SOVIET UNIVERSAL ELECTRIC-SPARK MACHINE TOOL

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600330205-7
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: August 26, 2011
• Sequence Number: 205
• Publication Date: July 26, 1950
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/08/31: CIA-RDP80-00809A000600330205-7
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CLASSIFICATION CONFIDENTIALJIM CENTRAL INTELLIGENCE AGENCY REPORT
INFORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS CD NO.
DATE OF
Economic; Technological - Machine tools
DATE DIST. .24 Jul 1950
Book
Sverdlovsk/Moscow NO. OF PAGES 3
SUPPLEMENT TO
REPORT NO.
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Or TN[ U.,no [TAn1 TIITNIN TN! N[ANINI Of NIPIONANI ACT ID
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OF In CONTOITO IN ANT ^AOIA TO AN UNAUTNO[IIID PINION it PRO'
NIIIT[D IT LAW. OI-NODUMON or TNI/ roar II PNONUITOO.
THIS IS UNEVALUATED INFORMATION
Elekt,oiskrovaya obrabotka metallov (Electric-Spark Machining of Metaa.s).
SOVIET UNIVERSAL ELECTRIC-SPARK MACHINE TOOL
V. M. Baranov
G. L. Perfil'yev
A nzstvarual-Llectrir,%=k-machine tool with automatic electrode feed is
suitable for performing various metal-cutting operations and for experimenting
with various methods of electric machining.
The work piece is secured to the bed plate by a clamp. The electrode is
secured to the tool head by another clamp. The carriage which carries the
tool head with the electrode can travel vertically on its guide screw; a fly
wheel is mounted on this screw. The carriage feed can be either manual or
mechanical. When mechanical feed is used, a motor activates a shaft through a
reduction gear. A dog attached to the shaft strikes a pin which protrudes from
the side of the flywheel. This sets the flywheel and attached guide shrew into
motion. As a result, the tool-carriage feed moves downward. Two bus bars con-
duct the current from the capacitor to the work piece and electrode by means of
wires.
The oil tank ii lifted with a hand crank through a system of levers so
that the bed plate with the work piece and electrode are submerged in the
liquid dielectric.
The clamp which secures the tool head on the carriage adjusts the vertical p
depending on the typenofhheand wear. ad required,esuch as
permits qof the uick tool-head change in
a head for the contactless method, a head with vibration feed of the electrode,
or a head with electromagnetic feed of the electrode, i.e., with a so-called-
floating spindle. In the latter cases the carriage serves only for the initial
setting of the tool. When the operation is a long one and there is a great
deal of tool wear, periodic manual adjustment is accomplished through the car-
riage.
DNF$D W#.LM
CLASSIFICATION CONFIDENTX L
STATE NAW NsRB DISTRIBUTION-"
ARMY AIR FBI
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The large-diameter bus bars permit easy feeding of current to various-
sized tools and work pieces. A cross-connection socket permits change of po-
larity and quick disconnection of leads so that if the tank should burst into
flame, an iron cover could be put over the entire apparatus. The tank may
catch fire during experimentation with easily inflammable media if a spark
jumps over the surface of the tank.
The unit which feeds the current.to the apparatus consists of a direct-
current motor-generator of 250 volts, 15 amperes, and a condenser bank (C =
300 microfarads), which are connected in an ordinary circuit with appropriate
resistors and measuring instruments.
In making a milling cutter for high-speed milling, hard-alloy blades had
to be cut according to a drawing. The width of the blade was 7 millimeters
and the length of cut was 25 millimeters; therefore, the cross section of the
cutting surface was 175 square millimeters. The cutting was done with a 1.5-
millimeter-thick cuprite bar, the width of which was greater than that of the
blade at the point of cutting. The blade being cut was clamped in a special
jig and mounted on the table in the apparatus. The jig had a slit 1.5 milli-
meters wide for guiding the electrode bar along the line of cut. The other
end of the bar was secured by a jig on the tool head. The use of the jig con-
siderably simplifies the construction of machine tools for electric-spark ma-
chining, making it possible to manufacture them without complex or expensive
precision guides which are usually found on metal-cutting machine tools. The
feeding was done automatically by the motor through a reduction gear since
the cutting was carried out by the contactless method.
Electrical conditions for the cutting were as follows: capacitance, 200
microfarads; potential, 150 volts direct current; charging current, 6 amperes.
Time required to cut one blade was 15-18 minutes. The wear of the cuprite
bar when cutting the hard-alloy blade was equal to twice the thickness of the
blade being cut.
The cutting of 12x12-millimeter bars of tempered carbon steel was accom-
plished in 2 to 3 minutes with a 1.5-millimeter-thick copper bar on this same
machine tool with 200 microfarad capacitance, 175-volt potential, and an 8-am-
pere charging current.
piercing a hole in 21-millimeter-thick red-hot sheet steel for manufac-
turing a matrix for a die was done on this machine tool with a hollow profile
punch made from copper tubing which was compressed on a mandrel to the re-
quired shape. Various operating conditions were used in piercing the hole to
determine which would be most effective when machining with manual feed and
by the contactless method. Results of the experiment are given in the follow-
ing table:
Depth of
Pass for Total
Given Depth of Time per Capaci- Charging Time per
Setting Pass pass tance Voltage Current Mm of Cut
(mm) (mm) (min) (mfd) (volts) (amp) (min)
8 1.8 80 200 120 5-6 10
10 8-18 25 200 150 8 2.5
3 18-21 4 200 170-200 10-12 1.33
From the table it is clear that when the voltage and current are increased,
the productivity of the process increases considerably. Under the last setting
the entire operation took only 35 minutes, whereas ..for the first setting, 220
minutes were consumed.
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FIR
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The industrial use of electric-spark machining is expedient in the follow-
ing operations: cutting hard-alloy blades of any profile for soldering on
edges of complex and irregularly shaped tools; drilling hard-alloy drawing dies
of any profile with diameters as small as 0.2 millimeter without the use of ex-
pensive tools and abrasives; granulating various metals; engraving; making pro-
file recesses; extracting, quickly and cheaply, broken tools from parts such as
internal combustion engines, pneumatic machines, etc., without damage to them;
manufacture of small blanking dies and swaging (ob'yemnyy) dies; and grinding
cutting tools with hard-alloy tips. This machine tool can also be used for
further research work on the process.
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CONFIDENTIAL
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