EP2342400B1 - Mobile work machine having support brackets - Google Patents

Abstract

The invention relates to a mobile work machine having a chassis (10) and with two front and two rear support brackets (20, 22). The support brackets can be displaced from a driving position close to the chassis into a support position by changing the base angles (α) thereof and/or can be telescoped by changing the lengths thereof between the end on the mounting side and that on the free end. In order to be able to automatically determine the support leg positions (Xc/Yc) in relation to the chassis (10), three transceiver units (S1/E1, S2/E2, S3/E3) related to the support legs are provided for transmitting and receiving run time or distance signals. Furthermore, a microprocessor-supported evaluation unit responding to the transmitted and received signals of the transceiver units arranged in pairs is provided, comprising a software routine for determining the support leg positions in a coordinate system (x/y) fixed to the chassis.

Description

The invention relates to a mobile work machine with a chassis and two front and two rear support arms, the support arms are mounted with a bearing-side end to a chassis-fixed rotary or sliding joint, wear at its free end a telescopic and supportable on the ground support leg and from a driving position close to the chassis in a support position while changing a base angle between the support arm and chassis are pivotable and / or telescopically changing the length of its support arm between the bearing side and free end, and wherein the transmitting and receiving units are arranged on the support arms.

Mobile working machines of this type are, for example, truck-mounted concrete pumps, which serve as a support for a conveyor concrete distributor, which is articulated with its first mast arm on a rotatable about a vertical axis of the chassis rotating a rotary drive and driving the mast arms by driving associated buckling with respect to the turret and opposite each adjacent mast arm are pivotable about horizontal buckling axes. Other applications include mobile cranes or mobile extension ladders.

It is in a truck crane of the type indicated above known ( EP 1 772 415 A2 ) to provide at the support arms transmitting and receiving units with which the position of the support arm is determined to monitor the stability of the working machine.

Supported with their support legs on the ground support boom limit with lifted chassis a support quadrilateral with four between the adjacent corners extending tilting edges, the center of gravity of the system should not be exceeded to the outside. In the case of a truck-mounted concrete pump with fully extended and supported support arms usually a rotation of the fully unfolded and horizontally oriented Betonverteilermasts 360 ° of its rotary head possible without a risk of tipping exists. Furthermore, it is known, especially in narrow construction sites, that the support arms only on one side be extended and supported on the chassis, while they are supported on the other side in its pivoted position on the ground. In this case, there is a limited work area of the concrete boom after the supported by the extended support arm side.

Next it is from the DE-10 2006 031 257 A1 in a truck-mounted concrete pump, that each support boom has a chassis-near and at least one chassis-distant support position, which are freely selectable to form defined support configurations for the four support arms. In each Abstützkonfiguration only such mast movements are allowed in which the center of gravity of the machine moves without the risk of incorrect operation within the support quadrilateral, ie within the tilting edges. For variable support leg displays, it is important to know the support leg positions. This is the only way to make a prediction about the stability of the support. For safety reasons, the support legs could only be positioned in certain discrete positions in the known support devices. These positions are selected by the concrete pump driver depending on the space available at the workplace. A disadvantage is felt here that intermediate positions of the supporting device, which would be possible in place at the workplace, are not allowed.

Proceeding from this, the present invention seeks to improve the known work machine of the type specified in that automatic detection of the support leg positions and thus the allowable load moments is possible, so that in their installation without loss of stability, a higher variability in the positioning of the Support legs consists.

To solve this problem the features specified in claim 1 are proposed. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The inventive solution is based primarily on the idea that an automatic determination of the support leg positions is metrologically possible, so that can be determined for each Abstützkonfiguration the support quadrilateral whose side edges of the center of gravity of the system in the movement of a work jib must not be exceeded. To achieve this, it is proposed according to the invention that in each case three support arm-related transmitting and receiving units are provided for the transmission and reception of transit time or distance signals, of which a first transmitting and receiving unit at a chassis-fixed bearing-side reference point in the immediate vicinity of the fixed chassis Rotary or sliding joint, a second transmitting and receiving unit are arranged at a defined distance from the bearing-side reference point fixed chassis reference point and a third transmitting and receiving unit at a boom-fixed reference point in the vicinity of the free support arm end respectively so that their transmission signals alternately to straighter Route to the adjacent receivers are transferable and wherein on the mutually paired transmit and receive signals of the transmitting and receiving units responsive microprocessor-based evaluation is provided, which is a Softwarerouti ne for determining the cantilever fixed reference point or the support leg position in a chassis fixed coordinate system. The three reference points according to the invention span a triangle, which can be measured via the transmitting and receiving units arranged there in the manner of a triangulation method, by determining the support leg positions selected in a specific setting. The triangular corners defined by the reference points must face each other freely, so that a trouble-free measurement is possible.

A preferred embodiment of the invention provides that the transmitting and receiving units each have an ultrasonic transmitter and an ultrasonic receiver, which in pairs between the reference points in can be used in both directions and thus redundant distance measuring system. The distance is determined in each case by a transit time measurement. The known distance between the first and the second fixed chassis reference point can be used as a reference for determining the two variable distances to the boom-fixed reference point. At the same time a temperature compensation is possible, which takes into account the temperature dependence of the speed of sound. A trouble-free measurement is made possible by the fact that the transmitting and receiving units overlap in their effective range. In order to assign the transmit and receive signals of the three different transmitting and receiving units of each support arm each other correctly, it is advantageous if the transmission signals each have an identifiable at the receivers coding.

In principle, it is possible to equip the transmitting and receiving units with light transmitters or light receivers, wherein the light emitter can be designed as a laser. The use of radio transmitters and radio receivers in the transmitting and receiving units is also possible.

A particularly advantageous application of the invention is possible in truck-mounted concrete pumps. For this purpose, the mobile work machine advantageously arranged on a chassis-fixed base, serving as a support for a conveyor line and having at least three mast arms articulated mast, the first mast arm hinged with a free end to a rotatable about a vertical axis of the chassis by driving a rotary drive rotary head is and wherein the mast arms by controlling associated buckling with respect to the turret and / or each adjacent mast arm are pivotable about horizontal buckling axes.

Fig. 1a

eine Seitenansicht einer Autobetonpumpe mit Stützauslegern in Fahrstellung;

Fig. 1b

eine Draufsicht auf die Autobetonpumpe nach Fig. 1a mit Stützauslegern in verschiedenen Abstützstellungen;

Fig. 2

ein Schema eines vorderen Stützauslegers mit Positionsmesssystem;

Fig. 3

Schema des Wirkbereichs der Sende-/Empfangseinheiten;

Fig. 4

eine geometrische Darstellung des Ausführungsbeispiels nach Fig. 2 zur Ermittlung der Stützbeinposition (Objekt) durch Triangulation;

In the following the invention will be explained in more detail with reference to an embodiment shown schematically in the drawing. Show it

Fig. 1a

a side view of a truck-mounted concrete pump with support arms in driving position;

Fig. 1b

a plan view of the truck-mounted concrete pump Fig. 1a with support arms in different support positions;

Fig. 2

a diagram of a front support arm with position measuring system;

Fig. 3

Scheme of the effective range of the transmitting / receiving units;

Fig. 4

a geometric representation of the embodiment according to Fig. 2 for determining the support leg position (object) by triangulation;

In the Fig. 1a and b shown truck concrete pump consists essentially of a multi-axle chassis 10 with two front axles 11 and three rear axles 12, with a cab 13, a rotatably mounted on a near-axis turntable 14 about a vertical axis concrete boom 15, with a distance from the slewing gear 14 on the chassis 10th The support structure 18 has a chassis-fixed support frame 19 and comprises two front support boom 20 and two rear support boom 22, which are retracted in the transport position and aligned parallel to the vehicle longitudinal axis 24 and inclined in the support position protrude forward or back over the chassis 10.

The front support arms 20 are pivotable about their vertical pivot axes 32 and the rear support arms 22 about their vertical pivot axes 34 between the driving position and a support position under the action of a respective Ausstellzylinders 36. Next point all support arms 20, 22 at its free end a telescoping support leg 26,28, with which they can be supported on a substrate 30 by lifting the chassis 10.

The front support arms 20 are designed as a telescopic boom. They each include a pivotable about the vertical pivot axis 32 relative to the chassis Ausschubkasten 38 and one of three telescopic segments 40 ', 40 ", 40"' existing telescope part 40. Through the Ausschubkasten 38 and the telescopic part 40 extends through a multiple telescoping, in the Drawing of unillustrated hydraulic cylinders. How out Fig. 1 b can be seen, the support arms can be supported depending on the space required at the construction site either to form various Ausstellkonfigurationen in an inner, chassis-mounted or an outer chassis distant support with their support legs on the ground. A special feature of the present invention is that all intermediate positions between the inner and the outer support position are possible. The latter is made possible by the fact that a measuring arrangement is provided with which the position of the support leg 26 can be automatically determined in a frame-fixed coordinate system.

• Bekannt sind die Längen der Dreieckseiten a, b und c aus den Wegmessungen gemäß Fig. 2. Gesucht sind die Koordinaten X_C/Y_C im x/y-Koordinatensystem.

The measuring system has on each support arm each three transmitting and receiving units S ₁ / E ₁ , S ₂ / E ₂ and S ₃ / E ₃ , which are designed for the transmission and reception of runtime or distance signals. Preferably, ultrasound transmitters and receivers are used for this purpose. In principle, however, it is also possible to use light or radio transmitters and receivers. A first transmitting and receiving unit S ₁ / E ₁ is fixed to the chassis in a bearing-side reference point A in the immediate vicinity of the chassis-fixed pivot joint 32. A second transmitting and receiving unit S ₂ / E ₂ is located at a defined distance L _12/21 from the bearing-side reference point A fixed chassis reference point B, while a third transmitting and receiving unit S ₃ / E ₃ at a boom-fixed reference point C in the Near the free end of the support arm 40 is arranged. The reference points A, B and C, at which the transmitting and receiving units are located, are according to Fig. 3 arranged so that overlap their effective ranges W ₁ , W ₂ , W ₃ , so that their transmission signals are mutually echo-free on a straight line to the receivers of the other reference points transferable. The reference points A, B, C clamp according to Fig. 2, 3 and 4 a triangle whose side lengths can be measured by means of the transmitting and receiving units by transmitting and receiving ultrasonic signals in both directions. The length values are labeled L ₁₂ and L ₂₁ , L ₂₃ and L ₃₂ and L ₁₃ and L ₃₁ , depending on the direction of their measurement. The measurement is carried out in the two directions in order to obtain a redundancy and thus a higher reliability in the measurement results. The aim of the measuring arrangements in different support legs is to determine the support leg position and thus the object point X _C / Y _C in the frame-fixed coordinate system x / y. Taking into account the geometric arrangement in Fig. 4 the coordinates X _C and Y _C in the object point C are calculated as follows:

• The lengths of the triangle sides a, b and c are known from the distance measurements according to FIG Fig. 2 , We are looking for the coordinates X _C / Y _C in the x / y coordinate system.

$$\alpha =\arccos \frac{\left(b^2+c^2-a^2\right)}{2\cdot b\cdot c}$$

After the cosine rate applies $$\cos \alpha =\frac{\left(b^2+c^2-a^2\right)}{2\cdot b\cdot c}$$

$$\alpha =\arccos \frac{\left(b^2+c^2-a^2\right)}{2\cdot b\cdot c}$$

$$y_C=\sin \left(90°-a\right)\cdot b$$

From this, the coordinates of the object point are calculated as follows $$x_C=\mathrm{<figure-callout\; id="90"\; label="cos"\; filenames="imgf0002.png"\; state="\{\{state\}\}">cos</figure-callout>}\left(90°-\alpha \right)\cdot b$$

$$y_C=\mathrm{<figure-callout\; id="90"\; label="sin"\; filenames="imgf0002.png"\; state="\{\{state\}\}">sin</figure-callout>}\left(90°-a\right)\cdot b$$

The length measurements of the triangle sides are scaled for further calculation. In the case of signal scaling, the redundancy in the length measurement in the two directions is taken into account and evaluated. In this case, the vehicle-fixed distance L ₁₂ / L _{21 is used} as a reference path for a temperature compensation and for determining correction factors for the other two length measurements. The calculation of the support leg position is then based on the above equations.

In summary, the following should be noted: The invention relates to a mobile work machine with a chassis 10 and with two front and two rear support arms 20,22. The support arms are pivotable from a driving position close to the chassis into a support position with a change in their base angle α between the support arm and the chassis and / or telescopically changing their length between the bearing side and the free end. In order to enable an automatic determination of the support leg position X _c / Y _c with respect to the chassis 10, each three support arm-related transmitting and receiving units S ₁ / E ₁ to S ₃ / E _{3 are provided} for transmitting and receiving runtime or distance signals , Furthermore, a microprocessor-based evaluation unit which responds to the mutually paired transmit and receive signals of the transmitting and receiving units is provided which has a software routine for determining the support leg position in a chassis-fixed coordinate system x / y.

Claims (8)

1. Mobile work machine having a chassis (10) and having support booms (20, 22), whereby the support booms (20, 22) are mounted, with a bearing-side end, on a swivel joint or slider joint (32, 34) fixed in place on the chassis, carry a telescoping support leg (26, 28) that can be supported on the subsurface at their free end, and can be moved out from a travel position, close to the chassis, into a support position, away from the chassis, by being pivoted, changing the basic angle (α) between support boom (20, 22) and chassis (10), and/or by being telescoped, changing the length between their bearing-side end and their free end and wherein transmission and reception units are arranged at the support booms, characterized by three support-boom-related transmission and reception units, in each instance, for transmission and reception of running time signals or distance signals, with a first transmission and reception unit (S₁/E₁) being disposed at a reference point (A) on the bearing side, fixed in place on the chassis, in the immediate vicinity of the swivel joint or slider joint (32) fixed in place on the chassis, a second transmission and reception unit (S₂/E₂) being disposed at a reference point (B) fixed in place on the chassis, disposed at a defined distance (L₁₂, L₂₁) from the bearing-side reference point (A), and a third transmission and reception unit (S₃/E₃) being disposed at a reference point (C) in the vicinity of the free support boom end, fixed in place on the boom, in such a manner, in each instance, that their transmission signals can be alternately transmitted to the receiver of an adjacent transmission and reception unit, and whereby a microprocessor-supported evaluation unit that responds to the transmission and reception signals of the transmission and reception units, which are assigned to one another in pairs, is provided, which unit has a software routine for determining the coordinates (X_c/Y_c) of the boom-fixed reference point (C) or the position of the support leg (26, 28) in a chassis-fixed coordinate system (x/y).
2. Mobile work machine according to claim 1, characterized in that the transmission and reception units have an ultrasound transmitter and an ultrasound receiver.
3. Mobile work machine according to claim 1, characterized in that the transmission and reception units have a light transmitter and a light receiver.
4. Mobile work machine according to claim 3, characterized in that the light transmitter has a laser.
5. Mobile work machine according to one of claims 1 to 4, characterized in that the transmission and reception units that are adjacent to one another have overlapping ranges of effect.
6. Mobile work machine according to one of claims 1 to 5, characterized in that the transmission signals of the transmission and reception units have a coding that can be identified by the receivers of the transmission and reception units.
7. Mobile work machine according to one of claims 1 to 6, characterized in that the defined distance (L₁₂/L₂₁) between the first bearing-side, chassis-fixed reference point (A) and the second chassis-fixed reference point (B) forms a reference distance for the other reception measurements.
8. Mobile work machine according to one of claims 1 to 7, characterized by a bending mast that serves as a carrier for a feed line, disposed on a substructure fixed in place on the chassis, and has at least three mast arms, which is articulated, with its one end, onto a rotating head (14) that can be rotated about a vertical axis of the chassis (10).

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