MECHANIZING THE MANUFACTURE OF STANDARD MASTER CAMS OF COMPLEX CONTOUR FOR MULTI-CUTTER DUPLICATING LATHES

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600270409-8
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 8
• Document Creation Date: December 22, 2016
• Document Release Date: September 19, 2011
• Sequence Number: 409
• Publication Date: December 20, 1949
• Content Type: REPORT

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CENTRAL INTELLIGENCE AG Kf gU6N111 SPORT
INFORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS CD NO.
LANGUAGE
COUNTRY USSR
SUBJECT Technological - Machine tools
IaOW
PUBLISHED Monthly periodical
WHERE
PUBLISHED Moscow
DATE
PUBLISHED Feb 1948
7515 DOCUXINT CONTAINS IMTOINATION AFFECTING THE NAT10SA10157105
of THE UNITED STATUS NITMIN THE NWAMINO OF ISTIGNANt ACS $0
G. N. C.. SI AND 0N. AS 0550010. ITN 000NISIASIOM OR TN1 EIYIi141ON
O7 ITS 0057117115 ANT KARN/R TO AN INAUTMOMISXO 711101 11 PRO-
NINITIO It LA4. IR1'N070CTIOR OF TNIM FOSS tf FRONIIITOO.
DATE OF
INFORMA1ION 1948
DATE DIST. 60 Dec 1949
NO. OF PAGES 8
SUPPLEMENT TO
REPORT NO.
THIS IS UNEVALUATED INFORMATION
MECHANIZING THE MAPIIFACTURE OF STANDARD MASTER CAMS OF
COMPLEX CONTOUR FOR M31TI-CDTTO DUPLICATING LATHES
B. A. Shehuharev
LaTjreate of Stalin Prize
DISTRIBUTION
I ARMY KJMR FBI
I I
I I I I 1! 1! I I
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L .Lu .rag are appouuou j
The most widely used types of equipmedJfor machining complex -contoured- cam-
sbaft came and crankshaft journals for airplane, automobile and tractor engines
is the mult+.-cutter duplicating lathe. In output uncl precision it satisfies the
demands of sass production by making it possible to machine all the came and
journals simultaneously.
A special feature of the machine is the complex movement of the cutters dur-
ing production: in addition to a forward motion in an axial direction. at{d a back-
and-forth motion in a radial direction, the cutter also executes an pec}llatory
motion in the vertical p]ane, the purpose of which is to pro"rve an.exaet or.ap,
proxisa*:e uniformity in the cutting angle of the ,utter, thereby aesid-*ngl,oleaa-
out production.
In all machines for this purpose the complex movement men`taned is obtained
through the simultaneous action of two master came on a system composed of a'rest
auu an omoillatirag tool ALVLileL-.
As shown in Figure Ia, the mechanism consists of a guide (1) fastened to the
bed of the carriage, a rest (2) with a roller (3) which moves along the guide and
is presses against the master can (I) by a spring (4). An oscillating tool hdder
(6) with a roller (7) is held in a groove of the rest at axis (5).
The action of the spring (8) and the cutting force press this roller'.pgainst
the master can (II). The shafts on which the master came are fitted are .chlmeoted
by a gear transmission to the spindle of the machine and rotate with the -saw
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number of revolutions as the spindle. Due to the action of the master cam
(I), the rest with the tool holder executes a back and forth motion in a
ftwiat*ital plane, while from the other cam the cutter nolder gets a rocking
motion around axis (5) In the vertical plane. As a result of the 3o1nt
action of The two mater cams, the cutter fixed in the tool holder traces
the required outline of the part is the plane. Because of the lengthwise
motion of this mechanism relative to the macnined'erticle, the contour
can be machineu to any length desired.
Until now the designing and manufacture of master came have presented
great d. fioultiee. The construction of profiles (1) and (II) is an extremely
tedious operation, demanding the greatest attention and precision; it moat
be carried out on a fine radial grid on a magnified scale. The points
obtained are c+nnected by selected arc., of circles. This first approximatiom
introduces inevitable devia'_loms, and the subsequent reduction of the contours
to the natural size in the tracing on metal causes additional distortions.
The production in metal of standards for similar master cams, from
which a set of working came are then produced, entails the operations
described below.
$~ means of a gauge system, standards 10 millime?'.ers thick are prepared
point by point (po toohkam). Two standards, produced in this fashion, serve
an models, and by duplicating them on a relieving lathe the so-called "master-
cam" are prepared. Before heat treatment, the master came are mounted on
a machine for profile checking and finishing,
This operation consumes a great deal of time. Its completion requires an
expert gauge maker with a thorough grasp of the kinematics of the mechanism
and k nowlndge of the influence of each element in the profiles of the master
cams on the results of the final product.
In organizing the production of duplicating lathes at the "Kraanyy proletariy"
Plant and while working out the technological production of "master duplicators,"
tht, author tried to achieve the greatest possible mechanization of the labor-
consuming processes described and finally worked out a method for producing
master duplicators with great precision, according to the known coordinates of
the centers of elemental area forming the profile of the part. Thus, he
completely eliminated these labor-consuming design operations with their
inevitable didfecte, and also manual gauge work in the finishing process.
The theoret'cal basis for this method and the design of the machine are
treated in this article.
All the above kinematic machine systems keep the angle of the cutting edge
constant for any poist on the circumference, if the cutter in its movement
along the part in ahwahs located in the same plane, e.g., 'lamped so that the
upper edge of the cutter always remains in plane %--%, passing through the
axis of the article an shown in ;igu=e 3a. In other words, the cutting edbe
of the tool at any cutting point must form a constant angle with the radius
of the curvature.
Let us now examine the case where the axis 01 (Figure 3b) of a rotating body
being machined does not coincide with the axis of rotation 0 in a lathe with
an oscillating cutter holder. Let us determine, by plotting, the position of
the cutter for various points of the profile on condition that the cutting
angle of the cutter is kept constant, i.e., the angle formed by the cutting
edge and the radius df the profile curvature at each of its pointy.
- p .
CONFIDENTIAL
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in the l or a point a, with the axis 01 of the article being machined located'
pl axe X--X which passes through the axis of rotation 0 and has the
point a (the cutting point of the cutter), the position of the cutting edge of
the tool (at an angle Tto the plane X--X) will be the same as shown by Figure 3a,
since for any given point the radius of the profile curvature lies in the
plane g?.-X.
For a position corresponding to erotation of the part to any angle C x, the
position of the cutter, while keeping the crating angle unchanged, is shown
by the dotted lines in Figure 3b. To plot this position it is obviously
necessary that the line X--X from the center of 01 should be intersected at
the point b1 by the radius R .- A, where R is the radius of the article being
finished and A is the left xrm of the cutter holder, i.e., the distance from
its rocking point to the cutting tip. Points 0'1 and b1 are joined by a
straight line. The point al where th.s straight line intersects the dotted
circle with a point curvature equal to radius R from the center 0'1 deter-
mines the position of the cutter tip for a given angle of rotation.
As may be seen from Figure 3b, the cutter occupies the pciition determined,
maintaining a constant angle with the radius of curvature of the profile at
this point, i.e., the cutting angle.
During a complete revolution of the blank, the center 0 of the rotating
body describes a circle of radius r equal to the eccentricity (the distance
010), and the point b (the axis of the oscillating cutter holder) executes a
back-and-forth motion along the straight line X--X with an amplitude-equal
to 2s', and is displaced at any position by a constant amount R.+ A from the
center of the rotating body, i.e., subject to the same law of motion as a
piston in a crank drive.
Moreover, the deflection angles of the oscillating cutter holder will
be Such that the cutting angle of the cutt..r fastened to it will be kept
constant for all positions of the part being machined.
Banco, it follows that if the oscillating cutter holder is joined with
the axis 0 of the rotating body by a rigid link (guide rod) of length
L - R+A an the same axis 0' is joined with the axis of rotation 0 by the
crankshaft, the length of which is equal to the eccentricity 001 = r, then
this system, for any angle of turn during the rotation of the crankshaft,
will determine the positions both of the cutter holder and the rest and,
consequently, will determine the trajectory of the cutter during,the turn-
ing of the eccentric with the axis of rotation 0.
Now let ue examine what happens to the contour of the cam which is
formed by the linked arcs of circles described from different centers during
the tracing of the cam, e.g., in Figure 4, the contour takes the following
shape: in the section a4 a11, a rotating body with an aria coinciding with
the axis of rotation 0; in the section from al to a2, a rotating body with a
radius B1 and axis 0 , which does not coincide with the axis of rotation 0
(see Figt're 3b); in the section a2 a~jS, a rotating body with a radius R2
and.axis??02, also-not..caincidIA4-vith'O'and eeparated'from it by a distance
r'1.. The section a, - ak is analogous to section a, - a,,, Therefore, the
maoelned contour of-this cam is composed of the circular`eecti.n a4 - al and
the three eccentric sections (relative to the axis of rotation 0) al - a.;, a2-
a3, &3 - a4.
By using, for these sections, a eyste;,. of guide rode and crankshafts of
corresponding sizes, it would be possible to force the rest and tool holder
system to take such positions in a plane perpendicular to the axis of rotation
of the parts that the cutter point would circumscribe the given profile. Fig-
ures 5 and 6 show the instantaneous positions of the cutter holder when the
cutter to at points a1 and a2 of the profile (Figure 4). A diagram under each
illustration. gives the dimensions of the guide rods and crankshafts.
COPFID P 'IAL
CON.
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conclusions. The model is composed of three disks connected by gear drives
with a gear, ratio of 1 : 1. The coordinates of the disk centers are assured
to be equal to the coordinates of the axes of the spindle and the two mentor
shafts in the machine. The rest, rollers and oscillating cutter holder are
mach'-ne. The directions in which the disks rotate, indicated in Figure 7 by
arrows, coincide with time directions in which corresponding parts of the
glas with holes bora1 in it in a straight line passing through the axis
of rotation of the holder and the cutter tip at distances corresponding
to the radii forming the can profile of the part, calculating from the
cutter tip. The profile of the can to be machined was drawn upon disk III
with an axis of rotation coinciding with the esis of the spindle, and holes
of the sane dimensions as those in the guide rod were made at the centers of
al - a2 in Figure 4). During rotation of disk III the tip cutter-model
the required profiles for the luster cams in the Pori of curve envelopes
comprising two sets of circles.
At point 5 of the can profile an are with a radius R3 passes through
an are with a radius Rhh which at this point has a can=on tangent with it.
Therefore, at this poitdt it is necessary to change the lengths of the
crankshaft end comna+ting rod (see Figure 4). In the model, this moment
is itself determined by the coincidence of the bole in the guide rod,
at a distance Ri, free the nutter tip, with the hole corresponding to the
center of an are of radius R4 on disk III. If in this position the guide
rod is connected with the disk by a second pin, passed through these holes
which are coaxial at the given moment, and the first pin is rammed, then
on further rotation of disk III the cutter tip will describe an outline of
the top of the can, and the saddle and cutter holder system will pass through
oarz4.ponding intermediate positions. By changing, in this manner, the posi-
tion of the piss In the holes of disk III and in the guide rod and by tracing
the positions of the rollers on disks I and II, it is possible to get the
whole contour of both cam.
The can profile shown in the above illustration possesses a certain
peculiarity at point 3: this profile does not pass smoothly from are Ri
to are R2 (Figure 8) but instead breaks off. Let us examine two positions
of the cutter at this point: first, at the moment of arrival of the cutter
along an arc of radius R'jj at the break point, and, second, at the moment
of leaving that point wits an are of radius R.
Passing along the arc of radius R',~S to the break point, the cutter
will occupy position I, keeping its cutting angle -r constant (the angle
formed by the direction of its cutting edge with a straight line passing
through the center of curvature of the giwca contour section). At the moment
of leaving this same break point while starting on its path along an mire
of radius R'2, if it is to keep the cutting angle constant, the cutter sat
take position II. Therefore, to keep this angle constant in passing through
this point, the cutter sat rotate through an angle around its tip. There
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The break point of the profile can be considered an arc of radius zero.
The rotation of disk III continues as long as the hole in the guide rod located
at a distance equal to B2 from the tip of the cutter does not coincide with
the hole in the disk corresponding to the center of the arc }R'2. The rest
and cutter holder eye-van, meanwhile, will also complete a certain aoaesnent,
wrom these statements it is obvious that:
1. To manufacture complex asetor cams it is not necessary to plot then ort
2. Production of such came in metal can be mpmahanir.ed.
In some cases the master came, I and II, obtained by the above method,
somleehat distort the part's contour at the transition points from the side
In its course along section A, the center of the roller, at the position
of the latter corresponding to the break point of the profile, mist be located
at point 0 and must rest upon section A at point a. But this point does not
exist slue it is out off by the roller movement along section B; in practice,
the roller on approaching the function point of arcs A and B begins to roll
across this point, and the center of the roller will not reach the theoretical
point 0 by a certain distance 3 ('Figure 9). 'Min produces a less angular
rise in the cutter tip, and its premature transition during a certain angle
of rotation of the part being machined causes distortions in this contour
section of the part. Although this distortion occurs in a very snail section
and is insignificant in amount, it is desirable, nevertheless, to eliminate
it.
Theoretically this can be done only by decreasing the diameter to zero;
but even if this mare possible (in practice, of course, it can only be
approximated), it would be necessary to substitute slide friction for
rolling friction, with a sharp edge on the contour of the can, thereby
causing it to weer out rapidly. In practice it he-3 proved possible to
oampeasate for such an error in profile II by correcting the corresponding
part of profile I.
The production of the first pair of standards ehowe& all the -advantages
of this method. The working cans did not need any finishing and produced
the given profile accurately. This method makes it possible not only to
reduce greatly ti!,., period of manufacture for the machin-e but also to produce,
fan previously manufactured nachiaes, sets of came which ooftespond to new
profiles for the parts.
The former difficulties in producing standards have completel3 disappeared,
since there is no need for plotting or gauge finishing.
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Bona sasples of siailar naohinei have already been built for various types
3i duplicating lathes.
A asohiae vill woos be produced for profiling oaae for automatic aaohinss,
built an an analogous principle of asohaniaation of the motion of a grinding
wheal an the principle stated, as sell as a maohina for profiling a aaatar
cote sith a closed oampler, curve for a profiling maohine used for mesohining
grooves in pilgaor (pip') ulna.
fAppsadad figures folio+J
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COIwm. 7AL
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