FR3142111A1 - System for adjusting and prestressing the surface of a part - Google Patents

Abstract

Adjustment and prestressing system comprising at least two adjustment and prestressing tools (1) and a support configured to hold a part to be treated (6), the system comprising means for rotating the adjusting tools and prestressing, each adjustment and prestressing tool (1) comprising at least two fins arranged on either side of a rod, each fin comprising balls and abrasive surfaces on at least one side encapsulated in a varnish, the adjustment and prestressing tools (1) being arranged so that the balls and abrasive surfaces on their fins successively come into contact with the surface of the part to be treated (6) during their rotation in order to adjust the surface and to generate a compression Figure for the abstract: Fig 4

Description

System for adjusting and prestressing the surface of a part

The technical field of the invention is adjustment tools, and compression or compaction.

Previous techniques

The projection of media by spraying is used for numerous applications such as stripping, cleaning/stripping of polluted surfaces (oxidized or corrosion products), the compression of surfaces subjected to mechanical fatigue in order to delay the initiation and propagation crack, the compaction of inorganic paints with aluminum pigments so as to give them the character of a sacrificial anode allowing the protection of steel surfaces against atmospheric corrosion phenomena.

Shot peening allows compression to be carried out by projecting metallic media (steel balls) or ceramic media (glass beads, oxides, etc.) onto the surface of a part to be treated. Compression results from the conversion of the kinetic energy of the projected media into plastic deformation upon impact against the surface to be treated.

Shot blasting by media blasting, and even more so sandblasting or abrasive blasting, can leave media residues encrusted on the surface of the treated part, at the interface between the surface and a coating or on the surface of the treated coatings. These residues can have deleterious effects on:

- The mechanical properties of the substrate in the case of encrustation of hard abrasive media (for example, corundum) which can generate a reduction in fatigue and the endurance limit,

- Corrosion behavior in the case of encrustation of media subject to oxidation (for example, steel balls encrusted on titanium substrates),

- The release of hard particles (for example, corundum) which may call into question the functional integrity of certain parts of a subassembly located downstream of the treated part, and

- Have a detrimental impact on the adhesion of coatings when they are trapped at the substrate/coating interface.

These different encrustation phenomena generally require chemical or mechanical decontamination operations to be carried out, or to have strategies in place to trap the encrusted media in order to prevent their release (for example, application of paint in two layers to trap the media on the surface of the first layer).

Sometimes when media blasting is carried out on difficult to access areas or in the case of touch-ups, it may be necessary to re-blast an area. Re-blasting a small surface area requires protecting the rest of the part, where shot-blasting must not be carried out again, in order to avoid over-blasting of areas adjacent to the retouched area which could thus create surface defects. (bulge, folds of material, etc.). This masking step is often a long, tedious and delicate operation to carry out. This operation can also be the cause of the appearance of new defects during handling operations or when masking is difficult.

There is also a need for a shot blasting device and process that minimizes the risks of media encrustation.

A response to these needs can be found in roto-shot blasting.

Rotoblasting is a local compression process, which is generally used on a previously adjusted surface, using a flexible or non-flexible abrasive tool. The roto-shot peening tool is composed of a rod on which is fixed a strip impregnated with resin with one or more rows of balls (for example from 1 to 4 rows each comprising 4 to 16 balls) made of tungsten carbide. The strip is rotated using a portable device so that the carbide balls impact the surface to be treated and introduce residual compressive stresses. Media encrustation is also a risk with rotary blasting. This risk is, however, much more limited than in the case of shot peening by media projection or in the case of sandblasting or adjustment by abrasive projection.

Implementation of this process for local compression of a retouched area first requires preparation of the surface by adjustment with a soft abrasive then cleaning of the adjusted surface. If the preparation of the surface is not carried out sufficiently well, verification of the effectiveness of the operation via visual examination is not possible. It is then necessary to repeat the adjustment operation. If cleaning is not carried out, dirt or pollution may become embedded in the material during shot blasting or compression.

In addition, rotary shot blasting is a manual process which is currently not well suited to treating an entire part, both from an economic point of view and from a processing time point of view.

There is therefore a problem with compression without leaving any media encrustation in the treated surface.

There is also a problem regarding the need to carry out decontamination after shot blasting or compacting in order to guarantee the integrity of the treated part.

Finally, there is a problem regarding the processing time or cost of roto-blasting entire parts.

The subject of the invention is an adjustment and prestressing system comprising at least two rotary tools and a support configured to hold a part to be treated, the system comprising means for rotating the rotary tools as well as a control means , each rotary tool comprising at least two fins arranged on either side of a rod, each fin comprising balls and/or abrasive surfaces on at least one face, the rotary tools being arranged so that the balls and/or or abrasive surfaces on their fins come into contact with the surface of the part to be treated during their rotation in order to adjust the surface and generate compression, the control means being configured so as to control coordinated rotation rotating tools.

A rotating tool may include at least one fin provided with abrasive surfaces and at least one fin provided with balls.

A rotating tool may include at least one vane provided with both abrasive surfaces and balls.

A fin may be provided with an encapsulation layer to prevent beads or particles from the abrasive surfaces from becoming detached

At least one rotating tool may be arranged such that the direction of its shank is perpendicular to the direction of the shank of at least one other rotating tool.

The part to be treated arranged in the support can extend from the support along a longitudinal axis, at least two rotating tools then being arranged so that the direction of their rod is parallel to the longitudinal axis of the part to be treated

The part to be treated being hollow, at least one rotating tool can be arranged so as to carry out compression from inside the part to be treated.

At least one rotating tool can be arranged so as to carry out compression from the outside of the part to be treated simultaneously and on the same surface as compression from the inside of the part to be treated.

A rotating tool may include vanes that can be folded down on the shank to reduce the diameter of the tool so that it can be inserted into tight spaces before deploying the vanes. By collapsible fins we mean fins that can be folded so as to be located near the stem in a collapsed or folded position. The tool then has a reduced external diameter, allowing access to areas of a part that are difficult to access with a non-flat tool. Once in position, the folding fins can then be deployed. The tool at this time has an external diameter substantially similar to that of a non-flat tool.

At least one rotating tool may be fitted with a conveyor device in order to move it relative to the part to be treated.

The support can be rotated.

The support and the rotating tools can be made to rotate in opposite directions.

A rotating tool may include fins arranged successively on its axis in the axial direction.

Another object of the invention is a cabin comprising the adjustment and prestressing system as described above, further provided with soundproofing means and means for suction and filtration of the air inside. inside the cabin.

Alternatively, the invention relates to an adjustment and prestressing system comprising a rotating tool and a support configured to hold a part to be treated, the system comprising a means for rotating the rotating tool as well as a means control, the rotary tool comprising at least two fins arranged on either side of a rod, each fin comprising balls and/or abrasive surfaces on at least one face, the rotary tool being arranged so that the balls and/or abrasive surfaces on their fins come into contact with the surface of the part to be treated during their rotation in order to adjust the surface and generate compression, the part to be treated being hollow, the at least one rotary tool is arranged so as to achieve compression from the inside of the part to be treated.

The invention also relates to an adjustment and prestressing method in which the surface of a part undergoes an adjustment step and a local compression step via an adjustment and prestressing system. prestressed comprising at least two rotary tools and a support configured to hold a part to be treated, the system comprising means for rotating the rotary tools as well as a control means, each rotary tool comprising at least two fins arranged on either side and on the other of a rod, each fin comprising balls and/or abrasive surfaces on at least one face, the rotating tools being arranged so that the balls and/or abrasive surfaces on their fins come into contact with the surface of the workpiece as they rotate in order to adjust the surface and generate compression, in which the rotating tools are rotated in a coordinated manner.

Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example and made with reference to the appended drawings in which:

- the figure illustrates a rotating tool of an adjustment and prestressing system according to the invention,

- the figure illustrates a variant of the rotary tool comprising several fins in succession,

- the figure illustrates an adjustment phase with a rotating tool,

- the figure illustrates an embodiment of an adjustment and prestressing system according to the invention,

- the figure illustrates an alternative embodiment of an adjustment and prestressing system according to the invention,

- the figure illustrates another embodiment of an adjustment and prestressing system according to the invention, and

- the figure illustrates a conveying device included in an adjustment and prestressing system according to the invention.

detailed description

The figure illustrates a rotating tool 1 comprising a rod 2, on which a strip 3 is fixed. The strip 3 is arranged so as to form fins on either side of the rod 2.

Strip 3 is impregnated with resin, to give it a certain rigidity while maintaining sufficient flexibility to deform during contact with the surface to be treated. It will be understood that in general, the fins of a rotating tool 1 are flexible so as to deform on contact with the part to be treated. Strip 3 is defined as comprising a first face and a second face opposite the first face.

A first part of the strip 3 extending from a first side of the rod 2 comprises, on its first face, at least two balls 4, in particular made of tungsten carbide or ceramic and two abrasive zones 5a, 5b covered with grains abrasives of different sizes.

A second part of the strip 3 extending from a second side of the rod 2 comprises, on its second face, at least two balls 4, in particular made of tungsten carbide and two abrasive zones 5a, 5b covered with abrasive grains of different sizes.

In the embodiment shown in the figure , the balls 4 are arranged so as to be further from the rod 2 than the abrasive zones 5a, 5b, on both sides of the rod 2. This embodiment is not exclusive, and other embodiments will be presented later in this description.

Likewise, on both sides of the rod 2, the abrasive zones 5b covered with abrasive grains of a first size are arranged so as to be further away from the rod 2 than the abrasive zones 5a covered with abrasive grains of a second size greater than the first size.

The arrangement of the balls 4 and the abrasive zones 5a, 5b is advantageously chosen so that, during use, the coarsest grains of abrasive come into contact with the material first, followed by the finest grains. which in turn precede the balls 4. This arrangement makes it possible to concomitantly remove the defect present on the surface to be adjusted, while generating an adequate surface condition, before the impact of the tungsten balls 4 allowing a setting in compression of the surface. In such a rotation mode, the tool rotates in only one direction, so that the faces of the strip 3 covered with grains and balls 4 come into contact with the surface.

It will be easily understood that other configurations of balls and/or abrasive zones can be used on a rotating tool without departing from the scope of the present invention. In other embodiments, not illustrated, a rotary tool 1 may comprise only fins provided with abrasive zones or only fins provided with tungsten carbide balls. Alternatively, the same tool 1 may include fins provided only with abrasive zones and fins provided only with tungsten carbide balls.

Likewise, all or part of the balls 4 and the abrasive zones 5a, 5b can be encapsulated so as not to be able to detach and become embedded in the surface to be treated. More generally, encapsulation can be achieved by applying a coating, notably a varnish or a resin.

In a particular embodiment of a rotating tool, several fins can be arranged one after the other on the same axis. The figure illustrates such an embodiment. It will be understood that the successive fins have a spacing that can be modified depending on the purpose of the tool. The fins can be spread apart to compress several distinct surfaces or the fins can be brought together to obtain maximized coverage of the treated surface. This last embodiment is particularly advantageous in the case of large surfaces to be treated for the treatment of which a single fin of great width could present mechanical resistance problems (in torsion, deformation or tearing).

The figure illustrates an adjustment phase during which abrasive grains come into contact with the surface of the part 6 to be treated during the rotation of the rotary tool 1.

The figures And illustrate a rotating tool 1 whose fins are perpendicular to the axis of rotation.

The figure illustrates an embodiment of an adjustment and prestressing system according to the invention. The system comprises at least two rotating tools 1 and at least one support for holding a part 6 to be treated in position. The adjustment and prestressing system also includes a means for rotating each rotary tool 1 and a control means. A means for rotating the support to hold a part 6 to be treated in position can also be provided. The rotation means and the control means are not illustrated in the figure . Each rotation means comprises for example an electric motor and a transmission mechanism (for example a clamp, or a reduction gear coupled to a clamp) to transmit the rotation of the motor to the tool or the support. The control means is for example an electronic module comprising at least one processor and a memory, and connected to the actuators (for example motors) of the system, so as to be able to control them.

Via the control means and the rotation means, the adjustment and prestressing system is able to rotate each rotary tool as well as possibly the support. The control means is capable of controlling the rotation means in a coordinated manner with each other, in particular simultaneously, or sequentially according to a predetermined scheduling (the corresponding processing sequence being stored in the memory of the processing module). order). The control parameters and possibly the activation order are stored in the control means. Advantageously, the rotating tools 1 and the support are driven by rotational movements in opposite directions.

Advantageously, the rotating tools 1, the number of which is for example between two and ten, or even between two and six, are arranged around the part 6 to be treated so that their axes of rotation are parallel to each other and parallel to the axis of rotation of the part 6 to be treated. In addition, the tools can be arranged at the same distance from part 6 and with the same spacing between them.

Such a configuration makes it possible to apply compression simultaneously in several zones, and depending on the size and geometry of the part to be treated, in several directions. This is particularly the case when the rotating tools are arranged at least partially around the part to be treated. This combination of application directions helps to reinforce the effect obtained. In addition, such a configuration with several rotating tools 1 may be necessary to treat the entire surface of the part 6 to be treated, particularly for larger parts. Such a configuration is particularly suitable for processing parts with simple geometry, such as parts with a constant section, in particular of the circular, elliptical, ovoid type or any other convex section and without angular points. This configuration allows, for this type of part, particularly rapid processing of the part, due to the potentially high number of rotating tools, acting simultaneously and continuously on the part.

Alternatively, each rotating tool can be associated with a conveyor device so as to be moved between several parts of the surface of the part 6 to be treated. A reduced number of rotating tools 1 can then carry out the compression of a part compared to processing by tools with a fixed position. In addition, such an embodiment makes it possible to process parts which do not have a surface profile of revolution (for example profiles with a square or prismatic section). Indeed, the rotating tools 1 can be moved around the part 6 to be treated while maintaining a constant distance from the part. Such an embodiment makes it possible to avoid rotating the part 6 to be treated.

It should be noted that the embodiment illustrated by and its variant involve a fairly complex realization of the adjustment and prestressing system from a mechanical point of view, in particular due to the rotation and/or conveying operations of the tools around the part to be treated. In return, this embodiment and its variant (as well as the other embodiments presented) confer a significant time saving on adjustment and prestressing operations.

In addition, as in the other embodiments, the coordinated control of all the rotating tools by the control means allows better control of the processing of the part 6 to be treated. Such coordinated control makes it possible in particular to avoid the same area being treated twice, which would have the effect of inappropriately increasing the local constraint (the pre-established processing sequence, stored in memory, can also be a sequence with a single pass of the roto-shot peening tool for each area of the part to be treated). Furthermore, processing times are then better controlled.

In an alternative embodiment, illustrated by the figure , the adjustment and prestressing system comprises rotating tools 1 arranged so that the axis of rotation of at least one of them is normal to the axis of rotation of the other rotating tools 1. Such configuration improves the coverage of rotating tools 1.

In a third embodiment, illustrated by the figure , the adjustment and prestressing system comprises at least one rotating tool arranged so as to carry out compression inside a part 6 to be treated. Depending on the size of the part 6 to be treated, at least one other rotating tool can be placed inside the part 6 to be treated, as illustrated in the figure .

Each tool can be moved in depth independently in the part 6 to be treated, according to the direction of its axis of rotation. Each tool can also be associated with a conveyor device so as to be moved in a plane normal to its axis of rotation and to apply compression to several parts of the internal surface of a part 6 to be treated. A part 6 thus treated can be, for example, a hollow shaft for a turbine. Remember that such a tree is generally painted on the internal side, and that compaction of this paint is then desirable.

The control means of the adjustment and prestressing system is designed so as to be able to control the depth movement means as well as, when applicable, the conveying device of each rotary tool 1. Just as in the other modes of implementation, the control means makes it possible to achieve coordinated control of the rotation means, the depth movement means and the conveying devices.

Such coordinated control makes it possible to adjust the rotation speed and the position of each tool, depending on their position relative to the part 6 to be treated and depending on their nature. Such coordinated management provides a lot of flexibility, and makes it possible to optimize the processing to be carried out while maintaining reduced processing time.

Such an embodiment is particularly advantageous for parts not having a circular section (for example, an elliptical section) for which rotation of the part to be treated does not allow a rotating tool 1 to reach the entire interior surface. of the part to be treated. The conveying system illustrated is not restrictive and other forms of movement of a rotating tool can be considered.

In a variant, two rotating tools 1 are arranged on either side of the surface of the part 6 to be treated so as to apply compression simultaneously from the inside and the outside of the part 6 to be treated. Here again, the combination of several compression directions makes it possible to amplify the effect obtained.

Alternatively, the adjustment and prestressing system according to the third embodiment comprises a rotating tool with fins that can be folded into or near the axis so as to reduce its bulk. Once the collapsible fins are folded, such a tool can then be inserted into a slot provided in a side wall of a hollow part. After insertion, the fins are unfolded and rotated to compress a surface of the part 6 to be treated from the inside. Here again, a second rotating tool can be positioned opposite the surface treated by the rotating tool with folding fins.

In the embodiment of the and some and for their variants described above, the adjustment and prestressing system comprises at least two rotating tools. However, the technology described here also relates to a system for adjusting or prestressing from the inside of a hollow part, this system comprising a single rotating tool. Thus, the present technology also relates to an adjustment or prestressing system comprising at least one rotating tool and a support configured to hold a part to be treated, the system comprising means for rotating the rotating tool, the tool rotary tool comprising at least two fins arranged on either side of a rod, each fin comprising balls and/or abrasive surfaces on at least one face, the part to be treated being hollow, the rotating tool being arranged so to carry out a compression or adjustment from inside the part to be treated.

Such a tool with folding fins can be produced by a combination of cams supporting the fins and an actuating means arranged in the axis of the rotating tool.

In the different embodiments, the adjustment and prestressing system can be integrated into a soundproof room or cabin so as to limit noise pollution linked to surface treatment. The cabin or room is equipped with more than one suction system and filters allowing the evacuation of air and pollution emitted in the cabin without releases harmful to the environment.

Claims (15)

Adjustment and prestressing system comprising at least two rotary tools (1) and a support configured to hold a part to be treated (6), the system comprising means for rotating the rotary tools as well as a control means, each rotary tool (1) comprising at least two fins arranged on either side of a rod (2), each fin comprising balls (4) and/or abrasive surfaces on at least one face, the rotary tools ( 1) being arranged so that the balls (4) and/or abrasive surfaces (5a,5b) on their fins come into contact with the surface of the part to be treated (6) during their rotation in order to adjust the surface and to generate compression, the control means being configured so as to control coordinated rotation of the rotating tools. Adjustment and prestressing system according to claim 1, in which a rotating tool comprises at least one fin provided with abrasive surfaces and at least one fin provided with balls. Adjustment and prestressing system according to any one of claims 1 or 2, wherein a rotating tool comprises at least one fin provided with both abrasive surfaces and balls. Adjustment and pretensioning system according to any one of claims 1 to 3, in which a fin is provided with an encapsulation layer in order to prevent balls (4) or particles from the abrasive surfaces (5a,5b ) to become detached. Adjustment and prestressing system according to any one of claims 1 to 4, in which at least one rotary tool (1) is arranged so that the direction of its rod (2) is perpendicular to the direction of the rod ( 2) at least one other rotating tool (1). Adjustment and prestressing system according to any one of claims 1 to 5, in which the part (6) to be treated arranged in the support extends from the support along a longitudinal axis, at least two rotating tools (1) then being arranged so that the direction of their rod (2) is parallel to the longitudinal axis of the part (6) to be treated. Adjustment and prestressing system according to any one of claims 1 to 6, in which the part to be treated (6) being hollow, at least one rotary tool (1) is arranged so as to carry out compression by inside the part to be treated (6). Adjustment and prestressing system according to claim 7, in which at least one rotary tool (1) is arranged so as to carry out compression from the outside of the part to be treated (6) simultaneously and on the same surface as the compression from inside the part to be treated (6). Adjustment and prestressing system according to any one of claims 7 or 8, in which a rotary tool (1) comprises wings which can be lowered on the rod (2), so as to reduce the diameter of the tool in order to be able to be introduced into tight spaces before deploying the fins. Adjustment and prestressing system according to any one of claims 1 to 9, in which at least one of the rotating tools (1) is provided with a conveyor device in order to move it relative to the part to be treated (6 ). Adjustment and prestressing system according to any one of claims 1 to 10, in which the support is driven by a rotational movement. Adjustment and prestressing system according to any one of claims 1 to 11, in which the support and the rotation tools (1) are animated by rotational movements in opposite directions. Adjustment and prestressing system according to any one of claims 1 to 12, in which a rotation tool (1) comprises fins arranged successively on its axis in the axial direction. Cabin comprising the adjustment and prestressing system according to any one of claims 1 to 13, further provided with soundproofing means and means for suction and filtration of the air inside the cabin . Adjustment and prestressing method in which the surface of a part undergoes an adjustment step and a local compression step via an adjustment and prestressing system comprising at least two rotating tools ( 1) and a support configured to hold a part to be treated (6), the system comprising means for rotating the rotary tools as well as a control means, each rotary tool (1) comprising at least two fins arranged on either side and on the other a rod (2), each fin comprising balls (4) and/or abrasive surfaces on at least one face, the rotating tools (1) being arranged so that the balls (4) and/or or abrasive surfaces (5a,5b) on their fins come into contact with the surface of the part to be treated (6) during their rotation in order to adjust the surface and generate compression, in which the rotating tools (1 ) are rotated in a coordinated manner.