Tensile force measuring device

Abstract

Tensile force measuring device (1) for detecting the tensile force acting on a long item, with a base body (2) comprising - a first outer support unit (3) with a first guide element (7) adjustable between a release position releasing the long goods and a locking position fixing the long goods in a measuring position, - a second outer support unit (4) with a second guide element (8) which can be brought into contact with the long goods, - a deflection device (5) arranged between the first and second support unit (3, 4) with a deflection element (9) for partially wrapping the long material in the measuring position and - a force measuring unit connected to the deflection device (5) for detecting and displaying a first force resulting from the partial wrap on the deflection element (9), characterized in that for detecting and / or displaying a second force resulting from the partial wrap by the force measuring unit on the base body (2) at a distance from the first support unit (3) an additional support unit (10) with a contact element (11) is arranged, which is adjustable between a measuring position fixing the long item in its position on the additional support unit (10) in the measuring position of the first guide element (7) and a disengaged position spaced from the long item.

Description

[0001] The invention relates to a tensile force measuring device for detecting the tensile force acting on a long product, with a base body, comprising - a first outer support unit with a first guide element adjustable between a release position releasing the long goods and a locking position fixing the long goods in a measuring position, - a second outer support unit with a second guide element that can be brought into contact with the long goods, - a deflection device arranged between the first and second support unit with a deflection element for partially wrapping the long material in the measuring position and - a force measuring unit connected to the deflection device for recording and displaying a force resulting from the partial wrap acting on the deflection element.

[0002] Tensile force measuring devices of the type mentioned above are known in a wide variety of designs from the prior art. They are used to determine the tensile force acting on a long item, such as ropes, strands, wires, or the like, in open or closed force systems in which a long item that is flexible in the unloaded state is subjected to tensile force. The design of the tensile force measuring device allows for its use as needed at suitable locations on the long item subjected to tensile force. Typical applications for tensile force measuring devices include the tensile force measurement of guy wires on buildings, of ropes in conveyor systems such as elevators, and of guy wires on antenna masts.

[0003] A prior art tensile force measuring device is offered, for example, by the applicant under the name "CableBull," the dimensions of which can be found at https: / / honigmann.com / bilder / download / 105559 Dimensions.PDF. DE 100 16 254 A1 also relates to a tensile force measuring device referred to as a tensile force sensor for detecting the tensile force of a continuous material guided over a first support roller and a measuring roller arranged downstream of it, as well as over a second support roller arranged downstream of the measuring roller. For measuring the force acting on a cable, a handheld measuring device is known from DE 10 2009 028 521 A1, in which a force measuring device is mounted between a first and a second cable support element.DE 10 2015 007 995 A1 discloses both a tensile measuring device for determining a tensile load on at least one stationary or at least one moving support or tensile body, as well as a method for performing a corresponding measurement. A mobile tensile stress measuring device for detecting the tensile force of an endless material, such as a rope, band, wire, textile fiber, or the like, partially wrapping around two outer support rollers and a measuring roller arranged between the support rollers is disclosed in DE 10 2016 106 076 A1. Furthermore, DE 20 2004 020 950 U1 discloses a device for determining the tensile force in tensioned traction means, in particular ropes in elevators, with at least one device for deflecting the traction means, with which the traction means is deflected by a distance from a tensile axis and the reaction force to the deflection is measured.

[0004] The basic principle of known tensile force measuring devices is based on the deflection of the long item to be measured at the deflection device, which for this purpose is partially wrapped around by the long item in the measuring position. The partial wrapping is brought about by the first and second outer support units, wherein the second guide element of the second outer support unit and the first guide element of the first outer support unit are arranged in the locking position such that they bring about partial wrapping of the deflection element of the deflection device arranged between the first outer support unit and the second outer support unit. The force measuring unit connected to the deflection device is suitable for determining the force resulting from the partial wrapping, acting perpendicular to the direction of the tensile force, so that the tensile forces acting on the long item can be determined using these measured values.A constant wrap angle of the deflection element for each measurement is essential for a correct measurement result and its comparability.

[0005] For long goods that are flexible in the unloaded state, such as ropes, wires, belts, or the like, the force determined by the force measuring unit from the partial wrap around the deflection element essentially results solely from the tensile force acting on the corresponding long goods. For essentially inflexible long goods, such as rods, struts, or the like, the deflection of the long goods at the deflection device generated during measurement by the tensile force measuring device also causes a flexurally elastic deformation of the long goods, which leads to additional transverse forces on the force measuring unit and which are added to the force resulting from the tensile force. The force resulting from the force measuring unit during deflection is therefore made up of the tensile force acting on the long goods and the flexurally elastic deformation of the long goods generated during deflection.Without knowledge of the relationship between the two force components, the determined resulting force does not allow any direct conclusions to be drawn about the tensile force acting on the long goods.

[0006] The systems known from the state of the art therefore only allow a reliable determination of the tensile force acting on the long material if, as a result of the deflection of the long material caused during the measurement, the long material experiences no or only an insignificant flexural elastic deformation during the deflection.

[0007] Based on this, the object of the invention is to provide a tensile force measuring device that is universally suitable for measuring the tensile force acting on long goods.

[0008] The invention solves the problem by a tensile force measuring device having the features of claim 1. Advantageous developments of the invention are specified in the dependent claims.

[0009] A characteristic of the tensile force measuring device according to the invention is that, for detecting and / or displaying a second force resulting from the partial wrap, an additional support unit with a contact element is arranged on the base body at a distance from the first support unit, preferably in the area between the first support unit and the deflection device, in order to detect and / or display a second force resulting from the partial wrap by the force measuring unit, which additional support unit is arranged with a contact element which is adjustable between a measuring position fixing the long item in its position on the additional support unit in the measuring position of the first guide element and a disengaged position spaced from the long item.

[0010] In order to detect the tensile force acting on a long item by means of the tensile force measuring device according to the invention, the device is arranged on the long item to be measured in such a way that the long item extends along the base body between the outer support units and the deflection device, so that the two guide elements are arranged on the one hand of the long item and the deflection element is arranged in the area between the guide elements on the other hand of the long item.

[0011] After a corresponding positioning of the tensile force measuring device on the long material, the guide element on the first support unit is adjusted from its release position to the locking position, whereby the long material is transferred into a measuring position in which it partially wraps around the deflection element with a wrap angle, with a geometric deviation from a straight line within its linear flexural elastic range, so that the force measuring unit connected to the deflection element determines a first force resulting from the partial wrap of the long material threaded into the tensile force measuring device.

[0012] For a long item that undergoes flexurally elastic deformation in the threaded measuring position on the tensile force measuring device, the resulting force determined by the force measuring unit results from the tensile force acting on the long item and the flexurally elastic deformation of the long item. The tensile force-related component of the resulting force is determined using the additional support unit of the tensile force measuring device according to the invention in the manner described below.

[0013] While maintaining the measuring position of the long item on the tensile force measuring device that existed when the first resultant force was determined, i.e. while maintaining the locking position of the first guide element of the first outer support unit, the contact element of the additional support unit that is arranged in a disengaged position when the first resultant force is detected is moved from the disengaged position into a measuring position in which it rests on the long item in such a way that after a subsequent displacement of the first guide element from the locking position into the release position, it maintains the previously set measuring position while maintaining the wrap angle that existed when the first resultant force was determined.In this way, the lever arm extending between the deflection device and the first outer support unit is replaced by the lever arm extending between the deflection device and the additional support unit. In this setting of the tensile force measuring device, a second resultant force is measured by the force measuring unit, which differs from the first measured resultant force due to the changed lever arm.

[0014] The two resulting forces displayed on the force measuring unit's display allow the operator to determine the actual tensile force acting on the long material based on the two measured values. This is achieved using predetermined characteristic maps that contain a large number of data sets, the values ​​of which preferably include the determined first and second resulting forces as well as their difference. The predetermined characteristic maps have characteristic curves that allow a tensile force to be derived from the determined resulting forces. In addition, the flexural rigidity of the long material can preferably also be determined.

[0015] Based on the characteristic curve fields and the two determined resultant forces, the desired tensile force of the long material under test can thus be reliably determined. A characteristic curve field can, for example, be stored as a table with the previously recorded values, whereby it can be expediently provided that intermediate values ​​are determined by interpolation based on the previously determined values. The number of predetermined values ​​for representing the characteristic curve field is preferably selected to be sufficiently high that the intermediate values ​​determined by interpolation reliably define an accurate characteristic curve field, which makes it possible to determine the actual tensile force acting on the measured long material.

[0016] Particularly preferably, the predetermined characteristic curve array comprises enough data sets to cover all tensile forces measurable when using the respective tensile force measuring device. Furthermore, the data sets can cover such a wide range of flexural rigidity that all possible tensile force values ​​and flexural rigidity values ​​are covered for all possible long goods to be measured.

[0017] Knowing the first and second resulting forces and preferably a difference formed between them, the user does not have to make any further inputs, but can read the desired tractive force directly from the characteristic maps after recording the first and second resulting forces.

[0018] The tensile force measuring device according to the invention thus conveniently allows the tensile force acting on a long item, which also undergoes flexurally elastic deformation during the measurement. Thus, the tensile force measuring device according to the invention has a particularly broad range of applications, which is not limited to flexible long items, i.e., items that are not flexurally elastically deformed in the measuring position. The tensile force acting on the long item is determined using simple characteristic maps, which are created based on the determined first and second resultant forces and their relationship to one another, in particular their differential value.

[0019] Essential to the function of the tensile force measuring device according to the invention is that the long material is secured in the measuring position by means of the contact element of the additional support unit before the first guide element is displaced from the locking position, which secures the long material in the measuring position, to the release position, in order to maintain the existing wrap angle of the deflection element in the measuring position. The wrap angle is preferably <5°, particularly preferably <2°, and preferably <1.5°.

[0020] The contact element of the additional support unit can be adjusted between the measuring position and the disengaged position in any way, for example by pivoting the contact element onto the additional support unit. However, according to a particularly advantageous embodiment of the invention, the contact element is adjustable on the additional support unit transversely to the longitudinal axis of the long item threaded into the tensile force measuring device. According to this embodiment of the invention, the contact element is adjusted essentially perpendicular to the longitudinal axis of the long item in order to adjust it between the disengaged position and the measuring position. This embodiment of the invention enables particularly precise positioning of the contact element and its fixing in the measuring position in order to ensure that the measuring position of the long item is maintained with a constant wrap angle.

[0021] According to a particularly advantageous embodiment of the invention, the additional support unit has a screw mechanism for displacing the contact element between the disengaged position and the measuring position. The design of the screw mechanism, in particular the selection of the thread parameters, enables reliable and positionally secure adjustment of the contact element, while simultaneously securing the set measuring position via the screw mechanism, e.g., due to a self-locking thread. This embodiment of the invention thus ensures, in a particularly reliable manner, that the wrap angle of the deflection element by the long material is maintained when detecting the first resultant force and the second resultant force.

[0022] According to a further embodiment of the invention, it is further provided that the force acting on the long material by the contact element in the measuring position is adjustable. This embodiment of the invention allows the contact pressure of the contact element acting on the long material in the measuring position to be set. The adjustable force acting on the long material by the contact element ensures that the wrap angle of the deflection element is maintained particularly precisely when the second resulting force is detected. If a screw mechanism is used, a torque can be set to adjust the force acting on the long material, for example, which corresponds to the desired contact pressure of the contact element on the long material.

[0023] The adjustability of the first support unit can be configured so that the first guide element can be displaced between the release position, in which the long item can be threaded into the tensile force measuring device, and the locking position, in which the first resulting force is determined. For example, a linear adjustability of the first guide element can be provided, in which it can be adjusted essentially perpendicular to the longitudinal axis of the long item between the release position and the locking position. According to a particularly advantageous embodiment of the invention, however, the first support unit is designed such that the guide element can be pivoted between the release position and the locking position.This embodiment of the invention enables particularly convenient securing of the long material in the measuring position, with a defined pivoting capability enabling reliable locking of the locking position. According to an advantageous further development of the invention, particularly reliable securing of the first guide element in the locking position can be achieved by arranging the guide element in the locking position in an over-center position relative to the release position, thereby effectively preventing an unintentional relocation of the guide element from the locking position to the release position.

[0024] According to a further development of the invention, it is further provided that the first support unit, the second support unit and / or the deflection device are designed to adapt the first guide element, the second guide element and / or the deflection element to the cross-section of the long material. According to this embodiment of the invention, the guide elements and the deflection element are, for example, arranged interchangeably on the support units or the deflection device and can thus be adapted to the geometry of the long material to be measured, whereby this includes both the shape of the long material resulting from the cross-section and its diameter. Thus, the first guide element, the second guide element and / or the deflection element can be designed as runners, rollers, cylinders or rods in order to ensure optimal adaptation to the long material to be measured.Furthermore, it is also possible to adapt the first guide element, the second guide element or the deflection element to the diameter of the long material to be measured, which preferably has a circular cross-section, by means of an advantageously provided diameter adjustment.

[0025] When carrying out repeated measurements on a long item at intervals from one another, it is necessary for the comparability of the measurement results that the alignment of the tensile force measuring device on the long item is consistent for each measurement to be carried out, since due to the influence of gravity on the long item when the positioning of the tensile force measuring device or its alignment relative to the long item changes, the comparability of the measurement results may no longer be possible.

[0026] According to an advantageous embodiment of the invention, a position sensor is arranged on the base body to determine the spatial orientation of the base body when recording the resulting forces. This embodiment of the invention makes it possible to record comparable results, particularly with repeated measurements, which allow conclusions to be drawn about potentially changing tensile forces acting on the long goods. Particularly advantageously, in addition to a position sensor, a GPS sensor can also be provided, which makes it possible to reliably assign the measurements taken to the long goods being measured. A corresponding GPS unit can, for example, be arranged directly on the base body and connected to the force measuring unit.

[0027] According to an advantageous development of the invention, the force measuring unit is connected to an evaluation unit designed to determine and output the tensile force acting on the long material on the basis of the first and second resultant forces. According to this embodiment of the invention, the evaluation unit is designed to automatically determine the tensile force acting on the long material on the basis of the first and second resultant forces and to output this to the user, wherein the output can be visual and / or acoustic. This embodiment further increases the ease of use of the tensile force measuring device by eliminating the need for the operator to manually determine the tensile force acting on the long material on the basis of the first and second resultant forces. For this purpose, the evaluation unit accesses the predetermined characteristic maps.The determined tensile force acting on the long goods can be output via a visual display, e.g. a display, and / or via an acoustic output via a suitable loudspeaker unit.

[0028] The evaluation unit can be arranged directly on the base body. However, according to an alternative embodiment of the invention, the evaluation unit is wirelessly connected to the force measuring unit. A wireless connection, whereby the connection between the evaluation unit and the force measuring unit is established, for example, via Bluetooth, Wi-Fi, or the like, also enables central data acquisition of the measurement performed with the tensile force measuring device. The evaluation unit can be integrated, for example, into a laptop, tablet, or the like.

[0029] Particularly advantageously, it is provided that the evaluation unit is connected for data transmission to a storage unit in which the characteristic maps for determining the tensile force acting on the long material on the basis of the first and second resultant force are stored and / or which are designed to document the measuring processes. The use of a storage unit makes it possible to provide it with suitable characteristic maps which are used to determine the tensile force acting on the long material on the basis of the first and second resultant force. The use of a storage unit also makes it possible to update and supplement the evaluation unit with further characteristic maps, which enable a broader field of application of the tensile force measuring device. In addition, the use of a storage unit enables the measuring processes to be documented so that they can be reliably stored and retrieved.The storage unit can be connected to the evaluation unit either wirelessly or via appropriate cables.

[0030] According to a particularly advantageous embodiment of the invention, the evaluation unit is integrated into a mobile handheld device with a display unit for visual representation. The use of a mobile handheld device enables particularly flexible and simple use of the tensile force measuring device as well as the recording of the tensile force acting on the long goods and its documentation. According to a particularly advantageous embodiment of the invention, the mobile handheld device is formed by a mobile phone, with the evaluation unit and the storage unit being represented by a suitable application running on the mobile phone.

[0031] Additionally or alternatively, according to a further advantageous embodiment of the invention, the base body can have a display unit connected to the evaluation unit. This embodiment of the invention makes it possible, for example, to specify the measuring process sequence to the operator via the display unit and / or to indicate the completion of a measuring process, so that the operator can then end the measuring process and begin another measuring process on a different long item to be measured. The display unit can be designed, for example, as an LED display, which allows the operator to particularly conveniently record the progress of the measuring process, in particular its completion.

[0032] According to a further advantageous embodiment of the invention, it is further provided that the evaluation unit is connected to an acoustic output unit. An acoustic output unit enables the operator to indicate the status and progress of the measurement process, in particular its completion, or the like, via voice output and / or signal tones.

[0033] Particularly preferably, the tensile force measuring device is designed as a mobile tensile force measuring device, which allows it to be used universally.

[0034] An embodiment of the invention is explained below with reference to the drawing. In the drawings: Fig. 1 a front view of an embodiment of a mobile tensile force measuring device.

[0035] Fig. 1 shows an embodiment of a mobile tensile force measuring device 1 with a base body 2, on which a first support unit 3 and a second support unit 4 are arranged at a distance from one another on the outside. Centrally between the first support unit 3 and the second support unit 4, a deflection device 5 is arranged on the base body 2, which is connected to a force measuring unit (not shown here). The arrangement of the first and second support units 3, 4 and the deflection device 5 on the base body 2 is selected such that a long item to be measured (not shown here) is arranged in its measuring position on the tensile force measuring device 1 such that the long item - based on the illustration in Fig. 1 - in the threaded state is guided under the first and second support units 3, 4 and over the deflection device 5.

[0036] The first support unit 3 has a first rotatable guide element 7, which is mounted on a bearing disc 19 rotatably arranged in an opening 20 of the base body 2 between the Fig. 1 and a release position not shown here. The second support unit 4 has a second, rotatably mounted, second guide element 8 arranged on the base body 2. In the area of ​​the deflection device 5, a deflection element 9 serves to receive the long material. The deflection element 9 is connected to the force measuring unit (not shown here) in such a way that the resulting forces acting on the long material in the measuring position can be determined by a partial wrap of the deflection element 9.

[0037] The arrangement and removal of a long item to be measured on the tensile force measuring device 1 takes place in the release position of the first guide element 7 of the first support unit 3 (not shown here). In this position of the first guide element 7, the long item can be threaded without stress in the manner described above into the area between the first support unit 3, the second support unit 4 and the deflection device 5. After the arrangement of the long item, the first guide element 7 is moved into the Fig. 1, whereby for this purpose the first guide element 7 is moved relative to the base body 2 within the opening 20 into the position shown in Fig. 1 shown locking position, in which it is in an over-dead center position compared to the release position.

[0038] In the locking position of the first guide element 7, this and the second guide element 8 are arranged relative to the long material in such a way that a partial wrap with a wrap angle of preferably <5° exists on the deflection element 9. The deflection element 9 is connected to the force measuring unit in such a way that forces acting on the deflection element 9 from the partial wrap are recorded. These forces can be displayed on a display 21 of an evaluation unit 12, which is connected to the force measuring unit.

[0039] To reliably determine the tensile force acting on the long material, which undergoes flexurally elastic deformation during partial wrapping in the measuring position, the tensile force measuring device 1 has an additional support unit 10 in the area between the first support unit 3 and the deflection device 5. This is formed by a carrier 13 arranged on the base body 2, to which a feed device 14 connected to a contact element 11 is releasably secured via a lever 15. Using a rotary knob 16 of the additional support unit 10, the contact element 11 can be adjusted essentially perpendicularly to a long material arranged on the tensile force measuring device 1.

[0040] After a first resultant force has been detected, at which the measuring position is effected by the first and second support units 24, the contact element 11 is adjusted via a rotary knob 16 into a position in which the contact element 11 is arranged on the long material in such a way that, after a subsequent displacement of the first guide element 7 from the locking position to the release position, the long material remains in its previously set measuring position, in which the partial wrap angle is maintained. In the measuring position of the long material then effected by the additional support unit 10 and the second support unit 4, a second resultant force is detected, which deviates from the first resultant force due to a changed lever arm as a result of the different distances between the contact element 11 and the first guide element 7 and the deflection element 9.

[0041] In the evaluation unit 12, the actual tensile force acting on the long material is determined by taking into account the first resulting force, the second resulting force, and their relationship to one another, in particular their difference, and comparing it with previously stored characteristic maps. Furthermore, the measurement process is documented via a memory unit (not shown here) of the evaluation unit 12.

[0042] A handle 18 connected to the base body 2 serves not only to make the tensile force measuring device 1 easier to handle, but also to accommodate a position sensor (not shown here), by means of which the spatial position of the tensile force measuring device 1, i.e. the orientation of the tensile force measuring device 1 relative to all three spatial axes, can be recorded. Knowledge of the position of the tensile force measuring device 1 makes it possible to carry out gravity compensation of the determined measured values, i.e. the first and second resultant force. Gravity compensation enables particularly precise recording of the tensile forces acting on the long material, since the measured values ​​are influenced by the orientation of the tensile force measuring device 1 during the measuring process. The reason for this is the influence of gravity, which can, however, be compensated for by the position sensor, so that a measurement result adjusted for the influence of gravity can be displayed. The position sensor is, for example,coupled to the evaluation unit 12 in such a way that the data determined by the position sensor is automatically processed therein. The measurement data determined by the position sensor are thus electronically corrected for the influence of gravity.

Claims

[1] Tensile force measuring device (1) for detecting the tensile force acting on a long product, with a base body (2) comprising - a first outer support unit (3) with a first guide element (7) adjustable between a release position releasing the long goods and a locking position fixing the long goods in a measuring position, - a second outer support unit (4) with a second guide element (8) which can be brought into contact with the long goods, - a deflection device (5) arranged between the first and second support unit (3, 4) with a deflection element (9) for partially wrapping the long material in the measuring position and - a force measuring unit connected to the deflection device (5) for detecting and displaying a first force resulting from the partial wrap on the deflection element (9), characterized byin that, for detecting and / or displaying a second force resulting from the partial wrap by the force measuring unit, an additional support unit (10) with a contact element (11) is arranged on the base body (2) at a distance from the first support unit (3), which contact element is adjustable between a measuring position fixing the long item in its position on the additional support unit (10) in the measuring position of the first guide element (7) and a disengaged position spaced from the long item. [2] Tensile force measuring device according to claim 1, characterized by that the contact element (11) is arranged on the additional support unit (10) so as to be adjustable transversely to the longitudinal axis of the long material. [3] Tensile force measuring device according to claim 1 or 2, characterized by that the additional support unit (10) has a screw mechanism for displacing the contact element (11) between the disengaged position and the measuring position. [4] Tensile force measuring device according to one or more of the preceding claims, characterized by that the force acting on the long material by the contact element (11) in the measuring position is adjustable. [5] Tensile force measuring device according to one or more of the preceding claims, characterized by that the first support unit (3) is designed such that the first guide element (7) can be pivoted between the release position and the locking position. [6] Tensile force measuring device according to one or more of the preceding claims, characterized by that the first guide element (7) is arranged in an over-dead-center position in the locking position relative to the release position. [7] Tensile force measuring device according to one or more of the preceding claims, characterized bythat the first support unit (3), the second support unit (4) and / or the deflection device (5) are designed to adapt the first guide element (7), the second guide element (8) and / or the deflection element (9) to the cross-section of the long material. [8] Tensile force measuring device according to one or more of the preceding claims, characterized by that a position sensor is arranged on the base body (2) for determining the spatial orientation of the base body (2) when detecting the resulting forces. [9] Tensile force measuring device according to one or more of the preceding claims, characterized by that the force measuring unit is connected to an evaluation unit (12) which is designed to determine and output the tensile force acting on the long material on the basis of the first and second resulting force. [10] Traction device according to one or more of the preceding claims, characterized bythat the evaluation unit (12) is wirelessly connected to the force measuring unit. [11] Traction device according to one or more of the preceding claims, characterized by that the evaluation unit (12) is connected to a storage unit for data transmission in which characteristic maps for determining the tensile force acting on the long material on the basis of the first and second resulting force are stored and / or which are designed to document the measuring processes. [12] Traction device according to one or more of the preceding claims, characterized by that the evaluation unit (12) is integrated into a mobile handheld device with a display unit for optical representation. [13] Traction device according to one or more of the preceding claims, characterized by that the base body (2) has a display unit connected to the evaluation unit (12). [14] Traction device according to one or more of the preceding claims, characterized bythat the evaluation unit (12) is connected to an acoustic output unit.

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