Patent Publication Number: US-2015080069-A1

Title: Arrangement for Loss Measurement in a Combine Harvester

Description:
RELATED APPLICATIONS 
     This application claims priority under 35 USC §119 from DE 102013214984.0 which was filed on Jul. 31, 2013. 
     FIELD OF THE INVENTION 
     The invention pertains to an arrangement for loss measurement in a combine harvester, with a grain flow sensor for detecting the intensity of a grain stream separated out in a separating apparatus of a combine harvester and a monitoring unit for calculating a grain loss value on the basis of signals from the grain flow sensor. 
     BACKGROUND OF THE INVENTION 
     Combine harvesters are used for harvesting grain and other seeds. Plants standing or lying on a field are cut off or picked up by a harvesting head and transported by means of an inclined conveyor into the interior of the combine harvester. There the plants are threshed and fed to a separating system. Grain separated out in the separating process is cleaned in a cleaning system and temporarily deposited in a grain tank in order to be subsequently loaded into a transport vehicle. 
     The threshing process is usually carried out by means of a tangential threshing drum or in the threshing section of an axial threshing and separating rotor. The separating process is usually carried out by means of separating drums and a straw shaker of a tangential multi-drum threshing unit or by means of a separating rotor situated downstream of a tangential threshing mechanism, or in the separating section of an axial threshing and separating rotor. At the end of the separating process, the threshed straw is either deposited as a swath on the field, to be picked up and pressed into bales by a baler, or is directed through a straw chopper, in order to then be spread onto the field. 
     A certain amount of grain remains in the straw and is ejected onto the field. This causes undesired losses that reduce the yield and also result in subsequent vegetation due to sprouting grain. It is therefore desirable to detect the amount of lost grain in the straw at the end of the separating process in order to take countermeasures if necessary, such as a reduction of the travel speed or a modified setting of the threshing and/or separating equipment. In the prior art, a baffle plate sensor, which detects the noise generated by the impact of lost grain, was installed for this purpose at the rear end of the straw shaker (DE 24 48 745 A1). It is considered disadvantageous in this case that the measurement values are relatively imprecise, because the number of detectable grains is relatively small if the combine harvester has been properly adjusted and is operating properly, and the grains are largely embedded in the straw and are therefore not detected by the baffle plate sensor. Therefore a calibration is usually initially performed, in which the indicated values of a loss indicator device and the actual losses on the field are detected, e.g. by means of a loss testing bowl, and the user then travels at a speed that leads to an acceptable loss. 
     As a solution to this problem, U.S. Pat. No. 4,951,031 proposes equipping the threshing and separating apparatus with a plurality of grain flow sensors that detect the respective quantity of separated grains at each of the positions along the path of the crop though the threshing and separating apparatus. A separation curve is calculated based on the measurement values, in order to be able to recognize situations in which a high proportion of grain is separated in the rear area of the separating apparatus. Based on experience, there are also high losses in these situations, because the straw in the rear part of the separating apparatus still contains a relatively large amount of grain, which is finally ejected onto the field, at least in part. A similar arrangement is found in DE 101 62 354 A1. Because of the limited dimensions of the grain flow sensors in this case, they detect only relatively small portions of the grain, which are not always representative enough to supply sufficiently precise indications of losses. 
     The problem addressed by the present invention is considered to be that of providing a loss measurement arrangement in a combine harvester that does not have the above problems or has them only to a limited extent. 
     This problem is solved according to the invention by the teaching of the independent claim (or claims), while characteristics that further develop the invention in an advantageous manner are specified in the additional claims. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the invention, an arrangement for loss measurement in a combine harvester comprises a grain flow sensor for detecting the intensity of a grain stream separated out in a separating apparatus of a combine harvester and a monitoring unit for calculating a grain loss value on the basis of signals from the grain flow sensor. The grain flow sensor is associated with a conveying apparatus for grain arranged between the separating apparatus and a cleaning apparatus. 
     The conveying apparatus collects the material (grain) separated by the separating apparatus and transports it to the cleaning apparatus. The grain flow sensor is located in a section of the path of the material through the conveying apparatus. The grain flow sensor thus detects the collected material that is conveyed by the conveying apparatus from the separating apparatus. This has the effect that the grain flow sensor is exposed to a larger material flow than in the prior art, in which the sensor detects only the losses at the outlet of the separating apparatus or only a material stream striking it directly from the separating apparatus. Thus a stronger and more reliable signal is provided by the grain flow sensor, which allows the determination and display of a more reliable loss value than previously. 
     The grain flow sensor can detect the grain flow downstream of the conveying apparatus or inside the conveying apparatus. More particularly, it can be arranged downstream of or inside a conveyor bottom or a return pan of the separating apparatus. The separating apparatus can comprise a straw shaker or a separating rotor. 
     The monitoring device is preferably connected to a total grain flow sensor for detecting the total grain flow in the combine harvester, and determines the grain loss value on the basis of the signals from the grain flow sensor and the total grain flow sensor. For this purpose, loss curves or tables corresponding to different total grain flows, on the basis of which the monitoring unit can determine the respective loss for a given grain stream, can be stored in the monitoring unit. 
     In accordance with another aspect of the invention, an arrangement for loss measurement in a combine harvester ( 10 ,  10 ′) is provided, comprising a grain flow sensor ( 68 ,  68 ′,  68 ″,  68   a,    68   b ) for detecting an intensity of a grain flow separated in a separating apparatus of the combine harvester ( 10 ,  10 ′); and a monitoring device ( 74 ) for calculating a grain loss value on a basis of signals from the grain flow sensor ( 68 ,  68 ′,  68 ″,  68   a,    68   b ); wherein the grain flow sensor ( 68 ,  68 ′,  68 ″,  68   a,    68   b ) is associated with a conveying apparatus arranged between the separating apparatus and a cleaning apparatus ( 46 ). 
     The grain flow sensor may be configured to detect the grain flow downstream of the conveying apparatus or inside the conveying apparatus. 
     The grain flow sensor may be arranged downstream or inside a conveying floor ( 42 ) or a return pan ( 70 ) of the separating apparatus. 
     The separating apparatus may comprise a straw shaker or a separating rotor. 
     The monitoring device may be connected to a total grain flow sensor ( 78 ) for detecting a total grain flow in the combine harvester ( 10 ,  10 ′) and maybe operable to determine the grain loss value based upon a signal from the grain flow sensor ( 68 ,  68 ′,  68 ″,  68   a,    68   b ) and a signal from the total grain flow sensor ( 78 ). 
     The monitoring device may be connected to two grain flow sensors ( 68 ,  68 ′,  68 ″,  68   a,    68   b ) arranged at different points of the conveying apparatus and may be operable to determine a separation curve based upon signals from the two grain flow sensors ( 68 ,  68 ′,  68 ″,  68   a,    68   b ) and to generate a loss value based upon the separation curve. 
     In accordance with another aspect of the invention, a combine harvester comprises a threshing device, a separating apparatus, a cleaning apparatus ( 46 ) and an arrangement for loss monitoring. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Two embodiments of the invention, to be described below, are shown in the drawings, in which: 
         FIG. 1  shows a schematic side view of a first embodiment of a combine harvester with an arrangement for loss measurement according to the invention. 
         FIG. 2  shows a schematic side view of a second embodiment of a combine harvester with an arrangement for loss measurement according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a self-propelled combine harvester  10  with a frame  12  that is supported on the ground via driven front wheels  14  and steerable rear wheels  16  and propelled thereby. The driven front wheels  14  are driven by drive means, not shown in detail, in order to move the combine harvester  10 , for example, on a field to harvested. Directional indications such as front and rear refer below to the travel direction V of the combine harvester  10  during harvesting operation. 
     A crop uptake device  18  in the form of a cutting mechanism is removably connected to the front end area of the combine harvester  10 , in order to harvest crop in the form of grain or other threshable crops from the field and feed it upwards and to the rear by means of an inclined conveyor  20  to a multi-drum threshing mechanism that comprises—arranged in succession in the travel direction V—a threshing drum  22 , a stripper drum  24 , an overshot drum conveyor  26 , a tangential separator  28  and a turning drum  30 . Downstream of the turning drum  30  is a straw shaker  32  with a plurality of straw walkers arranged laterally one next to the other. In its lower and rear area, the threshing drum  22  is surrounded by a threshing basket  34 . Underneath the conveyor drum  26  is a cover  35  with a contiguous surface or furnished with openings, while above the conveyor drum  26  is a fixedly mounted cover, and a separating basket  36  with adjustable finger elements is located underneath the tangential separator  28 . A finger rake  38  is arranged underneath the turning drum  30 . 
     A front conveying floor  40 , which carries out an oscillating movement directed alternately to the front and the rear when in operation, is located underneath the multi-drum threshing mechanism. A rear conveying floor  42  is located underneath the straw shaker  32  and likewise carries out an oscillating movement directed alternately to the front and the rear. The front conveying floor  40  transports the mixture of grain and chaff passing through the threshing basket  34  and the separating basket  36  of the tangential separator  28  to the rear, while the rear conveying floor  42  transports the mixture of grain and chaff passing through the straw shaker  32  to the front. The rear conveying floor  42  transfers its mixture at its front end to the front conveying floor  40 , which outputs downward through a rear finger rake  44 . The mixture output by the front conveying floor  40  then reaches a cleaning apparatus  46 . 
     The grain cleaned by the cleaning apparatus  46  is fed by means of a screw auger  48  to an elevator, not shown, which conveys it into a grain tank  50 . A return auger  52  passes unthreshed head parts through an additional elevator, not shown, back into the threshing process. The chaff can be ejected at the rear side of the screen device by a rotating chaff distributor, or it is ejected by a straw chopper (not drawn) arranged downstream of the straw shaker  32 . The cleaned grain can be unloaded from the grain tank  50  by a discharge system with cross augers  54  and a discharge conveyor  56 . 
     The above-mentioned systems are driven by means of an internal combustion engine  58  and are monitored and controlled by an operator from a driver&#39;s cab  60 . Various apparatuses for threshing, conveying, cleaning and separating are located inside the frame  12 . An outer shell, which can be largely folded open, is located outside the frame  12 . 
     It must be noted that the multi-drum threshing mechanism presented here is only one example of an embodiment. It could also be replaced by a single transversely oriented threshing drum and a downstream separating apparatus with a straw shaker or one or more separating rotors. 
     The cleaning apparatus  46  comprises a fan  62 , which is composed of a rotor  64  that can be set into rotation (counterclockwise in  FIG. 2 ) and a housing  66  surrounding the rotor  64 . The cleaning apparatus  46  further comprises a pre-cleaning screen  72  with screen blades supported in a screen frame and mounted movably at an angle about their longitudinal axis, the screen being located underneath the rear finger rake  44  and extending nearly horizontally and slightly upwards from the rear edge of the front conveying floor  40 . 
     Underneath the front half of the pre-cleaning screen  72  is a conveying floor  80 , below which the upper part of the housing  66  for the fan  62  is arranged. To the rear of the conveying floor is a grating  96 , which is followed by an upper screen  90  and a lower screen  92  arranged thereunder. The upper screen  90  and the lower screen  92  each comprise screen blades arranged in a frame and are adjustable independently of one another at an angle about their longitudinal axis. Further details regarding the cleaning apparatus  46  can be found in DE 10 2005 026 608 A1. Any other desired cleaning apparatus can also be used. In particular, the pre-cleaning screen  72  can be replaced by a conveying floor or a conveyor auger. 
     In order to determine the losses in the separating unit, which is formed in the embodiment of  FIG. 1  by the tangential separator  28  and the straw shaker  32 , a grain flow sensor  68  is provided, which is located underneath the front end of a return pan  70  that is located underneath the rear area of the straw shaker  32  and is used to convey grain separated there to the rear conveying floor  42 . The grain flow sensor  68  is located inside a winnowing step through which the grain passes between the return pan  70  and the rear conveying floor  42 . Impacting grains cause easily detectable vibrations on the grain flow sensor  68 , which can be configured as a conventional baffle plate sensor. 
     An additionally or alternatively provided grain flow sensor  68 ′ is located inside the rear conveying floor  42 , more particularly, roughly at the beginning of the rear third. The grain flow sensor  68 ′ lies in the plane of the rear conveying floor  42  and detects vibrations caused by grains impacting it during the conveying process. It can likewise be constructed as a baffle plate sensor. 
     An additionally or alternatively provided grain flow sensor  68 ″ is located inside a winnowing step through which the grain passes between the rear conveying floor  42  and the front conveying floor  40 . 
     Impacting grains cause easily detectable vibrations on the grain flow sensor  68 ″, which can likewise be configured as a conventional baffle plate sensor. 
     The grain flow sensors  68 ,  68 ′ and/or  68 ″ are connected so as to transmit signals to a monitoring device  74 , which is in turn connected to a display device  76 . The monitoring device  74  is also connected to a total grain flow sensor  78 , which is associated in the illustrated embodiment with the screw auger  48  and detects its drive torque. In a different embodiment, the total grain flow sensor  78  could detect the grain flow by photoelectric barriers in the grain elevator (not shown), which is located between the screw auger  48  and the grain tank  50 . 
     During harvesting operation, the monitoring device  74  receives signals from one or more of the grain flow sensors  68 ,  68 ′ or  68 ″. These signals are generated by a relatively large integrated upstream and downstream flow of grain through the return pan  70  and the rear conveying floor  42  or inside the rear conveying floor  42  and are therefore quite reliable. Signals regarding the grain separated in the rear third (grain flow sensor  68 ) or in the rear two thirds (grain flow sensor  68 ′) or in the entire straw shaker  32  (grain flow sensor  68 ″) are thus applied to the monitoring device  74 . These signals are calculated by the monitoring device  74  into loss values. For this purpose, loss curves associated with different overall grain flows detected by the total grain flow sensor  78  can be called up from the memory of the monitoring device  74 , and the current loss value for the signal of the grain flow sensor ( 68 ,  68 ′ or  68 ″) can be read out from the respective applicable loss curve and displayed on the display device  76 . Alternatively or additionally, the monitoring device  74  can be connected to two grain flow sensors arranged at different points in the conveying apparatus (e.g.  68  and  68 ′ and/or  68 ″, or  68 ′ and  68 ″) and a separation curve can be generated on the basis of the signals of the different grain flow sensors, and a loss value can be generated on the basis of the separation curve. The reader is referred to the prior art from U.S. Pat. No. 4,951,031 A and DE 101 62 354 A1 in this regard. 
     It would also be conceivable to further connect the monitoring device  74  to conventional loss sensors for the cleaning, in order to also be able to display cleaning losses (and/or a cumulative loss value) on the display device  76 . 
     In the embodiment of the combine harvester  10 ′ according to  FIG. 2 , elements corresponding to the first embodiment are labeled with the same reference numbers. The essential difference is that the multi-drum threshing mechanism with the downstream straw shaker  32  was replaced by an axial threshing and separating rotor. The crop material is fed by the inclined conveyor  20  to a conveying drum  122 , which feeds the crop material in an overshot manner to an inlet transition section  124  of the axial threshing and separating rotor. A threshing section  126  and a separating section  128  of the axial threshing and separating rotor follow the inlet transition section  124  in the downstream direction. The threshed straw is ejected by an ejection drum  130  or supplied to a straw chopper (not shown). The reader is referred to EP 2 055 176 A1 for further details. 
     A threshing basket  132  is arranged underneath the threshing section  126 , and a separating grating  134  is arranged underneath the separating section  128 . A screw conveyor  140  conveys the grain falling downwards through the threshing basket  132  to the rear and onto the pre-cleaning screen  72 , while the rear conveying floor  42  conveys the crop falling downwards through the separating grating  134  and outputs it to the pre-cleaning screen  72  in a winnowing step, in which a grain flow sensor  68   a  is arranged. An additional or alternative grain flow sensor  68   b  is mounted in the rear third of the rear conveying floor  42 , analogously to the grain flow sensor  68 ′ of  FIG. 1 . 
     In this embodiment, the grain flow sensor  68   a  thus detects the entire grain flow separated by the separating apparatus, which is formed by the separating section  128  and the separating grating  134 . The grain flow sensor  68   b  approximately detects the grain flow separated in the rear third of the separating apparatus. The mode of operation of the arrangement for loss measurement with the monitoring device  74 , the display device  76 , the grain flow sensor  68   a  and/or  68   b  and the total grain flow sensor  78  corresponds to that of the embodiment according to  FIG. 1 .