Optimization of the precision gear grinding operation based on integrated information system

In accordance with the principles of hierarchical management, a comprehensive two-level management system is presented for the development and manufacturing of products for the stages of pre-production (the upper level of the management hierarchy) and for the actual production stage (the lower level of the management hierarchy). At the stage of pre-production, the gear grinding operation design on the “MAAG” type machines was carried out. For this purpose, a technique for optimizing the gear grinding parameters for a two dish-wheel rolling scheme has been developed, a mathematical optimization model containing an objective function with restrictions imposed on it has been created. The objective function is the gear grinding machine time, which depends on the operation parameters (gear grinding stock allowance, cutting modes, grinding wheel specification, part material) and the design features of the gears being ground (module, diameter, number of teeth, radius of curvature of the involutes). The article shows that at the stage of pre-production, the gear grinding optimization is a method of operation design. At the stage of actual production, a closed-loop automatic control system with feedback on the deviation of the adjustable value (gear grinding power) automatically supports the numerical power values that were found at the operation design stage, taking into account ensuring defect-free high-performance gear grinding (minimum number of working strokes and maximum longitudinal feeds). At this stage, i.e. when a robust longitudinal feed automatic control system is operating, the optimization carried out at the previous stage (pre-production) sets the functioning algorithm for the adaptive system with corresponding control algorithm. Thus, at the production stage (when the gear grinding machine is running), the operation optimization is a control method. Therefore, it is shown that with two-level control, the gear grinding operation optimization performs a dual function. On the one hand, it is a design method (at the pre-production stage), and on the other – a management method (at the actual production stage). With this approach, i.e. with the integration of production and its preparation based on a single two-level management, the efficiency of a single integrated design and production automation system is significantly higher due to general (unified) optimization, rather than partial one.

Deworming the Grinder for Successful Extrication of a Mangled Hand: A Case Report and Review of Literature

Grinding machine injuries are known to cause severe mutilating injuries of the upper limb. In some cases, the machinery equipment may still be attached to the limb when the patient reaches the hospital. In treating these injuries, the patient’s hemodynamic status should be the first priority of resuscitation. Following this and whenever possible, a reversal of the grinding mechanism should be done to free the limb as this would allow assessment of the extent of zone-of-injury prior to starting the surgical procedure. We report a case of a 28-year-old male who sustained a mangled hand injury that was successfully extricated from an industrial grinding machine, thereby allowing preservation of precious length of the limb during surgery. This case highlights the importance of adhering to safety precautions at the workplace to reduce the risk of potential occupational hazards when dealing with machinery equipment.

Feasibility of Optical Flow Field Measurements of the Coolant in a Grinding Machine

For industrial grinding processes, the workpiece cooling by metalworking fluids, which strongly influences the workpiece surface layer quality, is not yet fully understood. This leads to high efforts for the empirical determination of suitable cooling parameters, increasing the part manufacturing costs. To close the knowledge gap, a measurement method for the metalworking fluid flow field near the grinding wheel is desired. However, the varying curved surfaces of the liquid phase result in unpredictable light deflections and reflections, which impede optical flow measurements. In order to investigate the yet unknown optical measurement capabilities achievable under these conditions, shadowgraphy in combination with a pattern correlation technique and particle image velocimetry (PIV) are applied in a grinding machine. The results show that particle image velocimetry enables flow field measurements inside the laminar metalworking fluid jet, whereby the shadowgraph imaging velocimetry complements these measurements since it is in particular suitable for regions with spray-like flow regimes. As a conclusion, optical flow field measurements of the metalworking fluid flow in a running grinding machine are shown to be feasible.

Trends and development prospects of manual pneumatic grinding machines

В работе представлен анализ результатов эволюции параметров ручных пневматических шлифовальных машин на протяжении значительного интервала времени. Показаны достижения ведущих мировых производителей и выбраны три основных параметра, характеризующие возможности шлифовальных машин. Выявлены тенденции изменения удельной мощности и удельного расхода машин. Проведен сравнительный анализ перспектив развития машин с ротационным и турбинным приводом. Рассмотрена проблема совместной работы режущего инструмента и шлифовальной машины. Выявлена недостаточная быстроходность ручных пневматических шлифовальных машин с ротационным типом привода. Сделан вывод о большей перспективности применения многоступенчатых турбин в качестве привода шлифовальных машин. Представлен анализ компоновочных схем машин с турбинным приводом мировых производителей. Обоснована новая высокоэффективная конструктивная схема радиальных многоступенчатых турбин для привода пневматических шлифовальных машин. Показаны преимущества предложенной схемы, определены пути преодоления технологических барьеров при ее реализации. The paper suggests the results of analysis the parameters evolution of manual pneumatic grinding machines for a long time. The achievements of the world's leading manufacturers are shown and three main parameters that define the performance of grinding machines are selected. Trends in the specific power and specific air consumption of the machines are opened. An analysis of the development prospects for rotary and turbine machines is carried out. The problem of common action of a cutting tool and a grinding machine is considered. The insufficient speed of rotary manual pneumatic grinding machines is shown. It is determined that multi-stage turbines are most preferable for grinding machines. The design analysis of turbine machines of world manufacturers is presented. A new high-efficiency design of radial multi-stage turbines for driving pneumatic grinding machines is founded. The advantages of the new design are shown. The ways of overcoming technological challenges in the new design implementation are determined.

Design of a compact grinding machine

The availability and cost of tools are among concerns to the public and industries as key operation device used either for commercial or maintenance purposes such precision grinders or polishing machines are usually expensive. Assorted grinding tools in the market differ in terms of cost, required user proficiency levels and have different tool designs that can lead to limitations of flatness of ground surface and significant vibrations with prolonged use. The aim of this study is to develop a design compact grinder that is able to perform precise grinding and polishing while being cost efficient. Both functionality and ergonomic aspects were taken into consideration with market standards derived from datasheets. An initial design of the grinding machine was made using SolidWorks CAD software. A prototype was subsequently constructed and tested by using typical metallurgical sample preparation process with test parameters of grade of grinding paper and usage of lubricant. Microscopic image of ground specimens showed improvement in the quality of grinding with emery paper grades from coarse to fine grits with lubricant during the grinding process. Moreover, the designed compact grinding machine showed better surface finish when compared to using a typical angle grinder on aluminium sample.

Static Strength Analysis of Meat Grinder Frame

Meat is one of the agricultural commodities needed to meet protein needs, because meat contains high quality protein, which is able to contribute complete essential amino acids. The purpose of this paper is to design, analyze the static strength of the frame based on theoretical calculations and simulations on solidwork 2018 software. This machine consists of a frame, reservoir, grinding shaft, transmission, and electric motor. The results of the design obtained a Meat Grinding Machine with Length: 610 mm, Width: 500 mm and Height: 750 mm. The material used is 2024-O Alloy with a modulus of elasticity of 72,400 N/mm2. The load force obtained is 576.32 N. And the value from the analysis is the displacement value of 0.174 mm and for theoretical calculations, the displacement value is 0.176 mm. So, the value of the percentage error is 1.176%. For the von Mises value of 68,970 MPa, and for calculations based on the theory, the von Mises value is 52,499 MPa. So, the value of the error percentage is 0.238%. And for the value of the safety factor obtained a value of 1,087, and for calculations based on the theory, the value of the safety factor is 1.428. So, the value of the error percentage is 0.313%.

Research on Self-Aligning Flanges Based on Piezoelectric Actuators Applied to Precision Grinding Machines

Laser fusion research requires a large number of high-precision large-diameter aspherical components. To improve the grinding efficiency in the component production process, the manual operation time during the grinding process needs to be reduced. The grinding process requires the installation of the dressed grinding wheel onto the grinding machine spindle, and the off-line dressing results in installation errors during the loading and unloading process, which requires more time for manual alignment. To achieve self-aligning, the circumferential contour of the grinding wheel was first restored by the reversal method, then noise reduction and circle fitting were performed to obtain the eccentricity value and eccentricity position between the flange and the spindle, and finally, the flange was adjusted finely by three piezoelectric actuators installed inside the flange to reduce the eccentricity. Three repetitive experiments were conducted to verify that the self-aligning flange can reduce the eccentricity value by retracting the piezoelectric actuators so that the proper alignment between the flange and the spindle could meet the requirements; the average eccentricity value of the three experiments decreased by 74%, which greatly improved the efficiency of the grinding wheel alignment.

Process Related Characteristic-Based Topography Evaluation of Wear Conditions On Grinding Wheels

Non-productive auxiliary processes affect the single part and small badge production of milling tools. The key production process grinding is inevitably linked to the auxiliary conditioning process. The time demand of those process steps decreases the overall productivity of the manufacturing process. However, today the machine operator decides on conditioning cycles individually by the use of experience. Until today, there is no objective data based approach available that supports the initiation of these conditioning processes or the adaption of the grinding process itself in order to improve its process efficiency. For this purpose, a process related topography evaluation method of the grinding wheel surface is developed within this study. For the measurement an optical method based on laser triangulation is used. The measurement system is implemented into a common tool grinding machine tool. In addition, characteristic topography values are defined that show the wear conditions of the grinding tool. Moreover, the data is summarized in a database of wear conditions. The developed measurement method can save grinding and dressing tool resources, process times and minimizes scrap parts. In addition, an adaptation of the process and a targeted launch of auxiliary processes can be enabled. The novel characteristic-based topography measurement creates the opportunity to enhance the tool life of the grinding wheels up to 30 % without losing productivity.