Classifications

• • 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
  • G01D11/00—Component parts of measuring arrangements not specially adapted for a specific variable
  • G01D11/30—Supports specially adapted for an instrument; Supports specially adapted for a set of instruments
• • 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
  • G01D11/00—Component parts of measuring arrangements not specially adapted for a specific variable
  • G01D11/24—Housings ; Casings for instruments
  • G01D11/245—Housings for sensors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/02—Cleaning by the force of jets or sprays
• • 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
  • G01D3/00—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
  • G01D3/028—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups mitigating undesired influences, e.g. temperature, pressure

Definitions

• the present invention relates to the field of sensors, and more particularly relates to a fixing device for holding a sensor.
• Proximity sensors having a cylindrical shape limited by a proximal end and a distal end are known. These sensors can be capacitive, inductive, optoelectronic or optical fiber, for example, and most often have a circular cross section. Such sensors are for example used in a machine tool or on an automated production line to detect the presence of an object and / or measure the distance to which the object is located.
• tubular body lying along a median longitudinal axis between a first end and a second end and comprising a longitudinal through passage intended to receive said sensor
• a projecting extending radially inwardly and defining a cross sectional orifice of dimensions less than the dimensions of the cross section of the sensor.
• the tubular body is for example provided with an external thread on at least part of its outer surface to allow its attachment through a wall by means of a nut and a lock nut.
• the senor When using such a fixing device, the sensor is inserted into the longitudinal passage through the tubular body. At the end of its insertion, the distal end of the sensor abuts against the radial expansion, thus obstructing the orifice, and the axial immobilization means are operated to immobilize the sensor axially in the longitudinal passage through. The detection is carried out through the orifice defined by the radial expansion.
• the sensor may be disturbed by a messy environment, for example by projections of cutting oil, chips of material or filings deposited on the distal end of the sensor. These deposits can prevent the sensor from working properly.
• a sensor malfunctions, the machine tool or automated chain is immediately stopped to prevent a incident. A technician must then intervene to disassemble the sensor, clean it, reassemble it, check its operation, then restart the machine tool or automated chain.
• tubular body extending along a median longitudinal axis between a first end and a second end and comprising a longitudinal through passage intended to receive said sensor
• WO 97/45231 A1 provides for forming a continuous cylindrical protective barrier all around the sensing face of the sensor using a liquid or gaseous flow injected in an annular chamber formed between the sensor and the tubular body.
• This barrier is formed by the cylindrical axial flow of fluid exiting the tubular body in the form of a continuous ring all around the sensing face of the sensor. Introducing a stop by means of a radial expansion in contact with which the sensing face of the sensor would come, interrupt (or remove) this barrier and therefore deteriorate the desired protection of the sensor.
• the cylindrical protective barrier does not fully protect the sensing face of the sensor.
• a problem proposed by the present invention is to provide a fixing device for the holding of a sensor which makes it possible to reduce or even avoid the disturbances of the sensor by a messy environment, without significantly increasing the size of the device. which generally has little space in the environment.
• the present invention aims to provide a fixing device for holding a sensor for more effective protection of the sensor in a messy environment, and also to restore a sensor function after it has been rendered inoperative by the messy environment.
• the invention proposes a fixing device for holding a sensor having a cylindrical shape limited by a proximal end and a distal end, the fixing device comprising:
• tubular body extending along a median longitudinal axis between a first end and a second end and comprising a longitudinal through passage intended to receive said sensor
• a projecting portion extending radially inward and defining an orifice with a cross-section of dimensions smaller than the dimensions of the cross section of the sensor;
• the axial immobilization means are shaped so as to keep the distal end of the sensor at a predetermined minimum longitudinal distance from said expansion, so that a radial fluid conduction space is formed between the expansion and the distal end the sensor,
• the fixing device comprises means for supplying a fluid inside the tubular body and into the radial fluid conduction space between the expansion and the distal end of the sensor.
• the axial immobilization means themselves ensure the maintenance of the distal end of the sensor at a predetermined minimum longitudinal distance from said expansion, so that the front end surface of the distal end of the sensor can not come into contact with said expansion, leaving free a radial fluid conduction space which provides a function of conduction and deflection when fluid, such as air for example, is injected between the expansion and the distal end of the sensor: the radial development leads to least part of the flow radially inwards. This part of the fluid injected into the tubular body thus follows, after deflection by the radial expansion, sweep the front end surface of the distal end of the sensor before escaping through the opening defined by the expansion at the second end of the body tubular and left open by means of axial immobilization.
• This deflected flow of fluid on the distal end of the sensor makes it possible to better limit the risks of deposits on the front surface of the distal end of the sensor, which can cause a malfunction of the sensor, and even makes it possible to eject any deposits that may have formed. on the distal end of the sensor and causing the sensor to malfunction.
• the injection of fluid can be permanent during the operating time of the machine tool or the automated chain, or can be controlled automatically when a malfunction of the sensor is detected by the controller managing the machine tool or chain automated, or can be further controlled at regular intervals or not during the operating time of the machine tool or the automated chain.
• the means for supplying a fluid being formed inside the tubular body, the bulk of the fastening device is not increased, or very little.
• the injected fluid also enables the sensor to be effectively cooled, and in particular the distal end face surface of the sensor when the latter is exposed to strong heat sources through the orifice formed in the second end of the tubular body.
• the axial immobilization means may comprise axial abutment means comprising at least one abutment facet intended to receive the distal end of the sensor in abutment in order to maintain the distal end of the sensor at a predetermined longitudinal distance from said expansion.
• the axial abutment means make it possible to limit the penetration of the sensor into the longitudinal through passage in order to prevent the distal end thereof from coming into contact with the radial expansion. This prevents the distal end of the sensor from bearing against radial expansion and obstructs the orifice defined by it. It is also avoided that the longitudinal gap between the expansion and the distal end of the sensor is too large and prevents the expansion from effectively playing its role of deflector to deflect the fluid flow and direct it to the front surface of the sensor. distal end of the sensor. The radial fluid conduction space between the expansion and the distal end of the sensor is thus reliably preserved for a fluid injection sufficiently sweeping the front surface of the distal end of the sensor and then escaping through the orifice.
• the axial abutment means may comprise at least one outgrowth extending longitudinally from the blooming towards the first end.
• the predetermined longitudinal distance between the distal end of the sensor and the radial expansion is thus easily and precisely adjusted.
• the longitudinal through passage comprises: a first section comprising first support means shaped so as to bear against the cylindrical outer surface of the sensor,
• a second section following the first section towards the second end, having a cross section of dimensions greater than the dimensions of the cross section of the sensor and thus providing a radial chamber formed around the sensor when the sensor is engaged in the second section,
• a third section following the second section towards the second end, comprising second support means shaped so as to bear against the cylindrical outer surface of the sensor
• the means for supplying a fluid comprise:
• a radial passage formed in the side wall of the tubular body and for injecting a fluid into the radial chamber of the second section
• At least one longitudinal passage allowing the passage of a fluid from the second section to the fourth section in the presence of a sensor engaged in the third section.
• the fixing device is thus very compact and simple to manufacture by machining.
• the second support means may comprise a plurality of protuberances extending radially inward, separated from each other by a plurality of longitudinal passages allowing the passage of a fluid from the second section to the fourth section in the presence a sensor engaged in the third section.
• the protuberances allow to hold the sensor radially with a small clearance, defining between them a cross section of dimensions substantially equal to the dimensions of the cross section of the sensor. Between the protuberances are provided longitudinal passages for injecting fluid at a flow rate sufficient to clean the distal end of the sensor.
• the protuberances and longitudinal passages can be obtained simply and quickly by radial milling.
• the first support means comprise a cylindrical lateral surface with a cross-section of dimensions substantially equal to the dimensions of the cross section of the sensor.
• the first bearing means thus radially hold the sensor with a small clearance for good reliability.
• this low clearance allows only little (or no) fluid to pass between the first support means and the sensor, and in any case less than the amount of fluid that can be passed to the second end of the tubular body.
• the engagement of the sensor in the first support means is a sufficient obstruction of the longitudinal passage through so that the majority of the injected fluid, or all, is directed towards the second end of the tubular body and its radial growth.
• first bearing means similar to the second support means (thus easily passing the fluid towards the first end of the tubular body), but also using means of obstruction at least partial (or even total) of the first end of the tubular body, so that most (or all) of the fluid injected into the tubular body is directed towards the second end of the tubular body to be later directed by the development radial on the distal end of the sensor.
• the axial immobilization means may comprise an internal thread intended to cooperate with an external thread provided on the outer surface of the sensor.
• the internal thread of the axial immobilization means by its cooperation with the external threading provided on the outer surface of the sensor, allows reliable axial retention of the sensor in the longitudinal passage through, and with relative sealing so that most of the fluid injected, or all, is directed towards the second end of the tubular body and its radial development.
• the development can be annular.
• a scan of the distal end of the sensor is thus substantially uniform in all radial directions.
• the tubular body may be provided with an external thread on at least part of its outer surface.
• a method for cleaning and / or cooling a sensor having a shape cylindrical limited by a proximal end and a distal end comprises the following steps:
• tubular body lying along a median longitudinal axis between a first end and a second end and comprising a longitudinal through passage intended to receive said sensor
• a projecting portion extending radially inward and defining an orifice with a cross-section of dimensions smaller than the dimensions of the cross-section of the sensor
• a fixing device that has no axial immobilization means shaped so as to keep the distal end of the sensor at a predetermined minimum longitudinal distance from said expansion (as in the state of the prior art). ) but however comprising means for supplying a fluid inside the tubular body and to the vicinity of the blooming. It should be noted that such a fixing device may be patented as such, in particular by means of a divisional application.
• FIG. 1 is a perspective view of a first embodiment of fastening device according to the present invention, with a sensor inserted in the through passage of the tubular body;
• FIG. 1 is a longitudinal sectional view of the fixing device of Figure 1;
• Figure 3 is a detail view of Figure 2;
• FIG. 4 is a longitudinal sectional view of the fixing device of Figure 1, with the sensor out of the through passage of the tubular body;
• FIG. 5 is a cross-sectional view of the tubular body of the fixing device of FIG. 1;
• FIG. 6 is a perspective view of an oblique transverse section of the tubular body of the fixing device of FIG. 1;
• FIG. 7 is a longitudinal sectional view of a second embodiment of fastening device according to the present invention, with a sensor out of the through passage of the tubular body;
• FIG. 8 is a longitudinal sectional view of a third embodiment of fastening device according to the present invention, with a sensor outside the through passage of the tubular body;
• FIG. 9 is a perspective view of the fixing device of FIG. 8. DESCRIPTION OF THE PREFERRED EMBODIMENTS
• FIGS. 1 to 6 show a first embodiment of fastening device 1 according to the invention for holding a sensor 2.
• the sensor 2 has a cylindrical shape limited by a proximal end 2a and a distal end 2b to front end surface 20b.
• the fixing device 1 comprises:
• tubular body 3 extending along a median longitudinal axis I-I between a first end 3a and a second end 3b and comprising a longitudinal through-passage 4 intended to receive said sensor 2,
• the longitudinal axis II is median in that it is substantially located in the center of the longitudinal through passage 4.
• the tubular body 3 has an external thread 3c so as to cooperate with a nut 18 and a lock nut 19 for mounting through a wall of a machine tool or automated chain.
• an expansion 6 extends radially inwards (that is to say, approaching the median longitudinal axis II) and defines an orifice 7 with a cross section of dimensions smaller than the dimensions of the cross section of the sensor 2.
• the orifice 7 has a diameter D7 less than the diameter D2 of the distal end 2b of the sensor 2.
• the axial immobilization means 5 are shaped so as to maintain the distal end 2b of the sensor 2 at a predetermined minimum (non-zero) longitudinal distance E from said expansion area 6.
• the distal end 2b of the sensor 2 can thus not come into abutment against the expansion 6, which can thus reliably provide a function of injected fluid deflection, as will be explained below.
• the expansion 6 is annular so as to provide a sweep, substantially uniform in all radial directions, of the distal end 2b (and its end end surface 20b) of the sensor 2 by the injected fluid.
• the axial immobilization means 5 comprise a conical ring 8, elastically deformable, and intended to be pressed axially between a nut 9 cooperating with a conical bearing surface 10.
• the cooperation of the nut 9 with conical bearing surface 10 makes it possible to deform the conical ring 8 inwards (in other words by approaching the central longitudinal axis 1-1) to clamp the latter against the cylindrical outer surface of the sensor 2 and immobilize the latter axially according to the median longitudinal axis II.
• FIG. 2 shows more particularly that the fixing device 1 comprises means for feeding a fluid 1 1 inside the tubular body 3 and up to the immediate vicinity (upstream) of the expansion 6.
• the fluid supply means 1 1 more precisely make it possible to bring the fluid into the space E between the expansion 6 and the distal end 2b of the sensor 2 when the latter is inserted in the longitudinal through-passage 4.
• the axial immobilization means 5 also comprise axial abutment means 12, comprising at least one abutment face 13 intended to bear the distal end 2b of the sensor 2 in order to maintain the abutment.
• distal end 2b of the sensor 2 at a predetermined longitudinal distance E of said expansion 6.
• These abutment faces 13 are carried by protrusions 14 extending longitudinally from the opening 6 towards the first end 3a (or away from the second end 3b) of the tubular body 3.
• FIGS. 2 to 4 show more particularly that the longitudinal through-passage 4 comprises:
• a first section T1 comprising first bearing means 15 shaped so as to bear against the cylindrical outer surface of the sensor 2,
• a second section 12 following the first section T1 towards the second end 3b, having a cross section of dimensions (diameter DT2) greater than the dimensions of the cross section (diameter D2) of the sensor 2 and thus providing a radial chamber 16 formed around the sensor 2 when it is engaged in the second section T2,
• a fourth section T4 between said expansion 6 and said at least one abutment face 13.
• the means for supplying a fluid 11 comprise:
• a radial passage 20 formed in the side wall of the tubular body 3 and allowing the injection of a fluid (liquid or gaseous) into the radial chamber 16 of the second section T2,
• At least one longitudinal passage 21 allowing the passage of a fluid from the second section T2 to the fourth section T4 in the presence of a sensor 2 engaged in the third section T3 (see Figure 3).
• the realization of the radial chamber 16 by means of a bore of diameter DT2 greater than the diameter D2 of the sensor 2 is only one of the possibilities and is not limiting.
• a radial chamber 16 comprising one or more longitudinal grooves formed in the cylindrical lateral wall of a bore, in the second section, of diameter substantially equal to the diameter D2 of the sensor 2.
• the second support means 17 comprise three protuberances 22 extending radially inwards (in other words, approaching the median longitudinal axis M), separated from each other by a plurality of longitudinal passages 21 allowing the passage of a fluid from the second section T2 to the fourth section T4 in the presence of a sensor 2 engaged in the third section T3.
• the three protuberances 22 define between them a housing of diameter D22 substantially equal to the diameter D2 of the sensor 2.
• the protuberances 22 and longitudinal passages 21 are obtained by radial milling, that is to say by removal of material in a tool movement away from the median longitudinal axis I-I.
• the first support means 15 comprise in turn a cylindrical lateral surface 23 with a cross section of dimensions (diameter D15 or DT1) substantially equal to the dimensions (diameter D2) of the cross section of the sensor 2.
• the sensor 2 When it is mounted in the fixing device 1, the sensor 2 is inserted in the direction of the median longitudinal axis I-I in the longitudinal through-passage 4 (arrow 29 in FIG. 4). The insertion of the sensor 2 is stopped by the support of the distal end 2b of the sensor 2 against the abutment facets 13 (FIG. 2). A longitudinal gap E (that is to say along the longitudinal axis I-I) predetermined minimum non-zero is thus maintained between the distal end 2b and the radial expansion 6, allowing an output of the injected fluid at a satisfactory rate. The nut 9 is then actuated to axially immobilize the sensor 2 in cooperation with the conical ring 8 and the conical bearing surface 10.
• a longitudinal gap greater than the minimum predetermined longitudinal gap E defined by the axial abutment means 12 may be provided by maneuvering the axial immobilization means 5 (conical ring 8, nut 9 and conical bearing surface 10) before the 2b distal end of the sensor 2 comes into contact with the abutment facets 13. It is nevertheless necessary that the distal end 2b of the sensor 2 is sufficiently close to the bloom 6 so that the latter effectively plays its role of baffle towards the front end surface 20b.
• a fluid is injected into the tubular body 3 through the radial passage 20. Its path is illustrated by the broken line referenced 28.
• the first end 3a being obstructed in an almost watertight manner in that the sensor 2 is engaged in the first support means 15, the fluid (liquid or gaseous) then enters the radial chamber 16 and progresses in the longitudinal direction II towards the second end 3b of the tubular body 3 along the entire length of the second section 12.
• the injected fluid enters the three longitudinal passages 21 and thus passes through the third section T3 to reach the radial fluid conduction space axially included along the longitudinal axis median II between the expansion 6 and the distal end 2b of the sensor 2 (corresponding to the fourth section T4).
• This radial fluid conduction space is reliably preserved by means of axial immobilization means 5.
• the fluid is then deflected radially inwards (in other words by approaching the median longitudinal axis II) by the radial expansion 6 acting as a deflector to lick the flow end end surface 20b distal of the sensor 2.
• the fluid then escapes through the orifice 7.
• the distal end surface 20b is thus licked by the flow of the injected fluid, which makes it possible to better prevent its fouling, or even to clean it after fouling.
• the fluid flow also makes it possible to effectively cool the sensor 2, and in particular its distal end surface 20b when the latter is exposed to strong sources of heat through the orifice 7.
• the fluid injection can be permanent during the operating time of the machine tool or the automated chain, or can be controlled automatically when a malfunction of the sensor 2 is detected by the machine tool controller or automated chain, or can be further controlled at regular intervals during the operating time of the machine tool or the automated chain (cleaning and / or preventive cooling). Control at regular intervals is even more feasible with the device according to the present invention that the deflection of the fluid by the blooming 6 not only allows to better limit the risks of a fouling of the distal end 20b end surface, but also to clean it after fouling.
• the second embodiment of fixing device 1 illustrated in FIG. 7 is very similar to the first embodiment of fastening device 1 illustrated in FIGS. 1 to 6.
• the numerical references used for the description of the first embodiment thus designate the same elements as in the second embodiment.
• the axial immobilization means 5 comprise, in the first section T1, an internal thread 24 intended to cooperate with an external thread 2c provided on the outer surface of the sensor. 2.
• a nut 25 cooperating with the external thread 2c can also be used to limit the screw-in penetration of the sensor 2 into the tubular body 3 in order to maintain the distal end 2b of the sensor 2 at a predetermined longitudinal distance 6.
• the nut 25 can thus be used when the abutment faces 13 define a minimum predetermined non-zero predetermined longitudinal gap away from the expansion 6 (or when it is desirable to have a gap more important between the distal end 2b of the sensor 2 and the expansion 6 than that provided by the abutment facets 13).
• the second embodiment of fixing device 1 comprises an external thread 3c of the tubular body 3 so as to cooperate with a nut 18 and a locknut 19 for its mounting through a wall of a machine tool or automated chain.
• the third embodiment of fastener 1 illustrated in Figures 8 and 9 is also very similar to the first and second fastener embodiments 1 illustrated in Figures 1 to 6 and 7.
• the numerical references used for the description of the third embodiment thus designate the same elements as in the first and second embodiments.
• the tubular body 3 instead of an external thread 3c provided on the tubular body 3 for attachment to a machine tool or automated chain, the tubular body 3 comprises a radial expansion 26 in which is formed an oblong hole 27 intended to be traversed by one or more screws 30 for screwing into the machine tool or automated chain.
• tubular body 3 of the third embodiment of fixing device 1 may alternatively comprise means axial immobilization 5 similar to those used in the first embodiment (with the conical ring 8, the nut 9 and the tapered seat 10) to receive sensors 2 without external thread 2c on their outer surface.
• the penetration of the sensor 2 can be stopped before the abutment of the distal end 2b against the abutment facets 13 by the coming of the nut 25 bearing against the first end 3a of the tubular body 3 (case where the predetermined minimum non-zero longitudinal distance afford defined by the abutment facets 13 is considered insufficient to allow a sufficient flow of fluid).
• the first end 3a of the tubular body 3 is substantially sealed by the fact that the sensor 2 is screwed into the internal thread 24 of the axial immobilization means 5, so that the fluid (Liquid or gaseous) penetrating into the radial chamber 16 also progresses in the longitudinal direction II towards the second end 3b of the tubular body 3 over the entire length of the second section T2.
• tubular body 3 extending along a median longitudinal axis I-I between a first end 3a and a second end 3b and comprising a longitudinal through-passage 4 intended to receive said sensor 2,
• a projecting portion 6 extending radially inwards and defining an orifice 7 with a cross-section of dimensions smaller than the dimensions of the cross-section of the sensor 2,
• said longitudinal gap non-zero between the distal end 2b of the sensor 2 and said expansion 6 may be formed by not pushing the sensor 2 to come into contact with the expansion 6.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Fluid Pressure (AREA)
• Measuring Temperature Or Quantity Of Heat (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

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• 2016
  • 2016-09-12 FR FR1658483A patent/FR3055963B1/fr not_active Expired - Fee Related
• 2017
  • 2017-09-08 JP JP2019535996A patent/JP6999677B2/ja active Active
  • 2017-09-08 CN CN201780055530.8A patent/CN109690252B/zh active Active
  • 2017-09-08 EP EP17768523.7A patent/EP3510359B1/fr active Active
  • 2017-09-08 US US16/330,404 patent/US11391605B2/en active Active
  • 2017-09-08 WO PCT/IB2017/055422 patent/WO2018047105A1/fr not_active Ceased

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