Abstract
A method for producing a force-measuring element (10) having at least one articulation point (20) which separates one region of the force-measuring element (10) into two connected subregions (11, 12) which can be deflected in relation to one another. The method includes: providing a force-measuring element blank (10), removing material from the force-measuring element blank (10) in order to produce the articulation point (20), checking whether the deflection behavior of the subregions (11, 12) which is produced by the articulation point corresponds to a predefined specification, defining a correction form (30) which can be produced through material removal and compensates for an ascertained deviation from the predefined specification, correcting the articulation point geometry using a laser and the previously defined correction form (30), through material removal at the articulation point.
Claims
1. A method for producing a force-measuring element having at least one articulation site which separates a region of the force-measuring element into two connected sub-regions which deflect relative to one another, comprising: a) providing a force-measuring element blank, b) removing material from the force-measuring element blank to produce the articulation site having an actual articulation site geometry, c) testing whether a deflection behavior of the sub-regions through the articulation site corresponds to a predetermined accuracy class specification or deviates therefrom, wherein c1) if the deflection behavior corresponds to the predetermined specification, ending the method, and c2) if the deflection behavior deviates from the predetermined specification, executing step d, d) testing whether the deviation is compensatable with an articulation site correction, wherein d1) if the deviation is compensatable, executing steps e through g, and d2) if the deviation is not compensatable, executing step h, e) determining a correction form producible through material removal, which compensates for the deviation from the predetermined specification, f) correcting the articulation site geometry in accordance with the determined correction form, through material removal with a laser, g) again executing the step c, h) testing whether the deflection behavior corresponds to a lower accuracy class specification or deviates therefrom, wherein h1) if the deflection behavior corresponds to the lower specification, classifying the force-measuring element in the lower accuracy class and ending the method, and h2) if the deflection behavior deviates from the lower specification, classifying the force-measuring element as a defective product and ending the method.
2. The method according to claim 1, wherein the material is removed with a cutting tool.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1A-1C: show a force-measuring element which comprises two subregions separated by an articulation site. Herein,
(2) FIG. 1A shows an embodiment without any external force application,
(3) FIG. 1B shows an embodiment of the force-measuring element with external force application and a deflection direction parallel to the bending plane, and
(4) FIG. 1C shows an embodiment of a force-measuring element with external force application and a deflection direction of a sub-region not parallel to the bending plane,
(5) FIGS. 2A-2D: show two sub-regions separated by an articulation site, wherein the articulation site in:
(6) FIG. 2A has an articulation site correction with a double trench and a parallel region,
(7) FIG. 2B has a flat depression,
(8) FIG. 2C has an evenly rounded depression which has an oval form, and
(9) FIG. 2D has a circular articulation site correction,
(10) FIGS. 3A-3E: show embodiments in which
(11) FIG. 3A shows a biconcave articulation site,
(12) FIG. 3B shows a multiple articulation site which is configured as a double articulation site,
(13) FIG. 3C shows a biconvex articulation site,
(14) FIG. 3D shows an articulation site with a parallel region, and
(15) FIG. 3E shows an articulation site with two rounded grooves, and
(16) FIG. 4: shows a schematic representation of the method sequence according to the invention for producing a force-measuring element.
DETAILED DESCRIPTION
(17) FIGS. 1A-1C show a force-measuring element 10 which is separated by an articulation site 20 into two sub-regions 11, 12. In FIG. 1A, without an external force application 15 (lacking in FIG. 1A the body axis 13 lies in the bending plane 14 of the articulation site 20. FIG. 1B shows an embodiment of the force-measuring element 10, wherein an external force application 15 acts on a sub-region 12. The geometry of the articulation site 20 is configured so that if a direction of the external force application 15 lies in the bending plane 14, the deflection direction 16 of the sub-region 12 is also in the bending plane 14. An articulation site geometry of this type is calculated to be error-free and needs no correction, provided the thickness and the position of the articulation site and therefore its mobility complies with the specifications. FIG. 1C shows an embodiment of a force-measuring element 10 with an articulation site geometry needing to be corrected. The sub-region 12 deflected by the external force application 15 has a deflection direction 16 which is not parallel to the bending plane 14. Furthermore, its body axis 13 does not lie in the bending plane 14. An articulation site geometry of this type must therefore be corrected so that the deflection direction 16 of the sub-region 12 lies in the bending plane 14 during an external force application 15. A deflection behavior of this type is generally undesirable, although it can be corrected through material removal of a suitable form and size, for example, through material removal using laser processing.
(18) FIGS. 2A-2D show a force-measuring element 10 with an articulation site 20 which separates two sub-regions 11, 12 of the force-measuring element 10 from one another. The biconcave articulation site geometry configured here has been corrected using a laser and on the basis of a previously determined correction form 30. Herein, FIG. 2A shows a correction form which has a double trench with regions that are parallel to one another, FIG. 2B shows a correction form 30 with depressions perpendicular to the articulation site surface and an evenly flat depression plane, FIG. 2C shows a depression which is curved in its depth and has a half-oval form on its surface, and FIG. 2D shows a point-shaped or circular correction form which can penetrate the articulation site 20 partially or entirely. Such correction forms 30 of the articulation site geometry change the deflection behavior of the two sub-region 11, 12 of the force-measuring element 10 differently. Thus, first, the mobility can be increased, although alternatively or additionally, the deflection direction 16 of the subregion 12 and/or the exact position of the rotation point can be changed. Thus a twist or a vertical inclination sensitivity of the sub-region 12 can be corrected and a deflection direction 16 caused by an external force application 15 which is parallel to the bending plane 14 can be achieved.
(19) FIGS. 3A-3E show different embodiments of an articulation site which has been created or corrected using a laser. Thus, FIG. 3A shows a biconcave articulation site, FIG. 3B shows a multiple articulation site which is configured as a double articulation site, FIG. 3C shows a biconvex articulation site, FIG. 3D shows an articulation site with a parallel region and FIG. 3E shows an articulation site with two rounded grooves.
(20) FIG. 4 shows a schematic representation of the method sequence according to the invention for producing a force-measuring element 10, said method comprising a correction of the articulation site geometry. In a first method step, not shown here, an articulation site 20 is created on a force-measuring element 10 through cutting material removal, so that the articulation site 20 separates two sub-regions 11, 12 of the force-measuring element 10 from one another. In a second method step, the force-measuring element 10 with an articulation site 20 is subjected to testing of the deflection behavior. The measurement values determined are compared with a predefined specification and it is tested whether this specification has been complied with or not. In the first case, the force-measuring element 10 is correctly configured and can be used directly. In the latter case, it is tested in a next method step whether an articulation site correction can compensate for the measured error in the force-measuring element 10. If the specification for a particular accuracy class of the force-measuring element 10 is achievable with an articulation site correction, then an articulation site correction of this type is carried out in a next method step. Herein, the previously determined deviations of the deflection behavior of the force-measuring element 10 from the data specification are converted into correction parameters so that a suitable correction form can be determined and used at the articulation site 20.
(21) If however, the result of the estimation of prospects for the success of a correction is that it cannot sufficiently reduce or remedy the errors, then in a next method step, it is tested whether the force-measuring element 10 can be assigned to a lower accuracy class or whether the errors are so serious that it is to be assigned as a defective product to rejected goods. On the basis of a correction method of this type, therefore, defective item production and therefore the manufacturing costs of force-measuring elements are reduced.
(22) The embodiments covered by the specific description above and shown in the figures are merely illustrative exemplary embodiments of the present invention. A broad spectrum of possible variations will be evident to a person skilled in the art, based on the present disclosure.
REFERENCE SIGNS
(23) 10 Force-measuring element 11 First sub-region of the force-measuring element 12 Second sub-region of the force-measuring element 13 Body axis 14 Bending plane 15 Direction of external force application 16 Deflection direction 20 Articulation site 21 Thickness of the articulation site 30 Correction form
