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A high performance composite grinding wheel with brazed diamond sheets was developed for rail grinding. The rotation stress formula of the composite grinding wheel is deduced and analyzed, and the cutting off effect of the brazing sheet on the resin in the composite grinding wheel is analyzed. The finite element simulation analysis of the rotation performance of the composite grinding wheel is carried out when the brazing sheet is in the middle of the grinding wheel or one end of the brazing sheet is flush with the grinding end of the grinding wheel. The corresponding composite grinding wheel is made to carry on the rotation test, which is compared with the simulation analysis results. The results show that for the O260-size rail grinding composite grinding wheel, when using 15 mm wide and 55 mm long brazing sheets, the optimal placement angle is 55°, followed by 60° and 45°. The analysis of the noise detection results of the rotary testing machine shows that the resonance speed of the rail grinding wheel is between 4600–4800 rpm, and the rotary noise of the composite grinding wheel with brazing sheet is lower than that of the resin grinding wheel.

Applying complex groove with variable helical angle, rake angle, core radius or groove width along tool axis is an essential way to improve the cutting performance of solid end mills. However, the usage of complex groove is limited due to the lack of an effective way to calculate wheel path for its machining, because the previous envelope theory or trial-and-error method that used for simple constant groove can no longer be used for complex groove. In this paper, a general model is established to calculate the wheel path for complex groove machining based on a mathematical optimization model, which have three constraints and one objective. First, the complex groove is defined by four curves, namely the edge curve, rake curve, core curve and flank curve, so that the variable helical angle, rake angle, core radius and groove width can be expressed by mathematical formulas. Second, the grinding wheel path is expressed as a series of its position vectors, including three location parameters and three posture parameters. Then, these vectors are calculated by searching the minimum machining error of groove width with three constraints: contact constraint to meet the rake and core radius requirements, groove width constraint to prevent the overcut with the adjacent edge and non-interfere constraint to prohibit the interfere with the current edge. Finally, the accuracy and efficiency of the model are validated by five experiments with different designed complex grooves.

One of the major limitations of micro-milling applications in industries is its fast tool wear, which leads to low machining precision and efficiency. An accurate force model is fundamental for optimization micro-milling processes and minimize the tool wear. However, a generic model with tool runout and wear effect has not yet been established, which limits its practical application under varied working conditions. In this paper, a new idea is introduced by applying the spatial analytic geometry (SAG) method, under this framework the micro-milling force model is established based on the analysis of the geometrical relationship among the cutting edge positions, pre-processed workpiece morphology, and cutting force directions considering tool runout and wear effect. In this model, the tool runout is identified exclusively by only one parameter, namely the distance away from the center that perpendicular to the feed direction, so that it could be calibrated conveniently by calculating the ratio of resultant forces corresponding to different cutting edges. The tool wear–induced force is then modeled as increment of force coefficients to the original model. Therefore, the new force model with considering tool wear has the same form as the fresh tool. Finally, the accuracy and efficiency of the model are validated by experiments under varied working conditions.

The excessive residual stresses caused by heat treatment and grinding processes is one of the main challenges for Cam manufacturing, because they will lead to delayed cracks and reduce the fatigue life of Cam. Experimental studies are one of the essential ways to keep residual stresses at a reasonable value. Thus, orthogonal and single-factor experiments are carried out to explore the effect of heat treatment and grinding processes on the residual stresses of the Cam. The heat treatment processes include quenching temperature, tempering temperature, and tempering holding time. The grinding process includes grinding speed and feed speed. Besides, the superimposed residual stresses produced by heat treatment and grinding processes are analyzed. The results show that the heat treatment and grinding processes produce compressive residual stresses. The heat treatment process combined with the grinding process increases the superimposed residual stress. In addition, the critical factor for the distribution of the final stresses on the Cam surface is the grinding process, and the grinding speed plays the most important role. Therefore, in order to optimize the Cam machining processes to control the residual stresses, the optimization sequence is grinding speed, quenching power, and tempering temperature. The processes to obtain the least stress are as follows: 128 kW of quenching power, 200 °C of tempering temperature and 8 h of tempering time.

The unequal distribution of residual stress caused by incorrect machining processes will probably distort the machined connecting rods of the diesel engines. Thus, the influence of the machining processes on the residual stress and distortion of the rod need to be studied. Firstly, the finite element model is established based on the geometry of the connecting rod. Based on the life and death unit method, the influence of material removal on the residual stress of the connecting rod is discussed. Secondly, an orthogonal test is designed. The variables of the test include the quenching temperature, tempering temperature, cooling speed and the sequence of the machining processes. The deformation of the connecting rod is analyzed and then predicted based on the generalized regression neural network. The results show that the minimum distortion is achieved when the quenching temperature is 860 °C, the tempering temperature is 620 °C, the cooling speed is 50 °C h−1, and the machining sequence is “drilling the small end hole-milling, the upper planes-sawing, the connecting rod-turning, and the big end hole”. The priority of the influence of the processes on the deformation of the connecting rod is ranked as follows: cooling speed, quenching temperature, tempering temperature, and process sequence. The tensile residual stress is produced inside the connecting rod by machining processes. The generalized regression neural network predicts the connecting rod deformation accurately and the average error is 8.1%.

As an important transmission component of diesel engines, the connecting rod has to meet a very high processing accuracy. However, as an elongated part, the connecting rod has a weak rigidity, and the unevenness of the cutting force and the clamping force during the machining processes will lead to the deformation of the connecting rod. In previous researches, cutting and clamping are always studied separately, and their interactions are neglected. In this paper, the finite element simulation method is used to analyze the deformation of the connecting rod. Based on the Deform-3D software, the article builds a connecting rod milling finite element simulation model and predicts the residual stress of the connecting rod milling simulation and the formation of milling chips. The residual stress of the simulation is compared with the residual stress of the experimental measurement and the simulation chip is compared with the actual chip to verify the accuracy of the simulation model, which provides a theoretical basis for the model construction of the next simulation study. Based on the Deform-3D software, simulation studies the influence of different milling parameters on the deformation of the connecting rods. And optimize the link milling process parameters. Based on ANSYS software, the effect of superposition of cutting force and clamping force on machining deformation of the connecting rod was simulated and analyzed. The resultant milling force should not be greater than 734N. This method makes up for the defects that cutting and clamping are studied separately and their interactions are neglected.

A groove is a key component of the structure of end mills, drills, and other integrated cutting tools. Machining a groove is one of the most difficult, time-consuming, and costly manufacturing process; therefore, for the sake of reduction of the machining cost and meeting the environmental regulations, the modeling of a machined groove with known wheel geometry and position is necessary for cutting tool manufacture. In order to reveal the process more clear and precise, the envelope theory and numerical methods are used. First, the basic calculation procedure for groove section points is built using a meshing equation. Accordingly, four universal problems for the simulation of groove manufacturing process are analyzed by four typical examples. Namely, the wheel side surface may interfere the machined tool edge and lead to an incorrect simulation; the wheel revolution surface may overcut the machined tool edge and produce fake points that would disturb the results; the tip point might not be precise enough; and the groove section points might be distributed unevenly and result in an imprecise groove section. The conditions to solve these problems are established by mathematical formulas and calculated by numerical methods. In addition, an integral procedure is built to simulate the machined groove with correct, precise, and even distribution points. Finally, groove simulation software is developed using MATLAB GUI, and the results are verified.

Searching for and adjusting to the appropriate wheel positions for designed grooves are among the key issues in the manufacturing of the end mill, drill and other integral cutting tools. Along with the increasing requirements of product categories and quality, a large number of non-traditional and customized grooves continuously appear. However, as multivariable, nonlinear and multiple target problems, it is difficult to obtain the desired wheel position. Therefore, we introduce an intelligent method to search for the optimum wheel position for the designed groove with the known wheel geometry. According to practice, the basic parameters of the groove and wheel geometries are introduced, and the problems studied in this paper are explained. As a foundation, a robust algorithm is built to predict machined grooves with a series of equal distribution points and three parameters: the rake angle, core radius and groove width. The influence that the wheel positions have on groove geometries is then analyzed. Then, an objective function considering different machining requirements is built, and the optimum wheel positions are searched for while the function is solved. Furthermore, an enhanced niche particle swarm optimization (NPSO) algorithm is developed to solve the problem. Finally, 6 experiments are carried out to verify and analyze the algorithm. The results show that the algorithm can effectively find the desired wheel positions according to different machining precision requirements.

With good stiffness, the helical groove with variable-core radius has been widely used for end mills, drills and other integral cutting tools. However, ground by five-axis grinder, its machining process is high cost and time consuming. Thus, this paper reports a graphical analysis method to obtain the structure parameters and geometric shapes of variable-core grooves with the known wheel geometry and position before the practical machining. The wheel movement during the machining process is firstly decomposed into three simple motions and modeled as a translation matrix. Then, a family of wheel surfaces is calculated and the groove cross section line is deduced by splitting the surfaces with a cross section plane. Accordingly, the normal section line of the groove is expressed by a series of scattered points, which are the intersections of the normal section plane and the helical curves generated by the points on the groove cross section line which moves along the wheel trajectory. All the mathematic models are programed by Matlab and verified by experiment. Finally, the key parameters of the variable-core groove, including the rake angle, groove width on the cross and normal sections and the departure distance between the cross and normal groove section lines, are analyzed from the tool bit to the hilt.

The hard turning process has been widely used in the field of hard material precision machining because of its high efficiency, low processing residual stress, and low environmental pollution. Due to its undesirably processing quality, it is still not a substitute for traditional grinding, so many studies have reported that the process has been optimized. However, there has been little research on the geometry optimization of hard cutting tools, which have a great influence on the traditional machining process. In this paper, two tools with different rake face shapes are designed. The finite element analysis method is used to compare their performance with a conventional plane tool while turning hardened steel. The results show that the cutting performance of the designed tool T1 and T2 (chip morphology, cutting force, and cutting temperature) and the quality of the machined surface are improved compared with the tool. The cutting force decreased by 12.72% and 14.74%, the cutting temperature decreased by 7.56% and 9.01%, respectively, and the surface residual stress decreased by 26.56% and 28.66%.

For shafts with a large ratio of length to diameter, the existing measurement method mainly uses a contact coordinate machine. But machining errors have a strong influence on the offline measurement results, and the accumulation errors of the measurement system also make the measurement datum difficult to identify. For this reason, a new on-machine measuring method is proposed based on the spatial analytical geometry theory to achieve the measurement of the shape and position tolerance of shafts. Through the method, the measurement system combines the line laser measuring instrument and the laser displacement sensor together. Then, the ideal central axis of the workpieces can be obtained and serve as a datum. Finally, the on-machine non-contact measurement of large-size shafts with geometric errors is realized with high measurement accuracy (

Groove is one of the key structures of end mills. Some of them could be machined by standard grinding wheels (1A1 or 1V1 type), some others must design new wheel profiles. Based on the enveloping and analytic geometry theories, a novel algorithm was proposed to calculate the wheel profiles for special groove machining. The machining process was analyzed, the contact line principles were discussed, and the calculation procedure was detailed. In addition, the algorithm was implemented on a personal computer by using the MATLAB programming language. Therefore, the desired wheel profile could be computed automatically with four input parameters, namely, the groove lead, the wheel axial vector, the point coordinates on the wheel axis, and the discrete points on the groove profile (or groove profile expression). The proposed algorithm and the corresponding program were finally verified by three different examples. The results demonstrated good agreements with the practical wheel profiles.