FR2554228A1 - APPROACH DETECTOR - Google Patents

Abstract

THIS APPROACH DETECTOR 1 INCLUDES A BOX 2 AND A DETECTION FIELD 8 OUTSIDE THE BOX 2. ACCORDING TO THE INVENTION, THE DETECTION FIELD 8 IS ARRANGED LATERAL ON THE BOX 2 AND IS ORIENTED PERPENDICULARLY TO THE LONGITUDINAL DIRECTION OF THE CASE 2. ACCORDING TO ANOTHER CHARACTERISTIC, CASE 2 IS CYLINDRICAL CIRCULAR AND HAS, AT AN AXIAL END, THE SHAPE OF A PORTION OF CYLINDER 6 APLATIA AND DETECTION FIELD 8 IS ON THE FLAT BOUNDARY SURFACE 7 OF THE PORTION OF CYLINDER 6. THIS APPROACH DETECTOR MAY BE ELECTROMAGNETIC, OPTICAL OR ACOUSTIC. IT CAN BE ADVANTAGEOUSLY USED AS A POSITION INDICATOR FOR THE CONTROL OF A PRESSURIZED FLUID ACTUATED CYLINDER.

Description

255422U

APPROACH DETECTOR

  The present invention relates to an approach detector comprising a housing and a detection field

outside the case.

  Approach detectors are used to detec- tor contactlessly the positions of parts displaced relative to one another. There are, for example, electromagnetic sensors formed by inductive or capacitive approach detectors, which react with metallic objects in the vicinity of the field of view.

  detection. These approach detectors may have a housing

  quadrangular and they are further mounted in accordance with an ISO standard in a cylindrical housing

  circular with an external metric thread. The dimensions

  The most used nets are M8, M12 and M18.

  In known approach detectors, the detection field

  Sensitive sensing of the sensor is always on one end face of the housing and the measuring field of the approach detector is in the extension of the longitudinal direction of the housing. This arrangement requires a mounting position of the approach detector in which the longitudinal direction of the housing extends at right angles to / relative to the path of movement of the piece.

  to detect. This requires an important place. -

  The object of the present invention is to overcome this drawback and to achieve an approach detector whose installation requires a much smaller footprint. The approach detector according to the invention must, in addition, be subjected minimally to the risk

of operating incidents.

  This object is achieved according to the invention in that

  the detection field is arranged laterally on the housing

  tier and is oriented perpendicular to the direction

longitudinal housing.

  This configuration makes it possible to orient the detection

  approach so that the longitudinal direction

  its housing is parallel to the path of movement of the part to be detected. In this way, it is possible in many applications to reduce the mounting width in a perpendicular direction

  to this trajectory of displacement.

  According to a preferred embodiment of the invention, the casing is circular cylindrical and has an axial end in the form of a flattened cylinder portion and the detection field is on the surface.

  plane delimitation of the cylinder portion.

  In this arrangement, the detection field is particularly well protected and there is almost no risk that the body has to be detected and

  moving on a trajectory does not inadvertently

  the detection field. The risk of deterioration

  is therefore considerably reduced compared to the

  known end of the detection field.

  It is, moreover, advantageous to provide the housing with an external thread, a metric thread according to the aforementioned ISO standard that can be provided in particular. This arrangement of the thread makes it possible to use the detector

  approach of the invention wherever the normal sensors

  meadings commonly used so far were

generally mounted.

  Thus, a great deal of flexibility is

lisation.

  Another concept of the invention relates to the position of the connection of the approach detector. Outlets for power supply and signal transmission on the face should be removed

  at the end of the case, which is located opposite the end

  flattened mity bearing the field of detection. Fittings

  out of the housing in the longitudinal direction, that is

  to say that they extend approximately in parallel

  to the trajectory of the body to be detected. This posi-

  connection is desirable in many applications.

  practical cations. It can not be achieved in the

  known approach detectors, whose longitudinal direction

  dinal of the housing is oriented perpendicular to the path of movement of the body to be detected, that folding the fitting to 90. But there is always the risk, during such an operation, of damaging the lines and the present invention completely avoids this disadvantage.

  The function of the approach detector according to

  vention may be based on detection principles

  electromagnetic. In particular, one can consider a

  me as an inductive approach detector

or capacitive.

  Such approach detectors are characterized

  by a relatively simple and robust construction.

  They react generally to metals, which opens up many possibilities of use. However, a magnetosensitive element that reacts with ferromagnetic materials or external magnetic

  instead, to optical or acoustic detection principles.

  The approach detector according to the invention can therefore be adapted, therefore, universally to the physical characteristics of a mass moved along a path and to be detected, and can, therefore, be used

  for extremely multiple applications.

  The approach detector according to the invention finds a preferred application as a position indicator for the control of a fluid actuated cylinder under

  pressure. This application provides the particular advantage

  to bind that the approach detector can be oriented so that the longitudinal direction of its housing is parallel to the direction of linear displacement of the jack,

  while occupying only a very small place in a

  perpendicular to this direction of travel.

  A cylinder equipped with an approach sensor con-

  form to the invention has, therefore, an ex-

very compact.

  In any case, the invention will be well understood and other features and advantages thereof

  will be highlighted using the description that

  follows with reference to the attached schematic drawing showing, by way of non-limiting example, a form of embodiment:

  - Figure 1 is a perspective view of a

  approach sensor according to the invention; FIG. 2 diagrammatically represents an example of use of the detector according to the invention compared to

the state of the art.

  Referring first to Figure 1,

  recognizes an approach detector (1) having a bolt-

  tier (2) of substantially circular cylindrical shape.

  The length of the housing (2) corresponds to a multiple of its diameter. The cylindrical casing of the casing (2) is provided along its entire length with an external thread (3), a metric thread of standardized size M8, M12 or M18 being preferably used. The external thread (3) allows the approach detector (1) to be screwed into a

  threaded hole of a housing, a support or other.

  To each approach detector (1) are associated two mounting nuts or locknuts (4) which are screwed on the outer thread (3). These also serve,

  in a way that is easy to imagine, to set the

  approach detector (1). For example, a hole may be provided for this purpose in a support plate, hole in which the approach detector (1) is depressed in the manner of an ankle, with a single nut (4) screwed on. The second nut (4) is then screwed onto the approach sensor (1) from its free end, so that the support plate comes between the two nuts. By loosening the nuts (4), it is possible to adjust both the axial length and the angular position

  of the approach detector (1), before locking it in ser-

nuts (4).

  A cable (5) is used to connect the approach detector (1). It comes out of one of the end faces of the cylinder housing (2) coaxially with it. The cable (5) encloses lines which serve to supply energy and / or conduct the electrical signals of the approach detector (1). The axial end of the housing (2) turned on the side

  opposite to the cable connection a, in the exemplary embodiment

  shown, the shape of a flattened portion of cylinder (6). The cylinder portion (6) has a planar boundary surface (7) which extends parallel to

  a plane containing the axis of the cylinder.

  The solid body of the cylinder segment (6) occu-

  eg a volume greater than half of the cylindrical body

circular (2).

  The external thread (3) extends along the length of the cylinder segment (6), so that the nuts (4) can be screwed onto the area of the flattened body. The axial length of the cylinder segment (6)

  is reduced; it corresponds to a little more than the size

  detection field (8), what constitutes the element

  sensory approach sensor (1).

  In the known approach detectors (1), the detection field (8) is arranged on the end face (9) of the cylindrical gearbox (2) which is located opposite the cable connection. The sensitivity zone of such a detection field is in the extension of the longitudinal direction of the housing which implies a

  mounting position of the perpendicular approach

  to the path of movement of the body to be detected.

  The present invention is moving away from this form of

  struction. It plans to orient the detection field

  (8) with its sensitive area perpendicular to the di-

  longitudinal rection of the housing (2) and to arrange the

  detector field (8) laterally on the housing (2).

  In the preferred embodiment shown in FIG. 1, the detector field (8) is, for this purpose,

  the plane delimiting face (7) of the portion of cy-

  lindre (6) On the basis of this arrangement, the approach detector according to the invention reacts, among others, masses moved along a path that extends parallel to the longitudinal direction of the housing (2).

  The detector field (8) is protected, in a manner indicative of

  against direct contact by such masses,

  since the latter would come at most

  tact with the end face (9) of the cylinder which delimits

  the cylinder portion (6) in the axial direction.

  There is therefore no risk of deterioration

  detector field (8). Particularly complex montages

  pacts and space-saving can, in addition, be realized

  because of the "aiming direction" of the detector of appro-

  che (1) perpendicular to the longitudinal direction of the housing. FIG. 1 shows the object of the invention in a preferred construction form as a detector

  inductive proximity. The housing (2) encloses an oscilla-

  which produces an electromagnetic field. It is

  radiated by the detection field (8) more or less

  pendicular to its surface. If a metallic body reaches the vicinity of the detection field (8), the

  electromagnetic field will be attenuated by the current pa-

  rasites induced in the metal. This depreciation will be detected by an increase in the power absorbed

  by the oscillator and the proximity detector (1)

  a control signal to an operating switch.

  In a quite similar way, the detector according to the invention can however also be designed

  as a capacitive approach detector.

  It is also possible to have

  right of the detector field (8) a detector installation-

  emitter for optical or acoustic radiation and to detect a mass moving on a trajectory

  by reflection or absorption of radiation.

  The transmitter can be formed by a source of

  visible light or infrared radiation, for example

  a laser, and a semiconductor detector can serve as a radiation receiver. It is also possible to install at the location of the detector field an ultrasonic transmitter and receiver. It is common to all these forms of construction that a radiation serving to highlight the mass displaced on a trajectory

  is sent perpendicular to the longitudinal direction

  housing (2) and substantially perpendicular to the surface of a detection field (8) which is

  its side oriented parallel to a longitudinal median plane

  dinal of the housing (2). The sensitivity zone of the approach detector (1) extends laterally

of the housing (2).

  Referring now to Figure 2, this

  This schematically illustrates an example of pre-

  of the approach detector (1) according to the invention. The approach detector (1) serves as a position indicator for actuating a cylinder (11) actuated by pressurized fluid. A tube of

  cylinder (12) closed at both ends by two sections

cylinder louvers (13).

  A piston (4), connected to a piston rod (15),

  and actuated by fluid under pressure moves to the in-

  inside the cylinder (12). The piston rod (15) comes out

  the cylinder (11) by one of the cylinder covers (13).

  It serves to transmit the driving force to an element coupled to this piston rod (15) and not shown more precisely. On the piston rod (15) is mounted an indicator ring (16), whose position is

  detected using the approach detector according to the invention.

  tion. Detection of the position of the indicator ring

  this (16) can be used to limit the axial displacement of the piston (14) or the piston rod (15) and to reverse the pressurized fluid supply of the cylinder (11)

  when the corresponding end position is reached.

  The proximity sensor (1) according to the invention has a mounting position in which its housing has

  a longitudinal direction parallel to the rod of pistons

  your (15). This mounting position is made possible by the "sighting direction" of the detection field (8) perpendicular to the longitudinal direction of the housing (2). It is recognized that this arrangement of the proximity sensor (1) in the radial direction relative to the rod

  piston (15) requires very little space.

  A proximity detector (17) with a de-

  located on the end side, as is well known

  in the state of the art, must, on the other hand, be

  perpendicular to the longitudinal direction of the piston rod (15), that is to say to the direction of movement of the cylinder (11), which requires a space

  much bigger. A jack (11), equipped with a sensor

  approacheur (1) according to the invention, therefore has a substantially more compact construction. Another advantage of the present invention lies in the departure of the cable (5) parallel to the direction of movement of the jack (11). Such a departure of the cable is desired in many cases of use and could not until now, taking into account the state of the art, be obtained by strongly bending the cable (5) to 90, which presented risks of deterioration. The detector field (8) is in the construction according to the invention remarkably protected against a contact

  with the mass to be detected and the risks of

  deterioration and operational incidents are consid-

  significantly less than the provision on

  one of the end faces of the cylinder exposed above.

  Finally, it should also be noted that the approach detector (1) according to the invention is not

  nothing less than the approach detector (17)

  naked, regarding its installation flexibility. he

  it is quite possible to use the detector of appro-

  che (1) according to the invention also in a mounting position perpendicular to the longitudinal direction of the piston rod (15); the approach detector would then rise, in Figure 2, perpendicularly

at the drawing level.

Claims (8)

  1 - Approach detector comprising a housing   and a detector field provided on the outside of the box   characterized in that the detection field (8) is arranged laterally on the housing (2) and is oriented   perpendicular to the longitudinal direction of the wood tier (2).   2 - approach detector according to claim 1, characterized in that the housing (2) is circular cylindrical and has, at one axial end, the shape of a flattened portion of the cylinder (6), and in that the field detection (8) is on the bounding surface   plane (7) of the cylinder portion (6).   3 - Approach detector according to one of the   1 or 2, characterized in that the housing (2) carries an external thread (3).   4 - Approach detector according to one of the   2 or 3, characterized in that at least one coupling   (5) leaves the end face of the housing (2) opposite the former flattened tremity (9) of it.   - Electromagnetic approach sensor (1)   and preferably inductive according to any one of the Claims 1 to 4   6 - Optical approach detector (1) according to one   any of claims 1 to 4.   7 - Acoustic approach detector (1) according to   any of claims 1 to 4.   8 - Use of an approach detector (1)   according to any one of claims 1 to 7 as   - position indicator for controlling a cylinder (11) ac- fluidized under pressure.