Abstract: A truing operation for straightening out of true work pieces such as crankshafts, must not again reduce the fatigue strength of the work piece achieved in a previous strengthening operation. This is achieved by a truing operation, wherein locally bounded compressive residual stresses are induced in a surface layer zone of the work piece by a hardening operation, whereby the respective out of true deformation of the work piece is at least reduced. The truing operation is repeated until the out of true deformation is eliminated. The compressive residual stresses are induced in a surface layer zone of the work piece by a locally limited hardening operation, e.g. a surface strengthening rolling operation. By appropriately varying the extent of hardening or the rolling force respectively, any out of true deformation may be even completely eliminated. A machine for performing the method is also disclosed.

Abstract: In a straightening or truing operation for straightening out of true work pieces the characteristic fatigue strength or an increased fatigue strength achieved in a previous strengthening operation of the work piece to be straightened, is maintained. This is achieved by a truing operation, wherein locally bounded compressive residual stresses are induced in a surface layer zone of the work piece by a hardening operation, whereby the respective out of true deformation of the work piece is at least reduced. The truing operation may then be repeated until the out of true deformation is eliminated. The compressive residual forces are induced in a surface layer zone of the work piece by a locally bounded hardening operation or a strengthening rolling operation. By appropriately varying the extent of hardening or the rolling force respectively, the magnitude and angle of any out of true deformation may be affected so as to be even completely eliminated, for example.

Abstract: In a straightening or truing operation for straightening out of true work pieces the characteristic fatigue strength or an increased fatigue strength achieved in a previous strengthening operation of the work piece to be straightened, is maintained. This is achieved by a truing operation, wherein locally bounded compressive residual stresses are induced in a surface layer zone of the work piece by a hardening operation, whereby the respective out of true deformation of the work piece is at least reduced. The truing operation may then be repeated until the out of true deformation is eliminated. The compressive residual forces are induced in a surface layer zone of the work piece by a locally bounded hardening operation or a strengthening rolling operation. By appropriately varying the extent of hardening or the rolling force respectively, the magnitude and angle of any out of true deformation may be affected so as to be even completely eliminated, for example.

Abstract: The known turn broaching of crankshaft main bearings is not suitable for broaching crankshaft bearing pins for the connecting rods because that would require locating the rotational axis of the crankshaft in the connecting rod bearing pins, whereby the crankshaft would rotate eccentrically. The resulting unbalances prevent driving the crankshaft with the r.p.m. required for the turn broaching operation. To avoid this problem a broaching lathe for the rotational or turn broaching of crankshaft connecting rod bearing pins is equipped with a steady rest including a rotating support device which permits mounting the crankshaft in the lathe in such a way that the rotational axis coincides with the axis of the connecting rod bearings of the crankshaft.

Abstract: A broaching tool is provided with at least nine cutting tool edges arranged at its circumference. The cutting tool edges cover only a certain sector along the circumference of a tool disk while leaving another sector between a first and last cutting tool edge free of cutting tool edges. This feature enables moving a tool axially relative to a work piece without first moving the tool radially relative to the work piece. Further, the tool can be moved radially without damage. These movements are performed when the sector without cutting tool edges faces the work piece. This sector without cutting tool edges has an opening angle of less than 180.degree. and it provides a spacing and free space relative to a work piece. Thus, work piece surfaces that have been machined by the cutting edges, are free of these cutting edges if and when the other sector faces the work piece.

Abstract: Work pieces, especially of rotational symmetry, are machined in a rotary broaching operation. The machine tool for this purpose has a tool carrier carrying a plurality of cutting edges arranged on a curved path in a radial work piece plane. In order to reduce down-time and to simplify the construction of the broaching apparatus, the insertion of a work piece blank into the apparatus and the removal of a finished work piece from the apparatus are preferably performed without interrupting the motions of a tool carrier. For this purpose the tool carrier is provided with a zone which is free of cutting tool edges. This tool free zone of the tool carrier is located downstream of the last cutting edge as viewed in the rotational direction of the tool carrier. This feature avoids the need for a return stroke of the tool carrier. Accordingly, respective return slides and return controls are also obviated.

Abstract: A rolling mill tool for smooth rolling slightly convexly or concavely curved surfaces of rotationally symmetric work pieces, such as bearing journals of crankshafts, has a milling roller with a slender and hence flexing configuration for conforming the shape of the milling roller to the curved shape of the work piece surface. Such a milling roller achieves a satisfactory rolling force or load distribution. The rolling force which is applied to the milling roller by a support roller is sufficient to flex the milling roller along its lengthwise axis to assume the shape of the contour of the work piece.

Abstract: The milling of work pieces having at least one bore in the surface to be milled by roller action, is performed by controlling the size of the force applied to the work piece surface in accordance with the rotation of the work piece and in accordance with the location of the bore. The control is such that the rolling force or pressure applied when the roller contacts the bore is smaller than the rolling force or pressure when the roller contacts the work piece surface outside the bore. The rolling force may even be applied in a pulsating manner in the zone of a bore. A minimum of the applied rolling force is reached at the latest when the roller passes over the bore diameter. In this manner undesirable deformations of the work piece surface, especially in a ring zone around the bore, are avoided.

Abstract: Surface-hardening and smoothing rolling apparatus includes at least one movable rolling device at least including a die carrier with at least one backing element, as well as at least one additional rolling device, the movable and additional rolling device being carried by a standard disposed on a slide, the movable rolling device being arranged so that the position thereof is changeable relative to that of the additional rolling device in a radial plane of a crankshaft to be rolled.

Abstract: A rolling apparatus with a driving mechanism for a workpiece to be rolled and with at least one movable rolling device includes at least a die carrier with one rolling element and a die carrier with one backing element and including at least an additional one of the elements carried by at least one of the die carriers, the rolling element being changeable from one position thereof to at least another position thereof, one of the positions being a working position, at least one of the elements consisting of the rolling element in the working position thereof and at least one backing element associated therewith being kinematically connectible to a power actuating device.

Abstract: Surface-hardening and smoothing rolling machine for rolling at least eccentrically disposed surfaces on a workpiece, having equipment for seating and rotatably driving the workpiece, and comprising at least one movable rolling device at least including a die carrier with at least one rolling element and a die carrier with at least one backing element, the movable rolling device being movable together with the workpiece, and being arranged in a position which is linearly changeable in a radial plane of the workpiece.

Abstract: Method of deep-rolling of crankshaft pins by applying different rolling forces over a rotational angle (phi) of 360.degree., such as to produce in each angular position a constant enlargement of the angle (alpha) subtended by the mirror faces i.e. the faces connected with the respective transition radii to provide, at least, in the angular region most subject to damage the desired fatigue strength increase.

Abstract: A planishing tool includes an axially slideable adjustment collar. When the collar is retracted to an inactive or adjustment position it may be rotated to vary the operating diameters of the planishing rollers. When the collar is released, the parts are locked against rotation relative to the mandrel in an active or operative position.

Abstract: A crankshaft rolling machine includes a pair of model crankshafts mounted for synchronous rotation. One or more crankshaft rolling units are coupled to the model crankshafts in a manner enabling adjustment of the units along a linear path to adapt the device to the stroke length of a crankshaft to be rolled. The apparatus may be rapidly changed for rolling of crankshafts having different stroke lengths by linearly sliding the individual rolling units relative to the model cranks and thereafter locking the individual rolling units to the model cranks at positions corresponding with the stroke length of the crankshaft to be rolled.

Abstract: Known machines for the machining of crankshafts, in which the machining units for the machining of the crankshaft are supported and moved by operating crankshafts, are not adjustable to different offset angles of crankshafts to be machined. Therefore a machine is proposed for the machining of crankshafts with means for the guiding and taking along of a crankshaft to be machined and with at least two movable devices for the uptake of machining tools or systems, the devices being supported and moved by crankpins of two driven operating crankshafts consisting of several cranks and mounted on main bearing pins, where the individual cranks of each operating crankshaft are fixable relatively to each other and comprise two independent main bearing pins each and are mounted thereon for rotation relative to each other.

Abstract: A cutting tool for internal and external turning has a body with straight main cutting edge, a curved auxiliary cutting edge, and a chip guiding shoulder extending in parallel to the feed advance direction of the tool. The main cutting edge forms a tangent to the curved auxiliary cutting edge. Further, the main cutting edge encloses an angle of 3.degree. to 9.degree. with the direction of the chip guiding shoulder an normally with the feed advance direction. This construction makes the tool substantially independent of tool positioning errors whereby the cutting quality is increased.

Abstract: The present invention relates to a method of cold rolling metal parts to achieve improved surface uniformity and hardening. The method comprises applying to the work piece a pulsating force at a frequency of from about 30 to 300 the duration of the pulses being at least twice the time between pulses. The pulsating force varies from about 10% to 100% above the minimum force necessary to achieve a smooth rolled finish. The method contemplates just statically rolling the work piece and thereafter applying the pulsing force which, in such instance may reduce to zero.