SE518086C2

SE518086C2 - Measuring distance between two press rolls, using cooperating reluctance principle transmitter and magnetic reference element associated with both rolls

Info

Publication number: SE518086C2
Application number: SE9802007A
Authority: SE
Inventors: Bengt Aakerblom
Original assignee: Daprox Ab
Priority date: 1998-06-05
Filing date: 1998-06-05
Publication date: 2002-08-27
Also published as: SE9802007D0; SE9802007L

Abstract

A transmitter (6) operating according to the reluctance principle is radially positioned relative to one roll (1) and cooperates with a magnetic reference element (7) radially positioned relative to the other roll (2). A method for measuring the distance between two cooperating rolls is carried out using a transmitter operating according to the reluctance principle. The transmitter is in a radial position relative to the first roll and takes measurements in relation to a reference element made from magnetic material and radially positioned on the second roll. An Independent claim is also included for the measuring system.

Description

25 | . - Q u 518 086 2 En förbättrad anordning uppnås enligt definitionen i patentkrav 5. Genom att anord- na ett referenselement nära den ena valsens mantelyta och placera en givare arbe- tande enligt reluktansprincipen vid den undre valsen kan mätavståndet göras litet, samtidigt som inverkan av lagerglapp och temperaturutvidgning kan kontrolleras. 25 | . An improved device is achieved as defined in claim 5. By arranging a reference element near the mantle surface of one roller and placing a sensor operating according to the reluctance principle at the lower roller, the measuring distance can be made small, at the same time as the effect of bearing gap and temperature expansion can be controlled.

Ytterligare fördelar och särdrag hos uppfinningen framgår av efterföljande beskriv- ning.Further advantages and features of the invention will become apparent from the following description.

Figgbeskrivning Uppﬁnningen förklaras i det följande närmare med hjälp av på bifogade ritning vi- sade utföringsexempel, där: ﬁg. 1 visar en sidvy av ett arrangemang enligt uppfinningen, ﬁg. 2 visar en ändvy av arrangemanget i ﬁg. 1, fig. 3 visar i förstorad skala en detalj i ﬁg. l, och ﬁg. 4 visar en variant av utförandet i ﬁg. 3. I Beskrivning av utföringsforrner Enligt ﬁg. 1 och 2 samverkar en första vals 1 och en andra vals 2 med varandra på ett visst inbördes avstånd. Valsamas axlar 3 och 4 är härvid monterade i ej närmare visade lager i ett lämpligt stativ. Mellan valsama behandlas en bana av ett ämne 5, t.ex. papper, plast, aluminium, koppar eller stål.Fig. Description The invention is explained in more detail below with the aid of exemplary embodiments shown in the accompanying drawing, in which: ﬁ g. 1 shows a side view of an arrangement according to the invention, ﬁ g. 2 shows an end view of the arrangement in ﬁ g. 1, Fig. 3 shows on an enlarged scale a detail in ﬁ g. l, and ﬁ g. 4 shows a variant of the embodiment in ﬁ g. 3. I Description of embodiments According to ﬁ g. 1 and 2, a first roller 1 and a second roller 2 cooperate with each other at a certain mutual distance. The shafts 3 and 4 of the rollers are in this case mounted in bearings not shown in more detail in a suitable stand. Between the rollers a web of a substance 5 is treated, e.g. paper, plastic, aluminum, copper or steel.

Vid åtminstone den ena gaveln på den första valsen 1 firms anordnat en givare 6 för mätning av avståndet mellan valsama. Denna givare är en positionsgivare och arbe- tar enligt reluktansprincipen. Givare av denna typ är välkända och har beskrivits i t.ex. svenska patentet 7904903-7, varför någon detaljerad beskrivning av givarens arbetssätt och uppbyggnad inte erfordras i detta sammanhang. Givaren 6 samverkar med ett på den andra valsen 2 anordnat första magnetiskt (magnetiskt ledande) refe- _ renselement 7, som i detta fall är ringformigt och är fástat på gaveln på den andra 10 15 20 25 30 518 086 3 valsen 2. Diametern på denna ring är lärnpligen högst lika med diametern på den andra valsen 2.At at least one end of the first roller 1 a sensor 6 is arranged for measuring the distance between the rollers. This sensor is a position sensor and works according to the reluctance principle. Sensors of this type are well known and have been described in e.g. Swedish patent 7904903-7, which is why no detailed description of the donor's working method and structure is required in this context. The sensor 6 cooperates with a first magnetic (magnetically conductive) reference element 7 arranged on the second roller 2, which in this case is annular and is attached to the end wall of the second roller 2. The diameter of this ring is mandatory at most equal to the diameter of the second roller 2.

Givaren 6 befinner sig lämpligen radiellt lägesbestämt innanför mantelytan på den första valsen 1 och skyddas av ett på den första valsen 1 anordnat omagnetiskt refe- renselement 8. Detta omagnetiska referenselement 8 är ringformigt och har lämpli- gen en diameter som är högst lika med diametern på den första valsen 1. En sådan placering och utformning av referenselementen 7 och 8 medför att utrymmet mellan valsama 1 och 2 inte blockeras i sidled.The sensor 6 is suitably located radially positioned inside the circumferential surface of the first roller 1 and is protected by a non-magnetic reference element 8 arranged on the first roller 1. This non-magnetic reference element 8 is annular and suitably has a diameter which is at most equal to the diameter of the first roller 1. Such a placement and design of the reference elements 7 and 8 means that the space between the rollers 1 and 2 is not blocked laterally.

Givaren 6 är i det visade utförandet i ﬁg. 1 - 3 dubbelsidig och mäter även mot ett andra magnetískt referenselement 9 på den första valsen 1, placerat radiellt innanför givaren 6. Även referenselementet 9 är i detta fall ringfonnigt. Avståndet mellan valsarna l och 2 blir således i detta fall en fimktion av avståndet mellan de magne- tiska referenselementen 7 och 9.The sensor 6 is in the embodiment shown in ﬁ g. 1 - 3 double-sided and also measures against a second magnetic reference element 9 on the first roller 1, placed radially inside the sensor 6. The reference element 9 is in this case also ring-shaped. The distance between the rollers 1 and 2 thus becomes in this case a function of the distance between the magnetic reference elements 7 and 9.

Genom att mätningen således sker nära mantelytoma på valsama 1 och 2 kan vals- avståndet mätas med god precision. Genom att enligt ﬁg. 1 mäta vid båda valsän- darna kan mätnoggrannheten ökas och eventuella snedställningar kan regleras.Because the measurement thus takes place close to the mantle surfaces on rollers 1 and 2, the roll distance can be measured with good precision. By according to ﬁ g. 1 measuring at both roll ends, the measuring accuracy can be increased and any skew can be regulated.

Ett altemativt utförande framgår av ﬁg. 4, där den dubbelsidiga givaren 6 har bytts ut mot en enkelsidig givare 6a. Liksom tidigare ﬁrms ett magnetiskt referenselement 7 på den andra valsen 2. Givaren 6a lägesbestäms i detta fall i radiell led relativt den första valsen 1 genom att givaren 6a på känt sätt lägesﬁxeras mot det omagnetiska referenslementet 8 med hjälp av en gaskudde 10 mellan givaren och referensele- mentet. Avståndet mellan valsarna 1 och 2 blir således i detta fall en funktion av av- ståndet mellan referenselementen 7 och 8.An alternative embodiment is shown in ﬁ g. 4, where the double-sided sensor 6 has been replaced by a single-sided sensor 6a. As before, a magnetic reference element 7 is placed on the second roller 2. The sensor 6a is in this case determined in radial direction relative to the first roller 1 by positioning the sensor 6a in a known manner against the non-magnetic reference element 8 by means of a gas cushion 10 between the sensor and the reference belt. - meant. The distance between the rollers 1 and 2 thus becomes in this case a function of the distance between the reference elements 7 and 8.

För att öka mâtprecisionen kan givarna 6 och 6a lämpligen i sina mot referensele- menten 8 och 9 vända ändar ha samma krökning som referenselementen. 518 086 Det omagnetiska referenselementet 8 bör vara så tunt som möjligt för att inte öka mätavståndet mer än nödvändigt. Materialet i detta referenselement, som också fun- gerar såsom ett skydd for givaren, kan t.ex. vara Syrafast stål, titan, aluminium, kop- par eller plast.In order to increase the measuring precision, the sensors 6 and 6a can suitably have the same curvature as the reference elements at their ends facing the reference elements 8 and 9. 518 086 The non-magnetic reference element 8 should be as thin as possible so as not to increase the measuring distance more than necessary. The material in this reference element, which also functions as a protection for the sensor, can e.g. be acid-resistant steel, titanium, aluminum, copper or plastic.

I de fall då det inte föreligger något behov av ett fritt utrymme mellan valsama i sidled är det naturligtvis möjligt att montera givaren och referenselementet på den andra valsen 2 närmare varandra än vad som visats i exemplet på ritningen.In cases where there is no need for a free space between the rollers laterally, it is of course possible to mount the sensor and the reference element on the second roller 2 closer to each other than what is shown in the example in the drawing.

Claims

10 15 20 25 30 518 086 5 Patent claims

A method of measuring the distance between a first roller (1) and a second roller (2) cooperating therewith, measuring being performed by means of a non-rotating sensor (6,6a) which is placed radially positioned relative to the first roller (1) and measures against a radially positioned first reference element (7) of magnetic material at the second roller (2), characterized in that the sensor (6,6a) operates according to the reluctance principle, that the measurement is performed against a mounted on the second roller (2) and together with this rotating first reference element (7), and that the measurement is made through a non-magnetic element (8) arranged on the first roller (1) radially outside the sensor and rotating together with the roller.

Method according to claim 1, characterized in that the sensor (6a) is placed radially positioned relative to the first roller (1) by means of a gas cushion (10) against the non-magnetic element (8) designed as a reference element.

Method according to claim 1, characterized in that measurement takes place with a double-sided sensor (6) also against a position-determined second magnetic reference element (9) located radially inside the sensor, arranged on the first roller (1).

Method according to one of Claims 1 to 3, characterized in that measurement takes place at at least one end of the rollers.

Device for measuring the distance between a first roller (1) and a second roller (2) cooperating therewith, a sensor (6,6a) being arranged at the first roller (1), radially positioned relative thereto, and is arranged to measure against a radially positioned first reference element (7) of magnetic material arranged at the second roller, characterized in that the sensor (6, 6a) operates according to the reluctance principle, that the first reference element (7) is annular and is fixedly mounted on a gable on the second roller (2) and rotates together therewith, and that the first roller (1) is now provided with a radial outside the sensor, on the roller fixedly arranged annular, non-magnetic element (8) through which the sensor can measure against the first reference element (7).

Device according to Claim 5, characterized in that the first roller (1) is provided with a second reference element (9) of magnetic material fixedly arranged radially inside the sensor, and in that the sensor (6) is double-sided, for measuring against each of the two magnetic reference elements (7,9).

Device according to claim 5, characterized in that the sensor (6a) is radially positioned relative to the first roller (1) by means of a gas cushion (10) against the non-magnetic element (8).

Device according to one of Claims 5 to 7, characterized in that the circumferential surface of at least one roller (1,2) has a diameter which is greater than or equal to the diameter of the annular elements (7,8,9 ).