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:
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 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:
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:
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 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. A machine for performing the method is also disclosed.
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.