Braking Solution for a Hydraulically Driven Linear Pallet Changer Mechanism

2014 ◽  
Vol 657 ◽  
pp. 485-489
Author(s):  
Lucian Mihăilă ◽  
Gheorghe Stan
Keyword(s):  
Medium Size ◽  
Kinematic Parameters ◽  
Two Stage ◽  
High Productivity ◽  
Counter Pressure ◽  
Pressure Limitation ◽  
Automatic Tool Changer ◽  
Hydraulic Cylinders ◽  
Automatic Tool ◽  
Set Up

The use of machining centres is predominant in the case of small and medium size batch manufacturing, their advantages being materialised in high productivity. The productivity is owed, mainly, to the small auxiliary times consumed with the tool and material change, times which are served by the automatic tool changer system and the automatic pallet changer. The purpose of this article researches aims to determine the kinematic parameters of an hydraulically driven linear pallet changer in two cases (when the deceleration is carried out through a throttle and when the deceleration is made through a new solution). Thus, an experimental set-up, which matches an hydraulically driven linear pallet changer, was designed and built. The experiments aimed toward using a classic braking method of hydraulic cylinders and a new two-stage braking with counter-pressure limitation.

Application of Tree Graph Method for Reducing the Total Time of Tool Changing in Milling and Boring Machine Tools

2013 ◽  
Vol 371 ◽  
pp. 431-435 ◽  
Author(s):  
Claudiu Obreja ◽  
Gheorghe Stan ◽  
Lucian Adrian Mihaila ◽  
Marius Pascu
Keyword(s):  
Machine Tools ◽  
Design Method ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Tree Graph ◽  
Cnc Machine ◽  
High Productivity ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up

With a view of increasing the productivity on CNC machine tools one of the main solution is to reduce, as much as possible, the auxiliary time consumed with the set-up and replacement of the tools and work pieces engaged in the machining process. Reducing the total time of the tool changing process by the automatic tool changer system can be also achieved through minimizing the number of movements needed for the actual exchange of the tool, from the tool magazine to the machine spindle (the optimization of the tool changing sequences). This paper presents a new design method based on the tree-graph theory. We consider an existing automatic tool changing system, mounted on the milling and boring machining centre, and by applying the new method we obtain all the possible configurations to minimize the tool changing sequence of the automatic tool changer system. By making use of the method proposed we obtain the tool changing sequences with minimum necessary movements needed to exchange the tool. Reconfiguring an existing machine tool provided with an automatic tool changer system by making use of the proposed method leads to obtaining the smallest changing time and thus high productivity.

Reliability Analysis and Improvement of ATCs of CNC Lathes

2010 ◽  
Vol 37-38 ◽  
pp. 939-943 ◽  
Author(s):  
Yi Qiang Wang ◽  
Xiao Jun Wang ◽  
Shun Ming Hua
Keyword(s):  
Failure Analysis ◽  
Block Diagram ◽  
Numerical Control ◽  
Coding System ◽  
Failure Data ◽  
Cnc Lathe ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up ◽  
Field Failure

An automatic tool changer (ATC) is one of the most important subsystems of a computerized numerical control (CNC) lathe. The field failure analysis is very important to improve the reliability of the ATC. The structure and mechanism of an ATC is briefly introduced. Its brief reliability block diagram is set up. With this understanding, through the collection of the field failure data, a coding system to code failure data is devised and a failure analysis database of CNC lathes is accrued. The failure mode and cause are analyzed to indicate the weak subsystem of the ATC. Some suggestions on improving the reliability have been proposed.

Transmission Ratio Optimization of Electric Driven Palletizing Mechanism

2013 ◽  
Vol 371 ◽  
pp. 421-425
Author(s):  
Lucian Adrian Mihaila ◽  
Gheorghe Stan ◽  
Marian Funaru ◽  
Dragoș Andrioaia
Keyword(s):  
Equilibrium Equation ◽  
Transmission Ratio ◽  
Motor Shaft ◽  
Maximum Acceleration ◽  
Positioning Accuracy ◽  
High Productivity ◽  
Functional Parameters ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Ratio Optimization

One of the main objectives in obtaining high productivity on machining centers is the reduction of auxiliary times consumed with the tool and workpiece change. In the case of workpiece change the auxiliary time is reduced by adopting the use of an automatic pallet changer system and implicitly of pallets, while in the case of tool change this time is reduced using an automatic tool changer system. The optimization of the constructive and functional parameters of palletizing systems, in the purpose of decreasing auxiliary times, implies increased speed and accelerations, inertia reduction, an optimum transmission ratio, component mechanisms coupled movements, increasing the positioning accuracy of the pallet on the machine table. This paper presents the methodology of transmission ratio optimization of an electric driven pallet changer mechanism, the main purpose is to obtain the maximum acceleration. In order to find the maximum acceleration of the electric driven pallet changing mechanism considered, and thus minimizing the total changing time, we use the equilibrium equation of the moments reduced to the motor shaft. Following the proposed methodology we obtain the maximum acceleration of the considered pallet changer mechanism. Also we issue some constructive indications for future designing of electric driven pallet changer mechanisms.

Material Handling Mechanisms Used in Flexible Manufacturing Systems

2012 ◽  
Vol 245 ◽  
pp. 197-202 ◽  
Author(s):  
Lucian Adrian Mihaila
Keyword(s):  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Material Handling ◽  
Machining Process ◽  
High Productivity ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
The Times ◽  
Small Tool

In small and medium batch series manufacturing the small tool and workpiece changing time is one of the main objectives to follow in obtaining high productivity. These auxiliary times are defined as the times consumed with preparing and changing the next tool or workpiece to follow the machining process, times that usually overlap the machining process. For this purpose machining centres are equipped with an automatic tool changer system and an automatic pallet changer system. The palletizing systems imply eliminating the times consumed with the alignment, fixing and clamping of the workpieces, these systems consisting of several mechanisms: the pallet, the automatic pallet changing mechanism, the positioning mechanism and the pallet clamp/unclamp mechanism. In this paper we present an general overview of the automatic pallet changing mechanisms used both in flexible manufacturing systems and machining centres.

scholarly journals Fast Two-Stage Computation of an Index Policy for Multi-Armed Bandits with Setup Delays

Mathematics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 52
Author(s):  
José Niño-Mora
Keyword(s):  
Numerical Study ◽  
Arithmetic Operation ◽  
Bandit Problem ◽  
Index Policy ◽  
Two Stage ◽  
Second Stage ◽  
Whittle Index ◽  
Set Up ◽  
Computing Method ◽  
Special Case

We consider the multi-armed bandit problem with penalties for switching that include setup delays and costs, extending the former results of the author for the special case with no switching delays. A priority index for projects with setup delays that characterizes, in part, optimal policies was introduced by Asawa and Teneketzis in 1996, yet without giving a means of computing it. We present a fast two-stage index computing method, which computes the continuation index (which applies when the project has been set up) in a first stage and certain extra quantities with cubic (arithmetic-operation) complexity in the number of project states and then computes the switching index (which applies when the project is not set up), in a second stage, with quadratic complexity. The approach is based on new methodological advances on restless bandit indexation, which are introduced and deployed herein, being motivated by the limitations of previous results, exploiting the fact that the aforementioned index is the Whittle index of the project in its restless reformulation. A numerical study demonstrates substantial runtime speed-ups of the new two-stage index algorithm versus a general one-stage Whittle index algorithm. The study further gives evidence that, in a multi-project setting, the index policy is consistently nearly optimal.

A Methodology for the Configuration Synthesis of Machining Centers With Automatic Tool Changer

1996 ◽  
Author(s):  
Hong-Sen Yan ◽  
Fu-Chen Chen
Keyword(s):  
Design Methodology ◽  
Systematic Approach ◽  
Coordinate Systems ◽  
Linear Type ◽  
Open Type ◽  
Tool Magazine ◽  
Automatic Tool Changer ◽  
Configuration Synthesis ◽  
Automatic Tool ◽  
Motion Characteristics

Abstract The purpose of this paper is to present a design methodology for the configuration synthesis of machining centers with automatic tool changer to meet the required topology and motion characteristics. According to the concept of coordinate systems, graph theory, generalization, specialization, and motion synthesis, this design methodology is proposed and computerized, and the machining centers with automatic tool changer up to eight links are synthesized. As the result, for the machining centers with drum type tool magazine, the numbers of configurations of machining centers with 6, 7, and 8 links are 2, 13, and 20, respectively. And, for the machining centers with linear type tool magazine, the numbers of configurations of machining centers with 5, 6, 7, and 8 links are 1, 5, 20, and 60, respectively. Furthermore, this work provides a systematic approach for synthesizing spatial open-type mechanisms with topology and motion requirements.

scholarly journals A novel framework for diagnosing automatic tool changer and tool life based on cloud computing

2016 ◽  
Vol 8 (3) ◽  
pp. 168781401663731
Author(s):  
Shang-Liang Chen ◽  
Chin-Fa Su ◽  
Yin-Ting Cheng
Keyword(s):  
Cloud Computing ◽  
Tool Life ◽  
Automatic Tool Changer ◽  
Automatic Tool

scholarly journals Kinematic bidimensional analysis of the propulsion technique in wheelchair rugby athletes

2020 ◽  
Vol 30 (1) ◽  
pp. 129-133
Author(s):  
Sara Maria Franchin ◽  
Federico Giordani ◽  
Michele Tonellato ◽  
Michael Benazzato ◽  
Giuseppe Marcolin ◽  
...  
Keyword(s):  
Upper Limb ◽  
Cervical Spinal Cord ◽  
Contact Angles ◽  
Kinematic Parameters ◽  
Factors Affecting ◽  
Wheelchair Rugby ◽  
Circular Pattern ◽  
Cord Injury ◽  
Speed Range ◽  
Set Up

Wheelchair rugby is a sport ideated for individuals with cervical spinal cord injury (CSCI) which is extremely important for maintaining their neuromuscular abilities and improving their social and psychological wellbeing. However, due to the frequent changes in direction and speed it considerably stresses the players’ upper limbs. 13 athletes have undergone two sports-related tests on an inertial drum bench and several kinematic parameters have been registered. Most athletes use a semi-circular pattern which is considered protective for the upper limb. With increasing speed, range of motion (ROM) increases. Release angles increment and contact angles reduce, displacing the push angle forward to increase speed. Instead, the more anterior late push angle used to increase velocity is a factor which further loads the shoulder joint. However, other factors affecting propulsion technique, such as posture and wheelchair set up should be studied to further reduce loading on the upper limb.

Study of Co-Simulation of Rehabilitation Robot for Upper Limb Based on Virtual Prototype

2013 ◽  
Vol 712-715 ◽  
pp. 2272-2276
Author(s):  
Zhi Lan ◽  
Zhen Yan ◽  
Jian Jun Xu
Keyword(s):  
Upper Limb ◽  
Virtual Prototype ◽  
Rehabilitation Robot ◽  
Electrical System ◽  
Kinematic Parameters ◽  
Rehabilitation Robots ◽  
Dynamics And Control ◽  
Intellectual Control ◽  
Set Up ◽  
And Control

A novel rehabilitation robot for upper limb, which can implement single joint and multi-joint complex motions and provide activities of daily living (ADL) training for hemiplegic patients, was presented. Based on the software ADAMS and the software MATLAB/Simulink, the virtual prototype and the platform of co-simulation of mechanical-electrical system were set up. On the platform of co-simulation, the rehabilitation robots kinematics, dynamics and control have been simulated, and each joints kinematic parameters, torque can be obtained, and parameters of controller can be also confirmed. It offered reliance for the actual intellectual control of the rehabilitation robot.

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