FR2459455A1 - DEVICE INDICATING INDICATOR OF COURSE AND / OR ANGLE - Google Patents

Abstract

A. COURSE AND ANGLE INDICATOR. B. THIS INDICATOR, WHICH INCLUDES AN INDUCTION WINDING SUCH AS A COIL 72 MOUNTED ON AN IRON CORE 70 WITH TWO BRANCHES 71, 74 CROSSED BY A MAGNETIC FLOW 77 AND PRESENTING AN AIR SLIT ALSO CROSSED BY THIS MAGNETIC FLOW 77, IS CHARACTERIZED BY A BODY IN ELECTRICALLY CONDUCTIVE MATERIAL CAPABLE OF DAMPING THE INDUCTIVITY L OF THE COIL 72, CONSTITUTED FOR EXAMPLE BY A SEMI-CYLINDRICAL DAMPERING SHEET 73 THAT CAN ROTATE AND ENGAGE IN THE AIR SLOT COMPRISED BETWEEN THE BRANCHES 71, 74 BODY CONNECTED TO THE MOVABLE PART WHOSE MOVEMENT IS TO BE DETECTED. C. THE INVENTION APPLIES MAINLY TO INDICATOR DEVICES DETECTING THE POSITIONS OF A MOVING PART, FOR EXAMPLE OF A PART MOVING DURING THE DOSING OF FUEL OF AN INTERNAL COMBUSTION ENGINE.

Description

The invention relates to an induction device indicating a path

  and / or angle for detecting the position of a construction part, in particular a part which moves during the fuel metering of an internal combustion engine, comprising an induction winding mounted on an iron core traversed by a magnetic field, and which includes an air gap also traversed, at least in part, by

the magnetic field.

  Induction indicators of this type are already known, in which, on at least one branch of the iron core is disposed a short circuit ring connected to a moving part of construction, this ring being made of magnetically non-conductive material but with electrical conductivity. high. The induction coil placed on the iron core is traversed by an alternating current and produces a field

  Alternate magnetic that passes through the nucleus. The ring of

  circuit constitutes, for the core branch on which it

  is guided without contact in the longitudinal direction, a winding

  short circuit through which the alternating magnetic field

  native can not penetrate. As a result, the total magnetic flux is limited, with a good approximation, to a value proportional to the position of the short-circuit ring, so that the inductance of the coil can be modified according to the position given to this ring, and proportionately

to his movement on the branch.

  The short circuit ring used in this known device is relatively expensive. In addition, an important construction expense is necessary for the

  non-contact guidance of the ring on the core branch.

  The object of the invention is to provide a device

  inductive indicator which requires only a manufacturing expense

  considerably smaller and constitutionally

simpler.

  For this purpose, the indicator device of the invention

  tion is characterized in that it comprises a damper member of good electrically conductive material, in particular of copper, which is coupled to the movable component, and

is engaged in the air slot.

  The invention will be better understood using the

  description below and accompanying drawings showing

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  schematically various embodiments of the invention, drawings in which:

  - Figure 1 is an overview of an indica-

  in accordance with the invention with two iron cores and two

dampers of inductivity;

  FIG. 2 is a similar view of another example;

  ple of this indicator, having a different arrangement of the two cores and four damping disks; - Figure 3 shows another embodiment with iron core, rotor armature and short-circuit caliper;

  FIG. 4 is a view of an arrangement corresponding to

  laying a doubling of the device of Figure 3; - Figure 5 shows a variant of the short-circuit stirrup; FIG. 6 is a view of another embodiment of the indicator with an iron core with a coil whose inductivity is modified by means of a damping plate; FIG. 7 shows two positions of rotation of this damping head; - Figure 8 shows a doubling of the device of Figure 6; Fig. 9 is a view of an iron core indicator and movable short circuit frame; - Figure 10 shows a variant of the frame of

short circuit.

  The example shown in Figure 1 comprises two iron cores 16 and 17 with three branches, which are arranged diametrically opposite to the shaft 15 so that in common planes perpendicular to the shaft 15, the outer branches 18 and 19 of the two respective cores 16 and 17, the median branches 20 and 21, and the lower outer branches 22 and 23,

  face each other at the same distance from the shaft 15.

  On the middle branch 20 of the right-hand core 16, an induction winding 24 is arranged, while on the

  middle branch 21 is arranged a second inductive winding

  25. In each interval between the median branches 20 and 21 and the outer branches 18, 19 and

  22, 23, penetrate two damping disks identically shaped

  that 26 and 27. These disks are attached to the shaft 15 being

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  axially spaced from one another and united in a conductive

  trice, for example by means of a sleeve B. They present a

  edge contour 28 which extends symmetrically in a plane pas-

  by the axis A of the shaft 15 and not shown in the drawing.

  The radial distance r from the edge 28 increases, from a minimum value r0 for ci = o, to a rotation angle of 1800, linearly up to a maximum rMax = r0 + c. 1800 and decreases

  then linearly when the shaft 15 continues to rotate.

  In the angular position cd = 1800 represented

  in FIG. 1, the two damping disks 26 and 27 penetrate

  trent deeper into the right-hand core 16 and the

  less deeply in the left-hand core 17, whose winding

  In this position, the induction electrode 25 is accordingly

  angular the greatest inductivity, while the inductive

  the right winding 24 is at its minimum.

  In the angle indicator of Figure 2, as-

  in that of Figure 1, provision is made for a different

  As a result, on the common shaft 15, four damping disks 31 to 34 are arranged in pairs. These four disks are congruent with each other, but they are mounted in pairs on the shaft 15, being offset from one another so that, for a given rotation of the shaft 15 of an angle, the two upper damping disks 31 and 32 penetrate into the upper core 16, from the maximum depth

  represented in the drawing, progressively less and less

  demented in the core, while the two lower damping disks 33 and 34, from a zero depth shown, gradually penetrate deeper and deeper into the core 17. The inductivity of the windings 24 and 25 consequently decreases in the one of the coils while she believes in the other. Whereas, in the embodiment according to FIG. 1, the two E-shaped iron cores 16 and 17 are diametrically opposed, they are placed in FIG. 2 on one of the sides of the shaft 15, in a common plane passing through the axis of the shaft, which allows, on a 360 degree rotation zone, to detect the angular position and the speed of rotation.

  rotation of the shaft 15 which occur in each case.

  With the embodiment shown in FIG. 3, it is possible to detect two translation displacements perpendicular to each other, as well as two rotational displacements. This path and angle indicator has a U-shaped iron core 36 with superimposed lamellae. Between the branches 37 and 38 of this core, there is provided an iron-rotor frame 39, also in strips in the longitudinal direction, arranged in such a way that between the end faces of the rotor and each end section of the branches 37 and 38, there remain respective air slots of the same size 40 and 41.

  On the rotor 39 is mounted a winding inductor.

  42 with many turns, which can be fed with a constant alternating current to produce a magnetization

  effective in the core 36 and in the rotor 39. The electromagnetic flow

  the magnetic coil passes through the winding of the rotor 42 with an intensi-

  which depends on the depth with which the two ends of the branches 44 and 45 of an oDurt-circuit yoke 46 penetrate

in the air slots 40 and 41.

  The short-circuit bracket 46 is constituted by a curved U-shaped copper plate and is coupled

  with a piece of construction, not shown, whose displacements

  Cements are transmitted to this bracket 46 and communicate two translational displacements V1 and V2 perpendicular to each other and a rotational movement or pivot V3. The magnitude of the magnetic flux passing through the rotor winding 42 depends on the depth of penetration of the legs 44 and 45 of the yoke 46. Accordingly, the inductivity of the winding 42 is a measure of the engagement depth. , that is to say for the

  race imposed on branches 44 and 45.

  In the embodiment of Figure 3, there is provided on the inner face of the U-shaped iron core 36, a copper plate 47 in the form of 4 friar which opposes a deflection

  side of the field lines in relation to the short bracket

circuit 46.

  As a variant of the example shown, it is possible

  to connect the armature 39 on one side to the two-side urodes

  37 or 38 of the iron core 36, so that a result with a single air gap. Such a

  Provides the advantage that the rotor armature 39 carries

  the winding 42 can be fixed more easily, for example by means of the stationary short-circuit head 47,

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  if it is extended until it is applied against the armature

39 of the rotor.

  The exemplary embodiment according to FIG.

  kills a doubling of the indicator of Figure 3 in a different arrangement. In this case, a second iron core 50, with armature 51 and coil 52, is arranged quite symmetrically with respect to an axis B indicated by a line in dot-dots in the figure. These elements correspond to those of FIG. 3. They are represented in FIG.

  left of the axis of symmetry B and are provided with the same numbers

  referenced as in Figure 3.

  Between the two iron cores 36 and 50, there is provided a common short-circuit yoke 54 in the form of a double T, which consists of a copper plate and has a vertical longitudinal branch 55 extending parallel to the B axis and to distance from it. From this vertical branch extend, at the upper end, two horizontal arms 56 and 57, and at the lower end, two horizontal arms 58 and 59. The two arms 57 and 59 penetrate deeply - in the position represented by the short-circuit stirrup 54 -, between the two air slots of the left-hand core 36, covering the

  total frontal area of the frame 39 of the left rotor.

  On the other hand, the right arms 56 and 58 remain, in the position

  shown, outside the corresponding air slots

iron core 50.

  The short-circuit bracket shown may execute, with respect to the axis B, a translational movement indicated by an arrow V1 or a rotational movement V3 about the axis B; in both cases, the inductivity of one of the two windings, for example the winding 42, is increased and, in

  At the same time, the inductivity of the second winding 52 is decreased.

  The shape of the characteristic curve can then be influenced by the special shape of the periphery curve of the surface F. FIG. 5 shows an alternative embodiment for a short-circuit stirrup which can find its use instead.

  of the stirrup 54 shown in Figure 4.

  The short-circuit calliper according to FIG.

  consisting of a curved copper sheet strip.

  It comprises a vertical median branch 60, from which two upper arms 62 and 63 are bent at right angles to opposite sides and which have a width equal to only half of that of the middle branch 60. At the lower arm 59 of the Figure 4 corresponds, in the variant of Figure 5, a tongue 65, which is bent from the middle branch 60 in a direction opposite to that of the second lower tongue 64. The two pairs of tabs on the right form, in common with the middle branch 60, one of two short-circuit callipers. One of them, during translational displacement

  indicated by the arrow V2, increases the inductivity of the winding

  52 and decreases that of the left winding 42, in the direction in which the short-circuit caliper

is moved.

  In the exemplary embodiment according to FIG. 6, there is provided a two-branched U-shaped iron core 70, in which the branch designated 71 carries a coil 72 whose inductivity can be modified using of a head

  semi-cylindrical damping device 73, which surrounds the other

  74 of the nucleus about half of its circumference. The damping plate 73 forms part of a copper bush 75 which, to form the semicylindrical head 73, is cut about half of its axial length, and which is bounded by a transverse cutting surface 76. its axis of rotation C. When the bushing 75 is rotated by an angle of rotation t around the axis C, the damping head 73 can assume the position shown in FIG. 7 corresponding to q.9 O ; in this position, the plate 73 does not interrupt the field lines, which extend from the branch 74 to the branch 73 or vice versa, of the magnetic field produced in the core 70, so that the inductivity L of the coil 72 presents a

  maximum value. This value decreases to a minimum value

  when rotating the head 73 in the position

  7. After a rotation of If = 1800, the damping head 73 is actually placed completely between the two branches 74 and 71 and protects the

  coil 72 against the magnetic flux 77.

  The arrangement shown in front view in FIG. 8 is practically a doubling of the example of FIG. 6. In fact, on each of the outer branches 81 and 82, an E-shaped iron core 80 has been disposed one coil 83 or 84 respectively; it is then expected, known in

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  the example of FIG. 6, a semi-cylindrical damping head

  73, which surrounds the median branch 85 of the core 80 on half of its periphery, and which, depending on its angle of rotation, closes the median branch 85 more or less with respect to the outer branches 81 and 82 In the position shown in FIG. 8 of the damping spring 73, the inductivity L1 of the coil 83 is significantly lower than the inductive L2 of the coil 84, in which the magnetic field produced in the core 80 can be fully exerted. In the following example the Figure 9, the nucleus of

  iron 90 carries on its median branch 91 a winding inductive

  92 traversed by an alternating current which produces a closed flow C through the two core branches 93 '94 and the air slot 95 remaining free between themo In the air slot 95 is engaged a frame 96 stamped in a plate of This frame has a rectangular shape and can be moved parallel to its longitudinal sides 97, 98, towards the path to be mored between the two branches 93 and 94, depending on the position occupies a building part to be monitored, for example the adjustment rod of an injection pump. Through the electromagnetic alternating field are produced in the frame 96 of the short-circuit currents, which restrict the effective magnetic field outwardly in the air slot 95 especially as the frame is engaged more deeply between the branches 93 and 94 according to the

course to measure s.

  Figure 10 shows a short-term

  improved circuit that captures a larger portion of the scattered magnetic flux of the indicator. In particular, this short-circuit frame comprises two transverse branches 101 and 102 curved in the shape of a U which connect the sides to one another

  longitudinal axes 103 and 104 of the frame, by their end portions.

  moth. The short-circuit frame shown in FIG. 10 provides the advantage that it provides, with a reduced mass, a strong modification of the inductivity of the winding 91, that it can be freely moved on the branches 93 and 94, without

  its movement is impeded by a stop, and that, moreover, its manufacture

  cation is possible in the simplest way, by folding

  and curvature of thread or tapes.

Claims (18)

REVENDICATI 0 NS) An induction device indicating a path and / or an angle for detecting the position of a workpiece, in particular a part which moves during the metering of fuel of an internal combustion engine, comprising a induction winding mounted on an iron core traversed by a magnetic field, and which comprises an air gap also traversed at least in part by the magnetic field, indicating device characterized in that it comprises a damping inductivity member (26, 27, 31l34, 46, 64, 60, 73) of electrically conductive material, especially copper, which is coupled to the movable construction part and is engaged in the air slot.   2) Device according to claim 1, characterized   characterized in that the iron core (16, 17, 36, 50) is U-shaped, and the plate of the damping member (26, 27, 31 to 34, 46, 54, 60, 73) is engaged between the branches (18, 20, 22 or 19, 21, 23 or 71, 74) of the U.   Device according to claim 2, characterized   in that the iron core (16, 17) is E-shaped.   4) Device according to any one of the   1 to 3, characterized in that the damping member has a plate-shaped flat portion (44 or 45) which is movable in the air slot (40 or 41) towards the plate plan.   Device according to claim 4, characterized   in that the U-shaped iron core (36) is provided, between the free end portions of its branches (37, 38), with an armature (39) of magnetically conductive material, which   forms the air slot (40) with one of the branches.   Device according to claim 5, characterized   rised in that the armature (39) forms in front of each of the two branches (37, 38) of the iron core (36) one of two air slots (40, 41).   7) Device according to any one of the   1 to 6, characterized in that the middle part of the core (36) which reduces the branches (37, 38) comprises a permanent magnet.   8) Device according to any one of the   5 to 7, characterized in that the induction winding   (42) is disposed on the frame (39).   ) Device according to any one of the   5 to 8, characterized in that the damping member (46) is U-shaped and has two legs (44, 45 or 56- / 58, 57/59, 62 to 65) for engage in   the air slot (40, 41) of the core (36).   ) Device according to any one of the   1 to 9, characterized in that two cores are provided   iron (16, 17) arranged in the same plane.   110) Device according to Claim 10, characterized in that the two cores (16, 17) face each other   by the free end portions of their branches, to   and diametrically opposite positions with respect to an axis of symmetry (A, B) and in particular in symmetrical positions compared to a plan.   12) Device according to claim 11, characterized in that between the end faces of the free end portions of the legs of the core (16, 17) is disposed a rotary shaft (15) carrying at least one damping head (28).   13) Device according to claim 12,   characterized in that the damping head (28) is constituted   killed by a disc, whose edge is at a radial distance from the axis of rotation (A) of the shaft (15) which increases with a increasing center angle.   Device according to Claim 13, characterized in that the radial distance (r), in the region of a central angle or angle of rotation (c) from 0 to 1800, increases, in particular linearly, and decreases linearly in the 180 to 3600 area of the rotation.   ) Device according to any one of the   10 to 14, characterized in that, on a common rotary shaft (15), there are two identical disk-shaped damping plates (28), each of which can be pivotally engaged in a slot between the middle branch (20). or 21) of the two E-shaped cores (16, 27) and an outer branch of these nuclei.   Device according to claim 11, characterized in that the damping plate (56, 57, 58, 59 or 62, 63, 64, 65) is provided so as to be pivotable about the axis of symmetry (B). of the two nuclei (36, 50), but   asymmetrical way with respect to this axis.   Device according to Claim 16, characterized in that two damping plates (56, 57, 58, 59 or 62, 63, 64, 65) axially spaced apart are provided   pivotable around the axis of symmetry (B).   18) Device according to claim 17, characterized in that the damping plates (56, 57, 58, 59 or 62, 63, 64, 65) are arranged in pairs each in one of two axially spaced planes, s extending transversely   to the axis of symmetry (B) and are connected to each other preferably   by a cross member (55) parallel to the axis (B).   19) Device according to claim 18, characterized in that the damping plates (62, 63 or 64, 65) located in the same plane, are bent towards sides   opposed from the common cross member (60).   ) Device according to claim 10, characterized in that the two cores (16, 17) are arranged, by the end faces of their ends of branches, in front of a rotary shaft (15) carrying at least two damping t8les (31 to 34) disc-shaped, the two cores   being offset from each other at axial spacing with respect to the shaft.   210) Apparatus according to claim 20, characterized in that the damping plates (31 to 34) have identical upper faces, in particular limited by an edge, whose distance to the axis of the shaft (15) increases in the direction of rotation of the tree for one of the t8les and decreases for the other.   220) Device according to claim 21, characterized in that the two cores (16, 17) are E-shaped and each carry on their central branch (20, 21) an induction winding (24, 25), and at each of the cores, two damping heads (31, 32 and 33, 34) are assigned   form of spiral-limited discs that can be   pivoted between the two outer branches and the middle branch of their respective core, the plates (33, 34) assigned to the second core (17) being arranged on the opposite side of the shaft (15) with respect to the two heads ( 31, 32) assigned to the first core (16).   230) Device according to Claim 22, 1 2459455   characterized in that the radial distance (r) of the edge (28) of the damping plate, for an angle of rotation extending over 360, varies, preferably linearly, between a minimum value and a maximum value, depending on the angle of rotation.   24) Device according to one or the other of the   2 and 3, characterized in that the damping member   (72) consists of a semi-cylindrical envelope surface   at least approximately which remotely surrounds one of the branches (74) of the core (70) about half of its circumference, the cylinder axis of this envelope forming its axis of rotation and coinciding in particular with the longitudinal axis of the branch passing through the center of gravity of its frontal surface.   25) Apparatus according to claim 24, wherein   having an E-shaped core having a middle branch and two outer branches, characterized in that on each of the two outer branches (81, 82) is disposed one of two induction coils (83, 84), the 'amortization   (73) being arranged to be rotatable about the longitudinal axis   tudinal of the middle branch of the nucleus.   26) Device according to claim 2, characterized in that the damping member is constituted   in the form of a frame (96) including a rectangular frame.   27) Device according to claim 26, characterized in that the frame (96) is guided so as to slide parallel to a ceté, including one to its longitudinal sides (97, 9E8).   28) Device according to claim 27, characterized in that the longitudinal sides (103, 104) of the frame are connected at each end by one of two sleepers   curved U-shaped (101, 102).   29) Device according to any one of the   26 to 28, characterized in that the frame (100) is   made of wire or strips of curved t8les.