METHOD FOR THERMAL SPRAY DEPOSITION OF A COATING ON A SURFACE AND APPARATUS

Abstract

Method of deposition of a coating on a surface of a workpiece, working with at least one deposition device, or torch, of Thermal Spray type, controlled by an associated motor. It is contemplated to perform the deposition step by configuring the torch so as to create two concurrent movements, of which a first movement along a linear path on the surface area to be coated; a second oscillation movement according to an axis of rotation coaxial with said advancement direction; this allows increasing the spray pattern of the thermal spray torch at each stroke resulting in a reduction of the relative movement speed of the torch itself.

Claims

1. A method for depositing a coating on a surface of a workpiece, the method working with at least one device, such as a Thermal Spray deposition torch, controlled by a robot; the method comprising carrying out the deposition step by configuring the torch so as to create two concurrent movements, of which: a. A first movement (M1) along the area of the surface to be coated; said first movement being carried out by the robot or equivalent system; b. A second movement (M2) of oscillation according to a rotation axis (AA) coaxial with said advancement direction; said second movement being carried out by a further associated motor.

2. The method according to claim 1, wherein said second movement prepares the oscillation of the torch head.

3. The method according to claim 1, wherein said second movement prepares the oscillation of only the nozzles of the torch head.

4. The method according to claim 1, wherein said second movement prepares the oscillation of both the full torch and of the nozzles.

5. The method according to claim 1, wherein said second movement is an oscillation of +/30, with respect to a plane perpendicular to the surface to be coated.

6. A torch for the deposition of surface coatings by thermal spray technologies, the torch mechanically associated with a movement apparatus and adapted to perform coatings (R) on a surface (S) of a workpiece through one or more nozzles dispensing the material; the torch comprising at least one motor mechanically associated with the head thereof; the motor being configured to impart, by an intermediate mechanism, an alternating oscillation of the torch head, according to an axis perpendicular to the direction of the nozzles, and thereby to the output of the filling material; the coating material dispensing nozzles are fixed with respect to the torch head.

7. A torch for the deposition of surface coatings by thermal spray technologies, the torch mechanically associated with a movement apparatus and adapted to perform coatings (R) on a surface (S) of a workpiece through one or more nozzles dispensing the material; the torch comprising at least one motor mechanically associated with said nozzles; the motor being configured to impart, by an intermediate mechanism, an alternating oscillation of said nozzles, according to an axis perpendicular to the output direction of the material from said nozzles; the torch remains fixed in position with respect to the motor.

8. (canceled)

9. A Thermal Spray deposition torch according to claim 1, wherein an arm/extension is provided between said motor and said torch which can be of different length depending on the application and on the workpiece to be worked; the tubes/cables necessary for the operation of the torch are contained within the extension.

10. The method according to claim 1, wherein said second movement is an oscillation of +/15, with respect to a plane perpendicular to the surface to be coated.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0038] This and other features will become more apparent from the following description of some of the configurations, illustrated purely by way of example in the accompanying drawings.

[0039] FIG. 1: shows a conventional Thermal Spray deposition torch, according to the prior art, with the denomination of the component parts of the apparatus,

[0040] FIG. 2: shows an example of application of the claimed invention, with oscillating system on a plasma torch for thermal spray; the example is not limiting, the system may be applied to other thermal spray technologies (APS, HVOF, Flamepray, Arcspray, etc.).

[0041] FIG. 3: shows the operational step of the torch embodying the method of the invention.

DESCRIPTION OF THE INVENTION

[0042] With particular reference to the figures, reference numeral 10 indicates a Thermal Spray torch comprising spray heads and nozzles 11 through which a flow F comes out which conveys coating material with filling R is made on surface S of the workpiece.

[0043] The torch 10 head is mechanically associated with a motor 20 able to create a rotation according to a longitudinal axis AA which will correspond, in operating conditions, to the linear advancement axis of the torch itself.

[0044] In the example, motor 20 is configured to impart a rotation (i.e. an oscillation) of +/15, however, this value is not binding for the requested protection and can be increased or reduced according to the requirements.

[0045] The torch oscillation allows increasing the spray pattern and thereby reduce the translation speed, this allows controlling the position with higher precision.

[0046] Motor 20 together with a mechanical motion transmission mechanism (not shown) constitutes an oscillating system which allows carrying out the operating step according to the invention.

[0047] Motor 20 is controlled by an electronic feedback system (not shown) which allows setting a speed and keeping it stable during use.

[0048] According to possible embodiments, the torch is adaptable to the different working conditions, since the oscillating system described and claimed herein may be used for both inner and outer coating torches.

[0049] To this end, the torch may be installed on an arm/extension, indicated with reference numeral 15 in FIG. 3, which can be of different length depending on the application and the workpiece to be processed.

[0050] In this case, all the tubes/cables necessary to the operation of the torch are contained within the metallic extension 15 of the oscillating arm to protect them from exposure to high temperatures.

[0051] The unit described above, namely motor 20, possible arm 15 and torch 10, is preferably installed at the end of an anthropomorphic robot 30, or a similar handling system and arranged so as to carry out the coating against the surface of the workpiece, orienting its nozzles toward said surface and allow the movement along the rectilinear direction M1, or in any case a direction that maintains a predetermined distance from surface S to be coated.

[0052] The thermal spray torch 10 for generating the flame used for the thermal coating is connected to a standard control system and the oscillating unit does not interfere with the thermal spray system.

[0053] In essence, the head of the thermal spray torch is designed to be installed on an oscillating support, where the oscillating support is motorized and allows a +/15 oscillation; a motor speed control system and one or more motion transmission mechanisms on the head and/or the nozzles are also provided, as said above.

[0054] In summary, with particular reference to the figures and to the description herein, the following is claimed: [0055] the method for depositing a coating on a surface S of a workpiece, the method working with at least one device 10, a Thermal Spray deposition torch; the method provides for carrying out the deposition step by configuring the torch so as to create two concurrent movements, of which: [0056] A first movement M1 along a linear path on the area of the surface to be coated; said first movement being carried out by the robot 30 or equivalent system; [0057] A second movement M2 making an oscillation according to a rotation axis (AA) coaxial with said advancement direction M1; said second movement M2 being carried out by a further associated motor 20. [0058] In an embodiment of the present invention, said second movement prepares the oscillation of the torch 10 head. [0059] In an embodiment of the present invention, said second movement prepares the oscillation of only the nozzles 11 of the torch head. [0060] In an embodiment of the present invention, said second movement prepares the oscillation of both the full torch and the nozzles. [0061] Said second movement is an oscillation of +/30, preferably +/15, with respect to a plane perpendicular to the surface to be coated. [0062] The Thermal Spray deposition torch is also claimed, mechanically associated with a movement apparatus and adapted to perform coatings on a surface of a workpiece through relative nozzles dispensing the material: [0063] wherein the torch comprises at least one motor mechanically associated with said head; the motor being configured to impart, by means of an intermediate mechanism, an alternating oscillation of the torch head, according to an axis perpendicular to the direction of the nozzles, and thereby to the output of the filling material; the coating material dispensing nozzles are fixed with respect to the torch head. [0064] Wherein the torch comprises at least one motor mechanically associated with said nozzles; the motor being configured to impart, by means of an intermediate mechanism, an alternating oscillation of said nozzles, according to an axis perpendicular to the dispensing direction of the material from said nozzles; the torch remains fixed in position with respect to the motor. [0065] Wherein the torch comprises at least one motor mechanically associated both with said head and with said nozzles; the motor being configured to impart, by means of an intermediate mechanism, an oscillation to both components, according to an axis perpendicular to the dispensing direction of the material from said nozzles. [0066] An arm/extension 15 is provided between said motor and said torch which can be of different length depending on the application and on the workpiece to be worked; the tubes/cables necessary for the operation of the torch are contained within extension 15.