Patent Application
20170305070
The present disclosure relates generally to a manufacturing system, and more particularly, to a manufacturing system implementing laser-curing of epoxied joints.
Welding is the process of joining two components (typically metals or thermoplastics) through the localized application of high heat. In some instances, the base materials of the components are melted when exposed to the heat, causing the components to fuse directly to each other. In other instances, the heat causes a filler material to be melted within a joint between the components. Upon cooling, the melted materials harden to form a solid connection. One common method of welding is known as Laser Beam Welding (LBW), wherein the heat used to melt the materials is generated by a laser. Although welding can be effective, the high temperatures required to melt the materials can cause undesired property changes and/or distortion within the materials.
An alternative method of joining two components involves the use of a heat-cured epoxy. In particular, an epoxy can be applied between two components to be joined. The components are then mechanically connected to each other (e.g., via rivets), and the resulting assembly is placed inside an oven and heated above a cure temperature of the epoxy. In some instances, the assembly must be held at the elevated temperature for a specified period of time before curing is complete. Although the cured joint can be used as an alternative to a fused joint, the conventional use of heat-cured epoxies can be time consuming, complex, and expensive.
The disclosed manufacturing system is directed to mitigating or overcoming one or more of the problems set forth above and/or other problems in the prior art.
One aspect of the present disclosure is directed to a manufacturing system. The manufacturing system may include at least one clamp configured to maintain a distance of separation between a first component and a second component for an epoxy provided therebetween. The manufacturing system may also include a laser, and a controller in communication with the laser. The controller may be configured to cause the laser to direct at least one light beam against one of the first and second components to heat the epoxy by conduction to a cure temperature.
Another aspect of the present disclosure is directed to a method of manufacture. The method may include providing a quantity of an epoxy in a space between a first component and a second component with an epoxy. The method may also include directing a light beam against at least one of the first and second components to heat the epoxy by conduction to a cure temperature.
Yet another aspect of the present disclosure is directed to an automotive body. The automotive body may include a first body panel having a first flange, and at least one of a second body panel and a frame having a second flange. The automotive body may also include a heat-cured epoxy sandwiched between the first and second flanges. The first and second flanges may be connected to each other by only the heat-cured epoxy.
The disclosure is generally directed to a manufacturing system that may reduce a time, complexity, and/or cost of joining two or more components to each other. In some embodiments, the manufacturing system may be used to join components of an automobile, for example body panels of a car. The system may utilize a laser heat source to cure an epoxy located between the components (e.g., between flanges of the components). Once the epoxy is cured, the components may be rigidly connected to each other at the flanges via only the epoxy. The heat provided by the laser heat source to cure the epoxy may be low enough to ensure that material properties of the components are substantially unaffected.
In the exemplary embodiment depicted in
Manufacturing system 10 may include multiple parts that cooperate to create joints 17 between the components (e.g., between first and second body panels 18 and 20) of automobile 12. These parts may include, among other things, an epoxy dispenser 26, one or more clamps 28, a laser 30, and a controller 32. As will be explained in more detail below, epoxy dispenser 26 may be manually and/or automatically operated to place a layer of epoxy 34 (shown only in
Epoxy 34 may be manually or automatically applied to the components of automobile 12 as either a liquid or a soft solid (e.g., a paste or a gel). For example, epoxy 34 may be painted on one or both of the components using dispenser 26, sprayed from dispenser 26 onto the components, squeezed out of dispenser 26 into the joint space between the components, or applied in some other manner. Epoxy 34 may be a heat-cured type of adhesive made from a thermosetting polymer, and curing of epoxy 34 may be completed more efficiently when a temperature of epoxy 34 is maintained at an elevated cure temperature for a specific period of time. According to some embodiments, the cure temperature is less than about ⅓ (e.g., within 10%) of a lowest melting temperature of the components being joined by epoxy 34, with the specific period of time being reduced for higher cure temperatures. For example, when the components being joined are fabricated from aluminum or an aluminum alloy having a melting temperature of about 450-700° C., the cure temperature of epoxy 34 may be about 150-233° C., and the specific period of time may be about 60 seconds (e.g., 45-65 seconds). By keeping the cure temperature less than about ⅓ of the melting temperature of the components being joined by epoxy 34, the likelihood of changing the material properties of the components during curing may be low.
Any type of clamp 28 known in the art may be used to hold the components of automobile 12 before, during, and/or after curing of epoxy 34. For example, clamp 28 may be a C-style clamp, a pipe clamp, a bar clamp, a spring clamp, a ratchet clamp, a cam clamp, a wheel clamp, or another type of clamp. Clamp 28 may be manually actuated or automatically actuated (e.g., by way of a motor in communication with controller 32), as desired.
Laser 30 may be configured to generate and direct one or more polarized light beams 36 toward joint 17. Laser 30 may include, for example, one or more of an Excimer laser, a Yb:tunstates laser, a CO2 laser, a Nd:YAG laser, a DPSS laser, or any other type of laser capable of heating epoxy 34 to its cure temperature. In the disclosed embodiment, laser 30 is configured to produce a light beam 36 having a circular or square cross-section, with a dimension (e.g., a diameter or width) that is less than an applied width of epoxy 34 within joint 17.
Controller 32 may embody a single processor or multiple processors that include a means for controlling an operation of manufacturing system 10. Numerous commercially available processors may perform the functions of controller 32. Controller 32 may include or be associated with a memory for storing data such as, for example, an operating condition; design limits; performance characteristics or specifications of epoxy 34, clamps 28, and laser 30; operational instructions; and corresponding quality parameters of joint 17. Various other known circuits may be associated with controller 32, including power supply circuitry, signal-conditioning circuitry, solenoid driver circuitry, communication circuitry, and other appropriate circuitry. Moreover, controller 32 may be capable of communicating with other components of manufacturing system 10 via either wired or wireless transmission.
Many different arrangements may be used to mount the different parts of manufacturing system 10. In the exemplary embodiment of
In some applications, multiple joints 17 may need to be created simultaneously within automobile 12. In these applications, one or more lasers 30 could be caused by controller 32 to create these joints 17. For example, a single laser 30 could be operated to create a single light beam 36, which is subsequently directed through a beam splitter 40. In this example, beam splitter 40 may split the single light beam 36 into any number of different light beams 36 that are each used to simultaneously create a different joint 17. It is contemplated that beam splitter 40 may be stationary (e.g., mounted to a fixed location within body station 14) or movable (e.g., mounted to laser 30, robotic arm 38, or a different arm or gantry mechanism). In another example, multiple lasers 30 mounted to the same or different robotic arms 38 may be operated to simultaneously create the different joints 17 using separate light beams 36.
In some embodiments, laser 30 may be operated by controller 32 to direct light beam(s) 36 to known locations where joint 17 should always be created. In these embodiments, placement of automobile 12 may be tightly controlled, such that the corresponding components are clamped together at the known location prior to activation of laser 30. In other embodiments, however, the location of joint 17 may need to be detected after automobile 12 is moved into body station 14, such that laser 30 can be appropriately aimed and controlled. In these embodiments, a locator 42 may be used to locate the intersection of the automobile components, such that joint 17 may be appropriately created. Locator 42 could be, for example, a camera configured to visually detect the joint location, an RFID reader configured to detect the presence of a corresponding tag placed at the joint location, a proximity sensor configured to interact with automobile 12 and/or fabrication platform 16, and/or another type of device known in the art. Signals indicative of the detected location may then be directed from locator 42 to controller 32 for further processing. Locator 42 could be stationary or mobile, and mounted together with laser 30 (e.g., on robotic arm 38) or mounted separately, as desired.
Light beam 36 may be directed against an outer surface (i.e., a surface not in contact with epoxy 34) of one of flanges 44, thereby heating epoxy 34 by way of conduction through the impinged flange 44. In some applications, an entire length of flanges 44 may not need to be joined. That is, epoxy 34 may be applied at spaced-apart intervals, and light beam 36 may be used to “skip-weld” flanges 44 to each other at the intervals. In these applications, light beam 36 may be directed to imping flange 44 at a location immediately adjacent clamp 28, and move away from clamp 28 to create a joint 17 having a maximum length L. In some embodiments, length L is about 70 mm.
Light beam 36 may be directed against the one of the abutting flanges 44 having a greater capacity to conduct heat into epoxy 34. In some applications, this may mean that light beam 36 is directed to impinge a thinner of the two flanges 44. In other applications, this may mean that light beam 36 is directed to impinge the flange 44 fabricated from a material having a greater coefficient of thermal conductivity. Other strategies may also be employed.
After clamps 28 are in place on flanges 44 of body panels 18 and 20, controller 32 may cause laser 30 to generate light beam 36 at the clamped area (Step 320). As describe above, only a single light beam 36 may need to impinge only an outer surface of one of flanges 44 in order to sufficiently heat epoxy 34 to the cure temperature. It is contemplated, however, that multiple light beams 36 could be simultaneously directed at both flanges 44 from opposing or alternating sides, if desired. Controller 32 may continue to cause laser 30 to heat a specific section of flange(s) 44 until controller 32 determines that the temperature of epoxy 34 within that section has been maintained above the cure temperature for at least the specified cure time (Step 330). When skip-welding is required, light beam 36 may begin proximal clamp 28 and be caused to move in a length direction of flanges 44 away from clamp 28 for the specified length L (Step 340). Thereafter, clamps 28 may be released (Step 350).
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed manufacturing system and related method. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed manufacturing system and related method. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
This application claims the benefit of U.S. Provisional Application No. 62/327,786, filed Apr. 26, 2016, the entirety of which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62327786 | Apr 2016 | US |
