BATTERY POWERED CNC LASER MARKER

A wireless laser marking tool for use in a CNC machine is disclosed. The wireless laser marking tool includes a tool housing with top and bottom opposing ends, a beam delivery system between the ends, and an opening at the bottom end; a tool adapter connected to the top end of the housing for adapting the device to the CNC machine; a laser diode disposed in the beam delivery system; beam-shaping optics disposed in the beam delivery system to focus light emitted from the laser diode through the opening; electronic circuitry disposed in the beam delivery system and in electrical communication with the laser diode; a wireless communication device disposed in the beam delivery system and in electrical communication with the electronic circuitry; and a power source disposed in the beam delivery system and electrically connected to the electronic circuitry.

FIELD OF THE INVENTION

The present invention relates generally to laser machining systems and manufacturing apparatuses or methods. More particularly, the present invention relates to a wireless laser marking tool for use in a Computer Numerical Control (CNC) machine.

BACKGROUND OF THE INVENTION

CNC machined parts are manufactured in a machining center using metal cutting tools, such as drills, end mills, taps, etc. If/when there is a need to mark/engrave (hereafter just “mark” for brevity) machined parts with information, e.g. manufacturing history and artistic designs or logos, the machined parts which need marking are then transferred to a separate or dedicated (standalone) marking machine, such as a laser marker, where a laser beam of sufficient power is directed upon the surface to cause a permanent change such as a burn or ablation where material is removed from the surface being irradiated. A laser marker generally requires at least the following components: a controller, a laser, and a means to generate the desired (geometrical) pattern by the laser in the part to be marked. Parts which need marking may be disposed on a motion system (e.g., a stage) while the laser beam is stationary, or a laser beam scanner may move the laser beam over the stationary part to be marked, or a combination thereof.

With use of a separate (standalone) laser marker for the marking operation, parts can be lost, misplaced, or mixed up when transferring between machines. Since each part must be precisely aligned with or positioned within the laser marker, an additional setup time is required, which increases overall manufacturing time and costs. As a conventional laser marker is a large machine, space is required on the shop floor for both machines (the CNC machine and the standalone laser marker).

Thus, wireless laser marking tools for use in a CNC machine are desired for improving laser marking of CNC machined parts, particularly as compared to having standalone machines operating separate functions.

SUMMARY OF THE INVENTION

Aspects of the present invention are directed to laser machining systems and manufacturing apparatuses or methods. More particularly, the present invention relates to a wireless laser marking tool for use in a CNC machine.

In accordance with one aspect of the present invention, a wireless laser marking tool for use in a CNC machine is disclosed. The wireless laser marking tool comprises a tool housing with top and bottom opposing ends, a beam delivery system between the ends, and an opening at the bottom end; a tool adapter connected to the top end of the housing for adapting the device to the CNC machine; a laser diode disposed in the beam delivery system; beam-shaping optics disposed in the beam delivery system to focus light emitted from the laser diode through the opening; electronic circuitry disposed in the beam delivery system and in electrical communication with the laser diode; a wireless communication device disposed in the beam delivery system and in electrical communication with the electronic circuitry; and a power source disposed in the beam delivery system and electrically connected to the electronic circuitry.

DETAILED DESCRIPTION OF INVENTION

Aspects of the invention are described herein with reference to exemplary wireless laser marking tool for use in a CNC machine. It will be understood by one of ordinary skill in the art that the exemplary tools described herein are not limited for use with a particular CNC machine, but may be applicable to other known similar devices.

The terms “workpiece” and “parts” (e.g. machined parts) as described herein and throughout the specification may encompass a variety of components formed (by a CNC machine) from a block of raw material, including but not limited to steel, aluminum, Inconel, titanium, Chrome-Molybdenum-Vanadium (CMV). Non-limiting examples of machined parts include a turbine, motor shaft, splines, etc. Likewise, the terms “information” and “pattern(s)” as described herein and throughout the specification may encompass a variety of data which may be useful for traceability of machined parts or required for a serialization process. However, laser marking is not limited to functional purposes (e.g. a QR code for providing date of manufacture, material bath, machinist, engineer, etc.), and may be additionally or optionally used for aesthetic marking, including but not limited to, artistic designs such as logos, text, images, layout patterns, etc. Still further, the term “marking” encompasses2D cutouts, which could be used to make 3D structures, used as templates, or other applications. It should also be understood that laser marking is not limited to certain industries, which may include high value, high security industries such as aerospace and healthcare.

Referring now toFIG.1, an exemplary system comprising a wireless laser marking tool and a CNC machine is depicted. In this system100, the CNC machine comprises a CNC tool changer carousel308(seeFIG.3A) and spindle310. A laser marking tool200is combined with the CNC machine300, thereby improving the capabilities of the CNC machine300and/or eliminating the need for a separate laser marking machine. Particularly, as will be discussed further below, the laser marker tool200is integrated into the CNC machine300by mounting the tool200in a standard CNC tool holder302(seeFIG.3B). In this way, the integrated laser marking tool utilizes the CNC machine300to provide the precise motions needed for laser marking. In operation, synchronization and/or coordination between the laser firing of the laser marking tool200and the motion of the CNC machine300is required. Additionally, or optionally, battery management and other tasks may be required. Thus, as will be discussed further below, communication between the laser marking tool200and the CNC machine300is necessary, and this communication may be performed wirelessly or remotely.

Turning now toFIGS.2and3A-3B, an exemplary wireless laser marking tool for use in a CNC machine is illustrated. In general, the wireless laser marking tool200includes a tool housing202, a laser diode204disposed within the housing202, electronic circuitry206in electrical communication with the laser diode204, a wireless communication device208in electrical communication with the electronic circuitry206, and a power source210(e.g. a battery) electrically connected to the electronic circuitry206. The tool housing202comprises a top end202aand a bottom end202bopposite the top end202a. Between the two ends is a beam delivery system212, wherein the laser diode204, electronic circuitry206, wireless communication device208, and power source210may be disposed. Also disposed in the beam delivery system212is beam-shaping optics222(seeFIG.6) configured to focus light emitted from the laser diode204(e.g. laser beam path224) through an opening214at the bottom end202bof the tool housing202. Additionally, or optionally, the bottom end202bof housing202comprises an optical tube or cover232and/or an optical shield or mount234for protecting at least the laser diode204housed within. Still further, the wireless marking tool200may include one or more of a diode cap and a diode heat sink220for dissipating heat generated by the laser204. In an exemplary embodiment, the wireless laser marking tool200is adapted to mark in gray scale.

As illustrated inFIGS.1,2and3A-3B, in order to facilitate integration of the wireless laser marking tool200with the CNC machine300, a tool adapter216(seeFIG.2) is connected to the top end202aof the housing202for adapting the laser marking tool200to the CNC machine300. The tool adapter216is configured to engage with one or more components of CNC machine300, such as the tool holder302, tool carousel308, and/or spindle310. In an exemplary embodiment, the tool adapter216is integrally formed with the housing202, such that for example, the tool adapter216extends from the top end202aof the tool housing202. Alternatively, the tool adapter216is a component separate from the housing202, and may be attached or connected to the housing202(e.g. the top end202aof the housing202) by known attachment mechanisms (e.g. snap fit, adhesives, etc.). The tool holder302may comprise an interchangeable machine taper304and/or an interchangeable pull stud306for connecting the laser marking tool200to the CNC machine300. The machine taper304and/or pull stud306may facilitate connection of the laser marking tool200with a CNC tool changer carousel308(FIG.3A) and spindle310(FIG.1). The CNC tool changer carousel308may comprise an automatic tool changer which include a series of standard tool holders disposed relative to each other at predetermined intervals along a circumference of tool changer carousel308. Thus, as the tool changer rotates in response to command from a controller, having wired connections is undesirable, particularly when the individual tool holders spin or rotate at high speeds. In one non-limiting example, the machine taper304may comprise a spindle taper for mounting in the CNC machine300. In this way, the wireless laser marking tool200is self-contained within the CNC machine300. In an exemplary embodiment, the wireless laser marking tool200can be stored in the tool carousel308of the CNC machine300and can thus be used or called upon by the CNC machine300without interruption or requiring additional fixturing or setup or moving time (necessary when using a separate laser marker machine). Additionally, or optionally, the integration of the wireless laser marking tool200with the CNC machine300includes a security feature, wherein the machined parts to be marked or engraved cannot be removed from the CNC machine300until after the laser marking operation. Finally, one skilled in the art would understand that the type, shape, size, and construction of the exemplary tool holder302are not limited to the illustrated holders302.

Referring now toFIGS.3B,4A-4B and5, specific details of the laser operation is disclosed. As shown inFIGS.4A-4B, exemplary electronic circuitry in electrical communication with the laser diode (FIG.3B) is disclosed. The electronic circuitry206may include a printed circuit board218comprising a top layer218a, bottom layer218b, an inner layer (a GND plane, for example)218c, and another inner layer (a power plane, for example)218d. The laser marking tool200also includes a wireless communication device208(FIG.3B) for facilitating coordination and/or communication between the laser marking tool200and a host or remote control device. In general, to facilitate wireless communication, the wireless laser marking tool200uses at least one of Bluetooth®, WiFi, infrared (IR), and near field communication (NFC) technology. Wireless communication would be more convenient than wired communication because the wired option would require modifications to the CNC machinery, including the CNC tool changer carousel308and spindle310. Furthermore, wireless communication allows for the remote enablement or disablement of the laser marking tool200or a component thereof.

In an exemplary embodiment, the wireless communication device208provides file transfer and/or synchronization information for the laser marking of a workpiece. Optionally, the wireless laser marking tool200is adapted to receive a removable data storage device (e.g. SD card) for data transfer. In a non-limiting example, the synchronization information is required when the wireless laser marking tool200is in synchronization with the CNC motion, such that the CNC machine300provides motion drive to the laser marking tool200. In a non-limiting example, synchronization may further be facilitated by an embedded motion sensor in the CNC machine300for synchronization. In particular, the laser marking tool200may comprise a Raster scan by the CNC machine300, with synchronization of each raster line by an inertial sensor and a gyro sensor that senses spindle310motion. Accordingly, the wireless laser marking tool200is adapted to encode functions in spindle motion of the CNC machine300. An exemplary encoded function comprises a safety interlock, such that the laser204is enabled only if a predetermined rotation per minute (RPM) is detected. In another exemplary embodiment, where wireless communication between the laser marking tool200and the remote or host control device is disabled or otherwise inoperable, thereby making synchronization between the laser marking tool200and the CNC machine300not possible, the wireless marking tool200uses a Vector scan by the CNC machine300with defocusing (Z motion) for marking a workpiece.

Importantly, the wireless laser marking tool200may have a laser diode204powered by a battery210, which is preferable over a wired or corded laser because this wired or corded option would require modifications to the CNC tool changer carousel308and spindle310. In an exemplary embodiment, the laser diode204may comprise a semiconductor laser. For example, the semiconductor laser is a continuous wave laser diode204having a wavelength of 390-470 nm and a power output of 1 W-5 W. Exemplary multi-watt blue semiconductor lasers204may include Metal Can® PLPT9 450LB_E Blue Laser Diode In TO-9 Package, as designed by Osram Opto Semiconductors GmbH of Regensburg, Germany. Additionally, or optionally, the laser204may comprise a Q-switched, diode-pumped solid-state (DPSS) laser. In one non-limiting example, the DPSS laser has the following characteristics, such as a wavelength of 1064 nm, a pulse energy (or power output) in a range between 10-5000 mW, a pulse duration in a range between 0.1-100 ns, and a pulse repetition rate in a range between 0.1-100 kHz. Additionally, or optionally, the wireless marking tool200includes one or more of a diode cap and a diode heat sink220for dissipating heat generated by the laser204.

In an exemplary embodiment, as shown inFIG.5, the battery-operated laser204is sufficiently powerful to mark or engrave metals to form high resolution functional and/or aesthetic patterns. Further, the battery210is of sufficient energy and power capacity and density, such that the battery-operated laser204may be housed in a small enough package so it can be installed in a standard CNC tool holder302for laser marking. In one non-limiting example, as shown inFIG.8, which shows a battery longevity test as assessed based on QR code pattern260marked by a 5-W blue (˜450 nm) laser diode, which draws ˜13 W of power at rated output laser power. A typical Ø18 mm×65 mm (L) Li-ion rechargeable battery cell (type18650) can have approximately 10 Whr usable capacity. So, using 2 such battery cells210to power the laser204should provide at least 1 hour laser of marking time, which is shown to be sufficient to support multiple use cycles of a laser marking tool200configured for forming a laser mark of a 23 mm×23 mm QR code with approximately 50% marked area (requires laser ‘ON’ duration for approximately 9 minutes). In an exemplary embodiment, battery210comprises a Li-ion battery cell having approximately 10 Whr capacity, such as Panasonic 18650 Li-ion 3180 mAh battery, as designed by Panasonic Energy Co. Ltd. of Japan.

To facilitate further multiple use cycles of the laser marking tool200, the battery210may be removable, such as for facilitating battery replacement. Additionally, or optionally, the battery210is rechargeable, and the wireless laser marking tool200comprises a charging port1250(FIG.9) for the battery210and/or means for wirelessly charging the battery210. Notably, the rechargeable battery210may be charged while the laser marking tool200is still attached to the CNC machine300. Additionally, or optionally, the wireless laser marking tool200comprises built-in battery management. In an exemplary embodiment, the built-in battery management includes at least one of battery level information, a sleep mode, and a switching device. Further, laser marking tool200may comprise a sensor for determining if the tool200is mounted the CNC machine300, such that if the tool200is not mounted in the CNC machine300, the tool200is powered off, and when the tool200is mounted in the CNC machine300, the tool200is powered on. In this way, battery life may be extended or improved.

Turning now toFIGS.6-7, an exemplary beam-shaping optics222is disclosed. The beam-shaping optics222is configured to focus light emitted from the laser diode204through the opening214at the bottom end202bof the tool housing202(seeFIG.2). In an exemplary embodiment, the laser beam path224passes through a collimation lens226, a cylindrical lens228for slow axis beam expansion, and focus lens230. For example, this design of beam-shaping optics222may be configured to obtain a focused laser spot on a workpiece of marking in the range of 5 μm to 200 μm. More particularly, this design of beam-shaping optics222may be configured to realize a focused laser spot of approximately 100 μm by 100 μm (FIG.7). Exemplary focus lens230may include SPX114AR.14 Fused Silica Plano-Convex Lens, as designed by Newport Corporation of Irvine, California. In an exemplary embodiment, the bottom end202bof housing202comprises an optical tube or cover232and/or an optical shield or mount234for protecting the laser diode204, the collimation lens226, the cylindrical lens228, and the focus lens230all housed within.

Referring toFIG.9, another embodiment of a laser marking tool for use in a CNC machine is illustrated. The components of this embodiment, such as laser marking tool1200, generally correspond to the components of laser marking tool200, as described above. The wireless laser marking tool1200includes a tool housing1202, a laser diode1204disposed within the housing1202, electronic circuitry1206in electrical communication with the laser diode1204, and a power source1210(e.g. a battery) electrically connected to the electronic circuitry1206. Also disposed in the housing1202is beam-shaping optics1222configured to focus light emitted from the laser diode1204. Also, the laser marking tool1200comprises an optical tube or cover, such as protective nozzle1232, for protecting at least the laser diode1204housed within. Still further, in order to facilitate integration of the wireless laser marking tool1200with the CNC machine300, the CNC machine300may comprise an interchangeable machine taper1304for connecting the laser marking tool1200to the CNC machine300, or components thereof, e.g. CNC tool changer carousel308(FIG.3A) and spindle310(FIG.1). To facilitate further multiple use cycles of the laser marking tool1200, the battery1210is rechargeable, and the wireless laser marking tool1200comprises a charging port1250(FIG.9) for the battery1210and/or means for wirelessly charging the battery1210.