The present invention relates to ceramic matrix composites (CMCs), and more particularly, to means of machining CMCs.
CMCs are extremely hard and brittle and can therefore be hard to machine efficiently. Waterjet guided laser (i.e., laser microjet) technology is considered a promising manufacturing route for producing complex 3D holes in CMC parts. This technology works by transmitting a laser through a high-pressure water column to the surface of the part. Locating the waterjet nozzle to the part or fixture is accomplished by use of a retractable touch probe, off-set camera, or the water column itself. However, with particularly small holes and/or features, alignment via the touch probe and/or camera can be difficult due to physical interference between parts, especially those with nonplanar surfaces, and the nozzle head assembly. Thus, alternative means of alignment are desirable.
A device for forming a feature in a workpiece includes a waterjet guided laser device translatable relative to the workpiece. The waterjet guided laser device includes a head assembly having a nozzle comprising an aperture for ejecting a waterjet with an internal laser beam, and a camera system comprising a plurality of cameras disposed about the nozzle.
A method of forming a feature in a workpiece includes orienting a waterjet guided laser device about the workpiece by capturing a plurality of images of the workpiece with a corresponding plurality of cameras, generating a composite image from the plurality of images, and aligning a nozzle of the waterjet guided laser device to the workpiece based on the composite image. The method further includes ejecting a waterjet from an aperture of the nozzle, and impinging the waterjet against the workpiece causing a corresponding removal of material therefrom.
While the above-identified figures set forth one or more embodiments of the present disclosure, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features and components not specifically shown in the drawings.
This disclosure presents means for aligning a waterjet nozzle aperture with a workpiece using an in-line camera system. The camera system includes multiple cameras disposed about the waterjet nozzle. Such a system can generate a composite image surrounding the nozzle to help center the nozzle aperture, and thereby the water column, over a feature of the workpiece surface.
Head assembly 22 can include nozzle 20, camera system 32 collocated with nozzle 20, and touch probe 30. Nozzle 20 can include aperture 36 having an aperture diameter DI. Aperture 36 controls the diameter of ejected cylindrical waterjet 24, represented in
Camera system 32 can include at least one, and preferably, two to ten cameras 34 disposed about and proximate nozzle 20. In an exemplary embodiment, camera system 32 can include four to eight cameras 34. As shown in
Each camera 34 can be oriented in the direction of workpiece 26 for capturing an image of surface 28. Camera system 32 can further include processing device 40 in communication with each camera 34. Processing device 40 can include one or more field programmable gate arrays (FPGA), an application specific integrated circuits (ASIC), or microprocessors for performing image processing (e.g., cropping, scaling, etc.) as well as forming a composite image from the individual image of each camera 34. The composite image can be displayed on display 42 which can be associated with device 10. In some embodiments, each camera 34 can include a filter selective to the wavelength of laser beam 12 (
In operation of device 10, one or more features 44 (
The disclosed waterjet guided laser device can be used to form features in CMC components for use in aerospace, maritime, or industrial equipment, to name a few, non-limiting examples.
The following are non-exclusive descriptions of possible embodiments of the present invention.
A device for forming a feature in a workpiece includes a waterjet guided laser device translatable relative to the workpiece. The waterjet guided laser device includes a head assembly having a nozzle comprising an aperture for ejecting a waterjet with an internal laser beam, and a camera system comprising a plurality of cameras disposed about the nozzle.
The device of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
In the above device, the head assembly can further include a retractable touch probe.
In any of the above devices, the aperture can have a diameter ranging from 50 microns to 100 microns.
In any of the above devices, the diameter can be 70 microns.
In any of the above devices, the camera system can include two cameras to ten cameras.
In any of the above devices, the camera system can include four cameras to eight cameras.
In any of the above devices, the camera system can include four cameras.
In any of the above devices, each of the plurality of cameras can be configured to capture a corresponding plurality of images of a workpiece.
In any of the above devices, the camera system can further include a processing device for generating a composite image from the plurality of images.
Any of the above devices can further include a display for displaying the composite image.
A method of forming a feature in a workpiece includes orienting a waterjet guided laser device about the workpiece by capturing a plurality of images of the workpiece with a corresponding plurality of cameras, generating a composite image from the plurality of images, and aligning a nozzle of the waterjet guided laser device to the workpiece based on the composite image. The method further includes ejecting a waterjet from an aperture of the nozzle, and impinging the waterjet against the workpiece causing a corresponding removal of material therefrom.
The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional steps:
In the above method, each of the plurality of cameras can be disposed about the nozzle.
Any of the above methods can further include positioning the waterjet guided laser device such that the plurality of cameras are offset a distance from the workpiece.
In any of the above methods, the distance can range from 0.5 in to 1.5 in.
In any of the above methods, the aperture can have a diameter ranging from 50 microns to 100 microns.
In any of the above methods, the plurality of cameras can include two cameras to ten cameras.
In any of the above methods, the plurality of cameras can include four cameras to eight cameras.
Any of the above methods can further include displaying the composite image on a display.
In any of the above methods, a processing device can generate the composite image.
In any of the above methods, the step of impinging the waterjet against the workpiece can include impinging the waterjet against a partially formed feature in the workpiece.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.