Modular intelligent fixing systems for cutting process

NITA, RALUCA1,2

; AVRAMESCU, VALERIU2 & CRACIUNOIOU, STEFAN

2

1 Phd. Student UPB, Mechanical Engineering and Research Institute

Sos. Oltenitei, 104,

ROMANIA-Bucharest 2 S.C. ICTCM S.A. - Mechanical Engineering and Research Institute

Sos. Oltenitei, 104,

ROMANIA-Bucharest

ralu_magda@yahoo.com, raluca@ictcm.ro

Abstract: - The paper presents some contributions for the intelligent device which will correspond to the actual requests regarding

the processing precision and brings into attention the technical and functional specific characteristics. Starting from the device role

into the technological system, from the necessity to assure the requests during the processing process and the functionality requests

the device concept proposed into the paper integrates along the classical solution, sensors, modern actuation systems, modern

command systems. The executed system for orientation and clamping can assure in real time the actual fabrication requests and

have the advantage of technical and functional characteristics taking into considerations the changes produced into the

technological process.

Key-Words: - Modular System, Sensors, Intelligent Tools, Computers, Data acquisition.

1. Introduction The evolution of modern society, marked by widespread

of the technological innovation has accelerated products

and demands diversification regarding their

performances and imposed precision, reliability and

productivity of manufacturing processes expectations,

systems development in order to be capable to ensure the

new requirements. In order to have the possibility to

process all kind of technological operations on

multifunctional machine tools it is important to design

modular structures for pieces clamping. [3]

For answering to the technological and functional needs

of the processing process the developed structures are

equipped with sensors, drive systems, command and

control assets, so the developed fixing systems are able

to respond in real time requirements of the technological

process, changing them functional characteristics

depending to the changes occurred in the process and in

the initial working sets. [5]

2. Device role in the technological system Principal component of a production process is

represented from technically point of view by the

technological process, which includes various activities

not only at the organizational level, but also at the

economic, managerial etc...

In order to achieve for pieces with complex geometrical

shapes high dimensional precision, roughness according

with imposed technical specifications, it is necessary to

adapt the technological processing to ensure the full

complexity of technical requirements, technological and

functional. [2] Improving processing technologies is determined also by

the evolution of the processing, assembly or control

equipments. Principal components of the working unit as closed

elastic technological subsystem, are the half finished

product - the device - the machine tool - the tool - the

half finished product as shown in fig. 1.

Taking into account that in the working units component

could be one or more tools, so can be processed one or

more pieces, it can be affirmed that the generalized

working unit, as elastic technological closed subsystem,

is designed to give the machine, a particular trajectory to

one or more tools, which to act on one or more half

finished products, that are fixed in a device. [4]

The links between the components elements of the

generalized working unit are realized through linked

elements represented in Fig. 1...3, through half circles,

noted with two groups of letters, the first one being of

the element that belongs to it and the second one that

element that couples with. [1] Devices that are used in the processing on machine tools

are found to be in interdependence with all the

technological bangles, through biunivoce links.

So as shown in Fig. 1 the linking device elements have

the following significations:

-D-HfP – supporting elements that come into contact

RECENT ADVANCES in APPLIED and THEORETICAL MECHANICS

ISSN: 1790-2769 60 ISBN: 978-960-474-140-3

Fig. 1 Generalized device

Fig. 2 Generalized device–linking

element

with the technological supports on the half finished

product HfP.

-D-T – elements for the tools guidance, which come into

contact with the tools guidance surfaces T-D. -D-M – elements for the device placement on the

machine tool. If the orientation and fixing device is treated in terms of

the systemic point of view, we could consider that the

device is formed from a finite number of subsystems,

organologic groups with well-specified role, with proper

organization, but in the same time, being a subsystem of

the technological system. In fig. 1 were represented only

the supporting surfaces of the half finished products and

not the fixing ones. In Fig. 2 were also represented for

the device also the fixing surface noted with the index f

from fixing and index s from supporting.

3. The concept of intelligent orientation

and fixing device The first available intelligent devices could be

considered the universals used for fixing and orienting

the cylindrical pieces, conical and in general of the

pieces with a revolutions axes.

Fig. 3 Device-machine tool

The main features of the universal is that the basing

surfaces coincide with areas of guidance and backs that

materialized the auto centering surfaces a fairly large

range using MD Mechanism as shown in fig. 3.

In the case of prismatic parts, are characterized through

that they have a large basing surface, followed by

guidance and orientation, but in principal are parallel

with them.

In Fig. 4 were represented two parallelepipeds, the

minimum and maximum pieces that can be fixed on the

table. Note that the supporting is the same for both parts,

and requires displacement of the fixing elements for

fixing at the level of the T channels and also on high.

The radial channels assure a rapid fixing system

adaptation in correlation with the half finished product

form and the dimensions of the piece.

The two sledges with radial channels actuated and

commanded by the machine tolls numerical command

system, could be displaced on horizontal, individually or

in the same time, because they have the advantage to

processed half finished products with different shapes

and with different dimensions – fig. 5

The new concept of orientation and fixing intelligent

device includes as principal characteristics the high

modularization level and flexibility, automatic

adaptation of at the effective working conditions

appeared during the technological process with the help

of sensors, actuating systems, command control.

Data collected at the sensors level are transmitted to a

computer where are stocked the normal values for that

process. The values measured by sensors are compared

with normal values. [7]

After that in concordance effective needs of the

processing process can be adjusted the clamping force,

the cutting force or other specific parameters of the

process and event stopping the processing process if the

changes which assure the conditions of geometrical,

orientation and functional precision cannot be respected.

RECENT ADVANCES in APPLIED and THEORETICAL MECHANICS

ISSN: 1790-2769 61 ISBN: 978-960-474-140-3

Fig. 4 Concept-fixing system with radial

channels

Fig. 5 Transversal slide course

Fig. 6 Data acquisition system

4. Conclusions

The designed intelligent device represented a high

modularization level, productivity, flexibility and

adaptation, for the flexible productions systems

configuration but also for the lines and for the

specialized processing systems. The dominant

characteristic refers to the possibility to adapt easily to

different cutting process (turning, milling, drilling,

grinding etc.) in the conditions of the small and medium

production requirements.

The modules from which are realized the devices can be

changed in concordance with the process type and the

clamping imposed restrictions, so the flexible fixing

systems can be used in the most activities domains.

In order to answer to the technological and functional

needs of the processing process the developed structures

are equipped with sensors, drive systems, command and

control assets, so the developed fixing systems are able

to respond in real time requirements of the technological

process, changing them functional characteristics

depending to the changes occurred in the process and in

the initial working sets as in fig. 6. Can be measured

signals that directly measure tool geometry, the distance

between the tools and the piece, the clamping force, the

cutting forces [6]. Values measured by the sensors are compared with the

theoretical values for the process specific to the working

conditions, and in concordance with the obtain results

can be modified different process parameters, and even

stopping the processing process if the conditions that

have influence on the precision processing cannot be

assured.

References:

[1] Bragaru, A., (1998) – Proiectarea dispozitivelor,

Technical Editor, ISBN 973-31-0717-4, Bucharest.

[2] Tache, V., Brăgaru, A. (1976) – Dispozitive pentru

maşini-unelte. Proiectarea schemelor de orientare

şi fixare a semifabricatelor, Technical Editor,

Bucharest.

[3] Costea, A., Rachieru, N. (2005) – Flexibilitatea şi

performanŃele echipamentelor de prelucrare.

Optimizarea proiectării dispozitivelor, Bren Editor,

ISBN 973-648-391-63, Bucharest.

[4] Tache, V., Ungureanu, I., Stroe, C., (1995) -

Proiectarea dispozitivelor pentru maşini-unelte,

Editura Tehnică, Bucureşti.

[5] Nita, R., Craciunoiu, S., Avramescu, V., Marin, G.,

(2009) - Intelligent fixing sistems on

multifunctional machine tools, Proceedings of the

13th International Conference Modern

Technologies, Quality and Innovation, ISSN 2066-

3919, Iasi.

[6] Prospects of the firms: Wharton – Anglia,

Vorrichtungsbau Hohenstein – Germania, Mauser-

Werk Oberndorf GmbH Germania, Helge F. Mara

Prazizionswerkzeuge – Austria

[7] Nita, R., Avramescu, V., Craciunoiu, S. (2009) -

Clamping intelligent modular systems for

cutting process; The 3rd

European DAAAM

International Young Researchers´ and Scientists´

Conference, 25-28th November 2009, Vienna,

Austria

RECENT ADVANCES in APPLIED and THEORETICAL MECHANICS

ISSN: 1790-2769 62 ISBN: 978-960-474-140-3