EP0919257A2 - Clamping device for a boom system - Google Patents

Abstract

The clamp for the jib-arm system consists of a statically set mounting (Ar1,A11) with meters (11Ar,11Al, 11B) for measuring individual bearing forces. A base element (8) of the jib-arm system is detachably fixed to the support element (5) by means of the mounting consisting of at least three separate bearings which are positioned in relation to their center bearing points symmetrically with the plane of symmetry in the longitudinal direction of the base element.

Description

The invention relates to a device for clamping a boom system of a swiveling, tilting and telescopic Tool over a support element on one Bogie of a vehicle, such as an emergency vehicle the fire department or the like, with a measuring device in the clamping area for the current determination of the load of the boom system.

In fire brigade vehicles or the like the boom system is clamped, in particular a ladder set in general on a so-called Bogie. By means of this attachment, the erection should and tilting the boom system. Usually the attachment to the turret is not direct about a basic element of the ladder set, but there are for this purpose, floating support elements are provided on the turret, which form the bogie with the turret. Because of the U-shaped cross-sectional profile of the conductor elements of the Ladder set is a connection of the same to the support element only in the outer area of the outer conductor element, So the base element is possible to get inside not to obstruct the ladder set and so on further conductor elements within the U-shaped base element to be able to store.

To raise and tilt the boom system ensure, takes over the mentioned support element both the storage of the righting axis and the storage of the lower part of the ladder and that of the hydraulic acting upright cylinder or a pair of upright cylinders. In terms of its external dimensions the carrier element in the longitudinal direction of the boom system designed such that it is the same as a bending beam Strength comes close to the swivel bending area to be able to optimize, especially what the lowering of the Boom system below the horizontal concerns. The Width of the support element is due to the width of the outrigger boom system, i.e. its ladder parts, by the total width of the construction so given to minimize on the bogie. Are not additional Facilities such as terrain compensation provided, so are the base element of the boom system and the support element generally directly with one another screwed, creating a detachable connection between the is given to both elements. Except for simple screw connections are also expansion screw connections as releasable Connection between base element and carrier element known. This is supposed to be the narrowest possible storage of the boom system, on the other hand this makes the connection through simple different Elements realized.

It is also known to determine the current stress on the Cantilever system in order to ensure component safety to rate. For this purpose, a measuring system is known in which the bending stress of the boom system in / on the Clamping point is measured. Here is the bottom one Bearing part in a turntable system on the support element, so the carriage, rotatably and is at the end the lower part of the ladder is held by a spring system. As a measure of the current bending stress in the clamping point the current distance measurement is carried out by the boom with knowledge of the error rate.

Furthermore, systems are known in which metrological trained bending beam parallel to the lower part of the ladder, that is, the base element is arranged to deform it proportionally. This is done using simple limit switch up to the provided strain gauges.

A disadvantage of all these measuring systems, however, is that they only record the bending stress of the boom. Longitudinal forces, transverse forces and torsional loads on the Boom systems, however, are still unknown.

Boom systems in the form of turntable ladders now work by increasing the basket capacity (from 2 to 3 man baskets), the provision of launcher inserts etc. the loads no longer in the primarily vertical of the U-shaped profile of the ladder elements, but outside and, among other things, cause non-negligible Torsional moments. Depending on the size of the Raising angle of the aerial ladder system essentially the connecting elements of each Claim conductor elements with each other, d. H. the Ropes and / or the hydraulic cylinders up to storage in the clamping point. For this reason it is over safety aspects necessary, well also due to the lateral force or the moment, for example to know of a "kick-off" in order to reach a limit value the initiated movements of the boom system to be able to stop both the boom as well as involved persons are not harmed. A but such is by means of the known, preceding explained devices not possible.

For this reason, the object of the invention Basically, a device of the type mentioned to further develop that at the clamping point reliable interception of the constraining forces and moments and a reliable detection of the same is possible.

According to the invention the object is achieved by a Device of the type mentioned above solved that the clamping of the boom system by a static certain storage with measuring devices for measurement of the individual bearing forces is formed. So it is as Fixing a boom system a statically determined Storage with the possibility of measuring the individual Bearing forces are provided in this clamping.

Those problems or Systems called, their solution clear and complete emerges from the static equilibrium conditions. This is always the case when the kinematic Bonds of the material system under consideration, So here the boom system, at the clamping point are not more numerous than the degrees of freedom of the same, however free moving system. Then namely the number of the constraining forces and moments searched for, the as a result of ties occur no larger than that Number of equilibrium conditions, so this one uniquely solvable system of determination equations for represent the unknown constraints. Corresponding can then be easily also by means of the measuring devices determine the individual bearing forces that occur.

It is known that in one-sided clamping Beam, here the boom system at the clamping point, in its cutting plane perpendicular to the longitudinal axis generally three forces and three moments in one Cartesian coordinate system. These possible Cutting forces in this area result on the one hand from the external and internal forces of the free cantilever element (s) elements as well as the support reactions in the clamping point. Through the configuration according to the invention the storage is as statically determined storage then the clamping point will be able to handle these three forces and to capture moments so as to balance conditions to meet. Furthermore, by the measuring devices also the ability to capture this Forces and moments.

The design according to the invention also provides for this ensured that the measuring devices with the clamping be moved and so all three attacking directly Can capture forces and moments in the clamping. In this way, those acting on the boom system external and internal forces and moments individually classified and evaluated. Because with a boom system of the mentioned embodiment, the carrier element of the Mount is erected and the base element and the support element connecting storage "rigid" between this is arranged, but moves with the clamping are no additional corrective measures due to changed kinematic conditions of the Erection system, for example the erection cylinder etc. required.

In a preferred embodiment it is provided that the Base element of the boom system can be detached via the bearing is fixed on the support element.

In a further preferred embodiment it is provided that the number of individual bearings is chosen so that a statically determined storage of the entire system, however, the number of individual warehouses is minimal. This Requirement is met in that the storage by at least three individual bearings are formed. Preferably are the individual warehouses with regard to their storage centers symmetrical to the plane of symmetry in the longitudinal direction of the base element of the boom system. The dimensions of this bearing arrangement are a matter of course from the dimensions of the end of the boom, that is Base element and / or the width or length of the carrier element certainly. This makes it possible to simple Way to ensure a clear storage and the to meet measurement requirements for this storage.

The individual bearings are particularly advantageous for projection on the support element in the apices of an isosceles Triangular. To the lowest possible height to realize, it is preferably provided that the individual bearings in a common plane between the base element of the boom system and the support element are. But it can also be at least one of the individual bearings shifted vertically compared to the others be.

To measure the forces and moments that occur reliably record in the area of the entire storage To be able to, there are measuring elements in every single bearing intended. In a preferred embodiment, the Measuring elements each one with its ends in a bore of a support component fixed on the support element mounted load measuring pin, its middle Area over an eye bed with one on the base element specified component for radial power transmission in Connection is established. Such individual bearings and measuring elements can be easily between at the interface level realize the base element and the support element. Of the Load measuring pin not only serves as part of the Measuring element, but at the same time as a component the individual storage. This embodiment has seen kinematically two relative degrees of freedom, namely one axial displacement and a rotation around the cylinder or Pin axis. The power transmission from the base element connected component on the with the support member connected component is only possible radially. Preferably the load measuring pin is designed as a hollow cylinder the inside of which measured the deformation (by bending) can be. Controlled deformation of the axis strain gauges are strain gauges provided on the inside of the bolts. Such Strain gauges (DMS) record depending on the version the bending stress also in two vertical directions the bolt axis, which then creates two forces as a measurement result. The respective components of the Forces determined by measurement technology are due to the arrangement of the load measuring pin. With these possibilities of uniaxial or biaxial force determination combinations of a statically determined storage for the clamping point in a cutting plane between Realize base element and support element.

If general radial forces are of interest, this is Execution of the bearing with measuring elements as biaxial Measuring system provided, the coordinate of this radial load plane is coordinated with the measuring system. The strain gauges are for accurate and error-free recording each in the area of the load center of the load measuring pin arranged.

A device for processing the Measured values provided, as from the strain gauges measured moments and forces according to the equilibrium conditions to be taken into account and to be compared with permissible values Values must be determined. To when the limit is reached all initiated movements of the boom system being able to slow down or stop is preferred one that can be activated when the permissible measured value is exceeded Alarm unit provided, which is in training can be an acoustic alarm unit. Furthermore, at least one display device is for output of the measured values determined and thus for information of the provided by the respective operator.

To follow before bolt rotation and axial migration Protecting from friction is a rotation lock in advanced training provided for the load measuring pin. Furthermore are Spacer elements for axial adjustment, i.e. calibration intended. Furthermore, the individual warehouse can be provided with thrust washers to the possible bearing play to eliminate the bearings. This results in an almost play-free guidance of the boom system as well a relief of the load measuring pin from forces resulting from Moments around axes of no interest result.

To compensate for misalignments between the Drilling the eye bearing and the holes in the support element to worry, which leads to tension of the load measuring pin and can lead to measurement errors, the Single bearing a spherical bearing, that is, a spherical bearing in the eye bed, on to relative movements, deformations and to record flight deviations so that the kinematic Tolerance remains intact.

If each individual bearing is provided with a ball segment, then every single bearing is kinematically compatible against angular errors and / or misalignments, because a single spatial shift at a storage location relative to the other corresponding rotations around the Triangle sides as well as displacements according to the Degrees of freedom in the individual bearings.

Overall, such a device is created, which in is capable of statically determining equilibrium conditions to fulfill and the occurring forces and moments also to be measured.

Fig. 1

eine perspektivische Ansicht eines Einsatzfahrzeuges der Feuerwehr mit einer Drehleiter als Auslegersystem;

Fig. 2

eine erste Ausführungsform einer erfindungsgemäßen Lagerung zwischen dem untersten Leiterteil und der Lafette;

Fig. 3

eine zweite Ausführungsform der erfindungsgemäßen Lagerung;

Fig. 4

einen Längsschnitt durch ein Einzellager;

Fig. 5

eine Teilansicht eines Einzellagers im Bereich der Lastmittelebene und

Fig. 6

eine schematische Darstellung zur Erläuterung möglicher Lageranordnungen.

Further advantages and features of the invention result from the claims and from the following description in which exemplary embodiments are explained in detail with reference to the drawing. It shows:

Fig. 1

a perspective view of a fire engine with a turntable ladder as a boom system;

Fig. 2

a first embodiment of a storage according to the invention between the lowermost conductor part and the carriage;

Fig. 3

a second embodiment of the storage according to the invention;

Fig. 4

a longitudinal section through a single warehouse;

Fig. 5

a partial view of a single warehouse in the area of the load medium level and

Fig. 6

a schematic representation to explain possible bearing arrangements.

The emergency vehicle 1 shown in FIG. 1 has known manner, a vehicle chassis 2 with front wheels 3a and rear wheels 3b and one of the vehicle chassis 2 supported vehicle body 4 in the form of a bogie from a turret 4a and a support member 5, the for swiveling with inclination to the horizontal or is articulated relative to the underground. The Carrier element 5 carries a boom system 6 of several displaceable against each other and thereby a variable in length Ladder sections forming supporting beams. To the Swiveling of the carrier element 5 on the bogie 4 engages on the underside of the carrier element 5 an erection cylinder 7, which has its other end at the base of the turret 4 is set.

As can be seen in particular from FIGS. 2 and 3, serves the carrier element 5 as a receptacle for the lower or outer conductor part 8, called base element for short, the Boom system 6. This is the respective basic element 8 on the support element 5 via a statically determined storage clamped, which in the illustrated embodiment 2 and 3 each by three individual bearings B1, Ar1, Al1 or B2, Ar2 and Al2 is formed. 6 these bearings are shown schematically and by Al, Ar as well as B * and B. 2 and 3 also to the three individual bearings B1, Ar1, Al1 are located or B2, Ar2 and Al2 in one plane between the base element 8 and the carrier element 5. The same applies to the individual bearings Al, Ar and B in Fig. 6, while the bearing B * vertical by the height c compared to the bearings Al and Ar is moved out of the plane.

As shown in FIG. 6 in particular, the individual bearings A1, Ar and B or B * in the apex of an isosceles Triangle with the sides b and a or a2. The amount of triangle formed by the sides b and a becomes a1 designated.

Furthermore, a Cartesian coordinate system is in Fig. 6 drawn, the axes or coordinates with x, y and z are designated. Such a Cartesian Coordinate system is used in analytical processes Breakdown of force and moment vectors is common. The y-axis represents in the illustrated embodiment Bisector of side b, on which then that too Camp B is located. When compared with FIGS. 2 and 3 shows themselves that this y-axis of the plane of symmetry of the carrier element and the base element of the boom system in the longitudinal direction of the boom. The origin the Cartesian coordinate system is in the middle on the connecting line b between the two on the X-axis arranged single bearings Al and Ar.

As can be seen in FIGS. 2 and 3, the bearing arrangement is of the three individual bearings selected so that they are in one Connection level between the bottom of the base element 8 and the top of the carrier element 5 are. The dimensions of the bearing arrangement are due to the Dimensions of the characterized by the base element 8 Boom end and the width or length of the support element certainly. As the figures show, it is Base element 8 each on the underside of its longitudinal strips a and b via the individual bearings Ar2 and Al2 or Ar1, Al1 clamped on the support element 5, while the bearing B2 or B1 set on the underside of a rung 10 is. The individual warehouse B1 or B2 is located at the end of each boom 6.

4 with reference to a Camp B1 explains the structure of the individual warehouse in more detail. The bearing B1 has one in the form of a hollow cylinder trained load pin 11B, with its Bolt ends 12a, 12b each in a bearing bore 13a, 13b of a carrier component 14 is mounted. A backup 15 protects the load pin 11B from rotation and axial Emigration due to friction. Through spacer elements 16 there is an axial adjustment in the z direction drawn load and measurement level LM and the load elements (Calibration).

In the middle of the load measuring pin 11B is an eye bearing 17 a cantilever part 18 firmly connected to the latter guided radially by the load measuring pin 11B. That way made a detachable connection. A shift is only in the axial direction, i.e. along the bolt axis S possible. Furthermore, the power transmission from the component 18 on the component 14 only radially. To compensate of misalignments between the outer bore 19 and the bores 13a, 13b of the carrier component 14, which to Tension of the load measuring pin 11B and thus to measurement errors can lead are spherical in the outer bore 19 Bearing 20 (spherical bearing) with an inner spherical Tread 20a and an outer bearing bush surrounding it 20b used; the latter is in the axial direction of the Load measuring bolt through the eye bearing 17 on the one hand and on the other hand, a fuse 20c, such as a Snap rings, secured. 5 can be seen this spherical bearing 20 via a sliding material 21 on the Outside of the load pin 11B so as to certain limits misalignments by an angle of rotation δ to be able to compensate kinematically. 5 shows hereby the measuring plane M compared to the real load plane LM, which passes through the load center L, shifted by δ. If you compare this to the Cartesian coordinate system, is such an axial displacement in the y direction approved and a spatial misalignment possible. The due to displacements and deformations of the adjacent construction as well as manufacturing inaccuracies Angle and position changes are due to this storage concept Kinematically compatible. Then it will be at such shifts and misalignments over the Load measuring pin 11B measured the force in the z-direction with multiplied by a constant factor a and then by compared to an allowable limit. When the Limit value or its exceeding are then all initiated movements of the boom 6 slowed or stopped.

To measure the occurring forces are in every warehouse Measuring elements provided in the form of strain gauges. As shown in Fig. 4, there is on the inside of the load pin 11B parallel to the pin axis S in the area of the Longitudinal center L a strain gauge 22a in the z direction and a strain gauge 22b in the x direction arranged. Through this two-axis measuring system can the components of the attacking force F in x and z direction can be reliably detected. Such strain gauges 22a, 22b mostly consist of a carrier made of paper or plastic, on which a resistance wire applied or the type of printed circuit is made. The resistance of such a strain gauge changes with its length and becomes out for this reason for static and dynamic measurements used. With such strain gauges 22a, 22b are stretched and compressed at elastically deformable Bodies, here the load measuring bolts 11B, forces, Pressures, tensions, moments and accelerations or the like measured. The strain gauges are for this purpose 22a, 22b on the deforming load measuring pin 11B for example, applied by gluing.

Should only bending moment loads over the load measuring pin and the strain gauges are detected a uniaxial measuring system in the bearing 11B is sufficient.

We refer below to FIGS. 2 and 3, in those embodiments for two different Bearing arrangements are shown.

In the embodiment shown in Fig. 2 is the bearing arrangement with respect to the individual pin axes symmetrical to the plane of symmetry in the longitudinal direction of the Boom 6 or base element 8 (y, z plane in Fig. 6). The axes of the load measuring bolts 11Ar and 11Al are in place perpendicular to this plane and cursed. they form together an axis of rotation that is perpendicular to the y, z plane stands. The pin axis of the load pin 11B is in this plane of symmetry and is perpendicular to the z, x plane (see also Fig. 6). Camp B1 is mainly on End of the base element 8 and thus the boom 6 is arranged. Through this bearing arrangement changes due to deformation of the individual bearing points balanced without tension from external load spectra become.

The forces determined by means of these individual bearings Ar1, Al1, B1 then serve subsequently to determine the six measured variables (forces and moments) which represent the current stress. The formulas used for this are shown below: FQx = - FBx <FQx allow FNy = - (FAry + FAly) <FNy allow FQz = - (FArz + FAlz) - FBz <FQz allow Mb = a1 FBz <Mb allow Mt = b / 2 (FArz - FAlz) <Mt allow Mz = b / 2 (FAly - FAry) - a1 FBx <Mz allow

The forces and moments determined must then be lower as allowable values; otherwise there will be a slowdown or stopping the extension and pivoting, Raising and lowering all intended automatic and manually initiated movements such as extending and Swiveling, lifting and lowering of the boom system, causes, including automatic terrain compensation.

In the embodiment shown in Fig. 3, the Bearing arrangement not with respect to the individual pin axes symmetrical to the x, z plane, i.e. the plane of symmetry in Longitudinal direction of the boom 6 or base element 8. Die Axis 11Ar of the single bearing Ar2 is parallel to this Level, the axis of the load measuring pin 11Al of the single bearing Al2 perpendicular to this plane. The distances to the centers the force transmission in the two load measuring bolts 11Ar and 11A1 are again symmetrical to the y-, z plane and aligned. They are also perpendicular to the y-, z-plane arranged. The arrangement is interchangeable. The Pin axis of the load measuring pin 11B of the single bearing B2 lies in the plane of symmetry and is perpendicular to the z-, x plane. Again, it is primarily at the end of the boom 6 or base element 8 arranged.

Are all the sizes listed above metrologically this bearing arrangement is more advantageous, as they are free of internal tension in the bearings with each other due to the deformation of the boom end and carrier element. This bearing arrangement is corresponding also technically free of errors on it are based.

Another advantage of this bearing arrangement is that the individual rotations and displacements are the least if the ratio a1 / b> 2 , especially a1 / b = 3 is (see Fig. 6). a1 is the height of the isosceles triangle on which the individual bearings are located, b is the distance between the individual bearings Al2 and Ar2. The measurement errors due to off-center, radial loading due to the degrees of freedom in the individual bearings themselves are thus still minimized. The same applies to twists (angular errors). The evaluation of the six measured variables is corresponding FQx = - (FArx + FBx) <FQx allow FNy = - FAly <FNy allow FQz = - (FArz + FAlz) - FBz <FQz allow Mb = a1 FBz <Mb allow Mt = b / 2 (FArz - FAlz) <Mt allow Mz = b / 2 FAly - FBx a1 <Mz allow

A further embodiment variant can be seen in FIG. 6, where the single warehouse B * is not on one level Bearings Ar and Al lies, but in the vertical around the Distance c is shifted. This only changes the evaluation of the moment balance for the torsional moments Ar by the additional operation + (c * Bx).

Claims (18)

Device for clamping a boom system of a swiveling, tilting and telescopic tool via a support element on a bogie a vehicle, such as an emergency vehicle Fire brigade or the like, with a measuring device in the clamping area for the current determination of the Stress on the boom system, characterized in that that the clamping of the boom system (6) by a statically determined bearing (Ar1, Al1, B1, Ar2, Al2, B2, Ar, Al, B, B *) with measuring devices (11Ar, 11Al, 11B, 22a, 22b) for measurement of the individual bearing forces is formed. Device according to claim 1, characterized in that a base element (8) of the boom system (6) about storage (Ar1, Al1, B1, Ar2, Al2, B2, Ar, Al, B, B *) releasably attached to the carrier element (5) is. Device according to claim 1 or 2, characterized in that that the storage (Ar1, Al1, B1, Ar2, Al2, B2) is formed by at least three individual bearings. Device according to claim 3, characterized in that the individual bearings (Ar1, Al1, B1, Ar2, Al2, B2) symmetrical with respect to their bearing centers (L) to the plane of symmetry in the longitudinal direction of the Base element (8) of the boom system (6) arranged are. Device according to claim 4, characterized in that the individual bearings (Ar1, Al1, B1, Ar2, Al2, B2, Ar, Al, B, B *) when projected onto the carrier element (5) in the vertex of an isosceles triangle lie. Device according to one of claims 1 to 5, characterized characterized in that the individual bearings (Ar1, Al1, B1, Ar2, Al2, B1, Ar, Al, B) in one Level between the base element (8) of the boom system (6) and the carrier element (5) are arranged. Device according to one of claims 1 to 6, characterized characterized in that at least one single warehouse (B1) is provided with a spherical bearing (20). Device according to one of claims 1 to 7, characterized characterized in that in each individual warehouse (Ar1, Al1, B1, Ar2, Al2, B2) measuring elements (11Ar, 11Al, 11B, 22a, 22b) are provided. Device according to claim 8, characterized in that the measuring elements (11Ar, 11Al, 11B, 22a, 22b) one each with its ends (12a, 12b) in a bore (13a, 13b) in the support element (5) fixed support component (14) mounted load measuring bolt (11Ar, 11Al, 11B), the middle one Area over an eye support (17) with one on the base element (8) fixed component (18) for radial Power transmission is connected. Apparatus according to claim 9, characterized in that the load measuring pin (11Ar, 11Al, 11B) as a hollow cylinder is trained. Device according to one of claims 8 to 10, characterized by means of strain gauges (22a, 22b) the inside of the load measuring pin (11B). Device according to claim 11, characterized in that the strain gauges (22a, 22b) each in the area of the load center (L) of the load measuring pin (11B) are arranged. Device according to one of claims 1 to 12, characterized by a device for processing of the measured values. Device according to one of claims 1 to 13, characterized by a when a permissible measured value activated alarm unit. Device according to claim 14, characterized by an acoustic alarm unit. Device according to one of claims 8 to 15, characterized by a rotation lock (15) for the Load pin (11B). Device according to one of claims 8 to 16, characterized by distance elements (16) to the axial Adjustment. Device according to one of claims 1 to 17, characterized in that the individual warehouse each is provided with a spherical segment.

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