Grinding Head Research Articles

Study on Spindle System Static and Dynamic Characteristic in Grinding Head based on Finite Element Analysis

Study on Spindle System Static and Dynamic Characteristic in Grinding Head based on Finite Element Analysis

Design and Finite Element Analysis of Liquid Sliding Bearing and the Matching Spindle of High-Speed Roller Grinding Head

Through analyzing the design methods of liquid sliding bearing and the matching spindle of common roller grinding head, the design methods and ideas of liquid sliding bearing and the matching spindle of high-speed roller grinding head are put forward, and on these bases, a kind of liquid sliding bearing and the matching spindle of high-speed roller grinding head are designed. By means of finite element analysis of the bearing and the matching spindle respectively, it can be known that thermal property of the designed liquid sliding bearing can meet the working demands of high-speed roller grinding, and the designed spindle can meet the demands of strength and stiffness under the condition of high-speed grinding, thus, important reference materials for forming core technologies of high-speed roller grinding head are provided.

Testing of a CNC Control Abrasive Belt Grinding Machine Based on Ultrasonic Thick Measure for Nuclear Zirconium Alloy

A highly efficient precision grinding method was proposed for the development of Zr-4 alloy used in nuclear industry. The key techniques to develop this new grinding machine are presented in detail, including soft grinding wheel head, ultrasonic thickness measurement system. An automatic polishing and grinding system was built, which is based on ultrasonic thickness measurement technology. According to a lot of grinding experiments, reasonable, accurate and efficient Zr-4 Alloy grinding parameters was determined. The experiments show that when the line speed of belt is about 18 m/s; the workpiece feed rate is 1000mm/min; grinding head cylinder pressure is 0.12Mpa, the silicon carbide abrasive belt of P80 particle size can get 0.02mm grinding amount and achieve excellent grinding effect.

Design and Analysis of a Grinding Machine for Back Gouging of Outer Circumferential Weld

In order to improve the efficiency of back gouging of large thick wall vessels and the work condition, and to reduce labor intensity, this paper presents a large-power, compact-structure and easy-and-simple-handled grinding machine for back gouging of outer circumferential weld. This grinding machine consists of grinding head, manipulator and guide rail. Since a grinding electric spindle, in which a grinding spindle is directly connected to a motor, is used in grinding head, the structure of the drive system is greatly simplified. Firstly the grinding head can be controlled closer to weld for back gouging in a certain pose by the arm back, up down traverse of the arm, longitudinal and lateral movement of the manipulator. Secondly, radial force can be produced between grinding head and weld line by the arm telescopic and radial force can be kept constant by a flexible device. The manipulator is set up on the guide rail, so it can control the grinding head to accomplish back gouging of multiple welds. When the grinding head is set up on the different functional manipulator, it can accomplish back gouging of internal or outer circumferential-weld and straight-weld. As the power of grinding machine is large and the process of back gouging is high automation, the time of back gouging can be reduced by one fifth to one third and the efficiency of back gouging is significantly improved, and security and comfort of back gouging of weld can be increased as well.

Automatic Thermal Expansion Compensation of the Precise Grinding Machine AMB Spindle

Thermal expansion of the magnetic bearings in the process of precise grinding will lead to the posture drift of the grinding head, which can seriously affect the precision of the grinding. In this paper, the module of the relationship between temperature rise and the spindle posture is established, and the relationship between the controller’s five reference inputs and the spindle posture is ascertained. The controller’s five reference inputs are corrected according to the sample value of the temperatures in the system, so the inline adjustment of the grinding head posture and the automatic thermal expansion compensation of the system can be realized. Experiment proved that this algorithm could successfully compensate the thermal expansion of the AMB spindle.

Motive Simulation on the Grinding Head of Ceramic Polisher Based on Matlab

Taking the polisher as the example，this paper described the process of precision ceramic polisher and built up the mathematical model for polishing process and simulation．First, it contrasted to single–single-grit grinding head in the grinder for the general motion and planetary motion .Second, it contrasted to multi-single-grit grinding head in the grinder for the general motion and planetary motion. The simulated model provides the convenience of adjusting process parameters with Matlab for comparison of polishing effects，thus it is of avail to the determination of polishing parameters and the control of polishing quality．

Simulation and Experimental Research of Adaptive Control with Constant Pressure on Large-Scale Titanium Alloy Composite Plates

This paper brings a new method of adaptive control with constant pressure on large-scale surface grinding machine. The existing problem of uneven in the process of abrasive belt grinding on titanium alloy composite plates is solved effectively. And the grinding head and the belt follow the plate surface ups and downs effectively through contacting the workpiece with the constant pressure. Not only did ensure the grinding depth and the size of the titanium alloy plates, but also improved the surface processing quality. After experiment, the satisfactory control effect was obtained. The research results have some practical value on adaptive control theory and industrial practice.

Study on Heavy CNC Belt Grinding Technology of High Precision Controllable Pitch Propeller

A high-precision grinding method is presented to the marine controllable pitch propeller. Developed the four-axis simultaneous grinding system based on the abrasive belt grinding principle, and studied the key technologies of the grinder, such as the heavy-duty belt grinding head, the controllable pitch propeller grinding CNC programming software, etc. And on these bases, we have done the four-axis simultaneous heavy belt grinding test verification on the surface of the controllable pitch propeller blade with the grinder, providing a reference to determine the reasonable marine propeller belt grinding process parameters.

Experiment Research on Abrasive Belt Vibration Grinding Terminal Surface of Work Piece

In order to solve the problem of the alloy can not achieve the low surface roughness value in high-temperature, when it is grinded by abrasive disk, so that it can not meet the requirement of the craft. It uses abrasive belt grinding technology,adopts the method of fixed precise belt vibration grinding head on the CA6140 lathe and makes experiment of the impact on roughness of work piece surface from rotational speed of work piece , sand size of abrasive belt, horizontal amount of feed and process time. The result shows that the roughness value can achieve the requirement. It generalized the method of using abrasive belt grinding high- temperature alloy to make the roughness meet the requirement of craft, when guaranteed efficiency.

Creation of a planetary head for flat grinding of tough-to-machine materials

Reduced order of working out of the epicyclic head, allowing to realise a flat grinding, hard-tomachine materials, on an example of the trial sample for the machine tool 3Е711. Four-spindle an epicyclic grinding head the construction is developed for wheels in diameter of 80 mm.

The Grinding Head Design in Non-Circular Gear Grinding Teeth Based on the Planar Regions Interference Inspection

In the noncircular gear grinding methods using gear generator with form-grinding process, grinding headstock and workpiece may appear interference collision. The form-grinding radius selection problem based on the shaper has been discussed. Based on the designed grinding head, an effective form-grinding radius choose method and the head stock interference detection system has been established. This detection system is directly used in the grinder machining process; the solutions to the problems of both grinding head interference inspection and form-grinding radius selection in the grinding machine design process are introduced. In this paper, we briefly introduced the process for the design of inspection system and the relative algorithm of the method. Finally, The Program flow chart of the program design and implementation process was given and actual example of an outside triangle gear machining results is given, which validates the reliability of the system.

Study on the Fluid Magnetic Abrasive Polishing Technology

Fluid magnetic abrasive (FMA) is a new precision finishing process. It has the capability of processing free shape surfaces and complex cavities. Due to its strong adjustability and controllability, FMA could be regarded as the final process of machining which could greatly improve the surface quality of workpiece. The paper first introduces the component and machining mechanism of FMA, secondly it describes the model of the material removal in the process, thirdly it presents the devices of FMA polishing. At the end, a grinding head tool based machining mode is proposed for realizing the polishing of internal cavity.

The Research on New Grinding Head Used for Tool's Radius Offset of Spatial Conical Enveloping Surface Grinding

A basic method and characteristic of tool’s radial offset for conical enveloping surface, its structure and working theory as well as the most advanced planetary grinding head used in tool’s radial offset in the world are introduced. In order to improve the dynamic property of grinding head and method used in tool’s offset in existence, a new type of grinding head that can realize tool’s radial offset to big tool’s radial error was developed. It has the advantages of simpler structure, easier machining, lower cost, continuous and stable machining, and high efficiency, and is a new method of complex tool’s position offset.

A Hydraulic Elastic Feed Drive for Fine Grinding of Non-Circular Element

The hydraulic elastic feed drive utilizes a hydraulic bellows tube as the actuator. While pressure oil is etin, the bellows tube will axially expand and exert a pushing force on the vertical arm of the grinding frame. This pushing force will cause the deformation of the elastic arm and thus the displacement of the grinding head. Within the extent of elasticity, the displacement of the deformation is linearly proportional to the value of pressure. Thus, by controlling the pressure wave form, the desired trajectory of the grinding head can be obtained. A pressure valve is used to create the pressure waves. In this paper, the dynamic characteristics which significantly affect the position accuracy of the grinding head and thus the surface finish quality of the non-circular element are theoretically analyzed. A special experiment has been designed to test the performance of the hydraulic elastic feed drive, in which a constant force is applied to simulate the grinding force while the grinding head is keeping track of the contour of non-circular element. The experimental results demonstrate that the stiffness of the feed drive is large enough to maintain the position accuracy.

Development of Oscillation-Speed-Control-Type Sequential Grinding and Polishing Machine (2nd Report)

An oscillation-speed-control-type sequential grinding and polishing machine has been developed to achieve a site flatness better than 90nm per 25-mm square except for 2mm adjacent to the edge of a 12-inch silicon wafer. The machine allows a wafer to be polished after grinding without removal from the machine. This paper describes the creation of a grinding profile, a solution to the problem of flatness degradation, and the optimum polishing conditions to obtain good flatness. The moving path of the grinding wheel is accurately transferred to the ground wafer surface except its center portion, where the profile becomes concave due to high cutting path density of the grinding wheel. Good flatness was achieved with a simple inclination adjustment method that involves hanging a weight from the grinding head or using a very low infeed rate to decrease the grinding force. The ground wafer was polished at the optimum oscillation speed and a super-high flatness of less than 0.1µm over the entire surface was achieved. In addition, this result was roughly consistent with the simulation result.

砥石作業面のオン・ザ・マシン高速３‐Ｄ測定システム

In grinding, it is required to clarify the processing phenomenon and the process to be made intelligent. The acquisition of detailed tool information is necessary for the purposes. Consequently, not a small number of measurements for wheel working face has been reported. This measurement is expected to be high-speed and performed on the machine. However, there is no measuring system, which is suitable for these purposes. Therefore, this paper describes a high-speed 3-D measuring system for wheel working face on the machine. In this system, a sensing head similar to a laser displacement meter is used. The sensing head is attached to grinding head by two automatic stages. The wheel rotating at 30m/s peripheral speed is scanned by these stages. The scanning resolution is 3μm for X, Y, and Z respectively. This system essentially does not have any limitation for the measurement area. The results of measurements are studied experimentally. As a result, the data obtained by this system is in good agreement with that by a laser microscope.

A Basic Analysis of Inspecting Cylindrical Gear Accuracy on Machine Tool with a Touch-Trigger Probe.

This paper describes a basic analysis on accuracy inspection of involute cylindrical gears on a CNC type of gear grinding machine. The measurement principle of the present method consists of four steps which include: (1) feeding a touch-trigger probe fixed on the grinding head to a suitable position relative to the measured gear set on the table of the grinding machine; (2) rotating the table to contact the probe with the gear surface; (3) memorizing the rotation angle of the table at the contact position in NC apparatus of the grinding machine and then stopping the table movement; (4) repeating the measuring process for every measurement point in the gear surface. A simple and practical algorithm for computing the various gear errors, such as the errors of the tooth profile, the tooth trace, the pitch and the tooth thickness, based on the memorized data is established. The influence factors on measurement accuracy and their sensitivity coefficients are shown. This method is also applied for the other types of CNC gear cutting machine if the rotation angle of the table can be memorized.

An Experimental Investigation into Bearing-Induced Spindle Vibration

This paper describes experiments carried out to investigate the frequency response of a grinding machine tool spindle supported by preloaded angular-contact ball bearings. The experimental apparatus includes a loading device to simulate grinding head radial loads. The frequency spectra obtained show bands of frequencies associated with the ball passage frequency. The spectra also include bounce and rocking vibration modes of the assembly, where the supporting bearings act as non-linear springs. Good correlation of the dominant frequencies was obtained with the results of the theoretical models published elsewhere.

オンマシン計測による斜入射Ｘ線ミラーの超精密研削

This paper deals with a machining method for making a large non-axisymmetric aspheric surface with a high accuracy. An electric micrometer has been set near a grinding head on 5-axis control ultra-precision grinding machine for measuring the shape error of ground surface in conformity with the machine movement due to the cutter location data. A series of the measured shape errors corrects the former cutter location data automatically and the next grinding operation will be performed by the new cutter location data. A large CVD-SiC sample 110 by 510 mm has been ground into a toroidal surface of 0.75 μm in shape accuracy by the fifth grinding operation with the fourth correction of cutter location data. The machine has been also installed in a constant temperature room of ±0.5K in variation.

The Applications of Ultrasonic Waves to Mechanical Measurement : 1st Report, The Measurement of Displacement Using a 40kHz Ultrasonic Wave

This paper shows the methods and accuracy of a displacement measuring method which uses two 40kHz ultrasonic wave sensors as a transmitter and a receiver. The distance from the measuring probe to an object is measured by a phase difference which occurs between transmitted ultrasonic waves and received ones. This method has a special merit of performing the most accurate measurement with the simplest device. Accuracy of better than 1 um is obtained. At the end of this study, this separated probe method is applied to measure the displacement of a grinding head, and is compared with the electric micrometer. Experimental results show that this new method is almost as practical as conventional measuring methods, like the electric micrometer.