Combine harvester and control method thereof

Abstract

The invention provides a combine harvester, which can prevent a cutting part from contacting with the ground or being inserted into the ground in a structure for controlling the height of the cutting part, and can prevent cutting defects such as residual cutting. A combine harvester is provided with: a harvesting unit provided so as to be capable of rising and falling relative to a traveling machine body; a cutting height detection device for detecting a cutting height, which is the height of the cutting unit to the ground; a relative-body height detection device for detecting the relative-body height, which is the height of the cutting unit relative to the traveling body; and a control device for controlling the height of the cutting unit. The control device performs: cutting height control for controlling the height of the cutting unit so that the cutting height detected by the cutting height detection device reaches a predetermined target value; and a rising and falling range limiting control for limiting the rising and falling range of the reaping unit within a predetermined rising and falling range with respect to a reaping reference height, which is a reference value for the height of the machine body. The rising and falling range limiting control is invalidated during a period from the start of the control until the travel distance of the traveling machine body reaches a predetermined distance.

Description

Technical Field

[0001] The present invention relates to a combine harvester having a harvesting part whose height can be adjusted and a control method of the combine harvester. Background Art

[0002] In general, a combine harvester has a harvesting section on the front side of a traveling machine body, and a threshing section on the traveling machine body, and performs harvesting of ear stalks by the harvesting section and threshing by the threshing section while traveling. In the past, a combine harvester had a structure in which a harvesting height detection device was provided in order to set the harvesting section to be able to be raised and lowered relative to the traveling machine body and control the height of the harvesting section relative to the ground, i.e., the harvesting height (height to the ground) (see, for example, Patent Document 1). With this structure, the action of a lifting device such as a hydraulic cylinder that lifts and lowers the harvesting section is controlled based on a detection signal of the harvesting height detection device, thereby automatically controlling the harvesting height.

[0003] Patent Document 1 describes the following control content regarding the height control of the cutting section: at the start of the operation, the machine body is more likely to tilt in the front-to-back direction than during the normal cutting operation, so the cutting height detection device switches to the cutting height detection state at the start of the operation and stops the descending action of the cutting section for a predetermined time thereafter. It is conceivable that according to this height control of the cutting section, the descending action of the cutting section is restricted at the start of the operation, so that even when the machine body is tilted in the front-to-back direction, the cutting section can be prevented from contacting or digging into the ground.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Utility Model Publication No. 61-7533 Summary of the invention

[0007] According to the height control of the cutting section disclosed in Patent Document 1, the descending action of the cutting section is stopped during a predetermined time. Therefore, even if the cutting section can be prevented from contacting the ground, it is possible that the target cutting height is not reached during the cutting operation, resulting in cutting residues and other poor cutting conditions.

[0008] The present invention is completed in view of the above-mentioned problems, and its purpose is to provide a combine harvester and a control method for the combine harvester as follows: in a structure for controlling the height of the harvesting part, the harvesting part can be prevented from contacting or inserting into the ground, and poor harvesting conditions such as harvesting residues can be suppressed.

[0009] The combine harvester according to the present invention comprises: a harvesting section arranged to be able to be raised and lowered relative to a traveling machine body; a harvesting height detection device for detecting the height of the harvesting section relative to the ground, i.e., the harvesting height; a machine body height detection device for detecting the height of the harvesting section relative to the traveling machine body, i.e., the machine body height; and a control device for controlling the height of the harvesting section based on detection signals of the harvesting height detection device and the machine body height detection device, wherein the control device performs the following control: harvesting height control in which the height of the harvesting section is controlled so that the harvesting height detected by the harvesting height detection device reaches a predetermined target value; and lifting range restriction control in which the lifting range of the harvesting section is restricted within a predetermined range of a rising amount and a falling amount relative to a cutting reference height which is a reference value of the machine body height detected by the machine body height detection device, and the lifting range restriction control is invalidated from the start of control until the travel distance of the traveling machine body reaches a predetermined distance or until a predetermined time has passed.

[0010] The combine harvester according to the present invention comprises: a harvesting section arranged to be able to be raised and lowered relative to a traveling machine body; a harvesting height detection device for detecting the height of the harvesting section relative to the ground, i.e., the harvesting height; a machine body height detection device for detecting the height of the harvesting section relative to the traveling machine body, i.e., the machine body height; and a control device for controlling the height of the harvesting section based on detection signals of the harvesting height detection device and the machine body height detection device, wherein the control device performs the following control: harvesting height control in which the height of the harvesting section is controlled so that the harvesting height detected by the harvesting height detection device reaches a predetermined target value; and lifting range restriction control in which the lifting range of the harvesting section is restricted within a predetermined range of a rising amount and a falling amount relative to a cutting reference height which is a reference value of the machine body height detected by the machine body height detection device, and the lifting range restriction control is invalidated during a period from when the control is started until the vehicle speed of the traveling machine body reaches a predetermined speed.

[0011] In the combine harvester according to another aspect of the present invention, the control device calculates the harvesting reference height as an average value of the machine body height stored at predetermined time intervals and updates the calculation at predetermined time intervals.

[0012] Regarding the control method of the combine harvester involved in the present invention, the height of the cutting part above the ground, i.e., the cutting height, and the height of the cutting part relative to the traveling body, i.e., the relative body height, are detected, and the height of the cutting part is controlled based on the detected cutting height and relative body height, wherein the following controls are performed: cutting height control, in which the height of the cutting part is controlled in such a way that the detected cutting height reaches a specified target value; and lifting range limitation control, in which the lifting range of the cutting part is limited within a specified range of rising and falling amounts relative to a reference value for the relative body height, i.e., the cutting reference height, and the lifting range limitation control is rendered invalid from the start of control until the traveling distance of the traveling body reaches a specified distance, or until a specified time has passed.

[0013] Regarding the control method of the combine harvester involved in the present invention, the height of the cutting section above the ground, i.e., the cutting height, and the height of the cutting section relative to a traveling machine body, i.e., the machine body height, are detected, and the height of the cutting section is controlled based on the detected cutting height and machine body height, wherein the following controls are performed: cutting height control, in which the height of the cutting section is controlled in such a way that the detected cutting height reaches a specified target value; and lifting range limitation control, in which the lifting range of the cutting section is limited within a specified range of rising and falling amounts relative to a reference value for the machine body height, i.e., the cutting reference height, and the lifting range limitation control is rendered invalid during the period from the start of control until the vehicle speed of the traveling machine body reaches a specified speed.

[0014] In another control method of a combine harvester according to the present invention, the harvesting reference height is calculated as an average value of machine body heights stored at predetermined time intervals and updated at predetermined time intervals.

[0015] Effects of the Invention

[0016] According to the present invention, it is possible to suppress the cutting portion from coming into contact with or digging into the ground, and to suppress the cutting residue from remaining. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a left side view of the combine harvester which concerns on one Embodiment of this invention.

[0018] Figure 2 It is a right side view of the combine harvester which concerns on one Embodiment of this invention.

[0019] Figure 3 It is a top view which shows the structure of the harvesting part of the combine harvester which concerns on one Embodiment of this invention.

[0020] Figure 4 It is a left side view showing the structure of the grain separating part and the cutting height detection device involved in one embodiment of the present invention.

[0021] Figure 5 This is a left front perspective view showing a cutting height detection device and a supporting structure thereof according to an embodiment of the present invention.

[0022] Figure 6 This is a left side view showing a cutting height detection device and a supporting structure thereof according to an embodiment of the present invention.

[0023] Figure 7 This is a right side view showing a cutting height detection device and a supporting structure thereof according to an embodiment of the present invention.

[0024] Figure 8 It is a top view of the cutting height detection device according to one embodiment of the present invention.

[0025] Fig. 9 It is a front perspective view showing a sensor unit according to an embodiment of the present invention.

[0026] Fig.10 This is a block diagram showing a control structure of a combine harvester according to one embodiment of the present invention.

[0027] Fig.11 This is a diagram showing an example of an operation unit for harvesting work included in the combine harvester according to the embodiment of the present invention.

[0028] Fig.12 This is a diagram showing an example of the operating state of the automatic cutting height switch and the mode display unit according to one embodiment of the present invention.

[0029] Fig.13 It is an explanatory diagram regarding the lifting range limitation control according to one embodiment of the present invention.

[0030] Fig.14 It is an explanatory diagram regarding a first control mode of the lifting and lowering control of the harvesting unit according to one embodiment of the present invention.

[0031] Fig.15 It is an explanatory diagram regarding calculation and updating of a cutting reference height according to one embodiment of the present invention.

[0032] Fig.16 It is an explanatory diagram regarding a second control mode of the lifting and lowering control of the harvesting unit according to the embodiment of the present invention.

[0033] Fig.17It is an explanatory diagram regarding a third control mode of the lifting and lowering control of the harvesting unit according to the embodiment of the present invention.

[0034] Fig.18 This is a flowchart showing an example of processing related to the cutting reference height by the control device according to the embodiment of the present invention.

[0035] Fig.19 This is an explanatory diagram regarding the problem of raising and lowering control of the harvesting unit.

[0036] Fig. 20 This is an explanatory diagram regarding the problem of raising and lowering control of the harvesting unit.

[0037] Description of Reference Numerals

[0038] 1…Combine harvester; 4…Traveling body; 5…Cutting section; 40…Cutting height detection device; 43…Cutting height sensor; 200…Control device; 201…Vehicle speed sensor; 202…Cutting height adjustment dial; 203…Body height sensor (Body height detection device). DETAILED DESCRIPTION

[0039] The present invention is formed as follows: a cutting part having an adjustable height is provided, the height of the cutting part is controlled based on a detected value of a cutting height as the height of the cutting part, wherein the control content is divided according to the control in the initial stage after the control starts and the control thereafter, thereby suppressing the cutting part from contacting with or digging into the ground, and suppressing the cutting defect such as cutting residue. Embodiments of the present invention are described below.

[0040] [Overall structure of a combine harvester]

[0041] use Figure 1 and Figure 2 The overall structure of the combine harvester 1 according to the present embodiment will be described. Figure 1 The left side in FIG. 1 is a diagram showing a left side in FIG. 1 and a right side in FIG. 1 , and the left side and the right side are respectively set as the left side and the right side of the combine harvester 1.

[0042] like Figure 1 and Figure 2 As shown, the combine harvester 1 according to the present embodiment includes: a traveling section 2 which is a crawler-type traveling device having a pair of left and right crawler sections 3, 3; and a traveling machine body 4 which is supported by the traveling section 2. The traveling machine body 4 includes a frame-shaped structural part of the vehicle body of the combine harvester 1. The combine harvester 1 includes an engine 11 as a driving source mounted on the traveling machine body 4.

[0043] A harvesting section 5 for harvesting and taking in the stalks of rice, wheat, etc. in the field is provided at the front of the traveling body 4. A threshing section 6 for threshing the stalks harvested by the harvesting section 5 and a grain tank 7 for storing the grains taken out from the threshing section 6 are provided in a horizontal arrangement on the traveling body 4. The threshing section 6 is arranged on the left side of the machine body, and the grain tank 7 is arranged on the right side of the machine body. The combine harvester 1 harvests the stalks by the harvesting section 5 and thres the stalks by the threshing section 6 while traveling by the traveling section 2.

[0044] Each crawler section 3 constituting the traveling section 2 includes: a track frame 3a extending in the front-rear direction below the traveling machine body 4; various rotating bodies such as a driving sprocket 3b supported by the track frame 3a; and a crawler 3c wound around the rotating bodies. The crawler section is driven by receiving power transmitted from the engine 11 at the driving sprocket 3b.

[0045] The harvesting section 5 is driven by the driving force from the engine 11 to harvest the stalks and convey the harvested stalks to the threshing section 6 or the like. The harvesting section 5 is provided on the front side of the traveling body 4 over substantially the entire body width of the combine harvester 1. The harvesting section 5 is provided so as to be able to be raised and lowered relative to the traveling body 4. Figure 2 Shows relative to Figure 1 The state shown in FIG. 1 is a state in which the cutting section 5 is lowered.

[0046] The threshing section 6 includes: a threshing cylinder 6a, which has a rotation axis direction in the front-rear direction; and an ear stalk supply device, which is provided on the left side of the threshing cylinder 6a. The ear stalk supply device clamps the root of the ear stalk cut by the cutting section 5 and conveys the ear stalk to the rear in a horizontal position such that the ear tip is located on the side of the threshing cylinder 6a. The ear stalk supply device is configured to include: a feed chain 6b, which is wound around a plurality of sprockets, which have a rotation axis direction in the left-right direction; and an ear stalk supply clamping body 6c, which cooperates with the above components to clamp the root of the ear stalk.

[0047] A screening section 8 for screening the processed material threshed by the threshing section 6 is provided below the threshing section 6 on the traveling machine body 4. The screening section 8 includes a swing screening device 8a, a wind screening device, and a grain conveying device. The screening section 8 performs swing screening on the processed material dropped from the threshing section 6 by the swing screening device 8a, and performs wind screening on the processed material after swing screening by the wind screening device. The screening section 8 uses the grain conveying device to convey the grains in the processed material after wind screening toward the grain box 7 and to the right, and uses the wind screening device to blow away straw scraps, dust, etc. to the rear and discharge them to the outside of the machine body. The grains conveyed to the grain box 7 by the grain conveying device are stored in the grain box 7.

[0048] The discharge auger 9 as a grain discharge device for discharging the grains in the grain box 7 to the outside is rotatably provided at the right rear end portion of the traveling body 4. The discharge auger 9 has a discharge port 9a at the terminal end, and the grains stored in the grain box 7 are discharged from the discharge port 9a. The grains discharged from the discharge port 9a are put into a cargo box of a truck, a container, etc.

[0049] On the traveling machine body 4, a discharge straw processing unit 10 for processing discharge straw after threshing by the threshing unit 6 is arranged at the rear of the threshing unit 6. The discharge straw processing unit 10 includes a discharge straw conveying device 10a and a discharge straw cutting device 10b. The discharge straw conveying device 10a conveys the ear stalk (discharge straw) threshed by the threshing unit 6 to the rear and discharges it to the outside of the machine body, or conveys it to the discharge straw cutting device 10b. The discharge straw cutting device 10b cuts the discharge straw conveyed by the discharge straw conveying device 10a and discharges it to the outside of the machine body.

[0050] On the traveling machine body 4, a driving section 14 covered by a cab 13 is provided on the right side of the harvesting section 5 and in front of the grain tank 7. A steering wheel section 15 as a steering operation section is provided in front of the driving section 14, a driver's seat 16 is provided behind the steering wheel section 15, and a side operating section 12 (see FIG. 1 ) arranged on a side column 19 and including various operating parts including a main gear lever 17, a dial, a switch, and other operating section groups 300 is provided on the side of the driver's seat 16. Fig.11 ).

[0051] A prime mover unit including an engine 11 is provided below the cab 14. The engine 11 is, for example, a diesel engine. The power of the engine 11 is transmitted to various devices provided in various parts of the combine harvester 1 via a transmission device and the like.

[0052] use Figures 1 to 3 The harvesting section 5 is described. The harvesting section 5 is configured to include a harvesting support frame 20 as a harvesting frame, a grain dividing plate 21, a lifting device 22, a raking device 23, a cutting knife device 24, an ear stalk conveying device 25, etc. on the harvesting support frame 20. Each device of the harvesting section 5 is operated by power transmitted from the engine 11.

[0053] The grain-dividing plate 21 is an example of a grain-dividing body constituting the grain-dividing part 50 of the harvesting part 5, and is provided at the front part of the harvesting part 5. The grain-dividing plate 21 has a tapered shape at the front end, and divides the stalks planted in the field. The lifting device 22 is provided at the rear side of the grain-dividing plate 21, and operates a plurality of rake teeth 22a connected by a chain to lift up the fallen stalks.

[0054] The raking device 23 is provided at the rear side of the lifting device 22 and is configured to rake the ear stalks including a chain-driven conveying mechanism 23a, a rotary baler 23b, etc. Figure 3 In FIG. 1 , only the component part provided at the left end part of the raking device 23 is shown, and the illustration of other components is omitted.

[0055] The cutting knife device 24 is a clipper-type device that cuts the root of the raised ear stalk. The ear stalk conveying device 25 is a device that conveys the cut ear stalks, so that the ear stalks cut from multiple ridges are combined and conveyed backward and upward, and are handed over to the starting end of the feed chain 6b of the threshing section 6 in a horizontal position.

[0056] like Figure 1 As shown, the harvesting support frame 20 is supported by a support frame 26 configured to be low in front and high in the back on the front side of the traveling body 4. The support frame 26 is provided at the substantially central part of the body in the left-right direction, and the harvesting support frame 20 is provided on the front side of the support frame 26.

[0057] like Figure 3 As shown, the harvesting support frame 20 includes a transverse frame 31 extending in the left-right direction of the machine body and a plurality of crop separation frames 32 and 34 extending forward from the transverse frame 31. The harvesting support frame 20 is supported by the support frame 26 at the transverse frame 31.

[0058] The transverse frame 31 is a straight frame portion formed of a square tube-shaped member. The straw-dividing frames 32 and 34 are frame portions formed of a circular tube-shaped member, have a predetermined curved shape or a bent shape, and extend in the front-to-back direction when viewed from above. The straw-dividing frames 32 and 34 are supported in a cantilevered manner by fixing the rear end portion or the rear portion to the transverse frame 31.

[0059] A plurality of straw dividing frames 32, 34 are arranged at predetermined intervals in the left-right direction. The straw dividing frames 32, 34 are provided with one more number than the number of ridges cut by the combine harvester 1. The combine harvester 1 involved in the present embodiment is a 6-ridge cutting type, and is provided with 7 straw dividing frames 32, 34. Among the 7 straw dividing frames 32, 34, the straw dividing frames 34 that are the second and sixth from the left, respectively, have shapes different from the other multiple (5) straw dividing frames 32.

[0060] A lifting device 22 is arranged between the adjacent straw-dividing frames 32, 34 in the left-right direction, and a total of 6 lifting devices 22 are provided. The lower portion of the lifting device 22 is connected and supported to the front portion of each straw-dividing frame 32, 34 by means of a supporting strut not shown in the figure. In addition, a straw-dividing board 21 is installed at the front portion of each straw-dividing frame 32, 34. In addition, as a plurality of straw-dividing boards 21, two types of straw-dividing boards 21, larger and smaller, are arranged in a prescribed configuration. In the present embodiment, four larger straw-dividing boards 21 and three smaller straw-dividing boards 21 are alternately arranged in the left-right direction.

[0061] The cutting section 5 having the above structure is provided with a cutting lifting cylinder 18 (see Figure 1 ) is mounted on the traveling body 4 in a manner that allows rotation around a predetermined rotation axis. That is, the harvesting section 5 is provided so as to be able to be raised and lowered relative to the traveling body 4 by a rotational movement based on the telescopic movement of the harvesting lift cylinder 18. The harvesting lift cylinder 18 is a hydraulic cylinder and is provided between the traveling body 4 and the support frame 26. The rear end portion of the support frame 26 is supported on the traveling body 4 in a manner that allows rotation around an axis in the left-right direction as a rotation fulcrum for the lifting and lowering movement of the harvesting section 5 based on the harvesting lift cylinder 18.

[0062] As described above, the combine harvester 1 is provided so that the harvesting section 5 can be raised and lowered relative to the traveling body 4. Furthermore, the combine harvester 1 includes a harvesting height detection device 40 and a control device 200 (see FIG. 2 ) for controlling the height of the harvesting section 5 relative to the ground 30, that is, the harvesting height (height above the ground). Fig.10 With this configuration, the control device 200 controls the operation of the harvesting lift cylinder 18 for raising and lowering the harvesting section 5 based on the detection signal of the harvesting height detection device 40, thereby automatically controlling the harvesting height.

[0063] The operation of the solenoid valve as the control valve is controlled to control the operation of the harvesting lift cylinder 18. The control device 200 controls the operation of the control valve of the harvesting lift cylinder 18 based on the detection signal of the harvesting height detection device 40 to control the harvesting height.

[0064] Regarding the automatic control of the cutting height, the operation of the control valve of the cutting lifting cylinder 18 is controlled so as to maintain the cutting height of the cutting section 5 at a set value based on the detection signal of the cutting height detection device 40, thereby automatically controlling the lifting and lowering of the cutting section 5. Regarding the automatic control of the cutting height, the control device 200 controls the height of the cutting section 5 so that the cutting height detected by the cutting height detection device 40 reaches a preset target value (hereinafter referred to as "cutting height target value").

[0065] That is, when the detected cutting height is lower than the cutting height target value, the control device 200 raises the cutting section 5, and when the detected cutting height exceeds the cutting height target value, the control device 200 lowers the cutting section 5, thereby performing lifting and lowering control of the cutting section 5 in such a manner that the height of the cutting section 5 is maintained at a height corresponding to the cutting height target value.

[0066] In the automatic control of the cutting height, the cutting height target value may be set to a value within a predetermined range (a value having a range). In this case, when the detected cutting height is lower than the lower limit of the cutting height target value, the control device 200 raises the cutting section 5, and when the detected cutting height exceeds the upper limit of the cutting height target value, the control device 200 lowers the cutting section 5, thereby performing the lifting and lowering control of the cutting section 5 in such a manner that the height of the cutting section 5 is maintained within the range of the height corresponding to the cutting height target value.

[0067] The driving unit 14 is provided with an operating unit for adjusting the cutting height. For example, in the automatic control of the cutting height, the control of the cutting height adjustment based on the operation of the operating unit for adjusting the cutting height is given priority. As the operating unit for adjusting the cutting height, a cutting lifting rod 35 (see FIG. 1 ) for lifting and lowering the cutting unit 5 is provided. Fig.10 ).

[0068] The operation of the control valve of the reaping lift cylinder 18 is controlled by the manual operation of the reaping lift rod 35 and the control device 200, and the reaping section 5 is raised and lowered. The reaping lift rod 35 is operated from the neutral position to the raising side to control the reaping lift cylinder 18 to extend, thereby raising the reaping section 5. The reaping lift rod 35 is operated from the neutral position to the lowering side to control the reaping lift cylinder 18 to contract, thereby lowering the reaping section 5. The operation section for adjusting the reaping height may be composed of an operation member other than a lever, such as a switch operation section (reaping lift switch).

[0069] In addition, as an operation unit for operating the harvesting unit 5, the driving unit 14 is provided with: a harvesting automatic lifting switch 36 that raises the harvesting unit 5 to a predetermined height position; and a harvesting automatic setting switch 37 that lowers the harvesting unit 5 to a predetermined height position. After the engine 11 is started, the harvesting automatic lifting switch 36 is turned on in a state where the harvesting clutch is engaged, so that the harvesting unit 5 is automatically raised to a predetermined height position set in advance with the extension drive of the harvesting lifting cylinder 18. In addition, after the engine 11 is started, the harvesting automatic setting switch 37 is turned on in a state where the harvesting clutch is engaged, so that the harvesting unit 5 is automatically lowered to a predetermined height position set in advance with the contraction drive of the harvesting lifting cylinder 18. The harvesting automatic lifting switch 36 and the harvesting automatic setting switch 37 are arranged on the main gear lever 17 as operation buttons, for example. In the raising and lowering of the harvesting unit 5 based on the above switch operations, the raising and lowering operation of the harvesting unit 5 based on the operation of the harvesting lifting lever 35 is given priority. The harvesting clutch is brought into an engaged state by operating a clutch operating tool such as a working clutch lever disposed on the driving unit 14 .

[0070] In the present embodiment, the cutting height detection device 40 is arranged on the rear side of the second and sixth crop separation boards 21A from the left among the seven crop separation boards 21 (see Figure 3 ). The straw separating plate 21A is supported by a straw separating frame 34 having a shape different from that of the other straw separating frames 32. The straw separating plate 21A is the smaller straw separating plate 21 of the two types of straw separating plates 21. In this way, the combine harvester 1 has two cutting height detection devices 40. However, the number of cutting height detection devices 40 that the combine harvester 1 has and the positions where the cutting height detection devices 40 are set are not limited. The cutting height detection device 40 can be set, for example, at a location on the rear side of the straw separating plate 21 at the left end or the right end.

[0071] [Structure of cutting height detection device]

[0072] use Figures 4 to 9 The structure of the cutting height detection device 40 is described. Figures 4 to 9 As shown, the cutting height detection device 40 includes a device body 41 , a grounding body 42 , a cutting height sensor 43 as a sensor for detecting the cutting height, and a unit support body 44 as a member for supporting the device body 41 .

[0073] The cutting height detection device 40 is composed of a device body 41, a grounding body 42, and a cutting height sensor 43, which constitute an integrated sensor unit 45 (see Fig. 9), the sensor unit 45 is supported on the unit support body 44 in a manner that can rotate around an axis in the left-right direction. The unit support body 44 is supported on the grass dividing portion 50 in a manner that can rotate around an axis in the front-back direction.

[0074] The cutting height detection device 40 as a whole is supported by the crop separation part 50 so as to be rotatable around an axis in the front-back direction, and the sensor unit 45 is supported by the unit support body 44 so as to be rotatable around an axis in the left-right direction. The cutting height detection device 40 is rotated around the axis in the front-back direction, and the sensor unit 45 is rotated around the axis in the left-right direction according to the external force acting on the cutting height detection device 40. Hereinafter, the cutting height detection device 40 which is basically in the reference state will be described, with the state in which the external force does not act on the cutting height detection device 40 being set as the reference state.

[0075] Regarding the sensor unit 45, the device body 41 has a structure in which various gears, springs, etc. are supported on a predetermined axis in a housing 51 made of a metal casting, for example. The housing 51 has a left-right half-split structure consisting of a right housing 52 constituting the main body of the housing 51 and a left housing 53 covering the left side of the right housing 52 in a cover-like manner. The right housing 52 and the left housing 53 are fixed to each other by fixing bolts 55 at four locations around the housing 51 when viewed from the side. The housing 51 has a front-to-back direction ( Figure 6 The housing 51 is formed into a substantially rectangular shape with its long side (in the left-right direction) being the long side direction. The housing 51 is formed into a mountain shape with its upper side convex toward the upper side when viewed from the side.

[0076] Regarding the sensor unit 45, the grounding body 42 protrudes downward from the rear side of the rear end of the housing 51. In addition, the cutting height sensor 43 is provided so as to be attached to the right side surface of the housing 51.

[0077] The unit support body 44 is a member formed by bending a narrow plate-like member so as to form a predetermined shape in a plan view, and extends in the front-rear direction. Figure 8 As shown, the unit support body 44 includes a first support body 46 which mainly constitutes a left portion of the unit support body 44 , and a second support body 47 which mainly constitutes a right portion of the unit support body 44 .

[0078] The unit support body 44 has a left side surface 44a which is elongated in the front-to-back direction; a front surface 44b which is formed at a right angle from the front end of the left side surface 44a toward the right side; and a right side surface 44c which is formed from the right end of the front surface 44b toward the rear and is elongated in the front-to-back direction. The above-mentioned surfaces constituting the unit support body 44 are all longitudinal surfaces. That is, the first support body 46 and the second support body 47 are both plate-shaped members which are bent and formed in a manner to form a predetermined shape when viewed from above, and the left side surface 44a, the front surface 44b, and the right side surface 44c are formed by the above-mentioned support bodies.

[0079] like Figure 8 As shown, the first support body 46 has: an outer wall surface 46a, which constitutes the left side surface 44a of the unit support body 44; a front wall surface 46b, which constitutes a part of the front surface 44b of the unit support body 44; and an inner wall surface 46c, which is formed at a right angle from the right end of the front wall surface 46b toward the rear. The first support body 46 is formed by the outer wall surface 46a, the front wall surface 46b and the inner wall surface 46c into a curved shape that is approximately "J"-shaped when viewed from above. In addition, as shown Figure 8 As shown, the second support body 47 has: a side wall surface 47a, which constitutes the right side surface 44c of the unit support body 44; a front side wall surface 47b, which constitutes a part of the front surface 44b of the unit support body 44; and a sloped wall surface 47c, which is formed at the corner formed by the side wall surface 47a and the front side wall surface 47b and is formed into a chamfered shape when viewed from above.

[0080] The left side surface 44a of the unit support body 44 (the outer side wall surface 46a of the first support body 46) is a plate-shaped portion that is elongated in the front-to-back direction and has a plate thickness direction in the left-right direction. The left side surface 44a is arranged such that the rear end portion thereof is positioned further rearward than the rear end portion of the housing 51 in the front-to-back direction. The front surface 44b of the unit support body 44 is a plate-shaped portion that has a plate thickness direction in the front-to-back direction. The front surface 44b is formed by the front side wall surface 46b of the first support body 46 and the front side wall surface 47b of the second support body 47.

[0081] The first support body 46 and the second support body 47 are connected to each other by fastening and fixing by a threaded body 48 and a nut 49 that penetrate the overlapping portion of the front side wall surface 46b, 47b. The threaded body 48 has a threaded portion that protrudes forward from the front side wall surface 47b of the second support body 47, and the nut 49 is screwed into the protruding portion. The fixing portion based on the threaded body 48 is provided at two locations, one above and one below.

[0082] The right side surface 44c of the unit support body 44 (the side wall surface 47a of the second support body 47) is a plate-shaped portion that is elongated in the front-to-back direction and has the plate thickness direction in the left-right direction, and is disposed opposite to the left side surface 44a in the left-right direction. The rear end of the right side surface 44c is disposed at a position that is substantially the same as the rear end of the housing 51 in the front-to-back direction.

[0083] The unit support body 44 is open in the vertical direction, and has a substantially rectangular shape in a plan view with the front-to-back direction being the long side direction due to the left side surface 44a, the front surface 44b, and the right side surface 44c. The unit support body 44 is arranged so that the left side surface 44a, the front surface 44b, and the right side surface 44c are respectively located at the sensor unit 45 (see Fig. 9 ), thereby forming a peripheral wall portion surrounding the periphery of the sensor unit 45. That is, the sensor unit 45 is provided so that it is substantially entirely located in the space portion surrounded by the unit support body 44 when viewed from above. The sensor unit 45 is substantially entirely located inside the unit support body 44 in the front-rear direction and the left-right direction.

[0084] The various parts of the sensor unit 45 are described. The device body 41 is provided on the front fixed shaft 61 as the first shaft so as to be able to rotate up and down. The front fixed shaft 61 is a support shaft with the left and right directions as the axial direction, and supports the sensor unit 45 so as to be able to rotate around the first axis P1 (see Figure 6 , Figure 8 ).

[0085] The front fixed shaft 61 is located near the front end of the shell 51 in the device body 41. The front fixed shaft 61 is fixed to the inner wall surface 46c of the first support body 46 by means of the support plate 56 so that the right end protrudes from the inner wall surface 46c toward the left. The front fixed shaft 61 is a fixed shaft supported on the inner wall surface 46c in a cantilevered manner. The support plate 56 is fixed at two upper and lower locations by bolts 57 in a state overlapping with the inner side (left side) of the inner wall surface 46c. In addition, the front fixed shaft 61 only needs to be a shaft fixed to the unit support body 44. The front fixed shaft 61 is supported by the shell 51 in a relatively rotatable manner. That is, the shell 51 is supported so as to be rotatable relative to the front fixed shaft 61.

[0086] Thus, the sensor unit 45 is provided in a cantilevered state with the left-right direction being the axial direction so as to be able to rotate up and down on the front fixed shaft 61 (see Figure 6 , arrow A1). That is, the unit support body 44 supports the device body 41 of the sensor unit 45 by the front side fixed shaft 61 so as to be able to rotate up and down around the first axis P1.

[0087] Regarding the rotation of the sensor unit 45 relative to the unit support body 44 around the first axis P1, the sensor unit 45 is forced in the downward rotation direction (right rotation direction when viewed from the left) by an elastic member such as a spring provided in the housing 51, i.e., a housing reset member. The housing reset member is, for example, a torsion spring having linear extensions formed at both ends of a coil-shaped main body. In this case, the housing reset member allows the front fixed shaft 61 to penetrate the main body, and is set in a state where one extension is locked on the front fixed shaft 61 side and the other extension is locked on the housing 51 side, thereby causing a force that presses the housing 51 downward relative to the front fixed shaft 61 side to act. As a result, the sensor unit 45 is forced in the downward rotation direction around the front fixed shaft 61.

[0088] In addition, a housing return spring 58 (see FIG. 5 ) is provided at a portion of the front fixed shaft 61 that protrudes to the right from the housing 51 to bias the sensor unit 45 in a downward rotation direction relative to the front fixed shaft 61. Figure 8 The housing return spring 58 is a torsion spring having a coil-shaped main body with linear extensions 58a formed at both ends thereof.

[0089] The housing return spring 58 allows the front fixed shaft 61 to penetrate the main body, and is arranged so that one extension 58a is inserted and locked in the locking hole 52a formed on the right side of the front part of the right housing 52 of the housing 51 (see Figure 7 ), and the other extension 58a is locked to the front surface 44b of the unit support body 44 in a predetermined manner, so that a force that presses the housing 51 downward relative to the front fixed shaft 61 is exerted. As a result, the sensor unit 45 is forced in a direction to rotate downward around the front fixed shaft 61.

[0090] On the other hand, regarding the rotation of the sensor unit 45 relative to the unit support body 44, the downward rotation of the sensor unit 45 is restricted by the case stopper bolt 59 provided on the case 51 at the position of the reference state. The case stopper bolt 59 is screwed into the front-rear middle part of the upper edge of the left case 53 from the left side so that the head thereof protrudes from the left case 53 toward the left side.

[0091] According to this structure, in the reference state, the sensor unit 45 makes the head of the housing stopper bolt 59 contact the upper edge of the left side surface 44a of the unit support body 44 and cannot rotate downward relative to the unit support body 44. In addition, the locking portion of the sensor unit 45 relative to the unit support body 44 may be a protrusion formed as a part of the left housing 53.

[0092] In this way, regarding the rotation about the front fixed shaft 61, the sensor unit 45 is restricted from rotating downward relative to the unit support body 44 from the reference state in a state where a force is applied in the downward rotation direction. Therefore, an external force from the ground 30 or the like that rotates the sensor unit 45 upward about the front fixed shaft 61 acts on the sensor unit 45, and the sensor unit 45 rotates upward against the acting force of the housing return member and the housing return spring 58 in the housing 51. The sensor unit 45 in the state of rotating upward automatically rotates downward by the acting force of the housing return spring 58 or the like when the external force is released, and returns to the position of the reference state by the locking action of the housing stopper bolt 59 relative to the unit support body 44.

[0093] The grounding body 42 is supported rotatably by a second shaft, namely a rear rotation shaft 62, which is located behind the front fixed shaft 61 relative to the device body 41. The rear rotation shaft 62 is a support shaft with the axial direction set in the left and right directions, and supports the grounding body 42 to be rotatable relative to the housing 51 of the device body 41 around the second axis P2.

[0094] The rear rotating shaft 62 is located near the rear end of the housing 51, and is supported by a bearing member such as a sleeve so as to be relatively rotatable with respect to the housing 51. A grounding body 42 is fixedly provided at a portion of the rear rotating shaft 62 that protrudes to the right from the housing 51. The grounding body 42 includes a grounding body main body 42a, which is a portion extending downward from the device main body 41, and a support arm 42b, which is a support portion with respect to the rear rotating shaft 62. The grounding body main body 42a and the support arm 42b are both plate-shaped portions having a predetermined shape.

[0095] The grounding body main body 42a is a scraper-shaped portion having a downwardly extending shape with a width (dimension in the left-right direction) gradually increasing from the upper side to the lower side. The support arm 42b extends from the upper end of the grounding body main body 42a located directly behind the housing 51 to the right front side along the housing 51 and is fixed to the rear rotating shaft 62. The support arm 42b allows the right end of the rear rotating shaft 62 to pass through its front part and is fastened to the rear rotating shaft 62 by a nut 68 or the like. A threaded portion that receives the screwing of the nut 68 is formed at the right end of the rear rotating shaft 62.

[0096] In this way, the grounding body 42 is fixed to the rear rotating shaft 62 and rotates integrally with the rear rotating shaft 62 around the second axis P2. The grounding body 42 is set so as not to interfere with the housing 51 within its rotation range. Regarding the rotation position of the grounding body 42, the position of the grounding body 42 of the cutting height detection device 40 in the reference state is set as the reference position.

[0097] The grounding body 42 rotates as follows as a relative rotation about the rear rotation axis 62 with respect to the device body 41. That is, the grounding body 42 rotates (rotates backward) in a state where the end is in contact with the ground 30 due to the drag resistance (ground sliding resistance) from the ground 30 caused by the forward movement of the combine harvester 1 so that the end side moves backward (rotates backward) (see Figure 6 On the other hand, the grounding body 42 rotates (rotates forward) so that the end side moves forward due to the grounding sliding resistance caused by the combine harvester 1 moving backward (refer to Figure 6 , arrow C2).

[0098] The cutting height sensor 43 is a sensor for detecting the rotation amount of the grounding body 42 around the rear rotation axis 62. The cutting height sensor 43 is provided relative to the intermediate rotation axis 70, which is the third axis of the cutting height detection device 40, and detects the rotation amount of the grounding body 42 around the rear rotation axis 62 according to the rotation amount of the intermediate rotation axis 70.

[0099] The intermediate rotating shaft 70 is a support shaft with the left-right direction as the axial direction, and is supported by the housing 51 of the device body 41 in a manner that it can rotate relatively around the third axis P3 by means of a bearing member such as a sleeve. The intermediate rotating shaft 70 is located between the front fixed shaft 61 and the rear rotating shaft 62 in the front-back direction.

[0100] The cutting height sensor 43 is a rotary potentiometer, and detects the rotation position of the grounding body 42 by means of the intermediate rotating shaft 70 and the rear rotating shaft 62. The cutting height sensor 43 is fixed to the right housing 52 by bolts 73 at two locations above and below the right side of the right housing 52 (see Figure 7 ).

[0101] The cutting height sensor 43 is connected to the right end of the intermediate rotating shaft 70, and directly detects the rotation position of the intermediate rotating shaft 70 around the third axis P3 by using the intermediate rotating shaft 70 as a detection axis. The cutting height sensor 43 has: a main body 43a; and a connector 43b, which connects a signal line to the main body 43a. One end side of a harness (not shown) as a signal line is connected to the connector 43b. The cutting height sensor 43 is connected to the control device 200 provided on the travel machine body 4 side by the harness. In addition, as a connection structure with respect to the control device 200, the cutting height sensor 43 may have a structure in which the signal line is directly extended from the main body.

[0102] The intermediate rotating shaft 70 rotates by receiving the transmission of the rotational power of the rear rotating shaft 62 accompanying the rotation of the grounding body 42. The intermediate rotating shaft 70 receives the transmission of the rotational power of the rear rotating shaft 62 by means of gears and the like provided on the rear rotating shaft 62 and each shaft of the intermediate rotating shaft 70. The rotation of the intermediate rotating shaft 70 is detected by the cutting height sensor 43. In addition, the grounding body 42 is provided to be positioned at a predetermined reference position in a state where no external force is applied, by setting the force (torque) of the grounding body reset member, the housing reset member, etc., in relation to the rotation around the rear rotating shaft 62, using an elastic member such as a spring provided in the housing 51, i.e., a grounding body reset member.

[0103] Regarding the cutting height detection device 40 having the above structure, the grounding body 42 is arranged to rotate around the rear rotation axis 62 relative to the device body 41 in a state where the rotation around the front fixed axis 61 is stopped when the grounding body 42 is located at a position further rearward than the reference position. That is, for example, when the body of the combine harvester 1 is moving forward, when the grounding body 42 is pressed from the front and rotates further rearward than the reference position, the device body 41 does not rotate around the front fixed axis 61, and only the grounding body 42 rotates relatively around the rear rotation axis 62 relative to the device body 41.

[0104] The cutting height sensor 43 detects the amount of rotation of the grounding body 42 from the reference position to the rear. That is, the grounding body 42 is rotated relative to the device body 41 to the rear from the state where the grounding body 42 is at the reference position, and the cutting height sensor 43 detects the rotation for detecting the cutting height.

[0105] On the other hand, regarding the relative rotation of the grounding body 42 with respect to the device body 41, the rotation of the grounding body 42 from the reference position to the front is accompanied by the upward rotation of the housing 51. That is, during the rotation of the grounding body 42 from the reference position to the front, the device body 41 as a whole rotates upward around the front fixed shaft 61 in conjunction with the rotation of the grounding body 42. Here, during the relative rotation of the grounding body 42 with respect to the device body 41 from the reference position to the front, the intermediate rotation shaft 70 does not rotate, and the rotation of the intermediate rotation shaft 70 is not detected by the cutting height sensor 43.

[0106] As described above, the cutting height detection device 40 is configured to detect the rotation amount of the grounding body 42 using the cutting height sensor 43 when the grounding body 42 is rotated backward from the reference position relative to the device body 41 .

[0107] According to the cutting height detection device 40 having the above-mentioned structure, the combine harvester 1 detects the height (cutting height) of the cutting section 5 based on the detection signal of the cutting height sensor 43. As described above, the cutting height detection device 40 detects the rearward rotation of the ground contact body 42, and therefore, the cutting height is mainly detected when the body of the combine harvester 1 moves forward.

[0108] Regarding the cutting height detection device 40, the cutting height sensor 43 detects the rotation position of the intermediate rotating shaft 70 that rotates in conjunction with the rotation of the ground body 42, thereby detecting the height of the grass-dividing plate 21 relative to the ground 30, that is, the cutting height. The detection signal of the cutting height sensor 43 is transmitted to the control device 200 by a wire harness. The control device 200 receives the input of the detection signal from the cutting height sensor 43, and based on the detection signal, controls the cutting lifting cylinder 18 (see FIG. 1 ) in such a way that the cutting height calculated based on the detection result is maintained at a set value. Figure 1 ) to perform the action and adjust the cutting height.

[0109] Regarding the structure in which the cutting height sensor 43 is attached to the outside of the housing 51 of the device body 41, a sensor cover 170 covering the cutting height sensor 43 is provided in the device body 41. The sensor cover 170 is fixed to the housing 51 by bolts 176.

[0110] [Support structure of cutting height detection device]

[0111] use Figures 4 to 8 The support structure of the cutting height detection device 40 is described. The cutting height detection device 40 is supported by the support structure of the unit support body 44 for the grain separation part 50 so as to be able to move along the axis line O1 (see Figure 6 , Figure 8 ) as the center and rotates in a swinging manner in the left and right directions.

[0112] like Figures 4 to 8 As shown, the grass dividing portion 50 includes: a grass dividing frame 34, which is arranged at the lower part of the cutting portion 5; and a grass dividing plate 21, which is arranged at the front side of the grass dividing frame 34. Here, the grass dividing plate 21 and the grass dividing frame 34 related to the support of the cutting height detection device 40 are the second and sixth grass dividing plates 21A and grass dividing frames 34 from the left side, respectively (refer to Figure 3 ).

[0113] The straw dividing frame 34 has, from the rear end side to the front end side: a rear inclined portion 101, which is an inclined portion that is lower at the front and higher at the rear; an intermediate horizontal portion 102, which is a horizontal portion; and a front inclined portion 103, which is an inclined portion that is higher at the front and lower at the rear and that forms an obtuse-angled corner together with the intermediate horizontal portion 102. The intermediate horizontal portion 102 and the front inclined portion 103 form a curved corner 104. The straw dividing frame 34 sets the rear end portion of the rear inclined portion 101 as the base end portion, and sets the front end portion of the front inclined portion 103 as the terminal end portion. The straw dividing frame 34 makes the rear end portion of the rear inclined portion 101 located above the transverse frame 31, and fixes the rear inclined portion 101 to the transverse frame 31 by means of a prescribed support member 105 fixedly provided on the transverse frame 31 (refer to Figure 4 ).

[0114] The straw-dividing plate 21 has: a straw-dividing plate body 121; and a rib portion 122, which is arranged on the rear side of the straw-dividing plate body 121. The straw-dividing plate body 121 is a plate-shaped component whose front side is set as a convex side when viewed in a plan view and in cross-section, and has a sharp front end shape that gradually narrows from the rear side to the front side when viewed from the front and in a plan view. The straw-dividing plate body 121 has a curved shape in which the front is low and the rear is high, and the rear lower side is set as a convex side when viewed from the side. The rib portion 122 is a plate-shaped portion whose left and right directions are set as the plate thickness direction, and is set as a portion integral with the straw-dividing plate body 121 on the rear side of the front plate portion of the straw-dividing plate body 121. The structure in which the rib portion 122 is provided on the straw-dividing plate body 121 has a shape that is approximately symmetrical on the left and right.

[0115] In addition, the grass-separating portion 50 includes a claw 125 as a grass-separating plate supporting member provided on the rear side of the grass-separating plate 21. The claw 125 is a long plate-like member, and is arranged in an inclined shape with a high back and a low front so that its long side direction is along the slope of the grass-separating plate 21 with a high back and a low front. The claw 125 is fixed to the grass-separating frame 34 by means of a claw supporting plate 124. The claw supporting plate 124 is a plate-like member whose left and right directions are arranged in the direction of the plate thickness, and is fixed to the front inclined portion 103 of the grass-separating frame 34 by welding or the like.

[0116] The claw 125 is fastened to the claw support plate 124 at two locations in the front and rear by bolts 127 and nuts 128 in a state where the rear portion overlaps with the claw support plate 124 from the left side. The grain-dividing plate 21 is mounted on the claw 125. The grain-dividing plate 21 is fastened to the claw 125 at two locations in the front and rear by bolts 141 and nuts 142 in a state where the rear portion of the rib plate portion 122 overlaps with the front portion of the claw 125 from the right side. In this way, the claw 125 is fixed to the grain-dividing frame 34 and supports the grain-dividing plate 21 in front of the grain-dividing frame 34.

[0117] The cutting height detection device 40 is supported on the crop separation part 50 having the above structure in a manner that it can rotate around an axis in the front-back direction. The cutting height detection device 40 has an axis support part 130 as a support part for the crop separation part 50 on its front side, and is supported by the axis support part 130 so as to be rotatable around the axis center line O1 in the front-back direction as the rotation axis.

[0118] The shaft support portion 130 is provided at the rear side of the crop separation plate 21. The shaft support portion 130 includes: a boss portion 132, which is a support portion provided at the rear side of the crop separation plate 21; and a support shaft portion 131, which is provided at the front end portion of the unit support body 44 and supported by the boss portion 132. The shaft support portion 130 has a structure in which the support shaft portion 131 protruding from the front side wall surface portion 46b of the front surface portion 44b of the unit support body 44 toward the front is supported by the boss portion 132 provided at the lower end portion of the claw 125. That is, the front end side of the cutting height detection device 40 is mounted on the claw 125 by means of the boss portion 132.

[0119] The support shaft portion 131 is a part integral with the unit support body 44 and protrudes forward from the front wall surface portion 46b, with the axis aligned with the axis center line O1. The boss portion 132 is a hollow cylindrical portion with an open rear side, and is provided by fixing a cylindrical member to the lower end of the claw 125. The support shaft portion 131 is rotatably supported on the boss portion 132 by a bearing member such as a sleeve, with the front portion inserted into the boss portion 132, and is secured against disengagement with respect to the boss portion 132 by a fixing screw 137 and a lock nut 138 (see FIG. 1 ). Figure 8 ).

[0120] In this way, the shaft support portion 130 supports the support shaft portion 131 provided at the front portion of the unit support body 44 on the grain separation plate 21 by means of the claw 125 and the boss portion 132. Thus, the shaft support portion 130 supports the front side of the cutting height detection device 40 relative to the grain separation portion 50 so that it can rotate with the front-rear direction as the rotation axis. The cutting height detection device 40 is cantilever-supported by the shaft support portion 130 relative to the grain separation portion 50.

[0121] As described above, the cutting height detection device 40 supports the unit support body 44 relative to the grain separating part 50 so as to be rotatable about the axis line O1 in the front-rear direction, thereby supporting the sensor unit 45 supported by the unit support body 44 so as to be swingable left and right.

[0122] Regarding the rotation about the axis in the front-rear direction, the cutting height detection device 40 is elastically positioned in a predetermined neutral position by a return spring 147 provided on the shaft support portion 130. The return spring 147 is a so-called torsion spring, and the rear portion of the boss portion 132 passes through the coil-shaped portion and is locked to a locking pin 148 provided above the boss portion 132 and protruding from the front side wall surface 46b toward the front.

[0123] The return spring 147 makes the extensions 147a at both ends be located on the left and right sides of the locking pin 148, and the extensions 147a are used to clamp the locking pin 148 from the left and right sides with elastic force. In addition, the return spring 147 makes the extensions 147a be located on the left and right sides of the lower part of the claw 125 located above the locking pin 148, and the claw 125 is clamped by the left and right extensions 147a with elastic force.

[0124] According to this structure, when an external force of a predetermined magnitude or more that rotates the cutting height detection device 40 about the axis O1 acts on the cutting height detection device 40, the cutting height detection device 40 rotates while overcoming the elastic force of the return spring 147 in a state where one of the extensions 147a is pressed by the locking pin 148 in accordance with the rotation direction and the other extension 147a is locked to the claw 125. When the external force disappears, the cutting height detection device 40 returns to the neutral position by the elastic force of the return spring 147.

[0125] [Operation of cutting height detection device]

[0126] The operation of the cutting height detection device 40 will be described. During normal operation of the combine harvester 1, that is, operation in the forward state of the machine body, the cutting height is controlled so as to maintain the cutting height at a set value based on the detection value of the cutting height of the cutting height detection device 40. The cutting height is detected in a state where the rotation position of the grounding body 42 relative to the machine body 41 is further rearward than the reference position.

[0127] When the machine body moves forward, the grounding body 42, which slides with the end in contact with the ground 30, rotates backward from the reference position around the rear rotation axis 62 relative to the housing 51 of the device body 41 due to the grounding sliding resistance (see Figure 6 The grounding body 42 rotates integrally with the rear rotating shaft 62 around the second axis P2. The rotation of the rear rotating shaft 62 is transmitted to the intermediate rotating shaft 70 by means of gears, etc. The rotation of the intermediate rotating shaft 70 is detected by the cutting height sensor 43. The cutting height is detected based on the rotation amount of the intermediate rotating shaft 70.

[0128] In addition, for example, when the machine body is turned while the grounding body 42 is grounded, if a lateral external force acts on the cutting height detection device 40, the cutting height detection device 40 avoids the lateral external force by rotating around the axial center line O1 in the front-rear direction by the shaft support part 130. When the lateral external force on the cutting height detection device 40 disappears, the urging structure based on the return spring 147 and the locking pin 148 returns the cutting height detection device 40 to a predetermined neutral position.

[0129] [Control structure of a combine harvester]

[0130] use Fig.10 The control structure of the combine harvester 1 is described. Fig.10 As shown, the combine harvester 1 is provided with a control device 200. The control device 200 controls various parts of the combine harvester 1 based on input signals from various sensors and the like provided by the combine harvester 1. The control device 200 has a structure in which a CPU (Central Processing Unit) as an operation processing device that performs various operation processing and control, a storage device such as a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output device (input / output circuit) such as an input / output interface for data input / output, a peripheral circuit such as a clock circuit, and the like are connected by a bus or the like. The CPU of the control device 200 performs operation processing according to various programs stored in the ROM or the like.

[0131] like Fig.10 As shown, as a structure electrically connected to the input device (input circuit) of the control device 200, in addition to the cutting height sensor 43 of the cutting height detection device 40, the combine harvester 1 further includes a vehicle speed sensor 201, a cutting height adjustment dial 202 as a cutting height target value setting operation unit, an automatic cutting height switch 205, a machine height sensor 203, and a stalk detection sensor 204. The control device 200 receives inputs of signals from the above sensors, switches, etc., and generates control signals based on the above signals.

[0132] The machine body height sensor 203 is provided on a shaft support portion that supports the cutting unit 5 to be rotatable about a predetermined rotation axis along the left-right direction relative to the traveling machine body 4. The machine body height sensor 203 is a machine body position sensor for detecting the height of the cutting unit 5 relative to the traveling machine body 4, that is, the machine body height (machine body main body height). The machine body height sensor 203 is, for example, a rotary type potentiometer, and detects the rotation position of the cutting unit 5 by means of the rotation axis of the cutting unit 5 relative to the traveling machine body 4, etc.

[0133] The vehicle speed sensor 201 is a sensor for detecting the travel speed of the combine harvester 1 (traveling machine body 4), that is, the vehicle speed. The control device 200 receives the input of the detection signal from the vehicle speed sensor 201 and monitors the vehicle speed. The control device 200 controls the vehicle speed based on the detection signal of the vehicle speed sensor 201. The control device 200 is configured to calculate the travel distance of the combine harvester 1 based on the detection information of the vehicle speed sensor 201 and the time elapsed information.

[0134] As a driving unit 220 related to the vehicle speed, the combine harvester 1 has a traveling HST for changing the travel speed. Here, "HST" refers to a hydraulic continuously variable transmission device that uses a method of converting the hydraulic pressure generated by driving a hydraulic pump into a rotational force again using a hydraulic motor. The HST has a variable volume pump and a motor connected to each other by a fluid, and electromagnetic valves corresponding to the pump and the motor, respectively, and an output shaft. In the HST, the power from the engine 11 is received and the pump is adjusted and driven (travel drive adjustment) by the electromagnetic valve for the pump, and the drive of the motor based on the adjustment drive is transmitted to the output shaft.

[0135] The output shaft of the HST for traveling is interlocked with a transmission mechanism for transmitting driving force to the left and right crawler parts 3, 3 constituting the traveling part 2. The transmission mechanism is composed of a planetary gear set and has left and right output shafts for transmitting driving force to the drive sprockets 3b of the left and right crawler parts 3.

[0136] The control device 200 receives an input of a detection signal regarding the front-rear rotation operation position (operation amount) of the main gear lever 17, generates control information based on the detection signal, and controls the drive of the drive unit 220 based on the generated control information. The operation amount of the main gear lever 17 is detected by, for example, a rotary encoder, a rotary potentiometer, etc. The control device 200 controls the solenoid valve for the HST to control the drive of the pump and the motor, and controls the power transmission from the output shaft to the transmission mechanism.

[0137] In this structure, the vehicle speed sensor 201 detects, for example, the rotation speed of the crawler 3 or the rotation speed of the output shaft of the HST for traveling as the vehicle speed. The control device 200 controls the drive unit 220 so that the vehicle speed detected by the vehicle speed sensor 201 reaches a speed corresponding to the manual operation of the main gear lever 17 or the like.

[0138] The control device 200 controls the lifting and lowering of the harvesting section 5 by operating the harvesting lift cylinder 18 so as to maintain the harvesting height at the harvesting height target value based on the detection signal from the harvesting height sensor 43. The control device 200 controls the operation of the solenoid valve 221 for hydraulic control of the harvesting lift cylinder 18 to control the extension and retraction operation of the harvesting lift cylinder 18.

[0139] The control device 200 sets and stores a target value of the cutting height for controlling the lifting and lowering of the cutting section 5. The setting of the target value of the cutting height for the control device 200 is performed by the cutting height adjustment dial 202.

[0140] like Fig.11 As shown, the cutting height adjustment dial 202 is provided as one of the operating parts of the operating part group 300 provided on the upper surface of the side column 19 in the side operating part 12 provided on the left side of the driver's seat 16 of the driving part 14, and is operated by the operator sitting on the driver's seat 16. The cutting height adjustment dial 202 is an operating member for adjusting the target value of the cutting height in a stepwise manner, and is provided as a cylindrical protrusion (knob) that is rotated. In the present embodiment, it is configured to be able to adjust the target value of the cutting height in five levels within the range of 10 to 50 mm, for example.

[0141] As described above, the combine harvester 1 comprises: a harvesting section 5, which is arranged to be able to be raised and lowered relative to the traveling body 4; a harvesting height detection device 40, which is used to detect the height of the harvesting section 5 above the ground, that is, the harvesting height; a machine body height sensor 203 as a machine body height detection device, which is used to detect the height of the harvesting section 5 relative to the traveling body 4, that is, the machine body height; and a control device 200, which controls the height of the harvesting section 5 based on the detection signals of the harvesting height detection device 40 and the machine body height sensor 203.

[0142] [Lifting and lowering control of the cutting section]

[0143] The lifting control of the harvesting section 5 by the control device 200 in the combine harvester 1 having the above structure is described. In the lifting control of the harvesting section 5 involved in this embodiment, for example, the detection signal of the lower harvesting height is used among the detection signals of the two harvesting height detection devices 40. However, the use of the two harvesting height detection devices 40 is not particularly limited.

[0144] The control device 200 performs two types of control, namely, a harvesting height control as a first control and a lifting range limitation control as a second control as the lifting control of the harvesting section 5. Basically, the above-mentioned controls are performed in parallel during harvesting work by the combine harvester 1.

[0145] The cutting height control is explained. The cutting height control is a control based on the detection signal of the cutting height detection device 40, and is a control including the automatic control of the cutting height. As the control mode of the cutting height control, the control device 200 has an automatic cutting height mode as a first control mode for automatically controlling the cutting height, and an automatic raising mode as a second control mode for raising the cutting section 5 to a constant height according to a predetermined condition. Hereinafter, the cutting height control including the control of the above two control modes and based on the detection signal of the cutting height detection device 40 is referred to as "automatic cutting height control".

[0146] The automatic cutting height mode of the automatic cutting height control is a mode in which the height of the cutting section 5 is controlled so that the cutting height detected by the cutting height detection device 40 reaches a predetermined target value (cutting height target value), and the height of the cutting section 5 is kept at a constant height relative to the ground 30 during the cutting operation. The automatic raising mode of the automatic cutting height control is a mode in which, based on the cutting height detected by the cutting height detection device 40, when the height of the cutting section 5 relative to the ground 30 is lower than a set height during the cutting operation, the cutting section 5 is raised to a constant height.

[0147] The automatic cutting height switch 205 functions as a mode switching switch for switching between the automatic cutting height mode and the automatic raising mode of the automatic cutting height control. Fig.11 As shown in FIG. 1 , in the operation unit group 300, as an operation unit for adjusting the cutting height and setting the cutting height adjustment dial 202, an automatic cutting height switch 205 is arranged near the cutting height adjustment dial 202. In the present embodiment, the automatic cutting height switch 205 is an operation unit for performing a pressing operation and is arranged on the right side of the cutting height adjustment dial 202 ( Fig.11 ).

[0148] A mode display unit 206 for displaying the current control mode is provided near the automatic cutting height switch 205. The mode display unit 206 includes a first display unit 206a for displaying the text "Automatic cutting height" corresponding to the automatic cutting height mode, and a second display unit 206b for displaying the text "OK rise" corresponding to the automatic rise mode. The first display unit 206a and the second display unit 206b are configured to flash, and are configured to light up in accordance with the control mode selected by the operation of the automatic cutting height switch 205. In addition, the automatic cutting height control is turned off when neither the automatic cutting height mode nor the automatic rise mode is selected by the operation of the automatic cutting height switch 205. In the state where the automatic cutting height control is turned off, both the first display unit 206a and the second display unit 206b are turned off. That is, by operating the automatic cutting height switch 205, switching is performed between three states: the state of the automatic cutting height mode of the automatic cutting height control, the state of the automatic raising mode of the automatic cutting height control, and the state of the automatic cutting height control being turned off.

[0149] When the operation is performed in the automatic cutting height mode, the automatic cutting height mode is selected by operating the automatic cutting height switch 205 while the engine 11 is started. Fig.12 As shown in A, the first display unit 206a is turned on and the second display unit 206b is turned off.

[0150] The cutting operation is started in the state where the automatic cutting height mode is selected. During the cutting operation, the cutting height adjustment dial 202 is adjusted to any scale from "1" to "5". Fig.12 In the example shown in A, the cutting height adjustment dial 202 is set to the scale of "3". Thus, the cutting height corresponding to the scale set by the cutting height adjustment dial 202 is set as the cutting height target value, and the cutting height is automatically controlled to be maintained at the cutting height target value based on the detection signal of the cutting height detection device 40.

[0151] When the work is performed in the automatic raising mode, the automatic raising mode is selected by operating the automatic cutting height switch 205 while the engine 11 is started. Fig.12 As shown in B, the second display unit 206b is turned on and the first display unit 206a is turned off.

[0152] When the cutting operation is started in the state where the automatic raising mode is selected, during the cutting operation, if the cutting height detected by the cutting height detection device 40 is detected to be below the set height (e.g., 10 mm), the cutting section 5 is automatically controlled to rise by a predetermined amount (e.g., 1 to 2 cm). In addition, in the state where the automatic raising mode is selected, if it is detected that the machine body is stopped in driving, or the cutting height detected by the cutting height detection device 40 reaches or exceeds another set height (e.g., 20 mm), the rising of the cutting section 5 is controlled to stop. The set height and the predetermined amount for the automatic raising mode are preset and stored in the control device 200.

[0153] The lifting range limiting control is described below. The lifting range limiting control limits the lifting range of the cutting unit 5 within a predetermined range of lifting and lowering amounts relative to a cutting reference height, which is a reference value of the machine height detected by the machine height sensor 203. The cutting reference height is stored in the control device 200.

[0154] The cutting reference height is, for example, a relative machine height stored when a certain time has passed in an insensitive region of a cutting height target value set as a value within a predetermined range in the automatic control of the cutting height. In this case, the cutting reference height is a value stored in the control device 200 based on the detection value of the cutting height detection device 40. As described later, the relative machine height stored in the control device 200 is a calculation object of an average value, and the average value can be used as the cutting reference height.

[0155] like Fig.13 As shown, in the lifting range limitation control, the cutting reference height H0 is set as a reference value for the height of the machine body of the cutting section 5. The height of the machine body that is higher than the cutting reference height H0 by a predetermined lifting amount ΔH1 is set as the prohibited lifting height H1. In addition, the height of the machine body that is lower than the cutting reference height H0 by a predetermined lowering amount ΔH2 is set as the prohibited lowering height H2.

[0156] In the present embodiment, the rise amount ΔH1 is set to a value greater than the fall amount ΔH2. Specifically, for example, the rise amount ΔH1 is set to 50 mm, and the fall amount ΔH2 is set to 30 mm. In addition, the values ​​of the rise amount ΔH1 and the fall amount ΔH2, and the magnitude relationship between the two are not limited, but from the viewpoint of suppressing the insertion of the cutting part 5 relative to the ground, in order to ensure a certain degree of rise amount ΔH1, the rise amount ΔH1 is set to a value greater than the fall amount ΔH2.

[0157] In the lifting range limitation control, the control device 200 controls the operation of the solenoid valve 221 of the cutting lifting cylinder 18 based on the detection signal detected by the machine body height sensor 203 in such a manner that the machine body height is set to be below the prohibited lifting height H1 compared with the cutting reference height H0 on the ascending side and to be above the prohibited descending height H2 compared with the cutting reference height H0 on the descending side, thereby controlling the machine body height of the cutting section 5.

[0158] That is, when the height of the body of the harvesting unit 5 is to be raised by the automatic harvesting height control based on the detection signal of the harvesting height detection device 40 so as to be controlled to reach a height higher than the prohibited raising height H1, the raising control of the harvesting unit 5 is restricted (prohibited) by the lifting range restriction control so that the height of the body of the harvesting unit 5 does not exceed the prohibited raising height H1. Similarly, when the height of the body of the harvesting unit 5 is to be lowered by the automatic harvesting height control based on the detection signal of the harvesting height detection device 40 so as to be controlled to reach a height lower than the prohibited lowering height H2, the lowering control of the harvesting unit 5 is restricted (prohibited) by the lifting range restriction control so that the height of the body of the harvesting unit 5 does not fall below the prohibited lowering height H2.

[0159] Thus, the lifting range limiting control limits the lifting range of the cutting unit 5 within the range of the predetermined lifting amount ΔH1 and lowering amount ΔH2 relative to the cutting reference height H0. The lifting amount ΔH1 and lowering amount ΔH2 are preset and stored in the storage unit of the control device 200.

[0160] Regarding the structure for performing automatic cutting height control and lifting range limitation control as described above, the control device 200 performs control to invalidate the lifting range limitation control during a constant period of time from the start of cutting of the cutting operation, that is, at the beginning of the cutting operation. That is, the control device 200 does not perform the lifting range limitation control during a constant period of time from the start of cutting, but only performs automatic cutting height control. In addition, the state of performing automatic cutting height control is the state of selecting any control mode of the automatic cutting height mode and the automatic lifting mode.

[0161] As a first control method for disabling the lifting range limitation control at the initial stage of the harvesting operation, the control device 200 disabling the lifting range limitation control and performing only automatic harvesting height control from the start of control, i.e., the start of harvesting, to the time when the travel distance of the traveling body 4 reaches a specified distance.

[0162] like Fig.14As shown, when the combine harvester 1 starts the harvesting operation at an arbitrary starting position Q0, the harvesting start time becomes the control start time for starting the control of the harvesting section 5. Regarding the harvesting start time, the control device 200, for example, determines the timing that satisfies the following conditions as the harvesting start time. That is, (1) a prescribed condition regarding the vehicle speed of the combine harvester 1 detected by the vehicle speed sensor 201 (for example, the vehicle speed is above a constant speed) is satisfied, and (2) a prescribed condition regarding the harvesting height (height above the ground) detected by the harvesting height detection device 40 (for example, the harvesting height is below a constant height), or a prescribed condition regarding the machine height detected by the machine height sensor 203 (for example, the machine height is below a constant height) is satisfied, and (3) the operation clutch (harvesting clutch) is brought into engagement by the operation of the clutch operating member disposed on the driving unit 14.

[0163] Furthermore, the control device 200 makes the lifting range limitation control invalid and performs only the automatic cutting height control during the period from the start of cutting by the combine harvester 1 until the travel distance D of the (traveling body 4) of the combine harvester 1 relative to the starting position Q0 reaches the prescribed distance D1. That is, the travel interval E1 of the combine harvester 1 that starts the cutting operation at the starting position Q0 where the travel distance D is set to 0 from the starting position Q0 until it reaches the position Q1 where the travel distance D reaches the distance D1 is: the invalid interval of the lifting range limitation control.

[0164] exist Fig.14 In the example shown, a predetermined position substantially in the center of the front-rear direction of the traveling body 4 is used as a reference for the position of the combine harvester 1. Fig.14 In FIG. 1 , the travel distance D indicated on the horizontal axis indicates the distance the combine harvester 1 moves regardless of the traveling direction of the combine harvester 1 , and corresponds to the harvesting distance which is the travel distance after the harvesting of the combine harvester 1 starts.

[0165] The control device 200 calculates the travel distance D of the combine harvester 1 based on detection information of the vehicle speed sensor 201 that detects the rotation speed of the crawler track 3 and time information measured by a timing function of the control device 200 .

[0166] like Fig.14 As shown, when the travel distance D of the combine harvester 1 from the start of harvesting reaches the distance D1, the process of invalidating the lifting range limit control is canceled and the lifting range limit control is started. That is, in the combine harvester 1, during the harvesting distance relative to the distance D1 at the start of harvesting, the harvesting operation or travel accompanied only by the automatic harvesting height control is performed, and then the automatic harvesting height control and the lifting range limit control are performed in parallel by the control device 200, and this state continues until the harvesting is completed.

[0167] The end of harvesting is the end of control of the harvesting unit 5. Regarding the end of harvesting, the control device 200 determines that harvesting is ended when the timing of satisfying at least one of the prescribed conditions related to the vehicle speed of the combine harvester 1 detected by the vehicle speed sensor 201, the harvesting height (height above the ground) detected by the harvesting height detection device 40, and the height of the machine body detected by the machine body height sensor 203, or the timing of the working clutch (harvesting clutch) being turned into a disconnected state by the operation of the clutch operating member. Fig.14 As shown, in this example, the calculation of the harvesting distance (travel distance D) is continuously performed by the control device 200 from the start of harvesting to the end of harvesting, that is, during the harvesting operation (see arrow F1).

[0168] According to the lifting and lowering control of the harvesting unit 5 as described above, the following control is performed as a control method of the combine harvester 1. That is, regarding the control method of the combine harvester 1, the harvesting height (height above the ground) and the height above the machine body are detected, and the height of the harvesting unit 5 is controlled based on the detected harvesting height and the height above the machine body, wherein automatic harvesting height control and lifting range limitation control are performed, and the lifting range limitation control is invalidated during the period from the start of control to the time when the travel distance D of the traveling machine body 4 reaches the predetermined distance D1.

[0169] The control device 200 can calculate and update the cutting reference height H0 used for the lifting range limit control during the cutting operation. As an example of a control method in the case of calculating / updating the cutting reference height H0, the control device 200 calculates the cutting reference height H0 as an average value of the machine body height stored at predetermined time intervals and updates it at predetermined time intervals.

[0170] Specifically, if Fig.15 As shown in FIG. 1 , during the harvesting operation, each time a predetermined time Δt1 elapses, the control device 200 stores the height of the machine body detected by the machine body height sensor 203 at that time as the harvesting reference height H0. The height of the machine body is appropriately changed by the automatic harvesting height control by the harvesting height detection device 40, and the height of the machine body appropriately changed under the control of the automatic harvesting height control is detected by the machine body height sensor 203.

[0171] exist Fig.15 In A, the dotted line graph G1 shows an example of the change of the height of the machine body at each time when the predetermined time Δt1 passes. That is, the graph G1 shows the detection value (measurement value) of the height of the machine body at each time when the predetermined time Δt1 passes, and the detection value of the height of the machine body is stored in the control device 200 each time. Fig.15In the graph shown in A, the horizontal axis represents time and the vertical axis represents the height of the aircraft.

[0172] With respect to the machine height stored every time a predetermined time Δt1 passes, at each timing when the machine height is stored, the control device 200 calculates the average value of all machine height values ​​stored until that moment, thereby setting the calculated average value as the cutting reference height H0 at that moment. Fig.15 In A, a graph G2 indicated by a solid line shows an example of changes in the cutting reference height H0 calculated every time a predetermined time Δt1 elapses.

[0173] Specifically, in Fig.15 In the example shown in A, the cutting reference height H0 (reference point R1) calculated at an arbitrary time ta is the average value of the heights of the machine body (reference point R2) stored every time the predetermined time Δt1 has passed until then, including the height of the machine body detected at the time ta (reference point R2). That is, the value of the cutting reference height H0 calculated at the time ta is the value obtained by dividing the total value of all the heights of the machine body (including the height of the machine body stored at the time ta) stored every time the predetermined time Δt1 has passed from the start of cutting to the time ta by the number of times stored from the start of cutting to the time ta (including the storage at the time ta), that is, the number of times the predetermined time Δt1 has passed from the start of cutting.

[0174] The cutting reference height H0 calculated as described above is used for the lifting range limitation control. That is, the cutting reference height H0 used for the lifting range limitation control is calculated and updated every time a predetermined time Δt1 elapses.

[0175] When the cutting reference height H0 is calculated / updated in the lifting range limitation control, the lifting prohibited height H1 and the lowering prohibited height H2 in the lifting range limitation control also change in accordance with the change of the cutting reference height H0. Fig.15 In B, the graph G3 shows an example of the change of the prohibited ascent height H1 every time the predetermined time Δt1 passes, and the graph G4 shows an example of the change of the prohibited descent height H2 every time the predetermined time Δt1 passes. Fig.15 As shown in B, the prohibited elevation height H1 and prohibited descent height H2 respectively defined by the elevation amount ΔH1 and descent amount ΔH2 relative to the cutting reference height H0 change in accordance with the change of the cutting reference height H0 calculated and updated at every predetermined time Δt1.

[0176] In this way, in the control method of the combine harvester 1, a method of calculating the harvesting reference height H0 as an average value of the machine body height stored at predetermined time intervals and updating the average value at predetermined time intervals may be used.

[0177] When calculating / updating the cutting reference height H0, Fig.14 As shown, in the travel section E1 where the lifting range limit control becomes invalid, the calculation / update process of the cutting reference height H0 is not performed. Moreover, when the travel distance D of the combine harvester 1 starting from the starting position Q0 reaches a predetermined distance D1 and the invalidation of the lifting range limit control is cancelled, the calculation / update process of the cutting reference height H0 is started at the same time as the lifting range limit control is started, and it is continued until the cutting is completed (refer to arrow F2).

[0178] The second control method for controlling the lifting range limitation control to be invalid at the beginning of the harvesting operation is described. As the second control method, the control device 200 makes the lifting range limitation control invalid and performs only the automatic harvesting height control from the start of harvesting as the control start until a predetermined time has passed. That is, in the first control method, the period during which the lifting range limitation control is invalidated from the start of harvesting is specified based on the travel distance, whereas in the second control method, the period is specified based on time.

[0179] like Fig.16 As shown, when the combine harvester 1 starts the harvesting operation at an arbitrary start time T0, the start time of harvesting becomes the control start time of starting the control of the harvesting unit 5. Moreover, after the harvesting of the combine harvester 1 starts, during the period from the start time T0 to the predetermined time T1, the control device 200 makes the lifting range limitation control invalid and performs only the automatic harvesting height control. That is, the period of time J1, which is the elapsed time T from the start time T0 to the time T1, is the invalid interval of the lifting range limitation control.

[0180] like Fig.16 As shown, when the time J1 elapses from the start of harvesting and the time T1 is reached, the process of invalidating the lifting range limit control is canceled and the lifting range limit control is started. That is, in the combine harvester 1, during the time J1 from the start of harvesting, harvesting operation or driving accompanied only by automatic harvesting height control is performed, and then the automatic harvesting height control and the lifting range limit control are performed in parallel by the control device 200, and this state continues until the harvesting is completed. As for other control contents, they are the same as the first control mode, so the description is omitted.

[0181] According to the lifting and lowering control of the harvesting section 5 as described above, the following control is performed as a control method of the combine harvester 1. That is, regarding the control method of the combine harvester 1, the harvesting height (height above the ground) and the height above the machine body are detected, and the height of the harvesting section 5 is controlled based on the detected harvesting height and the height above the machine body, wherein automatic harvesting height control and lifting range limitation control are performed, and the lifting range limitation control is invalidated during the period from the start of control until a predetermined time has passed.

[0182] The third control mode of control for disabling the lifting range limit control at the beginning of the harvesting operation will be described. As the third control mode, the control device 200 disabling the lifting range limit control and performing only the automatic harvesting height control from the start of harvesting as the control start until the vehicle speed of the traveling machine body 4 reaches a predetermined speed. That is, in the first control mode, the period for disabling the lifting range limit control from the start of harvesting is defined based on the travel distance, whereas in the third control mode, the period is defined based on the vehicle speed.

[0183] like Fig.17 As shown, when the combine harvester 1 starts the harvesting operation at an arbitrary vehicle speed V0, the start of harvesting becomes the start of the control of the harvesting unit 5. Moreover, after the harvesting of the combine harvester 1 starts until the vehicle speed V increases from the vehicle speed V0 and reaches the prescribed vehicle speed V1, the control device 200 makes the lifting range limitation control invalid and only performs the automatic harvesting height control. That is, the interval K1 until the vehicle speed V increases from the vehicle speed V0 and reaches the vehicle speed V1 is the invalid interval of the lifting range limitation control. In addition, the vehicle speed V is the vehicle speed of the combine harvester 1 detected by the vehicle speed sensor 201. In addition, the vehicle speed V0 at the start of harvesting can be a state where the vehicle speed V is 0, that is, a driving stop state of the combine harvester 1.

[0184] like Fig.17 As shown, at the timing when the vehicle speed V increases from the vehicle speed V0 and reaches the vehicle speed V1 from the start of harvesting, the process of invalidating the lifting range limit control is canceled and the lifting range limit control is started. That is, with respect to the combine harvester 1, from the start of harvesting until the vehicle speed V increases to the vehicle speed V1, harvesting operation or driving accompanied only by automatic harvesting height control is performed, and then the automatic harvesting height control and the lifting range limit control are performed in parallel by the control device 200, and this state continues until the harvesting is completed. As for other control contents, they are the same as those of the first control mode, and therefore the description thereof is omitted.

[0185] According to the lifting and lowering control of the harvesting unit 5 as described above, the following control is performed as a control method of the combine harvester 1. That is, regarding the control method of the combine harvester 1, the harvesting height (height above the ground) and the height above the machine body are detected, and the height of the harvesting unit 5 is controlled based on the detected harvesting height and the height above the machine body, wherein automatic harvesting height control and lifting range limitation control are performed, and the lifting range limitation control is invalidated from the start of control until the vehicle speed of the traveling machine body 4 reaches a predetermined speed.

[0186] use Fig.18 The flowchart shown in the figure explains an example of the control process regarding the cutting reference height in the above-mentioned lifting range limiting control. The CPU of the control device 200 reads and executes a predetermined control program stored in a storage device such as RAM to perform the control process described below.

[0187] like Fig.18 As shown, first, when calculating / updating the cutting reference height, it is determined whether any one of the following conditions is satisfied. That is, it is determined whether any one of "cutting manual raising operation", "cutting manual lowering operation", "cutting automatic raising", "cutting automatic setting" and "cutting height adjustment dial is turned" is satisfied (S10).

[0188] In step S10, "manual harvesting raising operation" and "manual harvesting lowering operation" correspond to the raising operation and lowering operation by manual operation of the harvesting lifting rod 35, respectively. "Automatic harvesting raising" means that the harvesting unit 5 is automatically raising by the operation of the automatic harvesting raising switch 36. "Automatic harvesting setting" means that the harvesting unit 5 is automatically lowering by the operation of the automatic harvesting setting switch 37. "Swishing the harvesting height adjustment dial" means changing the harvesting height target value by operating the harvesting height adjustment dial 202.

[0189] In step S10, when it is determined that any of the above conditions is satisfied (S10, Yes), the following processing is performed without calculating / updating the cutting reference height. That is, the cutting reference height is not set (not set), the value stored in the buffer, that is, the value of the machine height stored in the control device 200 up to this point is cleared, the lifting stop time is reset to 0 (S20), and the processing ends. In the control processing regarding the cutting reference height, the control device 200 always measures the time when the cutting section 5 is not lifted as the lifting stop time based on the control signal of the control valve of the cutting lifting cylinder 18.

[0190] On the other hand, in step S10, when it is determined that none of the above conditions is satisfied (S10, No), it is determined whether the cutting reference height is not set (S30). In step S30, when it is determined that the cutting reference height is not set (S30, Yes), it is determined whether the following conditions are satisfied. That is, it is determined whether all the conditions of "cutting distance is above a constant value", "machine body straight-ahead speed is above a constant value", "vertical conveying ear stem detection sensor is turned on", and "cutting height is within the target range of automatic cutting height control" are satisfied (S40).

[0191] In step S40, "the harvesting distance is greater than a constant value" means that the travel distance of the combine harvester 1 after the start of harvesting is greater than a predetermined distance. In addition, as described above, the travel distance is calculated based on the detection information of the vehicle speed sensor 201 and the elapsed time information. "The straight-moving speed of the machine body is greater than a constant value" means that the speed detected by the vehicle speed sensor 201 in the straight-moving state of the machine body is greater than a predetermined speed.

[0192] Similarly, in step S40, “the vertical conveying spikelet detection sensor is turned on” means that the spikelet detection sensor 204 (see FIG. 204 ) detects the presence or absence of spikelets harvested by the harvesting section 5. Fig.10 ) is in an on state. The spike stalk detection sensor 204 is a contact sensor as follows: for example, it is arranged in the conveying path based on the longitudinal conveying of the spike stalk conveying device 25 in the cutting section 5, and detects the presence or absence of the spike stalk according to the presence or absence of contact with the spike stalk. However, the type of the spike stalk detection sensor 204 is not limited. The detection signal of the spike stalk detection sensor 204 is input to the control device 200. The on state of the spike stalk detection sensor 204 means that the spike stalks cut in the cutting section 5 are conveyed in the spike stalk conveying device 25, which corresponds to the cutting operation.

[0193] Similarly, in step S40, "the cutting height is within the target range of the automatic cutting height control" means that the cutting height (height above the ground) detected by the cutting height detection device 40 is within the range of the cutting height target value (within the insensitive region) when the cutting height target value is set to a value within a predetermined range in the automatic cutting height control. When this condition is satisfied, the lifting and lowering of the cutting unit 5 is stopped in the automatic cutting height control.

[0194] In step S40 , when it is not determined that all of the above conditions are satisfied ( S40 , No), that is, when at least one of the above conditions is not satisfied, the process is terminated.

[0195] On the other hand, in step S40, when it is determined that all of the above conditions are satisfied (S40, Yes), the current (at that moment) height of the machine body is stored in the buffer (S50), and the cutting reference height is calculated (S60) as the average value of the height of the machine body stored in the control device 200 so far. The cutting reference height calculated here is updated as the cutting reference height for the lifting range limitation control. The processing ends in this way.

[0196] Returning to step S30, when it is determined that the cutting reference height is not set (S30, No), that is, when a predetermined value is set as the cutting reference height, it is determined whether the following conditions are satisfied. That is, it is determined whether all the conditions of "the straight-moving speed of the machine body is above a constant value", "the cutting height is below a constant value", "the cutting height is within the target range of the automatic cutting height control", "the machine body height is below the prohibited ascending height", and "the machine body height is above the prohibited descending height" are satisfied (S70).

[0197] In step S70, "the cutting height is below a constant value" means that the cutting height (height above the ground) detected by the cutting height detection device 40 is below a predetermined cutting height. This condition is used, for example, to exclude a state where the cutting height detection device 40 is completely floating from the ground 30 (a state where the grounding body 42 is not grounded). In addition, "the height of the machine body is below the prohibited ascent height" means that the height of the machine body detected by the machine body height sensor 203 is below the prohibited ascent height H1 in the above-mentioned lifting range limiting control, and "the height of the machine body is above the prohibited descent height" means that the height of the machine body is above the prohibited descent height H2 in the lifting range limiting control.

[0198] In step S70, when it is determined that all of the above conditions are satisfied (S70, Yes), the timing of the lifting stop time is started (S80). Furthermore, it is determined whether the lifting stop time reaches a constant time or longer (S90). When it is determined that the lifting stop time reaches a constant time or longer (S90, Yes), the current height of the machine body is stored in the buffer and the lifting stop time is reset to 0 (S100). That is, when the height of the cutting section 5 is within the range of the prohibited height of the lifting / lowering of the lifting range limit control and within the insensitive area of ​​the automatic cutting height control for a constant time during driving at a speed higher than the constant vehicle speed, the height of the machine body at that time is stored. Furthermore, the cutting reference height is calculated as the average value of the values ​​of the height of the machine body stored in the control device 200 so far (S60). In step S70, when it is not determined that all of the above conditions are satisfied (S40, No), the timing of the lifting stop time is not started and the process proceeds to step S90.

[0199] In step S90, if it is not determined that the lifting stop time has reached or exceeded the constant time (S90, No), the cutting reference height is calculated as the average value of the height of the machine body stored in the control device 200 so far (S60), and the cutting reference height is updated. That is, in step S90, as long as the lifting stop time has not exceeded the constant time, the height of the machine body at that time is not stored, and the average value of the height of the machine body is calculated based on the information stored so far as the cutting reference height. The constant time in step S90 is an example after all, and is about 1 second to several seconds.

[0200] The calculation and updating of the cutting reference height in the lifting range limitation control are performed through the above series of control processing.

[0201] According to the combine harvester 1 having the above-described configuration and the control method of the combine harvester 1, it is possible to suppress the harvesting section 5 from coming into contact with or digging into the ground, and to suppress harvest residues.

[0202] In the automatic cutting height control, for example, if the cutting section 5 is caught in a concave portion of the ground, the ground detected by the cutting height detection device 40 is partially lowered, so it is mistakenly believed that the height of the cutting section 5 relative to the ground (height to the ground) has increased. In this case, the lowering control of the cutting section 5 may work and the dividing plate 21 of the cutting section 5 may be inserted into the ground.

[0203] In order to prevent such malfunction, for example, the following lifting control can be considered: the height of the machine body when the lifting control of the harvesting unit is in effect is stored, and in the automatic harvesting height control, when the height of the machine body is lower than the stored height of the machine body (the height that prohibits descending), the descending control of the harvesting unit is prohibited. However, according to this lifting control, there are the following problems.

[0204] like Fig.19 As shown in A, for example, when the combine harvester 1 enters a field, the combine harvester 1 is sometimes located on a continuous inclined surface 211 that is lower in the front and higher in the back relative to a flat field 210, and the machine body becomes tilted forward, and the cutting section 5 is formed so as to be located on the field 210. In this state, the height of the machine body when the rising control of the cutting section 5 is in effect is detected by the cutting height detection device 40, and the height of the machine body becomes higher than the height of the machine body that should have been detected in accordance with the situation that the inclined surface 211 is located on the upper side relative to the field 210, and this value is stored as the prohibited descent height. In this case, as Fig.19 As shown in B, during the harvesting operation on the flat field 210, the harvesting unit 5 cannot be positioned at the target harvesting height due to the prohibited descent height stored as a height higher than necessary.

[0205] In addition, if Fig. 20As shown in A, at the beginning of the harvesting operation (start of harvesting), it is conceivable that, for example, the harvesting height detection device 40 contacts the crop 212 in the field, and the rising control is activated by the detection of the harvesting height detection device 40 before the harvesting section 5 reaches the target height. In this case, Fig. 20 B, the height is mistakenly stored as the prohibited descending height, and the cutting unit 5 cannot be located at the target cutting height. In addition, not limited to the start of cutting, even in the middle of the cutting operation, the cutting height detection device 40 may climb onto the crop 212, thereby accidentally causing the ascending control to function.

[0206] Therefore, in the combine harvester 1 according to the present embodiment, as the lifting and lowering control of the harvesting section 5, the lifting and lowering range limiting control is invalidated and the automatic harvesting height control is performed in a constant interval defined based on at least one of the travel distance, the elapsed time, and the increase in the vehicle speed of the traveling machine body 4 since the start of the control. That is, after the harvesting operation is performed for a constant period in the state of performing the automatic harvesting height control from the start of harvesting, the lifting and lowering range limiting control is started.

[0207] According to this structure, the mowing operation can be stably performed in a stable state of the field, the cutting unit 5 can be prevented from contacting or inserting into the ground, and the poor mowing situation such as mowing residue can be prevented. That is, in a state where the posture of the machine body is unstable, the lifting range limiting control that limits the lifting range of the cutting unit 5 is not performed, and the automatic mowing height control based on the cutting height detection device 40 is performed in a state where there is no limitation on the lifting range of the cutting unit 5. At the timing when the machine body is stable (for example, when the vehicle speed reaches a certain degree of high speed), the lifting range limiting control is started, so that, for example, when the cutting height detection device 40 detects the unevenness of the field, the cutting unit 5 can be prevented from contacting or inserting into the ground.

[0208] In addition, the lifting range limitation control is performed in parallel with the automatic cutting height control. A prohibited descending height is set for the lifting range of the cutting unit 5, so as to avoid, for example, the cutting unit 5 being inserted into a recessed portion of the ground, and a prohibited ascending height is set for the lifting range of the cutting unit 5, so as to avoid the cutting unit 5 climbing up toward the crops and causing the cutting unit 5 to rise.

[0209] In addition, the main machine height that serves as the reference for the prohibited descent height and the prohibited ascent height is calculated / updated and stored as the reference height for harvesting whenever the prescribed condition is satisfied during the harvesting operation. The storage control of the reference height for harvesting is performed by performing the invalidation control of the lifting range limitation control at the start of harvesting as described above, thereby preventing the storage of an erroneous value when the combine harvester 1 enters the field and starts harvesting, and the height of the harvesting unit 5 can follow the target height.

[0210] In addition, regarding the calculation / update of the cutting reference height, the average value of the machine height stored as the cutting reference height is used as the cutting reference height. According to this structure, even if a special value is stored as the cutting reference height due to the unevenness of the ground, the value can be averaged by using the average value, so that the influence of the stored value of the special value can be reduced. As a result, the insertion of the cutting unit 5 relative to the ground and the cutting residue can be effectively suppressed, and the operability of the cutting unit 5 can be improved.

[0211] The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment. Therefore, in addition to the above embodiment, various changes can be made according to the design, etc. as long as they do not deviate from the scope of the technical idea involved in the present invention. In addition, the effects recorded in the present disclosure are examples after all, and are not limited. In addition, other effects may also be possible.

[0212] The present technology can adopt the following structures. In addition, the structures described below can be selected and combined arbitrarily.

[0213] (1) A combine harvester comprising: a harvesting section arranged to be able to be raised and lowered relative to a traveling machine body; a harvesting height detection device for detecting the height of the harvesting section relative to the ground, i.e., the harvesting height; a machine body height detection device for detecting the height of the harvesting section relative to the traveling machine body, i.e., the machine body height; and a control device for controlling the height of the harvesting section based on detection signals of the harvesting height detection device and the machine body height detection device, characterized in that:

[0214] The control device performs the following control:

[0215] cutting height control in which the height of the cutting portion is controlled so that the cutting height detected by the cutting height detection device reaches a predetermined target value; and

[0216] a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a reference value of the height of the machine body detected by the machine body height detecting device, i.e., a cutting reference height;

[0217] The lifting range limitation control is disabled from the start of control until the travel distance of the travel machine reaches a predetermined distance or until a predetermined time has passed.

[0218] (2) A combine harvester comprising: a harvesting section arranged to be able to be raised and lowered relative to a traveling machine body; a harvesting height detection device for detecting the height of the harvesting section relative to the ground, i.e., the harvesting height; a machine body height detection device for detecting the height of the harvesting section relative to the traveling machine body, i.e., the machine body height; and a control device for controlling the height of the harvesting section based on detection signals of the harvesting height detection device and the machine body height detection device, characterized in that:

[0219] The control device performs the following control:

[0220] cutting height control in which the height of the cutting portion is controlled so that the cutting height detected by the cutting height detection device reaches a predetermined target value; and

[0221] a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a reference value of the height of the machine body detected by the machine body height detecting device, i.e., a cutting reference height;

[0222] The raising / lowering range limiting control is disabled during a period from when the control is started until the vehicle speed of the traveling machine reaches a predetermined speed.

[0223] (3) The combine harvester according to (1) or (2), characterized in that:

[0224] The control device calculates the cutting reference height as an average value of the machine body height stored at predetermined time intervals and updates the calculated cutting reference height at predetermined time intervals.

[0225] (4) A control method for a combine harvester, comprising detecting a height of a harvesting unit relative to the ground, i.e., a harvesting height, and a height of the harvesting unit relative to a traveling machine body, i.e., a relative machine body height, and controlling the height of the harvesting unit based on the detected harvesting height and relative machine body height, characterized in that:

[0226] Perform the following control:

[0227] cutting height control in which the height of the cutting portion is controlled so that the detected cutting height reaches a predetermined target value; and

[0228] a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a cutting reference height, which is a reference value for the height of the machine body;

[0229] The lifting range limitation control is disabled from the start of control until the travel distance of the travel machine reaches a predetermined distance or until a predetermined time has passed.

[0230] (5) A control method for a combine harvester, comprising detecting a height of a harvesting unit relative to the ground, i.e., a harvesting height, and a height of the harvesting unit relative to a traveling machine body, i.e., a relative machine body height, and controlling the height of the harvesting unit based on the detected harvesting height and relative machine body height, characterized in that:

[0231] Perform the following control:

[0232] cutting height control in which the height of the cutting portion is controlled so that the detected cutting height reaches a predetermined target value; and

[0233] a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a cutting reference height, which is a reference value for the height of the machine body;

[0234] The lifting and lowering range limiting control is disabled during a period from when the control is started until the vehicle speed of the traveling machine reaches a predetermined speed.

[0235] (6) The control method for a combine harvester according to (4) or (5), characterized in that:

[0236] The cutting reference height is calculated as an average value of the machine body height stored at predetermined time intervals and updated at predetermined time intervals.

Claims

1. A combine harvester, comprising: a harvesting section arranged to be able to rise and fall relative to a traveling machine body; a harvesting height detection device for detecting the height of the harvesting section relative to the ground, i.e., the harvesting height; a machine body height detection device for detecting the height of the harvesting section relative to the traveling machine body, i.e., the machine body height; and a control device for controlling the height of the harvesting section based on detection signals of the harvesting height detection device and the machine body height detection device, characterized in that: The control device performs the following control: cutting height control in which the height of the cutting portion is controlled so that the cutting height detected by the cutting height detection device reaches a predetermined target value; and a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a reference value of the height of the machine body detected by the machine body height detecting device, i.e., a cutting reference height; The lifting range limitation control is disabled from the start of control until the travel distance of the travel machine reaches a predetermined distance or until a predetermined time has passed.

2. A combine harvester, comprising: a harvesting section which is arranged to be able to rise and fall relative to a traveling machine body; a harvesting height detection device for detecting the height of the harvesting section relative to the ground, i.e., the harvesting height; a machine body height detection device for detecting the height of the harvesting section relative to the traveling machine body, i.e., the machine body height; and a control device for controlling the height of the harvesting section based on detection signals of the harvesting height detection device and the machine body height detection device, characterized in that: The control device performs the following control: cutting height control in which the height of the cutting portion is controlled so that the cutting height detected by the cutting height detection device reaches a predetermined target value; and a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a reference value of the height of the machine body detected by the machine body height detecting device, i.e., a cutting reference height; The raising / lowering range limiting control is disabled during a period from when the control is started until the vehicle speed of the traveling machine reaches a predetermined speed.

3. The combine harvester according to claim 1 or claim 2, characterized in that: The control device calculates the cutting reference height as an average value of the machine body height stored at predetermined time intervals and updates the calculated cutting reference height at predetermined time intervals.

4. A control method for a combine harvester, comprising detecting a height of a harvesting unit relative to the ground, i.e., a harvesting height, and a height of the harvesting unit relative to a traveling machine body, i.e., a height relative to the machine body, and controlling the height of the harvesting unit based on the detected harvesting height and the height relative to the machine body, wherein: Perform the following control: cutting height control in which the height of the cutting portion is controlled so that the detected cutting height reaches a predetermined target value; and a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a cutting reference height, which is a reference value for the height of the machine body; The lifting range limitation control is disabled from the start of the control until the travel distance of the travel machine reaches a predetermined distance or until a predetermined time has passed.

5. A control method for a combine harvester, comprising detecting a height of a harvesting unit above the ground, i.e., a harvesting height, and a height of the harvesting unit relative to a traveling machine body, i.e., a relative machine body height, and controlling the height of the harvesting unit based on the detected harvesting height and relative machine body height, wherein: Perform the following control: cutting height control in which the height of the cutting portion is controlled so that the detected cutting height reaches a predetermined target value; and a lifting range limiting control in which the lifting range of the cutting section is limited within a range of a predetermined lifting amount and a predetermined lowering amount relative to a cutting reference height, which is a reference value for the height of the machine body; The lifting and lowering range limiting control is disabled during a period from when the control is started until the vehicle speed of the traveling machine reaches a predetermined speed.

6. The control method for a combine harvester according to claim 4 or claim 5, characterized in that: The cutting reference height is calculated as an average value of the machine body height stored at predetermined time intervals and updated at predetermined time intervals.

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