Measure and record tool wear


Fig. 1 Tool wear formation process (example is a 6mm drill bit)
Figure 2 Construction of the measuring system: A digital camera equipped with a magnetic tripod is placed directly in front of the milling cutter of the milling machine
Figure 3 Abrascan wear measurement package at a glance, compact and practical
Figure 4 Turntable: wear scratch width VB=0.136mm
Figure 5 The diameter of the ball-end cutter is 3mm and the scratch width VB is 0.036mm
Fig. 6 Measurement accuracy: Scratches can be made with a measuring ruler with a scale of 0.1 mm. Measurement result D1=0.014 mm
Figure 7 The image of Abrascan can show that the horizontal axis represents the cutting distance of the tool, in meters, and the vertical axis represents the wear scratch width, VB, in millimeters. The three curves are cutters A, B, and C, respectively. Every cutter worker wants to increase the tool life. Graphs are mainly used to show the productivity of machining tools, and the depth of wear scar depth (VB) gradually increases as the service life increases. Producing the Profactor process shop in Steyr, Austria, from practical production has always used the method of measuring wear scratches on a stationary microscope in the “manufacturing process” field. The wear condition will be photographed and can be measured with the aid of graphics software. Since the microscope has a small usable working space, it is necessary to loosen the turntable or the full hard metal tool, so it is impossible to find out the width of worn scratches of an oversized or oversized tool such as a deep hole drill (Fig. 1). In the past, people mainly conducted inspections with a magnifier integrated with a measurement scale. Although the measurement flexibility can be improved, inconsistent measurement results may be caused due to operator differences. Similar results can show another kind of system under test: On the one hand, although the fixed measurement system has better economy, but the portable performance is poor; On the other hand, the simple mobile measurement system has low measurement accuracy and imaging quality. Poor, insufficient depth of measurement. If you need to record the formation process of wear frequently, and analyze the formation mechanism of wear, you need a completely new system. High-definition digital cameras (8 million pixels) are equipped with optical image stabilizers, newly developed microscope sights, and light sources for accessories. The universal joint magnetic tripod can be used as a mobile stand, and can be directly fixed on the machine (figure 2). If the user needs to optimize the process, the entire system can be placed in a portable container and equipped with the necessary battery backup, charger or cleaning device. Profactor's Josef Merkinger said: “The high quality of the picture, the measurement system, and the ease of operation of the evaluation software are a big advantage for us. And we asked repeatedly during the measurement process by users and tool makers if we needed to provide them with There is a software integrated measurement system package." Therefore, the wear measurement package "Abrascan" (Fig. 3) came into being. To date, technicians from the aerospace industry, tool manufacturing, and scientific instrumentation industries have begun to apply this system in cutting machining. After examining and optimizing the measurement system, they introduced the readers through this publication. The measurement process was very simple. The first user of this system was greatly encouraged: “All the adjustment parameters have been stored on the camera – sharp and sharp pictures can be taken within five minutes after opening the package.” The measurement procedure is as follows: Fix it on a magnetic tripod, turn on the camera and light source, fix it near the tool (±2mm), and use the auto focus function to quickly image. With a magnetic tripod it is also possible to measure directly on the milling machine without having to remove the tool from the bracket or spindle. The digital camera has a freely rotatable display that can be shot at any position. Shooting in C mode (user-defined mode) can store various experience values ​​in advance. For example, you can adjust the appropriate brightness, flash intensity, zoom, exposure index, or shutter speed. Therefore, users only need to open a digital camera to shoot at any time. Photo enthusiasts can of course fine-tune for different occasions. The stored images can be transferred to a laptop via a USB cable and evaluated using software. The sharp, sharp-edged picture on the surface uses a 6.5 x 6.5 mm measurement window and 8 million available pixels in a digital camera system to achieve resolutions of up to 2 μm per pixel. With a measuring depth of up to 0.4 mm, the system clearly shows the typical wear scratch width (20 to 200 μm VB) and the scratch width (10 to 50 μm VB) on the turntable. High-quality pictures can be directly applied to the machine tool to share the cost of purchasing the microscope. The Abrascan system clearly shows the formation of surface wear. However, this system is not suitable for measuring the absolute dimensions of the part because the distortion of the viewing plane leads to angular deviations and measurement errors. User-friendly measurement software The Abrascan evaluation software included in the wear measurement package measures distance (D), angle (A) and radius. Click the Distance icon to display the relevant dimensions in millimeters (Figure 6). More distance and angle measurements can also be displayed in separate pictures. Right-click to copy the relevant data and save it as an Excel spreadsheet file. This greatly simplifies the formation of wear scratch widths. Other auxiliary functions such as brightness, contrast, grayscale, etc. are also available. Because this system is based on Office software, users can quickly get started without having to participate in additional training. Exporting measured values ​​The stored measurement values ​​in the table calculation software can generate the wear formation process (Figure 7). With the Abrascan wear measuring system, extremely small wear marks can be identified and measured. Therefore, a measurable and graphical recording of the tool's optimization process can be performed. For further information please visit.