Abstract:
A device for controlling trimming flaps ( 12, 13 ) of a watercraft ( 10 ), preferably having two trimming flaps ( 12, 13 ) and in each case at least one hydraulically operated for adjustment of the inclination angle ( 15 ) of the associated trimming flap ( 12, 13 ). The invention provides that the or each hydraulic system ( 18 ) has an associated flowmeter ( 21 ) which detects the flow of hydraulic fluid in the hydraulic system ( 18 ) in order to determine the inclination angle ( 15 ) of the associated trimming flap ( 12, 13 ). This makes it possible to dispense with external measurement devices for detection of the position of the trimming flaps, for example appropriate position sensors. The invention also relates to a corresponding method, and to watercraft having a corresponding device.

Description:
BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The invention relates to a device for controlling trimming flaps on a watercraft, having preferably two trimming flaps and in each case at least one hydraulically operated system for adjustment of the inclination angle of the associated trimming flap. The invention also relates to a watercraft preferably two trimming flaps for alignment of the watercraft at different speeds. The invention also relates to a method for controlling trimming flaps on a watercraft with the inclination angle of the trimming flaps being varied by means of a hydraulically operated system. 
   2. Prior Art 
   The trimming flaps under discussion here are generally arranged in the stern area of watercraft and are used to influence the attitude of the watercraft in the water at different speeds. The trimming flaps are preferably mounted on an approximately horizontally aligned pivoting shaft and can be pivoted with respect to the shaft, that is to say for example they can be raised or lowered via a hydraulically operated means, for example a hydraulic cylinder. The corresponding inclination angle of the trimming flap in this case governs the attitude of the watercraft in the water. The watercraft can be kept at an essentially flat attitude in the water by controlling the inclination angle of the trimming flaps. 
   The trimming flaps are generally controlled manually by the user, for example from the bridge of the watercraft. The inclination angle of the trimming flaps can be controlled by operation of appropriate switches, levers or the like. One problem relating to the control of the inclination angles of the trimming flaps is, in particular, that the optimum inclination angle is dependent on the speed of the watercraft and must therefore be adapted by the user in order that the watercraft is as far as possible always aligned at an optimum attitude (preferably essentially flat) in the water. 
   In general, the inclination angles of the trimming flaps are varied via hydraulically operated means, for example with the aid of hydraulic cylinders. In order to make it easier for the user to adjust the trimming flaps and their inclination angles, it is normal to indicate the position of the trimming flaps to the user. It is thus necessary to detect the current inclination angle of the trimming flaps in order, for example, to display this on the bridge by means of a suitable instrument, so that the user can make appropriate corrections, for example when the speed of the watercraft changes. 
   It is known in practice for the position of the trimming flaps to be detected by means of mechanical position sensors on the hydraulic cylinders. However, this requires wiring to the hydraulic cylinders in order to make it possible to detect, pass on and indicate the appropriate data. It has been found that this procedure has certain disadvantages because appropriate position sensors or signal lines may be damaged during operation, which damage must be repaired, and this is costly. 
   BRIEF SUMMARY OF THE INVENTION 
   Against this background, the invention is based on the object of further developing devices and methods of the type mentioned initially, in particular with respect to determination of the inclination angles of the trimming flaps in a manner which is as insensitive as possible to defects and with respect to automatically controlling the inclination angles in as simple a manner as possible. 
   A device for controlling trimming flaps of a watercraft, preferably having two trimming flaps and in each case at least one hydraulically operated system for adjustment of the inclination angle of the associated trimming flap, characterized in that the or each hydraulic system has an associated flowmeter which detects the flow of hydraulic fluid in the hydraulic system in order to determine the inclination angle of the associated trimming flap, proposed in order to achieve this object. The invention accordingly provides that the or each hydraulic system has an associated flowmeter which detects the flow of hydraulic fluid in the hydraulic system in order to determine the inclination angle of the associated trimming flap or flaps. A change to the inclination angle of the trimming flap or flaps can be determined by detection of the flow of the hydraulic fluid. For example, integration of the flowmeter in the hydraulic cylinder or in hydraulic lines which lead to the cylinder or in a comparable manner means that there is no need for wiring outside the hydraulic drive for the trimming flap or flaps in order to detect the position of the trimming flap or flaps. The damage which is known from the prior art can therefore not occur with the device according to the invention. 
   One preferred refinement of the invention provides that the hydraulic system has at least one hydraulic cylinder for adjustment of the inclination angle of the trimming flap or flaps, as well as a hydraulic unit for operation of the hydraulic cylinder, with the hydraulic cylinder and the hydraulic unit being connected by hydraulic lines. The flowmeter can preferably be associated with each of the hydraulic lines which lead from a hydraulic unit to the or each hydraulic cylinder. Furthermore, provision is preferably made that the hydraulic unit and the flowmeter are arranged inboard, and are thus protected against damage. 
   One preferred development of the invention provides that the or each hydraulic unit and/or the or each flowmeter is connected via lines to a control unit in order to control and/or indicate the inclination angle of the trimming flap or flaps. The control unit can thus be used to evaluate and/or to influence the position of the trimming flap or flaps. It is feasible on the one hand for the inclination angles of the trimming flap or flaps to be controlled automatically by the control unit. However, it is also feasible for the control unit to detect appropriate user commands and to implement them by operation of the hydraulic unit. 
   One particularly preferred development, which may also be used as an autonomous solution to achieve the initially mentioned object, provides that the inclination angles of the trimming flap or flaps can be controlled by the control unit automatically and as a function of the speed of the watercraft and/or of the rotation speed of a or each motor of the watercraft. This means that the control unit avoids the user having to carry out the task of matching the inclination angle of the trimming flap or flaps to the respective vehicle speed. 
   One preferred development of the invention provides that a trimming curve is stored in the control unit, from which a preferred inclination of the trimming flap or flaps as a function of the speed of the watercraft and/or of the motor rotation speed is obtained for automatic control of the inclination angle of the trimming flap or flaps. The trimming curve can preferably be varied by the user. 
   By way of example, the speed of the watercraft can be determined in a simple manner by means of a GPS receiver, which passes the corresponding data to the control unit in order in this way to allow the inclination angles of the trimming flap or flaps to be controlled. 
   A corresponding method in order to carry out the object mentioned in the introduction is a method for controlling trimming flaps of a watercraft, with the inclination angle of the trimming flaps being varied by means of a hydraulically operating system, characterized in that the hydraulic system has an associated flowmeter by means of which the flow of the hydraulic fluid is measured in order to determine the inclination angle of the trimming flap. This provides that the hydraulic system has an associated flowmeter by means of which the flow of the hydraulic fluid is measured in order to determine the inclination angle of the trimming flap or flaps. In this case as well, a change in the inclination angle can be detected in principle by monitoring the flow of the hydraulic fluid. Starting from a known actual inclination angle, for example the maximum or minimum inclination angle, the current inclination angle can thus be determined by observation of the change in the inclination angle. 
   Preferred developments of the invention are specified in the dependent claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One preferred exemplary embodiment of the invention will be explained in more detail in the following text with reference to the drawings, in which: 
       FIG. 1  shows a schematic illustration of a system for controlling the inclination angle of trimming flaps on a watercraft, 
       FIG. 2  shows a side view of a watercraft with trimming flaps, 
       FIG. 3  and  FIG. 4  show various positions of the trimming flap, 
       FIG. 5  shows a schematic illustration of the hydraulic operation of the trimming flaps, and 
       FIG. 6  shows a trimming curve for automatic control of the inclination angle of the trimming flaps as a function of the speed of the watercraft. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 to 6  show one preferred embodiment of a system for controlling the inclination angle of trimming flaps on a watercraft. It is self-evident that the following description of the exemplary embodiment indicates only one of many options for implementation of the invention. In principle, departures may be made at individual points from the described solution without departing from the fundamental idea of the invention. The following description should in no way be regarded as any restriction to the scope of protection of the patent claims to the described exemplary embodiment. 
     FIG. 2  shows a side view of a watercraft  10 . Two trimming flaps  12 ,  13  are arranged in the area of the stern  11  of the watercraft, to be precise a starboard trimming flap  12  and a port trimming flap  13 . 
   In a plan view, the two trimming flaps  12 ,  13  are preferably arranged at the same distance laterally from the longitudinal center axis of the watercraft  10 , which is not shown. The two trimming flaps  12 ,  13  are each mounted on the watercraft  10  such that they can pivot. The bearing is in the form of a hinge-like joint  14  in the area of the stern  11 . The hinge-like joint  14  is aligned approximately horizontally and is preferably arranged underneath the water level. 
   The trimming flaps  12 ,  13  can be pivoted in the vertical direction about the joints  14 , specifically between an upper limit position ( FIG. 4 ) and a lower limit position ( FIG. 3 ). The capability of the trimming flaps  12 ,  13  to pivot changes their inclination angles  15  with respect to an imaginary horizontal plane  16  which runs through the axis of the joint  14 . In the illustrated exemplary embodiment, the trimming flaps  12 ,  13  point 2° upwards in the upper limit position shown in  FIG. 4 . The inclination angle  15  in the lower limit position as shown in  FIG. 3  is approximately 10°. The inclination angles  15  in the upper and lower limit positions are freely configurable and can be matched to the respective requirements and circumstances. 
   In principle the trimming flaps  12 ,  13  are used to influence the attitude of the watercraft  10  in the water. For this purpose, the trimming flaps  12 ,  13  are adjusted as a function of the speed of the watercraft  10  such that the watercraft  10  remains essentially flat in the water. In principle, the trimming flaps  12 ,  13  can be pivoted both synchronously and individually. 
   The trimming flaps  12 ,  13  are pivoted via hydraulic cylinders  17 . The hydraulic cylinders  17  are arranged above the trimming flaps  12 ,  13  at the stern  11  of the watercraft  10 , and are connected to the upper face of the trimming flaps  12 ,  13 . The inclination angle  15  of the trimming flaps  12 ,  13  can be adjusted in this way, by extension and retraction of the hydraulic cylinder  17 . 
   Each trimming flap  12 ,  13  may use one or more hydraulic cylinders  17 . The hydraulic cylinders  17  may be single-acting or double-acting hydraulic cylinders  17 . In the present exemplary embodiment each trimming flap  12 ,  13  in each case has two associated hydraulic cylinders  17 , which are in the form of double-acting cylinders (see  FIG. 5 ). 
   The hydraulic cylinders  17  are part of hydraulically operated systems for adjustment of a trimming flap  12 ,  13 , referred to for short in the following text as a hydraulic system  18 . In the present exemplary embodiment, as described above, a hydraulic system  18  has a hydraulic cylinder  17 , a hydraulic unit  19  and the hydraulic lines  20  which run between the hydraulic unit  19  and the hydraulic cylinders  17 . Each trimming flap  12 ,  13  and the hydraulic cylinders  17  arranged on it are in this case associated with one and only one hydraulic system  18  with a separate hydraulic unit  19 , so that the trimming flaps can be operated independently of one another. 
   One special feature is that one flowmeter  21  is in each case integrated in each circuit in the hydraulic system  18 . The flow of the hydraulic fluid within the respective hydraulic system  18  can be determined with the aid of the flowmeters  21 . The change in the inclination angles  15  of the trimming flaps  12 ,  13  can then be deduced from the change in the flow of the hydraulic fluid. The flowmeters  21  are preferably integrated in the hydraulic lines  20 . This allows the flowmeters  21  to be positioned inboard, so that they are protected against external influences and damage. The appropriate position of the transom  30  is evident, for example, from the schematic illustration shown in  FIG. 5 . Alternatively, it is also feasible to associate the flowmeters  21  with the hydraulic cylinders  17  or the hydraulic units  19 . 
   The flowmeters  21  are used to determine the flow of hydraulic fluid in the hydraulic system  18 . For this purpose, the system must first of all be calibrated. For this purpose, the trimming flaps  12 ,  13  are first of all moved to one limit position, and then to the other limit position. During this process, the flow of hydraulic fluid is recorded, and a measure is obtained for the maximum movement. The flowmeters  21  in this case produce a number of pulses, as data, proportional to the amount of flow. In this case, one pulse in each case corresponds to a specific amount or a specific flow volume. 
   The system is controlled by a central control unit  22 . The control unit is connected by means of electronic lines  23  to the hydraulic units  19  and the flowmeters  21 . Furthermore, a voltage supply  24  is provided in order to supply at least the control unit  22 . The central control unit  22  can calculate the variation in the inclination angle of the trimming flaps  12 ,  13  on the basis of the pulses which are transmitted from the flowmeters  21  during the calibration and during operation. The position of the trimming flaps  12 ,  13  can then be indicated on the bridge of the watercraft  10  by means of the display  25  which is connected to the control unit  22 . 
   Furthermore, a control panel  26  is provided, and can likewise be connected to the central control unit  22 . The control panel  26  allows the inclination angle  15  of the trimming flaps  12 , 13  to be varied manually. A separate button for pivoting the respective trimming flap  12  or  13  up or down is provided for this purpose for each respective trimming flap  12  or  13 . 
   As a further special feature, the inclination angles  15  of the trimming flaps  12 , 13  can also be controlled automatically. In this case, the inclination angles  15  can be controlled as a function of the speed of the watercraft  10  and/or of the rotation speed of the or each motor. 
   In the illustrated exemplary embodiment, a GPS receiver  27  is connected to the display  25 . The GPS receiver  27  provides information about the speed of the watercraft  10 , in the normal manner. The speed can on the one hand be indicated on the display  25  and is on the other hand transmitted to the control unit  22 . 
   A trimming curve  28  is stored in the control unit  22 , indicating the preferred inclination angles  15  as a function of the speed of the watercraft and the motor rotation speed. The following Table 1 contains examples of data for a trimming curve  28  such as this, for illustrative purposes: 
   
     
       
             
             
             
           
             
             
             
           
         
             
               TABLE 1 
             
             
                 
             
             
                 
               Max. GPS speed 
               Trim angle 
             
             
               RPM 
               (kn) 
               (°) 
             
             
                 
             
           
           
             
                 
             
           
        
         
             
               700 
               7.6 
               −4.0 
             
             
               800 
               8.3 
               −4.0 
             
             
               900 
               9.1 
               −4.0 
             
             
               1000 
               10.0 
               −4.0 
             
             
               1100 
               10.7 
               −4.0 
             
             
               1200 
               11.4 
               −4.0 
             
             
               1300 
               12.0 
               −4.0 
             
             
               1400 
               12.6 
               −4.0 
             
             
               1500 
               13.3 
               −4.0 
             
             
               1600 
               15.8 
               5.0 
             
             
               1700 
               17.4 
               5.0 
             
             
               1800 
               19.0 
               5.5 
             
             
               1900 
               20.9 
               5.5 
             
             
               2000 
               23.0 
               3.0 
             
             
               2100 
               25.1 
               3.0 
             
             
               2200 
               26.9 
               3.5 
             
             
               2300 
               28.6 
               4.0 
             
             
               2348 
               29.5 
               5.5 
             
             
                 
             
           
        
       
     
   
     FIG. 6  also illustrates a corresponding trimming curve  28 . The trimming curve  28  can also be varied by the user. For example, it is feasible to indicate the data or the trimming curve  28  on the display  25 . The data can also be varied as required by means of the control panel  26  or by some other input means. 
   If no display  25  is provided, the GPS receiver  27  can also alternatively be connected directly to the central control unit  22 . This solution is illustrated by dashed lines in  FIG. 1 . The figure does not show the transmission of the motor rotation speeds to the central control unit  22 . 
   Dashed lines are likewise used to illustrate further indication instruments which may be provided as an alternative to and/or in addition in the display  25 . This or these is or are in the form of one or more instruments  29  on which, for example, it is possible to display the best position of the trimming flaps  12 ,  13  and the existing positions of the trimming flaps  12 ,  13 . 
   In order to allow switching between automatic control of the trimming flaps  12 ,  13  and manual control, provision is made for an appropriate switch which, in the illustrated exemplary embodiment, is associated with the control panel  26 . 
   The control unit  22  can preferably be connected to the instruments, displays, control panels, units and instrument via a CAN bus. 
   Since the control unit  22  and the flowmeters  21  detect only the change in the inclination angle  15  of the trimming flaps  12 ,  13 , an initial position of the trimming flaps  12 ,  13  must first of be determined when the system is being started up. 
   This can be done on the one hand by storing the last position of the trimming flaps  12 ,  13 . However, the trimming flaps  12 ,  13  are preferably moved to one of the two limit positions of starting up the watercraft  10 , thus redefining the reference value or the initial position. 
   Furthermore the trimming flaps are preferably moved to the upper limit position automatically when the or each motor is switched off, and are in this way calibrated. 
   As described above, a trimming curve ( 28 ) can be used for automatic control of the inclination angles ( 15 ) of the trimming flaps ( 12 ,  13 ), and is preferably stored in the control unit ( 22 ). The trimming curve ( 28 ) can be indicated on the display ( 25 ) and can be varied by the control panel ( 26 ). Alternatively, a PC or laptop can also be connected to the control unit ( 22 ) or to some other point in the system in order to read the trimming curve ( 28 ) which is stored in the system, to edit it and to transmit it to the system again, with the aid of a suitable program. 
   Furthermore, it is also possible to provide for the capability for the trimming curve ( 28 ) also to be stored by the PC or laptop on a data storage medium. This allows different trimming curves ( 28 ) to be kept available, which can be played back to the system as required. On the other hand, the trimming curves ( 28 ) which are created manually using the control panel ( 26 ) can be saved on the PC, laptop or data storage medium. 
   By way of example, the PC or laptop can be connected with the aid of a serial cable. 
   Up to 50 values (increase in speed in knots and inclination angle ( 15 ) in degrees) can be entered in an appropriate table, and can be processed further, by means of the PC or laptop keyboard. The data which is  35  entered is preferably also displayed graphically. 
   During the downloading of the trimming curve ( 28 ) to the PC or laptop, the data relating to the trimming curve ( 28 ) is displayed as a table and graphically on an appropriate user interface, while the data can be processed further by the user. A progress bar is overlaid during the transmission process. 
   During uploading of the trimming curve ( 28 ), the successful procedure is signaled by confirmation on the user interface. Once again, a progress bar is overlaid during the transmission process. 
   
     
       
             
           
             
             
           
         
             
                 
             
             
               List of reference symbols: 
             
             
                 
             
           
           
             
                 
             
           
        
         
             
               10 
               Watercraft 
             
             
               11 
               Stern 
             
             
               12 
               Starboard trimming flap 
             
             
               13 
               Port trimming flap 
             
             
               14 
               Joint 
             
             
               15 
               Inclination angle 
             
             
               16 
               Plane 
             
             
               17 
               Hydraulic cylinder 
             
             
               18 
               Hydraulic system 
             
             
               19 
               Hydraulic unit 
             
             
               20 
               Hydraulic line 
             
             
               21 
               Flowmeter 
             
             
               22 
               Control unit 
             
             
               23 
               Line 
             
             
               24 
               Voltage supply 
             
             
               25 
               Display 
             
             
               26 
               Control panel 
             
             
               27 
               GPS receiver 
             
             
               28 
               Trimming curve 
             
             
               29 
               Instrument 
             
             
               30 
               Transom