EXCHANGE OF EXPERIENCE

N E W D E S I G N O F P L A S M A - A R C C U T T E R S

S T E E L S A N D N O N F E R R O U S M E T A L S

A. S. A d e r i k h i n , V. G. A r ' k o v , V. I . K i r i l l o v , V. M. K o r d a k o v , a n d V. I . P e c h e n n i k o v

F O R A L L O Y

UDC 621.79.034:[669.15+669.2.8]

The design of a mechan ized p l a s m a cu t t e r 3485M and a hand-he ld p l a s m a cu t te r GI~R-50A (Fig. 1) with high s e r v i c e durab i l i ty under any working condit ions has been developed* at the VNIIPTkhimnef te- appa ra tu ry [1 ].

Technica l C h a r a c t e r i s t i c s of the P l a s m a - A r c Cut ters

Power , kW . . . . . . . . . . . . . . . . . . . . . . . . . . . Working cu r ren t , A . . . . . . . . . . . . . . . . . . . No- load vol tage , V . . . . . . . . . . . . . . . . . . . Th ickness of meta l cut, mm:

a l loy s tee l and b r a s s . . . . . . . . . . . . . . . 50 copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

D i a m e t e r of tungsten e l ec t rode , mm . . . . 4-5 Ftow r a t e of cool ing wa te r 8-10 Ex te rna l d imens ions of a r c head, mm . . . 500 • 160 x 100 Weight of a r c head, kg . . . . . . . . . . . . . . . . . 1.3

GER-50A 3485M

56 120 250-500 300-500

180 300

120 70

5-8 8-10

280 • 145• 60 4.7

The construction of cutters GI~R-50A and 3485M is identical. Figure 2 shows the construction of the

head of the hand-held plasma-arc cutter GI~R-50A.

The tungsten electrode 3 is secured in the guide sleeve 2 by a cam type clamp 4, permitting conven- ient and reliable fixing of electrodes having a wide range of diameters without the necessity of taking the

cut te r apar t .

The fixing unit of the in te rchangeable p l a s m a - f o r m i n g tip 6 to the c u r r e n t - c a r r y i n g pa r t of the b u r - ne r housing has only one rubber sea l , which s impl i f i e s the mortaring of the tip and i n c r e a s e s the r e l i ab i l i t y of the joint . The in te rchangeable fo rming nozzle 7 is mounted on the tip by means of a p r e s s - f i t cone p e r - mi t t ing rap id r ep l acemen t of the nozzle . Cur ren t is suppl ied to the cu t te r by copper leads 8, so lde red to the connect ions 9 through which wate r is suppl ied and d i scha rged . The cooling sys t em, while being r e l a -

t ively s imple , ensures r e l i ab l e cooling of the c u r r e n t - s u p p l y means , nozzle , housing, e l ec t rode fixing unit, and par t ly the e l ec t rode i t se l f . Argon and ni t rogen are suppffed to the p r o - tec t ive chamber by the pipe 10.

Cente r ing of the e l ec t rode re l a t ive to the nozzle and adjus tment of the optimum gap between the e l ec t rode and nozzle a re poss ib l e by r eason of the one - s ided se lec t ion of the rad ia l gap between the tip and the cap nut 5 fixing it to the housing.

Axial feed of the e l ec t rode for adjust ing the optimum gap Fig . 1. Hand-held p l a s m a - a r c cut te r between the nozzle and e lec t rode is by rota t ion of the nut 11

GI~R-50A. *A. V. Ba~yrev and I. G. Kladnitskii assisted in the work.

r � 9 Consultants Bureau, a division of Plenum Publishing Corporation, 227 [~'est 17th Street, New York, ] I

[ N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without I [

] permission of the publisher. A copy of this article is available from the publisher for $15.00. I I

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Fig. 2. Head of hand-held p l a s m a - a rc cut ter G]~R-50A: 1) housing; 2) guide sleeve; 3) tungsten e l e c - trode; 4) cam type clamp; 5) cap nut; 6) p l a s m a - f o r m i n g tip; 7) in- terchangeable nozzle; 8) c u r r e n t - ca r ry ing lead; 9) connecting piece; 10) gas pipe; 11) nut; 12) pin.

sc rewed on the guide s leeve . Due to the pin 12 and a keyway in the guide s leeve , the e lec t rode is p revented f rom rotat ing during feed. Center ing and adjustment of the neces sa ry gap between e lec t rode and nozzle is done in accordance with a gauge inser ted in the opening of the tip in place of the nozzle.

The a r r angemen t of the gas and w a t e r - c a r r y i n g pipes and the construct ion of the handle with push- button switch ensure convenient visual observat ion of the cutting p roces s .

Lengthy se rv i ce of the p l a s m a - a r c cut ters GI~R-50A and 3485M under production conditions have shown them to be re l iab le and convenient in operat ion. The total annual saving resul t ing f rom their in t ro - duction at 12 plants has been more than 85,000 rubles .

1.

L I T E R A T U R E C I T E D

Author ' s Cer t i f ica te No. 241573, Izobre tenie , P romysh lennye Obraz t sy , Tovarnye Znaki, No. 14 (1969).

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