Mold measurement has always been a time-consuming and laborious task, and technicians need to constantly move the mold to achieve detection. Therefore, the birth of the law such as CMM measuring machine, let us say goodbye to this era.

 

Coordinate Measuring Machining (CMM) is a new type of high-efficiency precision measuring instrument developed in the 1960s. It is mainly used for detecting the length and width of workpieces, and in X, Y, Z. The geometry of the three-dimensional object is measured in the coordinate direction (Figure 1). The traditional CMM coordinate measuring machine is a fixed measuring device, which is relatively heavy and needs 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 carry a large number of heavy molds into the constant temperature quality control room of a fixed CMM coordinate measuring machine. Thus, the researchers developed a portable CMM measuring machine. The product is equipped with a telescopic rocker arm with joints. The structure is firm, movable and flexible. It can be quickly installed online, and it is easy to carry and accurate. It can accurately and repeatedly measure the geometry of objects, including geometric dimensions. Measuring functions such as geometrical tolerances, measuring accuracy up to 5μm.

 

In actual production, the user only needs to use a tripod or directly mount the measuring device on the machine tool for machining parts (with vacuum, magnetic base, etc.), and then guide the contact probe to the surface of the object to be tested. Scan the measurement, and then the 3D measurement process will begin to appear on the computer screen and all measurement data will be recorded and a comprehensive report will be created. Essentially, the device can create a three-dimensional "blueprint" of a part, or a "blueprint" of the machined part needed to make the part. Therefore, modern CMM can not only complete various complex measurements under computer control, but also can exchange information with CNC machine tools to realize the control of the machining process, and can also realize reverse engineering based on measurement data.

 

  The main function

 

Faru's CMM measuring equipment mainly includes Gage (portable CMM), 3D Portable Measuring Arm, Laser Scanner, Laser Tracker and CAM2 software series.

 

1. Digital processing of sheet metal parts

 

In sheet metal processing plants, technicians typically program the cutting patterns and then use these programmed programs for new laser cutting machines, water jet cutting machines, and automatic stamping machines. The entire conversion process includes scanning the contour of the model, transferring the digitized data file to the post processor in the .dxf format, and automatically converting the information into an NC cutting program through the post processor (Fig. 2). Generally, the entire programming work takes a full day. If a portable CMM coordinate measuring machine is used, it can be completed in just a few minutes. In addition, the portable CMM CMM can accurately measure a worn and damaged part, then create a 3D model and enter it into a CNC file.

 

2. Updates to old CAD drawings

 

After the sheet metal cutting program is created, an updated part drawing needs to be created using digitized data and AutoCAD software. However, in order to improve production capacity and production level, these samples are often modified and adjusted, and this information is not recorded in the software file. If you use the CMM coordinate measuring instrument, you can easily update the drawing with digital data to ensure the consistency of the drawing and the actual template.

 

Again, this method is also suitable for updating drawings of tools and fixtures. Because the drawings of these tools are modified several times before the workpieces are put into production, they have reached the optimal state. Therefore, measuring the data settings in the production by the CMM coordinate measuring machine and feeding back the data to the CAD system to update the drawings can not only save several hours of trial running time, but also avoid errors in the subsequent tool repair.

 

3. Mold inspection

 

Most CMM coordinate measuring machines can only collect measurement data of discrete points within a predetermined interval, while a portable CMM coordinate measuring machine can manually scan continuous contour surfaces. In the field of mold making, it is highly desirable to use such a measuring device with a rocker arm. The technician does not have to disassemble the mold first and then analyze where it needs to be improved. Simply measure the existing mold surface and then compare the surface contour generated by the measurement system with a computer-aided design software to compare it with a perfect theoretical image. If there is an inconsistency between the two comparison graphs, it indicates that the mold is partially defective. At this time, as long as the portable measuring device is used again, the relevant part of the surface of the mold is scanned and marked, and the mark is made for further rework modification.