GB1223405A - Improvements in or relating to machining of crankshafts - Google Patents

Abstract

1,223,405. Machining crankshafts. HOESCH MASCHINENFABRIK DEUTSCHLAND A.G. 4 Feb., 1969 [27 March, 1968], No. 6008/69. Headings B3B and B3T. A nulling lathe for machining large crankshafts comprises a bed 2 carrying independently driven headstocks 31, 32, for rotating a crankshaft about its axis, work steadies 4, 5, 6 and 7 located between the head-stocks and a machining unit 8 which is traversable along the bed for effecting the machining of the respective crankpins and webs on the shaft. The machining unit, steadies and headstocks are movable along the bed by rack-and-pinion means. The machining unit is in the form of a portal type structure, on the cross-beam 83 of which is mounted a tool slide 84 carrying a rotary cutting tool 8411. The cutting tool is secured to a spindle 841 which is driven from a motor 842 and two motors 843 and 844 effect displacement of the tool slide by way of a rack-and-pinion 831, 845, the motor 843 providing a reciprocating feed movement of the tool slide while the motor 844 controls the tool slide in dependence on the position of a crank-pin. A further motor 846 is connected to the spindle 841 by way of gearing (not shown) to effect positioning of the spindle and to control it during the machining of the crank-pin 94, the cutter 8411 effecting a reciprocatory motion and moving in an orbital path when machining the crank-pins, the motors 844 and 846 being in-operative when the cutter is machining the crank-shaft journals. A control mechanism is attached to the headstock 32 and driven thereby to control the operation of the motors 844, 846. The control mechanism, Fig. 4 (not shown), is in the form of a disc member having a diametral "T" slot and which is driven from the headstock spindle, a bolt member being clampable in the "T"-slot to a position corresponding to the crank throw, the disc being angularly displaceable to permit alignment of the bolt member with the crank. Horizontal to vertical slotted members engage with the bolt so that rotation of the bolt with the disc effects horizontal and vertical movement of the slotted members which actuate counting devices which control the operation of the motors 844, 846 and hence the tool slide. A conveyer 25 is provided beneath the bed to effect the removal of the cuttings produced during machining.