Patent Publication Number: US-2010122632-A1

Title: Arrangement and Process For The Wrapping Of A Bale

Description:
FIELD OF THE INVENTION 
     The invention concerns arrangements and processes for the wrapping of agricultural bales. The arrangement has a drive for the introduction of a wrapping material into a baling chamber, a sensor for the detection of a physical size of a bale being formed in the baling chamber, and a control arrangement connected to the drive and the sensor that can be operated so as to activate the drive based on the signals from the sensor. 
     BACKGROUND OF THE INVENTION 
     Round agricultural balers are usually equipped with arrangements for the wrapping of the finished bale that are brought into movement by a drive, and deliver twine, a net or a foil, that is deposited upon and envelops the rotating bale. Such arrangements are only activated after the completion of the bale, and can be induced by the operator by means of an input arrangement, after the operator has been notified by a signal in a display arrangement that the size of the bale or the density of the bale has reached a certain value. It has also been proposed that the drive of the arrangement for the wrapping of the bale be activated automatically, as soon as the sensor for the detection of the size of the bale indicates that the desired diameter of the bale had been reached (U.S. Pat. No. 5,551,218, EP1813146A2). 
     SUMMARY OF THE INVENTION 
     In the case of an actuation of the arrangement for the wrapping of a bale based upon the size of the bale it is seen as detrimental that a certain time delay occurs between the actuation of the drive and the beginning of the actual wrapping process, that is occasioned by the distance between the arrangement and the baling chamber and the conveying velocity of the drive. This time delay slows the bale manufacturing process. 
     The problem underlying the invention is thus seen in the need to make available an arrangement improved over the state of the art for the wrapping of a bale that is not subject to the aforementioned disadvantages or does so to a lesser degree. 
     An arrangement for wrapping a bale in a round agricultural baler having a baling chamber of a fixed or variable bale size includes a drive, with which wrapping material can be introduced into the baling chamber, in order to wrap the finished bale located in the baling chamber. The wrapping material in particular, may be twine, net or foil. 
     Moreover, the arrangement includes a sensor that detects the physical size of the bale developing in the baling chamber, which may be a size d in the radial direction (Diameter or radius or the like) or the density p. The sensor can detect the dimension d in the radial direction directly, in which, for example, the bale is scanned by a feeler or by waves, or indirectly, in that, for example, a sensor detects the amount of harvested crop entering the baling chamber that is successively integrated upward in a calculating arrangement. Analogously the density p of the bale can be detected by appropriate sensors in the side walls of the baling chambers (see EP0634094A1) or on the basis of the pressure in the cylinder that opens the back door of the baler (compare EP1593299A1 and the state of the art cited there) or indirectly in that, for example, a sensor is used to detect the amount of harvested crop entering the baling chamber that is successively integrated upward in a calculating arrangement. 
     An electronic control arrangement is connected with the drive and the sensor. During the baling operation the control arrangement detects the growth rate Δd/Δt or Δp/Δt of the size of the bale that is the actual change in the size per unit of time. In addition, the control arrangement has available information regarding the time delay t 1  between the activation of the drive and the time at which the wrapping material reaches the baling chamber and that depends on the conveying velocity of the drive and the distance between the forward end of the wrapping material and the baling chamber. The control arrangement activates the drive looking ahead at the exact time before the bale has reached the desired size, in order to assure that the wrapping material reaches the baling chamber exactly at the time at which the size of the bale corresponds to the desired size. Accordingly the control arrangement activates the drive at a growth rate Δd/Δt, a time delay t 1  and a target size of the bale of d target  as soon as the diameter d is equal to the equation d=d target −t 1 ×Δd/Δt (for example, at a growth rate of the density Δp/Δt, a time delay t 1  and a target density of the bale of p target  as soon as the density is equal to the expression p=p target −t 1 ×Δp/Δt). 
     In this way, undesired time delays in the supply of the wrapping material to the baling chamber are avoided. 
     In a preferred embodiment of the invention the control arrangement is supplied with information regarding the actual forward propulsion velocity that can be detected by a sensor located on board the baler or the towing vehicle. However, the forward propulsion velocity may also be a target value that has been stored in the drive control arrangement of the towing vehicle and is transmitted to the control arrangement over a data bus (CAN or ISO BUS). 
     The growth rate of the bale Δd/Δt or Δp/Δt can be determined on the basis of the signals of the sensor for the detection of the size or the density of the bale that is growing in the baling chamber. Alternatively or additionally a further sensor is used to detect the amount of the harvested crop entering the baling chamber, that can be fastened, for example, to the tow bar or the underside of the baler and determines the contour of the swath that is to be picked up upstream of the pickup of the baler by means of optical waves (laser distance measurement) or acoustic waves (ultrasound waves). The incoming amount of material can also be detected optically or mechanically by an appropriate probe, or by monitoring the drive torque of the pickup or of a rotor following it downstream. Alternatively or additionally the incoming amount of material is derived from existing yield data that has been detected during a previous operating cycle (mowing or swaths) by means of appropriate sensors, geo-referenced and stored in memory and made available to the control arrangement. 
     The information regarding the actual forward operating velocity in turn is used by the control arrangement for the exact determination of the rate of growth Δd/Δt or Δp/Δt of the size of the bale, if the forward propulsion velocity is not constant. In the individual case an average change in the size of the bale can be calculated for this and referenced to the path length x for the change in the size of the bale Δd/Δx or Δp/Δx multiplied by the immediate forward velocity v, in order to determine the growth rate Δd/Δt or Δp/Δt in the size of the bale. The average change in size of the bale referenced to the path length can be determined continuously from the growth rates and associated forward propulsion velocities described in the previous paragraph. 
     During the wrapping process of the bale and its following ejection, the baler should not move forward (as long as this is not a continuously operating baler with a pre-chamber, in which the incoming harvested crop is stored temporarily during the wrapping process) in order to prevent that additional harvested crop intrudes into the baling chamber. Therefore the invention proposes that the control arrangement be connected to a display arrangement that is associated with the operating stand of the operator of the towing vehicle (or a self-propelled baler). On this display arrangement the operator is advised to stop the towing vehicle as soon as the wrapping process has begun. Alternatively or additionally the control arrangement is connected with a velocity input arrangement of the towing vehicle in order to induce the latter to stop the baler automatically at the beginning of the wrapping process. 
     Some wrapping materials (especially twine) are entangled more easily in the bale, if harvested crop still enters the baling chamber at the beginning of the wrapping process. Therefore the invention proposes that the drive and the display arrangement and/or the velocity input arrangement on the towing vehicle be controlled in such a way that harvested crop continues to enter the baling chamber when the beginning end of the wrapping material enters into the baling chamber. As soon as the wrapping material has been grasped by the bale, however, the baler is stopped by the control arrangement in the aforementioned manner. In the case of other wrapping materials (net or foil) however, the baler is stopped by the control arrangement when the drive is activated for the first time. 
     In a possible embodiment of the invention the control arrangement activates the drive at the exact time selected in this way so that the wrapping material reaches the baling chamber exactly when the size of the bale equals the desired size and permits it to continue running automatically until the bale has grasped the wrapping material which can be detected by an appropriate sensor and transmitted to the control arrangement which then stops the drive. Accordingly the introduction of the wrapping material has been completely automated. 
     On the other hand, another embodiment provides that the control arrangement activate the drive automatically until the wrapping material is located immediately ahead of the baling chamber, but has not yet been grasped by the bale. Subsequently the drive is activated only upon an operator&#39;s input in an operator&#39;s input arrangement, until the bale has grasped the wrapping material which is recognized by means of an appropriate sensor and transmitted to the control arrangement which then turns off the drive. Accordingly an operator&#39;s control exists for the initiation of the actual wrapping process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings show an embodiment of the invention that shall be described in greater detail in the following: 
         FIG. 1  is a schematic side view of a towing vehicle and a round baler with an arrangement for the wrapping of a bale; and, 
         FIG. 2  is a flow chart according to which the control of the arrangement operates. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a round baler  10  with a housing  12 , that can be coupled by means of a tow bar  14  to a towing vehicle  50  in the form of an agricultural tractor, in order to be towed across a field in a direction of operation to the right in  FIG. 1 , and is supported on wheels  16 . The housing  12  is composed of a forward rigid housing half  18  and a rear housing half  20  that can be pivoted, these are connected to each other so they can pivot by a joint  19  located upward. The housing  12  carries a multitude of rolls. Several endless conveying elements  22 , arranged alongside each other, extend over the rolls and largely surround the baling chamber  24  that is also enclosed by side walls of the housing  12 . In this embodiment the conveying elements  22  are configured as belts. An inlet  26  is provided in the lower region of the baling chamber  24 , which is bordered to the rear by a roll  28  and permits entry into the baling chamber  24  by crop taken up by a pickup  30 . 
     The round baler  10  includes several conveying elements  22  arranged alongside each other. They are brought into movement during the harvesting operation and enclose a bale  32  being formed in the bailing chamber  24  to the front, above and to the rear. The configuration and the functions of such a round baler are known in themselves. Reference is made to the disclosure of DE 10153540A whose contents are included by reference in the present document. Bales of increasing diameter are characterized by call-outs  32 ,  32 ′,  32 ″. 
     A sensor  34  is fastened to the upper rear end of the rear housing half  20  that can be pivoted. The sensor  34  is an ultrasonic distance measuring device that is based on a measurement of running time and detects the spacing between its underside and the adjoining conveying elements  22  that are located directly in contact with the outer circumference of the bale  32 . In this way the sensor  34  makes available information regarding the diameter of the bale  32 . 
     Moreover, the round baler  10  includes a first wrapping material dispenser  44  that is arranged on the rear side of the pivoted rear housing half  20 . The wrapping material dispenser  44  includes a supply  46  of wrapping material, that consist of a rolled up net or a foil, whose forward unrolled end is conducted through pairs of rolls  48 . The rolls  48  can be brought into rotation by a drive  54  so that the forward end of the wrapping material is drawn along by the conveying devices  22  when the drive  54  is activated, and reaches the baling chamber  24  and there encloses the bale  32 . A free section (not shown) is arranged between the drive  54  and the rolls  48 , so that the bale  32  can draw off the wrapping material from the supply  46  without rotating the drive  54  with it. In addition, the first wrapping material dispenser  44  includes a separating arrangement  56  in order to cut off the wrapping material after the wrapping process. 
     A second wrapping material dispenser  58  is located on the forward side of the round baler  10  and includes a supply  60  of wrapping material that consists of twine. The second wrapping material dispenser  58  includes a pair of rolls  64  that can be driven by means of a drive  62 , in order to introduce the wrapping material into the baling chamber  24 , so that it is carried along there by the bale  32  and encloses it. The wrapping material is successively conducted across the width of the bale  32 , in that the entire wrapping material dispenser  58  or an outlet opening is continuously moved sideways. A free section (not shown) is arranged between the drive  62  and the rolls  64 , so that the bale  32  can withdraw the wrapping material during the withdrawal from the supply  60 , without rotating the drive  62  along with it. In addition, the first wrapping material dispenser  44  includes a separating arrangement (not shown) in order to be able to cut off the wrapping material after the wrapping process. 
     The sensor  34  is connected with a control arrangement  38  over a bus, that in turn controls a display arrangement  40  in the operator&#39;s cab  52  of the towing vehicle  50  and receives instruction from an input arrangement  42  also located there. In addition, the control arrangement  38  is connected with the drives  54 ,  62 , a velocity input arrangement  66  (motor- and gearbox control) of the towing vehicle  50 , a velocity sensor  68  in the form of a rotational speed sensor to detect the rotational speed of the wheels  16  and a throughput sensor  70  that is mounted on the underside of the tow bar  14  and that scans the swath that is to be taken up by the pickup  30  optically or with ultrasonic waves in order to determine its volume. 
       FIG. 2  shows the function of the control arrangement  38  on the basis of a flow chart. After the start in step  100  the operator is induced in step  102  by the display of an appropriate text on the display arrangement  40  to select the wrapping material, for the purpose of which corresponding options can be selected by means of the input arrangement  42  (no wrapping material, twine and foil or net, depending on the supply  46  located in the first wrapping material dispenser). In addition, the desired bale diameter d target  is provided as input in the input arrangement  42 . 
     The process originates from the fact that the towing vehicle  50  tows the baler  10  across a field and the latter continuously takes up harvested crop and forms it into a bale  32 . The velocity of the towing vehicle  50  may be provided as input by the operator or controlled automatically. For this purpose reference is made to EP 1813146A2 whose disclosure is incorporated by reference into the present document. In the next step  104  the diameter of the bale  32  is determined on the basis of the signals of the sensor  70 . Then step  106  follows in which an average change in size of the bale is referenced to the length of the path x (Δd/Δx). Here reference is made to the signals of the sensor  34 , the velocity sensor  68  and (optionally) of the through put sensor  70 . This change in size is averaged over a last distance covered of several meters. It would also be conceivable to store a yield card in the control arrangement  38  and to recall the distance covered on the basis of the actual position that is detected by an antenna  72  for the reception of signals of a satellite based position detection system. 
     Following this, step  108  questions whether a wrapping process is contemplated. If that is not the case, step  110  follows, in which the question is posed whether the actual diameter d of the bale  32  is equal to the desired diameter d target . If that is not the case step  104  again follows, otherwise step  112  is used, in which the towing vehicle  50  is stopped as described further in the following, and then the bale  32  has been ejected. Subsequently the towing vehicle  50  resumes the forward operation in order to create further bales  32 . Then step  100  again follows, although step  104  could follow directly. 
     In case step  108  indicates that a wrapping process is intended the control arrangement  38  then determines in the following step  114  whether the size of the bale has reached a value that would lead to a looking ahead activation of one of the drives  54  or  62 . For this purpose the actual bale size d is compared with the difference of the desired bale diameter d target  and the product of the time delay t 1  which is compared with the growth rate of the size of the bale Δd/Δt that is calculated by multiplying the velocity v with the average growth rate of the bale Δd/Δx referenced to the path length x (t 1  is the time delay between the activation of the drive  54  or  62  and the exact time at which the wrapping material reaches the baling chamber  24 ). Here, in each case, the time delay t 1  associated with the particular wrapping material dispenser  44  or  58  selected should be used in step  102 . 
     In case that a diameter d has not yet been reached, which requires an activation looking ahead of one of the drives  54  or  62 , step  104  again follows. Otherwise, step  116  follows, in which the question is posed, whether the second wrapping material dispenser  58  had been selected in step  102 . If that is the case, the drive  62  is activated in step  118 , in order to insert the wrapping material (twine) into the baling chamber  24 . The subsequent step  120  determines whether the wrapping material has been grasped, that is, the free space between the rolls  64  and the drive  62  is running freely and the wrapping material is withdrawn from the supply  60  that can be detected by a sensor (not shown) on one of the rolls  64 . If that is the case, step  122  follows, otherwise step  120  repeats again. In the following step  122  the towing vehicle  50  is stopped, which can be performed either by the operator who is advised by a corresponding display on a display arrangement  40  or automatically, in that velocity input arrangement  66  of the towing vehicle  50  is instructed correspondingly. Accordingly the towing vehicle  50  is first stopped (and the flow of harvested crop in the baling chamber  24  is stopped), when the wrapping material has been grasped by the bale  32  and carried along. In the following step  124  the question is posed whether the bale  32  has been wrapped completely, that is, a desired number of layers of wrapping material have been applied. If that is not the case, step  124  again follows, otherwise the wrapping material is cut off and step  112  follows. 
     In case that step  116  has shown that not twine, but foil or net is to be used as wrapping material, then step  126  follows upon step  116 , in which the drive  54  is activated and the towing vehicle  50  is stopped, this can be performed either by the operator who is advised correspondingly by the display arrangement  40 , or automatically, in that the velocity input arrangement  66  of the towing vehicle  50  is instructed correspondingly. The subsequent step  128  determines whether the wrapping material has been grasped, that is, the free running space between the rolls  48  and the drive  54  is running freely and the wrapping material is withdrawn from the supply  46 , which can be detected by means of an appropriate rotational speed sensor (not shown) on one of the rolls  48 . If that is the case, step  124  follows, otherwise step  128 . 
     The activation of the drives  54  or  62  that is looking ahead has the advantage that the wrapping process begins as soon as the bale  32  has reached its desired bale diameter d target . Therefore the operating process is not delayed unnecessarily by the time delay between the activation of the drives  54  or  62  and the arrival of the forward end of the wrapping material in the baling chamber  24 . It should be noted that the order of the steps  126  and  128  could also be reversed. In addition it would be possible to activate the drives  54  or  62  in steps  118  and  126  only so long as the front end of the wrapping material is located directly in front of the baling chamber  24  and then to indicate on the display arrangement  40  whether the wrapping process should now be started. The operator can then bring about a wrapping of the bale  32  without any delays by an input in the input arrangement  42 . 
     It should be noted, that the present invention can be applied not only to the round baler  10  described above with variable baling chamber size, but also to a round baler, not shown, with a fixed baling chamber size. In the latter case the actual density p of the bale in the baling chamber is detected by appropriate sensor technology along with the growth rate of the density Δp/Δt. There the drive for the introduction of the wrapping material into the baling chamber on the basis of the growth rate, the time delay between the actuation of the drive and the exact time at which the wrapping material reaches the baling chamber and the actual density is activated, looking ahead. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.