combine

Abstract

To provide a combine-harvester which can suppress the degradation in a sorting performance depending on a farm field condition.SOLUTION: A value correlated to a reduction flow amount of a second object is detected by a second flow amount sensor 83. A target value of the reduction flow amount of the second object is set by a control device 91. The control device 91 controls a first chaff sieve and a fan of a sorting unit 22 such that the second reduction flow amount estimated from the detection value of the second flow amount sensor 83 matches the target value to change the opening degree of the first chaff sieve and the air volume of sorting wind by the fan.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a combine harvester. [Background technology]

[0002] In a combine harvester, crops planted in a field are harvested by a harvesting device, and the harvested crops are transported from the harvesting device to a thresher, where the grains are removed from the crop stalks, sorted, and transported to a grain tank.

[0003] In the threshing machine, specifically, culms are fed into the threshing chamber, and as the threshing drum rotates, the culms are transported from the supply side of the threshing chamber toward the discharge side, while the grains are removed from the culms. The grains that have been removed from the culms drop through a receiving net together with impurities such as broken culms, and fall as sorting objects onto, for example, the first chaff sieve and the second chaff sieve. A grain sieve is provided below the first chaff sieve. In the process of the sorting objects dropping onto the first chaff sieve and the process of the sorting objects dropping through the first chaff sieve and the grain sieve, the grains are sorted from the sorting objects, and the sorted first grains are transported to a grain tank. The sorting objects that do not leak through the first chaff sieve and remain on the first chaff sieve are transferred from the first chaff sieve to the second chaff sieve. During the process of the sorting objects falling onto the second chaff sieve and the process of the sorting objects leaking through the second chaff sieve, grains are sorted from the sorting objects, and the sorted second grains are returned to a position where they will fall onto the first chaff sieve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-7916 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the amount of crops supplied to the threshing device per unit time varies depending on the speed of the combine harvester during reaping, in conventional combine harvesters, the opening degree of the first chaff sieve and the air volume of the winnower are set according to the vehicle speed. In other words, the opening degree of the first chaff sieve and the air volume of the winnower are set to larger values ​​as the vehicle speed of the combine harvester during reaping increases. As a result, threshing (threshing and sorting) is performed at a processing speed according to the amount of crops supplied to the threshing device.

[0006] However, depending on the field conditions, the sorting performance of the thresher may deteriorate. For example, when crops in a field with a low yield are harvested at a high vehicle speed, the opening of the first chaff sieve is large relative to the amount of crop fed to the thresher, and this increases the proportion of impurities in the first grain.

[0007] An object of the present invention is to provide a combine harvester that can suppress deterioration of sorting performance due to field conditions. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the combine harvester of the present invention includes a threshing device that allows the sorting object, including grains and impurities obtained by threshing a crop in the threshing section, to leak into the sorting section, sorts grains from the sorting object in the sorting section and recovers the sorted No. 1 grains, sorts grains from the sorting object from which the No. 1 grains have been removed in the sorting section, and returns the sorted No. 2 grains to the sorting section, a No. 2 flow rate sensor that detects a value correlated with the return flow rate of the No. 2 grains, and a control device, and the control device sets a target value for the return flow rate and controls the sorting section so that the return flow rate obtained from the detection value of the No. 2 flow rate sensor matches the target value.

[0009] According to this configuration, the second flow rate sensor detects a value correlated with the return flow rate of the second crop. Meanwhile, the control device sets a target value for the return flow rate of the second crop. Then, the control device controls the sorting unit so that the return flow rate obtained from the detection value of the second flow rate sensor matches the target value. This adjusts the return flow rate of the second crop to the target value, thereby stabilizing the amount of sorting objects stored in the threshing device. As a result, the sorting objects can be sorted at a processing speed according to the amount of crops supplied to the threshing device, while suppressing deterioration of sorting performance due to field conditions.

[0010] The sorting section is equipped with a chaff sieve whose sorting amount of No. 1 material changes depending on its opening, and the control device may reduce the opening of the chaff sieve when the return flow rate obtained from the detection value of the No. 2 flow sensor is smaller than a target value, and may increase the opening of the chaff sieve when the return flow rate obtained from the detection value of the No. 2 flow sensor is larger than the target value.

[0011] In this configuration, the return flow rate of the second product can be adjusted to a target value by adjusting the opening of the chaff sieve.

[0012] The sorting section is equipped with a winnower that generates sorting air for winnowing the items to be sorted, and the control device may reduce the volume of the sorting air generated by the winnower when the return flow rate obtained from the detection value of the second flow sensor is smaller than a target value, and may increase the volume of the sorting air generated by the winnower when the return flow rate obtained from the detection value of the second flow sensor is greater than the target value.

[0013] In this configuration, the return flow rate of the second-grade rice can be adjusted to a target value by adjusting the volume of the sorting air generated by the winnower.

[0014] Since the appropriate chaff sieve opening and sorting wind volume vary for each crop, it is preferable that the control device set target values ​​for each crop.

[0015] The combine may further include an input device for inputting an instruction to change the target value, and the control device may change the target value in response to the instruction input from the input device.

[0016] This configuration allows the user to change the target value, and by doing so, it is possible to adjust the sorting process speed and sorting performance (the proportion of impurities contained in the first-class refinery).

[0017] The sorting section is equipped with a chaff sieve whose sorting amount of the second-order objects changes depending on its opening degree, and the control device may change the target value depending on the opening degree of the chaff sieve.

[0018] Since the amount of second-grade material sorted varies depending on the opening of the chaff sieve, the amount of material to be sorted stored in the threshing device can be kept stable by changing the target value according to the opening of the chaff sieve.

[0019] The combine harvester supports a body including the threshing device and further includes a pair of left and right traveling devices driven by power from a power source, and the control device may reduce the vehicle speed of the traveling devices when the chaff sieve is at its maximum opening and the return flow rate obtained from the detection value of the second flow sensor is greater than the target value by a predetermined amount or more.

[0020] This reduces the amount of crop supplied to the threshing device and reduces the return flow rate of the second crop, thereby preventing an increase in sorting losses.

[0021] The predetermined amount may be 0 or a value greater than 0. Effect of the Invention

[0022] According to the present invention, the return flow rate of the second crop is adjusted to a target value, so that the amount of the sorting objects stored in the threshing device is stabilized. As a result, the sorting objects can be sorted at a processing speed according to the amount of crops supplied to the threshing device, while suppressing deterioration of sorting performance due to field conditions. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a right side view of a combine harvester according to one embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] This is a cross-sectional view of the threshing device taken along a cutting plane along the front-to-back direction, viewed from the left. [Figure 4] FIG. 2 is a front view of the threshing device and the conveying device, together with the grain tank shown in cross section. [Diagram 5] 1 is a cross-sectional view of the conveying device taken along a cutting plane along the front-rear direction as viewed from the right. [Figure 6] This is a cross-sectional view of the threshing device taken along a cutting surface along the left-right direction. [Figure 7] FIG. 2 is a block diagram showing a main part of the electrical configuration of the combine harvester. [Figure 8] 13 is a flowchart showing a flow of a target value setting process. [Figure 9] 13 is a flowchart showing the flow of the second return flow rate control. [Figure 10] 4 is a flowchart showing a flow of vehicle speed control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0025] <Overall configuration of combine harvester> Fig. 1 is a right side view of a combine harvester 1 according to an embodiment of the present invention, and Fig. 2 is a top view of the combine harvester 1.

[0026] The combine harvester 1 is an agricultural machine that harvests and threshes crops while traveling in a field.

[0027] The combine harvester 1 employs a pair of left and right crawler traveling devices 2 as traveling devices capable of traveling over rough ground such as farm fields. A machine body frame 3 is supported by the left and right crawler traveling devices 2, and power from an engine 4 provided on the machine body frame 3 is transmitted to the crawler traveling devices 2 via a transmission 5.

[0028] In addition, a cabin 6, a threshing device 7, and a grain tank 8 are provided on the machine frame 3. A reaping device 9 that harvests crops is provided in front of the crawler traveling device 2 and the machine frame 3. A feeder 11 that transports crops harvested by the reaping device 9 to the threshing device 7 is provided between the threshing device 7 and the reaping device 9.

[0029] The cabin 6 is disposed on the front end of the vehicle frame 3. The cabin 6 provides a space within which a user boards, and within this space, for example, a driver's seat 12 in which the user sits, an operation lever 13 operated by the user, and the like are disposed. An openable door 14 is provided on the right side of the cabin 6, and the user can enter the cabin 6 by opening the door 14.

[0030] The threshing device 7 is disposed to the left rear of the cabin 6. The grain tank 8 is disposed to the rear of the cabin 6 and to the right of the threshing device 7. In the threshing device 7, grains are removed from the stalks of the crop transported by the feeder 11. A conveying device 15 is provided between the threshing device 7 and the grain tank 8, and the grains threshed by the threshing device 7 are transported from the threshing device 7 to the grain tank 8 by the conveying device 15 and stored in the grain tank 8. An unloader 16 is connected to the grain tank 8, and the grains stored in the grain tank 8 can be discharged from the grain tank 8 to the outside of the machine by the unloader 16.

[0031] <Threshing device> FIG. 3 is a cross-sectional view of the threshing device 7 taken along a cutting plane along the front-rear direction, as viewed from the left.

[0032] The threshing device 7 is equipped with a threshing section 21 and a sorting section 22.

[0033] The threshing section 21 includes a threshing chamber 23 provided at the top of the threshing device 7, a threshing drum 24 and a receiving net (concave) 25.

[0034] The handling chamber 23 is enclosed on the sides by a left side panel 31 (see FIG. 2), a right side panel 32, a front side panel 33, and a rear side panel 34, and is closed above by a top panel 35 and open below. Crops transported by the feeder 11 are fed into the handling chamber 23 through a crop feeding opening 36 formed in the front side panel 33.

[0035] The threshing drum 24 is housed in the threshing chamber 23 and is supported by a front side plate 33 and a rear side plate 34 so as to be rotatable about a rotation axis extending in the front-rear direction. The threshing drum 24 is provided with a number of threshing teeth 37 extending in the radial direction of rotation. As the threshing drum 24 rotates, the threshing teeth 37 thresh grains from the stalks of the crop put into the threshing chamber 23.

[0036] The receiving net 25 is provided below the threshing drum 24 so as to close the threshing chamber 23 from below. The receiving net 25 is formed in a semi-cylindrical shape along the circumferential direction of the threshing drum 24. The grains threshed from the stalks are received by the receiving net 25. The receiving net 25 has a lattice-like mesh, and the grains received by the receiving net 25 drop through the receiving net 25 together with impurities such as relatively small pieces of stalk.

[0037] The sorting section 22 includes a grain pan 42, a first chaff sieve 43, a second chaff sieve 44 and a grain sieve 45 within a sieve case 41 provided below the handling chamber 23.

[0038] The grain pan 42 is disposed at the front end of the sieve case 41. The first chaff sieve 43 is disposed rearward of the grain pan 42. The second chaff sieve 44 is disposed rearward of the first chaff sieve 43. The grain sieve 45 is disposed below the first chaff sieve 43.

[0039] The sorting section 22 is also provided with a winnower 46 that generates sorting wind. The winnower 46 is disposed below and in front of the sieve case 41, and the sorting wind generated by the winnower 46 passes through the sieve case 41 toward the rear.

[0040] The sorting objects, consisting of grains and impurities, that drop through the receiving net 25 of the threshing section 21 enter the sieve case 41 and drop onto the grain pan 42, the first chaff sieve 43 or the second chaff sieve 44. In order to transport and sieve the sorting objects, the sieve case 41 is swung, and the grain pan 42, the first chaff sieve 43, the second chaff sieve 44 and the grain sieve 45 are also swung.

[0041] The material to be sorted that has fallen onto the grain pan 42 is transported backward by the swinging of the grain pan 42 and separated into upper and lower layers of impurities with relatively low specific gravity and grains with relatively high specific gravity. The grains in the lower layer fall from above the grain pan 42 and are transported onto the first chaff sieve 43.

[0042] The first chaff sieve 43 is provided with a plurality of plate-shaped chaff flips 47 arranged in the front-rear direction. Each chaff flip 47 is configured to be swingable around an axis extending in the left-right direction, and the tilt angle is changed by the swing. By changing the tilt angle of each chaff flip 47, the interval between the chaff flips 47 increases or decreases, and the opening degree of the first chaff sieve 43 changes. By the swing of the first chaff sieve 43, the objects to be sorted on the first chaff sieve 43 are sieved and sorted while being transferred backward, and objects to be sorted that are smaller than the interval between the chaff flips 47 leak out between the chaff flips 47. In addition, objects to be sorted that have a smaller specific gravity than the grains are blown backward from above the first chaff sieve 43 by the sorting wind from the winnower 46.

[0043] The sorting objects leaking from the first chaff sieve 43 fall onto the grain sieve 45. During this falling process, the sorting objects are winnowed by the sorting wind from the winnower 46, and impurities with a lower specific gravity than the grains are blown backwards. The grain sieve 45 has, for example, a lattice-like mesh. The grain sieve 45 oscillates and sifts the sorting objects on the grain sieve 45, and sorting objects smaller than the mesh of the grain sieve 45 leak through the mesh. The sorting objects remaining in the grain sieve 45 are blown backwards by the sorting wind from the winnower 46.

[0044] The objects to be sorted remaining on the first chaff sieve 43 fall from the rear end of the first chaff sieve 43 onto the second chaff sieve 44. The second chaff sieve 44 has a plurality of plate-shaped chaff flips 48 arranged in the front-rear direction. Each chaff flip 48 is configured to be swingable around an axis extending in the left-right direction, and the inclination angle is changed by the swinging. By changing the inclination angle of each chaff flip 48, the interval between adjacent chaff flips 48 in the front-rear direction increases or decreases, and the opening degree of the second chaff sieve 44 changes. By the swinging of the second chaff sieve 44, the objects to be sorted on the second chaff sieve 44 are sieved and sorted while being transferred backward, and objects to be sorted that are smaller than the interval between the chaff flips 48 drop through the chaff flips 48. The objects to be sorted remaining on the second chaff sieve 44 are blown backward by the sorting wind from the winnower 46.

[0045] The threshing device 7 is provided with a first grain recovery section 51 and a second grain recovery section 52 below the sorting section 22.

[0046] The sorting objects that leak from the grain sieve 45 are winnowed by the sorting wind from the winnower 46. This winnowing blows the sorting objects with a smaller specific gravity than the grains backward, and the sorting objects mainly containing grains are collected as No. 1 items in the No. 1 item recovery section 51. The No. 1 item recovery section 51 is equipped with a screw auger 53 that rotates about a rotation axis that extends in the left-right direction, and the No. 1 items recovered in the No. 1 item recovery section 51 are transported to the transport device 15 by the screw auger 53.

[0047] The sorting objects leaking out from the second chaff sieve 44 are collected as No. 2 objects in the No. 2 object recovery section 52. The No. 2 objects collected in the No. 2 object recovery section 52 mainly contain grains that were not collected as No. 1 objects, and are reduced by the reduction device 54 to the sorting section 22 from a reduction port 55 provided outside the receiving net 25 and above the first chaff sieve 43. As a result, the No. 2 objects are re-sorted in the sorting section 22 into sorting objects (mainly grains) that are collected as No. 1 objects, and sorting objects (mainly impurities) that are not collected as No. 1 objects.

[0048] <Transportation equipment> Fig. 4 is a front view of the threshing device 7 and the conveying device 15, together with a cross-section of the grain tank 8. Fig. 5 is a cross-sectional view of the conveying device 15 cut along a cut surface along the front-rear direction, as viewed from the right.

[0049] The conveying device 15 is provided between the threshing device 7 and the grain tank 8. The conveying device 15 includes a vertical conveying section 61 that conveys the first grains conveyed from the first grain recovery section 51 of the threshing device 7 upward, and a horizontal conveying section 62 that conveys the first grains sent by the vertical conveying section 61 to the right and deposits them into the grain tank 8.

[0050] The vertical conveying section 61 is equipped with a vertical conveying case 63 extending in the up-down direction. A driving sprocket 64 is provided at the lower end of the vertical conveying case 63 so as to be rotatable about a rotation axis extending in the left-right direction, and a driven sprocket 65 is provided at the upper end of the vertical conveying case 63 so as to be rotatable about a rotation axis extending in the left-right direction. An endless chain 66 is wound around the driving sprocket 64 and the driven sprocket 65, and a plurality of buckets 67 are attached to the chain 66 at regular intervals.

[0051] The horizontal conveying section 62 is provided with a horizontal conveying case 71 connected to the upper end of the vertical conveying case 63. The horizontal conveying case 71 extends in the left-right direction and is inserted into a left side wall 72 of the grain tank 8, with its left end disposed within the grain tank 8. The right end of the horizontal conveying case 71 communicates with the interior of the vertical conveying case 63 via a communication port 73. The lower surface of the left end of the horizontal conveying case 71 is open downwardly as a discharge port 74. A screw auger 75 that rotates about a rotation axis extending in the left-right direction is provided within the horizontal conveying case 71.

[0052] The first grains transported by the screw auger 53 from the first grain recovery section 51 of the threshing device 7 are carried into the vertical transport case 63. The driving force input to the drive sprocket 64 rotates the drive sprocket 64, and the chain 66 moves in a circular motion with the rotation, and the driven sprocket 65 rotates. The first grains are loaded into the bucket 67 which rises due to the circular motion of the chain 66, and when the bucket 67 with the first grains loaded therein reverses its moving direction around the driven sprocket 65, the first grains loaded in the bucket 67 are discharged from the bucket 67 through the communication port 73 into the horizontal transport case 71. The first grains received by the horizontal transport case 71 are transported through the horizontal transport case 71 toward the discharge port 74 by the rotation of the screw auger 75, and are discharged from the discharge port 74 into the grain tank 8.

[0053] <Flow sensor No. 1> A first flow rate sensor 81 for detecting the flow rate of the first object discharged from the vertical conveying section 61 to the horizontal conveying section 62 is attached to the horizontal conveying case 71 of the conveying device 15. The first flow rate sensor 81 is equipped with an actuator 82. The actuator 82 is provided so as to be swingable about a rotation axis extending in the left-right direction, and is disposed so that its tip portion faces the communication port 73.

[0054] When the first object loaded in the bucket 67 of the vertical conveyor 61 is released into the horizontal conveyor case 71 through the communication port 73, the released object collides with the actuator 82, causing the actuator 82 to swing. The first flow rate sensor 81 has a built-in potentiometer and outputs a detection signal (voltage) according to the swing angle of the actuator 82.

[0055] <Flow sensor No. 2> FIG. 6 is a cross-sectional view of the threshing device 7 taken along a cross section along the left-right direction.

[0056] A No. 2 flow rate sensor 83 is attached to the inner surface of the left side plate 31 of the threshing device 7, for detecting the flow rate of the No. 2 grain being returned from the No. 2 grain recovery section 52 to the sorting section 22 of the threshing device 7. The No. 2 flow rate sensor 83 is equipped with an actuator 84. The actuator 84 is provided so as to be swingable about a rotation axis extending in the front-rear direction, and is positioned so that its tip faces the return port 55.

[0057] When the second product to be returned from the second product recovery section 52 to the sorting section 22 is released through the return port 55 by the return device 54, the released second product collides with the actuator 84, causing the actuator 84 to swing. The second flow rate sensor 83 has a built-in potentiometer and outputs a detection signal (voltage) according to the swing angle of the actuator 84.

[0058] <Main parts of the combine harvester's electrical configuration> FIG. 7 is a block diagram showing a main part of the electrical configuration of the combine harvester 1. As shown in FIG.

[0059] The combine harvester 1 is equipped with a control device 91 for controlling each part of the combine harvester 1. The control device 91 includes a microcomputer (microcontroller), and the microcomputer includes, for example, a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a dynamic random access memory (DRAM).

[0060] The control device 91 receives detection signals from the first flow rate sensor 81 and the second flow rate sensor 83. In addition, the control device 91 receives information necessary for controlling each part, such as the vehicle speed of the combine harvester 1.

[0061] A map or formula showing the relationship between the swing angle of the actuator 82 of the No. 1 flow sensor 81 and the flow rate of the No. 1 object discharged into the horizontal conveying case 71 is stored in a non-volatile memory built into the control device 91, and the control device 91 estimates, based on the map or formula, the flow rate of the No. 1 object corresponding to the swing angle represented by the detection signal of the No. 1 flow sensor 81 as the No. 1 recovery flow rate. Also, a map or formula showing the relationship between the swing angle of the actuator 84 of the No. 2 flow sensor 83 and the flow rate of the No. 2 object returned to the sorting section 22 is stored in a non-volatile memory built into the control device 91, and the control device 91 estimates, based on the map or formula, the flow rate of the No. 2 object corresponding to the swing angle represented by the detection signal of the No. 2 flow sensor 83 as the No. 2 return flow rate.

[0062] The control device 91 has a function of controlling the threshing device 7. The control of the threshing device 7 will be described later.

[0063] The control device 91 also has a function of controlling the engine 4 and the transmission 5 to change the driving force transmitted to the crawler traveling device 2 and control the vehicle speed of the combine 1 caused by the crawler traveling device 2.

[0064] In the cabin 6, a touch panel 92 is disposed at a position where a user seated in the driver's seat 12 can operate it. The touch panel 92 is configured, for example, by overlapping a pressure-sensitive or capacitive transparent film switch on a display such as a liquid crystal display. Images of various information and operation buttons are displayed on the touch panel. When the user touches an operation button, an instruction corresponding to the type of the operation button that was touched is received by the touch panel 92. When the instruction is received by the touch panel 92, a signal corresponding to the content of the instruction is input from the touch panel 92 to the control device 91. In addition, the user can input a numerical value by a touch operation. When a numerical value is input, a signal corresponding to the input numerical value is input from the touch panel 92 to the control device 91.

[0065] <Target value setting process> FIG. 8 is a flowchart showing the flow of the target value setting process.

[0066] In order to control the threshing device 7, the control device 91 executes a target value setting process.

[0067] In the target value setting process, it is determined whether or not a crop to be harvested by the combine harvester 1 has been specified (step S11). Before the combine harvester 1 starts harvesting a crop, a user touches the touch panel 92 to specify the crop to be harvested. Crops to be harvested include rice, barley, and wheat. If the crop to be harvested is not specified and harvesting of the crop is started, the control device 91 may automatically specify a predetermined crop as the crop to be harvested.

[0068] When the crop to be harvested is designated (YES in step S11), a target value for the return flow rate of the second crop corresponding to the designated crop is set (step S12).

[0069] Thereafter, it is determined whether or not an instruction to change the target value has been input (step S13). The instruction to change the target value is input from the touch panel 92 to the control device 91 together with a signal corresponding to the changed target value or the amount of change in the target value by the user touching the touch panel 92.

[0070] When an instruction to change the target value is input (YES in step S13), the previously set target value is changed according to the instruction (step S14), and the target value is reset. Then, it is determined whether the opening degree of the second chaff sieve 44 (hereinafter referred to as the "R chaff opening degree") is a reference value (step S15).

[0071] If a predetermined time has elapsed since the target value was set and no instruction to change the target value is input (NO in step S13), the target value is not changed and it is determined whether the R chaff opening is at the reference value (step S15).

[0072] If the R chaff opening is the reference value (YES in step S15), the target value setting process is ended.

[0073] The target value of the second return flow rate is set for each crop with the R chaff opening set to a reference value. Therefore, if the R chaff opening deviates from the reference value, the target value of the second return flow rate cannot be set appropriately. Therefore, for example, if the R chaff opening is changed according to the vehicle speed and the R chaff opening deviates from the reference value (NO in step S15), the previously set target value is changed according to the R chaff opening (S16) to reset the target value. Specifically, if the R chaff opening is smaller than the reference value, the target value is lowered according to the R chaff opening. On the other hand, if the R chaff opening is larger than the reference value, the target value is raised according to the R chaff opening. After the target value is changed, the target value setting process is terminated.

[0074] <No. 2 return flow control> FIG. 9 is a flowchart showing the flow of the second return flow rate control.

[0075] When the combine harvester 1 starts harvesting the crops, the control device 91 starts the second return flow rate control.

[0076] In the second return flow rate control, the second return flow rate is estimated based on the detection signal of the second flow rate sensor 83 (step S21).

[0077] It should be noted that the "second return flow rate" used in the description of Figs. 9 and 10 means the second return flow rate estimated in step S21.

[0078] Thereafter, it is determined whether the second return flow rate matches the target value set in the target value setting process (step S22). The determination of whether the second return flow rate matches the target value may be a determination of whether the second return flow rate is included in a predetermined range including the target value.

[0079] If the second return flow rate matches the target value (YES in step S22), it is determined whether or not the harvesting of the crop by the combine 1 is completed (step S23). If the harvesting is not completed (NO in step S23), the process returns to step S21 and the second return flow rate is estimated again.

[0080] If the second return flow rate does not match the target value (NO in step S22), it is determined whether the second return flow rate is a value smaller than the target value (step S24).

[0081] If the No. 2 return flow rate is smaller than the target value (YES in step S24), the opening of the first chaff sieve 43 (hereinafter referred to as the "F chaff opening") is reduced, and the volume of sorting air by the winnower 46 is reduced (step S25). The reduction in the F chaff opening and the reduction in the volume of sorting air may each be a fixed amount, or may be an amount according to the deviation of the No. 2 return flow rate from the target value.

[0082] Thereafter, it is determined whether or not the harvesting of the crops by the combine 1 has been completed (step S23), and if the harvesting has not been completed (NO in step S23), the second return flow rate is estimated again (step S21).

[0083] If the No. 2 return flow rate is not smaller than the target value (NO in step S24), that is, if the No. 2 return flow rate is larger than the target value, the F chaff opening is increased and the volume of sorting air by the winnower 46 is increased (step S26). The increase in the F chaff opening and the increase in the volume of sorting air may each be a fixed amount, or may be an amount according to the deviation of the No. 2 return flow rate from the target value.

[0084] Thereafter, it is determined whether or not the harvesting of the crops by the combine 1 has been completed (step S23), and if the harvesting has not been completed (NO in step S23), the second return flow rate is estimated again (step S21).

[0085] The processes of steps S21 to S26 are repeated until the harvesting of the crops by the combine harvester 1 is completed, and when the harvesting is completed (YES in step S23), the second return flow rate control is terminated.

[0086] <Vehicle speed control> FIG. 10 is a flowchart showing the flow of vehicle speed control.

[0087] While the combine harvester 1 is harvesting crops, the control device 91 executes vehicle speed control at a predetermined cycle.

[0088] In the vehicle speed control, it is determined whether the second return flow rate is greater than the target value (step S31).

[0089] If the No. 2 return flow rate is greater than the target value (YES in step S31), it is determined whether the F chaff opening degree is at a maximum (step S32).

[0090] When the second return flow rate is greater than the target value and the F chaff opening is at its maximum (YES in step S32), in other words, when the second return flow rate is greater than the target value even though the F chaff opening is at its maximum, the vehicle speed is decelerated (step S33) and the vehicle speed control is terminated. The amount of deceleration of the vehicle speed may be a fixed amount or may be an amount according to the amount of deviation of the second return flow rate from the target value.

[0091] If the second return flow rate is not greater than the target value (NO in step S31), or if the F chaff opening is not at its maximum (NO in step S32), the vehicle speed is not reduced and the vehicle speed control is ended.

[0092] <Action and effect> As described above, the second flow rate sensor 83 detects a value correlated with the return flow rate of the second grain. Meanwhile, the control device 91 sets a target value for the return flow rate of the second grain. Then, the control device 91 controls the first chaff sieve 43 and the winnower 46 so that the second return flow rate estimated from the detection value of the second flow rate sensor 83 coincides with the target value, and changes the F chaff opening and the wind volume of the sorting air by the winnower 46. This adjusts the return flow rate of the second grain to the target value, so that the amount of the sorting objects stored in the threshing device 7 is stabilized. As a result, the sorting objects can be sorted at a processing speed according to the amount of crops supplied to the threshing device 7, while suppressing deterioration of sorting performance due to field conditions.

[0093] The target value for the return flow rate of the second crop is set for each crop. This allows the appropriate target value to be set for each crop.

[0094] In addition, the user can change the target value of the return flow rate of the No. 2 product by touching the touch panel 92. By making such a change, the user can adjust the sorting process speed and sorting performance (the ratio of impurities contained in the No. 1 product).

[0095] Since the amount of second-class rice sorted varies depending on the R chaff opening, the target value is changed according to the R chaff opening. This makes it possible to keep the amount of rice to be sorted stored in the threshing device 7 stable.

[0096] When the F chaff opening is at its maximum, and the No. 2 return flow rate estimated from the detection value of the No. 2 flow rate sensor 83 is greater than the target value, the vehicle speed of the combine harvester 1 is decelerated. This reduces the amount of crop supplied to the threshing device 7 and reduces the No. 2 return flow rate, thereby suppressing an increase in sorting loss.

[0097] <Modification> Although one embodiment of the present invention has been described above, the present invention can be embodied in other forms.

[0098] For example, when the No. 2 return flow rate estimated from the detection value of the No. 2 flow rate sensor 83 is smaller than a standard, the volume of the sorting air from the winnower 46 may be changed according to the No. 1 return flow rate estimated from the detection value of the No. 1 flow rate sensor 81 so that the return flow rate of the No. 2 material is increased.

[0099] In addition, various design modifications can be made to the above-described configuration within the scope of the claims. [Explanation of symbols]

[0100] 1: Combine 2: Crawler driving device (driving device) 3: Aircraft frame (aircraft) 6: Cabin (aircraft) 7: Threshing device (machine) 8: Grain tank (aircraft) 21: Threshing Department 22: Sorting Department 43: 1st Chaff Seeb (Chaff Seeb) 44: 2nd Chaff Seeb (Chaff Seeb) 46: Karakinou 81: No. 1 flow sensor 83: No. 2 flow sensor 91: Control device 92: Touch panel (input device)

Claims

1. a threshing device which causes a sorting object, including grains and impurities obtained by threshing a crop in a threshing section, to flow into a sorting section, which sorts grains from the sorting object in the sorting section, recovers the sorted No. 1 grains, and which sorts grains from the sorting object excluding the No. 1 grains in the sorting section, and returns the sorted No. 2 grains to the sorting section; a second flow rate sensor for detecting a value correlated with the return flow rate of the second product; a control device; The sorting unit includes a second chaff sieve whose sorting amount of the second object changes depending on its opening degree, The control device includes: A target value of the return flow rate is set, and the sorting unit is controlled so that the return flow rate obtained from the detection value of the second flow rate sensor coincides with the target value; A combine that changes the target value depending on the opening degree of the second chaff sieve.

2. The sorting unit includes a first chaff sieve whose sorting amount of the first object changes depending on its opening degree, The combine harvester of claim 1, wherein the control device reduces the opening degree of the first chaff sieve when the return flow rate obtained from the detection value of the second flow sensor is smaller than the target value, and increases the opening degree of the first chaff sieve when the return flow rate obtained from the detection value of the second flow sensor is larger than the target value.

3. The sorting unit includes a winnower that generates a sorting wind for wind sorting the objects to be sorted, The combine harvester of claim 2, wherein the control device reduces the volume of the sorting air by the winnower when the return flow rate obtained from the detection value of the second flow sensor is smaller than the target value, and increases the volume of the sorting air by the winnower when the return flow rate obtained from the detection value of the second flow sensor is greater than the target value.

4. The combine harvester according to claim 1 , wherein the control device sets the target value for each crop.

5. An input device for inputting an instruction to change the target value, The combine harvester according to claim 1 , wherein the control device changes the target value in response to an instruction input from the input device.

6. Further includes a pair of left and right traveling devices that support a machine body including the threshing device and are driven by the power of a power source; The combine harvester of claim 2, wherein the control device reduces the vehicle speed of the traveling device when the opening degree of the first chaff sieve is maximum and the return flow rate obtained from the detection value of the second flow sensor is greater than the target value by a predetermined amount or more.

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