Abstract:
This disclosure relates to a truck-mounted concrete pump comprising a concrete-distributing boom which is constituted by a plurality of folding boom arms and rotationally mounted on a slewing gear on a chassis, and a tilt sensor for detecting a tilt of the truck-mounted concrete pump. According to this disclosure, the truck-mounted concrete pump is provided with a safety device which restricts the operating range of the concrete-distributing boom subject to a tilt of the pump, said safety device being coupled to the tilt sensor. The safety device is designed to limit the slewing motion on the slewing gear and/or the swiveling motion of at least one boom arm.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of PCT/EP2015/067383, filed Jul. 29, 2015, which claims priority to DE 10 2014 215 019.1, filed Jul. 30, 2014, both of which are hereby incorporated herein by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    The invention relates to a method for operating a truck-mounted concrete pump on the chassis of which a concrete-distributing boom, having a plurality of swivelable boom arms, is arranged rotatably on a slewing gear. The invention further relates to a truck-mounted concrete pump with a concrete-distributing boom having a plurality of swivelable boom arms and arranged rotatably on a slewing gear on a chassis, and with a tilt sensor for detecting an inclination of the truck-mounted concrete pump. 
         [0003]    Truck-mounted concrete pumps of this type are used on building sites in order to deliver concrete in a specified manner from the pump system via a concrete-distributing boom to variable work locations, the boom arms being moved, generally in a remote-controlled manner, by means of swivel drives. In order to ensure the required static stability, the machines must be supported during the working and pumping operation. In this regard it may happen that the environment at the building site has a slope of 3° and more. The machines are currently designed such that a maximum tilt thereof of 3° is permitted. Larger inclinations overload, inter alia, the slewing gear of the distributing boom and carry a risk of accident. In particular, there is a danger that stability and static safety limits may be exceeded. The inclination can be checked visually by the operator using a spirit level to measure tilt. In some cases additional measures must be taken. 
       SUMMARY 
       [0004]    Starting from the above considerations, it is desirable to improve the devices and methods known from the prior art and to provide an extended operating capability together with a reduced safety risk. 
         [0005]    This disclosure is based on the concept of detecting the inclination at the work location by means of sensors, and assisting the operator in operating the machine by program-controlled restriction of the operating range. Accordingly, with regard to the method, it is proposed that the inclination of the truck-mounted concrete pump is determined at the work location and that the operating range of the concrete-distributing boom is restricted by limiting the rotational movement at the slewing gear, and/or the swiveling movement of at least one boom arm, as a function of the inclination. Safe operation is thereby made possible even in the case of relatively large terrain slopes without the need for the operator to intervene independently in the system or to take account of complex operating conditions. 
         [0006]    Advantageously, the operating range is restricted as a function of the varying position of the center of gravity of the truck-mounted concrete pump resulting from the movement of the concrete-distributing boom, in such a way that the center of gravity remains within the tipping limits of the truck-mounted concrete pump. 
         [0007]    A further aspect provides that the operating range is restricted to avoid overstressing of components or overloading of structural members of the truck-mounted concrete pump. Here, in particular, the inclination of the slewing gear or the slant of support arms may be considered within defined limits. 
         [0008]    A further advantageous embodiment provides that the chassis is supported by means of at least three, preferably four extendable support arms and that the operating range is restricted according to the support configuration. The support configuration may be allowed for with reference to variable or fixed support arm positions (for example, full-width support or reduced-width support) while taking account of the degree of tilt, while a loading limit of the support arms may also be respected with regard, for example, to slope-induced downward forces. 
         [0009]    It is also advantageous if the detected inclination of the truck-mounted concrete pump is compared to a predetermined limit value, and if the operating range is restricted only if the limit value—set, for example, at 3°—is exceeded. 
         [0010]    To make possible automatic control it is advantageous if the inclination of the truck-mounted concrete pump is detected by means of a vehicle-mounted tilt sensor. In this case, the tilt of the vehicle vertical axis of the truck-mounted concrete pump may be detected by sensor means relative to the axis of gravity or to the horizon and/or to the terrain surface at the work location. 
         [0011]    In order to determine control parameters with an equipment cost as low as possible, it is advantageous if an angle of tilt of the truck-mounted concrete pump is detected both before and after the vehicle has been supported at the work location. In this way the terrain slope and the deviation therefrom of the three-dimensional inclination of the machine, depending on its supported position, can be incorporated in the calculation of the admissible operating range. 
         [0012]    As a general control principle, it is advantageous if the horizontal reach of the concrete-distributing boom is limited increasingly with increasing inclination of the truck-mounted concrete pump, so that the necessary static stability is always ensured and components are not overstressed. 
         [0013]    An especially simple variant, which is also uncomplicated for the operator, provides that the operating range of the concrete-distributing boom is restricted by setting the swiveled position of the first boom arm on the slewing gear at a predetermined angle. Alternatively, it is possible for the operating range of the concrete-distributing boom to be restricted by limiting the swiveling range of the first boom arm in relation to the horizontal. 
         [0014]    According to a further advantageous embodiment, the three-dimensional orientation of the truck-mounted concrete pump relative to the axis of gravity, or the three-dimensional inclination of the truck-mounted concrete pump, is detected, and the operating range of the concrete-distributing boom is restricted in dependence on said orientation or on said three-dimensional inclination, in particular by limiting the rotational range at the slewing gear. 
         [0015]    It is also advantageous for an improved human-machine interaction if the instantaneously possible reach of the concrete-distributing boom is displayed for an operator via a display device. 
         [0016]    As a further safety feature it is also advantageous if the movement of the concrete-distributing boom is stopped automatically upon reaching a limit of the operating range. 
         [0017]    It is also possible that the velocities and/or accelerations of the movement of the slewing gear or of the boom arms are limited as a function of the inclination, so that overstressing or additional tipping moments are avoided. 
         [0018]    The aforementioned advantages are also obtained for a truck-mounted concrete pump on which a concrete-distributing boom consisting of a plurality of swivelable boom arms and arranged rotatably on a slewing gear on a chassis, and a tilt sensor for detecting an inclination of the truck-mounted concrete pump, are provided, wherein a system coupled to the tilt sensor is configured, in particular, as a safety device for restricting the operating range of the concrete-distributing boom as a function of the inclination, and wherein the system or safety device is adapted to limit the rotational movement at the slewing gear and/or the swiveling movement of at least one boom arm. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The above-mentioned aspects of exemplary embodiments will become more apparent and will be better understood by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: 
           [0020]      FIG. 1  is a perspective view of a truck-mounted concrete pump in an inclined position with restricted operating range of the concrete-distributing boom; 
           [0021]      FIG. 2  shows a support configuration of a truck-mounted concrete pump in a schematic top view; and 
           [0022]      FIGS. 3 and 4  show side views of a truck-mounted concrete pump on inclined terrain in travelling and working positions. 
       
    
    
     DESCRIPTION 
       [0023]    The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of this disclosure. 
         [0024]    The truck-mounted concrete pump  10  shown in  FIG. 1  comprises a vehicle with a chassis  12 , a four-armed concrete-distributing boom  14  arranged thereon and serving as a carrier for a concrete delivery pipe, four laterally extendable support arms  16  for providing support in operation and a computer-aided safety device  20  coupled to at least one tilt sensor  18  for restricting the operating range of the concrete-distributing boom  14  as a function of an inclination of the vehicle. 
         [0025]    In the exemplary embodiment shown, the concrete-distributing boom  14  comprises four boom arms  22 ,  24 ,  26 ,  28  in the form of pivot-jointed extendable arms. The first boom arm  22  is articulated at one end to a boom bearer or slewing gear  32  which is rotatable about a vertical axis  30  of the chassis  12  by activation of a rotary drive. Furthermore, the boom arms  22 ,  24 ,  26 ,  28  are swivelable, by associated swivel drives, about horizontal axes with respect to the slewing gear  32  and to each adjacent boom arm. The final boom arm  28  carries at its free end an end hose of the concrete delivery pipe (not shown separately). 
         [0026]    The front extendable support arms  16  can be deployed telescopically from a retracted travelling position to an extended, obliquely forward-oriented support position. The two rear extendable support arms can be swiveled from a travelling position aligned parallel to the chassis to an obliquely rearward-oriented support position. All the extendable support arms  16  have a telescopic support leg  34  with which they can be supported on a substrate while raising the chassis  12 . Depending on the space requirement at the work location or building site, the extendable support arms  16  can be supported selectively on the substrate so as to form different deployment configurations: with their support legs  34  in an inner support position close to the chassis or in an outer support position at a distance from the chassis. 
         [0027]    As represented in  FIG. 2 , the tipping limits  36  of the truck-mounted concrete pump  10  are defined by the position of the support legs  34 . In order for the machine to stand securely, the center of gravity must always be located within the tipping limits  36 , as is shown for a possible center of gravity line  38  during a 360° rotation of the concrete-distributing boom  14 . 
         [0028]    Accordingly, static stability is put at risk when vehicle inclination is outside an inclination range of, for example, not more than 3°. In addition, the support legs  34  and the slewing gear  32  can be overstressed by the direction-dependent loadings which occur with an inclined position of the vehicle. 
         [0029]      FIG. 1  shows the case in which the terrain  40  at the work location has a terrain inclination  42  with respect to the horizontal  44 , such that the vertical axis  30  deviates in operation from the axis of gravity  46  (normal to the horizontal) by an angle β of, for example, 5°. In this case the operating range  48  of the concrete-distributing boom  14  is restricted appropriately by the electronic safety device  20  in order to ensure the required static stability and to avoid overloadings. This is achieved by limiting the rotary motion at the slewing gear  32  and/or the swiveling movement of at least one boom arm as a function of the inclination of the truck-mounted concrete pump  10 . 
         [0030]    This inclination is suitably detected three-dimensionally and in a direction-dependent manner by means of the tilt sensor  18  mounted on the vehicle, so that not only the absolute inclination angle β, but also the horizontal angle of the largest inclination of the vehicle with respect to a zero position of the slewing gear  32 , for example in the longitudinal direction of the vehicle, is also known. 
         [0031]    In order to ensure the necessary static stability, different strategies for moving the boom can be determined by means of a software of the safety device  20 . The horizontal reach of the concrete-distributing boom  14  should advantageously be limited increasingly with increasing inclination of the truck-mounted concrete pump  10 . In principle, it might also be sufficient to limit the accelerations or jolting (time derivative of the acceleration). 
         [0032]    An especially simple control routine provides that the operating range  48  is restricted by setting the swiveled position of the first boom arm  22  on the slewing gear  32  at a predetermined angle—for example 90°, as shown in  FIG. 1 , while the other boom arms  24 ,  26 ,  28  remain freely movable. This has the advantage that the operator can still ascertain visually the reach of the arms package in a simple manner. 
         [0033]    Alternatively, it is possible for the swiveling range of the first boom arm  22  with respect to the horizontal to be limited (for example, between 90° and 45°), so that the swiveling range does not fall below a limit angle set as a function of the inclination and the support configuration. 
         [0034]    A further configuration of the safety device  20  provides for a restriction of the range of rotation of the concrete-distributing boom  14  on the slewing gear  32 . As already mentioned, a multi-axis tilt sensor  18  can determine three-dimensionally the inclination of the machine with respect to the axis of gravity. Accordingly, the range of rotation of the boom  14  can be restricted; for example, when the machine is located on a slope, a downhill segment of the angular range may be excluded (limiting the maximum angle with respect to the oblique plane or to the axis of the slope-induced downward force). This configuration may also be used in combination with the other possibilities. 
         [0035]    A possible process sequence is explained below with reference to  FIGS. 3 and 4 . The operator parks the truck-mounted concrete pump  10  at a work location where the terrain has a slope of more than 3°. The terrain slope a is detected by means of the vehicle-mounted tilt sensor  18  while the extendable support arms  16  are still retracted ( FIG. 3 ). The support configuration in which the support legs  34  are extended by different amounts in order to reduce the inclination is then adopted ( FIG. 4 ). In certain cases it is still not possible by this means to support the machine within a 3°-inclination range, although the inclination angle β is still smaller than the terrain slope angle α. 
         [0036]    The elevated inclination can be displayed to the operator via a display system, for example, on a radio control system for the distributing boom  14 . According to the inclination, the safety device  20  determines which possibilities the operator has for operating the distributing boom  14 . For example, the operating range  48  may be adapted on the basis of the support configuration. In the case of full-width support, the complete rotational range of the slewing gear may be permitted, whereas with reduced-width support a restricted swivel range is allowed. The horizontal reach of the boom arm package is restricted, for example, in dependence on the inclination (reduction of the tipping moment of the machine/truck-mounted concrete pump  10  and reduction of loading on components). The greater the inclination, the more the horizontal reach is restricted. 
         [0037]    The horizontal position of the end hose can be ascertained by the safety device  20  by means of, for example, tilt or angle sensors on the individual boom arms. The possible radii of action may be displayed to the operator by means of a display device. If the operator moves the distributing boom  14  into a limit range determined by the safety device  20 , movement of the boom is stopped automatically. Notification to the operator may be given on the display device. The operator may move the boom arm package back out of the limit range. Optionally, the operator may already be informed by a notification before the limit range has been reached. The notification may be effected visually, haptically or acoustically. 
         [0038]    While exemplary embodiments have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.