DUAL MEASURING FUNCTIONALITY MECHANICAL ARM FOR GEOMETRA INSTRUMENTED PULLEY
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- CENT DE ING Y DESARROLLO IND
- Filing Date
- 2022-03-30
- Publication Date
- 2026-05-19
AI Technical Summary
Current instrumented geometers lack dual measurement functionality, with mechanical arms either measuring distance or mechanical conditions independently, leading to inaccurate defect location due to limited odometers and exposure to pipe conditions, and lack of protection for sensors.
A mechanical arm with integrated wheels and microencoders at both ends, allowing dual measurement of distance and mechanical condition, protected within a compact and airtight mechanism, reducing mechanical play and enhancing measurement accuracy.
Enhances measurement accuracy by increasing the number of odometers, reducing measurement errors, and protecting sensors from pipe conditions, enabling reliable defect localization.
Smart Images
Figure MX434119B0 
Figure MX434119B1
Abstract
Description
DUAL MEASURING FUNCTIONALITY MECHANICAL ARM FOR GEOMETRIC INSTRUMENTED PIGGY TECHNICAL FIELD The present invention belongs to the field of non-destructive testing for the measurement and location of mechanical defects in pipelines that transport hydrocarbons and gas, particularly it refers to a dual-functionality measuring mechanical arm for a geometric instrumented pig which has a novel internal mechanism whose structural characteristics merge the operations of measuring distance and mechanical conditions, such as ovality, dents and cracks, and is also characterized by allowing the use of micro technologies for sensing these variables, since it provides protection of these from external agents during measurement, and also allows maintaining the orientation and distance of such technologies. BACKGROUND The instrumented geometric pig is a technology used in pipeline inspection, focused on determining the geometric configuration and integrity of pipes or ducts. It employs sensors to detect and measure deformations that could affect the integrity of the pipe or impede or hinder the passage of fluids or other objects. The instrumented geometric pig generally consists of a central body or capsule to which the instrumentation is attached. This instrumentation consists of a plurality of circular mechanical arms used to measure the geometry of the pipe profile and its integrity. Each end of the capsule is supported by a pair of discs or cups. The instrumented devil capsule is mainly composed of two groups of arms, those that are enabled as odometers and those that are enabled as wall sensing (probes), the latter, by means of a chain of links are connected to transducers, which measure the changes in position to dimension: ovality, dents and cracks that can be found during the inspection. Regarding the mechanical arms, these are placed in different sections of the capsule. When placed in the same capsule, the odometer arms are located at the rear of the capsule, behind the support cup, and the sensing arms are placed in the middle section between the support cups. When more than one capsule is used, the sensing arms are placed in one capsule (bcornn / zznz / e / Yi) and the odometer arms in the other. However, for those enabled as odometers, the number of odometers remains reduced to between two and four, except when placed in the same capsule, where the number is three. For those that allow distance measurement, these technologies incorporate an odometer, which is instrumented with an encoder to measure wheel displacement. These encoders are generally located on the side and at the top of the arm face.The technologies that allow for measuring the mechanical condition of the pipeline are characterized by the transducers being placed in sections within the capsule, away from the pivot points of the arms. This necessitates the use of a set of links to maintain interaction with the transducer. The problem with using more than one link is the mechanical play (backlash) that exists at the points of connection between them, which results in inaccurate defect sizing. According to the prior art analysis, no instrumented pigs incorporating mechanical arms capable of dual measurement—that is, measuring both distance and the mechanical condition of the pipe—have been identified. Existing mechanical arms are classified into two groups: those that measure distance and those that measure mechanical conditions such as ovality, dents, and cracks. These are located in different parts of the capsule, grouped by function, and sometimes in different capsules; distance measurement arms in one section and mechanical deformation arms in another. Generally, they are found in different capsules, as these inspection instruments consist of more than one capsule. Different numbers of transducers are used for each type of measurement, with the ratio for mechanical condition sensing being 1 to 6, and even higher for large-diameter pipes. This ratio can be even greater because the number of odometers is considered constant regardless of the pipe diameter. Although both measurements are important, distance measurement has become the most relevant because it relates the location of the defect to the length of the inspected pipe. Inaccurate measurement makes it impossible to locate defects. Therefore, the objective is to increase the efficiency of distance measurement by increasing the number of odometers, since current instruments use an average of 3 units, and a limited number of instruments, at most 4, are reported in the state of the art. The lack of dual-measuring mechanical arms stems from the need to address issues of space maximization, wiring of rotating elements, transducer placement, and cavity geometry. Furthermore, these components must allow the capsule to remain slim and compact, enabling it to pass through narrow sections of up to 35% of the nominal pipe diameter—a highly valued characteristic for this type of device. In the case of odometers, necessary for distance measurement, existing prior art odometers have the drawback of requiring more space, hindering the optimization of the limited space ideally occupied by the measuring capsule. Another characteristic of current odometer equipment is that, while it uses encoders to measure wheel displacement, these encoders are located to the side of the wheel, connected by a copier. This prevents the proposed integration concept from being applied to the wall-mounted probe arms due to the space required. Furthermore, the state of the art does not report any structural geometry that protects them from the harsh conditions present in the inspected pipes due to the fluid and its pressure. Regarding the technologies identified in the prior art, document CN207688864U refers to a device for commissioning prior to the detection of the pipe's internal diameter. In this device, the mechanical arms for the odometers, located in the middle body of the instrumented pig, are independent of the arms for sensing deformation. These arms lack wheels at the end in contact with the surface; therefore, each measurement requires the operation of a separate arm. To protect the sensors from fluid pressure, the rear conical cup of the instrumented pig is used to prevent fluid from passing through and to form a chamber with the front cup. WO9613699, for its part, refers to a pipeline inspection pig and a method for its use, which comprises a pair of odometers mounted on the lower end of the instrumented pig and uses probe arms without wheels at the surface contact end; these arms are independent of the odometers. This document mentions the use of rotational sensors mounted on the rotation axes of the probe arms, which do not have wheels at the surface contact end, but it does not improve the way in which they are attached or establish any protection for them against fluid and pressure. Documents CA2428551 and JP2004333149 refer to an apparatus for measuring the shape of pipes, comprising sensing arms with a wheel at the end in contact with the pipe surface that uses a mechanism to measure wall deformations, using a set of links that usually have play, it also comprises a pair of odometers in the central part, independent of the sensing arms, but does not comprise an improvement or difference with respect to the way in which the wheel is connected to the odometer, nor a special protection for the sensors. Document GB0414781 refers to a sensor finger module for a pipe inspection tool, which is attached to the body of the instrumented pig and pivots by means of leaf springs; at the end in contact with the surface, it does not use a wheel or odometers. On the other hand, document CN102435669 refers to a support wheel-type internal pipe detection device and system focused on inspection by means of magnetic flux, which has mechanical arms with wheels to function as odometers, which is connected to the encoder by means of the axes of both parts; it does not indicate or show that the odometer is protected by means of any casing to protect it from the fluid and the pressure. Finally, document W02009133404 refers to a method and apparatus for monitoring pipelines, which comprises equipment for inspection by means of magnetic flux that uses rigid arms pivoted by means of a laminar spring, as well as an arrangement of 3 or 4 odometers to measure the distance traveled and mentions that there could be 4 pieces, it does not specify that it includes special protection for the transducer to protect it from pressure and fluid. Prior art technologies present various problems that are resolved by the present invention. These problems relate specifically to the characteristics of the mechanical arms used for measuring distance and mechanical condition (soundness), as well as the mechanism by which these arms are equipped with the necessary components to perform these functions. Furthermore, these technologies incorporate independent components to carry out the aforementioned activities; that is, they include mechanical arms with odometers for measuring distance, and other arms that palpate the pipe surface to assess its internal condition. The optimized characteristics of the proposed invention allow these drawbacks to be overcome, making it a novel technical solution. Therefore, the characteristics and configuration of the proposed invention allow these problems to be solved by enabling the instrumentation of both ends of the mechanical arm. This requires a structure that allows the use of microtechnologies for sensing the distance traveled by the instrumented pig during field inspections, as well as for measuring the mechanical condition of the pipeline. To this end, a wheel is integrated into the free end of the mechanical arm and instrumented to function as an odometer. This allows the number of odometers to be increased to the same number as the number of sensing mechanical arms. In this way, the concept of redundancy in measuring the length of the pipeline is implemented, substantially reducing the measurement error and consequently increasing the accuracy of locating any defects that may have been detected.In addition, there is the benefit of eliminating parts, which reduces the weight of the device, thus aiding in handling. This proposed development of the geometric capsule, incorporating the proposed features, makes it a state-of-the-art option due to its superior reliability. This invention's primary application lies in the field of non-destructive testing of pipelines, specifically in measuring defects such as ovality, dents, and cracks, which are indicative of plastic deformation defects. TECHNICAL PROBLEM TO BE SOLVED The proposed invention solves a latent problem in the state of the art, which consists of making a reliable measurement of the length of the inspected pipe runs.The origin of this problem lies in the fact that currently available technological alternatives have a limited number of mechanical arms that function as odometers, typically two to three pieces. These are generally located at the rear of the instrumented surveyor pig, outside the support cups. This allows them to be affected by the dirtiness of the pipe wall even after cleaning. This increases the likelihood that these components will not function accurately, as the pipe's cleanliness and dirtiness are not always optimal. Furthermore, the rotational behavior of the capsule during navigation makes it very likely that the length measurement will not be accurate. One alternative to solve this problem is to take advantage of the fact that the capsules of instrumented surveying pigs have mechanical sensing arms to probe the pipe surface, which are generally attached to the central part of the capsule via a revolving joint. Taking advantage of this configuration, it is possible to incorporate a mechanism into each of these arms that allows for the adaptation and operation of a wheel that performs the functions of an odometer. One of the challenges of this proposal is that the odometer has limited space, so compact mechanisms and transducers are required to optimize inspection resolution.This results in a redundant system for measuring both the distance and the internal conditions of the pipe, improving its accuracy by increasing the number of mechanical arms that have the aforementioned dual functionality, according to the number of arms of the capsule. The alternative referred to must also focus on addressing the problem of connecting the mechanical arms and the transducer needed to measure the deformations of the pipe walls. Some of those reported in the state of the art use the connecting rod-crank-slider type mechanism, which transforms a rotational movement into a translational one, and others use complex mechanisms to capture the rotational movement of the arm to a rotary transducer, which requires mechanisms that comprise a plurality of links. However, this configuration presents a drawback due to play in the joint connections, which leads to errors in deformation measurement because the play in the joints absorbs some of the movement that the links should perform. Similarly, there are devices that use encoders to measure pipe deformation; these also employ a more complex set of links to transmit and maintain the rotational movement of the mechanical arm to the transducer, and therefore suffer from the same problem of mechanical play in the link connections. To contribute to the solution of this problem, the present invention comprises a rotary transducer directly connected to the arm shaft that quantifies the deformation measurement, eliminating extra links, thereby making it possible to record the minimum movement induced by defects or imperfections. This invention also incorporates a novel geometry for the arm and the mechanism for the arm body and the wheel, allowing the arms to have a dual measuring functionality, measuring the geometry of the pipe surface and measuring the distance traveled. OBJECT OF THE INVENTION bcornn / zznz / e / Yi An object of the present invention is to provide a dual-measuring mechanical arm for a surveying instrument pig, comprising a novel mechanism that increases the efficiency of measuring the distance traveled by the instrumented pig during field inspections, as well as measuring the mechanical condition of the pipeline. This mechanism allows the incorporation of a plurality of these independent mechanical arms, grouped in different sections of the surveying instrument pig, into the body of the surveying instrument pig. These arms possess technical characteristics that allow them to be fused into a single unit, giving the resulting element dual measurement capabilities.These mechanical arms are attached to the surface of the instrumented pig and allow the measurement of the mechanical condition of the pipe by means of its instrumentation at that end; at the other end the wheel and its instrumentation are placed for measuring the distance and enabling its operation as an odometer. The invention increases the efficiency of measuring the distance traveled by the capsule during field inspections, such as assessing the mechanical condition of pipelines. Currently, these measurements are performed using independent mechanical arms grouped in different sections of the capsule, and often in different capsules of the device. Analyzing the instrumentation and structure of these arms reveals characteristics that allow them to be fused into a single unit, giving the resulting element dual measurement capabilities; that is, the ability to measure both distance and mechanical condition simultaneously. Currently, both arms are instrumented at only one end, leaving the other end free. To enable the arms to function as odometers, the upper portion is used to mount the wheel and instrumentation, while the lower portion serves only as a clamping joint. The state of the art does not mention the use of any type of housing design to cover the instrumentation, so the instruments are left exposed to the elements and in contact with the fluid being transported in the pipes. This poses a problem for current microtechnologies of sensors and transducers, which are small, on the order of millimeters. Due to these dimensions, the signals generated by the sensors are weak, making it mandatory to design cavities that house them and keep them hermetically sealed and aligned to prevent signal loss.For the arms used to measure mechanical condition, the lower part is used to mount the instrumentation. However, like odometers, they lack special, hermetically sealed cavities to protect the instrumentation, which presents the same drawback mentioned earlier. The free end is used to feel the pipe wall and monitor its mechanical condition or physical state. Therefore, the present invention offers several advantages. First, it allows for the precise measurement of the pipe's geometry, thanks to the instrumentation integrated into the mechanical arm and its position, thus avoiding the use of connecting link chains that introduce significant measurement errors. The second advantage is ensuring an effective measurement of the distance traveled during inspection. This is achieved by instrumenting the wheel in contact with the pipe wall with a rotary sensing transducer. This feature is implemented on each of the mechanical arms, increasing the number of odometers, creating a redundant system, and ensuring reliable measurement. This translates into easy location and identification of defects during inspection. The third advantage of the invention is the number and placement of the odometers on the instrumented geometric pig. These odometers are positioned near the middle of the pig's body, which helps prevent misalignment with the pipe's generating line from affecting its operation and hindering the wheels' rotation. Finally, the fourth advantage lies in the configuration of the proposed invention, which allows for a reduction in its dimensions compared to other existing alternatives in the prior art. This reduction can reach up to 35% of the pipe's nominal diameter, and preferably, the instrumentation of the proposed invention is applicable to pipes with a nominal diameter of 6 inches and larger. This optimization also allows for a reduction in the weight of the instrumented geometric pig, improving its handling. BRIEF DESCRIPTION OF THE INVENTION The present invention consists of providing a dual-function measuring mechanical arm for a surveying instrumented pig, which comprises a novel mechanism that increases the efficiency of measuring the distance traveled by the instrumented pig during field inspections, as well as measuring the mechanical condition of the pipeline. This mechanical arm comprises: A rectangular figure comprising an internal mechanism that facilitates its instrumentation, allowing the articulation of the arm, as well as its attachment to the capsule of the instrumented geometric pig; this novel mechanism allows the mechanical arm of the present invention to perform dual measurements by providing it with greater freedom of movement, which increases the effectiveness of measuring the distance traveled by the instrumented pig, as well as measuring the mechanical condition of the pipe. bcornn / zznz / e / Yi A base for attaching the mechanical arm of the present invention to the instrumented geometer devil capsule, as well as for holding it in position, which in turn comprises a pair of clamps. A rigid central body of the mechanical arm that is joined at one end to the rectangular figure and at the other end to the other components of the mechanical arm of the present invention. A fork-shaped figure, which is attached to the other end of the central body of the mechanical arm and whose function is to keep the wheel in position. A wheel comprising an internal mechanism that facilitates its instrumentation, which in turn serves as an odometer for measuring the distance traveled by the instrumented geometric pig; this novel mechanism allows the mechanical arm of the present invention to perform dual measurements by providing it with greater freedom of movement, which increases the effectiveness of measuring the distance traveled by the instrumented pig, as well as measuring the mechanical condition of the pipe. A module for the instrumentation of the mechanical arm of the present invention, particularly placed in the rectangular figure and on the wheel; this module comprises two microencoders, which may be of the optical or magnetic type, with preferred dimensions of 5mm in diameter and 10mm in length, in the case of the optical ones, and 12mm high, 8mm wide and 2.6mm thick, when they are of the magnetic type; the latter are complemented by a magnet whose preferred dimensions are 6mm in diameter by 2.5mm thick. BRIEF DESCRIPTION OF THE FIGURES The following describes specific methods to illustrate the present invention, in relation to the attached figures, which are included for illustrative purposes only and are not intended to limit the present invention. Figure 1 illustrates a perspective view of a preferred implementation of a plurality of mechanical arms of the present invention on a geometer instrumented devil. Figure 2 illustrates a side view of a preferred implementation of a plurality of mechanical arms of the present invention in a geometric instrumented pig within the pipe in straight and curved sections. bcornn / zznz / e / Yi Figure 3 illustrates a cross-sectional view of a preferred implementation of a plurality of mechanical arms of the present invention on a geometer instrumented devil. Figure 4 illustrates a perspective view of a preferred implementation of the mechanical arm of the present invention. Figure 5 illustrates a perspective view of a preferred implementation of the rectangular figure of the mechanical arm of the present invention. Figure 6 illustrates a cross-sectional view of a preferred implementation of the internal mechanism of the rectangular figure of the mechanical arm of the present invention. Figure 7 illustrates a perspective view of a preferred implementation of the cover for the rectangular figure mechanism and for the mechanical arm wheel of the present invention. Figure 8 illustrates a perspective view of a preferred implementation of the independent axis of the mechanical arm of the present invention. Figure 9 illustrates a perspective view of a preferred implementation of the mechanical arm wheel of the present invention. Figure 10 illustrates a cross-sectional view of a preferred implementation of the internal mechanism of the mechanical arm wheel of the present invention. Figure 11 illustrates a perspective view of a preferred implementation of the base for holding the mechanical arm of the present invention. Figure 12 illustrates a perspective view of a preferred implementation of the mechanical arm of the present invention. Figure 13 illustrates a front view of an implementation of a plurality of mechanical arms on a geometric instrumented pig inside a pipe, the alignment of the pipe's generatrix line coinciding with the longitudinal axis of the instrumented pig. Figure 14 illustrates a side view of an implementation of a plurality of mechanical arms on a geometric instrumented pig inside a pipe in position and orientation, the alignment of the generating line of the pipe has a deviation represented by the angle β with the longitudinal axis of the instrumented pig. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical arm comprising a novel mechanism at each end, which enables it to perform dual measurements. This allows for increased efficiency in measuring the distance traveled by the instrumented pig during pipeline inspections, as well as in measuring the mechanical condition of the pipeline. The configuration of this arm mechanism incorporates improvements and optimizations in the structure and operation of its components. Furthermore, it facilitates the implementation of multiple mechanical arms with the characteristics described in the instrumented pig's capsule, thus enabling more accurate results. The mechanical arm of the present invention comprises a rectangular prism with an internal mechanism that facilitates its instrumentation, which allows the articulation of the arm, as well as its attachment to a base that in turn attaches it to the capsule of the instrumented geometric devil and keeps it in position; a central body that is joined at one end to the rectangular prism and at the other end to a fork-shaped figure, whose function is to keep the wheel in position; said wheel serves as an odometer and comprises an internal mechanism that facilitates its instrumentation; an instrumentation module distributed in the rectangular prism and in the wheel, which comprises microencoders, which may be of the optical or magnetic type. A plurality of mechanical arms with the technical characteristics referred to above are attached to the capsule or central body of the instrumented geometer pig, which increases the effectiveness of measuring the distance traveled by the instrumented pig, as well as measuring the mechanical condition of the pipeline. Figure 1 illustrates a preferred implementation of the instrumented geometric pig, which consists of a central body or capsule (E). This capsule comprises a cylindrical structural element (e) to which the pig's instrumentation is attached. The instrumentation consists of a plurality of the mechanical arms (D) of the present invention, arranged circumferentially to measure the profile geometry and soundness of the pipe. Each end of the cylindrical structural element (e) of the capsule (E) is supported and attached to the faces of a pair of discs or cups (B). A locator or tracker (C) is attached to the outer face of one of the discs or cups (B). The tracker's function is to monitor the position of the instrumented pig within the pipe.Figure 2 illustrates an example of the instrumented pig's navigation during the inspection of a pipe's geometry, both straight (F) and curved (G). In both cases, the novel configuration of the mechanical arm and the attachment of a plurality of these arms to the cylindrical structural element (e) of the capsule (E) allows the arms to adapt to the pipe's surface, as well as enabling multiple sensing for greater accuracy. Figure 3 illustrates a cross-section of the instrumented geometry pig, showing a compartment for the cards (H), to which the instrumentation of the plurality of mechanical arms of the present invention (D) is connected by cables. bcornn / zznz / e / Yi Figures 4, 5, 6, 7, 8, and 12 illustrate an implementation of the rectangular prism and its internal mechanism, which facilitates its instrumentation and allows the articulation of the robotic arm. The rectangular prism comprises two main parts: a main rectangular structure (100) and a lid (300).Preferably, the main rectangular structure (100) is characterized in that it comprises a base (101) that closes one of its faces, from the center of which protrudes a hollow cylindrical protrusion (107); the other face of the main rectangular structure (100) has an edge with a series of threaded holes (106), as well as four concentric cavities of different diameters (102, 103, 104 and 105), the one with the largest diameter (104) being located in the first position, from the outside to the inside, while the one with the smallest diameter (105) coincides with the diameter of the hollow part of the cylindrical protrusion (107) and in this a permanent magnet (203) is housed which is the complement of a hall effect transducer, in those cases in which this type of microencoder is used. The lid (300) is rectangular in shape and has a hole (306) on its outer face that extends to its inner face. On its inner face, it has a cylindrical protrusion (301) of larger diameter. This cylindrical protrusion (301) has two concentric cavities (302 and 303), one (303) with a smaller diameter than the other (302). A groove (304) is located on the outer diameter of the cylindrical protrusion (301). The mechanism that allows the joining of both pieces of the orthohedral figure (100 and 300) and that in turn fulfills its technical function requires an independent or fixed axis (400), which is characterized by being made up of two cylinders, a cylindrical body (402) and a circular head (403), where the diameter of the latter is greater than that of the cylindrical body (402).Preferably, the cylindrical body (402) is characterized by having a machined groove (404) that serves to place a commercial retaining lock, whose function is to prevent axial movement of the independent shaft (400) since this movement is limited by the bearing (202) and the cylindrical pulley (201); the outer face of the circular head (403) has a rectangular cavity (406) that preferably houses an integrated circuit or hall effect transducer, the central part of the cavity (406) has a hole (405) that passes through the entire independent shaft (400), this hole (405) and the groove (401) are useful for guiding the cable of the instrumentation of the mechanical arm of the present invention. bcornn / zznz / e / Yi For the assembly of the rectangular figure and its internal mechanism (200), the independent shaft (400) is placed inside the main rectangular structure (100) so that the outer diameter of the circular head (403) and the diameter of the inner cavity (102) fit together. A bearing (202) is placed around the cylindrical body (402) so that its diameter is slightly smaller than the diameter of the cavity (103), ensuring a proper fit. Finally, the cover (300) is placed so that the cylindrical body (402) passes through the hole (306), leaving a portion exposed. The diameter of the first cavity (104) of the main rectangular figure (100) is slightly larger than the diameter of the cylindrical protrusion (301), so both pieces fit together perfectly. A mechanical seal (204) is preferably placed in the cavity (302). while in the cavity (303) is housed a cylindrical pulley (201) that allows the mechanical seal (204) to be held in position.A groove (304) is located on the outer diameter of the cylindrical protrusion (301), in which an O-ring seal is preferably placed. The diameters of the cavities in the main rectangular structure (100) and the cover (300) that hold the independent or fixed shaft (400) are sufficient to allow the cylindrical body (402) to rotate freely. The threaded holes (106) allow the cover (300) to be fixed to the main rectangular structure (100) of the orthohedral figure by means of mechanical fastening, to ensure the assembly of the components of the internal mechanism (200) of the orthohedral figure. Figures 11 and 12 illustrate a preferred implementation of the base for holding and maintaining the position of the mechanical arm at the end (200) of the present invention, which in turn comprises a main body (705). It is complemented by a pair of clamps (703 and 704) and a bushing (701).For its part, the attachment of the mechanical arm to the structural element (e) of the capsule (E) of the instrumented geometer pig is carried out by attaching the bushing (701) to the cylindrical protrusion (107) of the orthohedral figure; the clamp (704) is used to center this structure; meanwhile, the second clamp (703) is attached to the cylindrical body (402) of the independent or fixed shaft (400) that protrudes from the cover (300), preventing it from rotating; this technical feature allows achieving a novel objective not existing in the state of the art, which consists of the orthohedral figure rotating without damaging the cables of the instrumentation of the mechanical arm, which come out through the hole (405) of the independent shaft (400).To keep the end of the mechanical arm that houses the odometer always in contact with the pipe surface, a bcornn / zznz / e / Yi cylindrical shaft (706) is included which is screwed to the clamp (704) whose function is to hold a torsion spring (702) that applies the force necessary for contact. Figures 4 and 12 illustrate a preferred implementation of the rigid central body (800) of the mechanical arm, to which a rectangular prism is attached at one end and a fork-shaped figure at the other via mechanical clamping means. Preferably, the central body (800) is characterized in that both ends have a configuration that facilitates its instrumentation to allow dual measurement, functioning as an odometer and as a surface probe, thus providing greater efficiency in both measurements. The fork-shaped component is attached to the other end of the central body (800) of the mechanical arm and its function is to hold a wheel or odometer (500) in position. Preferably, it comprises a pair of clamps (606 and 607) and a hub (609), which are detachable to facilitate assembly with the wheel (500) and its internal mechanism. The pair of clamps (606 and 607) that hold the wheel (500) are characterized by being detachable, preferably by means of a threaded mechanism. The hub (609) is characterized by facilitating the centering of the wheel (500), and it is, in turn, held in position by the clamp (606). Figures 4, 9, 10, and 12 illustrate a preferred implementation of the wheel (500) and its internal mechanism, which functions as an odometer and is characterized by comprising a main wheel structure (500) and a cover (300). Preferably, the main wheel structure (500) is characterized by comprising a base (501) that closes one of its faces, from the center of which protrudes a hollow cylindrical protuberance (507). The other side of the main structure has an edge with a series of threaded holes (506), as well as four concentric cavities of different diameters (502, 503, 504 and 505), with the one of the largest diameter (504) in the first position, from the outside to the inside, while the one of smallest diameter (502) coincides with the diameter of the cylindrical protrusion (507) and in this is housed a permanent magnet (602) which is the complement of the hall effect transducer, in those cases where this type of microencoder is used. The lid (300) has the same characteristics as the one used in the rectangular figure, meaning it is rectangular in shape. Its outer face has a hole (306) that passes through it to its inner face. On its inner face, it has a cylindrical protrusion (301) of larger diameter. This cylindrical protrusion (301) has two concentric cavities (302 and 303), one (303) with a smaller diameter than the other (302). A groove (304) is located on the outer diameter of the cylindrical protrusion (301). The mechanism that allows the union of both parts of the internal mechanism of the wheel (500) and that in turn it fulfills its technical function requires an independent or fixed axle (400), it has the same characteristics as the one used at the end of the orthohedral figure, that is, it is characterized by being made up of two cylinders, a cylindrical body (402) and a circular head (403), where the diameter of the latter is greater than that of the cylindrical body (402).Preferably, the cylindrical body (402) is characterized by having a machined groove (404) that serves to place a commercial retaining lock, whose function is to prevent axial movement of the independent shaft (400) since this movement is limited by the bearing (608) and the cylindrical pulley (604); the outer face of the circular head (403) has a rectangular cavity (406) that preferably houses an integrated circuit or hall effect transducer, the central part of the cavity (406) has a hole (405) that passes through the entire independent shaft (400), this hole (405) and the groove (401) are useful for guiding the cable of the instrumentation of the mechanical arm of the present invention. For the assembly of the wheel (500) and its internal mechanism (600), the independent axle (400) is placed inside the main body of the wheel (500), so that the cylindrical head (403), with a slightly smaller diameter, fits into the diameter of the cavity (503). A bearing (608) is placed around the cylindrical body (402) so that its diameter is slightly smaller than the diameter of the cavity (505), ensuring a proper fit. Finally, the cover (300) is placed so that the cylindrical body (402) passes through the hole (306), leaving a portion exposed. The diameter of the first cavity (504) of the main body of the wheel (500) is slightly larger than the diameter of the cylindrical protrusion (301), so both pieces fit together perfectly. A mechanical seal (605) is preferably placed in the cavity (503). while in the cavity (505) is housed a cylindrical roller (604) that allows the mechanical seal (605) to be held in position.A groove (304) is located on the outer diameter of the cylindrical protrusion (301), in which an O-ring seal is preferably placed. The diameters of the cavities in the main body of the wheel (500) and the cover (300) that hold the independent or fixed axle (400) are sufficient to allow the cylindrical body (402) to rotate freely. The threaded holes (506) allow the cover (300) to be attached to the main body of the wheel (500) by means of mechanical fasteners, to ensure the assembly of the components of the internal mechanism of the wheel (600). bcornn / zznz / e / Yi The instrumentation module is located inside the rectangular prism (100) and the wheel (500). This module preferably comprises a measuring sensor and a mechanism located both inside the cavities of the rectangular prism and in the wheel (500). Preferably, the sensor is a microencoder of the type available in the prior art, more preferably a rotary Hall effect or optical sensor. To implement rotary microencoder sensors, the joints at both ends of the mechanical arm must be of the rotary type, i.e., they must rotate about an axis. Therefore, the novelty and inventive step of the proposed invention lies in the design of the cable routing system for the instrumentation cables, which are routed from inside the cavities of both the rectangular prism (100) and the wheel (500) without becoming entangled during operation. The preferred dimensions of the microencoders used for the instrumentation of the mechanical arm of the present invention are 5mm in diameter and 10mm in length, in the case of optical ones, and 12mm high, 8mm wide and 2.6mm thick, when they are of the magnetic type; the latter are complemented with a magnet whose preferred dimensions are 6mm in diameter by 2.5mm thick. By implementing multiple arms as odometers within the support cups, it can be ensured that the phenomenon of misalignment and rotation of the capsule within the pipe will not affect the measurement of the distance traveled by the instrumented pig within the pipe in which it is used. This condition is represented by Figures 13 and 14, where the misalignment is shown as the angle β between the generatrix line of the pipe (I) and the longitudinal axis (J) of the instrumented pig. The acceptable misalignment value β is up to 5°.
Claims
1. A dual-function measuring mechanical arm for an instrumented pig, comprising a central body or capsule (E), a cylindrical structural element (e) whose ends are attached to the faces of a pair of discs or cups (B), a locator or tracker (C) being attached to the outer face of one of the discs or cups (B); wherein said mechanical arm comprises: A rectangular figure comprising a main rectangular structure (100), a cover (300), an independent or fixed shaft (400) and an internal mechanism; A wheel or odometer comprising a main structure (500), a cover (300), an independent or fixed shaft (400) and an internal mechanism; A fork-shaped figure comprising a pair of clamps (606 and 607) and a bushing (609), which are detachable to facilitate assembly;A rigid central body (800) attached by mechanical fastening means, at one end to the rectangular figure and at the other end to the fork-shaped figure. A base for attaching the mechanical arm, which in turn comprises a main body (705), a pair of clamps (703 and 704), a bushing (701), a cylindrical shaft (706), and a torsion spring (702). A module for instrumenting the mechanical arm.
2. The mechanical arm referred to in claim 1, further characterized in that the main rectangular structure (100) of the orthohedral figure comprises a base (101) that closes one of its faces, from the center of which protrudes a hollow cylindrical protuberance (107), the other face of the main rectangular structure (100) has an edge with a series of threaded holes (106), as well as four concentric cavities of different diameters (102, 103, 104 and 105), the one with the largest diameter (104) being located in the first position, from the outside to the inside, while the one with the smallest diameter (105) coincides with the diameter of the hollow part of the cylindrical protuberance (107).
3. The mechanical arm referred to in claim 1, further characterized in that the cover (300) of the orthohedral figure is rectangular in shape and on its outer face has a hole (306) that passes through it to its inner face, which has a cylindrical protrusion (301) that has two concentric cavities (302 and 303) of smaller diameter, one (303) with respect to the other (302), in turn, the cylindrical protrusion (301) has a groove (304) on its outer diameter.
4. The mechanical arm referred to in claim 1, further characterized in that the independent or fixed axis (400) of the rectangular figure is comprised of a cylindrical body (402) and a circular head (403), wherein the diameter of the circular head (403) is greater than that of the cylindrical body (402) and the latter has a machined groove (404) for placing a retaining lock,In turn, the outer face of the circular head (403) has a cavity (406) and in the central part of this it has a hole (405) that passes through the entire independent shaft (400).
5. The mechanical arm referred to in claim 1, further characterized in that for the assembly of the internal mechanism of the orthohedral figure, the independent shaft (400) is first placed inside the main rectangular structure (100), a bearing (202) is placed around the cylindrical body (402) whose diameter fits into the cavity (103), subsequently the cover (300) is placed so that the cylindrical body (402) passes through the hole (306) leaving a part exposed and allowing it to rotate freely, because the diameter of the first cavity (104) of the main rectangular figure (100) is slightly larger than that of the cylindrical protrusion (301) both pieces fit together, a seal is placed in the groove (304) of the cylindrical protrusion (301),Preferably O-ring type, the union of these components forms a pair of cavities, in cavity (302) a mechanical seal (204) is placed, while in cavity (303) a cylindrical roller (201) is housed to keep the mechanical seal (204) in position, finally the threaded holes (106) allow fixing the cover (300) to the main rectangular structure (100) through mechanical fastening means to ensure the assembly of the components of the internal mechanism (200) of the orthohedral figure.
6. The mechanical arm referred to in claim 1, further characterized in that the main structure (500) of the wheel or odometer comprises a base (501) that closes one of its faces, from the center of which protrudes a hollow cylindrical protuberance (507), its other face having an edge with a series of threaded holes (506), as well as four concentric cavities of different diameters (502, 503,504 and 505), the one with the larger diameter (504) being in the first position, from the outside to the inside, while the one with the smaller diameter (502) coincides with the diameter of the cylindrical protuberance (507). 7.- The mechanical arm referred to in claim 1, further characterized in that the cover (300) of the wheel or odometer is rectangular in shape and on its outer face has a hole (306) that passes through it to its inner face, which has a cylindrical protuberance (301) that has two concentric cavities (302 and 303) of smaller diameter, one (303) with respect to the other (302), in turn, the cylindrical protuberance (301) has a groove (304) on its outer diameter.
8. The mechanical arm referred to in claim 1, further characterized in that the independent or fixed axle (400) of the wheel or odometer is comprised of a cylindrical body (402) and a circular head (403),wherein the diameter of the circular head (403) is greater than that of the cylindrical body (402) and the latter has a machined groove (404) for attaching a retaining clip, the outer face of the circular head (403) has a cavity (406) and in the center of this cavity has a hole (405) that passes through the entire independent shaft (400).
9. The mechanical arm referred to in claim 1, further characterized in that, for the assembly of the internal mechanism of the wheel or odometer, the independent shaft (400) is first placed inside the main body (500), so that the cylindrical head (403), with a slightly smaller diameter, fits with the diameter of the cavity (503), and a bearing (608) is placed around the cylindrical body (402) so that its diameter is slightly smaller than the diameter of the cavity (505), so that both fit together.The cover (300) is then placed so that the cylindrical body (402) passes through the hole (306), leaving a portion exposed and allowing it to rotate freely. Because the diameter of the first cavity (504) is slightly larger than the diameter of the cylindrical protrusion (301), both pieces fit together. A seal, preferably an O-ring, is placed in the groove (304) of the cylindrical protrusion (301). The union of these components forms a pair of cavities. A mechanical seal (605) is placed in cavity (503), while a cylindrical pulley (604) is housed in cavity (505) to hold the mechanical seal (605) in position. Finally, the threaded holes (506) allow the cover (300) to be fixed to the main body of the wheel (500) by means of mechanical fasteners, to ensure the assembly of the components of the internal mechanism of the wheel. (600). 10.- The mechanical arm referred to in claim 1,further characterized in that the fork-shaped hub (609) is placed on the cylindrical protrusion (507) of the wheel or odometer and centers and holds the wheel or odometer in position, while the pair of clamps (606 and 607) hold it, one clamp (606) holding the hub (609) and the second clamp (607) holding the cylindrical body (402) of the independent shaft (400).
11. The mechanical arm referred to in claim 1, further characterized in that the mechanical arm is attached to the structural element (e) of the capsule (E) by means of the attachment of the hub (701) to the cylindrical protrusion (107) of the rectangular figure. The clamp (704) is used to center this structure, while the second clamp (703) is attached to the cylindrical body (402) of the independent or fixed shaft (400) that protrudes from the cover (300), preventing it from rotating.
12. The mechanical arm referred to in claim 1,further characterized in that, to maintain the wheel or odometer in contact with the pipe surface, the cylindrical shaft (706) is screwed to the clamp (704) to hold the torsion spring (702) which applies the force necessary for contact.
13. The mechanical arm referred to in claim 1, further characterized in that the instrumentation module is placed in the internal mechanism of the rectangular and fork-shaped figure and comprises a measuring sensor, which may be of the magnetic or optical type, whose preferred dimensions are 5 mm in diameter and 10 mm in length, in the case of the optical type, and 12 mm high, 8 mm wide and 2.6 mm thick, in the case of the magnetic type.
14. The mechanical arm referred to in claim 13, further characterized in that the magnetic sensor is preferably of the rotary Hall effect type and has a magnet,The central body is placed in a cavity (406) on the outer face of the circular head (403) of the independent shaft (400), while the magnet is placed in one of the cavities of the rectangular and fork-shaped figures 10 (203 and 602), while the cable of said sensor is extracted through the hole (405) of said shaft (400). 15.- The mechanical arm referred to in claim 13, further characterized in that the preferred dimensions of the measuring sensors are 5 mm in diameter and 10 mm in length, in the case of the optical sensors, and 12 mm in height, 8 mm in width and 2.6 mm in thickness, in the case of the magnetic type; 15 these latter sensors are complemented by a magnet whose preferred dimensions are 6 mm in diameter by 2.5 mm in thickness.