SENSOR DEVICE FOR GEOMETRICALLY TESTING PARTS
A feeler device for geometrically controlling parts, capable of determining the position of a feeler member when it comes into contact with a part to be controlled. The feeler device includes a motorized contact rod movable in translation inside a housing and a microcontroller for controlling the movement of the rod. The contact rod is driven in translation by friction with an element linked to the rotary shaft of a motor, and the contact rod cooperates with a magnetic sensor in order to detect the position of same.
- 1-15. -15. (canceled)
- 16. A sensor device for geometric testing of parts, able to determine a position of a sensor body when the sensor body enters into contact with a part to be tested, the sensor device comprising:
a case; an engine; a contact rod, motorised between an extended position and a retracted position relative to an inside of the case; a microcontroller for controlling the movement of the rod; a magnetic sensor, which cooperates with the contact rod to detect a position thereof; and a counter-brace or restraining part, which forms a friction-contact counter-brace of the contact rod with a rotating axis of the engine, said a counter-brace or restraining part being fixed on said case.
- View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
The invention relates to the field of detecting the position of a sensor body when it enters into contact with a part to be tested.
In industry, it is usual to test the quality of parts and, in particular, test their geometry, either alongside the production chain (in other words, during production), or at the end of production. It is therefore necessary to provide a specific test station, wherein the part to be tested is brought to be tested there by an operator. For a long time, a gauge has been used for this purpose; this test operation requires a prior calibration for a given standard value and the operator checks if the standard value is adhered to at the level of the part to be tested. Even if all parts of a series are not thus tested manually, such a test takes time, which is not compatible with sustained production paces. Accelerating paces in production chains makes such a test problematic, even inoperative.
In addition, such an operation is costly in time, in material; furthermore, problems with reliability can occur. That is why a quicker processing of parts to be tested has been searched for, which, moreover, is reliable and cheap.
The patent application FR 2 997 490 partially responds to this problem, by proposing a semi-automatic geometric test device, with magnetic encoding. In this device, the sensor body is supported by a rod assembled moving forward inside a support case, opposite the fixed magnetic sensor means supported by the case, and sensitive to magnetic encoding magnetised markers that the rod supports for detecting the position of this rod. Contrary to the prior art, this device constitutes an improvement, in that it enables a reliable, solid measurement to be taken, with cheap equipment. In this system, the case integrates all the necessary components, on the one hand, for detecting a contact of sensor means, and on the other hand, for utilising this detection for measuring the movement of the sensor means, such that this device is autonomous and enables automatic measurements to be taken at a quite sustained pace.
However, improvements have proved to be necessary, in particular at the level of reliability regarding adjustment, movement speed of the sensor rod, or contact of the rod with the part to be tested; the precision of the measurement is another parameter which requires an improvement, as demanded by manufacturers.
The invention aims to remedy the disadvantages of the state of the art, in particular, concerning the reliability of the measurement, the speed thereof, as well as the protection of the sensor rod. By rod or contact read, this means the extended element, of which the end enters into contact with the part to be measured.
The invention relates to a sensor device for the geometric testing of parts, able to determine the position of a sensor body when it enters into contact with a part to be tested, comprising a motorised contact rod, moving forward inside a case, a microcontroller controlling the movement of the rod.
According to a first aspect of the invention, the rod cooperates with a magnetic sensor for detecting the position thereof.
According to a first embodiment of the invention, said contact rod is driven forward by direct or indirection friction with the rotating axis of an engine.
These characteristics improve the reliability of the measurement, the speed thereof, as well as the protection of the sensor rod.
Usefully, the device according to the invention comprises a counter-brace or restraining part for the friction-contact counter-brace of the sensor rod with the rotating axis of the engine, said part being fixed on said case.
According to an embodiment of the invention, the counter-brace or restraining part comprises a roller.
According to another embodiment of the invention, the counter-brace or restraining part comprises a gasket for guiding said rod, which extends partially inside the case and has a notch there able to constitute two support edges.
According to another aspect of the invention, the sensor device comprises at least one electronic board and software for managing the position of said rod, cooperating with the microcontroller.
More specifically, the sensor device comprises a first and a second electronic board, the first enables the acquisition of the measurement of the position of the rod, the second board enables the processing of the measurement of the position, as well as the acquisition and the processing of the force exerted on the contact rod. Here, it is useful to mechanically disengage the functions managed by the first and by the second boards, as the reliability of the adjustment in improved, in particular, the adjustment of point 0.
According to another characteristic, the device comprises a means for adjusting the pressure exerted by the contact rod on the part to be tested, configurable by the controlling means of said engine. Thus, managing the force exerted by the rod is improved.
Usefully, the device according to the invention comprises a magnetic strip positioned on said rod, to detect the position thereof by cooperating with the magnetic acquisition means. The action of positioning a magnetic strip directly on the rod constitutes a simplification of the system which increases both the reliability and the precision of the measurement.
According to a useful variant of the invention, the engine used is of a linear type. Advantageously, the engine can be arranged in the extension of the rod and can comprise a pile (or alignment) of mobile magnets of alternatively inversed polarities with the rod, and a stator controlled by one of said electronic boards. This variant enables the volume of the device to be reduced, and also to increase the lifespan thereof, comparatively to using a rotary engine, for example.
Specifically and preferably, in a variant comprising a linear engine, said stator is fixed in said case and comprises a solenoid, of which the propulsions act on the pile of magnets to ensure the movement of said rod.
Conforming with another variant of the invention, said pile of magnets cooperates with a position detector and said stator in order to ensure both the movement of the rod and the detection of the position of the rod.
In addition, the device according to the invention can comprise sealing and protective means cooperating with at least one part of said case and/or said rod.
Moreover, the device according to the invention can comprise a display unit for reading at least one functioning parameter and/or for controlling said functioning. The display unit advantageously enables a reading of the information and an in situ and immediate configuration, hence an improved reactivity.
Other characteristics and advantages of the invention will emerge upon reading the description which follows, in reference to the appended figures, which illustrate:
To be clearer, identical or similar elements are referenced by identical reference signs in all the figures.
Means for detecting the position of the rod 1 are provided on the second electronic board 8. The rod thus moves between an initial or retracted position, according to which only the head 2 goes beyond the outside of the case 3, and a maximum outlet position, wherein the head 2 is located farther away from the case 3. The part to be tested is located between these two positions.
The principle of detecting the position of the rod 1 is based on a detection by reading the magnetic field. Inversions of polarities appear more or less regularly on the magnetic strip, and are matched with actual values measured during a calibration process. A matching table is thus constructed, it is specific to each device. When the rod 1 of the sensor device touches the part to be measured, the magnetic value read is linked to the corresponding value recorded in the memory of the microcontroller.
Information about the position of the rod is preferably transmitted in real time to software means able to calculate the movement thereof and therefore the movement of the sensor body thereof, between an initial position and the contact position with the part to be tested.
According to a second embodiment of the invention, such as schematised in
According to a third embodiment of the invention, and in order to simplify and understand the design of the sensor,
Of course, in any case, a reader 13 of the position of the rod 1 is provided, preferably fixed on the second electronic board 8.
Usefully, the device according to the invention can be equipped with means able to ensure the sealing thereof and/or the protection thereof in a hostile environment. Thus, a protective varnish can cover sensitive areas of the device, such as conductive parts, not covered and protected by the electronic board(s). Moreover, the areas 100 referenced in
Moreover, the device according to the invention can comprise a display unit able to display information such as: value of the last measurement; name of the sensor; name of a gauge; identification of the sensor; number of cycles carried out. In addition, an actuator 13 advantageously enables: to navigate in a menu in order to display certain information; to trigger a measurement; to declare a measurement as the original point or zero. Of course, many other displays and controls are possible.
A useful aspect of the invention consists of adapting a magnetised gasket on the sleeve 10 in order to quickly fix the sensor device on the part to be measured.
Other ergonomic, technical or additional characteristics can be defined by a skilled person without coming away from the scope of the invention.