SCOPE OF THE INVENTION

The present invention belongs to the field of machines suitable for industrial processing and, more particularly, to the field of dry surface finishing such as shot peening, shot blasting, descaling, roughening, etc..

These processes are carried out using dedicated machines that mainly work by accelerating particles of impacting material that then hit the areas to be treated, obtaining the desired result through the physical impact between the particles and the surface being processed. BACKGROUND

The current state of the art mainly includes accelerator machines for impacting media, which consist of a lung into which the impacting medium is loaded, a flow rate dosing device and a conduit which introduces the impacting medium by fall into a distributor compartment. The distributor compartment can be assimilated to a hollow cylindrical body in rotation with the internal surface on which rectangular section cells are built, the impacting medium arriving in the distributor and colliding with the surfaces of the cells in rotation, is disadvantageously projected in every direction without accumulating in the recesses of the cells and equally disadvantageously tending to accumulate towards the bottom and adhering due to centrifugal force to the dividing surfaces of the cells, this producing a return also towards the inlet of the impacting medium. The presence of impacting material in an interspace between the distributor and the control piece generates concentric flows of particles rotating at different speeds which tend to be ejected from the discharge window in an uncontrolled manner, mainly in two concentric flows: the innermost flow tends to impact, always in the ejection step, against the outermost flow, causing fragmentation of the impacting medium and causing an incomplete outflow from the discharge window; this generates particularly accelerated wear of the flow control systems as well as an irregular exit of the impacting medium characterised by redundant rebounds with little material reaching the piece to treat it without having first undergone impacts and deviations. All this leads to disadvantages: heavy wear on the machine parts as well as on the impacting media, imbalances, replacement of parts and machine downtimes more details will follow in the discussion of the figures all of which generate a heavy increase in management and production costs, leading to longer machining times and inefficient use of the accelerator and its costly consequences, as well as generating an ejection flow where the head and tail have a very different density compared to the central area and therefore counterproductive for the machining of parts sensitive to distortions caused by unevenness or heating or hammering of the surfaces.

The present state of the art mainly includes accelerating machines for impacting media 100.0 consisting of a lung in which the impacting medium is loaded, a not represented flow rate dosing device, a conduit 1.1 which introduces by fall the impacting medium 1.0 into a distributor 1.2. the distributor can be assimilated to a hollow cylindrical body in rotation in which there are windows called cells 1.2.1 , the impacting material arriving in the distributor and colliding with the surfaces of the cells in rotation, is projected in every direction without distributing itself uniformly in the same cells, but tending to accumulate towards the bottom and to adhere, due to the centrifugal force, to the dividing surfaces of the same cells, causing its return towards the inlet. The presence of impacting material in an interspace 1.2.2 between a distributor and a control piece 1.3 generates concentric flows of particles rotating at different speeds which, in the ejection step, cause their fragmentation, leading to their incomplete outflow from the discharge window 1.3.1, thus generating a particularly accelerated wear of the flow control systems, in particular of the internal wall 1.3.2 of the orientator, as well as an outflow of the impacting medium through the vane compartment 1.6.1 , which is randomly thrown both on the whole surface of the vane 1.6 and directly on the wear wall 1.4, placed to protect the turbine-holder casing 1.5, causing redundant rebounds and minimising the quantity of impacting medium which reaches the piece to treat it without having been subjected to impacts and deviations. The distribution of the impacting medium on the vanes reflects the uneven distribution in the cells consequently causing localised wear that leads to imbalances and early replacement of the components and relative machine downtimes, generating a heavy burden in management and production costs, leading to longer machining times and a less effective use of the accelerator, also generating a wide (about 100°) exit output 1.01 which has a very uneven density of coverage and is not optimal for the treatment of parts sensitive to distortions caused by uneven heating or hammering of their surfaces.

An example of the state of the art is described in document WO 2017014767A1. It is an object of the present invention to describe a process and apparatus for accelerating impacting media that prevents rebounds of the impacting medium.

It is an object of the present invention to describe a process and apparatus for accelerating impacting media to reduce frictions and impacts between static and dynamic parts of the machine, in particular between the impacting medium and the machine.

It is a further object of the present invention to describe an accelerator for impacting media which is more economical in management both in terms of the energy required for operation and in terms of reduction of wear and tear resulting in part replacements, machine breakages and downtime, also facilitating maintenance A further object of the present invention is to describe a process and apparatus for accelerating impacting media that guides and regulates the flow of the impacting medium in an optimised manner.

Again a further object of the present invention is to describe a process and apparatus for accelerating impacting media which can reduce the sound pressure generated by processing with impacting media.

It is also an object of the present invention to describe a process and apparatus for accelerating impacting media which is more precise and rapid in processing, i.e., to generate a flow of impacting medium whose projected output surface exhibits uniform partition of the single accelerated particles with minimal variation in the shape and mass of the injected impacting medium.

It is the object of the present invention to describe a process and relative apparatus for accelerating impacting media which, characterized by a sequence of passages/steps, distinguishes the process which aims at controlling and managing the flow in each single step, distributing it in a partitioned way on all the sliding and acceleration surfaces in order to produce an output with a homogeneous distribution of at least 90% of the processed product in order to reduce deformations or flawed processing of the pieces to be treated and which responds to the request for different amplitude of the throwing angle, speed, flow rate, and throwing direction, limiting where possible wear, losses, friction, maintenance and energy consumption to achieve the necessary kinetic energy, protecting the environment, the impacting medium and the machine which also allows different operating options in order to achieve the set objectives. BRIEF DESCRIPTION OF THE INVENTION

These and further objects will be achieved by the innovative apparatus for accelerating impacting media comprising at least a machine body, an access conduit for the impacting medium within said body, a rotating distributor assembly with load cells, a discharge window and an acceleration turbine and characterised in that the conduit is a multi-flow pre-partition conduit comprising conveying channels and is connected to an injector assembly further included in the apparatus; said injector assembly comprises at least one or more chutes, said chutes constituting partitioning channels; there is also an anti wandering protection and baffles the parts being adapted to uniformly fill and without rebound one or more load cells realised in the distributor compartment.

This apparatus for accelerating impacting media also comprises a distributor assembly comprising in turn at least one or more compartment(s) of cell(s) with an inclined thrust wall for optimally orienting the impacting medium towards a discharge window also included in the distributor assembly; there is also a wear insert for controlling the same. Additionally, an orientator assembly is also included comprising at least one interchangeable window block and a compaction channel adapted to concentrate and orient the impacting medium exiting from the orientator assembly towards a turbine assembly, said turbine comprising vanes with collection compartment or vanes without collection compartment (in a variant). This orientator assembly comprises a window without an interspace to allow the passage of the impacting medium from the orientator assembly to the turbine assembly; in order to control the flow of the impacting medium, there are rebound plates and post acceleration walls.

Said monolithic or assembled orientator assembly, receives the impacting medium from the distributor and comprises a cylindrical body whose inner surface is, with respect to the circular centre of rotation, concentric or eccentric with a displacement in any position with respect to the centre, ensuring thanks to opposing centrifugal and frictional forces both continuous adherence to the surface and the free sliding in the respective seats of the inserts of the thrust walls. Finally, the apparatus for accelerating impacting media in said turbine assembly comprises vanes which are blocked to a vane-holder plate by means of a dovetailed block with dovetailed through seats. An innovative process will be advantageously linked to the innovative apparatus described here. As will be better specified in the figures discussed below, the process and apparatus for accelerating the impacting media allows for a substantial modification and control of the flow of the impacting media, in particular the multi-flow pre-partition conduit allows for an independent partition of the flow rate of the impacting medium in each single channel in the injector through the number and passage section of the channels present inside it; the injector that brings the impacting material into the distributor compartment allows, by means of chutes with suitably constructed changes of direction, to obtain a filling of the load cells present in the distributor compartment, limiting, thanks to a special protection, the wandering of the material and an optimised filling of the cells, in particular avoiding excesses of impacting material in the load cells. The distributor into which the impacting medium is conveyed also has the function of pre-accelerating the impacting material towards a compactor and orientator assembly comprising at least one block comprising one or more blocks adapted to create a channel into which the impacting material is introduced, said channel being preferably wider in the section facing the distributor compartment and narrower in the opposite part, said one or more channels concentrating and orienting the impacting material towards a turbine and more precisely towards a turbine compartment. The turbine compartment comprises said vanes with various types of profiles, flat, concave, mixed... delimited by containment walls that can be provided with at least one rebound plate, creating a new secondary collection compartment, which may, in one variant, not be present, from which the impacting material flows uniformly at high speed through a slit created between said containment wall and the rebound plate. The exit angle obtained allows the impacting medium not to collide with the casing, as well as to concentrate the working area and therefore, said casing does not need to be covered with anti-wear bodywork, with relative less space required, especially in the limited overhang of a drive shaft that will give rotational motion to the distributor and turbine.

This innovative process and apparatus for accelerating impacting media therefore makes it possible to eject the impacting medium with the maximum and homogeneous partition technically possible through the use of turbines to achieve optimal coverage of the surfaces to be treated. BRIEF DESCRIPTION OF THE DRAWINGS

These and further advantages obtained by means of the innovative device described by the present invention will be better described by means of the present illustrations, which have an explanatory and non-limiting purpose of the embodiments of the present invention.

Figs. 1a and 1b show the current state of the art of accelerating machines for impacting media, also called turbines, a side and a front section are visible.

Figs. 2a and 2b and 3a, 3b instead show the innovative process and apparatus for accelerating impacting media which is the subject matter of the present invention, again in a side and front section and in an enlarged version of the distributor compartment and the compactor/orientator assembly.

In fig. 4, variants of this process and apparatus for accelerating impacting media are shown.

DESCRIPTION OF THE DRAWINGS In Fig.1a and 1b the accelerator device for impacting media now known in the sector, in particular, a turbine unit 100.0 or turbine is represented: the impacting medium 1.0 or impacting material aO extracted from a lung silo through a flow rate dosing device, not represented and a conduit 1.1 arrives by fall and without control throughout its distribution in the compartment of the rotating distributor 1.2 of a distributor assembly falling directly into the load cells 1.2.1 ; the cells are irregularly filled and the material colliding with the rotating surfaces of said cells is projected disadvantageously towards all directions without being distributed uniformly in the same cells but accumulating towards the bottom and partly adhering by centrifugal force to the dividing surfaces of the cells a01 and partly being conveyed back towards the inlet; between the cells and a control piece 1.3 there is an interspace 1.2.2 where a part of the impacting charge is dragged by the one present in the cells, thus two concentric flows being generated and rotating at different speeds up to the discharge window 1.3.1 where the content of the cell is ejected towards the vanes 1.6 but meeting first, in a totally disadvantageous way, the flow of impacting charge present in the interspace. This leads to major disadvantages including: the fragmentation of the impacting material which will lose part of its effectiveness, the incomplete outflow of the impacting material from the window a1.3.1 and an accumulation of residues of impacting material deriving from this parasitic collision which will impact in the interspace, seriously wearing out the internal wall of the control piece 1.3. Moreover, also disadvantageously, the output of the impacting material which reaches the turbine compartment 1.6.1 between the vanes 1.6 is very expanded and in part is ejected directly against the wear walls 1.4 which protect the turbine-holder casing 1.5, wearing it out and generating a redundant counterproductive rebound against the vanes which will further reduce the quantity of impacting material which can reach the workpiece without intermediate impacts.

The distribution of the impacting medium on the vanes 1.6 reflects that of the load cells and obviously also their uneven wear, which causes imbalances, premature replacements and relative maintenance downtimes not only limited to the turbines but also involving the machines on which they are installed, since the non-homogeneous ejection output is with an angle opening of over 100° and therefore not concentrated must be directed and contained by guide plates. All this is due to the fact that the impacting medium throughout its path is not adequately controlled, leaving the phenomena of wandering free with all the associated unfavourable consequences, which will be resolved with the present invention.

Figures 2a, 2b and 3a, 3b show the innovative process and apparatus for accelerating impacting media 100.1, which will henceforth be referred to more simply as “impacting medium accelerator", seen in a side section in the representation 2a, while it is drawn in a frontal section in figure 2b; figure 3a shows a view of the distributor assembly 2.3 and the compactor/orientator assembly 2.4 for greater clarity. In particular, a conduit 2.1 being advantageously a multi-flow pre-partition conduit comprising channels 2.1 c, connected to the injector assembly 2.2, are visible.

The injector assembly 2.2 innovatively comprises one or more chutes and/or partitioning channels 2.2a and one or more anti-vagrant protection(s) 2.2b, baffles 2.2c are further provided.

There is then a distributor assembly 2.3 comprising compartments of cell(s) 2.3f with relative cell thrust walls 2.3a, and one or more wear inserts 2.3b.

The orientator assembly 2.4 is connected to the distributor assembly through a discharge window 2.3f. Said orientator assembly comprises in particular a compaction channel 2.4f, one or more window blocks 2.4e which may be interchangeable, and a window without interspace 2.4m. The outer circumference of the orientator assembly is concentric to a turbine assembly 2.8 said turbine comprising vanes with collection chamber 2.5 or, in a variant, without collection chamber 2.5.1.

Imagining now to follow the “steps” or the process to which the impacting material indicated with 2.0 is subjected and intended as impacting medium or path of the impacting material from the moment of loading in the accelerator for impacting medium until its ejection against the material to be treated, a first step a of pre-partition of the flow of the impacting material exiting of the dosing assembly is highlighted. The multi-flow pre partition conduit 2.1 , where the impacting medium exiting from a dosing assembly not represented here and not of interest is pre-partitioned into the single channels 2.1c, whose number and cross section is defined by the required flow rate, is provided with adapting flanges 2.1a /2.1b for the installations of the units in vertical, horizontal or differently inclined positions.

Step b of conveying and partitioning flow in the distributor cells. The injector assembly 2.2, the external shape of which can be freely defined, receives the material to be processed by the pre-partitioner 2.1 with which it operates in innovative synergy and conveys it through single chutes/channels 2.2a, whose terminals are shaped so that the rebound on the walls causes a change of direction that is more favourable to the uniform filling of the cell compartments 2.3e and comprises an anti-wandering protection 2.2b which limits in its interior the impacting medium being provided with baffles 2.2c to bring back in the cell compartments the residual wandering particles; said injector assembly comprises anti-slip stops 2.2h for the wear inserts 2.3b, the injector can be monolithic or assembled, the passage section of the single channels can be constant or also decreasing in proportion to the flow rate. With this embodiment, the injector assembly enables a more precise filling of the cell compartments, both in terms of the quantity of material loaded and, above all, its uniform distribution. Constructively, the blocking flange 2.2f is coupled to the rotation hub 2.2d and allows to adjust, even if in a limited way, the loading angle of the cells and the impacting medium pre-acceleration path up to the discharge window 2.4m. The anchorage of the assembly to the unit 100.1 is achieved by means of brackets 2.7b while the sliding or rebound surfaces included in the assembly are made of anti-abrasive elastic materials suitable to absorb shocks without deforming the impacting medium. Step c of low-friction pre-acceleration of the impacting medium. The distributor/pre accelerator assembly 2.3, monolithic or assembled, receives the material to be processed from the injector assembly 2.2 interspersed with slits already indicated as cells or cell compartments 2.3e, one side open for the introduction of the impacting medium, one side closed by a centring/blocking case back 2.3 with the seat of a key 2.6a and is coupled and blocked to both the drive shaft 1.12 and the vane-holder plate 2.6. The cells are identified by a thrust wall 2.3a present in the cell compartment where the loaded material is totally incorporated; said wall can be inclined, for example, between 0° and 60° with an opening angle opposite to the rotation direction and generates both the useful loading section and the shape and the angle of its ejection output, thus realising a compartment with the maximum section of the inlet mouth and the maximum passage of the impacting material, the thrust wall can be realised as a self-blocking wear insert 2.3b with a minimum thickness of, for example, about 1 mm and freely inserted in the insert seat 2.3c, thus limiting the replacement of the whole distributor body since the major wear is concentrated on the same wall. It should be noted that the particular inclination of the thrust wall offers less resistance to the outflow of the impacting medium from the cell compartment, forming a smaller angle of emission than a thrust wall normal to the tangent, as can easily be deduced from the resultant of the vector components of the motion, resulting in it being much more facilitated in the realisation of the present invention. The outer edge of the wall slides on the contrast/pre-acceleration surface 2.4a, which is held there adhered by the centrifugal force; said surface may also be constituted by the impacting medium, forced in static conditions during operation into an interspace 2.4c (a solution already present in the prior art). The output emitted by the discharge window 2.3f of the cell is in any case compact and free of wandering phenomena, fragmentations and degradation of the impacting medium.

Step d of controlled orientation and pre-concentration of the flow. The monolithic or assembled orientator assembly 2.4 receives the impacting medium from the distributor and comprises a cylindrical body whose internal surface 2.4a may be, with respect to the circular centre of rotation, concentric or eccentric with a displacement in any position up to, for example, about 7 mm with respect to the centre, guaranteeing in this last variation, thanks to the opposing centrifugal and friction forces, both the continuous adherence to the surface and the free sliding in the respective seats of the inserts of the thrust walls; said surface may be mechanically machined with low friction values and high wear resistance or, in a variant, there may be an interspace 2.4 adapted to contain during operation the quantity of impacting medium necessary to form a contrast/pre-acceleration surface with friction values corresponding to those of the impacting media which remain statically in the interspace due to a containment wall whose escape opening 2.4d towards the edge of the thrust wall of the distributor inhibits any outflow thereof; said surfaces are interrupted by a discharge window 2.4m which can be contained in the wall of the body or can protrude in an external appendage formed by an interchangeable block 2.4e provided with a fixing plate 2.4h adapted to contain a channel 2.4.f of preferably decreasing section towards the discharge and within which, the impacting medium in transit can be pre-concentrated, oriented and ejected in the optimal envisaged conformation. A discharge 2.4g placed at the rear but adjacent to the window allows any residual wandering particles to be evacuated towards the turbine. By means of a flange 2.4i with at least one reference pin 2.4.1, the loading position in the receiving vanes pos1 or pos2 is fixed, said flange being housed and locked by the bracket 2.7b in the seat incorporated in the maintenance flange 2.7a of the turbine assembly 2.8. Again, the orientator assembly allows the pre-concentration, the orientation and the reduction of the size of the flows by completing the transfer of the entire impacting medium charge into the vane collection compartment 2.5d during its transit at the discharge mouth of the channel or as represented for example in fig.4 through the window 2.4m directly both into the vane compartment and simply onto the post-acceleration surface 2.5.1.

Step e of post-concentration, homogenisation and post-acceleration of the flow. The monolithic or assembled turbine assembly 2.8 processes the incoming impacting medium and comprises more in detail one or more vanes 2.5 with a post-acceleration profile and dimensions freely definable according to the request, comprising at least one anti-wear post-acceleration surface 2.5a, at least two side containment walls 2.5b which can be provided with at least one interchangeable rebound/deflection plate 2.5c delimiting a collection compartment 2.5d with a slit 2.5e with a minimum passage space of e.g. 0.3 mm from the sliding surface, this to allow both the post-concentration and the homogeneous and controlled release of the impacting medium also determining its post acceleration path, its release point 2.5f and also the angle of the ejected output 2.5g. At least one dovetailed blockage 2.5h placed on the outside of the walls which allows the independent fixing of the vanes by means of the pins 2.6c on both the vane-holder plate 2.6 and the counterplate 2.6e with the symmetrical, dovetailed through seats 2.6b to make the blockages. The distributor assembly 2.3 is solidly blocked to the vane holder and the drive shaft 1.12 provided with at least one drive key 2.6a, while a safety screw 2.6d prevents the assembly from slipping off the shaft assembly. The vane 2.5.1 shows a variant without collection compartment 2.5d which, albeit being feasible, may not ensure the precise respect of the release point 2.5f and the full achievement of the objects.

The turbine-holder casing 2.7, thanks to its innovative flow control, does not require internal anti-wear bodywork as is disadvantageously necessary in the prior art and, in addition to the weight, it also allows the size and distance of the turbine assembly 2.8 from the motor to be limited, thus reducing vibrations. The casing can therefore be made as a monolithic or assembled realisation and comprises in a preferred embodiment example a front flange 2.7a which facilitates the maintenance of all the components, also including a system for releasing the vanes from the outside by means of a percussion pin 2.7c acting on the dovetail thereof. The components of the turbine unit 100.1 are designed for bi-directional operation.

Fig. 4 shows variants of the turbine assembly 2.8. The flow in the variant with pre acceleration on the surface of the orientator with a passage window 2.4m and the vanes in the versions with collection compartment 2.5 and without collection compartment 2.5.1 are particularly highlighted.

It should be noted that the attainment of the specific objectives of the invention can be pursued with the application combinations of the pre-distributor, the pre-partitioner, the pre-accelerator with different angles of the thrust wall, the orientator assembly with the pre-acceleration surfaces and the passage windows with/without channel, the turbine vanes with/without collection compartment, which offer a free choice of operation in accordance, however, with the claimed objects.

Basically, the present invention describes an apparatus for accelerating impacting media characterised by a sequence of steps which distinguishes the flow control and management process, avoiding fragmentations and rebounds typical of the state of the art, managing the impacting medium so that it is partitioned on all the sliding and acceleration surfaces to produce an output with homogeneous distribution and therefore reducing deformations or damages of the pieces to be treated and responding to the request for different amplitude of the throwing angle, speed, flow rate and throwing direction, limiting where possible wear, losses, friction, maintenance, energy consumption also protecting the environment, the integrity of the impacting medium and the machine parts. In this way, the main and fundamental innovation characteristic of the sector is achieved, that is, in short, obtaining the homogeneous distribution of the single particles of the impacting medium, a particularly decisive condition for the uniform treatment of surfaces subjected to work hardening, shot peening and avoiding thermally altered areas causing degradation of the mechanical characteristics of the material and penalizing deformations.