbine is used, which can perform pendulum motion to a limited extent. The turbine is designed to access certain selected surfaces of the workpiece.

It is necessary to provide new solutions in the field of abrasive blast treatment to eliminate the disadvantages of solutions known from the state of the art. The invention according to this application meets the current demand for solutions in the field of energy-saving and possible to automate abrasive blast treatment of large-scale workpieces.

Cleaning of workpieces whose surfaces are located at different angles requires the use of multiple impact turbines, although it happens that the treatment parameters are not uniform for different surfaces of the workpiece, as the turbines must have a fixed position on the housing of the abrasive blast treatment chambers.

Due to the size of the impact turbines, it is not possible to place them any tightly next to each other, moreover, with dense spacing of the turbines it may happen that jets from two turbines reach fragments of the cleaned workpieces.

The essence of the invention is a device for abrasive blast treatment of the surface of dimensional workpieces comprising a housing, a working chamber with an abrasive recirculation system, a multi-part kinematic mechanism for moving the effector feeding the abrasive jet, a system for feeding the effector with the recirculated abrasive. The device is characterized in that the multi-part kinematic mechanism comprises a global kinematic mechanism in a two-axis Cartesian system in horizontal plane and a local kinematic mechanism, at least 2-axis implementing vertical and/or rotational motion, and in that the effector is an impact turbine mounted on the local kinematic mechanism, wherein the impact turbine being able to direct the abrasive jet to the workpiece surfaces in the working space inside the housing. The local kinematic mechanism can be a rotating telescopic assembly fixed vertically to the global kinematic mechanism.

The local kinematic mechanism may include a rotating telescopic assembly and a mechanism for rotating the turbine about an axis perpendicular to the vertical axis.

The local kinematic mechanism may comprise a rotating telescopic assembly and a mechanism for rotating the turbine around two axes perpendicular to the vertical axis.

Preferably, the device is characterized in that the impact turbine is provided with at least four degrees of freedom.

Also, preferably, the device is characterized in that the impact turbine is provided with five degrees of freedom.

Also, preferably, the device is characterized in that the impact turbine is provided with six degrees of freedom.

The device is preferably characterized in that the multi-part kinematic assembly comprises a travelling beam moving along a track, wherein the travelling trolley moves along the travelling beam, to which travelling trolley a telescopic assembly with a longitudinal axis is attached, the moving part of which carries the impact turbine.

Preferably, the impact turbine is mounted rotationally around a horizontal axis.

The impact turbine can be attached rotationally around the axis perpendicular to the longitudinal axis of the telescopic assembly.

Preferably, the device is characterized in that the recirculation system includes a scraper collecting system, which includes an abrasive corridor located in the floor section, to collect the abrasive from the working space.

Also, preferably, the device is also characterized in that the housing is in the form of a cuboidal room, wherein the track is located in the upper part of the chamber and is mounted on the housing walls.

Preferably, the device is characterized in that the impact turbine is fed by a belt conveyor located along the working space and a belt conveyor located transverse to the working space.

Also, preferably, when the impact turbine is fed from the silo by a pneumatic hose.

It is also preferably when the impact turbine is fed from an intermediate tank mounted on a travelling trolley, wherein the tank being fed from the silo in cycles. The essence of the invention is a device for abrasive blast treatment, comprising a housing providing a working space, with a filter-ventilation system, a multi-part kinematic mechanism comprising a rotatably mounted telescopic assembly, a means of providing the abrasive jet adapted to move with the moving part of the telescopic assembly and a system for recirculating the abrasive.

The device is characterized in that the mean for providing the abrasive jet is an impact turbine providing the abrasive jet, which has at least four degrees of freedom and is adapted to provide the abrasive jet at any point in the working space inside the housing.

Preferably, the impact turbine can be provided with five degrees of freedom.

Preferably, the impact turbine can be provided with six degrees of freedom.

The device is characterized in that a multi-part kinematic assembly preferably includes a travelling beam moving along the track, wherein the travelling trolley moves along the travelling beam, to which travelling trolley a telescopic assembly with a longitudinal axis is attached, the moving part of which carries the impact turbine.

Preferably, the impact turbine can be mounted rotationally around a horizontal axis.

Also, preferably, the impact turbine can be attached rotationally around the axis perpendicular to the longitudinal axis of the telescopic assembly.

The device is characterized in that the recirculation system preferably includes a scraper collecting system, which includes an abrasive corridor located in the floor section, to collect the abrasive from the working space.

The device is characterized in that the housing has preferably a form of a cuboidal room, wherein the track is located in the upper part of the chamber and is mounted on the walls of the housing.

Preferably, the impact turbine is fed by a belt conveyor located along the working space and a belt conveyor is located transversely to the working space.

Also, preferably, the impact turbine is fed from the silo by a pneumatic hose.

It is also preferably when the impact turbine is fed from an intermediate storage tank mounted on a travelling trolley, with the storage tank being fed in cycles from the silo.

In addition, the essence of the invention is the method of treatment the dimensional surfaces of workpieces by means of a device according to the invention, in which the workpiece is placed in the working space of the chamber, an abrasive jet is directed from an impact turbine to the surface of the workpiece forming an impact area of the abrasive jet, the position of the abrasive jet in the working space is changed within three axes, the abrasive jet is rotated around at least one axis.

Preferably, the method is characterized in that the abrasive jet is rotated in two axes.

Preferably, the method is characterized in that the abrasive jet is rotated in three axes.

The device according to the invention provides high energy efficiency of the treatment process due to the use of a wheel impact turbine, which allows treatment of larger surfaces than in case of the use of pneumatic nozzles. The device can be used to clean the surfaces of differently shaped workpieces, especially those of large-scale dimensions. The device according to the invention ensures obtaining uniform parameters for variously situated surfaces of the workpiece with the use of one impact turbine. It is extremely advantageous that the workpiece treated with the device according to the invention is subjected to the treatment process without the need to move in the chamber. The disclosed abrasive blast treatment chamber is fully robotic, allowing the treatment to be automated.

The subject matter of the invention is described below according to the embodiments shown in the drawing, on which:

Fig. 1 shows a schematic perspective view of the device according to the invention,

Fig. 2a shows a schematic view of a multi-part kinematic mechanism for moving the impact turbine according to the first embodiment,

Fig. 2b schematically shows the method of changing the direction of the abrasive jet of the mechanism from Fig. 2a,

Fig. 3a shows a portion of a multi-part kinematic mechanism according to the second embodiment,

Fig. 3b schematically shows the method of changing the direction of the abrasive jet of the mechanism from Fig. 3a,

Fig. 4a shows a portion of a multi-part kinematic mechanism according to the third embodiment,

Fig. 4b schematically shows the method of changing the direction of the abrasive jet of the mechanism from Fig. 4a,

Fig. 5 shows a device with a pneumatic feeding system, Fig. 6 shows a device with a feeding system equipped with belt conveyors,

Fig. 7 shows a device with a feeding system equipped with a stationary silo and a mobile storage tank.

Fig. 1 shows the device 1 for abrasive blast treatment. Device 1 includes housing 2, which is a hermetic closure for the space, which is the working chamber and in which the treatment is performed, wherein, for clarity of the drawing, the device is shown without front and rear wall. In addition, device 1 is equipped with a filter- ventilation system 3, which ensures that the air in device 1 is filtered and exchanged. Device 1 includes an abrasive recirculation system 4, which allows the device to operate in a closed circuit of abrasive circulation. Recirculation system 4 includes a system 5 of scraper-type abrasive transport located in the floor, known for example from patent application P402365. Fig. 1 shows an example of a P workpiece to be treated. The P workpiece is usually positioned so that the workpiece surfaces to be cleaned, were located in workspace W, i.e., essentially rectangular space, in which an abrasive jet can be applied to the workpiece surface.

According to the invention, there is an impact turbine 6 for abrasive blast treatment, which is moved by the multi-part kinematic mechanism 7 of the device

I. The multi-part kinematic mechanism 7 may have its own supporting structure or may be mounted on a reinforced housing 2 as in an embodiment shown in Fig. 1. The multi-part kinematic mechanism 7 is adapted to move the impact turbine 6 in three directions determined by the X, Y, Z axes of the dimensional coordinate system. The global movement in X direction is performed by moving the traveling beam 8 along track 9. The movement in Y direction performed by moving the trolley 10 along the traveling beam 8. Track 9, travelling beam 8 and trolley 10 may have the form of a gantry crane. The movement mechanism of the travelling beam is a global kinematic mechanism. The global kinematic mechanism may include a guide located on one side of the chamber only, wherein the guide may be located at any height, also by the floor.

A telescopic assembly 11 (Fig. 2a) is mounted rotationally on the travelling trolley 10, wherein the telescopic assembly 11 can be driven by means of a gear 12. The impact turbine 6 is attached to the retractable part 13 of the telescopic assembly

II. The rotationally mounted telescopic assembly 11 ensures that the impact turbine 6 can be moved in the direction of the Z-axis and the impact turbine 6 can be rotated around the k-axis parallel to the Z-axis; in an embodiment shown, the impact turbine 6 can be rotated through an angle g in the range of 360°. The rotationally mounted telescopic assembly 11 enables regional movement of the impact turbine, i.e. movement that brings the turbine to the designated points on the workpiece. Thanks to the applied multi-part kinematic mechanism 7, the impact turbine 6 can move in a three-dimensional coordinate system and rotate around one of the axes, and thus has provided four degrees of freedom. Any other multi- part kinematic mechanism can be used to provide the impact turbine 6 with four degrees of freedom. In order to define the operation of the device, it is possible to distinguish between global motion, which is only motion along the X axis, regional motion, which aims to move the impact turbine to the treatment site, and local motion, which is a combination of motion towards the Z axis and the motion of the turbine itself, both rotary and swinging and twisting, described below. In simple terms, only the global kinematic mechanism enabling to move the turbine to the treatment site and the local kinematic mechanism enabling to maneuver the turbine at the treatment point can be distinguished.

In the further part of the description it has been assumed, for simplicity, that the direction of the abrasive feed, i.e. the direction of the abrasive jet is described by the S axis situated centrally along the abrasive jet delivered from the impact turbine 6. In an embodiment of device 1 described above, as shown in Fig. 2b, the S axis may rotate around the vertical axis k situated parallel to the Z axis of the dimensional coordinate system and move in the X, Y, Z directions in this system, wherein only a few examples of local motion positions of the turbine around the k axis being shown. The k axis can be inclined relative to the Z axis.

The multi-part kinematic mechanism 7 allows the impact turbine 6 to move inside housing 2 and direct the abrasive jet to the surfaces to be cleaned in the working space W. Device 1, according to the invention, can be adapted to process stationary or moved workpieces during treatment, wherein large-scale workpieces, such as vehicle bodies, usually being immobile during treatment. It is possible to treat parts of the surface of the cleaned workpiece P, and then, after moving the workpiece P, to treat the remaining surfaces of this workpiece. During treatment, the impact turbine 6 directs the abrasive jet to the surfaces of the workpiece which are in the W workspace. The impact turbine 6 can move both around and within the W workspace. The device 1 for abrasive blast treatment according to the invention allows the material jet to be delivered in such a way as to maintain the optimum and uniform treatment conditions of the workpiece for the differently oriented surfaces of the workpiece, especially to maintain the optimum direction of the jet feed in relation to the surface and the optimum distribution of the treatment spots, i.e. in such a way that the treatment spots overlap to a minimum extent.

Fig. 3a shows an impact turbine 6 mounted rotationally on the moving part 13 of the telescopic assembly 11, the impact turbine 6 on arm 14 can rotate around the axis m. The axis of rotation m is essentially horizontal. For simplicity, the drive mechanism is not shown, a gear may be used for drive. In the embodiment shown, the turbine's axis of rotation m is offset from the axis of rotation k, which is the longitudinal axis of the telescopic assembly 11, wherein an embodiment is possible in which the axis of rotation m intersects the axis of rotation k. The impact turbine 6 can be rotated by an angle b in the range from -90° to 90°. For an impact turbine 6 mounted in this way, the abrasive jet axis S can rotate around the k-axis and around the m-axis. Fig. 3b shows two example positions of the impact turbine 6 and the abrasive jet axis S, the figure shows the turbine outlet itself in simplified form. Turbine 6 in the first position is facing downwards at an angle of bΐ, turbine 6' is in the position after rotation upwards around the k axis by 180° and is located at an angle of b2 with respect to the m' axis shown after rotation, i.e. there is a change in the angular position with respect to the m axis. The impact turbine 6 has the possibility to rotate around the two axes k and m and can move according to the X, Y, Z directions in the dimensional coordinate system, so it has five degrees of freedom, and turbine 6 can direct the abrasive jet from the side to the workpiece as well as from below and above. The impact turbine 6 can perform more complex local movements, for example inside workpieces.

In addition, the impact turbine 6 can be mounted rotationally around the axis of rotation n on the moving part 13 of the telescopic assembly 11 as shown in Fig. 4a, the impact turbine 6 is mounted on the rotary bearing assembly 15, but for simplicity, the drive unit is not shown. The axis of rotation n is essentially perpendicular to the longitudinal axis k of the telescopic assembly 11. The impact turbine 6 can be rotated by an angle of f in the range from 0° to 90°. The impact turbine 6 mounted in this way has six degrees of freedom, which allows to direct the abrasive jet onto hard to reach workpiece surfaces. Fig. 4b presents two example positions of the impact turbine 6, in one position the impact turbine 6 is angled by cpl from the position in Fig. 4a, while in the other position the impact turbine 6 is angled by cp2 larger than cpl. The impact turbine 6 having six degrees of freedom can make any local movements. The local kinematic mechanism is adapted to perform vertical movement and rotation around three axes.

The impact turbine 6 can be fed from silo 16 via pneumatic hose 17 as shown in a simplified manner in Fig. 5. Pneumatic hose 17 is flexible and is adapted to the effective delivery of abrasive over the entire range of motion performed by the impact turbine 6.

The impact turbine 6 can be fed from silo 18 (Fig. 6), from which the abrasive is received and transferred by means of belt conveyor 19 located along chamber 1, in direction X and further on by means of belt conveyor 20, transversely to the chamber in direction Y, to chute 21 and through hose 22 to the impact turbine 6. The transfer of the abrasive from conveyor 19 to conveyor 20 can be performed by means of scraper element 23, and from conveyor 20 to chute 21 by means of scraper element 24.

Fig. 7 shows a feeding system in which an intermediate tank 26 is mounted on the trolley 10, which is fed from silo 25 in cycles. The operating cycle of the impact turbine 6 is dependent on the required abrasive feed capacity during treatment and the capacity of the intermediate tank 26. The abrasive is delivered to the impact turbine 6 through the feeding hose 27. The device for abrasive blast treatment is equipped with an abrasive recirculation system, which includes an abrasive transport corridor, a system for separating the abrasive from dirt and a transport system. The device can be equipped with one or more parallel abrasive transport corridors such as shown in the application description P402365 and is optionally equipped with a transverse abrasive transport corridor. The abrasive transport corridor is preferably located in the floor, wherein a traction system along this corridor to move the wheeled unit along the transport track to move the workpiece to be treated. The corridor with the traction system may be placed centrally along the chamber, with the transport track in the form of rail elements arranged on both sides of the corridor. The removal of the abrasive is preferably performed by means of a scraper system working in a reciprocating motion so that the abrasive is moved evenly along the corridor. Alternatively, the discharged abrasive can be delivered to the turbine feed silo first horizontally by a screw conveyor or pneumatically and then vertically by means of a bucket conveyor. As part of the implementation of the invention, it is also possible to use other systems for recirculating the abrasive.

In order to control the movements of the impact turbine it is necessary to control the individual components of the multi-part kinematic mechanism. For this purpose, a commercially available programmable controller can be used, which performs the tasks of simple and reverse kinematics, with servo controllers of the mechanism parts. The controller enables the implementation of own kinematic chains using the mentioned modules to control the tool central point (TCP), i.e. the turbine and the calculation of the position of individual axes of the system.

In the scope of knowledge of the skilled person will be to adapt commercially available control and monitoring systems according to the invention, e.g. SEW- EURODRIVES provides such solutions in the form of the Motion Control platform "MultiMotion" with the additional technology module "Kinematics".

The abrasive jet impact area, the so-called hot spot, as mentioned above, is characteristic for a specific impact turbine, for a specific abrasive under specific operating conditions resulting from the specific density and impact energy of the abrasive grains with a reference surface. The skilled person will design the operating conditions of the device each time so as to adapt the abrasive jet impact area to the dimension of the workpiece, its material and abrasive as well as the type of treatment. Within the scope of the skilled person knowledge will be the implementation of the method according to the invention, where the position and/or force of the abrasive jet flowing out of the impact turbine will change as programmed, resulting in obtaining an appropriate abrasive jet impact area with the surface of the workpiece. The device according to the invention provides the possibility of changing the position of the abrasive jet within the chamber in three axes and rotating the abrasive jet around at least one axis to provide at least four degrees of freedom, preferably five and also six degrees of freedom. The kinematic mechanism, depending on its specific design, can of course achieve more than six degrees of freedom.

Thanks to the design of the device according to the invention, it is possible to regulate (in a wide range): the shape and density of the abrasive jet, the speed and direction of its impact, as well as the force of the impact on the surfaces to be cleaned, which can be achieved, among others, by means of distance or inclination of the effector to the surface of the workpiece, which has not been possible so far for abrasive blast treatment with the use of an impact turbine.