FR2466089A3 - DEMAGNETIZATION DEVICE - Google Patents

Abstract

THE INVENTION CONCERNS A DEMAGNETIZING DEVICE OF THE TYPE A DISCHARGE OF A CONDENSER. ACCORDING TO THE INVENTION, IT INCLUDES FIRST AND SECOND INDUCTORS 2 AND 3, ARRANGED ALONG THE SAME AXIS, AND A GUIDANCE 9 THROUGH WHICH A PART 10 TO BE DEMAGNETIZED IS INTRODUCED IN A PRE-ESTABLISHED POSITION BETWEEN THE FIRST AND SECOND INDUCERS. THE INVENTION APPLIES IN PARTICULAR TO THE DEMAGNETIZATION OF BEARINGS OR BALL BEARINGS.

Description

The present invention relates to a device

demagnetization.

  In particular, the present invention relates to a demagnetization device of the type with discharge of a capacitor, that is to say of the type comprising a capacitor that can be discharged into an inductor in order to produce free and damped oscillations of the current. flowing in the inductor. The part to be demagnetized is arranged so that the magnetic field produced by the inductor acts on it, in order to demagnetize it. Although these demagnetizing devices have considerable advantages, from the point of view of design, with respect to the devices according to the prior art comprising only one inductor, from the point of view of structure,

  they still have some disadvantages.

  In particular, when the part to be demagnetized consists of a number of parts that can protect each other or form screen against each other, such as in a mounted bearing, it is important that the direction of demagnetization field so that it diminishes the effects of this protection; in particular, in the case of a bearing, this direction must be coaxial with the direction of the magnetic field present in the bearing, in order to prevent the external path of the bearing from forming

  partially screen in front of the internal path or the balls.

  In known degaussing devices, the inductor is generally of the solenoid type, and in order to meet the specific requirements of the

  direction of the magnetic field, it is necessary to introduce

  the bearing in the inductor, its axis coinciding with that of the inductor. Therefore, it is necessary to use an appropriate transport device

  to properly demagnetize each pallet.

  In the case where the dimensions of the parts to be demagnetized are included over a wide range, it is necessary to provide, for each group of parts to be demagnetized having approximately the same dimensions, a suitable inductor in which the part must be slid, and whose dimensions must match those of the room. As a result, the known degaussing devices require considerable expense

of equipment.

  The present invention relates to a demagnetization device of the type with discharge of a capacitor, which device makes it possible to eliminate the disadvantages

  above mentioned structure of known devices.

  According to the present invention there is provided a capacitor discharge type demagnetizing device which comprises first and second inductors arranged along the same axis, and a guide by means of which

  a body to be demagnetized is introduced in the pre-position

  established between the first and second inductors.

  The invention will be better understood and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatory text which will follow with reference to the appended schematic drawing given solely by way of example illustrating an embodiment of the invention and in which: the single figure shows schematically and in perspective a degaussing device constructed according to

  the teachings of the present invention.

  In the drawing, reference numeral 1 generally designates a portion of a capacitor discharge type demagnetization device, of which only one pair

  Solenoid type inductors 2 and 3 are shown.

  In particular, the inductors 2 and 3 are arranged along the same axis inside respective support bodies 4, 5 with means (not shown) for adjusting, in the axial direction, their reciprocal distance. From the electrical point of view, the inductors 2 and 3 have terminals facing each other and connected to each other by means of a conductive wire 7 forming a loop, and opposite terminals which are connected, in a represented way , to a capacitor

  by a switching means (not shown).

  In the space formed between the inductors 2 and 3 is disposed a guide 9 inclined relative to the horizontal plane, on which can be advanced a part to demagnetize. In the present example, this part to be demagnetized is a ball bearing 10 substantially comprising an inner channel 11 and an outer channel 12 where a number of balls 13 are housed. The bearing 10 can roll along the guide 9, formed of an element C-shaped, made of a material that is not sensitive to magnetic fields to guide

correctly the bearing 10.

  In the space between the inductors 2 and 3 and below the guide 9 is mounted a proximity sensor device 15 which can emit an electrical signal by respective connection cables 16 and 17 when a bearing 10 passes on the guide 9 in the space between the inductors 2 and 3. Finally, downstream of the inductors 2 and 3 is mounted a stop device 19, for example a pneumatic piston which, in response to the reception of a control signal, places a bar 20 along the path of the movement of the bearing 10 in the

  guide 9 to temporarily block the bearing.

between inductors 2 and 3.

  Finally, each bearing 10 is brought to the top of the guide 9 by means of a vertical conveyor belt provided with a number of support planes 23 having a first end rotatable about a support pin 24 carried by the belt 22 and a second

  end connected to the band 22 by springs 25.

  The operation of the degaussing device is as follows: Each bearing 10 is brought to a pre-established recurrence frequency, according to the speed of the belt or belt 22, and according to the distance between two consecutive planes 23, at the top of the guide 9, it rolls along the guide 9 and enters the space between the inductors 2 and 3 o it validates the sensor device 15. The latter, by a not shown processing circuit, acts on the switching means mentioned above, so to connect the inductors 2 and 3 to the capacitor, which has previously been charged. Consequently, the magnetic field produced by the switching means alternately takes positive and negative values whose amplitude is amortized exponentially, thus producing a cycle of free and damped oscillations of which

  the duration is a few tens of milliseconds.

  If the initial amplitude of the magnetic field is sufficient to give rise to the saturation of the material forming the rolling bearing 10, the latter is demagnetized during its passage between the inductors 2 and 3, whose demagnetization action is correct because the field qu 'they produce can cross, in the axial direction, the tracks

11 and 12 and the balls 13.

  In cases where the dimensions of the bearing 10 are such that more than one cycle of oscillations of the demagnetizing field is required, the stop device 19 is actuated and, by means of the bar 20, it keeps the bearing 10 between inductors 2 and 3 during the time required for each capacitor to recharge, so that the required number of demagnetization cycles can be

to be produced.

  It can be noted, at the analysis of the characteristics

  of the present invention, that the demagnetizing device

  sation makes it possible to reach the objects mentioned above. In fact, the lines of force of the magnetic field in the zone between the inductors 2 and 3 take an axial direction with respect to the bearing which is thus in the best conditions for

be properly demagnetized.

  As the distance between the inductors 2 and 3 is adjustable, it is possible to adjust each time this distance according to the dimensions of the part to be demagnetized, so a single degaussing device of the type described above can be used for parts having

  dimensions very different from each other.

  For example, the guide 9 can be configured each time to better correspond to the structure of the part to demagnetize, and possibly it can even be replaced by a conveyor belt. Moreover, the inductors 2 and 3 which, in the drawing, are illustrated as being connected in series, could also be connected in parallel, provided that the respective magnetic forces are in phase, and could also be wound on a magnetic core for example made

ferrite.

  Of course, the invention is not limited to the embodiment described and shown which has been given by way of example. In particular, it includes all the means constituting technical equivalents of the means described and their combinations if they are executed according to its spirit and put

  implemented in the context of protection as claimed.

Claims (9)

R E V E N D I C A T I 0 N S   1. Device for degaussing the discharge type of a capacitor, characterized in that it comprises first and second inductors (2 and 3) arranged along the same axis, and a guide (9) by means of which a part (10) to demagnetize is introduced into a pre-established position between said first and second inductors. 2. Device according to claim 1, characterized in that it comprises a detector device (15) capable of detecting the presence of the aforementioned part in the pre-established position, said detector device for producing an oscillating magnetic field damped by said inductor.   3. Device according to any one of the claims   1 or 2, characterized in that the aforesaid guide is configured as an inclined plane and in that the workpiece   aforementioned is brought to the top of said guide.   4. Device according to any one of the claims   preceding, characterized in that it comprises a mechanical stop means (19, 20) for stopping the aforementioned part, being able to maintain said piece at its position   pre-established for a time of a pre-established duration.   5. Device according to claim 4, characterized in that the period of time has a sufficient duration to allow the aforementioned inductor to emit at least   a pair of cycles of oscillations of the magnetic field.   6. Device according to any one of the claims   4 or 5, characterized in that the mechanical means of stopping   aforementioned comprises a pneumatic piston (19).   7. Device according to any one of the claims   characterized in that it comprises means for adjusting the relative position between the first and second inductor mentioned above.   8. Device according to any one of the claims   preceding, characterized in that the aforementioned inductors 72466089   are wound on a magnetic core.   9. Device according to claim 8, characterized   in that the aforementioned magnetic core is made of ferrite.