The measurement and inspection of molds is easier
Mold measurement has always been a time-consuming and laborious affair, and technicians need to constantly move the mold to achieve inspection, so the birth of the FARO CMM measuring machine has put us goodbye to this era.
Coordinate Measuring Machining (CMM) is a new and efficient precision measuring instrument developed in the 60s of the 20th century, mainly used to detect the length and width of the workpiece, and measure the geometric dimensions of three-dimensional objects in the X, Y, Z coordinate direction (Figure 1). The traditional CMM coordinate measuring machine is a fixed measuring device, which is relatively heavy, and it is necessary to place the measured workpiece on the measuring machine for measurement. However, under modern industrial production conditions, especially in the mold manufacturing industry, it is very difficult to try to move a large number of heavy molds into the constant temperature quality control room of a fixed CMM coordinate measuring machine for measurement. As a result, FARO researchers developed a portable CMM measuring machine. The product is equipped with a telescopic rocker arm with joints, strong structure, movable, good flexibility, can achieve online rapid installation, and has the characteristics of easy to carry and reliable precision, can accurately and repeatedly measure the geometry of the object, including geometric dimensions, shape and position tolerances and other measurement functions, the measurement accuracy can reach up to 5μm.
In actual production, the user only needs to use a tripod or mount the measuring device directly on the machine tool where the part is machined (with vacuum, magnetic base, etc.) and then guide the contact probe to the surface of the measured object for scanning measurement, after which the 3D measurement process will be displayed on the computer screen, and all the measurement data will be recorded and a comprehensive report will be created. Essentially, the device creates a three-dimensional "blueprint" of a part, or a "blueprint" of the machined parts needed to manufacture that part. Therefore, modern CMM can not only complete various complex measurements under computer control, but also realize the control of the machining process by exchanging information with CNC machine tools, and can also realize reverse engineering according to the measurement data.
FARU's CMM measurement equipment mainly includes Gage (portable CMM), 3D Portable Measuring Arm (portable measuring arm), Laser Scanner (laser scanning head), Laser Tracker (laser tracker) and CAM2 software series.
1. Digital processing of plate metal samples
In the sheet metal processing shop, technicians often program the cutting templates and then use these programmed programs for the operation of new laser cutters, water jet cutters and automatic stamping machines. The entire conversion process includes scanning the model contours, transferring the digitized data file to the post processor in .dxf format, and automatically converting the information into an NC cutting program via the post processor (Figure 2). Usually the entire programming work takes a whole day, but if you use a portable CMM coordinate measuring machine, it can be completed in only a few minutes. In addition, the portable CMM coordinate measuring machine can accurately measure a worn and destroyed part, then create a three-dimensional model and import it into a CNC file.
2. Updates to vintage CAD drawings
After the sheet metal cutting program is created, an updated part drawing needs to be created using the digitized data and AutoCAD software. However, in order to improve production capacity and production level, enterprises often modify and adjust these templates, and this information is not recorded in software documents. If a CMM coordinate measuring instrument is used, it is easy to update the drawings with digital data, which can ensure the consistency of the drawings with the actual template.
The same applies to updating drawings of tools and fixtures. Because the drawings of these tools are also modified several times before the workpiece is put into production, to an optimal state. Therefore, measuring the data settings in production through the CMM coordinate measuring machine and feeding this data back to the CAD system to update the drawings not only saves several hours of commissioning time, but also avoids errors when the tool is returned for repair later.
3. Mold inspectionWhile most CMM machines can
only collect measurement data at discrete points at predetermined intervals, portable CMM machines can manually scan continuous contour surfaces. In the field of mold making, this measuring device with rocker arm is ideal. The technician does not have to disassemble the mold first and then analyze what needs improvement, but simply measure the existing mold surface, and then the surface profile generated by the measurement system is compared with a perfect theoretical figure with computer-aided design software, and if there is an inconsistency between the two comparison graphics, it indicates that the mold is partially defective. At this time, just use the portable measuring equipment again, scan and inspect the relevant parts of the mold surface, and make marks for further rework and modification.