Key Engineering Materials Vol. 522

Abstract: The application, which the intelligence is used in the fault diagnosis, is the main direction of research currently, especially in the fault diagnosis of large mechanical equipment. In order to improve hydraulic system failure diagnosis of high-speed deep drawing hydraulic press, reduce the efficiency and accuracy of difficulty diagnostic staff. By using rough sets theory combining neural network and the method of large NC hydraulic press, hydraulic system fault diagnosis of diagnosis. This paper established based on rough set - neural network fault diagnosis model, and the following hydraulic cushion hydraulic system as an example, the diagnosis in establishing the fault table based on the rough set theory to fault table attribute reduction and generating rules, will rule input to the BP neural network was trained learning. Get in neural network after the test data repository and simulation. Test results show that the method for the diagnosis of high-speed deep drawing hydraulic press hydraulic system fault is effective.

Abstract: This paper presents a manual moving and lifting worktable. This worktable consists of roof, base,cross frame, wheels, lifting device, wire driving two-way ratchet and parallelogram steering structure. It can do some action such as moving, turning and lifting through the manual operation for the application of warehouse, logistics, and indoor maintenance. The paper analyses the principle and structure of the worktable, especially on the design and work principle of two-way ratchet. The design is satisfied by built a real model.

Abstract: Coal gas accident is the main threat to the safety production in coal mine,it needs a safe and efficient drilling equipment to detection and drainage in the gas area.At present,the equipments detect and drainage in underground coal mines are mainly fission rigs,which move time-consuming, and the efficiency of drilling is low.This paper introduces a new kind of full hydraulic drill car used in coal,it includes the integral design of the car, the structure layout, the drilling arm and the main parts of design ideas.The new drill carriage adopts the caterpillar vehicle structures,full hydraulic pressure drives,it can automatically change the drill rod, prevent bit-stuck device,can freely passage in the narrow roadway,arrived at the reservation of the drilling position and carries on the omni-directional drilling,it can meets various mine construction requirements, and it has a broad market prospect.

Abstract: In this research, a simulation model of an animal Traumatic Brain Injury test platform is established using Solid Edge software. Applying the Biological Functions testing system and Matlab, performance analysis for the test platform was undertaken.

Abstract: In order to develop an efficient hip protector to protect the elderly's femur when he (or she) has a fall, the research on characteristics of sponge material is carried out. The buffer rate of material is defined, and the material absorption ability to the instant impact is measured in this paper. An experimental device which can simulate the force state of femur hit by instant impact when the elderly is falling down is developed and used to research the buffer rates of different types of sponge. According to the result, the soft material is effective to absorb small impact, while the harder material is useful for absorbing greater impact. Meanwhile, the buffer rate also largely depends on thickness of the material. Results show that in the same hardness material, the buffer rate of 30mm-thickness is apparently higher than that of 20mm and 10mm-thickness. And, when thickness of the material increases, the sensitivity of the buffer rate to the material hardness and to the instant impact acted on the material decreases. That is, the higher buffer rate could be obtained in a large range of instant impact and hardness of material. This conclusion is very useful for us to select suitable material to make hip protector or other sport protectors.

Abstract: The principle of modified gear was applied to silent chain transmission, and tooth profile equation of the involute sprocket was derived, then method of processing gear using imaginary rack cutter solved modification coefficient of involute sprocket. When Center distance of silent chain drive changed smaller, processing method of sprocket modification coefficient and range of modification coefficient values were analysed. The method by changing the modification coefficient of involute sprocket solves the problem that the chain links are increased or decreased in the actual application to be unable to meet the requirements of specific center distance, thus improve transmission performance of silent chain.

Abstract: According to the durability test results of pen cylinders, including failure modes and fatigue life data, life distribution of pen cylinder is studied. The parameters of Weibull distribution of pen cylinder are estimated by least square method. Using Weibull distribution test, the goodness-of-fit test of the pen cylinder life distribution is carried out. Results of goodness-of-fit test show fatigue life distribution of pen cylinder complies with Weibull distribution with two parameters.

Abstract: Based on the strong characteristics of comprehensiveness and practicality of the Mechatronics Control Engineering Class, a PBL based “One main line, Two links, Three practical points” teaching mode and methodology has been formed in 7-year exploring and practicing and has been applied in the teaching reform in mechatronics control engineering class at Beihang University. By implementing the method, excellent results have been gained and the teaching task has been accomplished well. It meets the requirement of cultivating innovative talents for the current social development and is worthwhile to be extended widely.

Abstract: The construction and the operating principle of the novel micro-angular vibration testbed (MAVT) are presented, the MAVT is designed to complete the angular performance testing for the micro sensor and parts such as MEMS-gyro, angular accelerometer. A systemic design procedure of the optimized flexure hinge and general voice coil actuator (VCA) to fine single-axis MAVT actuator are introduced for fast and precision actuation. A method for measuring frequency response function by means of a displacement sensor electric eddy current sensor is designed. To verify the performance of the designed MAVT, frequency response of the system are performed, the differential equation of the pull-tilting motion is established according to the Lagranges equation, the formula of the natural frequency is derived, and the model analysis of the MAVT is also carried out with the help of limited element analysis. The static stiffness experiments show that the angular stroke of the MAVT is 1° and preliminary tests performed on the closed-loop control system indicate that angular resolution of 1 can be achieved. Model experiments performed on the prototype of MAVT are presented and the theoretic result fits with the result of experiment (250Hz). For fast and precision actuation performances, design parameters are selected based on the dynamic model of VCA and flexure hinge, and design process is completed. The model results can be provided for the construction design of the MAVT. Conventional platforms of angular performance testing are bulky and costly. Analysis and experiments results indicate that the novel MAVT is an efficient platform to complete the angular performance testing for micro sensor and parts.

Abstract: With its technological development, the CNC embroidery machine rotational speed has increased dramatically. Consequent vibration and noise increase the disconnection rate in the embroidery process and affect the embroidery quality and production efficiency. To solve such problem, by analyzing the vibration causes and comparing the different characteristics of the Timoshenko beam and the Euler-Benouli simply supported beam, the current study indicated the limitation of the traditional vibration analysis method---the widely-used Euler-Bernouli simple beam theory, and constructed a vibration model based on the Timoshenko beam theory. Then a finite element model of the embroidery machine beam was built S and the corresponding experiment were done. Results from the constructed mechanical, mathematical model, and the ANSYS finite element model were compared. It has been verified that the constructed models are consistent with experiment results and that vibration models are constructed reasonably and feasibly. According to these models, the key parameters affecting the beam vibration are identified to work out more accurate and effective structure optimization design and prediction.