Apparatus for the machining on cylindrical surfaces on metal-cutting lathes

An apparatus for the machining of cylindrical surfaces on metal-cutting lathes. The apparatus has a housing, a toolholder with tools and a head with deforming rollers. The toolholder is provided with an opening through which the work passes, and the tools are clamped in the toolholder so that their points are opposite each other. The housing is topped by guides secured in a plane at right angles to the direction of longitudinal feed with provision for rotation during setting-up, and the toolholder is fitted to the guides with provision for floating in the course of machining.

The present invention relates to tools used for the machining of metals 
combined with plastic deformation at the surface and is specially 
concerned with an apparatus for the machining of cylindrical surfaces. 
The invention disclosed can be used to advantage on lathes for the 
machining of shafts, piston rods of hydraulic cylinders, axles, and 
similar parts. 
Lathes equipped with the disclosed apparatus for the machining of 
cylindrical surfaces may find application in the automotive and 
agricultural machine industries, in road machinery building, and 
elsewhere. 
Known in the art is an apparatus for the machining of outside cylindrical 
surfaces on metal-cutting lathes. It comprises a toolholder with a tool 
and a head with deforming rollers spaced equidistantly apart all the way 
along a circumference, the toolholder and head being consecutively 
arranged in a housing. 
In the known apparatus, the toolholder with the tool is movable in the 
course of setting-up and fixed at rest during machining. This way of 
fitting imposes variable turning loads on the tool resulting from section- 
or lengthwise variations of the stock to be removed or hardness or from 
misalignment of the apparatus relative to the lathe spindle. Anyhow, the 
accuracy of machining is impaired, especially when the shaft turned is not 
stiff. 
It is an object of the present invention to enhance the accuracy of 
machining. 
Another object of the present invention is to improve the productivity of 
machining operations. 
The essence of the invention is that, in an apparatus for the machining of 
cylindrical surfaces on a metal-cutting lathe that has a housing in which 
there are consecutively arranged a toolholder with a tool and a head with 
deforming rollers, the toolholder is provided with an opening through 
which the work passes and clamped therein is another tool located so that 
the points of the two tools are opposite each other. The housing is topped 
by guides secured in a plane at right angles to the direction of 
longitudinal feed with provision for rotation during the setting up, and 
the toolholder being fitted to the guides with provision for floating in 
the course of machining. 
It is expedient that the guides are provided in the form of a disc with a 
through slot extending diametrically and the tool-holder is given the 
shape of a rectangular plate arranged in this through slot. 
Simple as they are in point of construction, the guides and toolholder of 
this kind are reliable in operation. 
The apparatus for the machining of cylindrical surfaces on metal-cutting 
lathes provided by the present invention enhances the accuracy of 
machining simultaneously with increasing labor productivity and extending 
the life of tools.

An apparatus for the machining of cylindrical surfaces on metal-cutting 
lathes comprises a housing 1 (FIG. 1), a toolholder 2, guides 3, and a 
head 4 (FIG. 2) with deforming rollers 5. The toolholder is provided in 
the form of a rectangular plate with an opening 2a through which work 6 
passes and two recesses 7 (FIG. 1) and 7a in which tools 8 and 8a, 
respectively are located. The recesses 7 and 7a are arranged so that the 
tools 8 and 8a contained therein are disposed opposite each other, with 
their points being coaxial. The tool 8 is fitted with provision for 
adjustment to a given turning diameter, using a kinematic pair comprising 
a nut 9 (FIG. 2) and a screw 10. The tool 8a is immovably clamped in the 
toolholder 2. 
The toolholder 2 is installed integrally with the tools 8 and 8a in the 
guides 3 with provision for floating in the course of machining. 
The guides 3 are provided in the form of a disc 11 with a through slot 12 
extending diametrically to accommodate therein the toolholder 2. The disc 
11 is fitted to the housing 1 with provision for rotation during the 
setting-up, elongated bolt holes 13 (FIG. 1) being provided to that end 
all the way along its circumference; screws 14 are inserted into the bolt 
holes 13. 
The guides and toolholder can be provided in any other suitable form. 
The head 4 is provided with a cage 15 carrying the deforming rollers 5 
spaced equidistantly apart all the way along the circumference in slots 
and contacting a supporting cone 16 contained in the housing 1. The 
toolholder 2 is held fast in the slot 12 by bars 17 and 18. The cooling 
system is neither described herein nor shown in the accompanying drawings, 
being out of the scope of the invention. 
The apparatus for the machining of cylindrical surfaces on metal-cutting 
lathes operates on the following lines. 
The housing 1 is installed on the carriage (not shown) of a lathe. The disc 
11 is fitted to the housing 1 so that the parallel sides of its slot 12 
are arranged in horizontal planes and is secured in place by the screws 
14. The elongated bolt holes 13 facilitate the installation, enabling the 
disc 11 to be turned in any direction indicated by arrows A and B. 
The tools 8 and 8a are set at a given turning diameter outside the lathe, 
using a standard piece of work. The toolholder 2 with the tools 8 and 8a 
set at the given diameter is inserted into the slot 12 and secured in 
place by means of the bars 17 and 18. On placing the work 6 between the 
centres (not shown) of the lathe, the deforming rollers 5 are set by means 
of the cage 15 at a diameter which depends on the interference to be used 
in order to obtain a given surface roughness of the work 6. On completing 
all preparations and admitting the coolant-lubricator into the apparatus, 
the work is set to rotate in the direction of arrow C and the lathe 
carriage is fed longitudinally in the direction of arrow S. As the 
toolholder 2 displaces along the axis of the work at a given rate of feed, 
the tools 8 and 8a remove the prescribed stock, reducing the work 6 to a 
size specified for the surface rolling. The deforming rollers 5, 
travelling in the wake of the tools 8 and 8a, smooth down the minute 
surface irregularities due to the effect of plastic deformation. 
When the machining is completed, the work is taken down from the lathe and 
the apparatus is returned into its original position where the rollers 5 
are automatically reset for the given turning diameter. 
In operation, the toolholder 2 is floating at right angles to the 
longitudinal feed of the lathe carriage in the direction of arrow S, 
uniformly removing the stock all the way down the work 6. In addition to 
ensuring high accuracy of machining and good surface finish, the apparatus 
with the floating tool-holder provides dimensional stability of the tools 
which equally share the turning load. 
A pilot model of the apparatus provided in accordance with the present 
invention and fitted to a lathe has improved the accuracy of machining up 
to Class h.sub.7 -h.sub.8 with a simultaneous increase in labor 
productivity half as much again.