DE102017127997A1 - Measuring arrangement with overload protection for measuring an axial force - Google Patents

Abstract

Measuring arrangement (200), comprising a measuring element (210) for measuring an axial force (Fa), a deformation element (220), which has a greater axial deformation path than the measuring element (210) under the application of force, and a stop element (230). The components are arranged such that the axial force (Fa) via the stop element (230), the deformation element (220) and the measuring element (210) is transferable, wherein the stop member (230) is further formed such that it is in the axial direction (A) extends along the deformation element (220) in the direction of the measuring element (210). The stop element (230) is further aligned against a stop (250) such that in the unloaded state in the axial direction (a) a gap (240) between the stop member (230) and the stopper (250) is formed, and that in a axial overload force abuts the stop element (230) against the stop (250) and thereby limits the action of the axial force (Fa) on the measuring element (210).

Description

Field of the invention

The present invention relates to a measuring arrangement with an overload protection for measuring an axial force.

Background of the invention

In a force measurement, a measuring element is generally designed so that a comparatively high force is conducted through the cross section of the measuring element component in order to achieve a significant deformation of the measuring element.

So shows DE 10 2013 222 151 A1 a measuring bearing with a sensor layer, which is arranged on a force introduction ring in close proximity to the rolling bearing. When force is applied to the rolling bearing, the force is transferred to the force introduction ring and finally to the sensor layer.

DE 10 2014 218 993 B3 also shows a rolling bearing assembly with a measuring element. Specifically, the rolling bearing assembly includes a coupling member which bundles the force acting on the rolling bearing and directs it to a reduced area of a force application member. On the force introduction element, a strain sensor device is mounted. Thus, a comparatively high force per channel is channeled to the measuring surface.

In the application, there are overload cases with a multiple of the maximum force actually to be measured. Overload situations can occur in vehicles, for example, in threshold crossings or curbs. Since the measuring element generally has a relatively small cross-section for detecting a high signal quality, the yield stress of the material is exceeded in the event of an overload and a permanent deformation on the measuring element occurs.

If, in overload situations, a multiple of the measuring range end value of the measuring element can be achieved, then the measuring element has to be made significantly stiffer again in order to avoid any permanent deformation and thus damage. To prevent such damage in case of overload, it is therefore necessary to design the measuring element so that the maximum sustainable (overload) strains can not be exceeded. However, this means that the measuring effect in the actually desired measuring range is very low and thus the quality of measurement of the resulting sensor is deteriorated.

Summary of the invention

It is therefore an object of the invention to provide a measuring arrangement with overload protection for measuring an axial force, which reduces the visible for the measuring element height of the overload force.

This object is achieved by a measuring arrangement with a measuring element for measuring an axial force, a deformation element and a stop element. The deformation element has a larger axial deformation path under force than the measuring element.

The components are arranged such that the axial force on the stop element, the deformation element and the measuring element is transferable, wherein the stop element is further formed such that it extends in the axial direction of the deformation element in the direction of the measuring element.

The stop element is further aligned against a stop such that in the unloaded state, a gap between the stop element and the stop is formed in the axial direction, and that stops at an axial overload load, the stop element against the stop and thereby limits the action of the axial force on the measuring element ,

In other words, the deformation element is arranged in series with the measuring element, wherein the stop element and the deformation element can be subjected to an applied force, and wherein the stop element extends laterally along the deformation element or as a passage, for example as a through hole, through the deformation element , and can strike against a stop to limit an application of force to the measuring element.

The deformation element therefore has a lower rigidity, for example a larger factor, than the measuring element 10 , in the direction of the axial force. As a result, the deformation element is axially significantly more compressed than the measuring element, whereby the gap is closed in case of overload. Due to the large Axialwegunterschiede between the measuring element and the deformation element, the gap can be designed to be made robust and changes in the stiffness of the deformation element play only a minor role.

Thus, there is an effective overload protection, which is at a force application which is greater than the desired measuring range, but significantly less than the overload force engages.

In one embodiment, the measuring arrangement is annular or rectangular. It is therefore possible to design the measuring arrangement according to the invention geometrically differently. In one embodiment, the measuring element is a measuring ring.

The measuring element may be formed on the basis of a strain measurement, an inverse magnetostrictive measurement or an eddy current distance measurement. With these technologies, strains in the micrometer range can be detected, which makes it possible to measure very small paths in the direction of force. As a strain measurement, for example, a direct coating, as known from the applicant under the name Sensotect, in question.

In one embodiment, the measuring arrangement comprises a support element which is arranged between the deformation element and the measuring element. The support element may be a support disk or a support ring. The support element ensures a homogeneous introduction of force into the measuring element.

In one embodiment, the deformation element is formed from an elastomer.

In a further embodiment, the deformation element is connected to the measuring element and / or the stop element and / or the support element or integrally formed. The deformation element may be formed, for example, as an (on) injection-molded elastomer on the measuring element and / or the stop element and / or the support element.

In a further embodiment, the stop is formed by a starting element, in particular a thrust washer or a thrust ring. The starting element likewise ensures a homogeneous introduction of force into the measuring element.

The surfaces of the measuring element and its mating surfaces, for example the surfaces of the starting element or of the support element, may be provided with a friction-reducing element, for example a tribological coating or a friction-reducing material, such as grease. Thus, the friction between the measuring element and the contacting components, via which the force is introduced, is reduced. The reduction in friction has the consequence that the signal detected via the measuring element has a lower hysteresis. Such a hysteresis arises from the fact that the measuring element moves under force on its mating surfaces, for example by widening. If this movement is hindered by friction, a hysteresis is created.

In one embodiment, the starting element is part of a surrounding structure, for example part of a drawbar of a drawbar of a trailer. The measuring element is thus arranged directly on the surrounding structure. This has the advantage that a component is saved and the measuring arrangement can be made compact. For example, then a separate thrust washer or a separate thrust ring is not required.

In one embodiment, the stop element is part of the surrounding construction, in particular a housing of a drawbar of a trailer. This has the advantage that a component which takes over the function of the stop element, is saved and the measuring arrangement can be made compact.

In one embodiment, the stop element extends in the axial direction radially outward from the deformation element. Thus, a large support surface can be achieved with the same radial space.

In one embodiment, the stop element extends in the axial direction radially inward of the deformation element. This allows a simple external contacting, for example via a cable outlet, of the measuring element.

In one embodiment, the stop element extends in the axial direction radially inward and radially outward from the deformation element. Due to the two-sided support increases the support surface and thus the stability. The stop element is still under a lower deformation.

In one embodiment, the measuring element is U-shaped, wherein the U-shape opens in the axial direction. Due to the U-shaped configuration, more force per cross-sectional area is introduced into the measuring element.

In one embodiment, the deformation element has at least one through hole, wherein the stop element comprises at least one stop pin. The stopper pin is feasible through the through hole. This embodiment has the advantage that in the radial direction no space for the arrangement of the stop element is required. Thus, it is easily applicable even in confined spaces.

In a development of the preceding embodiment, the through-hole is also formed through the measuring element. In other words, the stop pin extends through the deformation element and the measuring element and can strike a stop in the event of an overload. In this embodiment, the measuring element and the stop are arranged one behind the other in the force flow of the axial force.

In one embodiment, the measuring element and the stop are arranged such that they are not in the axial direction in succession in the force flow of the axial force. Thus, the measuring element and the stop may be formed as a one-piece component, in particular as a ring, which has a measuring range of the measuring element and a stop region of the stop element in sections. In other words, the stopper member can be supported on non-sensed portions of the one-piece component. In this case, it is also possible to form the measuring region of the measuring element, that is to say the sensed section of the one-piece component, in a U-shape and optionally with a force introduction pin in order to achieve more force per cross-sectional area.

Likewise, a non-uniform or one-piece component is conceivable in which the measuring element and the stop continue to be in the axial direction not consecutively in the force flow of the axial force. Thus, the measuring element and the stopper may be formed as individual segments.

An advantage of the arrangement in which the measuring element and the stop in the axial direction are not consecutively in the force flow of the axial force, is that a small space in the radial direction is required because the stop element does not have to be guided past the side of the measuring element. Also with respect to the embodiment with a penetration in the measuring element, this embodiment has an advantage, namely that a larger contact surface for the stop element can be achieved.

In a further embodiment, the deformation element and / or the stop element are segmented. This allows the stop element to extend along the deformation element in the direction of the abutment between two segments of the deformation element. The embodiment has similar advantages for the required installation space as described above.

Further advantages, features and details of the invention will become apparent from the embodiments described below and with reference to the drawings.

list of figures

• 1 eine Überblicksdarstellung einer Messanordnung in einer Umgebungskonstruktion mit einem Zugrohr 152 und einem Gehäuse 132;
• 2 eine Überblicksdarstellung einer Messanordnung in einer Umgebungskonstruktion mit einem Zugrohr 252 und einem Gehäuse 232 mit einem separaten Anlaufring 250 und einem separaten Anschlagselement 230;
• 3a, 3b eine ringförmige Messanordnung in zwei unterschiedlichen Perspektivdarstellungen;
• 4 ein Ausführungsbeispiel einer weiteren ringförmigen Messanordnung;
• 5 ein Ausführungsbeispiel einer rechteckigen Messanordnung;
• 6 ein Ausführungsbeispiel einer weiteren ringförmigen Messanordnung mit einem u-förmigen Messring 610;
• 7a, 7b ein Ausführungsbeispiel einer weiteren ringförmigen Messanordnung mit Durchganglöchern 770 und Anschlagsstiften 780 in einer Perspektivdarstellung in 7a und einer Explosionsdarstellung in 7b;
• 8 ein Ausführungsbeispiel einer Messanordnung mit einem kompakten Design des Messelements 810 und dem Anschlag 850, sowie segmentiertem Deformationselement 820; und
• 9 ein Ausführungsbeispiel einer Messanordnung mit Merkmalen aus 7a, 7b und 8.

Hereinafter, embodiments of the invention will be illustrated with reference to figures. Show it:

• 1 an overview of a measuring device in a surrounding construction with a draft tube 152 and a housing 132 ;
• 2 an overview of a measuring device in a surrounding construction with a draft tube 252 and a housing 232 with a separate stop ring 250 and a separate stop element 230 ;
• 3a . 3b an annular measuring arrangement in two different perspective views;
• 4 an embodiment of another annular measuring arrangement;
• 5 an embodiment of a rectangular measuring arrangement;
• 6 an embodiment of another annular measuring arrangement with a U-shaped measuring ring 610 ;
• 7a . 7b an embodiment of a further annular measuring arrangement with through holes 770 and stop pins 780 in a perspective view in 7a and an exploded view in FIG 7b ;
• 8th an embodiment of a measuring arrangement with a compact design of the measuring element 810 and the stop 850 , as well as segmented deformation element 820 ; and
• 9 an embodiment of a measuring arrangement with features 7a . 7b and 8th ,

Detailed description of the drawings

2 shows the measuring arrangement 200 in a surrounding construction. The surrounding construction includes the drawbar 252 as well as the housing 232 a drawbar. The drawbar can be part of a trailer. On the surrounding structure can be in the axial direction a the axial force fa Act. The measuring arrangement 200 is in engagement with the drawbar 252 and the housing 232 arranged such that they in the direction of force of the axial force fa lies. The measuring arrangement comprises the L-shaped stop element 230 , the deformation element 220 , the support element 260 , the measuring element 210 and the stop 250 namely a starting element. The support element 260 and the starting element are respectively from both sides of the measuring element 210 flat with the measuring element 210 arranged so that the axial force fa homogeneous in the measuring element 210 can be initiated. The L-shaped stop element 230 extends laterally on the deformation element 220 , the support element 260 and the measuring element 210 over and is against the stop 250 , namely the starting element, aligned. Between the stop 250 and the L-shaped stopper member 230 is in the axially unloaded state of the gap 240 trained as in 2 shown. At an axial overload force strikes the stop element 230 against the attack 250 ,

3a and 3b show the annular measuring arrangement 300 , The measuring arrangement 300 is constructed like the measuring arrangement 200 out 2 , The 3a . 3b show, among other things, the measuring element 310 as a measuring ring, the annular deformation element 320 , the ring and L-shaped stop element 330 radially outside, the gap 340 , the stop 350 as a stop ring, and the support element 360 as a support ring. In contrast to the measuring arrangement 200 out 2 is the measuring arrangement 300 in 3 clearly ring-shaped. The measuring arrangement 200 in 2 may also only partially on the circumference of the drawbar 252 extend the surrounding construction.

1 shows the measuring arrangement 100 in a surrounding construction. The surrounding construction includes the drawbar 152 and the case 132 , In contrast to 2 form in 1 the draft tube 152 the stop 150 and the case 132 the stop element 130 , Thus, the surrounding construction is in 1 partly with the measuring arrangement 100 integrated. Compared to the measuring arrangement 200 out 2 fewer individual components are required.

4 shows the measuring arrangement 400 , measuring arrangement 400 is like measuring arrangement 300 out 3a . 3b ring-shaped and also know the components measuring element 410 , Deformation element 420 , Stop element 430 , Attack 450 , Support element 460 and the gap 440 on. The L-shaped stop element 430 However, it is arranged so that it extends radially inward.

5 shows measuring arrangement 500 , measuring arrangement 500 is rectangular. As a further difference to the measuring arrangements 100 . 200 . 300 . 400 out 1 . 2 . 3a . 3b . 4 is the deformation element 520 directly on the measuring element 510 arranged. A support element between the deformation element 520 and the measuring element 510 is not present.

6 shows measuring arrangement 600 , measuring arrangement 600 is annular. The stop element 630 and the measuring element 610 are U-shaped. The stop element 630 thus extends both radially inward and radially outward in the direction of the stop 650 ,

7a . 7b show measuring arrangement 700 in a perspective view and exploded view. measuring arrangement 700 is annular. The deformation element 720 , the support element 760 and the measuring element 710 have through holes 770 on. The stop element 730 has the stop pins 780 on getting into the through holes 770 extend and with an axial overload against the stop 750 can strike.

8th shows measuring arrangement 800 , measuring arrangement 800 is annular. The U-shaped measuring element 810 with a force introduction pin and the stop 850 are formed as a common ring. The ring thus has sections a measuring range for the measuring element 810 and a stop area for the stop 850 on. Next is deformation element 820 segmented so that the stop element 830 between the segments can attack and against the stop 850 is aligned.

9 shows measuring arrangement 900 which is annular. The U-shaped measuring element 910 with a force introduction pin and the stop 950 are like in 8th designed as a common ring. The deformation element 920 and the support element 960 have through holes 970 on, in which stop pins of the stop element 930 extend. In contrast to the measuring arrangement 700 in 7a . 7b are no through holes in the measuring element 910 required because the stop 950 and the measuring element 910 side by side, and not consecutively in the force flow of the axial force fa , are located.

LIST OF REFERENCE NUMBERS

100, 200, 300, 400, 500, 600, 700, 800, 900

measuring arrangement

110, 210, 310, 410, 510, 610, 710, 810, 910

measuring element

120, 220, 320, 420, 520, 620, 720, 820, 920

deformation element

130, 230, 330, 430, 530, 630, 730, 830, 930

stop element

132.232

casing

140, 240, 340, 440, 540, 640, 740, 840, 940

gap

150, 250, 350, 450, 550, 650, 750, 850, 950

attack

152.252

draw tube

160, 260, 360, 460, 660, 760, 860, 960

support element

770.970

Through Hole

780, 980

stop pin

a

axial direction

fa

Axial force

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013222151 A1 [0003]
• DE 102014218993 B3 [0004]

Claims (14)

Measuring arrangement (100, 200, 300, 400, 500, 600, 700, 800, 900), comprising the following components: a measuring element (110, 210, 310, 410, 510, 610, 710, 810, 910) for measuring an axial force (Fa), a deformation element (120, 220, 320, 420, 520, 620, 720, 820, 920) which, under the application of force, has a larger axial deformation path than the measuring element (110, 210, 310, 410, 510, 610, 710, 810, 910), and - A stop element (130, 230, 330, 430, 530, 630, 730, 830, 930), wherein the components are arranged such that the axial force (Fa) via the stop element (130, 230, 330, 430, 530, 630, 730, 830, 930), the deformation element (120, 220, 320, 420, 520, 620, 720, 820, 920) and the measuring element (110, 210, 310, 410, 510, 610, 710, 810, 910) is transferable, wherein the abutment element (130, 230, 330, 430, 530, 630, 730, 830, 930) is further configured to extend in the axial direction (a) on the deformation element (120, 220, 320, 420, 520). 620, 720, 820, 920) extends in the direction of the measuring element (110, 210, 310, 410, 510, 610, 710, 810, 910), and wherein the abutment member (130, 230, 330, 430, 530, 630, 730, 830, 930) is alignable against a stop (150, 250, 350, 450, 550, 650, 750, 850, 950), that in the unloaded state in the axial direction (a) a gap (140, 240, 340, 440, 540, 640, 740, 840, 940) between the stop element (130, 230, 330, 430, 530, 630, 730, 830 , 930) and the stop (150, 250, 350, 450, 550, 650, 750, 850, 950) is formed, and that at an axial overload force the abutment member (130, 230, 330, 430, 530, 630, 730, 830, 930) abuts against the stop (150, 250, 350, 450, 550, 650, 750, 850, 950) and thereby limits the action of the axial force (Fa) on the measuring element (110, 210, 310, 410, 510, 610, 710, 810, 910). Measuring arrangement after Claim 1 wherein the stop (150, 250, 350, 450, 550, 650, 750, 850, 950) is formed by a starting element, in particular a thrust washer or a stop ring. Measuring arrangement after Claim 2 wherein the run-up element (150) is part of a surrounding structure, in particular a drawbar (152) of a drawbar of a trailer. Measuring arrangement according to one of Claims 1 to 3 in that the stop element (130) is part of the surrounding construction, in particular of a housing (132) of a drawbar of a trailer. Measuring arrangement according to one of Claims 1 to 4 further comprising a support element (160, 260, 360, 460, 660, 760, 860, 960), in particular a support disk or a support ring, which is located between deformation element (120, 220, 320, 420, 620, 720, 820, 920) and measuring element (110, 210, 310, 410, 610, 710, 810, 910) is arranged. Measuring arrangement according to one of Claims 1 to 5 , wherein the measuring arrangement is annular (100, 200, 300, 400, 600, 700, 800, 900) or rectangular (500) is formed. Measuring arrangement (100, 200, 300) after Claim 6 in that the stop element (130, 230, 330) extends radially outward from the deformation element (120, 220, 320) in the axial direction (a). Measuring arrangement (400) according to Claim 6 or 7 in that the stop element (430) extends in the axial direction (a) radially inward from the deformation element (420). Measuring arrangement according to one of Claims 1 to 8th wherein the measuring element (610) is U-shaped, and the U-shape opens in the axial direction (a). Measuring arrangement according to one of Claims 1 to 9 wherein the deformation member (920) has at least one through hole (970), the stopper member (930) having at least one stopper pin (980), and wherein the stopper pin (980) is passable through the through hole (970). Measuring arrangement after Claim 10 wherein the through-hole (770) is further formed through the sensing element (710). Measuring arrangement (800, 900) according to one of Claims 1 to 11 , wherein the measuring element (810, 910) and the stop (850, 950) are arranged such that they are not in the axial direction (a) in succession in the force flow of the axial force (Fa). Measuring arrangement after Claim 12 , Wherein the measuring element (810, 910) and the stop (850, 950) as a one-piece component, in particular as a ring, is formed, the sections a measuring range (810, 910) and a stop region (850, 950). Measuring arrangement according to one of Claim 1 to 13 wherein the deformation element (820) and / or the stop element (830) are segmented.

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