FR2669418A1 - Device for measuring displacement of an object - Google Patents

Device for measuring displacement of an object Download PDF

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Publication number
FR2669418A1
FR2669418A1 FR9014413A FR9014413A FR2669418A1 FR 2669418 A1 FR2669418 A1 FR 2669418A1 FR 9014413 A FR9014413 A FR 9014413A FR 9014413 A FR9014413 A FR 9014413A FR 2669418 A1 FR2669418 A1 FR 2669418A1
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FR
France
Prior art keywords
coil
piece
sheet
guide means
oscillating circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
FR9014413A
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French (fr)
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FR2669418B1 (en
Inventor
Derrey Thierry
Reghem Pascal
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HAVRE LEPII UNIVERSITE
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HAVRE LEPII UNIVERSITE
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Priority to FR9014413A priority Critical patent/FR2669418B1/en
Publication of FR2669418A1 publication Critical patent/FR2669418A1/en
Application granted granted Critical
Publication of FR2669418B1 publication Critical patent/FR2669418B1/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D24/00—Special deep-drawing arrangements in, or in connection with, presses
    • B21D24/04—Blank holders; Mounting means therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/003—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring position, not involving coordinate determination
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
    • G01D5/2013—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by a movable ferromagnetic element, e.g. a core

Abstract

It includes a piece (1, 15) made of a material with a high magnetic permeability, a coil (4), a mechanical guide means (10) and an oscillating (resonant) circuit (11) including the coil (4), the piece of ferromagnetic material (1, 15) being solidly attached to the object (1, 14) and held by the guide means (10) parallel to the coil (4), so that the displacement of the said piece (1, 15) alters the self-inductance of the coil (4) and the oscillation (resonant) frequency of the oscillating circuit (11).

Description

La présente invention concerne un dispositif de mesure de déplacement d'un objet, destiné notamment à la mesure de déplacement des flans d'une pièce en cours d'emboutissage. The present invention relates to a device for measuring the displacement of an object, intended in particular for measuring the displacement of the blanks of a part being stamped.

Les dispositifs connus à ce jour, de type à soudure de fil témoin ou traçage de contours sont d'une manipulation difficile et d'une précision limitée. The devices known to date, of the type of witness wire welding or contour tracing are difficult to handle and of limited precision.

La présente invention entend remédier à ces inconvénients par l'utilisation d'un matériau ferromagnétique fixé à 11 objet en déplacement et placé de la même manière qu'un entrefer d'électro-aimant, entre une bobine conductrice et un moyen de guidage maintenant la distance entre le matériau magnétique et la bobine, la variation du champ magnétique dépendant de la position de cet entrefer étant perçue par la variation de fréquence d'oscillation d'un circuit oscillant incluant ladite bobine. The present invention intends to remedy these drawbacks by the use of a ferromagnetic material fixed to the moving object and placed in the same manner as an electromagnet air gap, between a conductive coil and a guide means maintaining the distance between the magnetic material and the coil, the variation of the magnetic field depending on the position of this air gap being perceived by the variation of frequency of oscillation of an oscillating circuit including said coil.

La présente invention a ainsi pour objet un dispositif de mesure de déplacement d'un objet caractérisé en ce qu'il comporte une pièce en matériau de perméabilité magnétique élevée, une bobine, un moyen de guidage mécanique et un circuit oscillant incluant la bobine, en ce que la pièce en matériau magnétique est solidarisée à l'objet en déplacement et maintenue par le guidage parallèlement à la bobine, étant placée dans le champ magnétique créé par cette dernière de telle manière que son déplacement fait varier llauto-induction de la bobine et la fréquence d'oscillation du circuit oscillant. The present invention thus relates to a device for measuring the displacement of an object, characterized in that it comprises a piece of material of high magnetic permeability, a coil, a mechanical guide means and an oscillating circuit including the coil, in that the piece of magnetic material is secured to the moving object and held by the guide parallel to the coil, being placed in the magnetic field created by the latter in such a way that its displacement varies the self-induction of the coil and the oscillation frequency of the oscillating circuit.

Pour l'application aux presses à emboutir, l'objet et la pièce en matériau magnétique sont confondus et constitués de la tôle à emboutir, la presse à emboutir présentant des serre-flans réalisant le guidage du dispositif selon l'invention. En ce cas, le dispositif de l'invention constitue un capteur d'avalement pour presse à emboutir. For application to stamping presses, the object and the part made of magnetic material are combined and consist of the sheet metal to be stamped, the stamping press having blank clamps guiding the device according to the invention. In this case, the device of the invention constitutes a swallowing sensor for a stamping press.

Les avantages, buts et caractéristiques de la présente invention ressortiront plus clairement de la description qui va suivre, faite en regard du dessin annexé, dans un but explicatif et nullement limitatif. The advantages, aims and characteristics of the present invention will emerge more clearly from the description which follows, given with reference to the appended drawing, for explanatory purposes and in no way limiting.

Dans le dessin annexé
- la figure 1 représente une vue en coupe partielle d'une presse à emboutir et d'un dispositif selon l'invention.In the attached drawing
- Figure 1 shows a partial sectional view of a stamping press and a device according to the invention.

- la figure 2 représente une vue de dessus partielle du dispositif de la figure 1.  - Figure 2 shows a partial top view of the device of Figure 1.

- la figure 3 représente une vue partielle du dispositif après déplacement d'une tôle en cours d'emboutissage. - Figure 3 shows a partial view of the device after moving a sheet during stamping.

- la figure 4 représente une vue en coupe d'un dispositif selon l'invention adapté à la mesure de déplacement d'objets quelconques. - Figure 4 shows a sectional view of a device according to the invention suitable for measuring the displacement of any objects.

Si on se réfère à la figure 1, on voit sur cette figure une tôle à emboutir 1, un capteur 2 comportant un joint étanche 3 et une bobine 4 possédant deux liaisons électriques 5 et 6, un outil 7, un serre-flan 8, un poinçon 9, un guidage 10 mécaniquement lié au serre-flan 8, un circuit oscillant 11 incluant la bobine 4. If we refer to FIG. 1, we see on this figure a sheet metal to be stamped 1, a sensor 2 comprising a tight seal 3 and a coil 4 having two electrical connections 5 and 6, a tool 7, a blank holder 8, a punch 9, a guide 10 mechanically linked to the blank holder 8, an oscillating circuit 11 including the coil 4.

La tôle 1 est en matériau à perméabilité magnétique élevée, tandis que le joint étanche 3 et le guidage 10 possèdent une perméabilité magnétique faible. En particulier, le joint peut être en matière plastique et le guidage 10 en bronze. La bobine 4 est de forme allongée selon un axe parallèle au déplacement de la tôle. Le capteur 2 est mécaniquement lié à l'outil 7. The sheet 1 is made of a material with high magnetic permeability, while the seal 3 and the guide 10 have a low magnetic permeability. In particular, the seal may be made of plastic and the guide 10 of bronze. The coil 4 is elongated along an axis parallel to the movement of the sheet. The sensor 2 is mechanically linked to the tool 7.

Le circuit oscillant 11 est réalisé selon un schéma électrique connu et peut être remplacé par tout autre circuit oscillant de type connu. The oscillating circuit 11 is produced according to a known electrical diagram and can be replaced by any other oscillating circuit of known type.

Si on se réfère à la figure 2, on y retrouve le capteur 2, le joint étanche 3, la bobine 4 de forme allongée et ses deux liaisons électriques 5 et 6. If we refer to Figure 2, we find the sensor 2, the seal 3, the coil 4 of elongated shape and its two electrical connections 5 and 6.

Si on se réfère à la figure 3, on y retrouve la tôle à emboutir 1, le capteur 2 comportant le joint étanche 3 et la bobine 4 possédant les deux liaisons électriques 5 et 6, l'outil 7, le serre-flan 8, le poinçon 9, le guidage 10 mécaniquement lié au serre-flanc 8. If we refer to FIG. 3, we find there the sheet metal to be stamped 1, the sensor 2 comprising the watertight seal 3 and the coil 4 having the two electrical connections 5 and 6, the tool 7, the blank holder 8, the punch 9, the guide 10 mechanically linked to the side clamp 8.

Par rapport à la figure 1, seuls la tôle 1 et le poinçon 9 se sont déplacés. Compared to Figure 1, only the sheet 1 and the punch 9 have moved.

La perméabilité magnétique de la tôle 1 étant très différente de celles du guidage 1 et de l'air environnant, l'autoinduction de la bobine 4 est en relation avec la longueur de la tôle 1 qui la recouvre, selon un principe connu. The magnetic permeability of the sheet 1 being very different from that of the guide 1 and the surrounding air, the self-induction of the coil 4 is related to the length of the sheet 1 which covers it, according to a known principle.

Le circuit oscillant 11 possède une fréquence d'oscillation dépendant de l'auto-induction de la bobine 4. The oscillating circuit 11 has an oscillation frequency dependent on the self-induction of the coil 4.

En conséquence, tout déplacement de la tôle 1 parallèlement à l'axe d'élongation de la bobine 4 se traduit par une variation de la fréquence d'oscillation du circuit oscillant 11.  Consequently, any displacement of the sheet 1 parallel to the elongation axis of the coil 4 results in a variation of the frequency of oscillation of the oscillating circuit 11.

Selon une autre terminologie, la variation de longueur des matériaux de perméabilités magnétiques différentes dans le champ magnétique de la bobine fait varier la reluctance du capteur, celle-ci étant l'intégrale sur une ligne de champ magnétique des longueurs d'éléments de lignes de champs divisés par les produits des perméabilités magnétiques et des surfaces de flux. L'auto-impédance de la bobine est une relation de cette reluctance égale au carré du nombre de spires de la bobine 4 divisée par la reluctance. Pour mémoire, on peut indiquer que la fréquence d'oscillation du circuit oscillant 11 est environ proportionnelle à la racine carrée de la longueur d'air se trouvant en vis-à-vis de la bobine, quand la perméabilité magnétique de la tôle est très grande. According to another terminology, the variation in length of the materials of different magnetic permeabilities in the magnetic field of the coil makes vary the reluctance of the sensor, this being the integral on a magnetic field line of the lengths of line elements of fields divided by the products of magnetic permeabilities and flux surfaces. The coil self-impedance is a relation of this reluctance equal to the square of the number of turns of the coil 4 divided by the reluctance. As a reminder, it can be indicated that the oscillation frequency of the oscillating circuit 11 is approximately proportional to the square root of the length of air facing the coil, when the magnetic permeability of the sheet is very big.

L'utilisation du dispositif selon l'invention avec une presse à emboutir permet de faire varier la vitesse de déplacement du poinçon 6 et la pression sur le ou les serre-flans 5 en fonction du déplacement de la tôle 1. Cet asservissement permet d'éviter d'une part une trop forte pression du ou des serre-flans 5 sur la tôle 1, qui provoquerait une déchirure ou une rupture de la tôle 1, et d'autre part une trop faible pression qui provoquerait l'apparition de plis sur la tôle 1. Enfin, cet asservissement peut se faire en temps réel, au cours de l'emboutissage de la tôle 1. The use of the device according to the invention with a stamping press makes it possible to vary the speed of movement of the punch 6 and the pressure on the blank holder (s) 5 as a function of the movement of the sheet 1. This control makes it possible to avoid on the one hand too strong pressure of the blank holder (s) 5 on the sheet 1, which would cause a tear or rupture of the sheet 1, and on the other hand too low pressure which would cause the appearance of folds on sheet 1. Finally, this control can be done in real time, during the stamping of sheet 1.

Si on se réfère à la figure 4, on y voit un dispositif adapté à la mesure de déplacement d'objets quelconques. If we refer to Figure 4, we see a device suitable for measuring the displacement of any objects.

On retrouve dans cette figure le capteur 2 comportant le joint étanche 3 et la bobine 4 possédant les deux liaisons électriques 5 et 6, le guidage 10 mécaniquement lié au capteur 2, auxquels s'adjoignent un objet 14 et une pièce témoin 15 en matériau de haute perméabilité magnétique, solidarisés entre eux mécaniquement et adaptés à se déplacer parallèlement à l'axe d'élongation de la bobine 4. We find in this figure the sensor 2 comprising the seal 3 and the coil 4 having the two electrical connections 5 and 6, the guide 10 mechanically linked to the sensor 2, to which are added an object 14 and a witness piece 15 made of high magnetic permeability, mechanically joined together and adapted to move parallel to the elongation axis of the coil 4.

Par rapport à l'application présentée en regard des figures 1 à 3, l'objet 14 dont on mesure le déplacement et la pièce en matériau magnétique 15 ne sont plus confondus. Compared to the application presented with reference to Figures 1 to 3, the object 14 whose displacement is measured and the piece of magnetic material 15 are no longer confused.

Le fonctionnement du dispositif est identique à celui décrit à l'appui des figures 1 à 3.  The operation of the device is identical to that described in support of FIGS. 1 to 3.

Claims (6)

REVENDICATIONS t) Dispositif de mesure de déplacement d d'un objet, caractérisé en ce qu'il comporte une pièce (1, 15) en matériau de perméabilité magnétique élevée, une bobine (4), un moyen de guidage mécanique (10) et un circuit oscillant (11) incluant la bobine (4), en ce que la pièce de matériau ferromagnétique (1, 15) est solidarisée à l'objet (1, 14) et maintenue par le moyen de guidage (10) parallèlement à la bobine (4), de telle manière que le déplacement de ladite pièce (1, 15) fait varier l'autoinduction de la bobine (4) et la fréquence d'oscillation du circuit oscillant (11). t) Device for measuring the displacement d of an object, characterized in that it comprises a part (1, 15) made of material of high magnetic permeability, a coil (4), a mechanical guide means (10) and a oscillating circuit (11) including the coil (4), in that the piece of ferromagnetic material (1, 15) is secured to the object (1, 14) and held by the guide means (10) parallel to the coil (4), so that the movement of said part (1, 15) varies the self-induction of the coil (4) and the frequency of oscillation of the oscillating circuit (11). 2) Dispositif selon la revendication 1 caractérisé en ce que l'objet en déplacement et la pièce en matériau magnétique sont confondus.2) Device according to claim 1 characterized in that the moving object and the piece of magnetic material are combined. 3) Dispositif selon la revendication 2 caractérisé en ce qu'il est incorporé à une presse à emboutir, le moyen de guidage (10) étant solidarisé à un serre-flanc (8) et le capteur (2) à un outil (7) de presse à emboutir, l'objet et la pièce en matériau ferromagnétique étant constitués d'une tôle à emboutir (1). 3) Device according to claim 2 characterized in that it is incorporated in a stamping press, the guide means (10) being secured to a clamp (8) and the sensor (2) to a tool (7) stamping press, the object and the piece of ferromagnetic material consisting of a stamping sheet (1). 4) Dispositif selon la revendication 3, caractérisé en ce qu'il comporte un asservissement en temps réel de la vitesse du poinçon (9).4) Device according to claim 3, characterized in that it comprises a real-time control of the speed of the punch (9). 5) Dispositif selon l'une des revendications 3 et 4 caractérisé en ce qu'il comporte un asservissement en temps réel de la pression exercée par les serre-flancs (8) sur la tôle (1).5) Device according to one of claims 3 and 4 characterized in that it comprises a real-time control of the pressure exerted by the clamps (8) on the sheet (1). 6) Dispositif selon l'une quelconque des revendications précédentes caractérisé en ce que la bobine (4) est de forme allongée, sa longueur étant disposée parallèlement à l'axe de déplacement de la pièce en matériau ferromagnétique (1, 15). 6) Device according to any one of the preceding claims, characterized in that the coil (4) is of elongated shape, its length being arranged parallel to the axis of movement of the part made of ferromagnetic material (1, 15).
FR9014413A 1990-11-15 1990-11-15 DEVICE FOR MEASURING THE MOVEMENT OF AN OBJECT. Expired - Fee Related FR2669418B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR9014413A FR2669418B1 (en) 1990-11-15 1990-11-15 DEVICE FOR MEASURING THE MOVEMENT OF AN OBJECT.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR9014413A FR2669418B1 (en) 1990-11-15 1990-11-15 DEVICE FOR MEASURING THE MOVEMENT OF AN OBJECT.

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FR2669418A1 true FR2669418A1 (en) 1992-05-22
FR2669418B1 FR2669418B1 (en) 1994-05-06

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011038716A1 (en) * 2009-09-30 2011-04-07 Micro-Epsilon Messtechnik Gmbh & Co. Kg Device and method for detecting the motion of a thin body

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3513408A (en) * 1968-08-01 1970-05-19 Tri Metrics Displacement transducer oscillator with movable tapered magnetic core
FR2249530A7 (en) * 1973-10-30 1975-05-23 Raciborska Fabryka Kotlow Rafa
US3891918A (en) * 1971-03-23 1975-06-24 James F Ellis Linear displacement transducer utilizing an oscillator whose average period varies as a linear function of the displacement
US4357816A (en) * 1980-08-21 1982-11-09 Antonov Evgeny A Method of producing hollow articles by deep drawing and press for effecting same
FR2538100A1 (en) * 1982-12-16 1984-06-22 Renault Inductive displacement sensor
JPS6033831A (en) * 1983-07-31 1985-02-21 Matsushita Electric Works Ltd Drawing method
EP0351609A2 (en) * 1988-07-22 1990-01-24 ZELTRON - Istituto Zanussi per la Ricerca S.p.A. A position transducer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3513408A (en) * 1968-08-01 1970-05-19 Tri Metrics Displacement transducer oscillator with movable tapered magnetic core
US3891918A (en) * 1971-03-23 1975-06-24 James F Ellis Linear displacement transducer utilizing an oscillator whose average period varies as a linear function of the displacement
FR2249530A7 (en) * 1973-10-30 1975-05-23 Raciborska Fabryka Kotlow Rafa
US4357816A (en) * 1980-08-21 1982-11-09 Antonov Evgeny A Method of producing hollow articles by deep drawing and press for effecting same
FR2538100A1 (en) * 1982-12-16 1984-06-22 Renault Inductive displacement sensor
JPS6033831A (en) * 1983-07-31 1985-02-21 Matsushita Electric Works Ltd Drawing method
EP0351609A2 (en) * 1988-07-22 1990-01-24 ZELTRON - Istituto Zanussi per la Ricerca S.p.A. A position transducer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 9, no. 158 (M-393)[1881], 3 juillet 1985; & JP-A-60 33 831 (MATSUSHITA DENKO K.K.) 21-02-1985 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011038716A1 (en) * 2009-09-30 2011-04-07 Micro-Epsilon Messtechnik Gmbh & Co. Kg Device and method for detecting the motion of a thin body

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