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Instantaneous undeformed chip thickness (IUCT) plays a critical role in optimizing and monitoring of five-axis milling processes, as it determines machining precision and tool life by affecting cutting forces. Analytical and numerical methods have been widely used for IUCT calculation. However, these methods have some deficiencies, such as solving the unsolvable transcendental equations, modeling the complex cutting edge trajectory, and poor adaptability for five-axis milling. Therefore, a Boolean method which consists of subtraction and intersection operations is developed. First, the blank for the current cutting edge is obtained by the Boolean subtraction operation between the workpiece and the swept volume that produced by the front cutting edges. Second, the Boolean intersection operation is executed between the blank and the auxiliary edge entity (AEE) that corresponding to the tool edge. Then, the IUCT of each cutting edge or each cutting point can be deduced based on the Boolean result with the known blank geometry, tool geometry, tool path, and machining parameters. The method is verified by milling force experiments. It is an efficient, accurate, and general method because it does not need to establish complex mathematical or numerical models. The calculated IUCT will promote the optimizing and monitoring of five-axis milling processes.

The residual stresses (RS) generated during the thermal processing processes such as casting and heat treatment is one of the fundamental causes of irreversible deformation of diesel engine bodies (DEBs). However, previous studies only focused on the RS generated from casting or the effect of annealing heat treatment on the RS in castings unilaterally, and the analytical results were far from the actual conditions. Therefore, this paper proposes a comprehensive research method to consider the whole dynamic evolution of the casting from the RS generated by casting to the stress relief by heat treatment. Numerical simulation of DEBs casting process is carried out by PROCAST, and the results of casting RS obtained from the simulation are imported into ABAQUS, and then numerical simulation of annealing heat treatment is carried out for the DEB casting model with casting RS, so as to realize the analysis of dynamic evolution of RS from casting to heat treatment.

Camshaft is a key part of marine diesel engines. However, the large residual stresses resulting from the induction hardening to which the cams are submitted may lead to cracks on their contacting surfaces. These cracks have great influence in the service life of the shaft. In order to find the relationship between the induction hardening process parameters and the residual stress field, the process was simulated by the finite element method, and the SYSWELD and ANSYS software were used. The temperature distribution during hardening process and stress field of the camshaft after the process were obtained and analyzed. The thickness of the hardening layer was calculated. The simulation results were validated by residual stress measurement experiments and showed a good agreement with the practice. The method reported on the present paper provides an efficient way to analyze the camshaft induction hardening process and avoid the surface failure of the cams.

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.

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.

Helical groove is one of the key structures of end mills. Its grinding process is the hardest and most time-consuming in end mill machining. According to the practical groove-grinding process, a Boolean method to simulate the groove-grinding process is proposed in this paper. The groove model is obtained with the known wheel geometry by a sequence of Boolean operations. Accordingly, the wheel used to machine a desired groove is deduced with the similar method. Based on the Boolean operation results and principles of differential geometry, contact lines of the wheel and groove are illustrated and calculated to optimize the groove-grinding process. Wheel positions relative to the blank are described by a sequence of mathematical coordinates. Wheel profile expressions are built with the corresponding transformation matrixes including groove geometry transformation matrix, cutter tip transformation matrix, and start processing position transformation matrix. Some simulated examples are included to illustrate the presented method.

Clearance of end mills has great impact on the performance of milling, and therefore a high demand for its machining theory and process is put forward. Based on the analysis of practical machining process, enveloping theory, principles of spatial geometry are introduced to establish the clearances processing model, as well as considering the geometries, orientations, and locations of wheels used to machine the clearances with convex, eccentric, or elliptic shapes. Accordingly, limitations of wheel geometry and location to machine a desired clearance are discussed. A commercial computer aided design system with API function programming is used to visualize the machining process. The solid model is finally obtained.