FR2697712A1 - Induction heating device. - Google Patents

Abstract

The invention relates to an induction heating device. In this device for carrying out inductive heating and subsequent quenching to obtain hardening of the crank pin surfaces, directly in reciprocal abutment, of a crankshaft using two inductors arranged in diametrically opposed positions near the part to be treated and one of which is respectively associated with one of the two crankpins and has a width less than the passage width of a crankpin and whose arc-shaped active surface has at most a length equal to that of the overlapping arcs of the crankpins , the width (b) of the inductors (12) is greater than the width (e) of the back (11c) of the crankpin. Application in particular to the surface hardening of crankshafts.

Description

The invention relates to a device for performing inductive heating

  and a subsequent quenching to obtain the hardening of the crank surfaces, directly abutting each other, of a crankshaft with the aid of two inductors arranged in diametrically opposite positions near the workpiece and one of which is associated respectively with one of the two crankpins and has a width less than the passage width of a crank pin and whose active surface of arcuate shape has a maximum length equal to that of the overlapping arches

crank pins.

  A device having the characteristics of the type indicated above is known from the German patent application 36 13 909 C1 However, this device has the disadvantage that it does not achieve sufficient hardening of the junction area between the surface of the crankpin and the flange, that is to say what we

call the leave zone.

  In the device known from the German patent application 40 01 887 C 2, unlike the document cited first, the inductors are not located on opposite sides, but on the same side To avoid a reciprocal influence of the inductors, this In addition, here there is a lack of space due to the close proximity of inductors and

  the comparatively small space that is available.

  The object of the invention is to improve an electro-induction heating device of the type indicated, so that, in spite of the narrow spaces, sufficient hardening is achieved even in the grooves, that is to say the junctions, in the form of

  leaves, between the surface of a crank pin and the adjacent crank flange on the one hand and with the adjacent crank pin on the other hand.

  To solve this problem it is provided according to the invention, in the device of the type indicated, that the width of the inductors is greater than the width of the back of the crankpin This characteristic ensures effective heating also in the area of the grooves connecting to the crankpin surface. Other features and benefits of the

  present invention will emerge from the description given

  BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents the general view of the induction hardening device for crankshafts, comprising an open inductor situated in its rest position, in the ready state to receive crank pins which must be cured of the surface; Figure 2 shows a partial view of the lower part of the hardening device equipped with the inductor closed in its working position on the crank pin of a crankshaft; Figure 3 shows a view of the contiguous crankpin, equipped with inductors separated reciprocally by a greater distance; Figure 4 shows a cross section associated with Figure 3; Figure 5 is a view of the contiguous crank pins, the inductors being shown in the working position, being separated by their smaller distance; and Figure 6 shows the cross section

associated with Figure 5.

  In the figures, the same elements have been designated

  by the same reference numbers.

  The induction device generally designated by the reference numeral 1 is mounted on a cross member 3 so as to be pivotable, under the action of a pneumatic or hydraulic drive unit 2, between an open position (rest) (Figure 1) and a closed position

  (work) (Figure 2) The crossbar 3 is mounted oscil-

  using a parallelogram guidance system 4.

  The cross-member 3 is guided in such a manner as to be vertically displaceable by means of a guide bar. The weight of the guide rod 5 is compensated by a counterweight 6, which is connected to the guide bar 5 via

  a cable 9 traveling on wheels 7, 8.

  A crankshaft 10 having contiguous crank pins 11a, 11b is brought into the working position visible in FIG. 2, by raising or lowering the inductive hardening device or the crankshaft 10. The induction hardening device comprises two inductors 12 placed in diametrically opposite positions near the workpiece, and a spraying device for quenching 13 The connectors 14 serve to supply cooling water to the two inductors 12, and the quenching liquid is sent via the supply line 15 to the device 12 for spraying the quench liquid, as can be seen more clearly in FIG. 2 The crankshaft 10

  is supported in its center by rollers 16.

  Two crank pins 11a, 11b, which are situated between flanges 18, of a crankshaft 10 are directly contiguous in accordance with FIG. 3 The insertion width S is chosen greater than the width e of the back of the crankpin. two inductors 12 mounted in diametrically opposite positions near the crankshaft 10 is smaller than the insertion width s, and is greater than

the width e of the back of the crank pin.

  In order that the two inductors 12 do not touch each other in the position visible in FIGS. 5 and 6, in which they are the closest to each other, the length 1 of their arcuate active surface 19 must be equal to at most to the length a of the overlapping arc 20 of the crank pins 11a, 11b, as shown

  better figure 4 We can have at most a = 1.

Claims (1)

CLAIM   Device for performing inductive heating and subsequent quenching to achieve hardening of the crank surfaces (11a, 11b), directly abutting each other, of a crankshaft (10) with two inductors (12) in positions diametrically opposed to the workpiece and one of which is associated respectively with one of the two crankpins and has a width less than the passage width of a crank pin and whose active surface of arcuate shape has a maximum length equal to that of the recovery arches   crank pins, characterized in that the width (b) of the inductors (12) is greater than the width (e) of the back (1 uc) of the crankpin.