DE1638108A1 - Contactless limit switch - Google Patents

Description

BAFI company
Raimund Finsterhölzl
798 Ravensburg

Contactless limit switch

The invention relates to the formation of limit switches for wegabhänlgen triggering of switching processes, one or more stroadurohfießen field M plates, as well as one or more magnets, are arranged to be movable relative to each other to generate electronic control pulses.

It is known that such contactless switches have opposite those with mechanical contacts have particularly advantageous properties * shafts, especially bounce-free contact, long service life » Constant transition resistance, insensitivity to Moisture and fouling, high switching frequency and low actuation force.

These properties are particularly important for limit switches, whereby the following additional conditions are also made: reproducibility dee switching point, high switching accuracy, stop speed regardless of the actuation of the holding plunger ♦

The object of the invention is now to create end stops » which have the properties of the well-known contactless so-holders and, in addition, the last-mentioned conditions

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fulfill. Firing geasUI becomes the "ImI" a "contactless" * death switch from the species discussed at the beginning, it is revealed that AbJ dl Field plate la Bereloh a · magnetic field is arranged, the ·· « Diohte and / or position to the field plate by an externally movable Bleaent or duroh the BetitigungestöSal in selectable orenzen Changeable 1st.

With this principle it is aOglioh to meet the mentioned demands meet, depending on the specific structural and functional conditions at hand, various designs according to the invention. Guides of the contactless limit switch are provided.

These basic examples of the realization of the Srfindungsprlnzipes are described based on the drawings below, in which in the one a 1 to 6 In each case a switch soheaatlsoh 1 "longitudinal section 1st and dia mutually corresponding TeI ₁ Ia übereinatlseende Besugsselohea received.

The switch housing is made of plastic old 1, the actuation »- ram old 2, the field plate ait 3 and the Haw · for housing the amplifier electronics alt * t called.

Fig. I shows a contactless limit switch, in which ia Housing 1, the penient magnet 5 ait the pole pieces 6 and the Field plate 3 are permanently installed. Actuator 2 is old

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clnea Kurssohlu0bleoh 7 provided, which against a spring 8 ·>
in Biohtung pole shoes 6 movable lit

Mode of action:

In the shown Buhetuetend of the switch · is the field plate 3 ▼ on magnetic lines bit of a certain diameter thrown through, whereby see a certain resistance value in the field plate. Ub generate a switching pulse sa, the St (SBeI 2 das KurssohluBbieoh 7 in Riohtung pole shoe · 6 moved. This will the magnetic field is shifted into the course shludbleeh 7, whereby a Masisjua at a touch swisohen the poleo shoes and dea Kurssohlufibeloh is reached. In this state, the field plate kicks off the ni ^ ipigatan resistance.

This vriderstandsänderung a suitable electronics, welohe la Rough k is untegrcht, cur Erseugung in a known way over to one SohaltlBpulses Terwendet. The switching point can be set in a reproducible manner, so that a high level of stability is achieved. ^

Fig. 2 shows a contactless limit switch, in which the welohea Slidable la Qehftuse 1 guided actuating rod 2 the magnet 10 old wearing 11 polo shoes. Opposite these is in Oehäus the Vorapannaagnet 12 almost built-in, its polo shoe as Pangbleohe 13 are formed, between which the field plate 3 is inserted.

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Mode of action:

When the actuation «plunger» 2 is pressed in, the magnet 10 is in Direction of the Vorepannmagneten 12 moved. Whose catching sheet 13 eaBBeln the magnetic field lines emanating from the pole pieces 11 and pass them through the field plate 3, which increases its resistance · Since the poles of the same name of the magnets 10 and 12 are opposite, the restoring force from the field lines won so that a feather is unnecessary.

In this design, the electrical function can be reversed by reversing the polarity of one of the two magnets. In this case The force fields of the two magnets cancel each other when they approach each other and the resistance in the field plate becomes smaller.

The switching accuracy can here by installing τοη two or several magnet systems with 'field plates in connection with an electronic comparison circuit increased'.

e ^ ⁰ - Di · Fig. 3 shows a brührunge ^ contact loeen Sohalter, in which the pre-tensioning magnet 15 with the pole pieces and the field plate 3 are permanently installed in the housing 1. Here, too, the polo shoes carry catch sheets 17 »which are arranged on an end-face outer wall of the housing.

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Mode of action:

In this embodiment, the change in resistance in the field plate 3 is achieved in that a magnet 18 is outside the housing is moved past in the direction of the arrow "P". Through the catch plates 17, the magnetic field is compressed in the area of the Field plate 3 and increases its resistance. Since there is no mechanical Wear and tear is possible, this limit switch has a practically unlimited service life.

If the polarity of one of the magnets 15 or 18 is reversed, a reverse electrical effect occurs, as described in connection with FIG. 2. In this case, when switching, the magnet 18 is moved in the direction of the arrow "P ¹ ".

In the present embodiment, instead of the magnet 18, a short circuit lead could also be used, in which case the function the arrangement of Fig. 1 would be achieved.

Fig. Jf shows a contactless limit switch with snap action. The magnet 20 with the pole piece 21 is permanently installed in the housing 1. Opposite the pole piece is a field plate carrier 22 arranged with the field plate 3, and a stop 23 for a rocker 24 is also provided. This is on a cutting edge 25 of the Poleohuhs 21 stored and has the stop 26.

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The plunger 2 actuating the rocker is in a guide position 27 out and acts via a Naohsohubfeder 28 on a pressure pin 29 a, which is supported on the rocker 2 * f.

Mode of action:

In the rest position shown, the rocker 2 * f is activated by the magnet 20 held at the stop 23, the other rocker leg pending on the pressure pin 29. Will now trigger a switching impulse a the actuation plunger 2 moves in the direction of the rocker, so the spring 28 is initially tensioned until the spring force overcomes the pest holding force of the magnet, whereupon sioh suddenly pulls the rocker loose from stop 23 and changes its position in relation to the field plate.

Since the rocker 24 is traversed by the magnetic field, results from their movement causes an abrupt change in resistance in the base plate 3, which sioh very beneficial for controlling electronic Circuits can be used

Sin particular advantage of this design is that also a safe hold-up behavior when the plunger is actuated without the bottom is guaranteed, because the so-called stopping point has been adhered to exactly

will. In addition, any Transmission ratios between the movement of the ram and the rocker can be reached.

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Xa Heu * is dl * old 30 designated electronics with a printed circuit board 31 housed · which is directly connected to the field plate is.

IAe Pig. 5 Selgt a contact bathroom switch, in which an old de «actuating tube 2 connected magnet 32 old poI-udhuhen 33 la housing is guided displaceably and by which the spring y * is held in position. The pole pieces 33 are only guided towards the seed on a small air gap 35, whereby at this point a high concentration of the magnetic flux is achieved.

Wiricungsweir *:

When the StOAsI 2 is actuated or when the magnet 32 is moved against the field plate 3, the latter tauohts into the air gap 35, whereby the resistance in the field plate changes. Duroh the high magnetic field wires la air gap is the one in the field plate Reliable resistance caused also great, which sloh on the Triggering of the stopping impulse and the stopping accuracy favorable rlrkt.

Xa FIg ₈ 6 1st SiA taontaktloeer Bodsohalter geseigt »whose holding point is adjustable · Sa for this purpose one or more magnets · 37 · 38 are arranged on a turntable 39, which is stored in the housing 1 and can be adjusted from the outside. The Asr magnets 37 »38 are again provided with an air gap ko .

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The field plate 3 sits on a concentric to the turntable Shaft 41, which e.g. by a toothed segment 42 via the angle lever 43 and a pressure pin 44 can be rotated by the plunger 2, The stop movement of the plunger takes place against a return spring 45, which when returned to the rest position shown another return spring 46 tensions. This can also be used as a connection line between the field plate and the electronics.

Effectively:

When the plunger 2 is pressed in, the angle lever 43 follows the plunger movement, since it is moved by the pretensioned spring 46 over the parts 41 ₁ 42. The field plate dips into the air gap 40 of the magnet 38 and changes its resistance value, which triggers the circuit. The switching point can be set by turning the disk 39, which can be an advantage with a limit switch «

The design of the switch according to Fig. 6 also enables use as an Orenzwertgeber between plus and minus tolerances, depending on the deflection of button 2, the field plate then dips into one of 37 or the other 38 magnets and generates pulses, which can be used, for example, for sorting out during the surface inspection of workpieces.

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Claims (2)

Plrea BAPI Balaund PinsterhölBl 79Θ Bareneburg 9- Claims «J Contactless limit switch sum path-dependent. Aue solving switching processes, with the generation of electronic control impulses of the resistance of one or more strobe-flowed Peldpletten by which a magnetic field can be changed, in that the field plate is arranged in the area of a magnetic field * is whose density and / or position to the field plate duroh an externally movable element or through the actuation shaft is τβränderbar in selectable Qrensen. 2. Limit switch according to claim 1, characterized in that im Housing a magnet with a pole piece is provided, in which the field plate is firmly inserted and its magnet connectors duroh one in the direction of the pole shoe against spring pin movable Kurssohluableoh is reprehensible. 3 · Limit switch according to umapsqush i, thereby g @ k @ mz @ i © ii & ® &, ümB Oehäuse a »^ w ^ & Pangbleoh containing the field plate is permanently installed, Welctem ®ln üm? Oh & © n StISBeI movable magnet opposite poles arranged File 5028 (a) - 2 - 0098 3 3/0617 BAO ORIGINAL 1538108 J * · limit switch according to claim 1, characterized in that dad im OehMuse «Magnet old Pangbleoh contained in the field plate is permanently installed, while outside the housing a transverse c: τ is arranged longitudinally movable magnet. 5 · limit switch according to claim 1, characterized in that ae Pole shoe of the magnet a Sohaltwlppe is mounted, which lsi Magnetic field is movable relative to the field plate and through the Magnet is held in position, whereby the actuation * - StMeI SlSJi is supported on the rocker via a Maehhubfeder, wel- • ϋ · is set so that the rocker is imprinted close to StMeI is torn loose by the spring force το «magnet. 6 · Limit switch according to claim 1, since & tiF & si characterized in that in Oehättse a magnet old F © 2,8äiÄ © n is guided displaceably through the plunger against spring action, the pole shoes being brought together except for a small air gap, in which the field plate when the Stöflels immerses. ?, Badaelw £ tojF narä mmpmioh ? characterized in that aiaf wm ün3en adjustable turntable a magnet bit air » _$ and- that di @ on a zmr turntable anfe @ rdnete field plate for Ausld ^ iag Qm & Ai # StOeelbswbewegung in the air -;.: v ^ ' ^: -. become kami «whereby for the transmission it ^ Sohaltbeüigung of the stem on the field plate a translation Proceed along SSW 1st. »St W 009833/0617 BATH ORIGINAL