At the same time, the evolution of modern quality concepts also reflects changes in the process planning of online inspection and the specific configuration of online inspection tools. On-line monitoring shows a trend of intelligence, while on-line inspection tools appear to be simplified and flexible. This is clearly recognized through the example of a crankshaft. At this time, in the grinding process of the production line, both the main journal and the connecting rod journal adopt high-speed and high-efficiency follow-up grinding technology, which can complete the entire grinding process after only one clamping. The use of a grinding wheel to implement a follow-up and tracking CNC grinding machine is a major breakthrough in crankshaft finishing technology. On the one hand, by adjusting the CNC control program, it can be flexibly applied to the processing of different types of workpieces, that is, it has good flexibility. And because the process of completely clamping the main journal and the connecting rod journal is performed once, the machining error is effectively reduced and the accuracy is improved.
In addition, because the CBN grinding wheel is used, the durability of the grinding wheel is greatly increased, and the productivity is increased. Especially by combining advanced random measurement technology and data processing system, the size and shape accuracy of the workpiece can be further improved and improved. Generally use the following two methods:
(1) With the data of the roundness of the journal of the workpiece measured by the Adcole1200 instrument installed in the production measurement room on the workshop site, after outputting the control system of the grinding machine, through correction and compensation, the journal manufacturing can be effectively improved quality.
(2) Use a hook-type external diameter active measuring instrument to complete the random measurement of the contour of the journal being ground, and according to the results of automatic detection, and then correct it through real-time data feedback to control the contour of the journal being processed.
Specifically, for example, the roundness of the journal will only be controlled within 4 to 4.5 μm when it is produced according to the original grinding process, and it is improved to less than 2 μm. Because of this, after adopting a flexible crankshaft processing method, the configuration of the testing equipment between the entire production line process has also changed significantly, showing a trend of intelligence, simplicity and flexibility. Originally, there were 3 different inspection tools in the entire grinding section, which corresponded to 3 grinding machines (1 main journal and 2 connecting rod journals). All of them are multi-parameter semi-automatic comprehensive inspection tools. ) The measuring method can not only measure the dimensional parameters, but also check the roundness, convexity, taper, runout and other shape and position tolerances. After adopting the new grinding technology, the accuracy, especially the shape and position tolerances, can basically be guaranteed by the process. In this situation, the new line configuration of the fixture changed from the original dynamic to static, all form and position tolerances are no longer detected, and only one section of the journal needs to be measured, instead of the original three . Therefore, the entire process is only equipped with a simple inspection tool consisting of multiple single-parameter handheld detection devices. Compared with the two, whether it is from the initial investment, subsequent maintenance costs, or occupation of the work area have been greatly reduced.
As for measures to deal with box-type parts, there are more and more cases where the coordinate measuring machine is used as an online detection device and is directly equipped on the workshop site. In fact, with the maturity of the technology of coordinate measuring machines used in the production site, more and more measuring machines are placed on the production site as an important means of online inspection between processes, and even connected to the production line to become a station, but Most domestic and foreign companies still adopt a simpler semi-open model. For example, the global coordinate measuring machine equipped with a newly built cylinder head cover production line in the same engine plant as the aforementioned engine was selected by Hexagon. A few years ago, an old line edge was a testing station with a multi-parameter integrated check fixture as its main body. Compared with the two, the former's advantages are mainly brought by the generalization and flexibility of the coordinate measuring machine is much higher than the multi-parameter comprehensive inspection fixture, so they are undoubtedly more suitable for the multi-variety mixed-line production mode of the contemporary automotive industry. .
At the same time, other distinctive flexible testing equipments also take advantage of their strong professionalism, high efficiency, and good adaptability, such as the flexible inspection tool based on the highly versatile FARO articulated arm measuring machine. It is very suitable for the measurement of box parts such as engine block, cylinder head and transmission case. As for the other type of fully-automatic flexible crankshaft detection equipment with a universal robot with a single-section measuring gauge as the main body, it only needs to support the workpiece to be measured on the bracket, and the inspection fixture can be easily and freely after programming. Single-section or multi-section inspection of the connecting rod journal and main journal of any variety of crankshafts (the diameter of the journal can be changed between 40 ~ 60mm). Because it is a static measurement, when the latter method is used, it is mainly used to test the convexity, which is often called the 'Barre line'.