DEVICE FOR INSPECTING THREADED ELEMENTS AND A CORRESPONDING INSPECTION METHOD - Patent application

Abstract

Dimensional measuring device for a screw element (6), the device comprising a first laser line sensor (3) and a second laser line sensor (4) having a second optical measurement direction, the second optical measurement direction forming a non-zero angle A with the first optical measurement direction in a plane containing the first optical measurement direction, the first laser line sensor (3) and the second laser line sensor (4) being movably mounted on a framework (2) and having at least one measurement path allowing acquisition of geometric data of the screw element (6), the path passing through a calibration gauge (5) and being able to pass through a portion of the screw element (6), the device comprising an electronic unit arranged to construct a complete profile from a first part profile from the first laser line sensor (3) and a second part profile from the second laser line sensor (4) in response to at least one measurement performed on the calibration gauge (5).

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for measuring the thread form of a threaded element, and more particularly to an apparatus and method for measuring the thread form of an element such as a threaded joint in an oil country tubular good, a carbon dioxide or hydrogen storage tubular good, or a geothermal tubular good.

[0002] The thread form measurement determines the thread form profile of the axial helical direction of the thread element, and the thread element is measured based on the thread form profile. For example, in the case of an oil country pipe thread, the thread element includes the following elements: A threaded zone is a surface portion of a threaded element that is defined on one side by a first thread end and on the other side by a second end of the threads.

[0003] The threaded element has threaded ends that are complementary and allow a male tubular component (pin) to be connected to a female tubular component (box). There is therefore a male threaded end and a female threaded end. The threaded zone can have a thread that is said to be complete or a thread that is said to be incomplete, the incomplete thread having a cross section that corresponds to the incomplete cross section of the corresponding complete thread, for example, reduced in height.

[0004] A screw is a group of threads, male or female, created by a geometric profile that moves along a surface according to a helical motion.

[0005] A thread, when viewed in cross section, comprises a series of regularly spaced teeth or threads, whereby in cross section a "tooth" is understood to be the narrow section extending from the base of the piercing flank to the base of the load flank, said piercing flank and said load flank being joined by a crest.

[0006] Within a thread end, a male or female thread section, when viewed in cross section, has a straight line segment connecting the mid-height of the load flanks of successive threads, said segment forming a constant angle with the axis of the thread end. If this angle is zero, the thread section is said to be cylindrical. If this angle is non-zero, the thread section is said to be conical. The angle can be expressed in degrees, radians, or a percentage. The thread angle is equal to twice the angle formed between the aforementioned straight line segment and the axis of the thread end, or the thread angle is equal to the angle at the apex of the cone formed by the straight line segment as a generatrix rotated about the axis of the thread end.

[0007] The thread may be cylindrical, i.e., have a generatrix parallel to the axis of the threaded end, or the thread may be conical, i.e., have a generatrix forming a non-zero angle with the axis of the threaded end.

[0008] A thread comprises two flanks, a puncture flank and a load flank, a root and a crest.

[0009] The puncture flanks are the thread surfaces that can come into contact when the threads of the male and female threaded components engage with each other. They therefore correspond to the flanks facing the free end of the tubular component in question.

[0010] The load flanks are the thread surfaces that can come into contact when the threaded joint is subjected to axial tension. They therefore correspond to the flanks facing opposite the free end of the tubular component in question.

[0011] Positive or negative angle(s) - Conventionally, within the context of the present invention, anti-trigonometric directions are used, which are also clockwise directions. Thus, positive angles go in a clockwise direction, and conversely, negative angles go in a counterclockwise direction.

[0012] The machining of pipes to produce threads involves the presence of a thread pitch. The concept of thread pitch must be understood in light of the standard ISO 5408:2009 on the definition of threads. Thread pitch corresponds to the axial distance over one revolution between two consecutive points, such as two consecutive crests or two consecutive valleys, of a thread, and this distance is referred to as "P." For assembly and use of fittings, thread pitch must be controlled to allow threading between the male thread and the corresponding female thread. [Background technology]

[0013] Conventional techniques for measuring the thread geometry of threaded elements are known, based for example on tangential illumination of the thread and image capture by an optical sensor facing the light source to generate a two-dimensional image. While there are variations on the orientation of light radiation and the use of mirrors, these methods have the disadvantage of lacking precision and being suitable for only a limited number of connection types. Indeed, as soon as the thread flank has a negative angle, it is impossible to project its complete profile, making direct measurement impossible.

[0014] Furthermore, even if a screw is illuminated with parallel light in a direction tangential to the helix of the screw, the path of the parallel light is linear and not helical, so the thread profile captured by the parallel light will interfere with the surfaces adjacent to the target section and will differ from the actual profile, which is helical.

[0015] Furthermore, the device according to the present invention is portable. Summary of the Invention

[0016] The invention is based on the use of two optical sensors with different acquisition directions and the possibility of combining the measurement data of the two sensors to reconstruct the morphology of the measured screw, thus reducing the inspection cycle time and allowing the profile to be digitized and verified.

[0017] According to one embodiment, the present invention provides a dimensional measurement device for a threaded element, the device comprising a framework, the framework comprising a first laser line sensor having a first optical measurement direction and a second laser line sensor having a second optical measurement direction, the second optical measurement direction forming a non-zero angle with the first optical measurement direction in a plane containing the first optical measurement direction, the first laser line sensor and the second laser line sensor being movably mounted on the framework and having at least one measurement path allowing acquisition of geometric data of the threaded element, the path passing through a calibration gauge and being able to pass through a portion of the threaded element, the device being configured to measure a dimension of the threaded element in a main axis direction. and an electronics unit arranged to construct a first partial profile from the first laser line sensor and a second partial profile from the second laser line sensor, the electronics unit being arranged to construct a complete profile from the first partial profile and the second partial profile in response to the respective positions of the first laser line sensor and the second laser line sensor and in response to at least one measurement performed with a calibration gauge.

[0018] It is therefore possible to propose an apparatus which makes it possible to test and measure the ends of threaded elements very accurately, while at the same time making it possible to carry out measurements in poorly monitored environments, the positioning of the threaded element relative to the apparatus being mechanically controlled and sources of error related to positioning being compensated for in each measurement operation by calibration means incorporated into the operation.

[0019] According to embodiments, such a device may have one or more of the following features:

[0020] According to one embodiment, the angle is between 30° and 70°, preferably between 40° and 60°, which makes it possible to measure a wide variety of threads, including those with hook-type profiles or with dovetail-type profiles.

[0021] According to one embodiment, the first and second laser line sensors are translationally mounted on a framework, so that the path of the sensors relative to the part being measured is simple and it is possible to compensate for positioning offset errors of the screw elements relative to the machine.

[0022] According to one embodiment, the calibration gauge comprises a surface defining a predetermined reference length, which makes it possible to provide dimensional markers for the calibration process during the measurement operation.

[0023] According to one embodiment, the calibration gauge comprises a support surface arranged to contact the end face of the threaded element to be measured, which allows for minimizing positioning errors of the threaded element relative to the device and simplifies the calibration procedure.

[0024] According to one embodiment, the device comprises a positioning wedge arranged to support the threads of the threaded element, which simplifies and makes the positioning of the device on the threaded element more reliable.

[0025] According to one embodiment, the positioning wedge has a tapered stabbing surface axis and is provided with a tapered stabbing surface that can contact the threads of the threaded element, thereby making the positioning wedge and device compatible with threaded elements having conical threads.

[0026] According to one aspect, the support surface is perpendicular to the axis of the tapered insertion surface of the positioning wedge.

[0027] According to one embodiment, the calibration gauge comprises a piercing flank reference surface, a load flank reference surface, an axial length reference surface, and a radial length reference surface, which allows defining a reference length for calibration that corresponds to a nominal characteristic of the thread feature to be measured, thereby improving measurement accuracy.

[0028] According to one embodiment, the calibration gauge comprises a longitudinal reference extension defining a reference length Dr, and the electronic unit is arranged to determine a measurement path correction factor associated with the paths of the first and second laser line sensors, thereby allowing the measurement value to be corrected according to a positioning offset error of the screw element relative to the device.

[0029] According to one embodiment, the electronic unit is arranged to compare the digital thread profile, including the minimum and maximum dimensions, with the complete profile, and the electronic unit is configured to generate a thread compatibility result, which can provide a thread element compatibility result to a user.

[0030] According to one aspect, the electronic unit is arranged to perform dimensional measurements of the surface of the end of the screw element.

[0031] The present invention also provides a method for dimensional measurement of an end of a threaded element, comprising: Attaching a measuring device as described above to the threaded element; performing data acquisition by a first laser line sensor and a second laser line sensor on the measurement gauge; determining measurement correction factors and storing them in the memory of the electronic unit; performing a second acquisition of data of the end of the threaded element by the first laser line sensor and the second laser line sensor; generating a first partial profile from a first data set resulting from a second acquisition of data by a first laser line sensor; generating a second partial profile from a second data set resulting from a second acquisition of data by a second laser line sensor; generating a complete profile from the first partial profile, the second partial profile provided, and the measurement correction factors.

[0032] This method allows the dimensional characteristics of the threaded elements to be measured and verified with a very high degree of accuracy by simple manipulations.

[0033] The present invention will be better understood and other objects, details, features and advantages will become more clearly apparent in the course of the following description of some particular embodiments thereof, given by way of example only and not by way of limitation, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a perspective view of the device in a measuring position on a threaded element. [Figure 2] 1 is a perspective view of a calibration gauge according to the present invention; [Figure 3] FIG. 1 is a perspective view of a positioning wedge according to the present invention. [Figure 4] 2 is a schematic cross-sectional view of a variation of an embodiment of the device of FIG. 1 in the context of a female threaded element. DETAILED DESCRIPTION OF THE INVENTION

[0035] The measuring device 1 according to the invention as seen in Figure 1 comprises a framework 2 comprising a generally rectangular table 10 having a handle 13 attached to a first side thereof which an operator can manipulate to push the table towards the screw element 6 or to pull the device away from the screw element 6. Opposite the first side, the table 10 comprises at least one jack 12 connected to a positioning wedge 8. In the embodiment shown, the device comprises two jacks 12.

[0036] The locating wedge 8, shown alone in FIG. 3, has an insertion surface 9 arranged to contact the threads of the threaded element 6. In the illustrated embodiment, the threaded element has a tapered external thread. Thus, the locating wedge 8 has a tapered insertion surface 9 with a taper that substantially corresponds to the taper of the thread, with the tapered insertion surface 9 facing inward to contact the threads of the external threads of the threaded element 6 and the threads facing outward. This tapered insertion surface 9 allows the device to be aligned with the axis of the thread. The tapered insertion surface 9 has a larger inner diameter and a smaller inner diameter so that the tapered insertion surface 9 lies on the complete thread of the threaded element 6. In fact, the tapered insertion surface 9 must rest on the complete thread of the threaded element 6. It will be understood that the locating wedge 8 is dimensioned according to the connection model on which the thread is to be tested, more specifically, according to the taper of the thread of the connection model. Thus, for example, there is a positioning wedge adapted to a conical connection of type VAM (Copyright) TOP 7-5 / 8, another positioning wedge adapted to a conical connection of type VAM (Copyright) 21 5-3 / 4, or a cylindrical connection of type API, etc. The positioning wedge can therefore be exchanged for another wedge on the device according to the invention. The positioning wedge can also be adapted to several connection types.

[0037] The positioning wedge 8 is cut out so that the threads are visible in an orientation corresponding to the measurement path taken by the dimensional sensors 3,4.

[0038] The positioning wedge 8 allows the end of the threaded element 6 and the calibration gauge 5 to be positioned at the focal depth of the dimensional sensor so that the focal depth of the dimensional sensor's laser is constant regardless of the diameter of the threaded element 6. This focal depth can vary between 5 mm and 200 mm, but is preferably between 5 mm and 50 mm. This makes it possible to avoid changing the position of the dimensional sensor in the direction perpendicular to the table (z).

[0039] The apparatus of FIG. 1 comprises two jacks or slide pins 12 which connect the positioning wedge 8 to the table 10 .

[0040] Once the operator has positioned the device according to the invention at one end of the screw element 6, the locating wedge 8 is brought around the thread of the screw element 6 and the operator then pushes the device towards the screw element 6 using the handle 13, which makes it easy for the operator to grasp and position the device in place. The locating wedge 8 is pressed against the thread until the puncture surface 9, which comes to bear against the thread of the screw element 6, opposes any further axial movement of the locating wedge 8. The operator can continue to push the device towards the screw element 6 and the jack or slide pin 12 until the support surface 52 of the calibration gauge 5 comes into contact with the end face of the screw element 6, so that the locating cone is positioned on the full thread.

[0041] More precisely, contact between the end of the threaded element 6 and the end of the table 10 is established between the end of the threaded element 6 and a calibration gauge 5 attached to the table 10. The calibration gauge 5 can be seen in detail in FIG. 3. The calibration gauge 5 is a particularly precisely machined part, several dimensions of which are completely known and stored in the memory of the electronic unit of the device 1. The calibration gauge 5 has a transverse portion 51, which serves, on the one hand, to position and fix the calibration gauge 5 on the table 10, and, on the other hand, its flat front or support surface 52 serves to contact the end of the threaded element 6. The calibration gauge 5 has a longitudinal portion 53 with a reference length whose dimensions are completely known. The reference length is defined by a surface. These lengths are therefore predetermined, serve as references for the device, and are stored in the memory of the device's electronic processing unit. The reference surface is positioned to allow the device to correct the data acquired by the dimensional sensors 3, 4, which depend on the position and orientation of the aforementioned dimensional sensors 3, 4 relative to the threaded element 6 and the calibration gauge 5. The correction is determined from the measurements carried out by the dimensional sensors 3, 4 on the calibration gauge 5 and a comparison of the measurements carried out with a predetermined reference length value. A correction factor can be calculated from this comparison. Thus, starting from the first measurement carried out on the calibration gauge 5, the data acquisition is corrected for the measurements carried out on the thread of the thread element 5 with the correction factor so calculated.

[0042] The calibration gauge 5 is positioned on the measurement path of the dimensional sensors 3, 4 so as to allow calibration with each measurement operation on the threaded element 6.

[0043] The calibration gauge 5 comprises a support surface 52 on its transverse portion 51 arranged to contact the end face of the threaded element 6. The support surface 52 is perpendicular to the axis of the tapered insertion surface 9 of the locating wedge 8. The support of the support surface 52 against the end face of the threaded element 6 in combination with the action of the locating wedge 8 on the thread makes it possible to lock a device onto the threaded element 6 to perform measurements and to define orthogonal dimension markers.

[0044] In particular, the calibration gauge 5 includes a piercing flank reference surface 54, a load flank reference surface 55, an axial length reference surface 56, and a radial length reference surface 57. Thus, the piercing flank reference surface 54 has substantially the same orientation as the piercing flank surface of the thread of the thread element 6 to be measured, and similarly, the load flank reference surface 55 has substantially the same orientation as the load flank surface of the thread of the thread element 6. This allows for improved measurement accuracy for the thread flank. The axial length reference surface 56 is defined by two surfaces separated from the axial length reference surface. The length of the axial length reference surface 56 corresponds to the reference axial distance, allowing for improved measurement accuracy for the crests and roots of the thread. The radial length reference surface is realized by a recess perpendicular to the axial length reference surface 56.

[0045] The longitudinal portion 53 is located contiguous with the cut-out portion of the positioning wedge 8. In other words, the longitudinal portion 53 is on the measurement path of the dimension sensors 3, 4.

[0046] The device also comprises a longitudinal reference extension 11 on the calibration gauge 5. This longitudinal reference extension 11 has known dimensions so as to define on the one hand the surfaces of the longitudinal reference extension 11, for example the surface facing the transverse portion 51, and on the other hand a reference distance Dr delimited by the surfaces of the transverse portion 51. This makes it possible to determine the deviation of the path of the dimensional sensors 3, 4 from a theoretical path parallel to the axis of the threaded element by the measurements performed.

[0047] The positioning wedge 8 and the calibration gauge 5 allow the device to be repeatedly positioned on the screw element 6 and to make the main axis of the screw element 6 coincide as much as possible with the measurement axis of the device according to the invention, i.e. to minimize the deviation of the measurement axis relative to the main axis of the screw element 6.

[0048] In the embodiment of FIG. 1, the two dimensional sensors 3 and 4 are identical and are laser line sensors or laser profilers. The prototype was constructed using a GOCATOR 2510 sensor manufactured by LMI Technologies. The two dimensional sensors 3 and 4 are mounted on supports arranged to allow three-axis position and orientation adjustment. The dimensional sensors 3 and 4 are also translationally mounted to move in a direction substantially corresponding to a principal direction or axis (x) so that the beams of each of the two laser profilers can pass through all target areas of the end of the threaded element, i.e., one or more threads, any functional surfaces and other portions of the end of the threaded element, or even the entire end of the threaded element. The displacement of the dimensional sensors 3 and 4 along their translational axes is measured by linear encoders.

[0049] The laser line sensor emits a laser beam centered in the line of sight so that its projection forms a line on the surface to be measured. The laser measurement is synchronized with the measurement of an optical encoder, which determines the longitudinal position along the main axis (x). This allows the complete profile to be reconstructed from two plotted partial profiles digitized by the laser line sensor. The distance between the points on the projected line is evaluated by an internal camera-type image capture device, and the laser beam is emitted in pulses, and the time of flight of the light beam is measured to determine the distance from the dimensional sensor. The line of sight is substantially perpendicular to the face of the laser emitter.

[0050] Attached to the measuring device, orthogonal markers called measurement markers (O, x, y, z) are defined. The primary axis (x) is substantially aligned with the primary axis x' of the thread of the threaded element 6 to be measured. This alignment is physically obtained by placing a locating wedge 8 on the threaded element. The secondary axis (y) lies in a plane parallel to the top surface of the calibration gauge 5, and the tertiary axis (z) is perpendicular to the top surface of the calibration gauge 5.

[0051] The respective viewing direction or direction of each optical measurement sensor forms an angle A between the first and second viewing direction of 30° to 70° in a plane containing the primary and tertiary axes (O, x, z). Preferably, the angle A is between 40° and 60°. Such an angle between the two directions makes it possible to measure the geometric data of the thread flank, regardless of whether the thread flank has a negative or positive angle. In particular, it is possible to perform measurements on threads with a hook-type profile or a dovetail-type profile. It is also possible to perform measurements on variable-pitch threads, which are more often associated with dovetail-type profiles.

[0052] The respective line of sight directions of each dimensional sensor are opposed to each other, ie the line of sight direction of a first sensor is opposite to the line of sight direction of a second sensor in projection onto the principal axis (x).

[0053] Each line of sight can form a non-zero offset angle B in the plane containing the major (x) and secondary (y) axes. This angle is as close to zero as possible, but in practice is naturally imperfect. To improve the accuracy of the measurement, this offset angle is compensated for by a calibration step in the measurement process, which includes performing the measurement step on a calibration gauge.

[0054] Furthermore, the displacements of the dimensional sensors 3, 4 are not strictly parallel to the main axis x' of the thread element being measured, but rather occur in a direction that can have a first deflection angle α relative to the first axis (x) in the plane (O, x, y), a second deflection angle β relative to the first axis (x) in the plane (O, x, z), and a third deflection angle γ relative to the third axis (z) in the plane (O, y, z). A first measurement step on the calibration gauge 5 allows for the determination of correction factors depending on the first deflection angle α, the second deflection angle β, and the third deflection angle γ.

[0055] The following steps involve obtaining a first set of measurements by the first dimensional sensor 4 and a second set of measurements by the second dimensional sensor 5. The sets of measurements relate to the threads of the threaded element, but may also relate to other functional surfaces of the threaded element, such as stop or sealing surfaces. These surfaces have the important function of cooperating with corresponding surfaces of the corresponding threaded element to ensure assembly torque and tightness against liquids and / or gases and therefore must meet very precise dimensional criteria.

[0056] When measurements are performed on a threaded element by the dimensional measuring device 1, the electronic unit is configured to receive measurements from the first dimensional sensor 3 and an output representative of the positioning of the first dimensional sensor 3 from the linear encoder, the electronic unit being arranged to reconstruct a first part profile of the threaded element under investigation. Similarly, the electronic unit is arranged to receive measurements from the second dimensional sensor 4 and an output representative of the positioning of the second dimensional sensor 4 from the linear encoder, the electronic unit being arranged to reconstruct a second part profile of the threaded element under investigation.

[0057] During the measurement of the thread element, the first and second dimensional sensors 3, 4 also perform measurements of the thread element and of the calibration gauge 5. The electronic unit is arranged to record the measurements performed on the calibration gauge 5 and to determine from the measurements performed measurements on surfaces defining the reference lengths, including reference values ​​of the piercing flank reference surface 54, the load flank reference surface 55, the axial length reference surface 56 and the radial length reference surface 57, and to determine correction factors by comparing the measurements performed on these surfaces with the actual length values ​​of the reference surfaces.

[0058] During the measurement of the thread element, the first and second dimension sensors 3, 4 also perform a measurement of the longitudinal reference extension 11 and determine a measured reference length value Dr'. By comparing the measured reference length value Dr' with the reference length Dr, the electronic unit is arranged to determine a measurement path correction factor associated with the paths of the first and second dimension sensors 3, 4. This factor makes it possible to compensate for the difference between the main axis of the thread element and the displacement axis of the dimension sensors 3, 4.

[0059] The displacement of the dimensional sensors 3, 4 can be performed at variable speeds, for example at a first, lower displacement speed to obtain a denser acquisition of measurement points, and at a second displacement speed higher than the first, at which it is not necessary to have a large number of measurement points on the surface. On functional surfaces such as stop or sealing surfaces, or on surfaces that are highly inclined with respect to the main axis (x), it is advantageous to have a slower speed and therefore a larger number of measurement points.

[0060] The electronic unit is arranged to construct a complete profile of the thread element by combining the first partial profile and the second partial profile after the measurement data has been processed taking into account the correction factor.

[0061] The electronics unit is arranged to overlay the complete profile with the digitized profile, which includes two profile traces, a maximum profile and a minimum profile, that define a profile envelope, and the electronics unit is arranged to display a matching result to the user when the complete profile is located entirely within the envelope, and to display an unmatched result when the complete profile is not entirely within the envelope.

[0062] The electronic unit is arranged to allow the complete profile to be compared to a reference geometry.

[0063] The first part profile may include measurement points on the thread crest, thread root, and one of the flanks, e.g., the puncture flank, due to the orientation of the first laser line sensor relative to the thread, while the second part profile may include measurement points on the thread crest, thread root, and other flanks, as well as on an exemplary given load flank. Thus, the first and second part profiles may have measurement points on common portions of the measured surface and measurement points on different portions of the measured surface due to the different and opposite orientations of the two laser line sensors. Combining the first and second part profiles then reveals groups of complementary and overlapping points. The complete profile includes measurement points on all surfaces under investigation as a combination of the two part profiles, corrected after the data has been processed.

[0064] The device according to the invention therefore makes it possible to implement a method for the dimensional measurement of the end of a threaded element 1, said method comprising the following successive steps:

[0065] First, the device 1 is brought over the threaded element 6 and attached to it so that the positioning wedge 8 is positioned on the thread, more precisely on the thread of the thread of the threaded element 6, more precisely on the complete thread. This positioning is carried out by introducing the positioning wedge 8 axially around the end of the threaded element 6 until it opposes any further displacement, and then the framework is pushed towards the end of the threaded element 6 by the operator using the handle 13 so that the jack 12 is compressed and until the stop face 52 of the calibration gauge 5 comes into contact with the end face of the threaded element 6. The measuring device 1 is thus positioned to minimize any offset between the axis of the threaded element 6 and the main axis x of the marker attached to the measuring device.

[0066] Secondly, a data acquisition phase is initiated during which the dimensional sensors 3, 4 move along a linear path passing through the measuring gauge and the surface of the threaded element 6 to be measured, said surface comprising at least one thread, optionally a stop surface and optionally further a sealing surface.

[0067] A data acquisition step is performed on the measurement gauge 5. Then a step is performed to determine a measurement correction factor by comparing a predetermined value corresponding to the actual value of the dimension of a particular surface of the calibration gauge 5 with the value measured on said surface by the dimension sensors 3, 4.

[0068] A data acquisition step is performed on one or more surfaces of the threaded element to be measured, said one or more surfaces comprising at least one thread, optionally a stop surface and optionally further a sealing surface, to obtain a first part profile resulting from measurements performed by the first dimensional sensor 3 and from the linear encoder, and to obtain a second part profile resulting from measurements performed by the second dimensional sensor 4.

[0069] The partial profiles are then combined to form the complete profile after correction has been applied with the measured correction factor.

[0070] The complete profile can then be subjected to a filtering or smoothing operation.

[0071] The resulting complete profile is then compared to a digital profile representing the envelope of the minimum and maximum dimensions of the thread profile to obtain a thread compatibility result that is positive if the complete profile is completely contained within the envelope defined by the digitized profile and negative if the opposite is true.

[0072] Finally, dimensional measurements can be performed on the complete profile without implying any limitations, such as determining the radius of curvature (by the circle inscription method), or directly measuring straight lines between points on the profile.

[0073] Figure 4 shows a schematic representation of a variation of one embodiment of the device of Figure 1 in the context of a female screw element, i.e., having a thread on its internal surface. In Figure 4, elements that are identical to or perform the same functions as elements described above in relation to Figures 1-3 have the same reference numerals.

[0074] Within the context of a female large dimension threaded element 6 (not shown), the measuring device 1 is similar to the measuring device 1 described above, with the orientation of the dimensional sensors 3, 4 adapted to emit a laser beam in the direction of the thread of the threaded element 6, optionally in the direction of the stop faces and optionally also in the direction of the sealing faces. A large dimension threaded element 6 is understood to be a threaded element that allows the dimensional sensors 3, 4 to be inserted into the threaded element 6 with a minimum distance between them and the surface or surfaces of the threaded element 6 to be inspected. Typically, the distance between the dimensional sensors 3, 4 and the surface or surfaces to be inspected must be greater than the start of the measurement range of the dimensional sensors 3, 4.

[0075] However, if the inner diameter of the threaded element 6 does not allow the dimensional sensors 3, 4 to be inserted with a distance between said dimensional sensors 3, 4 and the surface or surfaces to be inspected that is greater than the measurement range start distance of said dimensional sensors 3, 4, the measuring device 1 comprises a mirror 17 (see FIG. 4 ) for directing the laser beam emitted by the dimensional sensors 3, 4 towards the surface or surfaces on the threaded element 6 to be inspected. The dimensional sensors 3, 4 are then mounted on the framework 2 so as to emit the laser beam in the direction of the mirror 17, which is movably and orientably mounted on the measuring device 1 for redirecting the laser beam.

[0076] The measuring device 1 comprises a displacement and guide means for a mirror 17 and, in the embodiment shown in Figure 4, a guide rail 18. This displacement and guide means is inserted into the threaded element 6 when the measuring device 1 is positioned on the threaded element 6, typically in a manner similar to the positioning of the measuring device described above in relation to Figures 1 to 3, with the tapered insertion surface and support surface of the positioning wedge supporting the complete thread and the end face of the threaded element 6, respectively.

[0077] The mirror 17 is mounted on the aforementioned guide rail 18 so that it can be moved along the aforementioned guide rail 18, for example by an ad hoc motor. The position of the mirror 17 is further controlled, for example by a linear encoder, in a manner similar to the control of the position of the dimensional sensors 3, 4 of Figures 1 to 3. The dimensional sensors 3, 4 are directed to emit a laser beam in the direction of the respective mirror 17. This laser beam is then reflected by the aforementioned mirror 17 to strike one or more surfaces to be inspected, for example the gauge, the thread of the screw element 6, the stop face and / or the sealing face.

[0078] Advantageously, the mirror 17 further has a configurable orientation, for example by means of an orientable mirror support or a pivot link between the mirror 17 and the guide rail 18. This allows the mirror 17 to change orientation by moving along the guide rail 18. This change in orientation can also be obtained by replacing the mirror 17 on the guide rail 18 with a mirror having the desired orientation.

[0079] The orientation of the mirror 17 allows the laser beam emitted by the dimensional sensor to be directed according to a desired orientation. In other words, the adjustment of the orientation of the dimensional sensors 3, 4 in the embodiment shown in Figure 1 is replaced here by adjustment of the orientation of the mirror 17, and this orientation of the mirror 17 defines the optical measurement direction of the dimensional sensors 3, 4. Thus, depending on the respective orientations of the mirror 17 and the dimensional sensors 3, 4, it is possible to define an optical measurement direction that forms an angle between the first and second line of sight, for example an angle of 30° to 70°, preferably 40° to 60°.

[0080] In another embodiment, the orientation of the mirror 17 is fixed, for example at 45° to the longitudinal axis of the threaded element 6, but the orientation of the dimensional sensors 3, 4 can be modified to strike the mirror 17 at a different angle and therefore point to a corresponding line of sight. Furthermore, the mirror 17 can have different shapes, for example a flat, multi-faceted, curved, etc. mirror 17 to allow for different orientations of the line of sight. For example, it is possible to have two mirrors 17, one for each dimensional sensor 3, 4, or, in contrast, a single mirror 17 with a specific shape that allows for pointing the line of sight depending on the orientation of the dimensional sensor 3 or 4.

[0081] Similar to the embodiment shown in FIG. 1, the calibration gauge 5 is positioned on the measurement path of the dimensional sensors 3, 4, which measurement path is defined by the mirror 17 so as to allow calibration with each measurement operation on the threaded element 6.

Claims

1. A dimension measuring device for a threaded element (1), said device comprising a framework (2) and a first laser line sensor (3) having a first optical measurement direction and a second laser line sensor (4) having a second optical measurement direction, said second optical measurement direction forming a non-zero angle A with said first optical measurement direction in a plane containing said first optical measurement direction, said first laser line sensor (3) and said second laser line sensor (4) being movably mounted on said framework (2) and having at least one measurement path allowing acquisition of geometric data of said threaded element (1), said path passing through a calibration gauge (5) and being able to pass through a portion of said threaded element (1), said device measuring said first laser line sensor (3) along a major axis (x) a framework (2) comprising an encoder arranged to determine a position of the first laser line sensor (3) and a position of the second laser line sensor (4); and an electronic unit arranged to construct a first part profile from the first laser line sensor (3) and a second part profile from the second laser line sensor (4), the electronic unit being arranged to construct a complete profile from the first part profile and the second part profile in dependence on the respective positions of the first laser line sensor (3) and the second laser line sensor (4) and in dependence on at least one measurement performed on the calibration gauge (5).

2. 2. The measuring device according to claim 1, wherein the angle A is between 30° and 70°, preferably between 40° and 60°.

3. 3. The measuring device according to claim 1, wherein the first laser line sensor (3) and the laser line sensor (4) are translationally mounted on the framework (2).

4. A measuring device according to any one of claims 1 to 3, wherein the calibration gauge (5) comprises a surface defining a predetermined reference length.

5. 5. Measuring device according to any one of claims 1 to 4, wherein the calibration gauge (5) comprises a support surface (52) arranged to contact the end face of the threaded element (6) to be measured.

6. 6. Measuring device according to any one of claims 1 to 5, comprising a positioning wedge (8) arranged so as to be able to support the threads of the threaded element (6).

7. 7. The measuring device according to claim 6, wherein the positioning wedge (8) comprises a tapered stabbing surface (9) having a tapered stabbing surface axis capable of contacting the threads of the threaded element (6).

8. 8. Measuring device according to claim 5 in combination with claim 6 or 7, wherein the support surface is perpendicular to the axis of the tapered insertion surface 9 of the positioning wedge 8.

9. 9. The measuring device according to claim 1, wherein the calibration gauge (5) comprises a piercing flank reference surface (54), a load flank reference surface (55), an axial length reference surface (56), and a radial length reference surface (57).

10. 10. The measuring device according to claim 1, wherein the calibration gauge (5) comprises a longitudinal reference extension (11) defining a reference length (Dr), and wherein the electronic unit is arranged to determine a measurement path correction factor associated with the paths of the first and second laser line sensors (3, 4).

11. 11. The measuring device according to any one of claims 1 to 10, wherein the electronic unit is arranged to compare a digital thread profile including a minimum dimension and a maximum dimension with the complete profile, the electronic unit being configured to generate a result of the compatibility of the thread.

12. Measuring device according to any one of the preceding claims, wherein the electronic unit is arranged to perform dimensional measurements of the surface of the end of the threaded element (1).

13. A method for said dimensional measurement of the end of a threaded element 1, comprising: attaching a measuring device according to any one of claims 1 to 12 to the threaded element 1; performing data acquisition by the first laser line sensor 3 and the second laser line sensor 4 on the measuring gauge 5; determining measurement correction factors and storing the measurement correction factors in a memory of the electronic unit; performing a second acquisition of data of the end of the threaded element 1 by the first laser line sensor 3 and the second laser line sensor 4; generating a first partial profile from a first data set resulting from a second acquisition of said data by said first laser line sensor 3; generating a second partial profile from a second data set resulting from a second acquisition of said data by said second laser line sensor 4; generating a complete profile from the first partial profile, the second partial profile and the measurement correction factors.

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