EP1771707A1 - Force sensing device - Google Patents

Force sensing device

Info

Publication number
EP1771707A1
EP1771707A1 EP05769891A EP05769891A EP1771707A1 EP 1771707 A1 EP1771707 A1 EP 1771707A1 EP 05769891 A EP05769891 A EP 05769891A EP 05769891 A EP05769891 A EP 05769891A EP 1771707 A1 EP1771707 A1 EP 1771707A1
Authority
EP
European Patent Office
Prior art keywords
measuring device
force
rigid housing
force measuring
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05769891A
Other languages
German (de)
French (fr)
Inventor
Franz Stadler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Continental Automotive GmbH
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP1771707A1 publication Critical patent/EP1771707A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01G—WEIGHING
    • G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
    • G01G19/40—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight
    • G01G19/413—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means
    • G01G19/414—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means using electronic computing means only
    • G01G19/4142—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means using electronic computing means only for controlling activation of safety devices, e.g. airbag systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01G—WEIGHING
    • G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
    • G01G19/40—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight
    • G01G19/413—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means
    • G01G19/414—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means using electronic computing means only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
    • B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
    • B60N2/002—Seats provided with an occupancy detection means mounted therein or thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/015—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
    • B60R21/01512—Passenger detection systems
    • B60R21/01516—Passenger detection systems using force or pressure sensing means

Definitions

  • the invention relates to a force measuring device.
  • the Kraft ⁇ measuring device has an integrally manufactured housing made of metal, with upper and lower rigid housing parts which are resiliently movable to each other. Between the two rigid housing parts a deflection sensor is mounted, which can detect the deflection of the two rigid housing parts to each other and pass as an electrical signal.
  • occupant restraining means for example front airbags, side airbags, knee airbags, curtain airbags, etc.
  • front airbags for example front airbags, side airbags, knee airbags, curtain airbags, etc.
  • later repair costs after an unnecessary triggering, for example, in an unoccupied
  • the housing of the force ⁇ measuring device can be made in one piece and made of spring metal, with rigid housing parts (220) and (222) and Federmit ⁇ means (232, 234), the rigid housing parts (220, 222) (Fi ⁇ gur 4 and Column 8, lines 18 to 27).
  • a deflection sensor is arranged, for example, an inductive deflection sensor (190, 192, 194, 196, 198) ( Figure 3), which determine a deflection of the star ⁇ ren housing parts (220, 222) and into a measuring signal that provides information about the force acting on the force measuring device.
  • an inductive deflection sensor 190, 192, 194, 196, 198
  • German laid-open specification DE 101 45 370 A1 discloses a similar force measuring device made of a one-piece metal housing (FIG. 4b and column 6, paragraph [0059]), but with a different sensor principle.
  • the known force measuring devices in order to be able to use them profitably in a motor vehicle, have to be made very small in order to take into account the limited installation space between a vehicle seat and the vehicle chassis, and on the other hand to be extremely dimensionally stable over the entire service life of a vehicle Vehicle, usually at least 15 years, to avoid systematic erroneous measurements of the deflection sensor over time as possible.
  • these two requirements of the known force measuring devices are conflicting and seem incompatible with each other:
  • For a permanently dimensionally stable housing the very heavy in the operation of a motor vehicle weight loads of up to 1.2 t, speaks a very massive and rather large housing for the force measuring device.
  • a small space er ⁇ calls rather a filigree, small housing.
  • Object of the present invention is to provide a Kraftmessvor ⁇ direction with a permanently dimensionally stable, possible hystere ⁇ seelle housing, which is at the same time very small and can be easily manufactured.
  • the object is achieved by a force measuring device according to claim 1.
  • the force measuring device comprises a einstü ⁇ ckiges metal housing.
  • the housing comprises an upper rigid housing part and a lower rigid housing part, which are connected to one another via U-shaped spring elements and which are resiliently movable against one another under the action of a force along a movement axis.
  • the spring elements are arranged symmetrically with respect to one another with respect to a sectional area parallel to the movement axis.
  • a deflection sensor for detecting the relative movement of the two rigid housing parts relative to each other is mounted between the upper and lower rigid housing parts.
  • the housing is manufactured in metal injection molding (MIM) technology.
  • MIM technology has hitherto only been known from other technical fields. Reference may be made here, for example, to a publication by Hans Schweiger GmbH, the 03.März.2004 on the website was callable, in which the MIM manufacturing process for various fürsgebie ⁇ te is described te.
  • fine metal powder is mixed with primary binders and granulated, there arises a so-called feedstock.
  • the feedstock is melted in an injection molding machine and injected in a mold to the molding. After cooling, the components are removed as so-called green compacts. On closing ⁇ the binder is expelled in an oven from the green bodies.
  • the binderless components are now called Braunlin ⁇ ge and are then sintered in a high-temperature furnace.
  • the MIM technology combines the freedom of forming plastic injection molding with powder metallurgy.
  • the MIM process therefore offers the possibility of cost-effectively producing highly integrated metal parts with complex geometries and high precision in large quantities.
  • FIG 1 shows a first embodiment of a fiction, modern ⁇ force measuring device in cross-section, Figure 2, the force-measuring device according to FIG 1 in perspek ⁇ TiVi shear representation,
  • FIG. 3 is a plan view of the force measuring device according to FIG. 1,
  • FIG. 4 shows the force-measuring device of FIG. 1 in a cross-sectional view along the sectional area A-A
  • Figure 5 shows an enlarged partial view of Figure 4
  • Figure 6 shows a second embodiment of a dung OF INVENTION ⁇ proper force measuring device in a Quer ⁇ sectional view along the AA cut surface as shown in Figure 1, and
  • FIG. 7 shows an enlarged partial section of FIG. 6.
  • FIG. 1 shows an advantageous embodiment of a force device 1 according to the invention, consisting of a one-piece housing 2 which is used in Metal Injection Molding (MIM) technology. is manufactured.
  • the housing has an upper Gezzau ⁇ seteil 25 and a lower housing part 26, which are designed to be rigid compared to these two Gezzausetei ⁇ le 25, 26 connecting the U-shaped spring members 21 and 22 so that the two rigid housing parts 25 and 26 Although they can move toward or away from each other under the influence of a gravitational force, they themselves ideally do not deform.
  • MIM Metal Injection Molding
  • a deflection sensor 6 is mounted, which detect a relative movement of the two housing parts 25, 26 to each other and can convert into an electrical signal, which is guided via a cable connection, not shown via a connector 5 to a transmitter , or in a Ausreteelekt ⁇ ronik within the connector 5 is further processed.
  • This signal is supplied to a Insassenschutz ⁇ also not shown device and is there as information about the force acting on the force measuring device 1 by weight to Availability checked ⁇ supply, due to which an occupant restraint means is triggered if given ⁇ adjusted.
  • the limbs form the two spring elements 22 and 21 a sharp ⁇ th angle ⁇ .
  • each of the spring elements starting from the obe ⁇ ren rigid housing part 25 continuously until it at the start of the bend to the U-bend a smallest wall thickness d ER- enough. From this point, the wall thickness around the vertex ⁇ point of the U-loop increases again, decreases again after the loop loop and remains constant until the transition into the lower rigid housing part 26. Since the sectional area AA represents a plane of symmetry of the spring element, the Ver ⁇ run the wall thickness d along the spring element equal to the spring element 22nd
  • the illustrated housing 1 as two integral components behind each of the two illustrated spring loops 21 and 22 each have a fastening tab 4, by means of which the force-measuring device 1 is rigidly connected to the vehicle chassis via two screws 7 in the installed state.
  • a fastening tab 4 by means of which the force-measuring device 1 is rigidly connected to the vehicle chassis via two screws 7 in the installed state.
  • other fastening means could also be used, for example Nie ⁇ th or the like.
  • FIG. 2 shows the force-measuring device of FIG. 1 in a perspective view. It can be seen that, in turn, behind the two fastening means 4 with the associated screws 7, a further pair of U-shaped spring elements 24 and 25 are arranged symmetrically about the two rigid housing parts 25 and 26. Based on this presentation, it is particularly clear how with the help of the possibility of a very delicate design of the housing 2 in MIM technology, the four illustrated spring loops 21, 22, 23, 24 can be made so narrow that the attachment points of the force measuring device 1 within the same Base surface are ange ⁇ arranged, which is occupied by the entire housing 2 together with spring elements 21, 22, 23 and 24. This base area is shown again in plan view in FIG.
  • Figure 4 never shows a cross section through the housing 2 be ⁇ already shown force-measuring device 1 along the Thomasli ⁇ AA of Figure 1. From these cross-sectional view to the operation of additional Matterlaststoffelemen- th 8, will be explained 9, which in the two figures
  • the two overload protection elements 8. 9 are fixedly connected to the upper star ⁇ ren housing part 25, for example by means of egg ⁇ ner screw.
  • the two overload protection elements 8, 9 are each spaced from the lower rigid housing part 26 through an approximately constant narrow air gap.
  • the two overload protection elements 8 and 9 emerge from the Ge ⁇ housing 2 out as soon as a force on the force introduction
  • FIG. 6 shows a further advantageous embodiment of a force measuring device 1 according to the invention in a cross-sectional view similar to FIG.
  • the upper force introduction means 3 is not designed as a screw with external thread; Rather, the upper rigid overall casing part 25 has an internal thread, a ⁇ is screwed into the screw, which is also guided above the top rigid housing part 25 through a recess of the motor vehicle seat 10 or of a rigidly connected to the vehicle seat part. In this way, the force-measuring device 1 is rigidly connected to the motor vehicle seat 10.
  • FIG. 1 a partial section through one of the two fastening screws 7 is shown.
  • the screw 7 shown in section appears to be in front of the spring loop 21 by their highlighted representation in cross section ⁇ ; in fact, however, it is arranged behind this loop 21, analogous to the fastening screw 7, which is furthermore illustrated, behind the spring loop 22.
  • a force-measuring device 1 in the installed state, that is to say in the present case: two screws 7 are made from the direction of the upper rigid housing part 25 by means of recessing. ments passed out of the lower rigid housing part 26 and bolted with its screw thread on the vehicle seat tone ⁇ turned side of the force measuring device 1 with the vehicle chassis.
  • this case consists in the shown execution example a form-locking contact surface of a sectionbe ⁇ realm of screws 7 to the corresponding Befest Trentsla ⁇ rule 4, the lower part of the rigid housing part 26th
  • one or more mechanical attachment point (s) can also be used to enable a rigid attachment of the force-measuring device.
  • the upper rigid housing portion 25 contacts in the installed to stand ⁇ the force measuring device 1, neither since even the re On the other fastening means 7 illustrated, but is under
  • a partial region 25 "of the upper, rigid housing part 25 engages under the screw head of the screw 7, so that the
  • Portion 25 " is arranged between the screw head of the screw 7 and the lower rigid housing part 26 In BEWE ⁇ supply device 60 thus formed, in part, a gap a zwi ⁇ rule the screw head of the screw 7 and the underlie- the partial region 25.”; On the other hand, a further gap b is created between the cross-engaging partial area 25 "and the lower rigid housing part 26, thirdly, a further gap arises Gap (not labeled) perpendicular to the direction property ⁇ se 60 between the screw and the portion 25 ".
  • the force measuring device 1 can be subjected to force in the direction of the movement direction axis 60 until the gap b closes due to the deflection of the upper rigid housing part 25.
  • a mechanical stop is created in this deflection direction
  • mechanical overstressing in the case of oppositely directed expansion of the force-measuring device 1 is prevented by a mechanical abutment of the portion 25 "on the lower rigid housing part 26, the gap a being closed.
  • the mechanical stop surface shown here could also be reduced only from a stop point, if appropriate.

Abstract

The invention relates to a force-sensing device (1) comprising a monolithic metal housing (2). Said housing (2) is provided with a top rigid housing part (25) and a bottom rigid housing part (26) which are interconnected via U-shaped spring elements (21, 22, 23, 24) while being movable in a springy manner towards each other along an axis of movement (60) when a force is applied thereto. The spring elements (21, 22, 23, 24) are disposed symmetric to one another relative to a cross-sectional area (AA) that runs parallel to the axis of movement (60). A deflection sensor (6) is mounted between the top and bottom rigid housing parts (25, 26) in order to detect the relative movement of the two rigid housing parts (25, 26) towards each other. According to the invention, the housing (2) is produced with the aid of a metal injection molding (MIM) technique.

Description

Beschreibungdescription
KraftmessVorrichtungForce measuring device
Die Erfindung betrifft eine Kraftmessvorrichtung. Die Kraft¬ messvorrichtung weist ein einstückig gefertigtes Gehäuse aus Metall auf, mit oberen und unteren starren Gehäuseteilen, die zueinander federnd bewegbar sind. Zwischen die beiden starren Gehäuseteile ist ein Auslenksensor angebracht, der die Aus- lenkung der beiden starren Gehäuseteile zueinander erfassen und als elektrisches Signal weitergeben kann.The invention relates to a force measuring device. The Kraft¬ measuring device has an integrally manufactured housing made of metal, with upper and lower rigid housing parts which are resiliently movable to each other. Between the two rigid housing parts a deflection sensor is mounted, which can detect the deflection of the two rigid housing parts to each other and pass as an electrical signal.
Im Bereich des Insassenschutzes in Kraftfahrzeugen wird es in den letzten Jahren immer wichtiger die Auslösung von Insas- senrückhaltemitteln, beispielsweise Frontairbags, Seitenair- bags, Knieairbags, Vorhangairbags, etc. an gegebenenfalls im Entfaltungsbereich der Insassenrückhaltemittel befindliche Fahrzeuginsassen anzupassen oder sogar gänzlich zu unterdrü¬ cken, um einerseits spätere Reparaturkosten nach einer unnö- tigen Auslösung, beispielsweise bei einem nicht belegtenIn the field of occupant protection in motor vehicles, the triggering of occupant restraining means, for example front airbags, side airbags, knee airbags, curtain airbags, etc., is increasingly important in recent years to be adjusted or even completely suppressed for vehicle occupants who are possibly located in the deployment area of the occupant restraint means on the one hand later repair costs after an unnecessary triggering, for example, in an unoccupied
Fahrzeugsitz zu sparen, und andererseits um bestimmte Perso¬ nengruppen nicht durch ein ungeeignetes Auslöseverhalten des Insassenrückhaltemittels zusätzlich zu gefährden, beispiels¬ weise Kinder oder sehr kleine Erwachsene. Es ist also nicht nur wichtig, die Anwesenheit einer Person auf einem Kraft¬ fahrzeugsitz festzustellen, sondern darüber hinaus sogar klassifizierende Eigenschaften der Person, beispielsweise das Körpergewicht. Zu nennen ist in diesem Zusammenhang die Crash-Norm FMVSS208, deren Einhaltung immer mehr von Fahr- zeugherstellern gefordert wird und die eine Klassifizierung einer Person nach einem Gewicht festschreibt, um im Falle ei¬ ner Kollision die Ansteuerung eines Insassenrückhaltemittels ggf. in bekannter Weise an die erkannte Person anzupassen. Aus der Druckschrift DE 100 04 484 Al ist es bekannt, zum Er¬ kennen des Gewichts einer Person auf einem Kraftfahrzeugsitz Kraftmessvorrichtungen zwischen dem Fahrzeugsitz und dem Fahrzeugchassis anzuordnen. Dabei kann das Gehäuse der Kraft¬ messvorrichtung einstückig und aus Federmetall gefertigt sein, mit starren Gehäuseteilen (220) und (222) und Federmit¬ teln (232, 234), die die starren Gehäuseteile (220, 222) (Fi¬ gur 4 und Spalte 8, Zeilen 18 bis 27) verbinden. Zwischen den beiden starren Gehäuseteilen (220, 222) ist ein Auslenksensor angeordnet, beispielsweise ein induktiver Auslenksensor (190, 192, 194, 196, 198) (Figur 3), der eine Auslenkung der star¬ ren Gehäuseteile (220, 222) feststellen und in ein Messsignal umwandeln kann, das Aufschluss über die auf die Kraftmessvor- richtung wirkende Kraft gibt.Saving vehicle seat, and also to certain Perso ¬ ¬ no example as children or very small adults nengruppen by an unsuitable triggering behavior of the occupant restraint means compromising additionally. It is therefore not only important to determine the presence of a person on a force ¬ vehicle seat, but beyond even classifying properties of the person, such as the body weight. To call the Crash norm FMVSS208, compliance with which is increasingly demanded by vehicle manufacturers and the classification of a person for a weight is fixed writes in this connection to the case ei ¬ ner collision controlling an occupant restraint means necessary, in a known manner to adapt the recognized person. From the document DE 100 04 484 Al it is known to He ¬ know the weight of a person on a motor vehicle seat force measuring devices between the vehicle seat and the vehicle chassis to order. In this case, the housing of the force ¬ measuring device can be made in one piece and made of spring metal, with rigid housing parts (220) and (222) and Federmit¬ means (232, 234), the rigid housing parts (220, 222) (Fi¬ gur 4 and Column 8, lines 18 to 27). Between the two rigid housing parts (220, 222), a deflection sensor is arranged, for example, an inductive deflection sensor (190, 192, 194, 196, 198) (Figure 3), which determine a deflection of the star¬ ren housing parts (220, 222) and into a measuring signal that provides information about the force acting on the force measuring device.
Die deutsche Offenlegungsschrift DE 101 45 370 Al offenbart eine ähnliche Kraftmessvorrichtung aus einem einstückigen Me¬ tallgehäuse (Figur 4b und Spalte 6, Absatz [0059]), aller- dings mit einem unterschiedlichen Sensorprinzip.German laid-open specification DE 101 45 370 A1 discloses a similar force measuring device made of a one-piece metal housing (FIG. 4b and column 6, paragraph [0059]), but with a different sensor principle.
Die bekannten Kraftmessvorrichtungen müssen, um sie nutzbrin¬ gend in einem Kraftfahrzeug einsetzen zu können, zum einen sehr klein gefertigt werden, um den beschränkten Bauraum zwi- sehen einem Fahrzeugsitz und dem Fahrzeugchassis Rechnung zu tragen, und zum anderen äußerst formstabil über die gesamte Lebensdauer eines Fahrzeugs sein, üblicherweise mindestens 15 Jahre, um systematische Fehlmessungen des Auslenksensors im Laufe der Zeit möglichst zu vermeiden. Diese beiden Anforde- rungen an die bekannten Kraftmessvorrichtungen sind jedoch widerstreitend und scheinen unvereinbar miteinander: Für ein dauerhaft formstabiles Gehäuse, das den im Betrieb eines Kraftfahrzeugs sehr großen Gewichtsbelastungen von bis zu 1,2 t standhält, spricht ein sehr massives und eher großes Gehäuse für die Kraftmessvorrichtung. Ein kleiner Bauraum er¬ fordert eher ein filigranes, kleines Gehäuse.The known force measuring devices, in order to be able to use them profitably in a motor vehicle, have to be made very small in order to take into account the limited installation space between a vehicle seat and the vehicle chassis, and on the other hand to be extremely dimensionally stable over the entire service life of a vehicle Vehicle, usually at least 15 years, to avoid systematic erroneous measurements of the deflection sensor over time as possible. However, these two requirements of the known force measuring devices are conflicting and seem incompatible with each other: For a permanently dimensionally stable housing, the very heavy in the operation of a motor vehicle weight loads of up to 1.2 t, speaks a very massive and rather large housing for the force measuring device. A small space er¬ calls rather a filigree, small housing.
Aufgabe der vorliegenden Erfindung ist es, eine Kraftmessvor¬ richtung mit einem dauerhaft formstabilen, möglichst hystere¬ sefreien Gehäuse zu schaffen, das gleichzeitig sehr klein ist und einfach gefertigt werden kann.Object of the present invention is to provide a Kraftmessvor¬ direction with a permanently dimensionally stable, possible hystere ¬ sefreien housing, which is at the same time very small and can be easily manufactured.
Die Aufgabe wird gelöst durch eine Kraftmessvorrichtung gemäß Anspruch 1.The object is achieved by a force measuring device according to claim 1.
Vorteilhafte Ausführungsformen sind in den Unteransprüchen angegeben, wobei jede beliebige sinnvolle Kombination von Merkmalen der Unteransprüche mit dem Hauptanspruch unter Schutz gestellt werden soll.Advantageous embodiments are specified in the subclaims, wherein any meaningful combination of features of the subclaims with the main claim is to be put under protection.
Die erfindungsgemäße Kraftmessvorrichtung umfasst ein einstü¬ ckiges Gehäuse aus Metall. Das Gehäuse umfasst einen oberen starren Gehäuseteil und einen unteren starren Gehäuseteil, die über U-förmige Federelemente miteinander verbunden sind und die unter Einwirken einer Kraft entlang einer Bewegungs¬ achse federnd gegeneinander bewegbar sind. Die Federelemente sind bezüglich einer Schnittfläche parallel zur Bewegungsach- se symmetrisch zueinander angeordnet. Zwischen den oberen und unteren starren Gehäuseteilen ist ein Auslenksensor zur Er¬ fassung der Relativbewegung der beiden starren Gehäuseteile zueinander angebracht. Erfindungsgemäß ist das Gehäuse in Me- tal Injection Molding (MIM) Technologie gefertigt.The force measuring device according to the invention comprises a einstü ¬ ckiges metal housing. The housing comprises an upper rigid housing part and a lower rigid housing part, which are connected to one another via U-shaped spring elements and which are resiliently movable against one another under the action of a force along a movement axis. The spring elements are arranged symmetrically with respect to one another with respect to a sectional area parallel to the movement axis. A deflection sensor for detecting the relative movement of the two rigid housing parts relative to each other is mounted between the upper and lower rigid housing parts. According to the invention, the housing is manufactured in metal injection molding (MIM) technology.
Die Verwendung der MIM Technologie ist bislang nur aus ande¬ ren technischen Bereichen bekannt, hingewiesen sei hier bei¬ spielsweise auf eine Veröffentlichung der Fa. Hans Schweiger GmbH, die am 03.März.2004 auf der Internetseite aufrufbar war, in der der MIM Herstellungsprozess für verschiedene Anwendungsgebie¬ te beschrieben wird.The use of MIM technology has hitherto only been known from other technical fields. Reference may be made here, for example, to a publication by Hans Schweiger GmbH, the 03.März.2004 on the website was callable, in which the MIM manufacturing process for various Anwendungsgebie ¬ te is described te.
Bei der MIM Technik, auch bekannt als Pulvermetallspritzgie¬ ßen, wird feines Metallpulver mit primären Bindern gemischt und granuliert, es entsteht ein so genannter Feedstock. Der Feedstock wird in einer Spritzgießmaschine aufgeschmolzen und in einem Werkzeug zum Formteil gespritzt. Nach der Abkühlung werden die Bauteile als so genannte Grünlinge entnommen. An¬ schließend wird der Binder in einem Ofen aus den Grünlingen ausgetrieben. Die binderlosen Bauteile heißen jetzt Braunlin¬ ge und werden anschließend in einem Hochtemperaturofen gesin- tert.In the MIM technique, also known as SEN Pulvermetallspritzgie ¬, fine metal powder is mixed with primary binders and granulated, there arises a so-called feedstock. The feedstock is melted in an injection molding machine and injected in a mold to the molding. After cooling, the components are removed as so-called green compacts. On closing ¬ the binder is expelled in an oven from the green bodies. The binderless components are now called Braunlin¬ ge and are then sintered in a high-temperature furnace.
Die MIM Technik verbindet dabei die Formgebungsfreiheit des KunststoffSpritzgießens mit der Pulvermetallurgie. Das MIM- Verfahren bietet deshalb die Möglichkeit, hochintegrierte Me- tallteile mit komplexen Geometrien und in hoher Präzision in großen Stückzahlen kostengünstig herzustellen.The MIM technology combines the freedom of forming plastic injection molding with powder metallurgy. The MIM process therefore offers the possibility of cost-effectively producing highly integrated metal parts with complex geometries and high precision in large quantities.
Mit dem MIM-Verfahren ist es deshalb möglich, Gehäusewandun¬ gen mit sehr exakte Dicken herzustellen und somit sehr exakt berechnete Form- und Dickenverläufe in einem Metallgehäuse einer erfindungsgemäßen Kraftmessvorrichtung zu erreichen. Dadurch kann ein sehr kleines federndes Gehäuse hergestellt werden, so dass dennoch bei einer geforderten maximalen Nenn¬ belastung von beispielsweise 150 kg auf die Kraftmessvorrich- tungen eine maximale innere Spannung von 350 Newton/mm2 an keiner Stelle im Gehäuse überschritten wird und gleichzeitig eine Auslenkung der starren Gehäuseteile zueinander von min¬ destens 1 μm pro kg auflastenden Gewichts erreicht wird. Außerdem ist es durch die Einstückigkeit des erfindungsgemä¬ ßen Gehäuses möglich, bislang aufwändige Fügeprozesse zwi¬ schen verschiedenen Bestandteilen des Gehäuses zu vermeiden, wodurch - in Folge der reduzierten Anzahl von Fügekanten - Hysterese-Erscheinungen bei der erfindungsgemäßen Kraftmess¬ vorrichtung erheblich reduziert werden können.With the MIM method it is therefore possible to produce housing walls with very exact thicknesses and thus to achieve very precisely calculated shape and thickness courses in a metal housing of a force measuring device according to the invention. As a result, a very small resilient housing can be produced, so that at a required maximum rated load of, for example, 150 kg on the force measuring devices, a maximum internal stress of 350 Newtons / mm 2 is not exceeded at any point in the housing and at the same time a deflection the rigid housing parts to each other of at least 1 micron per kg weight charged is achieved. In addition, it is possible by the integral nature of the invention ¬ Shen housing hitherto complex joining processes between ¬ different components of the housing to avoid, which - due to the reduced number of joint edges - hysteresis phenomena in the force measuring inventive device can be significantly reduced.
Vorteilhafte Ausführungsformen von erfindungsgemäßen Vorrich- tungen sind in der nachfolgenden Figurenbeschreibung be¬ schrieben. Es zeigen:Advantageous embodiments of devices according to the invention are described in the following description of the figures. Show it:
Figur 1 ein erstes Ausführungsbeispiel für eine erfindungs¬ gemäße Kraftmessvorrichtung im Querschnitt, Figur 2 die Kraftmessvorrichtung gemäß Figur 1 in perspek¬ tivischer Darstellung,1 shows a first embodiment of a fiction, modern ¬ force measuring device in cross-section, Figure 2, the force-measuring device according to FIG 1 in perspek¬ TiVi shear representation,
Figur 3 die Kraftmessvorrichtung gemäß Figur 1 in Drauf¬ sicht,FIG. 3 is a plan view of the force measuring device according to FIG. 1,
Figur 4 die Kraftmessvorrichtung aus Figur 1 in Quer- Schnittsdarstellung entlang der Schnittfläche A-A,FIG. 4 shows the force-measuring device of FIG. 1 in a cross-sectional view along the sectional area A-A,
Figur 5 eine vergrößerte Teildarstellung der Figur 4, Figur 6 ein zweites Ausführungsbeispiel für eine erfin¬ dungsgemäße Kraftmessvorrichtung in einer Quer¬ schnittsdarstellung entlang der Schnittfläche A-A wie in Figur 1 und5 shows an enlarged partial view of Figure 4, Figure 6 shows a second embodiment of a dung OF INVENTION ¬ proper force measuring device in a Quer¬ sectional view along the AA cut surface as shown in Figure 1, and
Figur 7 ein vergrößerter Teilausschnitt der Figur 6.FIG. 7 shows an enlarged partial section of FIG. 6.
Elemente gleicher Konstruktion oder Funktion sind figuren¬ übergreifend mit den gleichen Bezugszeichen gekennzeichnet.Elements of the same construction or function are marked with the same reference numbers across the figures.
Figur 1 zeigt eine vorteilhafte Ausführungsform einer erfin¬ dungsgemäßen Kraftvorrichtung 1, bestehend aus einem einstü¬ ckigen Gehäuse 2, das in Metal Injection Molding (MIM) Tech- nologie gefertigt ist. Das Gehäuse weist einen oberen Gehäu¬ seteil 25 und einen unteren Gehäuseteil 26 auf, die starr ausgebildet sind im Vergleich zu den diese beiden Gehäusetei¬ le 25, 26 verbindenden U-förmigen Federelementen 21 und 22, so dass die beiden starren Gehäuseteile 25 und 26 sich zwar unter Einwirken einer Gewichtskraft zueinander hin- oder von¬ einander wegbewegen können, sich jedoch selbst idealerweise nicht verformen. Zwischen den beiden starren Gehäuseteilen 25 und 26 ist ein Auslenksensor 6 angebracht, der eine Relativ- bewegung der beiden Gehäuseteile 25, 26 zueinander erfassen und in ein elektrisches Signal wandeln kann, das über eine nicht gezeigte Kabelverbindung über einen Stecker 5 zu einer Auswerteelektronik geführt wird, oder in einer Auswerteelekt¬ ronik innerhalb des Steckers 5 weiterverarbeitet wird. Dieses Signal wird einer ebenfalls nicht gezeigten Insassenschutz¬ vorrichtung zugeführt und steht dort als Information über das auf die Kraftmessvorrichtung 1 wirkende Gewicht zur Verfü¬ gung, aufgrund derer ein Insassenrückhaltemittel gegebenen¬ falls angepasst ausgelöst wird.FIG. 1 shows an advantageous embodiment of a force device 1 according to the invention, consisting of a one-piece housing 2 which is used in Metal Injection Molding (MIM) technology. is manufactured. The housing has an upper Gehäu ¬ seteil 25 and a lower housing part 26, which are designed to be rigid compared to these two Gehäusetei ¬ le 25, 26 connecting the U-shaped spring members 21 and 22 so that the two rigid housing parts 25 and 26 Although they can move toward or away from each other under the influence of a gravitational force, they themselves ideally do not deform. Between the two rigid housing parts 25 and 26, a deflection sensor 6 is mounted, which detect a relative movement of the two housing parts 25, 26 to each other and can convert into an electrical signal, which is guided via a cable connection, not shown via a connector 5 to a transmitter , or in a Auswerteelekt¬ ronik within the connector 5 is further processed. This signal is supplied to a Insassenschutz¬ also not shown device and is there as information about the force acting on the force measuring device 1 by weight to Availability checked ¬ supply, due to which an occupant restraint means is triggered if given ¬ adjusted.
Im Sinne der eingangs erwähnten wünschenswerten geringen me¬ chanischen Spannungen im Gehäuse 22, selbst unter Einwirken einer Kraft, die über ein Krafteinleitmittel 3 von einem Kraftfahrzeugsitz auf das obere starre Gehäuseteil 25 und so- mit auf die Kraftmessvorrichtung 1 aufgebracht wird, bilden die Schenkel der beiden Federelemente 22 und 21 einen spitz¬ ten Winkel α.In the sense of the above-mentioned desirable low mechanical stresses in the housing 22, even under the action of a force, which is applied to the upper rigid housing part 25 and thus to the force-measuring device 1 via a force introduction means 3 from a motor vehicle seat, the limbs form the two spring elements 22 and 21 a sharp ¬ th angle α.
Weiterhin im Sinne einer weitgehend gleichmäßigen Spannungs- Verteilung im ganzen Gehäuse 2 der Kraftmessvorrichtung 1 verjüngt sich jedes der Federelemente ausgehend von dem obe¬ ren starren Gehäuseteil 25 kontinuierlich bis es beim Beginn der Biegung zur U-Schlaufe eine geringste Wanddicke d er- reicht. Ab diesem Punkt nimmt die Wandstärke um den Scheitel¬ punkt der U-Schlaufe wieder zu, verringert sich nach der Schlaufenwindung wieder und bleibt konstant bis zum Übergang in das untere starre Gehäuseteil 26. Da die Schnittfläche AA eine Symmetrieebene des Federelements darstellt, ist der Ver¬ lauf der Wanddicke d entlang des Federelements gleich dem des Federelements 22.Furthermore, in terms of a substantially uniform stress distribution throughout the housing 2 of the force measuring device 1 is tapered, each of the spring elements starting from the obe ¬ ren rigid housing part 25 continuously until it at the start of the bend to the U-bend a smallest wall thickness d ER- enough. From this point, the wall thickness around the vertex ¬ point of the U-loop increases again, decreases again after the loop loop and remains constant until the transition into the lower rigid housing part 26. Since the sectional area AA represents a plane of symmetry of the spring element, the Ver ¬ run the wall thickness d along the spring element equal to the spring element 22nd
Weiterhin weist das dargestellte Gehäuse 1 als zwei integrale Bestandteile hinter jeder der beiden dargestellten Feder¬ schlaufen 21 und 22 jeweils eine Befestigungslasche 4 auf, mit Hilfe derer die Kraftmessvorrichtung 1 über zwei Schrau¬ ben 7 im eingebauten Zustand starr mit dem Fahrzeugchassis verbunden sind. An der Stelle von Schrauben könnten auch an- dere Befestigungsmittel verwendet werden, beispielsweise Nie¬ ten oder ähnliches.Furthermore, the illustrated housing 1 as two integral components behind each of the two illustrated spring loops 21 and 22 each have a fastening tab 4, by means of which the force-measuring device 1 is rigidly connected to the vehicle chassis via two screws 7 in the installed state. At the location of screws, other fastening means could also be used, for example Nie ¬ th or the like.
Figur 2 zeigt die Kraftmessvorrichtung der Figur 1 in per¬ spektivischer Darstellung. Man erkennt, dass wiederum hinter den beiden Befestigungsmitteln 4 mit den zugehörigen Schrau¬ ben 7 ein weiteres Paar von U-förmigen Federelementen 24 und 25 symmetrisch um die beiden starren Gehäuseteile 25 und 26 angeordnet ist. Anhand dieser Darstellung geht besonders deutlich hervor, wie mit Hilfe der Möglichkeit zu einer sehr filigranen Ausgestaltung des Gehäuses 2 in MIM-Technologie die vier dargestellten Federschlaufen 21, 22, 23, 24 so schmal gefertigt sein können, dass die Befestigungspunkte der Kraftmessvorrichtung 1 innerhalb derselben Grundfläche ange¬ ordnet sind, die vom gesamten Gehäuse 2 samt Federelementen 21, 22, 23 und 24 eingenommen wird. Diese Grundfläche wird in Figur 3 nochmals in Draufsicht gezeigt. Figur 4 zeigt einen Querschnitt durch das Gehäuse 2 der be¬ reits gezeigten Kraftmessvorrichtung 1 entlang der Schnittli¬ nie A-A der Figur 1. Anhand dieser Querschnittsdarstellung soll die Wirkungsweise von zusätzlichen Überlastschutzelemen- ten 8, 9 erläutert werden, die bereits in den beiden FigurenFIG. 2 shows the force-measuring device of FIG. 1 in a perspective view. It can be seen that, in turn, behind the two fastening means 4 with the associated screws 7, a further pair of U-shaped spring elements 24 and 25 are arranged symmetrically about the two rigid housing parts 25 and 26. Based on this presentation, it is particularly clear how with the help of the possibility of a very delicate design of the housing 2 in MIM technology, the four illustrated spring loops 21, 22, 23, 24 can be made so narrow that the attachment points of the force measuring device 1 within the same Base surface are ange¬ arranged, which is occupied by the entire housing 2 together with spring elements 21, 22, 23 and 24. This base area is shown again in plan view in FIG. Figure 4 never shows a cross section through the housing 2 be ¬ already shown force-measuring device 1 along the Schnittli¬ AA of Figure 1. From these cross-sectional view to the operation of additional Überlastschutzelemen- th 8, will be explained 9, which in the two figures
2 und 3 in Draufsicht des Gehäuses 2 dargestellt waren. Die beiden Überlastschutzelemente 8. 9 sind mit dem oberen star¬ ren Gehäuseteil 25 fest verbunden, beispielsweise mittels ei¬ ner Schraubverbindung.2 and 3 in plan view of the housing 2 were shown. The two overload protection elements 8. 9 are fixedly connected to the upper star ¬ ren housing part 25, for example by means of egg ¬ ner screw.
In Richtung zum unteren starren Gehäuseteil 26 hin nimmt der Durchmesser jeder der beiden Überlastschutzelemente 8 und 9 stufenförmig zu; die beiden Überlastschutzelemente 8, 9 sind jeweils zum unteren starren Gehäuseteil 26 hin durch einen etwa gleich bleibenden schmalen Luftspalt beabstandet.Towards the lower rigid housing part 26 towards the diameter of each of the two overload protection elements 8 and 9 increases in steps; the two overload protection elements 8, 9 are each spaced from the lower rigid housing part 26 through an approximately constant narrow air gap.
Zur Verdeutlichung der geometrischen Ausgestaltung der beiden Überlastschutzelemente 8, 9 ist ein in der Figur 4 durch eine schwarze Umrandung hervorgehobener Bereich der Kraftmessvor- richtung 1 in Figur 5 vergrößert dargestellt.To clarify the geometric configuration of the two overload protection elements 8, 9, a region of the force-measuring device 1, which is highlighted in FIG. 4 by a black border, is shown enlarged in FIG.
Die beiden Überlastschutzelemente 8 und 9 treten aus dem Ge¬ häuse 2 heraus sobald eine Kraft über das KrafteinleitmittelThe two overload protection elements 8 and 9 emerge from the Ge ¬ housing 2 out as soon as a force on the force introduction
3 in Richtung des unteren starren Gehäuseteils 26 einwirkt. Eine weitere Auslenkung der beiden starren Gehäuseteile 25 und 26 in Richtung zueinander bei einer weiter erhöhten Kraftwirkung wird erst dann verhindert, wenn die beiden Über¬ lastschutzelemente 8 und 9 so weit aus dem Gehäuse 2 hervor¬ getreten sind, dass sie in Formschluss mit dem Fahrzeug- Chassis treten.3 acts in the direction of the lower rigid housing part 26. A further deflection of the two rigid housing parts 25 and 26 in the direction of each other with a further increased force action is prevented only when the two Über¬ load protection elements 8 and 9 are so far out of the housing 2 ¬ kicked that they in positive engagement with the vehicle - Chassis kick.
Bei einer Krafteinwirkung in umgekehrter Richtung erfolgt ei¬ ne Auslenkung der beiden starren Gehäuseteile 25 und 26 zu- einander solange bis der Spalt zwischen dem unteren starren Gehäuseteil 26 und der Stufe in jedem der beiden Überlast¬ schutzelemente 8, 9 geschlossen ist.When a force is applied in the opposite direction, a deflection of the two rigid housing parts 25 and 26 takes place. each other until the gap between the lower rigid housing part 26 and the stage in each of the two overload ¬ protection elements 8, 9 is closed.
Figur 6 zeigt eine weitere vorteilhafte Ausführungsform einer erfindungsgemäßen Kraftmessvorrichtung 1 in einer zur Figur 1 analogen Darstellung im Querschnitt. Im Unterschied zur Figur 1 ist das obere Krafteinleitmittel 3 nicht als Schraube mit Außengewinde ausgeführt; vielmehr weist das obere starre Ge- häuseteil 25 ein Innengewinde auf, in das eine Schraube ein¬ geschraubt ist, die oberhalb des oberen starren Gehäuseteils 25 außerdem durch eine Ausnehmung aus dem Kraftfahrzeugsitz 10 oder aus einem starr mit dem Kraftfahrzeugsitz verbundenen Teil geführt ist. Auf diese Weise ist die Kraftmessvorrich- tung 1 starr mit dem Kraftfahrzeugsitz 10 verbunden.FIG. 6 shows a further advantageous embodiment of a force measuring device 1 according to the invention in a cross-sectional view similar to FIG. In contrast to Figure 1, the upper force introduction means 3 is not designed as a screw with external thread; Rather, the upper rigid overall casing part 25 has an internal thread, a ¬ is screwed into the screw, which is also guided above the top rigid housing part 25 through a recess of the motor vehicle seat 10 or of a rigidly connected to the vehicle seat part. In this way, the force-measuring device 1 is rigidly connected to the motor vehicle seat 10.
Im weiteren Unterschied zur Darstellung der Figur 1 ist ein Teilschnitt durch eine der beiden Befestigungsschrauben 7 dargestellt. Die in Schnittdarstellung gezeigte Schraube 7 erscheint durch ihre hervorgehobene Darstellung im Quer¬ schnitt vor der Federschlaufe 21 zu liegen; tatsächlich ist sie jedoch hinter dieser Schlaufe 21 angeordnet, analog zu der weiterhin dargestellten Befestigungsschraube 7 hinter der Federschlaufe 22.In a further difference from the representation of FIG. 1, a partial section through one of the two fastening screws 7 is shown. The screw 7 shown in section appears to be in front of the spring loop 21 by their highlighted representation in cross section ¬ ; in fact, however, it is arranged behind this loop 21, analogous to the fastening screw 7, which is furthermore illustrated, behind the spring loop 22.
Zum erleichterten Verständnis des konstruktiven Aufbaus und der folgenden Erläuterungen der Vorteile, die sich aus diesem konstruktiven Aufbau ergeben, ist der Schnitt durch die Schraube 7 in Figur 7 nochmals vergrößert dargestellt.To facilitate understanding of the structural design and the following explanations of the advantages arising from this structural design, the section through the screw 7 in Figure 7 is shown enlarged again.
Gezeigt ist eine Kraftmessvorrichtung 1 im eingebauten Zu¬ stand, das heißt im vorliegenden Fall: zwei Schrauben 7 sind aus Richtung des oberen starren Gehäuseteils 25 durch Ausneh- mungen aus dem unteren starren Gehäuseteil 26 hindurchgeführt und mit ihrem Schraubengewinde auf der dem Fahrzeugsitz abge¬ wandten Seite der Kraftmessvorrichtung 1 mit dem Fahrzeug- Chassis verschraubt. Dabei besteht im gezeigten Ausführungs- beispiel eine formschlüssige Berührungsfläche eines Teilbe¬ reichs der Schrauben 7 mit den entsprechenden Befestigungsla¬ schen 4, die Bestandteil des unteren starren Gehäuseteils 26 sind. Statt einer formschlüssigen Berührungsfläche kann auch beispielsweise ein oder mehrere mechanische Anschlagspunkt/e dienen, um eine starre Befestigung der Kraftmessvorrichtung zu ermöglichen.Shown is a force-measuring device 1 in the installed state, that is to say in the present case: two screws 7 are made from the direction of the upper rigid housing part 25 by means of recessing. ments passed out of the lower rigid housing part 26 and bolted with its screw thread on the vehicle seat abge ¬ turned side of the force measuring device 1 with the vehicle chassis. In this case consists in the shown execution example a form-locking contact surface of a Teilbe ¬ realm of screws 7 to the corresponding Befestigungsla¬ rule 4, the lower part of the rigid housing part 26th Instead of a form-fitting contact surface, for example, one or more mechanical attachment point (s) can also be used to enable a rigid attachment of the force-measuring device.
Das obere starre Gehäuseteil 25 berührt im eingebauten Zu¬ stand der Kraftmessvorrichtung 1 weder da eine noch das ande- re dargestellte Befestigungsmittel 7, sondern ist unterThe upper rigid housing portion 25 contacts in the installed to stand ¬ the force measuring device 1, neither since even the re On the other fastening means 7 illustrated, but is under
Krafteinwirkung beweglich gegen das untere starre Gehäuseteil 26. Sobald eine Druckkraft in Richtung des Fahrzeugchassis oder eine Zugkraft entgegengesetzt dazu (entlang der Bewe¬ gungsrichtungsachse 60) auf die Kraftmessvorrichtung 1 ein- wirkt bewegen sich folglich die beiden Gehäuseteile 25 und 26 aus ihrer Ruhelage aufeinander zu bzw. voneinander weg.Force to move against the lower rigid housing part 26. As soon as a compressive force in the direction of the vehicle body or a pulling force opposite thereto (along the BEWE ¬ supply direction axis 60) to the force measuring device 1 turn acts consequently move the two housing parts 25 and 26 from its rest position toward each other or away from each other.
In der vorteilhaften Ausführungsform der Erfindung gemäß Fi¬ gur 6 untergreift ein Teilbereich 25" des oberen starren Ge- häuseteils 25 den Schraubekopf der Schraube 7, so dass derIn the advantageous embodiment of the invention according to FIG. 6, a partial region 25 "of the upper, rigid housing part 25 engages under the screw head of the screw 7, so that the
Teilbereich 25" zwischen dem Schraubenkopf der Schraube 7 und dem unteren starren Gehäuseteil 26 angeordnet ist. In Bewe¬ gungsrichtung 60 entsteht dadurch einerseits ein Spalt a zwi¬ schen dem Schraubenkopf der Schraube 7 und dem untergreifen- den Teilbereich 25"; andererseits entsteht ein weiterer Spalt b zwischen dem untergreifenden Teilbereich 25" und dem unte¬ ren starren Gehäuseteil 26; drittens entsteht ein weiterer Spalt (nicht bezeichnet) senkrecht zur Bewegungsrichtungsach¬ se 60 zwischen der Schraube und dem Teilbereich 25" .Portion 25 "is arranged between the screw head of the screw 7 and the lower rigid housing part 26 In BEWE ¬ supply device 60 thus formed, in part, a gap a zwi¬ rule the screw head of the screw 7 and the untergreifen- the partial region 25."; On the other hand, a further gap b is created between the cross-engaging partial area 25 "and the lower rigid housing part 26, thirdly, a further gap arises Gap (not labeled) perpendicular to the direction property ¬ se 60 between the screw and the portion 25 ".
Durch diese Anordnung des Teilbereichs 25" kann die Kraft- messvorrichtung 1 in Richtung der Bewegungsrichtungsachse 60 einerseits solange mit Kraft beaufschlagt werden bis sich der Spalt b durch die Auslenkung des oberen starren Gehäuseteils 25 schließt. Dadurch wird in dieser Auslenkungsrichtung ein mechanischer Anschlag geschaffen, der eine mechanische Über- dehnung der Kraftmessvorrichtung 1 verhindert. Andererseits wird eine mechanische Überbelastung bei einer entgegengesetzt gerichteten Dehnung der Kraftmessvorrichtung 1 durch einen mechanischen Anschlag des Teilbereichs 25" auf das untere starre Gehäuseteil 26 verhindert, wobei der Spalt a geschlos- sen wird. Die hier gezeigte mechanischen Anschlagsfläche könnte ebenso auch nur aus einem Anschlagspunkt reduziert ein, falls die zweckmäßig erscheint.By virtue of this arrangement of the portion 25 ", the force measuring device 1 can be subjected to force in the direction of the movement direction axis 60 until the gap b closes due to the deflection of the upper rigid housing part 25. As a result, a mechanical stop is created in this deflection direction On the other hand, mechanical overstressing in the case of oppositely directed expansion of the force-measuring device 1 is prevented by a mechanical abutment of the portion 25 "on the lower rigid housing part 26, the gap a being closed. The mechanical stop surface shown here could also be reduced only from a stop point, if appropriate.
Die Anordnung des untergreifenden Teilbereichs 25" im Ver- hältnis zur Schraube 7 wurde nur exemplarisch anhand der im Teilschnitt der Figuren 6 und 7 dargestellten Schraube 7 er¬ läutert. Im dargestellten Beispiel der Figur 6 ist eine dazu analoge Anordnung eines weiteren Teilbereichs des oberen starren Gehäuseteils 25 und einer zweiten Schraube 7 symmet- risch zur Bewegungsrichtungsachse 60 angeordnet. Eine solch symmetrische Anordnung ist zu bevorzugen, da so auch die Druck- oder Dehnungskräfte symmetrisch auf die Kraftmessvor¬ richtung 1 wirken. Prinzipiell ist die symmetrische Anordnung folglich zu bevorzugen, allerdings könnte auch eine unsymmet- rische Anordnung gewählt werden, die funktional die gleiche Wirkung hat wie der Überlastschutz entsprechend der Figur 6. The arrangement of the under-engaging partial area 25 "in relation to the screw 7 was explained only by way of example with reference to the screw 7 shown in the partial section of FIGS 6 and 7. In the example shown in FIG. 6, an arrangement of a further partial area of the upper one is analogous thereto Housing part 25 and a second screw 7 are arranged symmetrically with respect to the movement direction axis 60. Such a symmetrical arrangement is to be preferred since the pressure or expansion forces also act symmetrically on the force measuring device 1. In principle, the symmetrical arrangement is therefore to be preferred It would also be possible to choose an asymmetrical arrangement which has the same functional effect as the overload protection according to FIG. 6.

Claims

Patentansprüche claims
1. Kraftmessvorrichtung (1)1. Force measuring device (1)
- mit einem einstückigen Gehäuse aus Metall, bestehend aus einem oberen starren Gehäuseteil (25) und einem unteren starren Gehäuseteil (26), die über U-förmige Federelemente (21, 22, 23, 24) miteinander verbunden sind und die unter Einwirken einer Kraft entlang einer Bewegungsachse (60) federnd gegeneinander bewegbar sind, wobei die Federele- mente (21, 22, 23, 24) bezüglich einer Schnittfläche (AA) parallel zur Bewegungsachse (60) symmetrisch zueinander angeordnet sind, und- With a one-piece housing made of metal, consisting of an upper rigid housing part (25) and a lower rigid housing part (26) which are connected to each other via U-shaped spring elements (21, 22, 23, 24) and under the action of a force along a movement axis (60) are resiliently movable against each other, wherein the Federele- elements (21, 22, 23, 24) with respect to a sectional area (AA) parallel to the axis of movement (60) are arranged symmetrically to each other, and
- mit einem Auslenksensor (6) zwischen den oberen und unte¬ ren starren Gehäuseteilen (25, 26) zur Erfassung deren Re- lativbewegung zueinander, dadurch gekennzeichnet, dass das Gehäuse (2) in Metal Injec- tion Molding (MIM) Technologie gefertigt ist.- With a deflection sensor (6) between the upper and lower rigid housing parts (25, 26) for detecting the relative movement to each other, characterized in that the housing (2) is manufactured in metal injection Molding (MIM) technology ,
2. Kraftmessvorrichtung (1) nach Anspruch 1, dadurch gekenn- zeichnet, dass die beiden Schenkel der Federelemente (21, 22,Second force measuring device (1) according to claim 1, characterized in that the two legs of the spring elements (21, 22,
23, 24) jeweils einen spitzen Winkel (α) einschließen.23, 24) each include an acute angle (α).
3. Kraftmessvorrichtung (1) nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Wandstärke (d) eines Federelementes (21, 22, 23, 24) ausgehend von dem oberen starren Gehäuseteil (25) zunächst abnimmt und anschließend, zum Scheitelpunkt der Federschlaufe (21, 22, 23, 24) hin wieder zunimmt.3. force measuring device (1) according to claim 1 or 2, characterized in that the wall thickness (d) of a spring element (21, 22, 23, 24), starting from the upper rigid housing part (25) initially decreases and then, to the apex of the spring loop (21, 22, 23, 24) increases again.
4. Kraftmessvorrichtung (1) nach einem der vorherigen Ansprü- che, dadurch gekennzeichnet, dass der untere starre Gehäuse¬ teil (26) mindestens eine Befestigungslasche (4) aufweist, mit welcher die Kraftmessvorrichtung (1) mit Hilfe von geeig¬ neten Befestigungsmitteln (7), vorzugsweise Schrauben (7), starr mit dem Fahrzeug-Chassis (10) verbindbar ist.4. Force measuring device (1) according to one of the preceding claims, characterized in that the lower rigid housing ¬ part (26) has at least one fastening tab (4), with which the force measuring device (1) by means of geeig¬ Neten fastening means ( 7), preferably screws (7), rigid with the vehicle chassis (10) is connectable.
5. Kraftmessvorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass das Gehäuse (2) mindestens vier U-förmige Federelemente (21, 22, 23, 24) aufweist, wobei je¬ weils zwei Federelemente (24, 21, 23, 22) in dieselbe Rich¬ tung von der Schnittfläche (AA) fortweisen.5. Force measuring device according to one of the preceding claims, characterized in that the housing (2) at least four U-shaped spring elements (21, 22, 23, 24), wherein each ¬ Weils two spring elements (24, 21, 23, 22) in the same Rich ¬ tion of the cut surface (AA) away.
6. Kraftmessvorrichtung (1) nach Anspruch 5, dadurch gekenn¬ zeichnet, dass eine Befestigungslasche (4) zwischen zwei Fe¬ derelementen (21, 24, 22, 23) angeordnet ist,6. force measuring device (1) according to claim 5, characterized gekenn¬ characterized in that a fastening tab (4) between two Fe ¬ derelementen (21, 24, 22, 23) is arranged,
7. Kraftmessvorrichtung (1) nach einem der Ansprüche 4 bis 6, dadurch gekennzeichnet, dass bei einer starren Verbindung des unteren starren Gehäuseteils (26) mit dem Fahrzeug-Chassis ein Teilbereich (25' ) des oberen starren Gehäuseteils (25) das Befestigungsmittel (7) so untergreift, dass bei Einwir¬ kung einer ausreichend großen Zugkraft auf das obere Kraft- einleitmittel (3) die Auslenkung der beiden Gehäuseteile (25, 26) zueinander begrenzt wird. 7. A force measuring device (1) according to any one of claims 4 to 6, characterized in that in a rigid connection of the lower rigid housing part (26) with the vehicle chassis, a portion (25 ') of the upper rigid housing part (25) the fastening means ( 7) so engages that when Einwir ¬ effect of a sufficiently large tensile force on the upper force introduction means (3), the deflection of the two housing parts (25, 26) is limited to each other.
EP05769891A 2004-07-23 2005-07-25 Force sensing device Withdrawn EP1771707A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004035982A DE102004035982A1 (en) 2004-07-23 2004-07-23 Force measuring device
PCT/EP2005/053619 WO2006010752A1 (en) 2004-07-23 2005-07-25 Force sensing device

Publications (1)

Publication Number Publication Date
EP1771707A1 true EP1771707A1 (en) 2007-04-11

Family

ID=34973084

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05769891A Withdrawn EP1771707A1 (en) 2004-07-23 2005-07-25 Force sensing device

Country Status (7)

Country Link
US (1) US20080083290A1 (en)
EP (1) EP1771707A1 (en)
JP (1) JP2008507687A (en)
KR (1) KR20070034130A (en)
CN (1) CN1989397A (en)
DE (1) DE102004035982A1 (en)
WO (1) WO2006010752A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7435918B2 (en) * 2005-07-15 2008-10-14 C. Rob. Hammerstein Gmbh & Co. Kg Underframe of a motor vehicle seat with weight sensors
JP5275507B1 (en) * 2012-09-25 2013-08-28 株式会社タニタ Strain body and weight measuring device
US9151659B2 (en) * 2012-09-25 2015-10-06 Tanita Corporation Flexure element where the gap between the first arm and the second arm or between an arm and the strain generating region are equal to or smaller than one half the thickness
JP5728745B2 (en) * 2013-03-27 2015-06-03 株式会社タニタ Straining body, load cell and weight measuring device
JP5557359B1 (en) * 2013-06-21 2014-07-23 株式会社タニタ Straining body, load cell and weight measuring device
US20150219489A1 (en) * 2014-02-06 2015-08-06 Delphi Technologies, Inc. Occupant detection device

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4273204A (en) * 1978-05-30 1981-06-16 The Jade Corporation Capacitive force load cell for weighing scale
CH681915A5 (en) * 1991-04-26 1993-06-15 Mettler Toledo Ag
DE59704245D1 (en) * 1996-12-04 2001-09-13 A B Elektronik Gmbh ROTARY ANGLE SENSOR
JP3683712B2 (en) * 1998-06-05 2005-08-17 タカタ株式会社 Seat weight measuring device
US6089106A (en) * 1998-09-04 2000-07-18 Breed Automotive Technology, Inc. Force sensor assembly
US6087598A (en) * 1999-02-03 2000-07-11 Trw Inc. Weight sensing apparatus for vehicle seat
US6328918B1 (en) * 1999-03-04 2001-12-11 Honeywell International Inc. Low pressure injection molding of metal and ceramic threaded components
US20030070846A1 (en) * 2001-03-26 2003-04-17 Trw Inc. Parallelogram load sensing apparatus for a seat belt webbing
DE10145370A1 (en) * 2001-09-14 2002-12-05 Siemens Ag Load reception device for automobile passenger seat has U-shaped spring element and cooperating sensor for detecting seat loading
US6916997B2 (en) * 2001-12-07 2005-07-12 Robert Bosch Corporation Weight sensors having centralized loose tolerance universal force and Mx/My moments overload stops
JP2003177052A (en) * 2001-12-13 2003-06-27 Takata Corp Apparatus for measuring sheet weight
JP2004317400A (en) * 2003-04-18 2004-11-11 Takata Corp Seat load measuring apparatus
DE102004010367A1 (en) * 2004-03-03 2005-09-29 Siemens Ag Force measuring device
US7112749B2 (en) * 2004-06-23 2006-09-26 Sensata Technologies, Inc. Sensor mounting apparatus for minimizing parasitic stress

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2006010752A1 *

Also Published As

Publication number Publication date
CN1989397A (en) 2007-06-27
KR20070034130A (en) 2007-03-27
WO2006010752A1 (en) 2006-02-02
JP2008507687A (en) 2008-03-13
DE102004035982A1 (en) 2006-03-16
US20080083290A1 (en) 2008-04-10

Similar Documents

Publication Publication Date Title
WO2006010752A1 (en) Force sensing device
DE102014103796A1 (en) System for elastically averaged alignment
DE102015105279A1 (en) System of elastically averaging assembly of components
EP2688774B1 (en) Fastening device for detachably fastening an element to a component fixed to a vehicle
WO2007090551A1 (en) Belt latch for a safety belt
DE102008020865A1 (en) Vehicle seat with a device for a vehicle seat occupancy recognition
EP1721135A1 (en) Force-sensing device
WO2010115680A1 (en) Fastening device for a cable
DE102018009432A1 (en) Energy absorbing element and method for its production
DE102011013255B4 (en) Unlocking device
DE102005005889B3 (en) Rolling guide for vehicle seat has first roller of disk which is rotatably arranged on pin whose diameter is slightly smaller than diameter of first roller and hardness of disk is larger than hardness of first roller
DE102014224444B4 (en) Impact-damping component arrangement for a motor vehicle
EP1454118B1 (en) Device for measuring a force component or a torque component
DE102009058956A1 (en) Hinge for e.g. door, in body of motor vehicle, has fixing part for fixing hinge element using connecting element and joint part for connection with another hinge element, where joint part is connected to fixing part by connecting parts
DE102008011676A1 (en) Sensor housing with fastening means
DE10216903B4 (en) Connection device for an actuating cable to a slave, in particular towing eye
EP1145924B1 (en) Height adjustment device for safety belts
EP1795743B1 (en) Edge filter
DE112019007290T5 (en) vehicle onboard camera
DE102014203847A1 (en) Arrangement for attaching a handle to an actuating lever
WO2011029441A1 (en) Force-absorbing connection and method for producing such a connection
DE102009052774B4 (en) Device for locking two components pivotable about a common joint
DE102005050787A1 (en) Fastener e.g. screw, for motor vehicle, has component arranged on horizontal axle of fastener in such a manner that component is moved in direction on axle to carry out force measurement depending on deformation and/or displacement
WO2024012621A1 (en) Lock striker for a motor vehicle door lock
EP1995574B1 (en) Weighing cell

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20061221

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE ES FR GB IT

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: CONTINENTAL AUTOMOTIVE GMBH

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20100202